Low-Energy Electron and Proton Satellite Instrumentation for Auroral Studies

Several instruments employing variable-energy electrostatic thresholds and post-acceleration techniques in conjunction with plastic scintillator-photomultiplier detectors have been successfully used in a satellite experiment to measure low-energy electrons and protons in the auroral regions. A description of these instruments, which were designed to measure electrons in the energy range of 0.015 to 10.0 keV with detection sensitivities as high as 4 x 10-4 erg/cm2-sec-sr and protons in the energy range of 0.20 to 10.0 keV with detection sensitivities of 6 x 10-3erg/cm2-sec-sr, is given. A discussion of the procedures employed in the laboratory calibration of these instruments is presented. In-flight calibration techniques involving both radioactive sources and programmable Ga-P light diodes are also described. The performance of the instruments during two satellite flights in November, 1963, and November, 1965, is illustrated by the presentation of some typical data.