title:
Behaviors of positively charged fine particles in a cross field sheath
  between magnetized double plasmas

abstract:
  Dependencies of levitation position of positively charged fine-particles on
plasma parameters are investigated. The charges on the particles become
positive in a cross-field sheath between magnetized double plasmas with
different potentials separated vertically by horizontal magnetic field, because
ion current flowing from a lower high-potential plasma surpasses electron
current coming across the magnetic field from an upper low-potential plasma.
  From measurement of the resonance frequency of the particles driven by
external oscillating electric field, the charge on particle is estimated to be
of the order of 10e2. Variation of particle levitation positions can be
explained by the change of the charges.


title:
The environment effect on operation of in-vessel mirrors for plasma
  diagnostics in fusion devices

abstract:
  First mirrors will be the plasma facing components of optical diagnostic
systems in ITER. Mirror surfaces will undergo modification caused by erosion
and re-deposition processes [1,2]. As a consequence, the mirror performance may
be changed and may deteriorate [3,4]. In the divertor region it may also be
obscured by deposition [5-7]. The limited access to in-vessel components of
ITER calls for testing the mirror materials in present day devices in order to
gather information on the material damage and degradation of the mirror
performance, i.e. reflectivity. A dedicated experimental programme, First
Mirror Test (FMT), has been initiated at the JET tokamak within the framework
Tritium Retention Studies (TRS).


title: The optical calcium frequency standards of PTB and NIST

abstract:
  We describe the current status of the Ca optical frequency standards with
laser-cooled neutral atoms realized in two different laboratories for the
purpose of developing a possible future optical atomic clock.
  Frequency measurements performed at the Physikalisch-Technische Bundesanstalt
(PTB) and the National Institute of Standards and Technology (NIST) make the
frequency of the clock transition of 40Ca one of the best known optical
frequencies (relative uncertainty 1.2e-14) and the measurements of this
frequency in both laboratories agree to well within their respective
uncertainties.
  Prospects for improvement by orders of magnitude in the relative uncertainty
of the standard look feasible.


title:
Efficiency enhancement of organic based Light Emitting Diodes using a
  scattering layer

abstract:
  This paper presents an investigation of organic LED extraction efficiency
enhancement using a low refractive index scattering layer. A scattering model
is developed based on rigorous electromagnetic modelling techniques. The model
accounts for proportions of scattered guided and radiation modes as well as the
efficiencies with which emitted and scattered light are extracted. Constrained
optimisation techniques are implemeneted for a single operation wavelength to
maximise the extraction efficiency of a generic OLED device. Calculations show
that a 2 fold efficiency enhancement is achievable with a correctly engineered
scattering layer. The detailed analysis of the enhancement mechanism highlights
ways in which this scheme could be improved.


title: Bound-state corrections in laser-induced nonsequential double ionization

abstract:
  We perform a systematic analysis of how nonsequential double ionization in
intense, linearly polarized laser fields is influenced by the initial states in
which both electrons are bound, and by the residual ionic potential. We assume
that the second electron is released by electron-impact ionization of the first
electron with its parent ion, using an S-Matrix approach. We work within the
Strong-Field Approximation, and compute differential electron momentum
distributions using saddle-point methods. Specifically, we consider electrons
in $1s$, $2p$, $3p$ and localized states, which are released by either a
contact or a Coulomb-type interaction. We also perform an adequate treatment of
the bound-state singularity which is present in this framework. We show that
the momentum distributions are very sensitive with respect to spatially
extended or localized wave functions, but are not considerably influenced by
their shape. Furthermore, the modifications performed in order to overcome the
bound-state singularity do not significantly alter the momentum distributions,
apart from a minor suppression in the region of small momenta. The only radical
changes occur if one employs effective form factors, which take into account
the presence of the residual ion upon rescattering. If the ionic potential is
of contact type, it outweighs the spreading caused by a long-range
electron-electron interaction, or by spatially extended bound states. This
leads to momentum distributions which exhibit a very good agreement with the
existing experiments.


title: Atom Interferometry in a Vertical Optical Lattice

abstract:
  We have studied the interference of degenerate quantum gases in a vertical
optical lattice. The coherence of the atoms leads to an interference pattern
when the atoms are released from the lattice. This has been shown for a
Bose-Einstein condensate in early experiments. Here we demonstrate that also
for fermions an interference pattern can be observed provided that the momentum
distribution is smaller then the recoil momentum of the lattice. Special
attention is given to the role of interactions which wash out the interference
pattern for a condensate but do not affect a spin polarized Fermi gas, where
collisions at ultra cold temperatures are forbidden. Comparing the interference
of the two quantum gases we find a clear superiority of fermions for trapped
atom interferometry.


title: Some contributions to the theory of edge waves

abstract: A new theory of edge waves over a slowly varying depth.


title:
Similarity for ultra-relativistic laser plasmas and the optimal
  acceleration regime

abstract:
  A similarity theory is developed for ultra-relativistic laser-plasmas. It is
shown that the most fundamental S-similarity is valid for both under- and
overdense plasmas. Optimal scalings for laser wake field electron acceleration
are obtained heuristically. The strong message of the present work is that the
bubble acceleration regime [see Pukhov, Meyer-ter-Vehn, Appl. Phys. B, vol. 74,
355 (2002)] satisfies these optimal scalings.


title:
Interrogation of a fiber Fabry-Perot sensor by current modulation of a
  diode laser

abstract:
  We present a method for remote interrogation of passive fiber Bragg grating
Fabry-Perot resonators, employing current modulation of the diode laser source.
With the presence of both RF amplitude and frequency modulation, it is a
variant of the ultra-sensitive Pound-Drever-Hall laser frequency locking
technique. We demonstrate that current modulation and interferometric
demodulation removes the need for a phase modulator in the sensing
architecture.


title:
Phase-sensitive interrogation of fiber Bragg grating resonators for
  sensing applications

abstract:
  We discuss a phase-sensitive technique for remote interrogation of passive
Bragg grating Fabry-Perot resonators. It is based on Pound-Drever-Hall laser
frequency locking, using radio-frequency phase modulation sidebands to derive
an error signal from the complex optical response, near resonance, of a
Fabry-Perot interferometer. We examine how modulation frequency and resonance
bandwidth affect this error signal. Experimental results are presented that
demonstrate when the laser is locked, this method detects differential phase
shifts in the optical carrier relative to its sidebands, due to minute fiber
optical path displacements.


title: Lateral shift of the transmitted light beam through a left-handed slab

abstract:
  It is reported that when a light beam travels through a slab of left-handed
medium in the air, the lateral shift of the transmitted beam can be negative as
well as positive. The necessary condition for the lateral shift to be positive
is given. The validity of the stationary-phase approach is demonstrated by
numerical simulations for a Gaussian-shaped beam. A restriction to the slab's
thickness is provided that is necessary for the beam to retain its profile in
the traveling. It is shown that the lateral shift of the reflected beam is
equal to that of the transmitted beam in the symmetric configuration.


title:
Deformation principle as foundation of physical geometry and its
  application to space-time geometry

abstract:
  Physical geometry studies mutual disposition of geometrical objects and
points in space, or space-time, which is described by the distance function d,
or by the world function \sigma =d^{2}/2. One suggests a new general method of
the physical geometry construction. The proper Euclidean geometry is described
in terms of its world function \sigma_E. Any physical geometry G is obtained
from the Euclidean geometry as a result of replacement of the Euclidean world
function \sigma_E by the world function \sigma of G. This method is very simple
and effective. It introduces a new geometric property: nondegeneracy of
geometry. Using this method, one can construct deterministic space-time
geometries with primordially stochastic motion of free particles and
geometrized particle mass. Such a space-time geometry defined properly (with
quantum constant as an attribute of geometry) allows one to explain quantum
effects as a result of the statistical description of the stochastic particle
motion (without a use of quantum principles).


title:
Importance of electronic self-consistency in the TDDFT based treatment
  of nonadiabatic molecular dynamics

abstract:
  A mixed quantum-classical approach to simulate the coupled dynamics of
electrons and nuclei in nanoscale molecular systems is presented. The method
relies on a second order expansion of the Lagrangian in time-dependent density
functional theory (TDDFT) around a suitable reference density. We show that the
inclusion of the second order term renders the method a self-consistent scheme
and improves the calculated optical spectra of molecules by a proper treatment
of the coupled response. In the application to ion-fullerene collisions, the
inclusion of self-consistency is found to be crucial for a correct description
of the charge transfer between projectile and target. For a model of the
photoreceptor in retinal proteins, nonadiabatic molecular dynamics simulations
are performed and reveal problems of TDDFT in the prediction of intra-molecular
charge transfer excitations.


title:
Generalized Boltzmann Equation: Slip-No -Slip Dynamic Transition in
  Flows of Strongly Non-Linear Fluids

abstract:
  The Navier-Stokes equations, are understood as the result of the low-order
expansion in powers of dimensionless rate of strain $\eta_{ij}=\tau_{0}S_{ij}$,
where $\tau_{0}$ is the microscopic relaxation time of a close-to-
thermodynamic equilibrium fluid. In strongly sheared non-equilibrium fluids
where $|\eta_{ij}|\geq 1$, the hydrodynamic description breaks down.
  According to Bogolubov's conjecture, strongly non-equlibrium systems are
characterized by an hierarchy of relaxation times corresponding to various
stages of the relaxation process. A "hydro-kinetic" equation with the
relaxation time involving both molecular and hydrodynamic components proposed
in this paper, reflects qualitative aspects of Bogolubov's hierarchy. It is
shown that, applied to wall flows, this equation leads to qualitatively correct
results in an extremely wide range of parameter $\eta$-variation. Among other
features, it predicts the onset of slip velocity at the wall as an instability
of the corresponding hydrodynamic approximation.


title: Mechanical Resonance of embedded cluster

abstract:
  Embedded clusters, which are embedded in bulk materials and different from
the surroundings in structures, should be common in materials. This paper
studies resonance of such clusters. This work is stimulated by a recent
experimental observation that some localized clusters behavior like fluid at
the mesoscopic scale in many solid materials [Science in China(Series B). 46,
176 (2003)]. We argue that the phenomenon is just a vivid illustration of
resonance of embedded clusters, driven by ubiquitous microwaves. Because the
underlying mechanism is fundamental and embedded structures are usual, the
phenomenon would have great significance in material physics.


