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Calibrations of a tritium extraction facility

Description: A tritium extraction facility has been built for the purpose of measuring the absolute tritium concentration in neutron-irradiated lithium metal samples. Two independent calibration procedures have been used to determine what fraction, if any, of tritium is lost during the extraction process. The first procedure compares independently measured /sup 4/He and /sup 3/H concentrations from the /sup 6/Li(n,..cap alpha..)T reaction. The second procedure compared measured /sup 6/Li(n,..cap alpha..)T//sup 197/Au (n,..gamma..)/sup 198/Au thermal neutron reaction rate ratios with those obtained from Monte Carlo calculations using well-known cross sections. Both calibration methods show that within experimental errors (approx. 1.5%) no tritium is lost during the extraction process.
Date: January 1, 1983
Creator: Bretscher, M.M.; Oliver, B.M. & Farrar, H. IV
Partner: UNT Libraries Government Documents Department

Effect of interacting particles on primordial nucleosynthesis

Description: We modify the standard model for big-bang nucleosynthesis to allow for the presence of a generic particle species, i.e., one which maintains good thermal contact with either the photons or the light neutrino species throughout the epoch of primordial nucleosynthesis. The production of D, /sup 3/He, /sup 4/He, and /sup 7/Li is calculated as a function of the mass, degrees of freedom, and spin statistics of the generic particle. We show that in general, the effect of an additional generic species cannot simply be parameterized as the equivalent number of additional light neutrino species. The presence of generic particles also affects the predicted value for the neutrino-to-photon temperature ratio.
Date: May 1, 1986
Creator: Kolb, E.W.; Turner, M.S. & Walker, T.P.
Partner: UNT Libraries Government Documents Department

Calculated thickness of tungsten alloy required for specified attenuation of gamma radiation from sup 137 CS

Description: The traditional method of evaluating and calibrating health physics instruments is to use a calibrator that consists of a single high-activity gamma radiation source with different attenuators to select the radiation level desired for tesing. To have accurate radiation intensities inside the calibrator cavity, the attenuators must be designed from precise absorption calculations. This paper reports calculations made to determine the thickness of tungsten alloy metal required for specific attenuation. These calculations include the buildup contribution by secondary scattering radiation, and they are compared to values calculated with the buildup factor omitted. 3 refs., 2 figs., 3 tabs.
Date: January 1, 1991
Creator: Chiles, M.M.; Allin, G.W. & Pace, J.V. III.
Partner: UNT Libraries Government Documents Department

Capsule calorimeter development report

Description: A capsule calorimeter has been designed, fabricated, and tested that is capable of measuring the rate of thermal energy generation of a capsule source with an accuracy of plus or minus five percent over a range of 300 watts to 1,000 watts of power. Three operating modes were investigated. The rate of temperature rise mode of operation was found to be the superior operating mode based on accuracy, time cycle, and simplicity of operation. This mode of operation is recommended for use in the encapsulation plant for performing calorimetric determinations on the strontium and cesium capsules that will be produced in the plant. The heat generation data collected by calorimetry will be used for isotopic assay of the capsule sources. The capsule calorimeter is specifically designed for installation into a remotely operated hot cell.
Date: October 2, 1972
Creator: Hall, J.C.
Partner: UNT Libraries Government Documents Department

An assessment of the base blanket for ITER

Description: Ideally, the ITER base blanket would provide the necessary tritium for the reactor to be self-sufficient during operation, while having minimal impact on the overall reactor cost, reliability and safety. A solid breeder blanket has been developed in CDA phase in an attempt to achieve such objectives. The reference solid breeder base blanket configurations at the end of the CDA phase has many attractive features such as a tritium breeding ratio (TBR) of 0.8--0.9 and a reasonably low tritium inventory. However, some concerns regarding the risk, cost and benefit of the base blanket have been raised. These include uncertainties associated with the solid breeder thermal control and the potentially high cost of the amount of Be used to achieve high TBR and to provide the necessary thermal barrier between the high temperature solid breeder and low temperature coolant. This work addresses these concerns. The basis for the selection of a breeding blanket is first discussed in light of the incremental risk, cost and benefits relative to a non-breeding blanket. Key issues associated with the CDA breeding blanket configurations are then analyzed. Finally, alternative schemes that could enhance the attractiveness and flexibility of a breeding blanket are explored.
Date: January 1, 1991
Creator: Raffray, A.R.; Abdou, M.A. & Ying, A.
Partner: UNT Libraries Government Documents Department

