APPLICATIONS OF ACCELERATOR MASS-SPECTROMETRY TO NUCLEAR ASTROPHYSICS

The technique of accelerator mass spectrometry is widely used to perfo rm ultrasensitive measurements of concentrations of rare isotopes in s amples placed in the ion source of the accelerator system. The high se lectivity of high-energy magnetic and electrostatic analyses and the c apabilities of particle identification methods can be equally exploite d when rare isotopes are generated in the system by the interaction of the primary beam with a solid or gaseous target. Slight modifications of an AMS system lay-out allow the measurement of low reaction cross sections of special interest to nuclear astrophysics. A project aiming to provide an improved value for the cross section of the astrophysic ally important reaction Be-7(p, gamma) B-8 is presented and results of a test measurement of the C-12(p, gamma) N-13 reaction, showing the f easibility of the method, are reported. Advantages, limitations and po ssible extensions in the applications of this technique are discussed.