Voltage Holding Prediction in Multi Electrode-multi Voltage Systems Insulated in Vacuum

The PRIMA Test Facility: SPIDER and MITICA test-beds for ITER neutral beam injectors

“…This research allowed identification of the strategy to perform voltage conditioning in the presence of a magnetic field. Other achievements regard the validation of the Voltage Holding Predictive Model (VHPM), which allows the prediction of the voltage breakdown probability curve for any multivoltage-multielectrode configuration [96,97]. The VHPM has been applied in the design of the MITICA accelerator [58].…”

“…• The Voltage Holding Predictive Model VHPM [96] estimates the breakdown voltage taking into account the effect of the electrode surface and particle trajectories with a probabilistic approach [97].…”

Development of versatile multiaperture negative ion sources

“…An important experimental NIO1 research is the reaction of electronics to possible breakdowns in 60 kV insulation (see also [23]), which is a topic of general interest especially for MITICA [24], also in consideration of long operation time envisioned.…”

Progress in the MITICA beam source design

“…A numerical tool for voltage breakdown prediction of a multi-electrode system insulated by vacuum gaps was developed, based on the implementation of the micro particle (clump) induced breakdown Cranberg-Slivkov theory into a statistical approach defined by Weibull's two parameters distribution. 4 In parallel to design activities, a thorough R&D campaign is being carried out in a dedicated new high voltage test facility, 5 in order to characterize HV holding up to 800 kV, considering different electrodes dimensions, shapes, materials, and surface conditions. The results of electrostatic analyses and breakdown probability estimation (see Figure 4) allowed to identify the critical points for high voltage holding and to improve the design; in the right side of the figure, warmer colors represent the critical clump trajectories 4 where the breakdown can initiate.…”