Engineering topics
Publications and source records attributed to Trainor, J. H..
Solid state low-energy telescopic observations on solar and galactic cosmic rays from 2 AU outward by satellites are evaluated. Plots of solar events leading to large injections of particles from the sun show that low energy slower protons arrive first by many hours before the higher energy protons, and that the higher energy particles are falling off more rapidly.
Spacecraft design fluences and damage by low energy electrons and protons are summarized. For electron energies 5 MeV, the design fluence is 10 to the 11th power electrons/sq cm; for energies 5 MeV, the integral spectrum is assumed to go as 1/E sq. The design fluences for proton energies 30 MeV is 1.5 x 10 to the 9th power protons/sq cm; for energies 100 MeV, it is 5 x 10 to the 14th power protons/sq cm. The radioisotope thermoelectric generator gamma and neutron radiation constraints are listed. Damage due to electron energies 0.5 MeV and proton energies 10 MeV are summarized for effects on spacecraft thermal surfaces, reflective surfaces, and refractive materials. The high frequency noise figure for field effect transistors may increase markedly, and another effect is the buildup of charge on insulating surfaces, resulting in large electric fields.
Continuing development and expansion of a series of P-channel MOSFET circuits in flight data systems is reported. Using hybrid thick film techniques, these circuits evolved into bugs with more than 1000 transistors on a chip. A proposed data system for Helios satellite will have approximately 130 bugs and a semiconductor count of more than 100,000, will weigh less than 1 N and use less than 1.2 W.
Totally depleted silicon diodes are discussed which are used as nuclear particle detectors in investigations of galactic and solar cosmic radiation and trapped radiation. A study of radiation and chemical effects on the diodes was conducted. Work on electron and proton irradiation of surface barrier detectors with thicknesses up to 1 mm was completed, and work on lithium-drifted silicon devices with thicknesses of several millimeters was begun.
Demonstration that meaningful galactic and solar cosmic radiation measurements can be carried out on deep space missions. The radioisotopic thermoelectric generators (RTGs) which must be used as a source of power and perhaps of heat are a problem, but with proper separation from the experiments, with orientation, and with some shielding the damage effects can be reduced to an acceptable level. The Pioneer spacecraft are crucial in that they are targeted at the heart of Jupiter's radiation belts, and should supply the details of those belts. The subsequent Grand Tour opportunities can be selected for those periods which result in larger distances of closest approach to Jupiter if necessary.
Solid state detector for electron spatial distribution measurements on OGO-F satellite, discussing design emphasizing reliability
Proton irradiation damage effects on current and noise in Si surface barrier transmission detectors for nuclear radiation
Solid state detector system for electron measurements on OGO-F
Low energy proton damage effects on silicon surface barrier transmission detectors to predict device lifetime in earth radiation belts conditions
Design criteria for solid state detectors for orbiting geophysical observatory onboard electron flux and spectra measurements
Galactic Jupiter Probes investigating Jupiter atmosphere and emissions and deep space cosmic radiation
Low energy proton damage effects on useful life of silicon surface barrier detectors operated in geomagnetically trapped radiation belts
Galactic space probe mission involving flight through asteroid belt and Jupiter flyby
Nuclear abundances of galactic and solar cosmic rays, discussing detector electronics system for measurement of particle energy spectrum