Calibration of two compact permanent magnet spectrometers for high current electron linear induction accelerators

In this work, two compact, permanent magnet, electron spectrometers have been built to measure the electron beam energy at the Dual Axis Radiographic Hydrodynamic Test facility. Using H− and OH− anions, the spectrometers were calibrated at the Special Technologies Laboratory in Santa Barbara, California (USA). The spectrometers were mounted on a custom drift tube that allows the magnet assemblies to be translated, which increases the path length of the electrons traveling through the magnetic field and therefore increases the upper bound of the measurable electron kinetic energy. The measurable range of electron kinetic energies is between 2.8 MeV–4.1 MeV for the first spectrometer and 14.1 MeV–21.1 MeV for the second spectrometer, with an overall measurement uncertainty of 0.32%.