A Particle Spectrometer with a Large Geometric Factor for the Energy Range 0.1 to 30 Kev

摘要

The design and the calibration of a detector using a channel electron multiplier (CEM) together with a spherical electrostatic analyzer are described. The CEM characteristic equivalent energy band widths, opening angles, and sensitive areas are defined and are given as functions of energies between 0.1 to 25 keV. The analyzer deflection high voltage, the CEM acceleration high voltage, the measurement control unit and the data processing interfaces are described. The numerical analysis of the geometric factor from the calibration data is demonstrated. Energy and pitch angle distribution of energetic electrons were measured. The 90 deg sensor detects a constant energy spectrum over the entire period, while the 30 deg sensor exhibits large variations. Changes in trapped particle pitch angle distribution (from isotropic at 154 to 156 sec flight time to anisotropic above 157 sec at the lowest and highest energies) explains the variations.