Measurement of the energy dependent beta asymmetry in the decay of /sup 8/Li

Description: Progress is reported on a new measurement of the beta decay asymmetry in /sup 8/Li. Polarized /sup 8/Li is produced via the reaction /sup 7/Li(d,p)/sup 8/Li using vector polarized deuterons from a crossed beam polarized source. Plastic scintillation electron counters are used to measure asymmetry, tensor polarization correlation and to monitor beam current. Results are graphed and systematic error sources are discussed. 4 refs. (LEW)
Date: January 1, 1985
Creator: Bigelow, R.A.; Quin, P.A.; Freedman, S.J. & Napolitano, J.
Partner: UNT Libraries Government Documents Department

Alpha particle diagnostic beam line system to generate an intense Li/sup 0/ beam with an ORNL SITEX source

Description: The Oak Ridge National Laboratory (ORNL) SITEX (Surface Ionization with Transverse Extraction) negative ion source utilizes a 100-V/20-A reflex arc discharge in a 1300-gauss magnetic field to generate Cs+ ions and H+ or D+ ions, depending on the beam required. A shaped molybdenum plate is placed directly behind the arc column. Cesium coverage on this plate is used to minimize the surface work function, which requires two-thirds of a monolayer coverage. Cesium coverage ia adjusted both by cesium flow control into the arc discharge chamber and by temperature control of the converter using gaseous-helium cooling channels in the converter plate. Normal converter operational temperatures are 300/sup 0/ to 500/sup 0/C H/sup -//D/sup -/ beams are generated at the biased converter surface (-150 V with respect to the anode) by Cs/sup +/ sputtering of absorbed hydrogen or deuterium and by the reflection-conversion mechanism of H/sup +//D/sup +/ ions which strike the converter surface at 150 eV. The negative ions are accelerated through the 150-V plasma sheath at the converter surface and are focused by the converter geometry and magnetic field so as to pass through the exit aperture with minimum angular divergence. The ion optics of the SITEX accelerator has been calculated using the ORNL 3-D optics code and results in a divergence perpendicular to the slot of theta/sub perpendicular rms/ = 0.35/sup 0/ and parallel to the slot of theta/sub parallel rms/ = 0.18/sup 0/. This beam divergence should be adequate for injection into a radio frequency quadrupole (RFQ) for further acceleration.
Date: January 1, 1985
Creator: Dagenhart, W.K.; Stirling, W.L.; Tsai, C.C. & Whealton, J.H.
Partner: UNT Libraries Government Documents Department

Cesium diffusion in graphite

Description: Experiments on diffusion of /sup 137/Cs in five types of graphite were performed. The document provides a completion of the report that was started and includes a presentation of all of the diffusion data, previously unpublished. Except for data on mass transfer of /sup 137/Cs in the Hawker-Siddeley graphite, analyses of experimental results were initiated but not completed. The mass transfer process of cesium in HS-1-1 graphite at 600 to 1000/sup 0/C in a helium atmosphere is essentially pure diffusion wherein values of (E/epsilon) and ..delta..E of the equation D/epsilon = (D/epsilon)/sub 0/ exp (-..delta..E/RT) are about 4 x 10/sup -2/ cm/sup 2//s and 30 kcal/mole, respectively.
Date: May 1, 1980
Creator: Evans, R.B. III; Davis, W. Jr. & Sutton, A.L. Jr.
Partner: UNT Libraries Government Documents Department

Cesium-137 source material for an irradiator

Description: The feasibility of using /sup 137/Cs for the gamma source in sludge irradiators is discussed. It was concluded that /sup 137/Cs, because of its availability in large quantities as a by-product of fission in nuclear reactors, is an excellent candidate source for use in sewage sludge irradiators. The capsules used to store /sup 137/CsCl in the Waste Encapsulation and Storage Facility embody the technology gained by extensive development and experience during the past 25 years. The WESF capsule provides a rugged, well-proved containment of /sup 137/CsCl that has been shown to be resistant to a series of unusual stresses.
Date: January 1, 1980
Creator: Lamb, E.
Partner: UNT Libraries Government Documents Department

Gamma-ray spectral calculations for uranium borehole logging

Description: Gamma-ray transport calculations were performed to determine the energy distribution of gamma rays inside a borehole introduced into an infinite medium. The gamma rays from the naturally occurring radioactive isotopes of potassium, thorium, and uranium were uniformly distributed in a sandstone formation (having a porosity of 0.30 and a saturation of 1.0) surrounding the borehole. A sonde was placed coaxially inside the borehole. Parametric studies were done to determine how the borehole radius, borehole fluid, and borehole casing influence the gamma-ray flux inside the sonde.
Date: June 1, 1980
Creator: Close, D.A.; Evans, M.L. & Jain, M.
Partner: UNT Libraries Government Documents Department

