Demonstrate the feasibility of a detection method to separate neutral particles from charged particles in the MeV/vnucleon energy range. Final report, July 1988-December 1989

A breadboard model of a spacecraft borne instrument to measure neutral hydrogen atomic fluxes with energies between 1 to 10 MeV/nucleon has been designed, constructed and tested. Differentiation between incident charged and neutral particles was accomplished by measuring the production rate of convoy electrons by the particles. Convoy electron production rate is much larger for neutral hydrogen than for protons. Incident particles strike a thin carbon foil at the entrance aperture and the resulting convoy electrons are deflected by an applied electrostatic field and detected by a micro channel plate detector. The forward going protons are undeflected by the electric field and are detected in a solid state detector. The instrument has been tested with accelerator proton and atomic hydrogen beams of 1.5 to 4 MeV energy. Experimental results and theoretical model calculations are compared. A design for an improved spacecraft instrument is presented.