A statistical investigation on the breakdown strength of liquid helium with IEC and cylindrical electrodes

To provide data to the designer of high voltage cryogenic apparatuses, a statistical investigation is performed on the breakdown strength of liquid helium. Tests are performed under as controlled as possible conditions, with gaps in the millimeter range, bath with IEC spherical bowl electrodes and cylindrical electrodes. The gap effect and the influence of test conditions are investigated with IEC electrodes, whereas with cylindrical electrodes is performed an analysis of the area effect. The main statistical parameters of the data test sets are calculated and reported, and the obtained results are discussed.