Calculations have been made to determine the voltage surge amplitudes in the stack of Van de Graaff generators subsequent to the breakdowns between the equipotential rings and the earthed tank. The presented formulae include the case of breakdowns between the high voltage terminal and the earthed tank, too. The results show considerable effect of the sparkovers between some equipotential rings in the vicinity of the terminal and the earthed tank on the voltage surges. The application of surplus capacitances suggested earlier decreases the voltage surge amplitudes. However what seems to be the most effective solution is to shield these equipotential rings by using special electrode configuration proposed as optimum shape with respect to static field distribution.
ASJC Scopus subject areas