title: Double resonance frequency shift in a hydrogen maser

abstract:
  We use the dressed atom formalism to calculate the frequency shift in a
hydrogen maser induced by applied radiation near the Zeeman frequency, and find
excellent agreement with a previous calculation made in the bare atom basis.
The maser oscillates on the Delta_F = 1, Delta_m_F = 0 hyperfine transition,
while the applied field is swept through the F = 1, Delta_m_F = \pm 1 Zeeman
resonance. We determine the effect of the applied field on the Zeeman levels
using the dressed atom picture, and then calculate the maser frequency shift by
coupling the dressed states to the microwave cavity. Qualitatively, the
dressed-atom analysis gives a new and simpler physical interpretation of this
double resonance process, which has applications in precision hydrogen Zeeman
spectroscopy, e.g., in fundamental symmetry tests.


title:
Explanation of Faraday's Experiment by the Time-Space Model of Wave
  Propagation

abstract:
  It is shown by the means of Time-Space Model of Wave Propagation the
underlying phenomena of the alternating current's origin in famous Faraday's
experiment.


title: The Problem of Big Bang Matter vs. AntiMatter Symmetry

abstract:
  -The favored Big Bang concept is that the original symmetry was skewed, the
universe now being all matter, all antimatter having annihilated.
  -The mechanism of matter/antimatter annihilation is analyzed. A total
annihilation of original antimatter could not have occurred; the skewing is
unnecessary; and the universe must contain equally both forms of matter.
  -Current detection of cosmic matter/antimatter annihilations is Gamma Ray
Bursts [GRB's]. However, the conviction that the universe is now all matter
with no antimatter has left that possibility rejected and uninvestigated and
left standing the massive supernovae core collapse hypothesis for GRB's.
  -It has recently been reported that the rate of GRB's increases with red
shift z for z = 0 to 4 as (1 + z)^1.5. The indication is that the rate
increases significantly with time into the past at least back to z = 4 [and
probably back to the Big Bang].
  -That finding is inconsistent with the massive supernovae core collapse
hypothesis for GRB's and supports GRB's being cosmic matter/antimatter
annihilations.


title:
Lorentz angle measurements in irradiated silicon detectors between 77 K
  and 300 K

abstract:
  Future experiments are using silicon detectors in a high radiation
environment and in high magnetic fields. The radiation tolerance of silicon
improves by cooling it to temperatures below 180 K. At low temperatures the
mobility increases, which leads to larger deflections of the charge carriers by
the Lorentz force. A good knowledge of the Lorentz angle is needed for design
and operation of silicon detectors. We present measurements of the Lorentz
angle between 77 K and 300 K before and after irradiation with a primary beam
of 21 MeV protons.


title: The BaBar Calorimeter Light Pulser System

abstract:
  To make precision measurements with a CsI(Tl) calorimeter in a high
luminosity environment requires that the crystals are well calibrated and
continually monitored for radiation damage. This should not effect the total
integrated luminosity which is particularly important for the \babar
calorimeter to enable it to make CP violation measurements in the $B$ meson
system. To achieve this goal a fibre-optic light pulser system was designed
using xenon flash lamps as the light source. A novel light distribution method
was developed using an array of graded index microlenses. Some initial results
from performance studies are presented.


title: Lattice Matching with a Quadrupole Missing

abstract:
  The lattice for the present design of the TESLA Linear Collider with
integrated X-Ray Laser Facility is basically a FODO structure with constant
beta-function. There are more than 800 individually powered superconducting
quadrupoles to focus the beam in the two main linear accelerators (each with a
length of 15 km). For the availability of the beams it is important that a
power supply failure or even a magnet failure does not cause a significant down
time of the linac. It is demonstrated that the beta-function can be matched
with a quadrupole "missing". One part of the main linac (up-to 50 GeV) will be
used to accelerate the High Energy Physics beam and the Free Electron Laser
drive beam with different accelerating gradients. Therefore the betatron phase
advance will be 60 deg. or 90 deg. depending on the beam energy. It is shown
that even in that case it is possible to match the lattice simultaneously for
both beams with a quadrupole missing.


title: New Clock Comparison Tests of Lorentz Symmetry

abstract:
  We present two new measurements constraining Lorentz and CPT violation using
the Xe-129 / He-3 Zeeman maser and atomic hydrogen masers. Experimental
investigations of Lorentz and CPT symmetry provide important tests of the
framework of the standard model of particle physics and theories of gravity.
The two-species Xe-129 / He-3 Zeeman maser bounds violations of CPT and Lorentz
symmetry of the neutron at the 10^-31 GeV level. Measurements with atomic
hydrogen masers provide a clean limit of CPT and Lorentz symmetry violation of
the proton at the 10^-27 GeV level.

categories: physics.atom-ph hep-ex hep-ph physics.gen-ph


title: New Clock Comparison Searches for Lorentz and CPT Violation


title: Further Studies on the Prospects for Many-TeV Muon Colliders

abstract:
  New self-consistent parameter sets are presented and discussed for muon
collider rings at center-of-mass energies of 10, 30 and 100 TeV. All three
parameter sets attain luminosities of 3 x 10^35 /cm^2/s. The parameter sets
benefit from new insights gained at the HEMC'99 workshop that considered the
feasibility of many-TeV muon colliders.


title:
The Orientation of Local Spatial Reference Frames in Quantum
  Teleportation

abstract:
  Bennett et al.'s original article on quantum teleportation did not address
explicitly synchronizing the orientation of the local spatial reference frames
from and to which teleportaton occurs where the state teleported is spin 1/2
along the z axis. They wrote that only two bits of information need to be
conveyed classically where the state to be teleported concerns spin 1/2 along
the z axis. That only two bits of information need to be classically conveyed
could imply that such synchronization is not needed for it would require more
classically conveyed information. A gedankenexperiment is presented regarding
the orientation of the local spatial reference frames exploring whether such
synchronization is not needed even though it was apparently assumed by Bennett
et al. that it was required. It is often assumed that there is an absolute, as
opposed to a relative, orientation of objects in space. This assumption should
be open to empirical test, especially in view of evidence in psychology that
the orientation of objects in space is not absolute.


title: Cosmic Acceleration: A Natural Remedy For Horizon and Flatness Problems

abstract:
  The standard big bang cosmology has been greatly successful in explaining
many observational aspects of the real universe. However, two particular
diffficulties faced by it are the so-called ``horizon'' and ``flatness''
problems. By assuming that the recently found cosmic acceleration to be a
genuine and ever present effect, we show that, the resultant modified Friedman
model is free from both the above referred problems, and there is no need to
invoke the additional ``inflationary'' initial phase as a seperate ingredient.
The important cosmological milestones of the standard big babg cosmology (which
predicts cosmic deceleration) like GUT symmetry breaking epoch or radiation
matter decoupling epoch may remain more or less unchanged in the modified
cosmology in terms of redshift values. However, in terms of cosmic time $t$,
all such epochs occur earlier as the universe becomes older in this case.


title:
Scaling-violation phenomena and fractality in the human posture control
  systems

abstract:
  By analyzing the movements of quiet standing persons by means of wavelet
statistics, we observe multiple scaling regions in the underlying body
dynamics. The use of the wavelet-variance function opens the possibility to
relate scaling violations to different modes of posture control. We show that
scaling behavior becomes close to perfect, when correctional movements are
dominated by the vestibular system.


title: The Spallation Neutron Source: A Powerful Tool for Materials Research

abstract:
  The wavelengths and energies of thermal and cold neutrons are ideally matched
to the length and energy scales in the materials that underpin technologies of
the present and future: ranging from semiconductors to magnetic devices,
composites to biomaterials and polymers. The Spallation Neutron Source (SNS)
will use an accelerator to produce the most intense beams of neutrons in the
world when it is complete at the end of 2005. The project is being built by a
collaboration of six U.S. Department of Energy laboratories. It will serve a
diverse community of users drawn from academia, industry, and government labs
with interests in condensed matter physics, chemistry, engineering materials,
biology, and beyond.


title:
Ultracold Metastable Calcium Ensembles, a Medium for Matter Wave
  Amplification ?

abstract:
  We propose an experimental implementation of matter wave amplification by
optical pumping (MAO) with metastable calcium atoms. First experimental results
indicate that pumping rates can be significantly higher than in previous
experimental schemes and let it appear promising that the threshold condition
for generation of degeneracy can be reached.


title: Predictability, complexity and learning

abstract:
  We define {\em predictive information} $I_{\rm pred} (T)$ as the mutual
information between the past and the future of a time series. Three
qualitatively different behaviors are found in the limit of large observation
times $T$: $I_{\rm pred} (T)$ can remain finite, grow logarithmically, or grow
as a fractional power law. If the time series allows us to learn a model with a
finite number of parameters, then $I_{\rm pred} (T)$ grows logarithmically with
a coefficient that counts the dimensionality of the model space. In contrast,
power--law growth is associated, for example, with the learning of infinite
parameter (or nonparametric) models such as continuous functions with
smoothness constraints. There are connections between the predictive
information and measures of complexity that have been defined both in learning
theory and in the analysis of physical systems through statistical mechanics
and dynamical systems theory. Further, in the same way that entropy provides
the unique measure of available information consistent with some simple and
plausible conditions, we argue that the divergent part of $I_{\rm pred} (T)$
provides the unique measure for the complexity of dynamics underlying a time
series. Finally, we discuss how these ideas may be useful in different problems
in physics, statistics, and biology.

categories: physics.data-an cond-mat.dis-nn cond-mat.other cs.LG nlin.AO q-bio.OT


title: Magnetic Field of Relativistic Nonlinear Plasma Wave

abstract:
  Longitudinal and transverse behavior of magnetic field of relativistic
nonlinear three-dimensional plasma wave is investigated. It is shown that the
magnetic field of the wave is different from zero and performs higher frequency
oscillations compared to the plasma electron frequency. An increase in the
nonlinearity leads to strengthening of magnetic field. The oscillations of
magnetic field in transverse direction arise, that caused by the phase front
curving of nonlinear plasma wave. The numerical results well conform with
predictions of the analytical consideration of weakly-nonlinear case.


title: Laser Cooling of TeV Muons

abstract:
  We show that Compton scattering can be used to cool TeV-scale muon beams, and
we derive analytical expressions for the equilibrium transverse angular spread,
longitudinal energy spread, and power requirements. We find that a factor of a
few thousand reduction in emittance is possible for a 3 TeV muon collider.