title:
Pump-probe differencing technique for cavity-enhanced, noise-canceling
  saturation laser spectroscopy

abstract:
  We present an experimental technique enabling mechanical-noise free,
cavity-enhanced frequency measurements of an atomic transition and its
hyperfine structure. We employ the 532nm frequency doubled output from a Nd:YAG
laser and an iodine vapour cell. The cell is placed in a traveling-wave
Fabry-Perot interferometer (FPI) with counter-propagating pump and probe beams.
The FPI is locked using the Pound-Drever-Hall (PDH) technique. Mechanical noise
is rejected by differencing pump and probe signals. In addition, this
differenced error signal gives a sensitive measure of differential
non-linearity within the FPI.


title:
Atomic transfers between implanted bioceramics and tissues in
  orthopaedics surgery

abstract:
  We study transfers of ions and debris from bioceramics implanted in bone
sites. A contamination of surrounding tissues may play a major role in aseptic
loosening of the implant. For these reasons, bioceramics require studies of
biocompatibility and biofunctionality . So, in addition to in vitro studies of
bioceramics, it is essential to implant them in vivo to know body reactions. We
measured the concentration of mineral elements at different time intervals
after implantation over a whole cross-section. We found a discontinuity of the
mineral elements (Ca, P, Sr, Zn, Fe) at the interface between the implant and
the receiver. The osseous attack is not global but, on the contrary,
centripetal. Moreover, the fit of the concentration time course indicates that
the kinetics of ossification is different for each atomic element and
characterizes a distinct biological phenomenon


title:
The Lorentz Transformation Sign Ambiguity and Its Relation to Measured
  Faster-than-c Photon Speeds

abstract:
  It is shown that time intervals Delta t' measured for photons moving with
speed v > c can be of the same sign for all observers according to special
relativity, thereby avoiding any violation of Einstein causality. Previous
assertions to the contrary have led to unnecessarily complicated
interpretations of experiments which indicate that single photons do travel
with faster-than-c speeds in regions of anomalous dispersion


title:
Use of Hamilton's canonical equations to rectify Newton's corpuscular
  theory of light: A missed opportunity

abstract:
  The erroneous prediction of the speed of light in dispersive media has been
looked upon historically as unequivocal proof that Newton's corpuscular theory
is incorrect. Examination of his arguments shows that they were only directly
applicable to the momentum of photons, however, leaving open the possibility
that the cause of his mistake was the unavailability of a suitable mechanical
theory to enable a correct light speed prediction, rather than his use of a
particle model. It is shown that Hamilton's canonical equations of motion
remove Newton's error quantitatively, and also lead to the most basic formulas
of quantum mechanics without reference to any of the pioneering experiments of
the late nineteenth century. An alternative formulation of the wave-particle
duality principle is then suggested which allows the phenomena of interference
and diffraction to be understood in terms of statistical distributions of large
populations of photons or other particles.


title:
On a possible dynamical scenario leading to a generalised Gamma
  distribution

abstract:
  In this report I present a possible scenario which can lead to the emergence
of a generalised Gamma distribution first presented by R. Osorio et al. as the
distribution of traded volumes of stocks in financial markets. This propose is
related with superstatics and the notion of moving average commonly used in
econometrics.


title:
Modulated dust-acoustic wave packets in a plasma with non-isothermal
  electrons and ions

abstract:
  Nonlinear self-modulation of the dust acoustic waves is studied, in the
presence of non-thermal (non-Maxwellian) ion and electron populations. By
employing a multiple scale technique, a nonlinear Schrodinger-type equation
(NLSE) is derived for the wave amplitude. The influence of non-thermality, in
addition to obliqueness (between the propagation and modulation directions), on
the conditions for modulational instability to occur is discussed. Different
types of localized solutions (envelope excitations) which may possibly occur
are discussed, and the dependence of their characteristics on physical
parameters is traced. The ion deviation from a Maxwellian distribution comes
out to be more important than the electron analogous deviation alone. Both
yield a de-stabilizing effect on (the amplitude of) DAWs propagating in a dusty
plasma with negative dust grains. The opposite effect, namely a tendency
towards amplitude stabilization, is found for the case of positively charged
dust presence in the plasma.


title: Manipulation of ultracold atomic mixtures using microwave techniques

abstract:
  We used microwave radiation to evaporatively cool a mixture of of 133Cs and
87Rb atoms in a magnetic trap. A mixture composed of an equal number (around
10^4) of Rb and Cs atoms in their doubly polarized states at ultracold
temperatures was prepared. We also used microwaves to selectively evaporate
atoms in different Zeeman states.


title:
Constraints on the Size of the Smallest Triggering Earthquake from the
  ETAS Model, Baath's Law, and Observed Aftershock Sequences

abstract:
  The physics of earthquake triggering together with simple assumptions of
self-similarity impose the existence of a minimum magnitude m0 below which
earthquakes do not trigger other earthquakes. Noting that the magnitude md of
completeness of seismic catalogs has no reason to be the same as the magnitude
m0 of the smallest triggering earthquake, we use quantitative fits and maximum
likelihood inversions of observed aftershock sequences as well as Baath's law,
compare with ETAS model predictions and thereby constrain the value of m0. We
show that the branching ratio $n$ (average number of triggered earthquake per
earthquake also equal to the fraction of aftershocks in seismic catalogs) is
the key parameter controlling the minimum triggering magnitude m0. Conversely,
physical upper bounds for m0 derived from state- and velocity-weakening
friction indicate that at least 60 to 70 percent of all earthquakes are
aftershocks.


title:
Indian monsoon rainfall is higher in epochs of higher solar activity: a
  wavelet cross-spectral analysis

abstract:
  Using the Morlet continuous wavelet transform on data over the period
1871-1990, it is found that the global wavelet cross spectra between two solar
activity indices and seven major Indian monsoon rainfall time series show
significant power around the period of the 11 year solar cycle, passing the
$\chi^2$ test of significance proposed by Torrence and Compo (1998) at levels
exceeding 95% in 10 out of the 14 cases studied. Furthermore two distinct
epochs are found in the computed cross-spectrum, the transition between them
occurring around the decade 1915-1925, beyond which solar activity parameters
show a significant increase. By comparison between selected periods of three
cycles in solar activity in each of the two epochs, it is shown that the
average rainfall is higher in all seven rainfall indices during periods of
greater solar activity, at {\it z}-test confidence levels of 95% or greater in
three of them.


title:
The magnetized dusty plasma discharge : negative and positive space
  charge modes

abstract:
  The structure of a discharge across a magnetic field in a dusty plasma is
analysed. The dust macroparticles are negatively charged, but are unmagnetized
because of their high mass. The electrons are highly magnetized, and the ions
have intermediate magnetization. This results in different transport rates of
the different species across the magnetic field. Depending on the size of the
magnetic field, and the relative charge on the different species, the dust
grains can be the dominant current carrier. The space charge clouds near the
electrodes will then be determined by the relative mobility of the different
species. The discharge can operate in one of two modes, a positive space charge
(PSC) mode, characterized by a strong cathode fall, and a negative space charge
(NSC) mode, characterized by a broad anode fall. Features unique to the dust
particles can also play a role in the structure of the discharge, such as the
variable equilibrium charge on the grains, dependent on the local potential and
species temperatures, the effect of gravity on the grain dynamics, and the rate
of charging of the grains. The dust grains can also form an ordered structure,
the dust-plasma crystal. A fluid model of the different species is used to
calculate the structure of the resulting discharge, incorporating the above
effects. The transition from the PSC mode to the NSC mode as the magnetic
field, pressure and dust properties are varied is demonstrated.


title:
Gas temperature effect on the time for onset of particle nucleation in
  argon diluted acetylene plasma

abstract:
  In our work we are focused on study of powder formation in C2H2/Ar plasmas.
In this scope we used a combination of FTIR and mass spectroscopy, which are
the mostly used experimental techniques for plasma powder formation
diagnostics. To test the proposed mechanism for particle nucleation delay we
measured the particle nucleation under different plasma conditions: firstly we
increased the gas temperature and secondly we changed the background gas from
argon to helium.


title:
The influences of the Magnetic Shear on the Improvement of the Quality
  of the Confinement in Plasma of Tokamak

abstract:
  In this paper we have studied the influence of reversed shear on the
improvement of the confinement's quality in the plasma of tokamak and
especially in reducing the anomalous transport. For that, we have used a
special model for the drift wave fields. Comparison between particles
trajectories for normal and reversed shear is carried out in 2 D and 3 D
presentation. Also, the diffusion coefficient of particles for the two cases,
normal and negative shear, is evaluated.


title: A linear theory for control of non-linear stochastic systems

abstract:
  We address the role of noise and the issue of efficient computation in
stochastic optimal control problems. We consider a class of non-linear control
problems that can be formulated as a path integral and where the noise plays
the role of temperature. The path integral displays symmetry breaking and there
exist a critical noise value that separates regimes where optimal control
yields qualitatively different solutions. The path integral can be computed
efficiently by Monte Carlo integration or by Laplace approximation, and can
therefore be used to solve high dimensional stochastic control problems.


title: Few-cycle soliton propagation

abstract:
  Soliton propagation is usually described in the ``slowly varying envelope
approximation'' (SVEA) regime, which is not applicable for ultrashort pulses.
We present theoretical results and numerical simulations for both NLS and
parametric ($\chi^{(2)}$) ultrashort solitons in the ``generalised few-cycle
envelope approximation'' (GFEA) regime, demonstrating their altered
propagation.


title: Vortex knots in light

abstract:
  Optical vortices generically arise when optical beams are combined. Recently,
we reported how several laser beams containing optical vortices could be
combined to form optical vortex loops, links and knots embedded in a light beam
(Leach et al 2004). Here, we describe in detail the experiments in which vortex
loops form these structures. The experimental construction follows a
theoretical model originally proposed by Berry and Dennis, and the beams are
synthesised using a programmable spatial light modulator and imaged using a CCD
camera.


title:
Studies of beam offset due to beam-beam interactions at a warm linear
  collider

abstract:
  At a warm linear collider the short time interval at which bunches will pass
near each other in the interaction region may lead to significant alteration of
the bunches positions. In this paper we quantify the intensity of this effect
and show that it can be addressed by a fast intra-pulse feedback system.


title: The Neutrino Factory and Beta Beam Experiments and Development

abstract:
  The long-term prospects for fully exploring three-flavor mixing in the
neutrino sector depend upon an ongoing and increased investment in the
appropriate accelerator R&D. Two new concepts have been proposed that would
revolutionize neutrino experiments, namely the Neutrino Factory and the Beta
Beam facility. These new facilities would dramatically improve our ability to
test the three-flavor mixing framework, measure \textsl{CP} violation in the
lepton sector, and perhaps determine the neutrino mass hierarchy, and, if
necessary, probe extremely small values of the mixing angle $\theta_{13}$. The
stunning sensitivity that could be achieved with a Neutrino Factory is
described, together with our present understanding of the corresponding
sensitivity that might be achieved with a Beta Beam facility. In the Beta Beam
case, additional study is required to better understand the optimum Beta Beam
energy, and the achievable sensitivity. Neither a Neutrino Factory nor a Beta
Beam facility could be built without significant R&D. An impressive Neutrino
Factory R&D effort has been ongoing in the U.S. and elsewhere over the last few
years and significant progress has been made towards optimizing the design,
developing and testing the required accelerator components, and significantly
reducing the cost. The recent progress is described here.


title:
The Accuracy of IRI in the Description of Development of the Equatorial
  (Appleton) Anomaly

abstract:
  An accuracy of the last version of International Reference Ionosphere
IRI-2001 at low latitudes is tested by a detailed comparison of longitudinal
variations in the equatorial anomaly development following from this model with
the ones given by independent ISS-b satellite data. The critical frequency of
F2-layer was calculated by either CCIR or URSI submodel, both of which are
incorporated into IRI-2001. The main conclusion of our analysis is that the
longitudinal variations given by CCIR are substantially oversmoothed in
comparison with the ISS-b satellite data, and the variations given by URSI are
further smoothed with respect to the CCIR ones. Therefore, further improvements
of model description of the low-latitude F2-layer are desirable.


title: A theoretical and numerical approach to "magic angle" of stone skipping

abstract:
  We investigate oblique impacts of a circular disk and water surface. An
experiment [ Clanet, C., Hersen, F. and Bocquet, L., Nature 427, 29 (2004) ]
revealed that there exists a "magic angle" of 20 [deg.] between a disk face and
water surface which minimize the required speed for ricochet. We perform
3-dimensional simulation of the water impacts using the Smoothed Particle
Hydrodynamics (SPH) and analyze the results with an ordinal differential
equation (ODE) model. Our simulation is in good agreement with the experiment.
The analysis with the ODE model give us a theoretical insight for the ``magic
angle" of stone skipping.


title:
Transition from local to global phase synchrony in small world neural
  network and its possible implications for epilepsy

abstract:
  Temporal correlations in the brain are thought to have very dichotomic roles.
On one hand they are ubiquitously present in the healthy brain and are thought
to underlie feature binding during information processing. On the other hand
large scale synchronization is an underlying mechanism of epileptic seizures.
In this paper we show a possible mechanism of transition to pathological
coherence underlying seizure generation. We show that properties of phase
synchronization in the 2-D lattice of non-identical coupled Hindmarsh-Rose
neurons change radically depending on the connectivity structure. We modify the
connectivity using the small world network paradigm and measure properties of
phase synchronization using previously developed measure based on assessment of
the distributions of relative interspike intervals. We show that the phase
synchronization undergoes a dramatic change as a function of locality of
network connections from local coherence strongly dependent on the distance
between two neurons to global coherence exhibiting stronger phase locking and
spanning the whole network.


title: Lorentz's electromagnetic mass: a clue for unification?

abstract:
  We review in the present article the conjecture of electromagnetic mass by
Lorentz. The philosophical perspectives and historical accounts of this idea
are described, especially, in the light of Einstein's special relativistic
formula {E = mc^2}. It is shown that the Lorentz's electromagnetic mass model
has taken various shapes through its journey and the goal is not yet reached.


title:
Electron cyclotron resonance discharge as a source for hydrogen and
  deuterium ions production

abstract:
  In this report, we describe characteristics of a ring-structure hydrogen
plasma heated in electron cyclotron resonance conditions and confined in a
mirror magnetic trap and discuss the relative efficiency of secondary electrons
and thermoelectrons in negative hydrogen and deuterium ion production. The
obtained data and calculations of the balance equations for possible reactions
demonstrate that the negative ion production is realized in two stages. First,
the hydrogen and deuterium molecules are excited in collisions with the plasma
electrons to high-laying Rydberg or vibrational levels in the plasma volume.
The second stage leads to the negative ion production through the process of
dissociative attachment of low energy electrons. The low energy electrons are
originated due to a bombardment of the plasma electrode by ions of one of the
driven rings and thermoemission from heated tungsten filaments. Experiments
seem to indicate that the negative ion generation occurs predominantly in the
limited volume filled with thermoelectrons. Estimation of the negative ion
generation rate shows that the main channel of and ion production involves the
process of high Rydberg state excitation.


title:
Which gravitomagnetic precession rate will be measured by Gravity Probe
  B?

abstract:
  General relativity predicts a "hyperfine" precession rate for a gyroscope
moving in the gravitomagnetic field of a rotating massive body. The recently
launched Gravity Probe B (GP-B) will test the predicted precession rate of 40.9
milliarc-seconds per year for a set of four gyroscopes in a Polar Earth Orbit
(PEO). It may be possible, however, that the gravitomagnetic field from a
rotating mass behaves in the same way as the magnetic field generated by a
moving charge. In that case the predicted precession rate of a gyroscope will
be zero, since the gyroscopes of GP-B have been shielded against external
magnetic fields. Another possible manifestation of the equivalence of
gravitomagnetic and magnetic field may already have been found. It is the
so-called Wilson Blackett law, approximately describing the magnetic field of
many rotating celestial bodies. In this work a review of the gravitomagnetic
approach is given starting from the Einstein equations. Four gravitomagnetic
equations, analogous to the Maxwell equations, are deduced. The Wilson Blackett
relation follows from these equations, if the gravitomagnetic field is
identified as a common magnetic field. In addition, the precession rate for a
gyroscope in terms of the gravito-magnetic field has been derived, starting
from the principle of general covariance. The gravitomagnetic field may again
be identified as a common magnetic field, or can be evaluated in the standard
way. The future observations from GP-B may discriminate between the alternative
choices.


title:
Polygonal walls and the astronomical alignments of the Acropolis of
  Alatri, Italy: a preliminary investigation

abstract:
  The astronomical orientation of the acropolis of Alatri, Italy, is analyzed.
The results support the idea that this town, with its magnificent polygonal
walls, was constructed well before the Roman expansion.


title:
Exploring Core-to-edge Transport in Aditya Tokamak by Oscillations
  Observed in the edge Radiation

abstract:
  Understanding of the transport in a Tokamak plasma is an important issue.
Various mechanisms have been reported in the literature to relate the core
phenomenon to edge phenomenon. Sawtooth and Mirnov oscillations caused by MHD
instabilities are generally observed in Tokamak discharges. Observation of
these effects in the visible radiation from outer edge may offer a possible
means to understand the transport.Oscillations in the visible radiation from
outer region of the plasma have been observed during recent Aditya discharges.
Percentage modulation of these oscillations vary with the Lines of Sight (LOS)
of the chords and surfaces on which they terminate. This has been found in both
the low frequency (~1 kHz) oscillations that seem to correlate with sawteething
in SXR signals and the higher frequency (~10 kHz) oscillations that correlate
well with Mirnov signals indicative of m/n=2/1 mode rotation. This suggests
that the extent to which the MHD instabilities in the central region of the
plasma column are reflected in the edge radiation depends on the interaction of
the plasma with the surface at the extremity of the LOS. The release of
particle/ energy accompanying the MHD instabilities leads to a large influx of
particles from such surfaces. Cross-bispectral analysis suggests that a mode
(having frequency of ~20 kHz) is also generated due to the interaction of
m/n=1/1 (~10 kHz, seen in SXR) and m/n=2/1 (~10 kHz, seen in Mirnov, Visible &
Microwave Interferometer signals). By possible selection rules, this mode seems
to be a m/n=3/2 mode. This mode is seen in Mirnov, Visible & Interferometer
signals. Behaviour of these oscillations on various LOS and their relation to
SXR&Mirnov signals can lead to an understanding of the transport phenomenon.
These observations and our interpretations will be presented.


title: Multitoroidal configurations as equilibrium flow eigenstates

abstract:
  Equilibrium eigenstates of an axisymmetric magnetically confined plasma with
toroidal flow are investigated by means of exact solutions of the ideal
magnetohydrodynamic equations. The study includes "compressible" flows with
constant temperature, but varying density on magnetic surfaces and
incompressible ones with constant density, but varying temperature thereon. In
both cases eigenfunctions of the form Psi_{nl} = Z_l(z)R_n(R) (l, n=1,2,...)
describe configurations with lxn magnetic axes. By varying the flow parameters
a change in magnetic topology is possible. In addition, the effects of the flow
and the aspect ratio on the Shafranov shift are evaluated along with the
variations of density and temperature on magnetic surfaces.


title:
Modulation of harmonic emission spectra from intense laser-plasma
  interaction

abstract:
  We report results from a series of PIC simulations carried out to investigate
the interaction of intense laser light with overdense plasma and in particular,
aspects of the harmonic emission spectrum generated in these interactions.
Recent observations of emission in this range by Watts et al. (2002) show
emission above the 20th harmonic extending to the 37th with conversion
efficiencies of order 10^-6 with this spectrum showing distinct, if variable,
modulation of between two and four harmonics. This spectral feature proved
highly sensitive to the incident intensity, with more pronounced modulation at
higher intensities. These authors also reported results from a set of model PIC
simulations which showed a modulated emission spectrum across the entire
harmonic range, but with a wider modulation bandwidth. In the results to be
presented we report on features of the emission spectrum across a wide
parameter range and its dependence on the detailed structure of the plasma
density profile. While we do see evidence of a modulated spectrum, this appears
to be sensitive not only to the incident intensity but to the plasma density
profile. In addition plasma emission present further complicates the harmonic
emission spectrum. Our results lead us to conclude that attempts to interpret
modulation in emission spectra in terms of one particular theoretical model and
from this to infer the dynamics of the critical surface may be misguided.


