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in subjects: "360605 -- Materials-- Radiation Effects"

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Edge-on ion irradiation of electron microscope specimens

A special technique is described for in situ transmission electron microscope (TEM) experiments involving simultaneous ion irradiation, in which the resultant phenomena are observed as in a cross-section TEM specimen. That is, instead of ion-irradiating the film or foil specimen normal to the major surfaces and observing in plan view (i.e., in the same direction), the specimen is irradiated edge-on (i.e., parallel to the major surfaces) and is observed normal to the depth direction with respect… more

Date: January 1, 1992

Creator: Otero, M. P. & Allen, C. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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DOE Task Force meeting on Electrical Breakdown of Insulating Ceramics in a High Radiation Field

This volume contains the abstracts and presentation material from the Research Assistance Task Force Meeting Electrical Breakdown of Insulating Ceramics in a High-Radiation Field.'' The meeting was jointly sponsored by the Office of Basic Energy Sciences and the Office of Fusion Energy of the US Department of Energy in Vail, Colorado, May 28--June 1, 1991. The 26 participants represented expertise in fusion, radiation damage, electrical breakdown, ceramics, and semiconductor and electronic stru… more

Date: August 1, 1991

Creator: Green, P.H. (comp.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Significance of radiation effects in solid radioactive waste

Proposed NRC criteria for disposal of high-level nuclear waste require development of waste packages to contain radionuclide for at least 1000 years, and design of repositories to prevent radionuclide release at an annual rate greater than 1 part in 100,000 of the total activity. The high-level wastes that are now temporarily stored as aqueous salts, sludges, and calcines must be converted to high-integrity solid forms that resist deterioration from radiation and other effects of long-term stor… more

Date: January 1, 1980

Creator: Permar, P H & McDonell, W R

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radiation damage studies related to nuclear waste forms

Much of the previously reported work on alpha radiation effects on crystalline phases of importance to nuclear waste forms has been derived from radiation effects studies of composite waste forms. In the present work, two single-phase crystalline materials, Gd/sub 2/Ti/sub 2/O/sub 7/ (pyrochlore) and CaZrTi/sub 2/O/sub 7/ (zirconolite), of relative importance to current waste forms were studied independently by doping with /sup 244/Cm at the 3 wt % level. Changes in the crystalline structure me… more

Date: December 1, 1981

Creator: Gray, W.J.; Wald, J.W. & Turcotte, R.P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A comparison of the neutron response of CR-39 made by different manufacturers

CR-39 was obtained from American Acrylics and Plastics, Inc. (A.A), N. E. Technology, Ltd. (N.E), and Tech/Ops Landauer, Inc. (LT). The dosemeters were exposed to radioisotopic neutron sources at SLAC, and moderated {sup 252}Cf at ORNL. The A.A. and N.E. dosemeters were electrochemically etched (pre-etch in 6.5 N KOH at 60{degrees}C for 1 hour and 45 minutes, a 5 hour etch at 3000 V and 60 Hz, a 23 minute blow-up step at 2 kHz and a post-etch for 15 minutes). Track densities were determined wit… more

Date: September 1, 1991

Creator: Ipe, N.E.; Liu, J.C. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Buddemeier, B.R. (Lawrence Livermore National Lab., CA (United States)); Miles, C.J. (Radiation Detection Co., Sunnyvale, CA (United States)) & Yoder, R.C. (Tech/OPS Landauer, Inc., Glenwood, IL (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Reaction of hydrogen and oxygen in the presence of concretes incorporating simulated radioactive waste

The radiolysis of contained water, with the potential of pressurization due to the accumulation of these radiolytically produced gases, has been identified as a major concern for radioactive wastes fixed in cementitious matrices. One estimate of the pressure build-up is that about 100 atmospheres pressure could accumulate in a standard canister containing alpha waste after 100,000 years. Since the radiolysis of concrete is dependent on the amount of unbound or free water present in the system, … more

Date: January 1, 1979

Creator: Katz, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Selected etching and annealing properties of Brazilian quartz crystals for solid state track recorder applications

The etching and annealing properties of Brazilian quartz crystals are under investigation to determine their suitability for use as solid state track recorders (SSTR) and damage monitors in nuclear reactor environments, where temperatures and neutron fluences are high. Observer objectivity in counting fission tracks has been established at the 1 to 2% level, and a method of standardizing chemical etching from one sample of quartz to another has been found. A method has also been found to make c… more

Date: January 1, 1981

Creator: Roberts, J.H.; Gold, R. & Ruddy, F.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effects of radiation damage to TMP (tetramethylpentane), TMS (tetramethylsilane) and liquid argon solutions

