Stellar rotation can have a very rapid rate of rotation; on the order of a hundred rotations per second. Pulsars are rotating neutron stars that have a magnetic field. A narrow beam of electromagnetic radiation is emitted from the poles of rotating pulsars. If the beam sweeps past the direction of the Solar System then the pulsar will produce a periodic pulse that can be detected from the Earth. The energy radiated by the magnetic field gradually slows down the rotation rate, so that older pulsars can require as long as several seconds between each pulse. A black hole is an object
Ion beam analysis 267(12-13). Ion beam analysis works on the basis that ion-atom interactions are produced by the introduction of ions to the sample being tested. Major interactions result in the emission of products that enable information regarding the number, type, distribution and structural arrangement of atoms to be collected. To use these interactions to determine sample composition a technique must be selected along with irradiation conditions and the detection system that will best isolate the radiation of interest providing the desired sensitivity and detection limits. The basic layout of an ion beam apparatus is an accelerator which produces an ion beam that