Calculation of hadron yields around thick targets and doses behind concrete shielding of high-energy electron accelerators

The field of neutrons, protons, and pions produced by high-energy electrons hitting thick targets is studied by means of the FLUKA Monte Carlo code. P article spectra and dependences of fluences on primary energy (1-250 GeV), on angle (20-150 degrees) and on target mass number are given, together wit h the total number of low-energy neutrons and of high-energy neutrons per e lectron. The attenuation of the total hadron dose equivalent in concrete an d dose ratios of the main components are calculated. All results are parame trized and expressed by simple formulae. In addition, the hadron field behi nd copper and lead absorbers (beam shutters) in beam direction, its composi tion and its dependence on primary energy (1-50 GeV), on distance, and on a bsorber type are studied. Again the total hadron dose equivalent can be exp ressed by a simple equation. The dose attenuation by an additional concrete shield behind an absorber is examined. (C) 2000 Elsevier Science B.V. All rights reserved.