Mass-reduced quantum numbers: application to the isotopic lithium hydrides (X/sup 1/B/sup +/)

Description: The massed-reduced quantum number (MRQN) method of combining isotopic data is applied to the lithium hydride X/sup 1/..sigma../sup +/ ground state. The ..delta..G(eta) = ..mu../sup /sup 1///sub 2// ..delta..G(v), B(eta) = ..mu..B(v) and D(eta) = ..mu../sup 2/D(v) isotopically-combined functions are obtained. An isotopically-combined Rydberg-Klein Rees (ICRKR) potential is constructed using the G(eta) and B(eta) functions. Evidence for breakdown of the Born-Oppenheimer approximation is presented and examined. The Dunham, Simons-Parr-Finlan, and Thakkar methods of potential expansion are also applied to lithium hydride and compared to the RKR Potential.
Date: January 1, 1977
Creator: Li, K.C. & Stwalley, W.C.
Partner: UNT Libraries Government Documents Department

Radiative lifetimes for vibrational levels of the B /sup 1/PI state of /sup 7/LiH. [Probabilities, bound-free probability]

Description: Newly calculated radiative transition probabilities for the B /sup 1/PI ..-->.. X /sup 1/..sigma../sup +/ and A /sup 1/..sigma../sup +/ emission bands of /sup 7/LiH are used to calculate the radiative lifetime of the various vibrational levels (0 less than or equal to v' less than or equal to 2) of B /sup 1/PI LiH. An estimate of the B ..-->.. X bound-free emission probability is also included, although the lifetimes are dominated by the B ..-->.. X bound-bound emission. The calculated radiative lifetimes increase rapidly with v' from 11.3 nsec at v' = 0 to 17.0 nsec at v' = 1 and then 24.0 nsec at v' = 2.
Date: January 1, 1978
Creator: Zemke, W.T. & Stwalley, W.C.
Partner: UNT Libraries Government Documents Department

Radiative and nonradiative lifetimes for vibrational levels of the A /sup 1/. sigma. /sup +/ state of /sup 7/LiH. [Transition probabilities]

Description: Newly calculated radiative transition probabilities for the A /sup 1/..sigma../sup +/ ..-->.. X /sup 1/..sigma../sup +/ (v' -v'') emission bands of /sup 7/LiH re used to calculate the radiative lifetime of the various vibrational levels (0 < or = v' < or = 26) of A /sup 1/..sigma../sup +/ LiH. For higher levels, an estimate of the bound-to-free emission probability is also needed and included. For the highest two levels, A /sup 1/..sigma../sup +/ ..-->.. B /sup 1/PI emission is possible and has been included, but makes a negligible contribution to the radiative lifetime. The calculated radiative lifetimes increase with v' from 28.9 nsec at v' = 0 to 36.1 nsec at v' = 16 and then decrease to 27.1 nsec at v' = 26. They are found to be in good agreement with measured total lifetimes, implying the nonradiative (predissociative) lifetime for the measured levels is approximately > 10/sup -7/ seconds, in accord with simple theoretical expectations.
Date: January 1, 1977
Creator: Zemke, W.T.; Crooks, J.B. & Stwalley, W.C.
Partner: UNT Libraries Government Documents Department

Radiative transition probabilities for the A /sup 1/. sigma. --X /sup 1/. sigma. /sup +/ bands of /sup 7/LiH. [Tables]

Description: The recently reported (J. Chem. Phys. 66, 5412 (1977)) hybrid potential curves for the X /sup 1/..sigma../sup +/ and A /sup 1/..sigma../sup +/ states of LiH are combined with the ab initio transition moments of Docken and Hinze (J. Chem. Phys. 57, 4936 (1972)) to calculate radiative transition probabilities between all upper (v' < or = 26) and all lower (v'' < or = 23) vibrational levels of /sup 7/LiH. By far the strongest single band found is the 23 to 26 band between the highest ''long-range'' levels in each potential. A comparison with experimental intensity observations is made; it appears that the experiments are globally in accord with calculations, but with some detailed differneces discussed herein.
Date: January 1, 1977
Creator: Zemke, W.T. & Stwalley, W.C.
Partner: UNT Libraries Government Documents Department

Applications of high resolution NMR to geochemistry: crystalline, glass, and molten silicates

