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. Particle spectra and dependences of fluences on primary energy (1–250 GeV), on angle (20–150°) and on target mass number are given, together with the total number of low-energy neutrons and of high-energy neutrons per electron. The attenuation of the total hadron dose equivalent in concrete and dose ratios of the main components are calculated. All results are parametrized and expressed by simple formulae. In addition, the hadron field behind copper and lead absorbers (beam shutters) in beam direction, its composition and its dependence on primary energy (1–50 GeV), on distance, and on absorber type are studied. Again the total hadron dose equivalent can be expressed by a simple equation. The dose attenuation by an additional concrete shield behind an absorber is examined