title: Extinction theorem for ultrafast pulses

abstract:
  Instead of using frequency dependent refractive index, we propose to use the
extinction theorem to describe reflection and transmission of an ultrashort
pulse passing through the boundary. When the duration of the pulse is
comparable with the relaxation time, the results differ significantly from
those given by the traditional method, especially if the carrier frequency is
close to an absorbtion line. We compare the two approaches using the data of
GaAs in the infrared domain.


title: Complete Entanglement-Based Communication With Security

abstract:
  If, due to some catastrophe, our classical communication system is destroyed
but quantum entangled state survived, in that entanglement age, it is widely
believed, the whole world would be communication less. It is discussed that
complete entanglement based communication even with security is possible in
that scenario. In this context, the notion of cheating-free Bell's inequality
test is introduced.


title: Optimization of Trading Physics Models of Markets

abstract:
  We describe an end-to-end real-time S&P futures trading system. Inner-shell
stochastic nonlinear dynamic models are developed, and Canonical Momenta
Indicators (CMI) are derived from a fitted Lagrangian used by outer-shell
trading models dependent on these indicators. Recursive and adaptive
optimization using Adaptive Simulated Annealing (ASA) is used for fitting
parameters shared across these shells of dynamic and trading models.

categories: physics.comp-ph cond-mat.stat-mech cs.CE physics.data-an q-fin.ST


title:
About nondegenerative four photon mixing gain spectroscopy of the SF_6
  molecules

abstract:
  Infrared-infrared double resonance measurements of the $\nu_3$ absorption
band of $SF_6$ using a $CO_2$ TEA laser radiation have been carried out. The
results obtained in the present and in some earlier works are discussed taking
into account existence of a wide component of lines, nondegenerative four
photon mixing (NFPM) and time invariance violation in the photon-molecule
interactions. It is proposed to use the NFPM effect in investigations of the
shape of the optical transition in polyatomic molecules and especially for
evaluation of the homogeneous width of the wide component of lines. The need
and problems of experimental study of existing effects of the T-invariance
violation in optics are discussed.


title: The Nobel Prize in Physics 1999

abstract:
  The last Nobel Prize of the Millenium in Physics has been awarded jointly to
Professor Gerardus 't Hooft of the University of Utrecht in Holland and his
thesis advisor Professor Emeritus Martinus J.G. Veltman of Holland. According
to the Academy's citation, the Nobel Prize has been awarded for 'elucidating
the quantum structure of electroweak interaction in Physics'. It further goes
on to say that they have placed particle physics theory on a firmer
mathematical foundation. In this short note, we will try to understand both
these aspects of the award. The work for which they have been awarded the Nobel
Prize was done in 1971. However, the precise predictions of properties of
particles that were made possible as a result of their work, were tested to a
very high degree of accuracy only in this last decade. This was done in a
series of measurements in the experiments in the accelerator laboratories at
CERN (Geneva) and Fermilab. To understand the full significance of this Nobel
Prize, we will have to summarise briefly the developement of our current
theoretical framework about the basic constituents of matter and the forces
which hold them together. In fact the path can be partially traced in a chain
of Nobel prizes starting from one in 1965 to S. Tomonaga, J. Schwinger and R.
Feynman, to the one to S.L. Glashow, A. Salam and S. Weinberg in 1979, and then
to C. Rubia and Simon van der Meer in 1984 ending with the current one.


title:
Asymmetric Collision of Concepts: Why Eigenstates Alone are Not Enough
  for Neutrino Flavor Oscillations

abstract:
  The symmetry of the problem of the apparent deficit in upward-going
atmospheric muon neutrinos reveals two possible, nonexclusive kinds of
solution: Nonlinearity in distance or nonlinearity in angle of observation.
  Nonlinearity in distance leads to the most popular theory for the atmospheric
problem, neutrino flavor oscillations. If the observed deficit is caused by
oscillations and not, say, flavor-changing or other weak-force scattering,
neutrinos must be massive. But, if flavor oscillations occur in vacuum, all
oscillating neutrinos must have exactly equal mass. Theories of oscillation in
matter such as the Mikheyev-Smirnov-Wolfenstein (MSW) effect do not work in
vacuum. This is the conceptual conflict of kinematics versus vacuum
oscillations. Flavor-changing oscillations like those of the
Cabibbo-Kobayashi-Maskawa (CKM) quark theory become possible in vacuum if
freely propagating neutrinos may be associated with local substructure.
  Nonlinearity in angle of observation leads to a simple prediction of an
excess of horizontal muon flavor. This and other angle-based effects should be
observable at Super-Kamiokande or other instruments which can measure
atmospheric flux by flavor.


title: Polarization Elements-A Group Theoretical Study

abstract:
  The Classification of Polarization elements, the polarization affecting
optical devices which have a Jones matrix representation, according to the
types of eigenvectors they possess, is given a new visit through the
Group-theoretical connection of polarization elements. The diattenuators and
retarders are recognized as the elements corresponding to boosts and rotations
respectively. The structure of homogeneous elements other than diattenuators
and retarders are identified by giving the quaternion corresponding to these
elements. The set of degenerate polarization elements is identified with the so
called `null' elements of the Lorentz Group. Singular polarization elements are
examined in their more illustrative Mueller matrix representation and finally
the eigenstructure of a special class of singular Mueller matrices is studied.


title: Development of rebunching cavities at IAP

abstract:
  A focus of work at IAP has been the development and optimization of spiral
loaded cavities since the 1970s [A. Schempp et al, NIM 135, 409 (1976)]. These
cavities feature a high efficiency, a compact design and a big variety of
possible fields of application. They find use both as bunchers and post
accelerators to vary the final energy of the beam. In comparison to other
available designs, the advantage of these structures lies in their small size.
Furthermore they can easily be tuned to the required resonance frequency by
varying the length of the spiral. Due to the small size of the cavities the
required budget can also be kept low. Here, two slightly different types of
spiral loaded cavities, which were built for the REX-ISOLDE project at CERN and
the intensity upgrade program at GSI are being discussed.


title: Measurement of the temporal response of ferroelectric cathodes

abstract:
  Ferroelectric ceramics are tested as photocathodes at INFN Frascati
Laboratories. In order to characterize them for use in linac injectors it is
important to measure the temporal shape of the emitted current. With a duration
of the laser pulse of 25 ps, the required resolution is a few ps. An apparatus
has been set up for the purpose, consisting of a 30 kV electron gun, a
microwave deflecting cavity which translates the temporal distribution of the
electron bunch into a spatial one, a fluorescent screen on which the deflected
beam traces a sector of a circle and various focusing and charge measuring
items. The image on the screen is detected via a CCD camera and a frame
grabber. We describe the performance of the apparatus and some preliminary
temporal distribution measurements.


title:
Strong Discontinuities in the Complex Photonic Band Structure of
  Transmission Metallic Gratings

abstract:
  Complex photonic band structures (CPBS) of transmission metallic gratings
with rectangular slits are shown to exhibit strong discontinuities that are not
evidenced in the usual energetic band structures. These discontinuities are
located on Wood's anomalies and reveal unambiguously two different types of
resonances, which are identified as horizontal and vertical surface-plasmon
resonances. Spectral position and width of peaks in the transmission spectrum
can be directly extracted from CPBS for both kinds of resonances.


title:
A Superconductive, Low Beta Single Gap Cavity for a High Intensity
  Proton Linac

abstract:
  A single gap, 352 MHz superconducting reentrant cavity for 5-100 MeV beams
has been designed and it is presently under construction. This development is
being done in the framework of a 30 mA proton linac project for nuclear waste
transmutation. Mechanical, cryogenic and rf design characteristics of such
cavities will be described.


title:
A Simple Model for the Non-Retarded Dispersive Force between an
  Electrically Polarizable Atom and a Magnetic Polarizable One

abstract:
  It is well known that for the case of two neutral but electrically
polarizable atoms the consideration or not of retardation effects on the
dispersive van der Waals force between them leads essentially to different
power laws for the forces; while the retarded force is proportional to $1/r^8$,
where $r$ is the distance between the atoms, the non-retarded force is
proportional to $1/r^7$. Here we consider the (repulsive) dispersive force
between an electrically polarizable atom and a magnetically polarizable one and
show that, in contrast to the previous case, a quite unexpected result appears,
namely: while the retarded force is still proportional to $1/r^8$, the
non-retarded force is proportional to $1/r^5$. We employ a semiclassical method
based on the fluctuating dipole model for both atoms.


title: Measurement of the 21Ne Zeeman frequency shift due to Rb-21Ne collisions

abstract:
  We compared the frequency shift of the 21Ne Zeeman resonance induced by
polarized Rb vapor to the shift induced in the 3He Zeeman resonance. The 3He/Rb
shift has recently been measured with high precision, permitting the conversion
of our differential measurement to an absolute value for the 21Ne/Rb shift. We
report a value of K = 31.8 +/- 2.8 for the Rb/21Ne enhancement factor at a
temperature of 124.8 +/- 1.9 C. We propose high-precision differential contact
shift measurements, the absolute accuracy of which would be limited by the
error in the 3He contact shift.


title: How high the temperature of a liquid be raised without boiling?

abstract:
  How high the temperature of a liquid be raised beyond its boiling point
without vaporizing (known as the limit of superheat) is an interesting subject
of investigation. A new method of finding the limit of superheat of liquids is
presented here. The superheated liquids are taken in the form of drops
suspended in visco elastic gel. The nucleation is detected acoustically by a
sensitive piezo-electric transducer, coupled to a multi channel scaler and the
nucleation is observed as a funtion of time and with increase of temperature.
The limit of superheat measured by the present method supersedes all other
measurements and theoretical predictions in reaching closest to the critical
temperature and warrants improved theoretical predictions.


title:
Theory of periodic swarming of bacteria: application to Proteus
  mirabilis

abstract:
  The periodic swarming of bacteria is one of the simplest examples for pattern
formation produced by the self-organized collective behavior of a large number
of organisms. In the spectacular colonies of Proteus mirabilis (the most common
species exhibiting this type of growth) a series of concentric rings are
developed as the bacteria multiply and swarm following a scenario periodically
repeating itself. We have developed a theoretical description for this process
in order to get a deeper insight into some of the typical processes governing
the phenomena in systems of many interacting living units. All of our
theoretical results are in excellent quantitative agreement with the complete
set of available observations.


title: Development of Rebunching Cavities at IAP


title: Unconditionally secure quantum bit commitment is simply possible

abstract:
  Mayers, Lo and Chau proved unconditionally secure quantum bit commitment is
impossible. It is shown that their proof is valid only for a particular model
of quantum bit commitment encoding, in general it does not hold good. A
different model of unconditionally secure quantum bit commitment - both
entanglement and disentanglement-based - is presented. Even cheating can be
legally proved with some legal evidences. Unconditionally secure quantum bit
commitment can be established on the top of unconditionally secure quantum coin
tossing, which is also claimed to be two-way impossible.


