Several proteins involved in the response to DNA doublestrand breaks (DSB) f orm microscopically visible nuclear domains, orfoci, after exposure to ionizing radiation. Radiation-induced foci (RIF)are believed to be located where DNA damage occurs. To test thisassumption, we analyzed the spatial distribution of 53BP1, phosphorylatedATM, and gammaH2AX RIF in cells irradiated with high linear energytransfer (LET) radiation and low LET. Since energy is randomly depositedalong high-LET particle paths, RIF along these paths should also berandomly distributed. The probability to induce DSB can be derived fromDNA fragment data measured experimentally by pulsed-field gelelectrophoresis. We used this probability in Monte Carlo simulations topredict DSB locations in synthetic nuclei geometrically described by acomplete set of human chromosomes, taking into account microscope opticsfrom real experiments. As expected, simulations produced DNA-weightedrandom (Poisson) distributions. In contrast, the distributions of RIFobtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) werenon-random. This deviation from the expected DNA-weighted random patterncan be further characterized by "relative DNA image measurements." Thisnovel imaging approach shows that RIF were located preferentially at theinterface between high and low DNA density regions, and were morefrequent than predicted in regions with lower DNA density. The samepreferential nuclear location was also measured …

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Two Si-based spintronic materials, a Mn-Si digital ferromagnetic heterostructure ({delta}-layer of Mn doped in Si) with defects and dilutely doped Mn{sub x}Si{sub 1-x} alloy are investigated using a density-functional based approach. We model the heterostructure and alloy with a supercell of 64 atoms and examine several configurations of the Mn atoms. We find that 25% substitutional defects without vacancies in the {delta} layer diminishes half metallicity of the DFH substantially. For the alloy, the magnetic moment M ranges from 1.0-9.0 {mu}{sub B}/unit-cell depending on impurity configuration and concentration. Mn impurities introduce a narrow band of localized states near E{sub F}. These alloys are not half metals though their moments are integer. We explain the substantially different magnetic moments.

The relative stopping powers for 300 Mev protons of H, Li, Be, C, Al, Fe, Cu, Ag, Sn, W, Pb, and U have been measured. The results are shown in Table I. The energy spent per ion-pair production in the gases H{sub 2}, He, N{sub 2}, O{sub 2}, and A at 340 Mev proton energy has also been measured. The results are shown in Table II.

The Performance Demonstration Program (PDP) for Nondestructive Assay (NDA) is a test program designed to yield data on measurement system capability to characterize drummed transuranic (TRU) waste generated throughout the Department of Energy (DOE) complex. The tests are conducted periodically and provide a mechanism for the independent and objective assessment of NDA system performance and capability relative to the radiological characterization objectives and criteria of the Office of Characterization and Transportation (OCT). The primary documents requiring an NDA PDP are the Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC), which requires annual characterization facility participation in the PDP, and the Quality Assurance Program Document (QAPD). This NDA PDP implements the general requirements of the QAPD and applicable requirements of the WAC. Measurement facilities must demonstrate acceptable radiological characterization performance through measurement of test samples comprised of pre-specified PDP matrix drum/radioactive source configurations. Measurement facilities are required to analyze the NDA PDP drum samples using the same procedures approved and implemented for routine operational waste characterization activities. The test samples provide an independent means to assess NDA measurement system performance and compliance per criteria delineated in the NDA PDP Plan. General inter-comparison of NDA measurement system performance among DOE …

The commonly used current-voltage characteristics are foundinadequate for describing the pulsed nature of the high power impulsemagnetron sputtering (HIPIMS) discharge, rather, the description needs tobe expanded to current-voltage-time characteristics for each initial gaspressure. Using different target materials (Cu, Ti, Nb, C, W, Al, Cr) anda pulsed constant-voltage supply it is shown that the HIPIMS dischargestypically exhibit an initial pressure dependent current peak followed bya second phase that is power and material dependent. This suggests thatthe initial phase of a HIPIMS discharge pulse is dominated by gas ionswhereas the later phase has a strong contribution from self-sputtering.For some materials the discharge switches into a mode of sustainedself-sputtering. The very large differences between materials cannot beascribed to the different sputter yields but they indicate thatgeneration and trapping ofsecondary electrons plays a major role forcurrent-voltage-time characteristics. In particular, it is argued thatthe sustained self-sputtering phase is associated with thegeneration ofmultiply charged ions because only they can cause potential emission ofsecondary electrons whereas the yield caused by singly charged metal ionsis negligibly small.

