Advances in the efficient generation of intense pulsed proton beams

Abstract

Recent studies on the space−charge−limited reflex vacuum triode pulsed ion accelerator show a marked improvement in the output parameters and efficiency of the device. In the current machine, a 50−nsec pulse of 130−keV protons of 6000 A is produced at a current density of 20 A/cm². Energies up to 300 keV have been investigated. The troide efficiency, defined as proton energy output versus total energy input, has been raised from 10 to 42% by the addition of magnetic fields that prevent anomalous electron loss in the fringing fields at the edges of the electrodes. Time−of−flight measurements confirmed the peak energies. The beam was measured to have about a 10 ° half−angle of spread. The results obtained indicate that the accelerator may be scaled to the ranges of parameters currently achieved by pulsed electron accelerators.