title: Entanglement versus disentanglement: Quantum Cryptography

abstract:
  In quantum information, the role of entanglement and disentanglement is
itself a subject of research and debate. Earlier works on quantum cryptography
have almost established that entanglement has no special advantage in quantum
cryptography. In this paper we reveal that entanglement is better ingredient
than disentanglement for our alternative quantum cryptography.


title: Critical dynamics of two-replica cluster algorithms

abstract:
  The dynamic critical behavior of the two-replica cluster algorithm is
studied. Several versions of the algorithm are applied to the two-dimensional,
square lattice Ising model with a staggered field. The dynamic exponent for the
full algorithm is found to be less than 0.4. It is found that odd translations
of one replica with respect to the other together with global flips are
essential for obtaining a small value of the dynamic exponent.


title: Threshold amplitudes for transition to turbulence in a pipe

abstract:
  Although flow in a circular pipe is stable to infinitesimal perturbations, it
can be excited to turbulence by finite perturbations whose minimal amplitude
shrinks as R goes to infinity (R = Reynolds number). Laboratory experiments
have appeared to disagree with one another and with theoretical predictions
about the dependence of this minimal amplitude on $R$, with published results
ranging approximately from $R^{-1/4}$ to $R^{-3/2}$. Here it is shown that
these discrepancies can be explained by the use of different definitions of
amplitude by different authors. An attempt is made to convert the existing
results to a uniform definition of amplitude, the nondimensionalized $L^2$
definition common in the theoretical literature. Although subtleties in the
physics raise some questions, agreement appears to be reached on a minimal
amplitude that scales as $R^{-3/2 \pm 0.3}$.


title: A Note on $3 + 1$ Dimensionality

abstract:
  Recent work by Castro, Granik and El Naschie has given a rationale for the
three dimensionality of our physical space within the framework of cantorian
fractal space time using similar ideas of quantized fractal space time and
noncommutativity. We also deduce the same result. Interestingly this is also
seen to provide a rationale for an unproven conjecture of Poincare.


title: The Jefferson Lab 1 kW IR FEL

abstract:
  The Jefferson Lab (JLab) IR Demo Free Electron Laser (FEL) has completed
commissioning and is initiating user service. The FEL - a high repetition rate,
low extraction efficiency wiggler-driven optical cavity resonator - produces
over 1 kW of tuneable light on intervals in a 3-6 micron wavelength range. It
is driven by a 35-48 MeV, 5 mA superconducting RF (SRF) based energy-recovering
continuous wave (CW) electron linac. The driver accelerator meets requirements
imposed by low energy, high current, and a demand for stringent beam control at
the wiggler and during energy recovery. These constraints are driven by the
need for six-dimensional phase space management, the existence of deleterious
collective phenomena (space charge, wakefields, beam break-up, and coherent
synchrotron radiation), and interactions between the FEL and the accelerator
RF. We will detail the system design, relate commissioning highlights, and
discuss present performance.


title:
Re-examination of log-periodicity observed in the seismic precursors of
  the 1989 Loma Prieta earthquake

abstract:
  Based on several empirical evidence, a series of papers has advocated the
concept that seismicity prior to a large earthquake can be understood in terms
of the statistical physics of a critical phase transition. In this model, the
cumulative Benioff strain (BS) increases as a power-law time-to-failure before
the final event. This power law reflects a kind of scale invariance with
respect to the distance to the critical point. A few years ago, on the basis of
a fit of the cumulative BS released prior to the 1989 Loma Prieta earthquake,
Sornette and Sammis [1995] proposed that this scale invariance could be
partially broken into a discrete scale invariance (DSI). The observable
consequence of DSI takes the form of log-periodic oscillations decorating the
accelerating power law. They found that the quality of the fit and the
predicted time of the event are significantly improved by the introduction of
log-periodicity. Here, we present a battery of synthetic tests performed to
quantify the statistical significance of this claim. We find that log-periodic
oscillations with frequency and regularity similar to those of the Loma Prieta
case are very likely to be generated by the interplay of the low pass filtering
step due to the construction of cumulative functions together with the
approximate power law acceleration. Thus, the single Loma Prieta case alone
cannot support the initial claim and additional cases and further study are
needed to increase the signal-to-noise ratio if any. The present study will be
a useful methodological benchmark for future testing of additional events when
the methodology and data to construct reliable Benioff strain function become
available.


title: Re-examination of the "3/4-law" of Metabolism

abstract:
  We examine the scaling law $B \propto M^{\alpha}$ which connects organismal
metabolic rate $B$ with organismal mass $M$, where $\alpha$ is commonly held to
be 3/4. Since simple dimensional analysis suggests $\alpha=2/3$, we consider
this to be a null hypothesis testable by empirical studies. We re-analyze data
sets for mammals and birds compiled by Heusner, Bennett and Harvey, Bartels,
Hemmingsen, Brody, and Kleiber, and find little evidence for rejecting
$\alpha=2/3$ in favor of $\alpha=3/4$. For mammals, we find a possible
breakdown in scaling for larger masses reflected in a systematic increase in
$\alpha$. We also review theoretical justifications of $\alpha=3/4$ based on
dimensional analysis, nutrient-supply networks, and four-dimensional biology.
We find that present theories for $\alpha=3/4$ require assumptions that render
them unconvincing for rejecting the null hypothesis that $\alpha=2/3$.


title: Slow light

abstract:
  We present a brief classical discussion of a process to reduce the group
velocity of an electromagnetic pulse by many orders of magnitude.


title: Suggestion for a Fast Heuristic for the Hamiltonian Cycle Problem

abstract:
  Some years ago I demonstrated a simulated annealing heuristic for the
Hamiltonian cycle problem (Science 273, 413 (1996)). Here I propose an improved
version of this heuristic.


title:
Formation of Structure in Snowfields: Penitentes, Suncups, and Dirt
  Cones

abstract:
  Penitentes and suncups are structures formed as snow melts, typically high in
the mountains. When the snow is dirty, dirt cones and other structures can form
instead. Building on previous field observations and experiments, this work
presents a theory of ablation morphologies, and the role of surface dirt in
determining the structures formed. The glaciological literature indicates that
sunlight, heating from air, and dirt all play a role in the formation of
structure on an ablating snow surface. The present work formulates a
mathematical model for the formation of ablation morphologies as a function of
measurable parameters. The dependence of ablation morphologies on weather
conditions and initial dirt thickness are studied, focusing on the initial
growth of perturbations away from a flat surface. We derive a single-parameter
expression for the melting rate as a function of dirt thickness, which agrees
well with a set of measurements by Driedger. An interesting result is the
prediction of a dirt-induced travelling instability for a range of parameters.


title: Rectangular Waveguide HOM Couplers for a TESLA Superstructure

abstract:
  Some modifications of a Rectangular Waveguide HOM couplers for TESLA
superstructure have been investigated. These RWG HOM couplers are to be
installed between the cavities of the superstructure and also at the both ends
of it. We investigated a RWG HOM coupler attached to the beam pipe through the
slots orientated along beam pipe axis (longitudinal slots), perpendicular to it
(azimutal slots) and at some angle to this axis. For dipole modes of both
polarizations damping two RWG in every design were used. This paper presents
the results obtained for scaled-up setup at 3 GHz at room temperature. The
advantages of HOM coupler with longitudinal slots for damping dipole modes and
compact HOM coupler with slots at some angle to the axis are shown. Arrangement
of HOM coupler in cryostat and heating due to HOM and FM losses are presented.
Calculations and design of the feeding RWG coupler for superstructure are also
presented.


title:
Circular photogalvanic effect induced by monopolar spin orientation in
  p-GaAs/AlGaAs MQW

abstract:
  The circular photogalvanic effect (CPGE) has been observed in (100)-oriented
$p$-GaAs/AlGaAs quantum wells at normal incidence of far-infrared radiation. It
is shown that monopolar optical spin orientation of free carriers causes an
electric current which reverses its direction upon changing from left to right
circularly polarized radiation. CPGE at normal incidence and the occurence of
the linear photogalvanic effect indicate a reduced point symmetry of studied
multi-layered heterostructures. As proposed, CPGE can be utilized to
investigate separately spin polarization of electrons and holes and the
symmetry of quantum wells.


title:
Two large-area anode-pad MICROMEGAS chambers as the basic elements of a
  pre-shower detector

abstract:
  The design of a detector based on MICROMEGAS (MICRO MEsh GAseous Structure)
technology is presented. Our detector is characterized by a large active area
of 398(\times)281 mm(^{2}), a pad read-out with 20(\times)22 mm(^{2})
segmentation, and an uniform amplification gap obtained by insulating spacers
(100 (\mu)m high and 200 (\mu)m in diameter). The performances of several
prototypes have been evaluated under irradiation with secondary beams of 2
GeV/c momentum charged pions and electrons. We consider such a detector as the
basic element for a pre-shower detector to equip the PHOton Spectrometer (PHOS)
of the ALICE experiment. Its assets are modularity, small amount of material,
robustness and low cost.


title: Acceleration for the mu-Storage Ring Neutrino Source

abstract:
  A muon storage ring neutrino source uses an induction linac for muon capture,
a 200 MHz copper cavity system for cooling, and 200 and 400 MHz superconducting
rf systems for acceleration to a final energy of up to 50 GeV. These systems
and their requirements are discussed in this paper.


title:
A Fast Switchyard for the TESLA FEL-Beam Using a Superconducting
  Transverse Mode Cavity

abstract:
  In the present design of the TESLA Linear Collider with integrated X-ray
Laser Facility it is necessary that 1 ms long bunch trains with about 10000
bunches are generated and distributed to several free electron laser (FEL) beam
lines. The different scientific applications of the X-ray FELs need specific
filling patterns of the bunches in the bunch train. It is shown that a fast
switch-yard based on a superconducting transverse mode cavity can be used to
generate the required bunch pattern in a flexible way while keeping the beam
loading in the main linear accelerator constant. The conceptual design of the
beam optics and the transverse mode cavity are presented.


title: On electromagnetic induction

abstract:
  A general law for electromagnetic induction phenomena is derived from Lorentz
force and Maxwell equation connecting electric field and time variation of
magnetic field. The derivation provides with a unified mathematical treatment
the statement according to which electromagnetic induction is the product of
two independent phenomena: time variation of magnetic field and effects of
magnetic field on moving charges. The general law deals easily-without ad hoc
assumptions-with typical cases usually considered as exceptions to the flux
rule and contains the flux rule as a particular case.