Description: The nuclear spin interactions and the associated quantum mechanical dynamics which are present in solid state NMR are introduced. A brief overview of aluminosilicate structure is presented and crystalline structure is then reviewed, with emphasis on the contributions made by /sup 29/Si NMR spectroscopy. The local structure of glass aluminosilicates as observed by NMR, is presented with analysis of the information content of /sup 29/Si spectra. A high-temperature (to 1300/sup 0/C) NMR spectroscopic investigation of the local environment and dynamics of molecular motion in molten aluminosilicates is described. A comparison is made of silicate liquid, glass, and crystalline local structure. The atomic and molecular motions present in a melt are investigated through relaxation time (T/sub 1/ and T/sub 2/) measurements as a function of composition and temperature for /sup 23/Na and /sup 29/Si.
Date: November 1, 1985
Creator: Schneider, E.
Partner: UNT Libraries Government Documents Department

Engineering problems of the fusion breeder

Description: A study of fission suppressed blankets for the tandem mirror not only showed such blankets to be feasible but also to be safer than fissioning blankets. Such hybrids could produce enough fissile material to support up to 17 light water reactors of the same nuclear power rating. Beryllium was compared to /sup 7/Li for neutron multiplication; both were considered feasible but the blanket with Li produced 20% less fissile fuel per unit of nuclear power in the reactor. The beryllium resource, while possibly being too small for extensive pure fusion application, would be adequate (with carefully planned industrial expansion) for the hybrid because of the large support ratio, and hence few hybrids required. Radiation damage and coatings for beryllium remain issues to be resolved by further study and experimentation. Molten salt reprocessing was compared to aqueous solution reprocessing (thorex). The molten salt reprocessing cost is $3.4/g fissile, whereas aqueous reprocessing cost $24 or $43/g for the thorium metal or oxide fuel form.
Date: October 22, 1981
Creator: Moir, R.W.; Lee, J.D. & Barr, W.L.
Partner: UNT Libraries Government Documents Department

Projection of needs for gamma radiation sources and other radioisotopes and assessment of alternatives for providing radiation sources

Description: Pacific Northwest Laboratory reviewed the projected uses and demands for a variety of nuclear byproducts. Because the major large-scale near-term demand is for gamma irradiation sources, this report concentrates on the needs for gamma sources and evaluates the options for providing the needed material. Projections of possible growth in the irradiation treatment industry indicate that there will be a need for 180 to 320 MCi of /sup 60/Co (including /sup 137/Cs equivalent) in service in the year 2000. The largest current and projected use of gamma irradiation is for the sterilization of medical devices and disposable medical supplies. Currently, 40% of US disposable medical products are treated by irradiation, and within 10 years it is expected that 90% will be treated in this manner. Irradiation treatment of food for destruction of pathogens or parasites, disinfestation, or extension of allowable storage periods is estimated to require an active inventory of 75 MCi of /sup 60/Co-equivalent gamma source in about a decade. 90 refs., 7 figs., 25 tabs.
Date: June 1, 1989
Creator: Ross, W.A.; Jensen, G.A.; Clark, L.L.; Eakin, D.E.; Jarrett, J.H.; Katayama, Y.B. et al.
Partner: UNT Libraries Government Documents Department

Source efficiency calculations for /sup 137/Cs irradiators

Description: The efficiency of radiation sources used for radiation treatment is important in the overall economics of irradiators. The report examines design optimization for a /sup 137/Cs radiation source. The initial source design used is currently being fabricated at the Waste Encapsulation and Storage Facility (WESF). Although the current source was intended for long term storage and isolation of the cesium, it has potential for use as an irradiator. Modifications to the source which were examined include: optimum cylinder dia is 1 in.; optimum stainless steel wall thickness is about 0.1 in., thicker walls will reduce source efficiency, while thinner walls increase the likelihood of wall failure; and a cesium-titanate ceramic combines the advantages of good source efficiency with low solubility and low leachability. The cost to modify the present WESF facility does not appear to justify these design changes. However, new facilities could incorporate this design to obtain optimum source efficiency.
Date: September 1, 1977
Creator: Libby, R.A.
Partner: UNT Libraries Government Documents Department

Characterization of heat treatment induced changes in Li--Na beta-alumina single crystals

Description: Single crystals of lithium--sodium beta alumina with 40 to 95% substitution of Li/sup +/ for Na/sup +/ were annealed in air and in vacuum at temperatures up to 1000/sup 0/C. The specimens were examined before and after each heat treatment by pulsed NMR, Raman scattering, infrared absorption, and x-ray diffraction. After annealing at 600/sup 0/C or above, the two original Raman bands due to /sup 7/Li/sup +/ vibrations merged into a single peak accompanied by a narrowing of spinel block phonon bands. The 1000/sup 0/C annealing introduced a broad /sup 7/Li NMR response and substantially reduced narrow line /sup 7/Li intensity. X-ray difffraction patterns showed that a second phase grows epitaxially with the beta-alumina structure as a result of high temperature heat treatment. The present results suggest that the thermal induced changes observed are due to diffusion of lithium out of the conducting plane and into the spinel-block.
Date: January 1, 1979
Creator: Dubin, R.R.; Kasper, J.S.; Bates, J.B. & Kaneda, T.
Partner: UNT Libraries Government Documents Department

