A method for measuring electron energy distribution in a plasma focus

A magnetic energy analyzer is designed for pulsed energetic electron beams, and successfully used to obtain energy distribution of the electron beam generated by a plasma focus device. In order to provide quick access of the electron energy distribution in a single shot, an electron detection system consisting of an MCP (microchannel plate) and a PCD (plasma-coupled device) linear image sensor is developed. Sensitivity calibration of the system is carried out using the nuclear emulsion sensitive to energetic electrons. Energy resolution and dynamic range of the detector are presented as functions of the electron energy. The major part of the energy-distributed electrons generated by the plasma focus device are in the relativistic region extending to higher than 1 MeV. The acceleration mechanism of those electrons up to such a huge energy is discussed.