Single-pulse electrons from a linear accelerator

The electronic circuits of a 35 MeV linear accelerator at Hiroshima University were modified to produce single-pulse electrons. Single-pulse electrons were obtained by synchronizing one of eight pulses from an electron gun modulator, 120 pps, to one of the micro-waves from a klystron, 15 pps. After single-pulse electrons were discharged, a signal was relayed to a stop-gate circuit from a binary scaler which was connected to the gun modulator. Although reproducibility of single-pulse electrons and stability of electron output per pulse were not completely satisfactory, it was possible to use for radiobiological studies. Biological effects of single-pulse electrons (energy: 25 MeV, dose rate: 1010 rad/min) on cultured mammalian cells and on mice were nearly equal to those of multi-pulse electrons (25 MeV, 107 rad/min) and Co-60 γ-rays (dose rate: 100 rad/min). (auth.)