title: Quadrupole Misalignments and Steering in Long Linacs

abstract:
  We present a study of orbit jitter and emittance growth in a long linac
caused by misalignment of quadrupoles. First, assuming a FODO lattice, we
derive analytical formulae for the RMS deviation of the orbit and the emittance
growth caused by random uncorrelated misalignments of all quadrupoles. We then
consider an alignment algorithm based on minimization of BPM readings with a
given BPM resolution and finite mover steps.


title:
Suppression of beam breakup instability in a long train by introducing
  energy spread between the bunches

abstract:
  Interaction between the bunches in the NLC main linac via long range
wakefields can cause a beam breakup instability. Although the magnitude of the
long range wakefields for an ideal NLC structure is below the instability
threshold, the wake increases when structure manufacturing errors are taken
into account. In case of large errors, the developing instability can result in
the projected emittance dilution of the bunch train. To suppress the
instability, we propose to introduce an energy spread between the bunches,
similar to the BNS energy spread for damping of the beam breakup within a
single bunch. Based on simple estimates, we show that the energy spread of
order of 1-2% should be enough for suppression of the instability. The results
of computer simulations with the simulation code LIAR confirm theoretical
estimates and indicate that both the tolerances for structure misalignments and
the incoming beam jitter can be considerably loosened by introducing the energy
spread within the beam.


title:
Numerical Analysis of a Beam-Energy-Spread Monitor Using Multi-Stripline
  Electrodes

abstract:
  A beam-energy-spread monitor is under development in order to control and
stabilize the energy spread of high-current single-bunch electron beams for
producing a sufficient number of positrons. The author has proposed a new
monitor using multi-stripline electrodes in order to reinforce this purpose.
This report describes the basic design of the monitor based on a numerical
analysis. The analysis result shows that the resolution of an energy-spread
measurement is expected to be less than 0.3% for nominal operation conditions.


title: Universal quantification for deterministic chaos in dynamical systems

abstract:
  A cell dynamical system model for deterministic chaos enables precise
quantification of the round-off error growth,i.e., deterministic chaos in
digital computer realizations of mathematical models of continuum dynamical
systems. The model predicts the following: (a) The phase space trajectory
(strange attractor) when resolved as a function of the computer accuracy has
intrinsic logarithmic spiral curvature with the quasiperiodic Penrose tiling
pattern for the internal structure. (b) The universal constant for
deterministic chaos is identified as the steady-state fractional round-off
error k for each computational step and is equal to 1 /sqr(tau) (=0.382) where
tau is the golden mean. (c) The Feigenbaum's universal constants a and d are
functions of k and, further, the expression 2(a**2) = (pie)*d quantifies the
steady-state ordered emergence of the fractal geometry of the strange
attractor. (d) The power spectra of chaotic dynamical systems follow the
universal and unique inverse power law form of the statistical normal
distribution.


title:
A Variational Approach in the Dissipative Nonlinear Schr\"{o}dinger
  Equation

abstract:
  The properties of pulse propagation in a nonlinear fiber including linear
damped term added in the usual nonlinear Schr\"odinger equation is analyzed
analytically. We apply variational modified approach based on the lagrangian
that describe the dynamic of system and with a trial function we obtain a
solution which is more accuracy when compared with a pertubative solution. As a
result, the problem of pulse propagation in a fiber with loss can be described
in good agreement with exact results.


title:
The interpretations by experimenters of experiments on 'time dilation':
  1940-1970 circa

abstract:
  Experimental tests on `time dilation' began in 1938 with Ives and Stilwell's
work of the transverse Doppler effect due to atoms in inertial flight. Rossi
and Hall (1941) inaugurated the era of fast moving elementary particles that
dominated the scene until the discovery of the Mossbauer effect (1957). This
discovery suggested the use of photons emitted without recoil in crystalline
solids for testing both time dilation and gravitational red shift. Finally,
around 1970, Hafele and Keating dealt again with time dilation by sending
macroscopic atomic clocks around the Earth. The interpretations of these
experiments by experimenters have been characterized by the use of additional
hypotheses not necessary for the formal development of the theories under test
(the idea that all clocks measure proper time) or hypotheses completely
extraneous to the theories themselves (the idea that atoms are clocks). If
these assumptions are dropped, it turns out that the only experiments
concerning time dilation are those performed with elementary particles in
inertial flight. The historical and epistemological implications are discussed.


title: Negative Group Velocity

abstract:
  The group velocity for pulses in an optical medium can be negative at
frequencies between those of a pair of laser-pumped spectral lines. The gain
medium then can amplify the leading edge of a pulse resulting in a time advance
of the pulse when it exits the medium, as has been recently demonstrated in the
laboratory. This effect has been called superluminal, but, as a classical
analysis shows, it cannot result in signal propgation at speeds greater than
that of light in vacuum.


title: Energy Absorber R&D

abstract:
  We describe the program of research and development being undertaken by a
consortium of Illinois university groups to develop liquid-hydrogen energy
absorbers for muon-beam cooling for a possible stored-muon-beam neutrino
factory.


title: Multipactoring Code for 3D Accelerating Structures

abstract:
  The simulation code has been developed to investigate possible electron
multi- pacting in the 3D RF cavities using preliminary calculated field
components. The code provides different options of numerical study of the
electron multi- pacting including search of the resonant trajectories and
simulation of an electron multiplication.


title: Heart Rate Variability: Measures and Models

abstract:
  We focus on various measures of the fluctuations of the sequence of intervals
between beats of the human heart, and how such fluctuations can be used to
assess the presence or likelihood of cardiovascular disease. We examine sixteen
such measures and their suitability for correctly classifying heartbeat records
of various lengths as normal or revealing the presence of cardiac dysfunction,
particularly congestive heart failure. Using receiver-operating-characteristic
analysis we demonstrate that scale-dependent measures prove substantially
superior to scale-independent ones. The wavelet-transform standard deviation at
a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32
cycles/interval, turn out to provide reliable results using heartbeat records
just minutes long. We further establish for all subjects that the human
heartbeat has an underlying stochastic origin rather than arising from a
chaotic attractor. Finally, we develop a mathematical point process that
emulates the human heartbeat time series for both normal subjects and
heart-failure patients.

categories: physics.bio-ph nlin.CD physics.data-an physics.med-ph q-bio.QM q-bio.TO


title: Inelastic Collisions of Ultracold Polar Molecules

abstract:
  The collisional stability of ultracold polar molecules in electrostatic traps
is considered. Rate constants for collisions that drive molecules from
weak-field-seeking to strong-field-seeking states are estimated using a simple
model. The rates are found to be quite large, of order 10^{-12} - 10^{-10}
cm^3/sec, and moreover to grow rapidly in an externally applied electric field.
It is argued that these results are generic for polar molecules, and that
therefore polar molecules should be trapped by other than electrostatic means.


title: Recent Advances in Electron and Positron Sources

abstract:
  Recent advances in electron and positron sources have resulted in new
capabilities driven in most cases by the increasing demands of advanced
accelerating systems. Electron sources for brighter beams and for high
average-current beams are described. The status and remaining challenges for
polarized electron beams are also discussed. For positron sources, recent
activity in the development of polarized positron beams for future colliders is
reviewed. Finally, a new proposal for combining laser cooling with beam
polarization is presented.


title:
Four-wave mixing at maximum coherence and eliminated Doppler broadening
  controlled with the driving fields

abstract:
  New feasibity of coherent quantum control of four-wave mixing processes in a
resonant Doppler-broadened medium are studied. We propose a technique which
enables one to enhance the quantum efficiency of nonlinear optical conversion.
At the same time, it allows one to decrease the required intensities of the
fundamental beams compared to those necessary in the approach based on coherent
population trapping. The major outcomes of the analysis are illustrated with
numerical simulation addressed within a practical medium.


title: IHEP Experience on Creation and Operation of RFQS

abstract:
  The new 1.8 MeV proton RFQ was completed and started operation in the IHEP in
1997. It was built according to the plan of modernization of the injection
system to the booster of the IHEP proton synchrotron.


title:
Ienversionless gain in an optically-dense resonant Doppler-broadened
  medium

abstract:
  Resonant nonlinear-optical interference processes in four-level
Doppler-broadened media are studied. Specific features of amplification and
optical switching of short-wavelength radiation in a strongly-absorbing
resonant gas under coherent quantum control with two longer wavelength
radiations, are investigated. The major outcomes are illustrated with virtual
experiments aimed at inversionless short-wavelength amplification, which also
address deficiencies in this regard in recent experiments. With numerical
simulations related to the proposed experiment in optically-dense sodium dimer
vapor, we show optimal condition for optical switching and the expected gain of
the probe radiation, which is above the oscillation threshold.


title: New Tasks and New Codes for RFQ Beam Simulation

abstract:
  Proton linear accelerator is the base Accelerator Driven Power System (ADS).
Such ADS are dedicated to various purposes: weapon plutonium conversion,
"energy amplifier", transmutation of radionuclear wastes etc. Solution of these
tasks requires proton beams with energy 1 GeV and average current up to 30 mA.
At the moment there are no problems of fundamental nature in such linac
construction. The main problems have economic and technical aspects. Problems
of CW linac will be demonstrated on the base beam dynamics requirements. New
code package LIDOS.RFQ.Designer makes possible to simulate beam dynamics in RF
fields of real vane shape (including gaps between RFQ section) as well as to
determine channel parameters tolerances for reliable operation


title: RFQ Parameter Choice by Multi-Parameter Optimization

abstract:
  Experts in different accelerator laboratories accumulated wide experience in
RFQ designing. Nevertheless new tasks on high-power, high-energy CW linac
designing (for example, for ADT applications) were appeared recently. Such
accelerators must be practically free of beam losses. This main condition
placed more stringent requirements upon beam quality at the input of each linac
part. Because RFQ is used as beginning part in above accelerators beam
high-quality requirements is related to RFQ primarily. It means that existing
experience in RFQ designing must be enriching by new approaches and new
methodology


title: Measurements of RF Cavity Voltages by X-ray Spectrum Measurements

abstract:
  Measurement of the endpoints of X-ray spectra emitted from RF cavities is a
useful non-invasive technique for measuring peak voltages within the cavities.
The matching of calculated X-ray spectra to measured spectra is described, with
emphasis upon the endpoint region.


