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Basic radiation effects in electronics. Radiation effects in materials, electrical response in electronic components, and radiation effects units [Slides]
Basic questions for radiation effects in electronics are addressed.
Space electron radiation shielding bremsstrahlung and electron transmission
Space electron radiation shielding - electron and bremsstrahlung transmission and intensity measurements
Status of Galileo interim radiation electron model
Measurements of the high energy, omni-directional electron environment by the Galileo spacecraft Energetic Particle Detector (EDP) were used to develop a new model of Jupiter's trapped electron radiation in the jovian equatorial plane for the range 8 to 16 Jupiter radii.
Effects of electron radiation on unijunction transistors
Electron radiation effects on terminal characteristics of unijunction transistors
Effect of electron radiation on tv lens components
Electron radiation bombardment effect on optical properties of Nimbus satellite television camera lens
Electron radiation effects on the thermal expansion of graphite/resin composites
The effects of 1 MeV electron radiation on the thermal expansion characteristics of two graphite reinforced resin matrix composite systems were studied. Specimens of both graphite/epoxy (T300/5208) and graphite/polyimide (C6000/PMR15) were irradiated to a total dose of 6 x 10 to the 9th rads at two different rates. Dynamic mechanical analyses (DMA) were performed to study changes in resin chemistry. Thermal expansion results indicate that radiation did produce permanent residual strains of up to -70 x 10 to the -6th for the graphite/epoxy when exposed to temperatures up to +280 F. However, no permaanent changes in the coefficient of thermal expansion (CTE) were observed. No permanent residual strains or changes in the CTE attributable to radiation were observed for the graphite/polyimide specimens. DMA results indicate that electron radiation caused chemical changes in the epoxy matrix. These changes resulted in a lower glass transition temperature and broader 'rubbery region' which extended into the temperature range of the thermal expansion tests.
Electron radiation effects on silver-zinc cells
Electron radiation effects on cellophane separator in silver-zinc cells
Effect of electron radiation on silicon nitride insulated gate field effect transistors.
Electron radiation stability of silicon nitride insulated gate FET with passivation layers and heat treatment, noting contamination effects
Electron radiation damage effects in silicon surface-barrier detectors
Electron radiation bulk damage effects on Si surface barrier detectors, determining reverse leakage current density and alpha particle response changes
Investigation of electron-radiation-induced dielectric breakdowns in a typical capacitor meteoroid detector system
Electron radiation induced dielectric breakdowns in capacitor meteoroid detection system
Galileo measurements of the Jovian electron radiation environment
The Galileo spacecraft Energetic Particle Detector (EPD) has been used to map Jupiter's trapped electron radiation in the jovian equatorial plane for the range 8 to 16 Jupiter radii.
Influence of electron radiation and temperature on the cyclic, matrix dominated response of graphite-epoxy
The effects of electron radiation and elevated temperature on the matrix-dominated cyclic response of standard T300/934 and a chemically modified T300/934 graphite-epoxy are characterized. Both materials were subjected to 1.0 x 10 to the 10th rads of 1.0 MeV electron irradiation, under vacuum, to simulate 30 years in geosynchronous orbit. Cyclic tests were performed at room temperature and elevated temperature (121 C) on 4-ply unidirectional laminates to characterize the effects associated with irradiation and elevated temperature. Both materials exhibited energy dissipation in their response at elevated temperature. The irradiated modified material also exhibited energy dissipation at room temperature. The combination of elevated temperature and irradiation resulted in the most severe effects in the form of lower proportional limits, and greater energy dissipation. Dynamic-mechanical analysis demonstrated that the glass transition temperature, T(g), of the standard material was lowered 39 C by irradiation, wereas the T(g) of the modified material was lowered 28 C by irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated materials.
Proton Cancer Therapy Facilities in the U.S. - Status on Evaluation for Electronics Radiation Testing
This presentation is an overview of proton cancer therapy facilities in the U.S. Highlights include a status on evaluation for electronics radiation testing.
Effects of 22 MeV proton and 2.4 MeV electron radiation on boron and aluminum-doped silicon solar cells
Effects of 22 MeV proton and 2.4 MeV electron radiation on boron and aluminum doped silicon solar cells
Effects of cure temperature, electron radiation, and thermal cycling on P75/930 composites
Graphite/epoxy composites are candidates for future space structures due to high stiffness and dimensional stability requirements of these structures. Typical graphite/epoxy composites are brittle and have high residual stresses which often result in microcracking during the thermal cycling typical of the space environment. Composite materials used in geosynchronous orbit applications will also be exposed to high levels of radiation. The purpose of the present study was to determine the effects of cure temperature and radiation exposure on the shear strength and thermal cycling-induced microcrack density of a high modulus, 275 F cure epoxy, P75/930. The results from the P75/930 are compared to previously reported data on P75/934 and T300/934 where 934 is a standard 350 F cure epoxy. The results of this study reveal that P75/930 is significantly degraded by total doses of electron radiation greater than 10(exp 8) rads and by thermally cycling between -250 F and 150 F. The P75/930 did not have improved microcrack resistance over the P75/934, and the 930 resin system appears to be more sensitive to electron radiation-induced degradation than the 934 resin system.
Spectroscopic comparison of effects of electron radiation on mechanical properties of two polyimides
The differences in the radiation durabilities of two polyimide materials, Du Pont Kapton and General Electric Ultem, are compared. An explanation of the basic mechanisms which occur during exposure to electron radiation from analyses of infrared (IR) and electron paramagnetic resonance (EPR) spectroscopic data for each material is provided. The molecular model for Kapton was, in part, established from earlier modeling for Ultem (pp. 1293-1298 of IEEE Transactions on Nuclear Science, December 1984). Techniques for understanding the durability of one complex polymer based on the understanding of a different and equally complex polymer are demonstrated. The spectroscopic data showed that the primary radiation-generated change in the tensile properties of Ultem (a large reduction in tensile elongation) was due to crosslinking, which followed the capture by phenyl radicals of hydrogen atoms removed from gem-dimethyl groups. In contrast, the tensile properties of Kapton remained unchanged because radical-radical recombination, a self-mending process, took place.