Summary of potassium/argon dating, 1981. Topical report

Description: The analytical results for the last fiscal year effort in potassium/argon dating in support of US Department of Energy programs are summarized. Nearly 100 new dates have been generated. Recalibration of the argon extraction tables resulted in refinement of values for tracer ratios and depletion constants for our two extraction lines. Tracer ratios are ({sup 36}Ar/{sup 38}Ar){sub T} = 0.0308 and 0.0000449; ({sup 40}Ar/{sup 38}Ar){sub T} = 0.0501 and 0.0014 for extraction tables 1 and 2, respectively. Tracer depletion constants are -0.0002250 and -0.0005501 for tables 1 and 2, respectively. Initial values for the argon tracer pipettes are 3.2522 x 10{sup -11} moles and 3.9329 x 10{sup -11} moles for tables 1 and 2, respectively.
Date: September 1, 1981
Creator: Evans, S.H. Jr. & Brown, F.H.
Partner: UNT Libraries Government Documents Department

Major compound-dependent variations of sup 10 B(n. alpha. ) sup 7 Li RBE for the 9L RAT gliosarcoma in vitro and in vivo

Description: Relative biological effectiveness (RBE) values for the high linear-energy-transfer (LET) radiations produced during born neutron capture therapy (BNCT) were determined using the 9L rat gliosarcorna both in vitro and as an intracerebral tumor. In the absence of {sup 10}B, the combined effect of the recoiling protons from the {sup 14}N(n,p){sup 14}C and the {sup 1}H(n,n{prime})p reactions, compared to an iso-effect endpoint produced by 250 kVp x-rays, yielded RBEs for these high-LET protons of 4.4 in vitro and 3.8 in an in vivo/in vitro assay. RBEs for the {sup 10}B(n,{alpha}){sup 7}Li reaction were calculated from cell survival data following reactor irradiation in the presence or in the absence of the either of the amino acid, p-boronophenylalanine (BPA) or the sulfhydryl dodecaborane dimer (BSSB). With BPA, RBE values ranged from 3.5 to 11.4, while under the same set of conditions with BSSB, RBE values ranged from 1.1 to 4.3. In vitro, higher RBEs for the {sup 10}B(n,{alpha}){sup 7}Li reaction using BPA than with BSSB suggest a difference in distribution of {sup 10}B relative to the nucleus.
Date: January 1, 1991
Creator: Coderre, J.A.; Makar, M.S.; Micca, P.L.; Nawrocky, M.M.; Joel, D.D. & Slatkin, D.N.
Partner: UNT Libraries Government Documents Department

A fragment separator at LBL for beta-NMR experiment

Description: The Beam 44 fragment separator was built at the Bevalac of LBL for NMR studies of beta emitting nuclei. {sup 37}K, {sup 39}Ca, and {sup 43}Ti fragments originating from {sup 40}Ca and {sup 46}Ti primary beams were separated by the separator for NMR studies on these nuclei. Nuclear spin polarization was created in {sup 39}Ca and {sup 43}Ti using the tilted foil technique (TFT), and the magnetic moment of {sup 43}Ti was deduced. Fragment polarization was measured for {sup 37}K and {sup 39}Ca emitted to finite deflection angles. The Beam 44 fragment separator in combination with a proper polarization technique, such as TFT or fragment polarization, has been very effective for such NMR studies.
Date: March 1, 1992
Creator: Matsuta, K.; Ozawa, A.; Nojiri, Y.; Minamisono, T.; Fukuda, M.; Kitagawa, A. et al.
Partner: UNT Libraries Government Documents Department

Nondestructive assay technology for uranium resource evaluation. Infinite medium calculations. Final report

Description: A discrete ordinates transport code has been used to transport gamma rays from the decay of the naturally occurring radioactive isotopes of potassium, uranium, and thorium through an infinite homogeneous medium. Parametric studies varying the medium formation (i.e., shale and sandstone), porosity, and saturation were made to determine their effects on the calculated gamma-ray spectra. In addition, the effect on the gamma-ray spectra of trace quantities of heavy elements was studied by varying the uranium concentration in the formation from 0 to 6% by weight.
Date: March 1, 1979
Creator: Jain, M.; Evans, M.L. & Close, D.A.
Partner: UNT Libraries Government Documents Department