Studies of atmospheric albedo neutrons and gamma rays with cgro/comptel we propose to comprehensively analyze earth albedo neutron and gamma data from the comptel experiment on the compton observatory…

This $258,982.40 federal grant award, issued by the National Aeronautics and Space Administration (NASA), supports the University of New Hampshire (UNH) in conducting a comprehensive analysis of Earth albedo neutron and gamma data collected by the COMPTEL experiment on the Compton Gamma Ray Observatory spacecraft between 1991-2000. The data covers the energy range of 15-150 MeV neutrons and 0.8-30 MeV gamma rays, which are relevant for modeling the dynamics of the inner radiation belt. This work is seen as valuable in calibrating radiation belt models, as the COMPTEL data provides observations spanning a full solar cycle and a wide geographic range not captured by other single-point measurements. No set-aside was used for this grant award. UNH, a non-profit land grant university, has experience providing research, technical assistance, and education services to federal agencies across a range of disciplines.

Studies of atmospheric albedo neutrons and gamma rays with cgro/comptel we propose to comprehensively analyze earth albedo neutron and gamma data from the comptel experiment on the compton observatory (cgro), which operated on orbit from 1991 2000. Comptel was sensitive to 15 150 MEV neutrons and 0.8 30 MEV gamma rays. Neutrons in this energy range are largely responsible for populating the inner belt with high energy protons. The instrument spent considerable time looking downward during its nine years of astrophysical observations. Few albedo neutrons measurements exist that can be used to calibrate the radiation belt models that describe the dynamics of the trapped radiation. Those observations occurred at single points on the globe and for brief moments in time, whereas we know that secondary radiation, even at ground level, varies considerably over the solar cycle and from episodic heliospheric events. These data have languished since the demise of the cgro mission, primarily from the difficulties of characterizing the instrument as IT responds to neutrons. Modern simulation tools (e.g., GEANT4) are now far more capable of simulating the neutron response and with the timely interest in the radiation belts, as epitomized by the van allen mission, these data deserve study. They cover the appropriate energy range for the inner belt proton spectrum, they span a full solar cycle, and they cover a geographic latitude range of 28? Or a maximum l shell of 1.7, in good agreement with the inner belt coordinates.