title: Inference of Schr\"odinger's Equation from Classical-Mechanical Solution

abstract:
  We set up the classical wave equation for a particle formed of an oscillatory
zero-rest-mass charge together with its resulting electromagnetic waves,
traveling in a potential field $V$ in a susceptible vacuum. The waves are
Doppler-displaced upon the source motion, and superpose into a total,
traveling- and in turn a standing- beat wave, or de Broglie phase wave,
described by a corresponding total classical wave equation. By
back-substitution of the explicitly known total, standing beat wave function
and upon appropriate reductions at classic-velocity limit, we separate out from
the total a component wave equation describing the kinetic motion of particle,
which is equivalent to the Schr\"odinger equation. The Schr\"odinger wave
function follows to be the envelope function of the standing beat wave at
classic-velocity limit.

categories: physics.class-ph cond-mat.mes-hall hep-th quant-ph


title: The D0 Run II Trigger System

abstract:
  I present the current status of the D0 trigger system in Run II at the
Tevatron.


title:
The Certification of ATLAS Thin Gap Chambers Produced in Israel and
  China

abstract:
  Thin gap chambers (TGCs) are used for the muon trigger system in the forward
region of the LHC experiment ATLAS. A TGC consists of a plane of closely spaced
wires maintained at positive high voltage, sandwiched between resistive
grounded cathode planes with an anode wire to cathode plane gap distance
smaller than the wire-to-wire spacing. The TGCs are expected to provide a
trigger signal within 25 ns of the bunch spacing of the LHC accelerator, with
an efficiency exceeding 95%, while exposed to an effective photon and neutron
background ranging from 30 to 500 Hz/cm2. About 2,500 out of the 3,600 ATLAS
TGCs are being produced at the Weizmann institute in Israel, and in Shandong
University in China. Once installed in the ATLAS detector the TGCs will be
inaccessible. A vigorous production quality control program is therefore
implemented at the production sites. Furthermore, after chamber completion, a
thorough program of quality assurance is implemented to ensure the efficient
performance of the chambers during more than ten years of operation in the LHC
high rate environment. This program consists of a detailed mapping of the
detectors response using cosmic rays, as well as checking the chambers behavior
using a high rate radiation source. An aging test performed on five chambers in
a serial gas connection is presented. Finally the results of the chambers
certification tests performed at CERN before the installation in ATLAS are
described.


title: Electrodynamics on the Moebius Strip

abstract:
  In this diploma work electrostatics and -dynamics of two dimensional
structures are examined. Mathematica is used for visualisation and packages for
Mathematica have been programmed which use subroutines written in C to improve
numerical calculations.
  The well known Moebius Strip is used as an example structure throughout the
work.


title: Random walk and balancing

abstract:
  Presents a minireview of topics concerned with balancing in quiet (bipedal)
standing, and balancing of a stick. In the focus is the apparent stochastic
nature of the swaying of the human inverted pendulum.


title:
A new set of Monte Carlo moves for lattice random-walk models of biased
  diffusion

abstract:
  We recently demonstrated that standard fixed-time lattice random-walk models
cannot be modified to properly represent biased diffusion processes in more
than two dimensions. The origin of this fundamental limitation appears to be
the fact that traditional Monte Carlo moves do not allow for simultaneous jumps
along each spatial direction. We thus propose a new algorithm to transform
biased diffusion problems into lattice random walks such that we recover the
proper dynamics for any number of spatial dimensions and for arbitrary values
of the external field. Using a hypercubic lattice, we redefine the basic Monte
Carlo moves, including the transition probabilities and the corresponding time
durations, in order to allow for simultaneous jumps along all Cartesian axes.
We show that our new algorithm can be used both with computer simulations and
with exact numerical methods to obtain the mean velocity and the diffusion
coefficient of point-like particles in any dimensions and in the presence of
obstacles.


title:
Exact Solutions of the Equations of Motion of Liquid Helium with a
  Charged Free Surface

abstract:
  The dynamics of the development of instability of the free surface of liquid
helium, which is charged by electrons localized above it, is studied. It is
shown that, if the charge completely screens the electric field above the
surface and its magnitude is much larger then the instability threshold, the
asymptotic behavior of the system can be described by the well-known 3D
Laplacian growth equations. The integrability of these equations in 2D geometry
makes it possible to described the evolution of the surface up to the formation
of singularities, viz., cuspidal point at which the electric field strength,
the velocity of the liquid, and the curvature of its surface assume infinitely
large values. The exact solutions obtained for the problem of the
electrocapillary wave profile at the boundary of liquid helium indicate the
tendency to a charge in the surface topology as a result of formation of
charged bubbles.


title: Estimation of time delay by coherence analysis

abstract:
  Using coherence analysis (which is an extensively used method to study the
correlations in frequency domain, between two simultaneously measured signals)
we estimate the time delay between two signals. This method is suitable for
time delay estimation of narrow band coherence signals for which the
conventional methods cannot be reliably applied. We show by analysing coupled
R\"ossler attractors with a known delay, that the method yields satisfactory
results. Then, we apply this method to human pathologic tremor. The delay
between simultaneously measured traces of Electroencephalogram (EEG) and
Electromyogram (EMG) data of subjects with essential hand tremor is calculated.
We find that there is a delay of 11-27 milli-seconds ($ms$) between the tremor
correlated parts (cortex) of the brain (EEG) and the trembling hand (EMG) which
is in agreement with the experimentally observed delay value of 15 $ms$ for the
cortico-muscular conduction time. By surrogate analysis we calculate error-bars
of the estimated delay.


title:
Doppler effects in a left-handed material: a first-principle theoretical
  study

abstract:
  The Doppler effects for the reflected wave from a moving media are
systemically analyzed in this paper. The theoretical formula for the Doppler
shift in the left-handed material, which is described by Drude's dispersion
model, is presented. This formula is examined by first-principles numerical
experiments, which are in agreement with the theoretical results.


title:
Simulation of Heavily Irradiated Silicon Pixel Sensors and Comparison
  with Test Beam Measurements

abstract:
  Charge collection measurements performed on heavily irradiated p-spray DOFZ
pixel sensors with a grazing angle hadron beam provide a sensitive
determination of the electric field within the detectors. The data are compared
with a complete charge transport simulation of the sensor which includes signal
trapping and charge induction effects. A linearly varying electric field based
upon the standard picture of a constant type-inverted effective doping density
is inconsistent with the data. A two-trap double junction model implemented in
the ISE TCAD software can be tuned to produce a doubly-peaked electric field
which describes the data reasonably well. The modeled field differs somewhat
from previous determinations based upon the transient current technique. The
model can also account for the level of charge trapping observed in the data.


title:
A new parallel strategy for two-dimensional incompressible flow
  simulations using pseudo-spectral methods

abstract:
  A novel parallel technique for Fourier-Galerkin pseudo-spectral methods with
applications to two-dimensional Navier-Stokes equations and inviscid Boussinesq
approximation equations is presented. It takes the advantage of the programming
structure of the phase-shift de-aliased scheme for pseudo-spectral codes, and
combines the task-distribution strategy [Yin, Clercx and Montgomery, Comput.
Fluids, 33, 509 (2004)] and parallelized Fast Fourier Transform scheme. The
performances of the resulting MPI Fortran90 codes with the new procedure on SGI
3800 are reported. For fixed resolution of the same problem, the peak speed of
the new scheme can be twice as fast as the old parallel methods. The
parallelized codes are used to solve some challenging numerical problems
governed by the Navier-Stokes equations and the Boussinesq equations. Two
interesting physical problems, namely, the double-valued $\omega$-$\psi $
structure in two-dimensional decaying turbulence and the collapse of the bubble
cap in the Boussinesq simulation, are solved by using the proposed parallel
algorithms.

categories: physics.comp-ph physics.flu-dyn physics.geo-ph physics.plasm-ph


title:
Hot-border effects, ordering, and avalanches in planar arrays of
  superheated superconducting granules

abstract:
  We present results of simulations of transitions in planar arrays of
superheated superconducting granules (PASS) immersed in an external magnetic
field parallel to the system. Analysis of the behaviour of the system when the
external field is slowly increased from zero shows the existence of an interval
of external fields for which no transitions are produced. This gap is found to
be a consequence of ordering induced by transitions. However, this ordering is
different for diluted and for concentrated systems. Avalanches of different
sizes with distributions depending on concentration are observed.


title:
The third order effect for the electromagnetic wave in the frame moving
  transverse to the wave

abstract:
  It is considered the electromagnetic wave in the frame moving transverse to
the wave. Due to the velocity of the frame with respect to a preferred
reference frame the oscillations of phase arise. The oscillations of phase
yield the third order effect which can be seen in the Michelson-Morley
experiment. The effect due to the velocity of the earth with respect to CMB is
in agreement with the anisotropy determined in the Michelson-Morley experiment.


title:
The aerogel threshold Cherenkov detector for the High Momentum
  Spectrometer in Hall C at Jefferson Lab

abstract:
  We describe a new aerogel threshold Cherenkov detector installed in the HMS
spectrometer in Hall C at Jefferson Lab. The Hall C experimental program in
2003 required an improved particle identification system for better
identification of pi/K/P, which was achieved by installing an additional
threshold Cherenkov counter. Two types of aerogel with n=1.03 and n=1.015 allow
one to reach 10^{-3} proton and 10^{-2} kaon rejection in the 1-5 GeV/c
momentum range with pion detection efficiency better than 99% (97%). The
detector response shows no significant position dependence due to a diffuse
light collection technique. The diffusion box was equipped with 16 Photonis
XP4572 PMT's. The mean number of photoelectrons in saturation was ~16 and ~8,
respectively. Moderate particle identification is feasible near threshold.


title: Polarized Proton and Deuteron Beams at COSY

abstract:
  Aim of this paper is to present a brief and basic introduction to polarized
beams and the behaviour of a particle's spin in an electromagnetic field. It is
not intended to give a complete presentation of the spin dynamic theory.
Instead the most importa nt features are given without proof and details not
absolutely necessary are left out. Spin depolarizing mechanisms are discussed
and the cures against depolarizing especially during acceleration as utilized
at COSY are outlined. A list of references is given at the end to help the
reader to find more deep details on spin dynamic theory [1].


title:
A Theoretical Framework for Physics Education Research: Modeling Student
  Thinking

abstract:
  Education is a goal-oriented field. But if we want to treat education
scientifically so we can accumulate, evaluate, and refine what we learn, then
we must develop a theoretical framework that is strongly rooted in objective
observations and through which different theoretical models of student thinking
can be compared. Much that is known in the behavioral sciences is robust and
observationally based. In this paper, I draw from a variety of fields ranging
from neuroscience to sociolinguistics to propose an over-arching theoretical
framework that allows us to both make sense of what we see in the classroom and
to compare a variety of specific theoretical approaches. My synthesis is
organized around an analysis of the individual's cognition and how it interacts
with the environment. This leads to a two level system, a knowledge-structure
level where associational patterns dominate, and a control-structure level
where one can describe expectations and epistemology. For each level, I sketch
some plausible starting models for student thinking and learning in physics and
give examples of how a theoretical orientation can affect instruction and
research.