The effects of exposure of calorimeter liquids like tetramethylsilane (TMS), 2,2,4,4-tetramethylpentane (TMP) and liquid argon solutions to the large doses of ionizing radiation expected in the SCC environment is examined. Like other organic liquids TMS and TMP are decomposed by radiation to various products; thus, we must consider the effects these products may have on the calorimeter operation. Questions considered include how will radiation effect electron drift velocity and lifetime. Will g… more

Date: January 1, 1988

Creator: Holroyd, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Photogenerated carrier-induced reactions on uhv semiconductor surfaces

The objective for this experimental work was to examine the reaction mechanisms, half-collision dynamics, and other optically induced chemical effects, that are operable on a well characterized single-crystal semiconductor surface. Of particular interest were reactions induced by charge transfer from the semiconductor surface including hot carrier and thermalized carrier processes. The primary technique to measure the desorbed fragment translational energies was time-of-flight mass-spectroscopy… more

Date: May 28, 1992

Creator: Osgood, R.M. Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Assessment of grade H-451 graphite for replaceable fuel and reflector elements in HTGR

Experimental data for grade H-451 graphite are presented and assessed to support licensing of H-451 graphite for use as fuel element blocks in a high-temperature gas-cooled reactor (HTGR). Additional data from the literature on graphite grades similar to grade H-451 are presented to supplement the H-451 data. Evaluation programs at General Atomic Company (GA) covering characterization, irradiation, and oxidation studies, along with studies carried out in the Great Lakes Carbon Corporation H-451… more

Date: December 1, 1977

Creator: Engle, G. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Postirradiation examination and evaluation of Peach Bottom fuel test element FTE-6

Fuel test element FTE-6 was irradiated in the Peach Bottom high-temperature gas-cooled reactor (HTGR) for 645 equivalent full power days. Four fuel varieties, contained in H-327 graphite bodies, were tested. A primary result of this test has been to demonstrate acceptable performance even with calculated high stresses in the graphite bodies. Heterogeneous fuel loadings in the element caused local power peaking and azimuthal power variations, deforming the graphite fuel bodies and thereby causin… more

Date: September 1, 1977

Creator: Wallroth, C. F.; Holzgraf, J. F. & Jensen, D. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Properties of SYNROC-D nuclear waste form: a state-of-the-art reivew

SYNROC is a titanate-based ceramic waste form being developed to immobilize high-level nuclear reactor wastes. SYNROC-D is a unique variation of SYNROC designed to contain high-level defense wastes, particularly those in storage at the Savannah River Plant (SRP). In this report, we review results from physical property and performance tests on SYNROC-D containing simulated SRP wastes. These results provide a data base for comparing SYNROC-D with other defense waste forms. The test data are grou… more

Date: January 1, 1982

Creator: Campbell, J.; Hoenig, C.; Bazan, F.; Ryerson, F.; Guinan, M.; Van Konynenburg, R. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Radiation induced growth of micro crystallites

Generation of colloidal particles during the radiolysis of aqueous solutions was already observed in the early days of radiation chemistry. Systematic studies using radiation chemistry techniques as synthetic tools in the preparation of colloidal particles, primarily metallic particles, were begun approximately a decade ago in conjunction since they were found to catalyze multi-electron redox processes. A large number of metallic colloidal particles were then synthesized, including silver, gold… more

Date: January 1, 1991

Creator: Meisel, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Transient effects of ionizing radiation in Si, InGaAsP, GaAlSb, and Ge photodiodes

Certain military applications require the continuous operation of optoelectronic information transfer systems during exposure to ionizing radiation. In such an environment the optical detector can be the system element which limits data transmission. We report here the measured electrical and optical characteristics of an irradiation tolerant photodiode fabricated from a double heterojunction structure in the gallium aluminum antimonide (GaAlSb) ternary semiconductor system. A series of tests a… more

Date: January 1, 1980

Creator: Wiczer, J. J.; Barnes, C. E. & Dawson, L. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electron energy deposition in a multilayered carbon--uranium--carbon configuration and in semi-infinite uranium

Absolute measurements of electron energy deposition profiles are reported here for electrons incident on the multilayer configuration of carbon-uranium-carbon. These measurements were for normally incident source electrons at an energy of 1.0 MeV. To complement these measurements, electron energy deposition profiles were also obtained for electrons incident on semi-infinite uranium as a function of energy and angle of incidence. The results are compared with the predictions of a coupled electro… more

Date: October 1, 1977

Creator: Lockwood, G. J.; Miller, G. H. & Halbleib, J. A., Sr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Near-surface leaching studies of Pb-implanted Savannah River waste glass

