Monte Carlo simulation of bremsstrahlung spectra for low energy electron accelerators

Four Monte-Carlo codes where tested to simulate bremsstrahlung spectra for accelerated electron beams at the energy range 4-20 MeV. All four codes give the same shape of the spectrum, in which in addition to the bremsstrahlung part there are characteristic energy lines of the target atom and an annihilation line of 0.511 MeV caused by secondary processes of the photoelectric effect and of electron-positron pair production. The absolute values of the energy spectrum have close magnitudes but it requires a more thorough study.