Investigation of Voltage Breakdown in the Vacuum of DC Electrostatic Separator

Abstract

A small rectangular dc electrostatic separator with the dimensions 1×1×2m3 is used to investigate the voltage breakdown in the vacuum of a dc electrostatic separator with the electrodes 400 mm in diameter. The electrodes are made of several materials to which voltages are applied up to 400 kV. The chamber is evacuated to 1×10-6 Torr with a turbo-molecular pump and an ion pump. A gas is fed to the chamber to obtain a curve of maximum voltage as a function of the pressure, a P-V curve. The P-V curves are obtained by varying the kind of gas, the material of the cathode and the gap spacing etc. Speculations are given for the voltage breakdown mechanism in the vacuum of the separator, and condition for the optimization of the design of dc electrostatic separators are also given.

Experimental investigation of an optimum configuration for a high-voltage photoemission gun for operation at≥500 kV

“…Adding gas to a vacuum chamber is known to be an effective method of HV conditioning [19,20]. In an experiment on the 1-MV bushing of the International Thermonuclear Experimental Reactor neutral beam injector at Cadarache in France, HV conditioning up to 973 kV was demonstrated when 2 × 10 −2 Pa of hydrogen or helium gas was added to the chamber [21].…”