EVALUATION OF AN ELLIPTIC GRID MIRROR ELECTROSTATIC ANALYZER FOR SPACE APPLICATIONS

We report on our investigation into the development of electrostatic m irror based charged particle analyzers for space plasma physics experi mentation. For this work, we tested an elliptical mirror analyzer whic h was designed to provide a wide, 2-dimensional field of view with hig h throughput and good angular resolution. Measurements with an ion bea m demonstrated 2 degrees full width at half-maximum angular resolution over a 16x16 degrees field of view (FOV) and 4 degrees resolution ove r a 40x40 degrees FOV for an optical system with a linear dimension (e ntrance aperture to the particle detector) of 20 cm. The energy resolu tion is variable, similar in operation to a retarding-potential-analyz er 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) 1 997 American Institute of Physics.