title: The "W" Particle and the Weak Force Mechanism

abstract:
  A transformation mechanism is proposed for the "W" weak force IVB particle.
The W is a dense "metric" boson which catalyzes transformations by combining
reactants with virtual particle-antiparticle pairs created from the virtual
vacuum particle-antiparticle "sea". "W" and "Z" IVB mass functions to recreate
the original ("Big Bang") metric energy and density (the "electroweak" force
unification era or symmetric energy state) in which elementary particles were
first formed and transformed, thereby maintaining the invariance of charge and
other conserved parameters of elementary particles in the contemporary
universe. Common weak force decays of leptons, mesons, and baryons are
illustrated. A single electromagnetic transformation is also considered. A
table of three IVB "families" and associated Higgs bosons is appended,
illustrating the (hypothetical) higher-energy structure and cosmological role
of the weak force.


title: Longitudinal Laser Shaping in Laser Wakefield Accelerators

abstract:
  We study the energetics of wake excitation during the laser-plasma
interaction in application to laser wakefield accelerators. We find that both
the wake amplitude and the accelerating efficiency (transformer ratio) can be
maximized by properly shaping the longitudinal profile of the driving laser
pulse. The corresponding family of laser pulse shapes is derived in the
nonlinear regime of laser-plasma interaction. Such shapes provide theoretical
upper limit on the magnitude of the wakefield and efficiency by allowing for
uniform photon deceleration inside the laser pulse. We also construct realistic
optimal pulse shapes that can be produced in finite-bandwidth laser systems.


title: Laser Shaping and Optimization of the Laser-Plasma Interaction

abstract:
  The physics of energy transfer between the laser and the plasma in laser
wakefield accelerators is studied. We find that wake excitation by arbitrary
laser shapes can be parameterized using the total pulse energy and pulse
depletion length. A technique for determining laser profiles that produce the
required plasma excitation is developed. We show that by properly shaping the
longitudinal profile of the driving laser pulse, it is possible to maximize
both the transformer ratio and the wake amplitude, achieving optimal
laser-plasma coupling. The corresponding family of laser pulse shapes is
derived in the nonlinear regime of laser-plasma interaction. Such shapes
provide theoretical upper limit on the magnitude of the wakefield and
efficiency of the accelerating stage by allowing for uniform photon
deceleration inside the laser pulse. We also construct realistic optimal pulse
shapes that can be produced in finite-bandwidth laser systems and propose a
two-pulse wake amplification scheme using the optimal solution.


title: Spatial coherence of thermal near fields

abstract:
  We analyze the spatial coherence of the electromagnetic field emitted by a
half-space at temperature T close to the interface. An asymptotic analysis
allows to identify three different contributions to the cross-spectral density
tensor in the near-field regime. It is shown that the coherence length can be
either much larger or much shorter than the wavelength depending on the
dominant contribution.


title:
Discrete solvent effects on the effective interaction between charged
  colloids

abstract:
  Using computer simulations of two charged colloidal spheres with their
counterions in a hard sphere solvent, we show that the granular nature of the
solvent significantly influences the effective colloidal interaction. For
divalent counterions, the total effective force can become attractive generated
by counterion hydration, while for monovalent counterions the forces are
repulsive and well-described by a solvent-induced colloidal charge
renormalization. Both effects are not contained in the traditional "primitive"
approaches but can be accounted for in a solvent-averaged primitive model.


title:
RBF neural net based classifier for the AIRIX accelerator fault
  diagnosis

abstract:
  The AIRIX facility is a high current linear accelerator (2-3.5kA) used for
flash-radiography at the CEA of Moronvilliers France. The general background of
this study is the diagnosis and the predictive maintenance of AIRIX. We will
present a tool for fault diagnosis and monitoring based on pattern recognition
using artificial neural network. Parameters extracted from the signals recorded
on each shot are used to define a vector to be classified. The principal
component analysis permits us to select the most pertinent information and
reduce the redundancy. A three layer Radial Basis Function (RBF) neural network
is used to classify the states of the accelerator. We initialize the network by
applying an unsupervised fuzzy technique to the training base. This allows us
to determine the number of clusters and real classes, which define the number
of cells on the hidden and output layers of the network. The weights between
the hidden and the output layers, realising the non-convex union of the
clusters, are determined by a least square method. Membership and ambiguity
rejection enable the network to learn unknown failures, and to monitor
accelerator operations to predict future failures. We will present the first
results obtained on the injector.


title: Theory and Suppression of Multibunch Beam Breakup in Linear Colliders

abstract:
  We recently developed an analytic theory of cumulative multibunch beam
breakup that includes a linear variation of transverse focusing across the
bunch train. The focusing variation saturates the exponential growth of the
beam breakup and establishes an algebraic decay of the transverse bunch
displacement versus bunch number. In this paper we illustrate how the focusing
variation works to suppress multibunch beam breakup, as well as how the
mechanism scales with accelerator and beam parameters.


title:
Driver Accelerator Design for the 10 kW Upgrade of the Jefferson Lab IR
  FEL

abstract:
  An upgrade of the Jefferson Lab IR FEL is now under construction. It will
provide 10 kW output light power in a wavelength range of 2-10 microns. The FEL
will be driven by a modest-sized 80-210 MeV, 10 mA energy-recovering
superconducting RF (SRF) linac. Stringent phase space requirements at the
wiggler, low beam energy, and high beam current subject the design to numerous
constraints. These are imposed by the need for both transverse and longitudinal
phase space management, the potential impact of collective phenomena (space
charge, wakefields, beam break-up (BBU), and coherent synchrotron radiation
(CSR)), and interactions between the FEL and the accelerator RF system. This
report addresses these issues and presents an accelerator design solution
meeting the requirements imposed by physical phenomena and operational
necessities.


title: Results of an RF Pulsed Heating Experiment at SLAC

abstract:
  Results are reported from an experiment on RF pulsed heating of copper at
SLAC. Damage in the form of cracks may be induced on the surface after the
application of many pulses of RF. The experiment consists of two circularly
cylindrical cavities operated in the TE011 mode at a resonant frequency of
11.424 GHz. Each cavity received 8.5 MW, 1.2 microsecond pulses at 60 Hz
corresponding to a calculated temperature rise of 120 K on the copper surface.
After 5.5 x 10^7 pulses, the experiment was stopped and the copper surfaces
were examined. Damage is present on the area of the surface where the maximum
heating occurred.


title: Energy stabilization of 1.5 GeV S-Band linac

abstract:
  KEK-ATF is studying low emittance, multi-bunch electron beam for the future
linear collider. The energy instability of the 1.5 GeV linac has been a problem
making the beam injection to the damping ring unstable. Because the unstable
beam generates also large amount of the radiation, the beam current is limited
by the KEK radiation safety policy much lower than what we expect. Stabilizing
the S-band linac is therefore important not only to improve the beam quality,
but also to clear the radiation safety limit to start the multi-bunch
operation.
  We have made various modifications to solve the problem on the electron gun,
modulator, klystron etc. For the modulator, we have developed a feed-forward
controlled De-Q module. This module compensates the voltage jitter by
controlling the deQ timing with a feed-forward circuit because the amount of
the excessive charge up is strongly correlated to the charge up slope that can
be measured prior to the deQ timing. The energy stability was examined and was
improved by a factor of 3, from 0.6% to 0.2% of itself. Modification for the
feed-forward circuit to get more stability was made. The test for the new
circuit is in progress. For the long term instability, phase-lock system for
klystron RF is being installed. In the test operation, it showed a good
performance and compensate the phase drift less than 1 deg.


title: 2.856-GHz Modulation of Conventional Triode Electron Gun

abstract:
  For the generation of picosecond (< 100 ps) electron beam pulses, we studied
the RF modulation of a conventional triode electron gun. The feasibility study
for this scheme has been experimentally investigated by modulating a triode gun
of the Y-824 cathode-grid (KG) structure provided by the CPI Eimac, with
2.856-GHz pulsed RF generated by a solid-state amplifier (SSA). In this paper,
we present the methods and results of this investigation.


title:
Experimental Determination of the Characteristics of a Positron Source
  Using Channeling

abstract:
  Numerical simulations and `proof of principle' experiments showed clearly the
interest of using crystals as photon generators dedicated to intense positron
sources for linear colliders. An experimental investigation, using a 10 GeV
secondary electron beam, of the SPS-CERN, impinging on an axially oriented
thick tungsten crystal, has been prepared and operated between May and August
2000. After a short recall on the main features of positron sources using
channeling in oriented crystals, the experimental set-up is described. A
particular emphasis is put on the positron detector made of a drift chamber,
partially immersed in a magnetic field. The enhancement in photon and positron
production in the aligned crystal have been observed in the energy range 5 to
40 GeV, for the incident electrons, in crystals of 4 and 8 mm as in an hybrid
target. The first results concerning this experiment are presented hereafter.


title: Elliptical X-Ray Spot Measurement

abstract:
  The so-called roll bar measurement uses a heavy metal material, optically
thick to x-rays, to form a shadow of the x-ray origination spot. This spot is
where an energetic electron beam interacts with a high Z target. The material
(the "roll bar") is slightly curved to avoid alignment problems. The roll bar
is constructed and positioned so that the x-rays are shadowed in the horizontal
and vertical directions, so information is obtained in two dimensions. If a
beam profile is assumed (or measured by other means), the equivalent x-ray spot
size can be calculated from the x-ray shadow cast by the roll bar. Thus the
ellipticity of the beam can be calculated, assuming the ellipse of the x-ray
spot is aligned with the roll bar. The data is recorded using a scintillator
and gated camera. Data will be presented from measurements using the ETA II
induction LINAC. The accuracy of the measurement is checked using small
elliptical targets.


title:
High-intensity single-bunch electron beam generation with the 38 MeV
  L-band linac in Osaka University

abstract:
  The characteristics of the high-intensity single-bunch electron beam of the
38 MeV L-band electron linac at the Institute of Scientific and Industrial
Research in Osaka University were investigated.


title: The effects of the rotation in plasma

abstract:
  Electric and magnetic self-fields can exist in the rotating plasma. A
self-sustained rotation can be established in the plasma. The disturbed
distribution function of rotating plasma is derived from the Vlasov equation.
The propagation of waves in rotating plasma differs from that in the usual
plasma. New terms for Landau damping appear. The local rotational behaviour may
become prevailing.