The present experiments with Savannah River Plant simulated nuclear waste glass implanted with Pb ions, used Rutherford backscattering spectrometry and elastic recoil detection to follow in detail the changes in composition which occur in the near-surface region upon leaching in deionized water at 90/sup 0/C. Analyses of the leach solutions were made in an attempt to correlate the actual leach rates with the observed near-surface compositional changes. These experiments show that radiation dama… more

Date: January 1, 1982

Creator: Arnold, G. W.; Northrup, C. J. M. & Bibler, N. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Relative radiation sensitivity of insulators, stabilizers, and superconductors

The objective of this work was to compare the radiation sensitivity of the various parts of superconducting magnet systems. Using the radiation spectra calculated by Engholm for the Engineering Test Facility (ETF) toroidal field magnet inboard leg and available data on radiation effects, commonly used magnet components were ranked in order of radiation sensitivity. It was found that epoxy-based insulators and copper and aluminum stabilizers were the most sensitive parts of the magnets, more sen… more

Date: January 15, 1982

Creator: Van Konynenburg, R.A. & Guinan, M.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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TNF (trinitro-9-fluorenone)-doped mylar: A rad-hard film dielectric developed for pulse-discharge capacitors

Development of rad-hard (radiation tolerant) film dielectric suitable for discharge capacitor application has recently been completed. This dielectric is made by doping polyethylene terephthalate film (Mylar C)* with the material, 2,4,7,-trinitro-9-fluorenone (TNF) which acts as an electron acceptor to photoconduction electrons in the film. It has been shown that neither the presence of TNF in the film, nor the process which places the TNF in the film, has any adverse effects on the electrical … more

Date: January 1, 1991

Creator: Bischoff, G.C. (General Electric Co., Largo, FL (USA). Neutron Devices Dept.) & Edwards, L.R. (Sandia National Labs., Albuquerque, NM (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Use of run statistics to validate tensile tests

In tensile testing of irradiated graphites, it is difficult to assure alignment of sample and train for tensile measurements. By recording location of fractures, run (sequential) statistics can readily detect lack of randomness. The technique is based on partitioning binomial distributions.

Date: January 1, 1981

Creator: Eatherly, W.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Review of radiation effects in solid-nuclear-waste forms

Radiation effects on the stability of high-level nuclear waste (HLW) forms are an important consideration in the development of technology to immobilize high-level radioactive waste because such effects may significantly affect the containment of the radioactive waste. Since the required containment times are long (10/sup 3/ to 10/sup 6/ years), an understanding of the long-term cumulative effects of radiation damage on the waste forms is essential. Radiation damage of nuclear waste forms can r… more

Date: September 1, 1981

Creator: Weber, W.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Recent developments in electron degradation theory: selected topics

The electron degradation spectrum, essentially an energy distribution function of an irradiated system, provides a general basis for determining, not only the fate of the incident (or internally produced) radiation, but also for determining the initial or primary yields of the various excited states of the medium. The degradation spectrum thus describes the initial response of the medium to the radiation. This review-type paper focuses on results obtained in calculations for molecular hydrogen … more

Date: January 1, 1979

Creator: Douthat, Daryl A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Strength of irradiated graphite: a review

Experimental data on the mechanical strength of nuclear graphite subjected to fast neutron irradiation are reviewed. At fluences below the turnaround point, the mean tensile, flexural, or compressive strength, S, increases over the unirradiated value, S/sub 0/, in a manner related to the irradiation-induced change in Young's modulus, E: S/S/sub 0/ = (E/E/sub 0/)/sup K/. The exponent, k, takes a value between 0.5 and 1, depending on the graphite grade, the irradiation temperature, and the method… more

Date: July 1979

Creator: Price, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radiation-induced sodium-metal-colloid formation in natural rock salt from different geological localities

Radiation damage has been studied in natural rock salt from various localities, including potential repository sites. In the 100 to 300 C range the damage consists of point defects, primarily F-centers, and colloidal metal sodium particles. With increasing dose the F-centers grow to a saturation level, reached at 10/sup 7/ to 10/sup 8/ rad, that decreases with increasing temperature to a negligible level at 300 C. Colloid concentration vs. irradiation-time curves follow nucleation and growth cu… more

Date: January 1, 1981

Creator: Loman, J. M.; Levy, P. W. & Swyler, K. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Database of average-power damage thresholds at 1064 nm

We have completed a database of average-power, laser-induced, damage thresholds at 1064 nm on a variety of materials. Measurements were made with a newly constructed laser to provide design input for moderate and high average-power laser projects. The measurements were conducted with 16-ns pulses at pulse-repetition frequencies ranging from 6 to 120 Hz. Samples were typically irradiated for time ranging from a fraction of a second up to 5 minutes (36,000 shots). We tested seven categories of sa… more

Date: December 14, 1987

Creator: Rainer, F.; Hildum, E.A. & Milam, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department