title:
Markov Chains of Infinite Order and Asymptotic Satisfaction of Balance:
  Application to the Adaptive Integration Method

abstract:
  Adaptive Monte Carlo methods can be viewed as implementations of Markov
chains with infinite memory. We derive a general condition for the convergence
of a Monte Carlo method whose history dependence is contained within the
simulated density distribution. In convergent cases, our result implies that
the balance condition need only be satisfied asymptotically. As an example, we
show that the adaptive integration method converges.


title:
Observations of three slow glitches in the spin rate of the pulsar
  B1822-09

abstract:
  Three slow glitches in the rotation rate of the pulsar B1822-09 were revealed
over the 1995-2004 interval. The slow glitches observed are characterized by a
gradual increase in the rotation frequency with a long timescale of several
months, accompanied by a rapid decrease in the magnitude of the frequency first
derivative by 1-2 per cent of the initial value and subsequent exponential
increase back to its initial value on the same timescale. The cumulative
fractional increase in the pulsar rotation rate for the three glitches amounts
to Delta_nu/nu ~ 7 10^{-8}.


title: Marginal Confinement in Tokamaks by Inductive Electric Field

abstract:
  Here diffusion and Ware pinch are analyzed as opposed effects for plasma
confinement, when instabilities are not considered. In this work it is studied
the equilibrium inductive electric field where both effects annul each other in
the sense that the average normal velocity is zero, that is, marginal velocity
confinement is reached. The critical electric field defined in that way is
studied for different values of elliptic elongation, Shafranov shift and
triangularity. A short complementary analysis is also performed of the
variation of the poloidal magnetic field along a magnetic line.
Magnetohydrodynamic transport theory in the collisional regime is used as in
recent publications. Axisymmetric and up-down symmetry are assumed


title:
Formation mechanism of the atmospheric ball lightning using the triple
  Beltrami equation

abstract:
  Ball lightning, also known as fire ball, is a luminous globe which occurs in
the course of a thunderstorm. Taking as model of fire ball, the two fluid
plasma consisting of electrons and one species ions, and considering that the
plasma flow is a finite quantity, we can derive the equation of relaxed energy
state, maintaining the helicity constant, in the form of triple
Beltramiequations for the magnetic field: s curl x curl x curl x B + p curl x
curl x B +q curl xB +r B = 0. Where B is the magnetic field s, p, q, and r are
constants to be determined through boundary conditions. This equation is
coupled with an equation which describes the hydrodynamic vortex. The problem
of the formation of an isolated luminous mass in the sky and the moderate
persistence of the resulting form combined with observations of ball lightning
describing hollow globes, surface coronas and rapid rotation led to theories
depicting ball lightning as a vortex. We explore the solutions of this equation
using the method of Chandrasekhar-Kendall eigenfunctions and appropriate
boundary conditions similar, but more extensive, to the description given by
Shukla, Dasgupta and Sakanaka. We will show solutions which might explain the
fire ball configurations.Supported by FAPESP-Fundacao de Amparo a Pesquisa do
Estado de Sao Paulo.


title: On the invariant formulation of fluid mechanics

abstract:
  It can be observed that the differential operators of fluid mechanics can be
defined in terms of the complete derivative on the finite - dimensional affine
space. It follows from the fact that all norms on the finite - dimensional
vector space are equivalent and from the definition of the complete derivative
on the normed affine spaces (see: L.Schwartz, Analyse Mathematique, Hermann,
1967). In particular, it is shown that the "substantial derivative" of the
standard formulation is a directional derivative along the "non - relativistic
four - velocity".


title:
Anomalous absorption of light by a nanoparticle and bistability in the
  presence of resonant fluorescent atom

abstract:
  Absorption of light by a nanoparticle in the presence of resonant atom and
fluorescence of the latter are theoretically investigated. It is shown, that
absorption of light by a nanoparticle can be increased by several orders
because of presence of atom. It is established, that optical bistability in
such system is possible.


title: Design considerations for future DAFNE upgrade

abstract:
  The Frascati F-Factory DAFNE has been delivering luminosity to the KLOE, DEAR
and FINUDA experiments since year 2000. Since April 2004 the KLOE run has been
resumed and recently peak luminosity of 1.0x1032 cm-2s-1 and integrated
luminosity of 6.2 pb-1/day have been achieved. The scientific program of the
three high-energy experiments sharing DAFNE operation will be completed
approximately by the end of year 2006. A scientific program for DAFNE beyond
that date has not been defined yet and it is matter of discussion in the
high-energy physics and accelerator physics communities. In this paper we
present some future scenarios for DAFNE, discussing the expected ultimate
performances of the machine as it is now and addressing the design for an
energy and/or luminosity upgrade. The options presented in the following are
not exhaustive and they are intended to give a glance of what is doable using
the existing infrastructures.


title: From normal state to magnetic storms in terms of fractal dynamics

abstract:
  We show that distinctive alterations in scaling parameters of Dst index time
series occur as a strong magnetic storm approaches. These alterations reveal a
gradual reduction of complexity as the catastrophic event approaches. The
increase of the susceptibility coupled with the transition from anti-persistent
to persistent behavior may indicate that the onset of a severe magnetic storm
is imminent. The preparation of a major magnetic storm could be studied in
terms of "Intermittent Criticality". The analysis also suggests that the
continuous scale invariance is partially broken into a discrete scale
invariance symmetry.


title:
Probing Dynamics at Interfaces: Molecular Motions in Lipid Bilayers
  studied by Neutron Backscattering

abstract:
  Lipid membranes in a physiological context cannot be understood without
taking into account their mobile environment. Here, we report on a high
energy-resolution neutron backscattering study to investigate slow motions on
nanosecond time scales in highly oriented solid supported phospholipid bilayers
of the model system DMPC -d54 (deuterated
1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine). This technique allows
discriminating the Q-dependent onset of mobility and provides a benchmark test
regarding the feasibility of dynamical neutron scattering investigations on
these sample systems. Apart from freezing of the lipid acyl-chains, we could
observe a second freezing temperature that we attribute to the hydration water
in between the membrane stacks. The freezing is lowered several degrees as
compared to (heavy) bulk water.


title:
rkdg and Hybrid rkdg+hweno Schemes for Divergence-Free
  Magnetohydrodynamics Part I

abstract:
  Balsara (2001) showed the importance of divergence-free reconstruction in
adaptive mesh refinement problems for magnetohydrodynamics (MHD) and the
importance of the same for designing robust second order schemes for MHD was
shown in Balsara (2004). In this paper we show that the reconstruction of
divergence-free vector fields can be carried out with better than second order
accuracy. As a result, we design divergence-free RKDG and hybrid RKDG+HWENO
schemes for MHD that have accuracies that are better than second order.
Accuracy analysis is carried out and it is shown that the schemes meet their
design accuracy for smooth problems. Stringent one-dimensional tests are also
presented showing that the schemes perform well on those tests.


title:
A Sub-Cell Based Indicator for Troubled Zones in RKDG Schemes and a
  Novel Class of Hybrid RKDG+HWENO Schemes

abstract:
  Runge Kutta Discontinuous Galerkin (RKDG) schemes can provide highly accurate
solutions for a large class of important scientific problems. Using them for
problems with shocks and other discontinuities requires that one has a strategy
for detecting the presence of these discontinuities. In order to get past
previous limitations in designing a limiter, we realize that the solution in
RKDG schemes can carry meaningful sub-structure within a zone that may not need
to be limited. To make this sub-structure visible, we take a sub-cell approach
to detecting zones with discontinuities, known as troubled zones. A
monotonicity preserving (MP) strategy is applied to distinguish between
meaningful sub-structure and shocks. The strategy does not indiscriminately
clip extrema and is, nevertheless, scale-free and problem-independent. The
moments of the troubled zones is corrected using a weighted essentially
non-oscillatory (WENO) or Hermite WENO (HWENO) approach. In the course of doing
this work it was also realized that the most significant variation in the
solution is contained in the solution variables and their first moments. Thus
it is shown that the additional moments can be reconstructed using the
variables and their first moments, resulting in a very substantial savings in
computer memory and without any loss in order of accuracy. We call such schemes
hybrid RKDG+HWENO schemes. Explicit, easy to implement formulae have been
catalogued for third and fourth order of spatial accuracy. Several stringent
test problems have also been presented.


title:
Understanding the temperature and the chemical potential using computer
  simulations

abstract:
  Several Monte Carlo algorithms and applications that are useful for
understanding the concepts of temperature and chemical potential are discussed.
We then introduce a generalization of the demon algorithm that measures the
chemical potential and is suitable for simulating systems with variable
particle number.


title:
Propagation of ultrashort electromagnetic wave packets in free space
  beyond the paraxial and slowly-varying-envelope approximations : a
  time-domain approach

abstract:
  A time-domain approach is proposed for the propagation of ultrashort electro-
magnetic wave packets beyond the paraxial and the slowly-varying-envelope
approximations. An analytical method based on perturbation theory is used to
solve the wave equation in free space without resorting to Fourier trans-
forms. An exact solution is obtained in terms of successive temporal and
spatial derivatives of a monochromatic paraxial beam. The special case of a
radially polarized transverse magnetic wave packet is discussed.


title: NMR detection with an atomic magnetometer

abstract:
  We demonstrate detection of NMR signals using a non-cryogenic atomic
magnetometer and describe several novel applications of this technique. A water
free induction decay (FID) signal in a 0.5 $\mu$T field is detected using a
spin-exchange-relaxation-free K magnetometer and the possibility of using a
multi-channel magnetometer for 3-D MRI requiring only a single FID signal is
described. We also demonstrate detection of less than $10^{13}$ $^{129}$Xe
atoms whose NMR signal is enhanced by a factor of 540 due to Fermi-contact
interaction with K atoms. This technique allows detection of less than $10^{9}$
$^{129}$Xe spins in a flowing system suitable for remote NMR applications.


