Accession Number : AD0635525

Title :   THE STUDY AND INVESTIGATION OF NEUTRONS PRESENT ABOVE THE ATMOSPHERE IN NEAR-EARTH SPACE.

Descriptive Note : Final rept. 1 Jun 63-31 Jan 66.

Corporate Author : RIAS INC BALTIMORE MD

Personal Author(s) : Martin, J. P. ; Mead,J. B.

Report Date : MAR 1966

Pagination or Media Count : 77

Abstract : The density of neutrons above the atmosphere was measured by a pair of BF3 proportional counter systems aboard a polar orbiting satellite. The shape of the latitude variation of the measured density (10:1 between poles and equator) was consistent with theoretical predictions, but the measured absolute values were about three times higher. Since neutrons in the vicinity of earth are produced by cosmic ray interactions, instrumentation was developed to measure the poorly known heavy element component of the cosmic radiation. A large area scintillator-Cerenkov telescope with a geometric factor of 176 sq cm stearadian was developed in prototype for measurements from high altitude baloons. The principal difficulty in developing a telescope with large aperture (necessary for good counting statistics) is maintaining good pulse height resolution. This was solved for the Cerenkov detector with a technique of optical trimming of the photomultiplier cathods. A number of detection schemes for high energy neutrons were investigated including a proton recoil detector, a C12-3 alpha detector, and bismuth fission detectors. The conclusion of this study is that a compact multiplate fission ionization chamber would be more practical than a bismuth loaded liquid scintillator.

Descriptors :   (*COSMIC RAYS, *NEUTRONS), ALBEDO, SCIENTIFIC SATELLITES, POLAR ORBIT TRAJECTORIES, COSMIC RAY TELESCOPES, SCINTILLATION COUNTERS, BALLOONS, RESOLUTION, NEUTRON DETECTORS, IONIZATION CHAMBERS

Subject Categories : Astrophysics
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE