THE LARGE GAP CASE FOR HV INSULATION IN VACUUM

A test setup able to accommodate dish shaped electrodes for gaps up to similar to 20 cm is being used to study large gap effects. This exper iment, in connection with other authors' experiments, underlines the t hree more characteristic aspects of the large gap case: a voltage effe ct, a current effect and a gas effect. The difficulty of energy dissip ation by surface processes at increasing penetration depth of the ener gy deposit gives an interesting interpretative perspective to the beha vior of large gap, HV devices.