Electron avalanches in liquid xenon induced by space charge

Processes of electron multiplication in high electric field created by space charge near a cathode can play an essential role in current flow in matter. In accelerator experiments the results were obtained which can be explained as electron avalanches induced in plain geometry by space charge. Two-electrode plane ionization chamber filled with liquid Xe was irradiated by high intensity pulses of bremsstrahlung. In short time after the start of an irradiation pulse space charge was formed in the chamber. The field strength near a cathode became strong enough to produce electron avalanches in liquid. They were revealed in the changing of a current and voltage pulse form. The threshold for impact ionization in liquid Xe at the temperature 230 K in this work is equal to 9×10⁴ V/cm in contrast to 4 10⁵ V/cm for liquid Xe at the temperature 163 K