title: The RF source of the 60-MeV Linac for the KEK/JAERI Joint Project

abstract:
  The construction of the 60-MeV proton linac has started as a low-energy front
of the KEK/JAERI Joint Project for a high-intensity proton accelerator facility
at KEK. The accelerating frequency is 324 MHz. Five UHF klystrons are used as
an rf source; their ratings have a maximum power of 3 MW, a beam pulse width of
a 700 micro-sec (an rf pulse width is 650 micro-sec) and a repetition rate of
50 pps. We have manufactured a proto-type rf source (a power-supply system with
a modulating-anode pulse modulator and prototype klystrons). In this paper, the
specifications and developments of the rf source, including the WR-2300
waveguide system, are summarized. During the manufacturing process, strong
oscillations due to back-going electrons from the collector were observed. This
phenomenon was analyzed both experimentally and theoretically. We have tested
up to an output power of nearly 3 MW, and succeeded to test the DTL hot-model
structure.


title:
High-Brightness Beams from a Light Source Injector: The Advanced Photon
  Source Low-Energy Undulator Test Line Linac

abstract:
  The use of existing linacs, and in particular light source injectors, for
free-electron laser (FEL) experiments is becoming more common due to the desire
to test FELs at ever shorter wavelengths. The high-brightness, high-current
beams required by high-gain FELs impose technical specifications that most
existing linacs were not designed to meet. Moreover, the need for specialized
diagnostics, especially shot-to-shot data acquisition, demands substantial
modification and upgrade of conventional linacs. Improvements have been made to
the Advanced Photon Source (APS) injector linac in order to produce and
characterize high-brightness beams. Specifically, effort has been directed at
generating beams suitable for use in the low-energy undulator test line (LEUTL)
FEL in support of fourth-generation light source research. The enhancements to
the linac technical and diagnostic capabilities that allowed for self-amplified
spontaneous emission (SASE) operation of the FEL at 530 nm are described.
Recent results, including details on technical systems improvements and
electron beam measurement techniques, will be discussed. The linac is capable
of accelerating beams to over 650 MeV. The nominal FEL beam parameters used are
as follows: 217 MeV energy; 0.1-0.2% rms energy spread; 4-8 um normalized rms
emittance; 80-120 A peak current from a 0.2-0.7 nC charge at a 2-7 ps FWHM
bunch.


title: The Flat Beam Experiment at the FNAL Photoinjector

abstract:
  A technique for production of an electron beam with a high transverse
emittance ratio. a "flat" beam, has been proposed by Brinkmann, Derbenev, and
Floettmann.[1] The cathode of an RF-laser gun is immersed in a solenoidal
magnetic field; as a result the beam emitted from a round laser spot has a net
angular momentum. Subsequent passage through a quadrupole channel that has a 90
degree difference in phase advance between the transverse degrees of freedom
results in a flat beam. Experimental study is underway at the Fermilab A0
Photoinjector. Thus far, transverse emittance ratios as high as 50 have been
observed, and the results are in substantial agreement with simulation.
  [1] R. Brinkmann, Ya. Derbenev, K. Floettmann, "A Flat Beam Electron Source
for Linear Colliders." TESLA Note 99-09, April 1999.


title: Multiscale Analysis of RMS Envelope Dynamics

abstract:
  We present applications of variational -- wavelet approach to different forms
of nonlinear (rational) rms envelope equations. We have the representation for
beam bunch oscillations as a multiresolution (multiscales) expansion in the
base of compactly supported wavelet bases.

categories: physics.acc-ph math-ph math.MP nlin.CD physics.comp-ph


title: DFQ--Double Frequency RFQ

abstract:
  RFQ with a harmonic higher order quadrupole mode is studied. Assuming that we
superpose a higher order mode with twice the frequency of the fundamental mode,
a sawtooth waveform is approximated. In such a case, the bunching function is
enhanced while the transverse stability is modified. Second order longitudinal
harmonic component is also required to enable the effect.


title: Multiresolution Representation for Orbital Dynamics in Multipolar Fields

abstract:
  We present the applications of variation -- wavelet analysis to
polynomial/rational approximations for orbital motion in transverse plane for a
single particle in a circular magnetic lattice in case when we take into
account multipolar expansion up to an arbitrary finite number and additional
kick terms. We reduce initial dynamical problem to the finite number (equal to
the number of n-poles) of standard algebraical problems. We have the solution
as a multiresolution (multiscales) expansion in the base of compactly supported
wavelet basis.

categories: physics.acc-ph math-ph math.MP nlin.PS physics.comp-ph


title: Nonlinear Beam Dynamics and Effects of Wigglers

abstract:
  We present the applications of variational--wavelet approach for the
analytical/numerical treatment of the effects of insertion devices on beam
dynamics. We investigate the dynamical models which have polynomial
nonlinearities and variable coefficients. We construct the corresponding
wavelet representation for wigglers and undulator magnets.

categories: physics.acc-ph math-ph math.MP nlin.AO physics.comp-ph


title: Spin-Orbital Motion: Symmetry and Dynamics

abstract:
  We present the applications of variational--wavelet approach to nonlinear
(rational) model for spin-orbital motion: orbital dynamics and Thomas-BMT
equations for classical spin vector. We represent the solution of this
dynamical system in framework of periodical wavelets via variational approach
and multiresolution.


title: Local Analysis of Nonlinear RMS Envelope Dynamics

abstract:
  We present applications of variational -- wavelet approach to nonlinear
(rational) rms envelope dynamics. We have the solution as a multiresolution
(multiscales) expansion in the base of compactly supported wavelet basis.


title:
Multiscale Representations for Solutions of Vlasov-Maxwell Equations for
  Intense Beam Propagation

abstract:
  We present the applications of variational--wavelet approach for computing
multiresolution/multiscale representation for solution of some approximations
of Vlasov-Maxwell equations.


title: Quasiclassical Calculations in Beam Dynamics

abstract:
  We present some applications of general harmonic/wavelet analysis approach
(generalized coherent states, wavelet packets) to numerical/analytical
calculations in (nonlinear) quasiclassical/quantum beam dynamics problems.
(Naive) deformation quantization, multiresolution representations and Wigner
transform are the key points.


title:
Some possibilities for laboratory searches for variations of fundamental
  constants

abstract:
  We consider different options for the search for possible variations of the
fundamental constants. We give a brief overview of the results obtained with
several methods. We discuss their advantages and disadvantages with respect to
simultaneous variations of all constants in both time and space in the range
10^{8}-10^{10} yr. We also suggest a few possibilities for the laboratory
search. Particularly, we propose some experiments with the hyperfine structure
of hydrogen, deuterium and ytterbium-171 and of some atoms with a small
magnetic moment. Other suggestions are for some measurements of the fine
structure associated with the ground state. Special attention is paid to the
interpretation of the hfs measurements in terms of variations of the
fundamental constants.


title:
Design of a 3 GHz Accelerator Structure for the CLIC Test Facility (CTF
  3) Drive Beam

abstract:
  For the CLIC two-beam scheme, a high-current, long-pulse drive beam is
required for RF power generation. Taking advantage of the 3 GHz klystrons
available at the LEP injector once LEP stops, a 180 MeV electron accelerator is
being constructed for a nominal beam current of 3.5 A and 1.5 microsecond pulse
length. The high current requires highly effective suppression of dipolar
wakes. Two concepts are investigated for the accelerating structure design: the
"Tapered Damped Structure" developed for the CLIC main beam, and the "Slotted
Iris - Constant Aperture" structure. Both use 4 SiC loads per cell for
effective higher-order mode damping. A full-size prototype of the TDS structure
has been built and tested successfully at full power. A first prototype of the
SICA structure is being built.


title: The Physicist's Guide to the Orchestra

abstract:
  An experimental study of strings, woodwinds (organ pipe, flute, clarinet,
saxophone and recorder), and the voice was undertaken to illustrate the basic
principles of sound production in music instruments. The setup used is simple
and consists of common laboratory equipment. Although the canonical examples
(standing wave on a string, in an open and closed pipe) are easily reproduced,
they fail to explain the majority of the measurements. The reasons for these
deviations are outlined and discussed.


title:
Lifetime Testing 700 MHz RF Windows for the Accelerator Production of
  Tritium Program

abstract:
  Radio frequency (RF) windows are historically a point where failure occurs in
input-power couplers for accelerators. To understand more about the reliability
of high power RF windows, lifetime testing was done on 700 MHz coaxial RF
windows for the Low Energy Demonstration Accelerator (LEDA) project of the
Accelerator Production of Tritium (APT) program. The RF windows, made by
Marconi Applied Technologies (formerly EEV), were tested at 800 kW for an
extended period of time. Changes in the reflected power, vacuum, air outlet
temperature, and surface temperature were monitored over time. The results of
the life testing are summarized.


title: Funneling with the Two-Beam RFQ

abstract:
  New high current accelerator facilities like proposed for HIDIF or ESS
require a beam with a high brilliance. These beams can not be produced by a
single pass rf-linac. The increase in brightness in such a driver linac is done
by several funneling stages at low energies, in which two identically bunched
ion beams are combined into a single beam with twice the frequency current and
brightness. Our Two-Beam-RFQ funneling experiment is a setup of two ion
sources, a two beam RFQ, a funnel deflector and beam diagnostic equipment to
demonstrate funneling of ion beams as a model for the first funneling stage of
a HIIF driver. The progress of the funneling experiment and results of
simulations will be presented.


title: Overview of the APT Accelerator Design

abstract:
  The accelerator for the APT Project is a 100 mA CW proton linac with an
output energy of 1030 MeV. A High Energy Beam Transport (HEBT) conveys the beam
to a raster expander, that provides a large rectangular distribution at a
target/blanket (T/B) assembly. Spallation neutrons generated by the proton beam
in the T/B reacts with Helium-3 to produce tritium. The design of the APT linac
is an integrated normal-conducting (NC)/superconducting (SC) proton linac; the
machine architecture has been discussed elsewhere [1]. The NC linac consists of
a 75 keV injector, a 6.7-MeV 350-MHz RFQ (radio frequency quadrupole), a 96-MeV
700-MHz CCDTL (coupled-cavity drift-tube linac), and a 700-MHz CCL
(coupled-cavity linac), with an output energy of 211 MeV. This is followed by a
SC linac, that employs 700-MHz elliptical niobium 5-cell cavities to accelerate
the beam to the final energy. The SC linac has two sections, optimized for beam
velocities of b =0.64 and b =0.82. Each section is made up of cryomodules
containing two, three, or four 5-cell cavities, driven by 1-MW 700-MHz
klystrons. The singlet FODO lattice in the NC linac transitions to a doublet
focusing lattice in the SC linac, with conventional quadrupole magnets in the
warm inter-module spaces. This doublet lattice is continued in the HEBT. An
overview of the current linac design will be presented.


