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in subjects: "Radiations 360605* -- Materials-- Radiation Effects"  
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Review of ultraviolet damage threshold measurements at Lawrence Livermore National Laboratory

Description: The results of damage threshold measurements made at LLNL using ultraviolet wavelength laser pulses are reviewed. Measurements were made with pulses from a krypton fluoride laser with wavelength of 248 nm and pulse duration of 20 ns and with Nd-glass laser pulses converted to the third harmonic wavelength of 355 nm with duration of 0.6 ns. Measurements are presented for transparent window materials, crystals and harmonic generation, single layer dielectric films of oxide and fluoride materials … more
Date: January 1, 1984
Creator: Lowdermilk, W.H. & Milam, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Facilities for studying radiation damage in nonmetals during irradiation

Description: Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses /sup 60/Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at co… more
Date: August 1, 1984
Creator: Levy, P.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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28-nm laser damage testing of LIF

Description: We have tested several samples of LIF, both single crystal and press forged, for damage resistance to 10-ns 248-nm pulses at 35 pps. The damage thresholds - the highest levels at which no damage could be produced - ranged from 4 to 6 J/cm/sup 2/ although some test sites survived irradiation at approx. 30 J/cm/sup 2/. We observed that bulk damage is the primary failure mechanism in single crystal and press forged samples and that both types exhibit the same resistance to laser damage.
Date: January 1, 1981
Creator: Foltyn, S. R. & Newman, B. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Predamage threshold electron emission from insulator and semiconductor surfaces

Description: Predamage electron emission shows a dependence on fluence, bandgap and wavelength consistent with multiphoton excitation across the bandgap and inconsistent with avalanche ionization and thermionic emission models. The electron emission scales with pulselength as 1/..sqrt..T. 6 references, 8 figures, 1 table.
Date: February 5, 1985
Creator: Siekhaus, W.J.; Kinney, J.H. & Milam, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Damage thresholds of thin film materials and high reflectors at 248 nm

Description: Twenty-ns, 248-nm KrF laser pulses were used to measure laser damage thresholds for halfwave-thick layers of 15 oxide and fluoride coating materials, and for high reflectance coatings made with 13 combinations of these materials. The damage thresholds of the reflectors and single-layer films were compared to measurements of several properties of the halfwave-thick films to determine whether measurements of these properties of single-layer films to determine whether measurements of these propert… more
Date: January 1, 1982
Creator: Rainer, F.; Lowdermilk, W.H.; Milam, D.; Carniglia, C.K.; Hart, T.T. & Lichtenstein, T.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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PINEX (Pinhold Neutron Experiment) fluor characteristics

Description: This report will describe recent experiments to characterize four fluors: BC-400, 408, 422, 430. Each fluor sample was 0.5 cm thick commensurate with our standard Electronic Pinhole Neutron Experiment (EL-PINEX) fluors. The important results are that the neutron-gamma sensitivity ratios did not change significantly, although the absolute gamma and neutron sensitivities decreased. 6 figs., 4 tabs.
Date: July 1, 1988
Creator: Koehler, H.; Kammeraad, J.; Davis, B. & Burns, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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New insights on the thermal decomposition of ammonium perchlorate from studies on very large single crystals. [Gamma rays]

Description: The large crystals were thermally decomposed at 227/sup 0/C, either without irradiation or after irradiation in water-cooled /sup 60/Co sources. The crystals were then examined with optical or scanning and transmission electron microscopes. Between 2 x 10/sup 4/ and 10/sup 6/R, the crystals are transparent but become translucent on heating. Higher doses result in opaqueness, pitting, and voids. Retentions of 70 to 96 percent are observed with large crystals. The decomposition is surface-related… more
Date: January 1, 1976
Creator: Herley, P. J. & Levy, P. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mechanical strength of low-temperature-irradiated polyimides: a five-to-tenfold improvement in dose resistance over epoxies

Description: Neutronics calculations by Engholm show that without additional shielding even the first fusion test reactors such as the Fusion Engineering Device will produce lifetime doses at magnet insulator locations that exceed the radiation tolerance of glass-fabric-filled (gff) epoxies now used. To explore the possible use of an alternative insulator, the mechanical strength of pure and recently available gff polyimides was studied as a function of gamma-ray irradiation at 4.9 K to 100 MGy (10/sup 10/ … more
Date: June 1, 1981
Creator: Coltman, R.R. Jr. & Klabunde, C.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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