Layers for ion beam energy conversion into black body radiation

Abstract

The radiation hydrodynamics of material layers for energy conversion of intense ion beams into black body radiation is investigated, both analytically and numerically. Conversion efficiency and hydrodynamic losses are the main topics. The basic scaling relations are derived and compared with computer simulations. Although the analysis is done for slab geometry, a generalization to converters of arbitrary shape and deposition geometry is outlined. The code MINIRA is briefly described. The influence of varying layer density, optical thickness and beam power on radiation emission as well as the effect of Bragg peak deposition are discussed in detail. High conversion efficiencies of more than 50% can be obtained provided that the converter is operated in the radiative regime. For typical beam intensities, this requires low-density layers. Another essential feature is supersonic heat transport which occurs in the radiative regime.