Evaluation of an elliptical grid mirror electrostatic analyzer for space applications

We report on our investigation into the development of electrostatic mirror based charged particle analyzers for space plasma physics experimentation. For this work, we tested an elliptical mirror analyzer which was designed to provide a wide, 2-dimensional field of view with high throughput and good angular resolution. Measurements with an ion beam demonstrated 2 degrees full width at half-maximum angular resolution over a 16x16 degrees field of view (FOV) and 4 degrees resolution over a 40x40 degrees FOV for an optical system with a linear dimension (entrance aperture to the particle detector) of 20 cm. The energy resolution is variable, similar in operation to a retarding-potential-analyzer or a modulated grid Faraday cup, with a geometric factor of 3.2x10(-3) cm(2) str Delta E/E for an energy resolution setting of 10%. (C) 1997 American Institute of Physics.