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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Computer processing role in film scanning and digitizing for enhancing X ray and radioisotope scanner images in medical radiographs, discussing image noise reduction
SNAP 19 radioisotope fueled thermoelectric power supply orbital performance on Nimbus 3, ascribing power output decrease to decreasing generator output currents
Apollo 11 lunar rocks and fines cosmic ray produced radioisotopes, considering surface exposure to high energy component flux
Radioisotope thrustors for space propulsion, considering thermal heating methods and direct recoil
Spacecraft radioisotope thermoelectric generator interference in onboard instrument operation, using analytical models to determine necessary shielding
Performance of planar radioisotope thermoelectric generator model
Nimbus 3/SNAP 19 radioisotopic thermoelectric generator design and performance
Radioisotope thermionic power supply for unmanned electric propulsion missions to outer planets, using 69 modules consisting of thermionic converter and emitter heat pipe
Impact resistant power packages for unmanned planetary probe landers, discussing radioisotope thermionic multiconverter array optimal configuration
Integrated waste collection and purification system using radioisotopes for thermal energy in 180-day space mission life support system
Radioisotope thermoelectric generators integration for Pioneer 6/7 program, discussing design requirements
Multihundred watt radioisotope thermoelectric generator for JPL outer planet missions, discussing vacuum/xenon filled performance and response to thermal/electrical transients
Grand tour missions radioisotope thermoelectric generator power source, presenting optimization technique for hot thermocouple junction operation
Radioisotope thermoelectric generator safety and operations considerations for users of large nuclear space power systems
Radioisotopes as energy source for power conversion systems, discussing future availability of fission products and transuranium elements from commercial nuclear power reactors
Orbital performance of SNAP 19 radioisotopic thermoelectric generator for nuclear power supply on Nimbus 3 observatory
A simulated source was designed to duplicate the gamma spectrum of a uniform cylindrical 2200-watt Pu02 radioisotope thermoelectric generator containing 81% Pu-238 and 1.2 ppm Pu-236. Gamma rays from the decay of Pu-238, Am-241, Pu-239, and the 0-18(alpha,n)Ne-21 reaction were catalogued in broad energy groups. Two 46- and one 22-mc Th-228 sources provided simulation at various times in the life of the fuel capsule up to 18 years, which covers the time span of an outer planet mission. Emission from Th-228 represents the overwhelming contribution of the gamma spectrum after the first few years. The sources, in the form of 13-inch rods, were placed in a concentric hole in a cylinder of depleted uranium, which provided shielding equivalent to the self-shielding of the fuel capsule. The thickness of the U-238 cylinder (0.55cm) was determined by Monte Carlo calculations to insure that the spectrum emerging from the simulated source matched that of the fuel capsule.
A new type of gamma-ray camera is discussed that makes use of electron avalanches in liquid xenon and is currently under development. It is shown that such a radioisotope camera promises many advantages over any other existing gamma-ray cameras. Spatial resolution better than 1 mm and counting rates higher than one million C/sec are possible. An energy resolution of 11% FWHM has recently been achieved with a collimated Hg-203 source using a parallel-plate ionization chamber containing a Frisch grid.