title: Recovery of graded index profile by cubic spline function

abstract:
  We present in this paper a method to recover the refractive index profile of
graded waveguide from the effective indices by cubic spline interpolation
function. It is proved by numerical analysis of several typical index
distributions that the refractive index profile can be reconstructed closely to
its exact profile with the presented interpolation model. This method can
reliably retrieve index profile of both more-mode (more than 4 guiding mode)
and fewer-mode (2-4) waveguides.


title:
Explicit expression for the photon number emission in synchrotron
  radiation

abstract:
  An explicit and remarkably simple one-dimensional integral expression is
derived for the mean number $<N>$ of photons emitted per revolution in
synchrotron radiation. The familiar high-energy expression
$5\pi\alpha/\sqrt{3(1-\beta^2)}$, printed repeatedly in the literature, is
found to be inaccurate and only truly asymptotic with relative errors of 160%,
82% for $\beta=0.8$, 0.9, respectively. A new improved high-energy expression
for $<N>$ is given.


title:
The Proof that the Standard Transformations of E and B are not the
  Lorentz Transformations. Application to Motional EMF

abstract:
  In this paper it is proved by using the Clifford algebra formalism that the
standard transformations (ST) of the three-dimensional (3D) vectors of the
electric and magnetic fields E and B are not the Lorentz transformations (LT)
of well-defined quantities from the 4D spacetime. This difference between the
ST and the LT is obtained regardless of the used algebraic objects (1-vectors
or bivectors) for the representation of the electric and magnetic fields in the
usual observer dependent decompositions of F. The LT correctly transform the
whole 4D quantity, e.g., E_{f}=F\cdot \gamma_{0}, whereas the ST are the result
of the application of the LT only to the part of E_{f}, i.e., to F, but leaving
gamma_{0} unchanged. The new decompositions of F in terms of 4D quantities that
are defined without reference frames, i.e., the absolute quantities, are
introduced and discussed. It is shown that the LT of the 4D quantities
representing electric and magnetic fields correctly describe the motional
electromotive force (emf) for all relatively moving inertial observers, whereas
it is not the case with the ST of the 3D E and B.


title:
Research on pinches driven by SPPED 2 generator : hard X-ray and neutron
  emission in plasma focus configuration

abstract:
  SPEED2 is a generator based on Marx technology and was designed in the
University of Dusseldorf. SPEED2 consists on 40 +/- Marx modules connected in
parallel (4.1 mF equivalent Marx generator capacity, 300 kV, 4 MA in short
circuit, 187 kJ, 400 ns rise time, dI/dt~1013 A/s). Currently the SPEED2 is
operating at the Comision Chilena de Energia Nuclear, CCHEN, Chile, being the
most powerful and energetic device for dense transient plasma in the Southern
Hemisphere. Most of the previous works developed in SPEED2 at Dusseldorf were
done in a plasma focus configuration for soft X-ray emission and the neutron
emission from SPEED2 was not completely studied. The research program at CCHEN
considers experiments in different pinch configurations (plasma focus, gas
puffed plasma focus, gas embedded Z-pinch, wire arrays) at current of hundred
of kiloamperes to mega-amperes, using the SPEED2 generator. The Chilean
operation has begun implementing and developing diagnostics in a conventional
plasma focus configuration operating in deuterium in order to characterize the
neutron emission and the hard X-ray production. Silver activation counters,
plastics CR39 and scintillator-photomultiplier detectors are used to
characterize the neutron emission. Images of metallic plates with different
thickness are obtained on commercial radiographic film, Agfa Curix ST-G2, in
order to characterize an effective energy of the hard X-ray outside of the
discharge .


title: Higher-order effective Hamiltonian for light atomic systems

abstract:
  We present the derivation of the effective higher-order Hamiltonian, which
gives $m \alpha^6$ contribution to energy levels of an arbitrary light atom.
The derivation is based on the Foldy-Wouthuysen transformation of the
one-particle Dirac Hamiltonian followed by perturbative expansion of the many
particle Green function. The obtained results can be used for the high
precision calculation of relativistic effects in atomic systems.


title:
Spiral Phyllotaxis Pattern in an Animal Cell: A Fluid- Driven Mechanism
  for Red Cell Echinocytosis and Programmed Cell Death

abstract:
  This paper demonstrates that the pattern of lipid spiculesthat emerge on the
surface of red blood cells in the classic 'Discocyte to Echinocyte' shape
change is a generative spiral, and presents a qualitative, fluid- driven
mechanism for their production, compatible with the work of Douady and Couder.
Implications for the dynamics of cell growth, plant cell phyllotaxy, programmed
cell death and gravity sensitivity are explained in terms of a new qualitative
model of cellular fluid dynamics.


title:
A continuum of Hamiltonian structures for the two-dimensional isotropic
  harmonic oscillator

abstract:
  We show the existence of a continuum of Hamiltonian structures for the
two-dimensional isotropic harmonic oscillator. In particular, a continuum of
Hamiltonian structures having noncommutative coordinates is presented. A study
of the symmetries of these structures is performed and their physical
plausibility is discussed.


title:
Development of submillimeter wave source Gyrotron FU series for plasma
  diagnostics

abstract:
  Our gyrotrons developed in Fukui University, Research Center for Development
of Far Infrared Region (FIR FU) are high frequency, medium power gyrotrons as
millimeter to submillimeter wave radiation sources for application to new
far-infrared technologies including plasma diagnostics. We have already
developed Gyrotron FU Series which consists of 8 gyrotrons. The gyrotron series
has achieved frequency tuneability in wide range (from 38 GHz to 889 GHz). The
highest frequency is corresponding to a wavelength of 337 micrometers. This is
a current record for high frequency operation of gyrotron. Recently, we have
developed a high harmonic gyrotron with an axis-encircling electron beam and a
THz gyrotron with a pulse magnet. In this presentation, the present status of
Gyrotron FU Series is described.


title: The higher-order C_n dispersion coefficients for hydrogen

abstract:
  The complete set of 2nd, 3rd and 4th order van der Waals coefficients, C_n up
to n=32 for the H(1s)-H(1s) dimer are computed using pseudo-states to evaluate
the appropriate sum rules. A study of the convergence pattern for n<=16
indicates that all the C_n (n<=16) coefficients are accurate to 13 significant
digits. The relative size of the 4th-order C^4_n to the 2nd-order C^2_n
coefficients is seen to increase as n increases and at n=32 the 4th-order term
is actually larger.


title: Power loss in open cavity diodes and a modified Child Langmuir Law

abstract:
  Diodes used in most high power devices are inherently open. It is shown that
under such circumstances, there is a loss of electromagnetic radiation leading
to a lower critical current as compared to closed diodes. The power loss can be
incorporated in the standard Child-Langmuir framework by introducing an
effective potential. The modified Child-Langmuir law can be used to predict the
maximum power loss for a given plate separation and potential difference as
well as the maximum transmitted current for this power loss. The effectiveness
of the theory is tested numerically.


title: The higher order C_n dispersion coefficients for the alkali atoms

abstract:
  The van der Waals coefficients, from C_11 through to C_16 resulting from 2nd,
3rd and 4th order perturbation theory are estimated for the alkali (Li, Na, K
and Rb) atoms. The dispersion coefficients are also computed for all possible
combinations of the alkali atoms and hydrogen. The parameters are determined
from sum-rules after diagonalizing the fixed core Hamiltonian in a large basis.
Comparisons of the radial dependence of the C_n/r^n potentials give guidance as
to the radial regions in which the various higher-order terms can be neglected.
It is seen that including terms up to C_10/r^10 results in a dispersion
interaction that is accurate to better than 1 percent whenever the
inter-nuclear spacing is larger than 20 a_0. This level of accuracy is mainly
achieved due to the fortuitous cancellation between the repulsive (C_11, C_13,
C_15) and attractive (C_12, C_14, C_16) dispersion forces.


title:
Generalization of Child-Langmuir Law for Non-Zero Injection Velocities
  in a Planar Diode

abstract:
  The Child-Langmuir law relates the voltage applied across a planar diode to
the saturation value J_CL of current density that can be transmitted through it
in case the injection velocity of electrons into the diode is zero. The
Child-Langmuir current density J_CL is, at the same time, (i) the maximum
current density that can be transmitted through a planar diode, (ii) the
current density below which the flow is steady and unidirectional in the long
time limit and (iii) the average transmitted current density for {\em any}
value of injected current density above J_CL. Existing generalizations of
Child-Langmuir law to non-zero velocities of injection are based on the
characteristics (i) and (ii) of J_CL. This paper generalizes the law to
non-zero velocities of injection based on the characteristic (iii) by deriving
an analytical expression for the saturation value of current density. The
analytical expression for the saturation current density is found to be well
supported by numerical computations. A reason behind preferring the saturation
property of the Child-Langmuir current density as the basis for its
generalization is the importance of that property in numerical simulations of
high current diode devices.


title:
Transverse excitations of ultracold matter waves upon propagation past
  abrupt waveguide changes

abstract:
  The propagation of ultracold atomic gases through abruptly changing waveguide
potentials is examined in the limit of non-interacting atoms. Time-independent
scattering calculations of microstructured waveguides with discontinuous
changes in the transverse harmonic binding potentials are used to mimic
waveguide perturbations and imperfections. Three basic configurations are
examined: step-like, barrier-like and well-like with waves incident in the
ground mode. At low energies, the spectra rapidly depart from single-moded,
with significant transmission and reflection of excited modes. The high-energy
limit sees 100 percent transmission, with the distribution of the transmitted
modes determined simply by the overlap of the mode wave functions and
interference.


title:
The effects of induced scattering of Alfven waves for the solar wind
  acceleratio

abstract:
  The analysis of energy balance of coronal holes gives that to accelerate the
fast solar wind streams the energy flux of the order of 800 erg/cm$^2$ s is
needed. Axford and McKenzie suggested that the energy source, necessary to
accelerate fast solar wind, is in the regions of strong magnetic field that
define the boundaries of chromospheric supergranules. If the magnetic field is
not strictly unipolar in these regions, the necessary energy is released in the
processes of impulsive reconnection events. For the plasma parameters
appropriate for the coronal base such processes of impulsive reconnection are
accompanied by the generation of Alfven and fast magnetosonic waves with the
period of the order of 1 s. On the basis of kinetic equation the model for the
evolution of Alfven waves in solar wind is suggested. The induced scattering of
these waves by plasma ions is considered as the dominant mechanism of
dissipation of Alfven waves. The description of the evolution of the wave
spectra in the process in the processes of their propagation till the distance
of 187 solar radii was found.