title:
Reconstruction of Initial Beam Conditions at the Exit of the DARHT II
  Accelerator

abstract:
  We consider a technique to determine the initial beam conditions of the DARHT
II Accelerator by measuring the beam size under three different magnetic
transport settings. This may be time gated to resolve the parameters as a
function of time within the 2000 nsec pulse. This technique leads to three
equations in three unknowns with solution giving the accelerator exit beam
radius, tilt and emittance. We find that systematic errors cancel and so are
not a problem in unfolding the initial beam conditions. Random uncorrelated
shot to shot errors can be managed by one of three strategies: 1) make the
transport system optically de-magnifying; 2) average over many individual
shots; or 3) make the random uncorrelated shot to shot errors sufficiently
small. The high power of the DARHT II beam requires that the beam transport
system leading to a radius measuring apparatus be optically magnifying. This
means that the shot to shot random errors must either be made small (less than
about 1%) or that we average each of the three beam radius determinations over
many individual shots.


title: Quantum string field theory and psychophysics

abstract:
  The quantum string field theoretic structure of interactive phenomena is
discussed


title: The Mechanical Design for the Darht-II Downstream Beam Transport Line

abstract:
  This paper describes the mechanical design of the downstream beam transport
line for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT
II) Facility. The DARHT-II project is a collaboration between LANL, LBNL and
LLNL. DARHT II is a 20-MeV, 2000-Amperes, 2-msec linear induction accelerator
designed to generate short bursts of x-rays for the purpose of radiographing
dense objects. The down-stream beam transport line is approximately 20-meter
long region extending from the end of the accelerator to the bremsstrahlung
target. Within this proposed transport line there are 15 conventional solenoid,
quadrupole and dipole magnets; as well as several speciality magnets, which
transport and focus the beam to the target and to the beam dumps. There are two
high power beam dumps, which are designed to absorb 80-kJ per pulse during
accelerator start-up and operation. Aspects of the mechanical design of these
elements are presented.


title: Theoretical study of the absorption spectra of the sodium dimer

abstract:
  Absorption of radiation from the sodium dimer molecular states correlating to
Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum
transitions from the singlet X Sigma-g+ state to the first excited singlet A
Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the
first excited triplet b Sigma-g+ and triplet c Pi-g states are studied
quantum-mechanically. Theoretical and experimental data are used to
characterize the molecular properties taking advantage of knowledge recently
obtained from ab initio calculations, spectroscopy, and ultra-cold atom
collision studies. The quantum-mechanical calculations are carried out for
temperatures in the range from 500 to 3000 K and are compared with previous
calculations and measurements where available.


title:
Production And Studies Of Photocathodes For High Intensity Electron
  Beams

abstract:
  For short, high-intensity electron bunches, alkali-tellurides have proved to
be a reliable photo-cathode material. Measurements of lifetimes in an RF gun of
the CLIC Test Facility II at field strengths greater than 100 MV/m are
presented. Before and after using them in this gun, the spectral response of
the Cs-Te and Rb-Te cathodes were determined with the help of an optical
parametric oscillator. The behaviour of both materials can be described by
Spicer's 3-step model. Whereas during the use the threshold for photo-emission
in Cs-Te was shifted to higher photon energies, that of Rb-Te did not change.
Our latest investigations on the stoichiometric ratio of the components are
shown. The preparation of the photo-cathodes was monitored with 320 nm
wavelength light, with the aim of improving the measurement sensitivity. The
latest results on the protection of Cs-Te cathode surfaces with CsBr against
pollution are summarized. New investigations on high mean current production
are presented.


title: A "hybrid"-type system for an achromatic focusing of ions

abstract:
  It is known, that at high energies of ions (more than 10 MeV for light ions)
the focusing by magnetic quadrupole fields is most effective, whereas at small
energies (less than 1 MeV) - the focusing by electrical quadrupole fields. At
intermediate energies of ions (from 1 to 10 MeV) the efficiency of each of
these types of a focusing is reduced. The authors offer to utilize for this
purpose the "hybrid" type of focusing systems consisting of sequence of
electrical and magnetic quadrupole lenses, which are localized in the same
space. For making fields of electrical quadrupole lenses it is offered to
utilize RF quadrupoles. The RF electrical quadrupoles are created due to the
relevant configuration of drift tubes in the vicinity of an accelerating gap.
As a result of the general theoretical analysis and calculation of concrete
versions of practical realizations it is shown that the given system has
advantage as contrasted to by known analogs in the field of medium energies.
The velocity band of ions, in which the stable motion is ensured, is
essentially changed, and the focusing becomes "achromatic". The calculations
have been performed for protons with velocities 0.5-1.0 % of light velocity, at
the gradients of electrical field up to 50 kV per square cm, and the gradients
of magnetic field up to 1 T/m. Achromaticity of this system allows to lower a
radiative activation of accelerator and to reduce damage of electrode surfaces
by lost ions.


title: Fractal Statistics

abstract:
  We consider the recent description of elementary particles in terms of
Quantum Mechanical Kerr-Newman Black Holes, a description which provides a
rationale for and at the same time reconciles the Bohm-hydrodynamical
formulation on the one hand and the Nelsonian stochastiic formulation on the
other. The Boson-Fermion divide is discussed, and it is pointed out that in
special situations, anomalous statistics, rather than Bose-Einstein or
Fermi-Dirac states, can be encountered.


title: CLIC, a Two-Beam Multi-TeV e+e- Linear Collider

abstract:
  The CLIC study of a high-energy (0.5 - 5 TeV), high-luminosity (1034 - 1035
cm-2 sec-1) e+e- linear collider is presented. Beam acceleration using high
frequency (30 GHz) normal-conducting structures operating at high accelerating
fields (150 MV/m) significantly reduces the length and, in consequence, the
cost of the linac. Using parameters derived from general scaling laws for
linear colliders, the beam stability is shown to be similar to lower frequency
designs in spite of the strong wake-field dependency on frequency. A new
cost-effective and efficient drive beam generation scheme for RF power
production by the so-called "Two-Beam Acceleration" method is described. It
uses a thermionic gun and a fully-loaded normal-conducting linac operating at
low frequency (937 MHz) to generate and accelerate the drive beam bunches, and
RF multiplication by funnelling in compressor rings to produce the desired
bunch structure. Recent 30 GHz hardware developments and CLIC Test Facility
(CTF) results are described.


title:
Phase Rotation, Cooling And Acceleration Of Muon Beams: A Comparison Of
  Different Approaches

abstract:
  Experimental and theoretical activities are underway at CERN with the aim of
examining the feasibility of a very-high-flux neutrino source. In the present
scheme, a high-power proton beam (some 4 MW) bombards a target where pions are
produced. The pions are collected and decay to muons under controlled optical
condition. The muons are cooled and accelerated to a final energy of 50 GeV
before being injected into a decay ring where they decay under well-defined
conditions of energy and emittance.
  We present the most challenging parts of the whole scenario, the muon
capture, the ionisation-cooling and the first stage of the muon acceleration.
Different schemes, their performance and the technical challenges are compared.


title: Superconducting H-mode Structures for Medium Energy Beams

abstract:
  Room temperature IH-type drift tube structures are used at different places
now for the acceleration of ions with mass over charge ratios up to 65 and
velocities between 0.016 c and 0.1 c. These structures have a high shunt
impedance and allow the acceleration of very intense beams at high accelerating
gradients. The overall power consumption of room temperature IH-mode structures
is comparable with superconducting (sc) structures up to 2 MeV/u. With the
KONUS [1] beam dynamics, the required transversal focusing elements, e.g.
quadrupole triplets can be placed outside of multicell cavities, which is
favourable for building sc H-mode cavities. The design principles and
consequences to the geometry compared to room temperature (rt) cavities will be
described. The results gained from numerical simulations show that a sc
multi-gap H21(0)-mode cavity (CH-type) can be an alternative to the sc
spoke-type or reentrant cavity structures up to beam energies around 150 MeV/u.
The main cavity parameters and possible fabrication options will be discussed.
  [1] U. Ratzinger, Nucl. Intr. Meth., A 415 (1998) 229.


title: An injector for the CLIC test Facility (CTF3)

abstract:
  The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the
technical feasibility of the key concepts of the new RF power source for CLIC.
CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5
A) to 380 MeV (with low current). The injector is based on a thermionic gun
followed by a classical bunching system embedded in a long solenoidal field. As
an alternative, an RF photo-injector is also being studied. The beam dynamics
studies on how to reach the stringent beam parameters at the exit of the
injector are presented. Simulations performed with the EGUN code showed that a
current of 7 A can be obtained with an emittance less than 10 mm.mrad at the
gun exit. PARMELA results are presented and compared to the requested beam
performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to
switch the phase of the bunch trains by 180 degrees from even to odd RF
buckets. Specific issues of the thermionic gun and of the SHB with fast phase
switch are discussed.


title:
Pulsed Neutron Source using 100-MeV electron Linac at Pohang Accelerator
  Laboratory

abstract:
  The Pohang Accelerator Laboratory operates an electron linac for the pulsed
neutron source as one of the long-term nuclear R&D programs at the Korea Atomic
Energy Research Institute. The designed beam parameters are as follows; The
nominal beam energy is 100 MeV, the maximum beam power is 10 kW, and the beam
current is varied from 300 mA to 5A depends on the pulse repetition. The linac
has two operating modes: one for short pulse modes with the various repetitions
between 2 ns and 100 ns and the other for long pulse modes with 1 ms
repetition. We have constructed and tested an electron linac based on the
existing equipment such as a SLAC-5045 klystron, two constant gradient
accelerating sections, and a thermionic RF-gun. We present the characteristics
of the linac and report the status of the pulsed neutron source facilities
include a target system and time-of-flight paths.


title:
Collector Failures on 350 MHz, 1.2 MW CW Klystrons at the Low Energy
  Demonstration Accelerator (LEDA)

abstract:
  We are currently operating the front end of the accelerator production of
tritium (APT) accelerator, a 7 MeV radio frequency quadrapole (RFQ) using
three, 1.2 MW CW klystrons. These klystrons are required and designed to
dissipate the full beam power in the collector. The klystrons have less than
1500 operational hours. One collector has failed and all collectors are
damaged. This paper will discuss the damage and the difficulties in diagnosing
the cause. The collector did not critically fail. Tube operation was still
possible and the klystron operated up to 70% of full beam power with excellent
vacuum. The indication that finally led us to the collector failure was
variable emission. This information will be discussed. A hydrophonic system was
implemented to diagnose collector heating. The collectors are designed to allow
for mixed-phase cooling and with the hydrophonic test equipment we are able to
observe: normal, single-phase cooling, mixed-phase cooling, and a hard boil.
These data will be presented. The worst case beam profile from a collector
heating standpoint is presented. The paper will also discuss the steps taken to
halt the collector damage on the remaining 350 MHz klystrons and design changes
that are being implemented to correct the problem.


