Evidences of accumulation points in cascade regenerative phenomena observed in high voltage dc devices insulated by long vacuum gaps

Localized heating has been observed in unexpected positions on anodic surfaces in a multi-electrode
device insulated by vacuum gaps. In double polarity experiments, a counter-intuitive behavior of
current-voltage characteristic has also been observed. The phenomena could depend on a cascade
effect of charged particles exchanged between electrodes and on a mutual correlation of particle
trajectories between electrode surfaces occurring during the high voltage conditioning phase.
Attractors regions ascribed to regenerative processes of charged particles between cathode and anode
have been identi
fi
ed thanks to numerical simulations The position of the attractors depends only on
electrode shape and the ratios of applied voltages. This
fi
nding suggests new perspectives in neutrons
sources applications, where recurrent impacts of focused high energy hydrogen isotopes take place on
solid hydride targets supported by metallic electrodes insulated by vacuum gaps.