title:
Plasma scattering measurement using a submillimeter wave gyrotron as a
  radiation source

abstract:
  Plasma scattering measurement is effective technique to observe low frequency
density fluctuations excited in plasma. The spatial and wave number resolutions
and the S/N ratio of measurement depend on the wavelength range, the size and
the intensity of a probe beam. A well-collimated, submillimeter wave beam is
suitable for improving the spatial and wave number resolutions. Application of
high frequency gyrotron is effective in improving the S/N ratio of the
measurement because of its capacity to deliver high power. Unlike the molecular
vapor lasers, the gyrotrons generate diverging beam of radiation with TEmn mode
structure. It is therefore necessary to convert the output radiation into a
Gaussian beam. A quasi-optical antenna is a suitable element for the conversion
system under consideration since it is applicable to several TE0n and TE1n
modes. In order to apply the gyrotron to plasma scattering measurement, we have
stabilized the output (P=110W, f=354GHz) of gyrotron up to the level (DP/P<1 %,
Df<10 kHz). The gyrotron output can be stabilized by decreasing the fluctuation
of the cathode potential.


title: Joint Probability Distributions for a Class of Non-Markovian Processes

abstract:
  We consider joint probability distributions for the class of coupled Langevin
equations introduced by Fogedby [H.C. Fogedby, Phys. Rev. E 50, 1657 (1994)].
We generalize well-known results for the single time probability distributions
to the case of N-time joint probability distributions. It is shown that these
probability distribution functions can be obtained by an integral transform
from distributions of a Markovian process. The integral kernel obeys a partial
differential equation with fractional time derivatives reflecting the
non-Markovian character of the process.


title: Transonic instabilities in accretion disks

abstract:
  In two previous publications$^{1,2}$, we have demonstrated that stationary
rotation of magnetized plasma about a compact central object permits an
enormous number of different MHD instabilities, with the well-known
magneto-rotational instability as just one of them. We here concentrate on the
new instabilities found that are driven by transonic transitions of the
poloidal flow. A particularly promising class of instabilities, from the point
of view of MHD turbulence in accretion disks, is the class of {\em trans-slow
Alfven continuum modes}, that occur when the poloidal flow exceeds a critical
value of the slow magnetosonic speed. When this happens, virtually every
magnetic/flow surface of the disk becomes unstable with respect to highly
localized modes of the continuous spectrum. The mode structures rotate, in
turn, about the rotating disk. These structure lock and become explosively
unstable when the mass of the central object is increased beyond a certain
critical value. Their growth rates then become huge, of the order of the Alfven
transit time. These instabilities appear to have all requisite properties to
facilitate accretion flows across magnetic surfaces and jet formation.[1] R.
Keppens, F. Casse, J.P. Goedbloed, "Waves and instabilities in accretion disks:
Magnetohydrodynamic spectroscopic analysis", Astrophys. J. {\bf 569},
L121--L126 (2002).[2] J.P. Goedbloed, A.J.C. Belien, B. van der Holst, R.
Keppens, "Unstable continuous spectra of transonic axisymmetric plasmas", Phys.
Plasmas {\bf 11}, 28--54 (2004).


title:
New applications of Equinox code for real-time plasma equilibrium and
  profile reconstruction for tokamaks

abstract:
  Recent development of real-time equilibrium code Equinox [1] using a
fixed-point algorithm [2] allow major plasma magnetic parameters to be
identified in real-time, using rigorous analytical method. The code relies on
the boundary flux code providing flux values on the first wall of vacuum
vessel. By means of least-square minimization of differences between magnetic
field obtained from previous solution and the next measurements the code
identifies the source term of the non-linear Grad-Shafranov equation [3]. The
strict use of analytical equations together with a flexible algorithm offers an
opportunity to include new measurements into stable magnetic equilibrium code
and compare the results directly between several tokamaks while maintaining the
same physical model (i.e. no iron model is necessary inside the equilibrium
code). The successful implementation of this equilibrium code for JET and Tore
Supra have been already published [1], in this paper, we show the preliminary
results of predictive runs of the Equinox code using the ITER geometry.


title:
Measurement of the Charge Collection Efficiency after Heavy Non-Uniform
  Irradiation in BaBar Silicon Detectors

abstract:
  We have investigated the depletion voltage changes, the leakage current
increase and the charge collection efficiency of a silicon microstrip detector
identical to those used in the inner layers of the BaBar Silicon Vertex Tracker
(SVT) after heavy non-uniform irradiation. A full SVT module with the front-end
electronics connected has been irradiated with a 0.9 GeV electron beam up to a
peak fluence of 3.5 x 10^14 e^-/cm^2, well beyond the level causing substrate
type inversion. We irradiated one of the two sensors composing the module with
a non-uniform profile with sigma=1.4 mm that simulates the conditions
encountered in the BaBar experiment by the modules intersecting the horizontal
machine plane. The position dependence of the charge collection properties and
the depletion voltage have been investigated in detail using a 1060 nm LED and
an innovative measuring technique based only on the digital output of the chip.


title:
Particle acceleration through the resonance of high magnetic field and
  high frequency electromagnetic wave

abstract:
  We propose a new particle acceleration mechanism. Electron can be accelerated
to relativistic energy within a few electromagnetic wave cycles through the
mechanism which is named electromagnetic and magnetic field resonance
acceleration (EMRA). We find that the electron acceleration depends not only on
the electromagnetic wave intensity, but also on the ratio between electron
Larmor frequency and electromagnetic wave frequency. As the ratio approaches to
unity, a clear resonance peak is observed, corresponding to the EMRA. Near the
resonance regime, the strong magnetic fields still affect the electron
acceleration dramatically. We derive an approximate analytical solution of the
relativistic electron energy in adiabatic limit, which provides a full
understanding of this phenomenon. In typical parameters of pulsar
magnetospheres, the mechanism allows particles to increase their energies
through the resonance of high magnetic field and high frequency electromagnetic
wave in each electromagnetic wave period. The energy spectra of the accelerated
particles exhibit the synchrotron radiation behavior. These can help to
understand the remaining emission of high energy electron from radio pulsar
within supernova remnant. The other potential application of our theory in fast
ignition scheme of inertial confinement fusion is also discussed.


title:
Additional acceleration and collimation of relativistic electron beams
  by magnetic field resonance at very high intensity laser interaction

abstract:
  In addition to the ponderomotive acceleration of highly relativistic
electrons at interaction of very short and very intense laser pulses, a further
acceleration is derived from the interaction of these electron beams with the
spontaneous magnetic fields of about 100 MG. This additional acceleration is
the result of a laser-magnetic resonance acceleration (LMRA)[1] around the peak
of the azimuthal magnetic field. This causes the electrons to gain energy
within a laser period. Using a Gaussian laser pulse, the LMRA acceleration of
the electrons depends on the laser polarization. Since this is in the resonance
regime, the strong magnetic fields affect the electron acceleration
considerably. The mechanism results in good collimated high energetic electrons
propagating along the center axis of the laser beam as has been observed by
experiments and is reproduced by our numerical simulations.


title: IDeF-X ASIC for Cd(Zn)Te spectro-imaging systems

abstract:
  Joint progresses in Cd(Zn)Te detectors, microelectronics and interconnection
technologies open the way for a new generation of instruments for physics and
astrophysics applications in the energy range from 1 to 1000 keV. Even working
between -20 and 20 degrees Celsius, these instruments will offer high spatial
resolution (pixel size ranging from 300 x 300 square micrometers to few square
millimeters), high spectral response and high detection efficiency. To reach
these goals, reliable, highly integrated, low noise and low power consumption
electronics is mandatory. Our group is currently developing a new ASIC detector
front-end named IDeF-X, for modular spectro-imaging system based on the use of
Cd(Zn)Te detectors. We present here the first version of IDeF-X which consists
in a set of ten low noise charge sensitive preamplifiers (CSA). It has been
processed with the standard AMS 0.35 micrometer CMOS technology. The CSA are
designed to be DC coupled to detectors having a low dark current at room
temperature. The various preamps implemented are optimized for detector
capacitances ranging from 0.5 up to 30 pF.


title: Investigation of Flow Inside an Axial-Flow Pump of GV - IMP Type

abstract:
  The article describes research of fluid flow inside an axial-flow pump that
includes guide vanes, impeller and discharge diffuser. Three impellers with
different hub ratio were researched. The article presents the performance
curves and velocity distributions behind each of the impeller obtained by
computational and experimental ways at six different capacities. The velocity
distributions behind the detached guide vanes of different hub ratio are also
presented. The computational results were obtained using the software tools
CFX-BladeGenPlus and CFX-TASCflow. The experimental performance curves were
obtained using the standard procedure. The experimental velocity distributions
were obtained by probing of the flow. Good correspondence of results, both for
performance curves and velocity distributions, was obtained for most of the
considered cases. As it was demonstrated, the performance curves of the pump
depend essentially on the impeller hub ratio. Velocity distributions behind the
impeller depend strongly on the impeller hub ratio and capacity. Conclusions
concerning these dependencies are drawn.


title:
Numerical simulations studies of the convective instability onset in a
  supercritical fluid

abstract:
  Numerical simulation studies in 2D with the addition of noise are reported
for the convection of a supercritical fluid,3He, in a Rayleigh-Be'nard cell
where the fluid parameters and cell height L are the same as in published
laboratory experiments. The noise addition is to accelerate the instability
onset after starting the heat flow across the fluid, so as to bring simulations
into better agreement with experimental observations. Homogeneous temperature
noise and spatial lateral periodic temperature variations in the top plate were
programmed into the simulations. A speed-up in the instability onset was
obtained, which was most effective through the spatial temperature variations
with a period of 2L, close to the wavelength of a pair of convections rolls.
For a small amplitude of 0.5 microK, this perturbation gave a semiquantitative
agreement with experimental observations. Results for various noise amplitudes
are presented and discussed in relation to predictions by El Khouri and
Carle`s.


title: Multi-Terabyte EIDE Disk Arrays running Linux RAID5

abstract:
  High-energy physics experiments are currently recording large amounts of data
and in a few years will be recording prodigious quantities of data. New methods
must be developed to handle this data and make analysis at universities
possible. Grid Computing is one method; however, the data must be cached at the
various Grid nodes. We examine some storage techniques that exploit recent
developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5)
include both parity and striping. The striping improves access speed. The
parity protects data in the event of a single disk failure, but not in the case
of multiple disk failures.
  We report on tests of dual-processor Linux Software RAID-5 arrays and
Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with
250 and 300 GB disks, for use in offline high-energy physics data analysis. The
price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be
scaled to sizes affordable to small institutions and used when fast random
access at low cost is important.

