Introduction to general relativity in a setting with comparatively strong gravitational fields. This has become possible thanks to precision observations of binary pulsars. In such a star system, two highly compact neutron stars orbit each other. At least one of them is a pulsar – an astronomical object that emits a tight beam of radiowaves. These beams strike the Earth at very regular intervals, similarly to the way that the rotating beam of a lighthouse means that an observer sees the lighthouse blink, and can be observed as a highly regular series of pulses. General relativity predicts specific deviations from the regularity of these
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