Calibration system for satellite and rocket-borne ion mass spectrometers in the energy range from 5 eV/charge to 100 keV/charge

A system has been designed for testing and calibrating satellite-borne ion mass spectrometers which provides a large-area (250 sq cm), highly parallel, and spatially uniform beam of ions over the range from 5 eV/charge to 100 keV/charge. The system features variable energy spread from 1 eV/charge to 3 keV/charge and multiple charge state ions such as He(2+) or Xe(9+). The system incorporates a high-efficiency electron bombardment ion source capable of delivering about 10 to the -8th A, a 90-deg crossed electric and magnetic field mass spectrometer designed to produce either a mixed or mass-selected beam, and a beam expansion system which produces the uniform large-area beam. The system includes automatic beam monitoring and control via a feedback loop, as well as provisions for semiautomatic control of angle and energy analysis. Calibration results for a GEOS satellite are presented.