categories: physics.data-an hep-ex physics.comp-ph physics.ins-det


title:
On a possible new approach for investigating the secular variations of
  the low-degree geopotential coefficients

abstract:
  In this paper we try to suggest a possible novel method to determine some
selected even zonal harmonics J_l of the Earth's geopotential. Time series many
years long of suitably linearly combined residuals of some Keplerian orbital
elements of certain existing geodetic SLR satellites would be examined. A
CHAMP/GRACE-only background reference model should be used for the part of the
geopotential which we are not interested in. The retrieved values for the even
zonal harmonics of interest would be, by construction, independent of each
other and of any post-Newtonian features. The so obtained mini-model could,
subsequently, be used in order to enhance the accuracy and the reliability of
some tests of post-Newtonian gravity, with particular emphasis to the
measurement of the Lense-Thirring effect by means of LAGEOS and LAGEOS II.

categories: physics.geo-ph astro-ph gr-qc physics.space-ph


title: Solar Neutrinos: A Popular Account

abstract:
  This encyclopedia article addresses questions like the following. How does
the Sun shine? Does the neutrino have a mass? Are there weak interactions
beyond those described by the standard model of particle physics?

categories: physics.ed-ph astro-ph hep-ph nucl-ex physics.gen-ph


title:
Streamline topology and dilute particle dynamics in a Karman vortex
  street flow

abstract:
  Three types of streamline topology in a Karman vortex street flow are shown
under the variation of spatial parameters. For the motion of dilute particles
in the K\'arm\'an vortex street flow, there exist a route of bifurcation to a
chaotic orbit and more attractors in a bifurcation diagram for the proportion
of particle density to fluid density. Along with the increase of spatial
parameters in the flow filed, the bifurcation process is suspended, as well as
more and more attractors emerge. In the motion of dilute particles, a drag term
and gravity term dominate and result in the bifurcation phenomenon.


title:
The Robin Hood method - a novel numerical method for electrostatic
  problems based on a non-local charge transfer

abstract:
  We introduce a novel numerical method, named the Robin Hood method, of
solving electrostatic problems. The approach of the method is closest to the
boundary element methods, although significant conceptual differences exist
with respect to this class of methods. The method achieves equipotentiality of
conducting surfaces by iterative non-local charge transfer. For each of the
conducting surfaces non-local charge transfers are performed between surface
elements which differ the most from the targeted equipotentiality of the
surface. The method is tested against analytical solutions and its wide range
of application is demonstrated. The method has appealing technical
characteristics. For the problem with N surface elements, the computational
complexity of the method essentially scales with N^alpha, where alpha < 2, the
required computer memory scales with N, while the error of the potential
decreases exponentially with the number of iterations for many orders of
magnitude of the error, without the presence of the Critical Slowing Down. The
Robin Hood method has a large potential of application in other classical as
well as quantum problems. Some possible applications outside electrostatics are
outlined.


title:
Studies of DC biasing of internal ring on plasma rotation and transport
  in a toroidal geometry

abstract:
  We report results from experiments performed to study how a DC bias with
respect to the plasma potential is affecting the plasma states in the toroidal
geometry of the Blaamann device in Tromso. In the experiments discussed here, a
ring with smaller diameter than the limiter was centered inside the bulk of the
plasma and its bias varied with respect to the plasma potential. In the
electron saturation current regime of the ring, a significant reduction of the
fluctuation levels was observed, and a shear in the poloidal velocity occurred
at the low-field side of the ring. This shear was positioned at the same radial
position as the maximum of the radial transport when the ring was left floating
or biased in the ion saturation current regime. For the latter ring biases, the
poloidal velocities had no shear on the low-field side of the ring. Without the
velocity shear, the radial transport was similar to previous experiments
without ring. With the velocity shear, the radial transport was destroyed. This
plasma state, with very low radial transport and fluctuation levels as well as
plasma densities around 1017 m-3, is believed to provide a suitable plasma for
wave propagation studies in a magnetized plasma with curved magnetic field
lines without end effects.


title: Evidence of crossover phenomena in wind speed data

abstract:
  In this report, a systematic analysis of hourly wind speed data obtained from
three potential wind generation sites (in North Dakota) is analyzed. The power
spectra of the data exhibited a power-law decay characteristic of
$1/f^{\alpha}$ processes with possible long-range correlations. Conventional
analysis using Hurst exponent estimators proved to be inconclusive. Subsequent
analysis using detrended fluctuation analysis (DFA) revealed a crossover in the
scaling exponent ($\alpha$). At short time scales, a scaling exponent of
$\alpha \sim 1.4$ indicated that the data resembled Brownian noise, whereas for
larger time scales the data exhibited long range correlations ($\alpha \sim
0.7$). The scaling exponents obtained were similar across the three locations.
Our findings suggest the possibility of multiple scaling exponents
characteristic of multifractal signals.


title: The Golden Mean and the Physics of Aesthetics

abstract:
  The golden mean, Phi, has been applied in diverse situations in art,
architecture and music, and although some have claimed that it represents a
basic aesthetic proportion, others have argued that it is only one of a large
number of such ratios. We review its early history, especially its relationship
to the Mount Meru of Pingala. We examine the successive divisions of 3, 7, and
22 in Indian music and suggest derivation from variants of Mount Meru. We also
speculate on the neurophysiological basis behind the sense that the golden mean
is a pleasant proportion.


title: Polaritonic materials fabricated and tested with ultrashort-pulse lasers

abstract:
  Using femtosecond laser machining, we have fabricated photonic bandgap
materials that influence propagation of phonon-polaritons in ferroelectric
crystals. Broadband polaritons were generated with impulsive stimulated Raman
scattering (ISRS) using an ultrashort laser pulse, and the spatial and temporal
evolution of the polaritons were imaged as they propagated through the
fabricated structures with polariton real-space imaging. These techniques offer
a new approach to optical materials design.


title:
A high-accuracy optical clock via three-level coherence in neutral
  bosonic $^{88}$Sr

abstract:
  An optical atomic clock scheme is developed that utilizes two lasers to
establish coherent coupling between the $5s^2 \phantom{}^1S_0$ ground state of
$^{88}$Sr and the first excited state, $5s5p \phantom{}^3P_0$. The coupling is
mediated by the broad $5s5p \phantom{}^1P_1$ state, exploiting the phenomenon
of electromagnetically induced transparency. The effective linewidth of the
clock transition can be chosen at will by adjusting the laser intensity. By
trapping the $^{88}$Sr atoms in an optical lattice, long interaction times with
the two lasers are ensured; Doppler and recoil effects are eliminated. Based on
a careful analysis of systematic errors, a clock accuracy of better than
$2\times 10^{-17}$ is expected.


title: Physics the google way

abstract:
  Are we smarter now than Socrates was in his time? Society as a whole
certainly enjoys a higher degree of education, but humans as a species probably
don't get intrinsically smarter with time. Our knowledge base, however,
continues to grow at an unprecedented rate, so how then do we keep up? The
printing press was one of the earliest technological advances that expanded our
memory and made possible our present intellectual capacity. We are now faced
with a new technological advance of the same magnitude--the internet--but how
do we use it effectively? A new tool is available on Google
(http://www.google.com) that allows a user not only to numerically evaluate
equations, but to automatically perform unit analysis and conversion as well,
with most of the fundamental physical constants built in.


title:
Il corso di Fisica teorica di Ettore Majorana: il ritrovamento del
  Documento Moreno

abstract:
  We analyze in some detail the course of Theoretical Physics held by Ettore
Majorana at the University of Naples in 1938, just before his mysterious
disappearance. In particular we give an account of the recently retrieved
"Moreno Paper", where the lecture notes are reported. Six of these lectures are
not present in the collection of the original manuscripts deposited at the
Domus Galilaeana in Pisa, consisting of only ten lectures.


title: Plateau Instability of Liquid Crystalline Cylinder in Magnetic Field

abstract:
  The capillary instability of a LC cylinder in magnetic field is considered
using an energy approach. The boundary problem is solved in the linear
approximation of the anisotropy $\chi_a$ of the magnetic susceptibility $\chi$.
The effect of anisotropy, in the region $1\gg|\chi|>|\chi_a|\gg \chi^2$, can be
strong enough to counteract and even reverse the tendency of the field to
enhance stabilization by enlarging the cut--off wave number $k_s$ beyond the
conventional one set by Rayleigh.


title: Rain initiation time in turbulent warm clouds

abstract:
  We present a mean-field model that describes droplet growth due to
condensation and collisions and droplet loss due to fallout. The model allows
for an effective numerical simulation. We study how the rain initiation time
depends on different parameters. We also present a simple model that allows one
to estimate the rain initiation time for turbulent clouds with an inhomogeneous
concentration of cloud condensation nuclei. In particular, we show that
over-seeding even a part of a cloud by small hygroscopic nuclei one can
substantially delay the onset of precipitation.


title: Proposal of atomic clock in motion: Time in moving clock

abstract:
  The time in an atomic clock in motion is discussed using the analogy of a
sing around sound source. Sing around frequency is modified according to the
motion of the sing around sound source, using the Lorentz transformation
equation. Thus, if we use the sing around frequency as a reference, we can
define the reference time. We propose that the time delay of an atomic clock in
motion be derived using the sing around method. In this letter, we show that
time is defined by a combination of light speed and motion.


title:
From the double-stranded helix to the chiral nematic phase of B-DNA: a
  molecular model

abstract:
  B-DNA solutions of suitable concentration form left-handed chiral nematic
phases (cholesterics). Such phases have also been observed in solutions of
other stiff or semiflexible chiral polymers; magnitude and handedness of the
cholesteric pitch are uniquely related to the molecular features. In this work
we present a theoretical method and a numerical procedure which, starting from
the structure of polyelectrolytes, lead to the prediction of the cholesteric
pitch. Molecular expressions for the free energy of the system are obtained on
the basis of steric and electrostatic interactions between polymers; the former
are described in terms of excluded volume, while a mean field approximation is
used for the latter. Calculations have been performed for 130 bp fragments of
B-DNA. The theoretical predictions provide an explanation for the experimental
behavior, by showing the counteracting role played by shape and charge
chirality of the molecule.