title: The Spallation Neutron Source (SNS) Linac RF System

abstract:
  The SNS linac accelerates an average beam current of 2 mA to an energy of 968
MeV. The linac is pulsed at 60 Hz with an H- beam pulse of 1 ms. The first 185
Mev of the linac uses normal conducting cavities, and the remaining length of
the linac uses superconducting cavities. The linac operates at 402.5 MHz up to
87 MeV and then changes to 805 MHz for the remainder. This paper gives an
overview of the Linac RF system. The overview includes a description and
configuration of the high power RF components, the HV converter/modulator, and
the RF controls. Issues and tradeoffs in the RF system will be discussed,
especially with regards to the use of pulsed superconducting cavities.


title:
Beam Emittance Measurements for the Low-Energy Demonstration Accelerator
  Radio-Frequency Quadrupole

abstract:
  The Low-Energy Demonstration Accelerator (LEDA) radio-frequency quadrupole
(RFQ) is a 100% duty factor (CW) linac that delivers >100 mA of H+ beam at 6.7
MeV. The 8-m-long, 350-MHz RFQ structure accelerates a dc, 75-keV, 110-mA H+
beam from the LEDA injector with >90% transmission. LEDA [1,2] consists of a
75-keV proton injector, 6.7-MeV, 350-MHz CW RFQ with associated high-power and
low-level rf systems, a short high-energy beam transport (HEBT) and high-power
(670-kW CW) beam stop. The beam emittance is inferred from wire scanner
measurements of the beam profile at a single location in the HEBT. The beam
profile is measured as a function of the magnetic field gradient in one of the
HEBT quadrupoles. As the gradient is changed the spot size passes through a
transverse waist. Measurements are presented for peak currents between 25 and
100 mA.


title: New Developments in Linear Colliders Final Focus Systems

abstract:
  The length, complexity and cost of the present Final Focus designs for linear
colliders grows very quickly with the beam energy. In the paper, a novel final
focus system is presented and compared with the one proposed for NLC. This new
design is simpler, shorter and cheaper, with comparable bandwidth, tolerances
and tunability. Moreover, the length scales slower than linearly with energy
allowing for a more flexible design which is applicable over a much larger
energy range.


title: CCT, a Code to Automate the Design of Coupled Cavities

abstract:
  The CCT (Coupled Cavity Tuning) code automates the RF calculations and sizing
of RF cavities for the CCL (Coupled Cavity Linac) structures of APT. It is
planned to extend the code to the CCDTL (Coupled Cavity Drift Tube Linac). The
CCT code controls the CCLFISH code, a member of the Poisson Superfish series of
codes [1]. CCLFISH performs RF calculations and tunes the geometry of
individual cavities, including an accelerating cavity (AC) and a coupling
cavity (CC). CCT also relates the AC and CC by means of equations that describe
the coupling slot between cavities. These equations account for the direct
coupling, the next nearest neighbor coupling between adjacent AC's, and the
frequency shifts in the AC and CC caused by the slot. Given design objectives
of a coupling coefficient k, the pi/2 mode frequency, and the net frequency of
the CC, the CCT code iterates to solve for the geometry of the AC and CC and
the separation distance between them (this controls the slot size), satisfying
the design objectives. The resulting geometry is used to automate CAD drawing
preparation. The code can also be used in "as-designed" mode to calculate the
frequencies and coupling of a specified configuration. An overview of the code
is presented.


title: High-Power Testing of the APT Power Coupler

abstract:
  For the baseline APT (Accelerator Production of Tritium) linac design, power
couplers are required to transmit 210-kW of CW RF power to the superconducting
cavities. These APT couplers operate at 700 MHz, have a coaxial design and an
adjustable coupling to the superconducting cavities. Since May 1999, we have
been testing couplers of this design on a room-temperature test stand. We
completed tests at transmitted-power and reflected-power conditions up to 1 MW.
We also tested the couplers with a portion of the outer conductor cooled by
liquid nitrogen. Under this latter condition, we studied the effects of
condensed gases on coupler performance. The results of these tests indicate
that the APT couplers are capable of delivering more than 500 kW to the
cavities. We are in the process of increasing the baseline coupler design
requirement to 420 kW of transmitted power to take advantage of this successful
development. In this paper, we describe the results of our high-power coupler
tests.


title: Possibility of a Light Pulse with Speed Greater than c

abstract:
  In two models it is shown that a light pulse propagates from a vacuum into
certain media with velocity greater than that of a light in a vacuum (c). By
numerical calculation the propagating properties of such a light are given.


title: Energy focusing inside a dynamical cavity

abstract:
  We study the exact classical solutions for a real scalar field inside a
cavity with a wall whose motion is self-consistently determined by the pressure
of the field itself. We find that, regardless of the system parameters, the
long-time solution always becomes nonadiabatic and the field's energy
concentrates into narrow peaks, which we explain by means of a simple
mechanical system. We point out implications for the quantized theory.


title:
Annealing of radiation induced defects in silicon in a simplified
  phenomenological model

abstract:
  The concentration of primary radiation induced defects has been previously
estimated considering both the explicit mechanisms of the primary interaction
between the incoming particle and the nuclei of the semiconductor lattice, and
the recoil energy partition between ionisation and displacements, in the frame
of the Lindhard theory. The primary displacement defects are vacancies and
interstitials, that are essentially unstable in silicon. They interact via
migration, recombination, annihilation or produce other defects. In the present
work, the time evolution of the concentration of defects induced by pions in
medium and high resistivity silicon for detectors is modelled, after
irradiation. In some approximations, the differential equations representing
the time evolution processes could be decoupled. The theoretical equations so
obtained are solved analytically in some particular cases, with one free
parameter, for a wide range of particle fluences and/or for a wide energy range
of the incident particles, for different temperatures; the corresponding
stationary solutions are also presented.


title: Latest Developments from the S-DALINAC*

abstract:
  The S-DALINAC is a 130 MeV superconducting recirculating electron accelerator
serving several nuclear and radiation physics experiments as well as driving an
infrared free-electron laser. A system of normal conducting rf resonators for
noninvasive beam position and current measurement was established. For the
measurement of gamma-radiation inside the accelerator cave a system of Compton
diodes has been developed and tested. Detailed investigations of the transverse
phasespace were carried out with a tomographical reconstruction method of
optical transition radiation spots. The method can be applied also to
non-Gaussian phasespace distributions. The results are in good accordance with
simulations. To improve the quality factor of the superconducting 3 GHz
cavities, an external 2K testcryostat was commissioned. The influence of
electro-chemical polishing and magnetic shielding is currently under
investigation. A digital rf-feedback-system for the accelerator cavities is
being developed in order to improve the energy spread of the beam of the
S-DALINAC.
  * Supported by the BMBF under contract no. 06 DA 820, the DFG under contract
no. Ri 242/12-1 and -2 and the DFG Graduiertenkolleg 'Physik und Technik von
Beschleunigern'


title: Linac Lue200. First Testing Results

abstract:
  "LUE200" - 200 MeV electron linac is being created at JINR as a driver of the
pulsed neutron source "IREN" [1]. The special full-scale facilities for testing
the main systems of LUE-200 (FSTF) are used at JINR, BINP, MEPhI and YerPhI
[2]. The verification of the linac accelerating system is providing at the
VEPP-5 preinjector constructed at BINP [3]. The accelerating system of LUE200
includes two S-band (2856 MHz) accelerating sections of 3 m long. The sections
are connected with modulator based one 5045 klystron (SLAC production). There
are SLED-systems for the multiplying the pulse RF power. The first results of
the accelerating system test on the VEPP-5 preinjector are presented. The
electron beam energy up to 92 MeV and consequently average rate of acceleration
of the electron beam more than 30 MeV/m were achieved after acceleration in one
section.


title: A Super-Conducting Linac Injector for the BNL-Ags

abstract:
  This paper reports on the feasibility study of a proton Super-Conducting
Linac (SCL) as a new injector to the Alternating Gradient Synchrotron (AGS) of
the Brookhaven National Laboratory (BNL). The Linac beam energy is in the range
of 1.5 to 2.4 GeV. The Beam intensity is adjusted to provide an average beam
power of 4 MW at the top energy of 24 GeV. The repetition rate of the SCL-AGS
facility is 5 beam pulses per second.


title: A Super-Conducting Linac Driver for the HFBR

abstract:
  This paper reports on the feasibility study of a proton Super-Conducting
Linac (SCL) as a driver gor the High-Flux Breader Reactor (HFBR) at Brookhaven
National Laboratory (BNL). The Linac operates in Continuos Wave (CW) mode to
produce an average 10 MW of beam power. The Linac energy is 1.0 GeV. The
average proton beam intensity is 10 mA.


title: On the Confidence Interval for the parameter of Poisson Distribution

abstract:
  The possibility of construction of continuous analogue of Poisson
distribution with the search of bounds of confidence intervals for parameter of
Poisson distribution is discussed. Also, in the article is shown that the true
value of a parameter of Poisson distribution for the observed value $\hat x$
has Gamma distribution with the scale parameter, which is equal to one, and the
shape parameter, which is equal to $\hat x$. The results of numerical
construction of confidence intervals are presented.


title: Theory of nuclear spin conversion in ethylene

abstract:
  First theoretical analysis of the nuclear spin conversion in ethylene
molecules (13^CCH4) has been performed. The conversion rate was found equal
approx. 3x10^{-4} 1/s*Torr, which is in qualitative agreement with the recently
obtained experimental value. It was shown that the ortho-para mixing in 13^CCH4
is dominated by the spin-rotation coupling. Mixing of only two pairs of
ortho-para levels were found to contribute significantly to the spin
conversion.


title: Wire Scanners for Small Emittance Beam Measurement in Atf

abstract:
  The wire scanners are used for a measurement of the very small beam size and
the emittance in Accelerator Test Facility (ATF). They are installed in the
extraction beam line of ATF damping ring. The extracted beam emittance are
ex=1.3x10-9 m.rad, ey=1.7x10-11 m.rad with 2x109 electrons/bunch intensity and
1.3GeV energy. The wire scanners scan the beam by a tungsten wire with beam
repetition 0.78Hz. The scanning speed is, however, very slow(~500um/sec). Since
the extracted beam is quite stable by using the double kicker system, precision
of the size measurement is less than 2um for 50 - 150um horizontal beam size
and 0.3um for 8 - 16um vertical beam size. The detail of the system and the
performance are described.