High-energy heavy ion beams in materials science

In many countries, high-energy Tandem accelerators have been quite widely applied in materials science. This is due to two major types of application: (i) Various beam-induced materials modifications based on the enhanced electronic stopping associated with such high-energy heavy ions (for example, fission fragment simulation experiments, flux-pinning of high Tc superconductors, formation of nanometer filter arrays); and (ii) development of heavy-ion elastic recoil detection analysis (ERDA) as a universal analytical probe capable of detecting virtually all elements simultaneously and with almost constant detection sensitivity. Radiation damage effects are often dominant in such applications. Hence, we examine briefly some Thomas-Fermi scaling rules for estimating the approximate magnitude of nuclear and electronic stopping as a function of the energy (E) and atomic number (Z1) of the beam. For the specific case of ERDA, such estimates are used to optimize detector selection as a function of E and Z; they are also combined with recent measurements of beam-induced erosion in various targets in order to show that in many materials the damage per ERDA analysis can often be reduced by using the heaviest available beam. (orig.)