CHARACTERISTICS OF ELECTRON MULTIPLIERS USED AS DETECTORS FOR LOW ENERGY PROTONS

Windowless electron multipliers present a detection efficiency close to 90% for protons and for He+ ions above 2 keV. The proper polarization of the entrance of the detector enables one to preserve this efficiency with much lower energies. These detectors do not allow for direct spectrometry; it is necessary to join to them an electrostatic analysis. This type of analysis has been experimentally and theoretically developed for the study of the spectrum and of the angular distribution of auroral protons from 100 eV to 40 keV. © 1969.