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For heavy ion inertial fusion application, a combination of a laser ion source and direct plasma injection scheme into an RFQ is proposed. The combination might provide more than 100 mA of singly charged heavy ion beam from a single laser shot. A planned feasibility test with moderate current is also discussed.

Work on this project is focused on developing design and licensing information for the model facility. Final deliverables were prepared this period to submit to DOE for the licensing and high-density rack sub-tasks. DOE revised and reduced the scope of the 1981 AFR contract in June of 1981. Work is progressing satisfactorily to close out the remaining tasks under the revised scope by September 30, 1981.

Nuclear stopping and energy deposition into the central rapidity region of ultrarelativistic heavy-ion collisions are studied through the application of a model incorporating hydrodynamic baryon flow coupled to a self-consistent field calculated in the flux tube model. Ultrarelativistic heavy ion collisions are modeled in which the nuclei have passed through each other and as a result are charged and heated.

A yin-yang pair of liquid-helium (LHe) cooled, superconducting magnets were tested last year at the Lawrence Livermore National Laboratory (LLNL) as part of a series of tests with the Mirror Fusion Test Facility (MFTF). These tests were performed to determine the success of engineering design used in major systems of the MFTF and to provide a technical base for rescoping from a single-mirror facility to the large tandem-mirror configuration (MFTF-B) now under construction. The magnets were cooled, operated at their design current and magnetic field, and warmed to atmospheric temperature. In this report, we describe their thermal behavior during these tests.

ATA is a pulsed, 50 ns 10 KA, 50 MeV linear induction electron accelerator at LLNL. The ETA could be used as an injector for ATA. However the possibility of building a new injector gun for ATA, raised the question as to what changes from the ETA gun in electrode dimensions or potentials, if any, should be considered. In this report the EBQ code results for the four electrode configurations are reviewed and an attempt is made to determine the geometrical scaling laws appropriate to these ETA type gun geometries. Comparison of these scaling laws will be made to ETA operation. The characteristic operating curves for these geometries will also be presented and the effect of washer position determined. It will be shown that emittance growth will impose a limitation on beam current for a given anode potential before the virtual cathode limit is reached.

Seismic monitoring of the northern section of the Imperial Valley region in Southern California has been underway since 1973, in order to study in detail the relationship between geothermal areas and earthquakes. A description of the 22-station network and a list of preliminary data on earthquakes recorded by the network from January 1977 through March 1977 are presented.

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This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted during the first quarter of 1992. It includes the analytical data, field data, data review, quality control, and other documentation for this program; provides a record of the program's activities; and serves as an official document of the analytical results.

Work on this project is focused on demonstrating disassembly and encapsulation of nuclear fuels as a means to increase spent fuel storage. The effort commenced on April 17, 1980, and is progressing satisfactorily. The Equipment/Procedure Preparation sub-task is essentially complete. The Equipment Demonstration sub-task and the Process Assessment Studies sub-task continue. The equipment design effort associated with the first sub-task, the component testing and checking associated with the second sub-task, and the technical studies and investigations associated with the latter sub-task continue to verify the feasibility of this concept to enhance the use of fuel storage resources.

In order to evaluate entry into the atmosphere of an oblate (equatorial bulge) earth a standard atmosphere was used in conjunction with the standard rotating oblate spheroid. The density variation encountered in any one polar orbit around the earth will vary by about a factor of ten, due to oblateness. Therefore, the important effects on the re-entry trajectory are atmospheric density and oblateness of the earth. The SNAP configuration burn up characteristics will differ considerably between the steep (6/sup 0/) entry of the NASA Scout test and the orbital decay trajectory. However, the test can verify heat transfer rates on the actual configuration, and by proper calculation of material response, the actual decay breakup prediction can be improved.

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If you assume as input axioms: (1) QCD is correct; and (2) the OZI rule is universal for weakly coupled glue in disconnected Zweig diagrams where the disconnection is due to the creation or annihilation of new flavor(s) of quark(s), then the BNL/CCNY g/sub T/(2010), g/sub T/'(2220) and g/sub T/(2360) observed in ..pi../sup -/p ..-->.. phi phi n are produced by 1-3 primary glueballs. One or two broad primary glueballs could in principle break down the OZI suppression and mix with one or two quark states which accidentally have the same quantum numbers and nearly the same mass. However the simplest explanation of the rather unusual characteristics of our data is that we have found a triplet of J/sup PC/ = 2/sup + +/ glueball states. Since our input axioms are in good agreement with experiments and merely represent modern QCD practice, we have very probably discovered 1-3 J/sup PC/ = 2/sup + +/ glueballs. The iota(1440) and the theta(1700) observed in J/psi radiative decay are glueball candidates. The pros and cons of which are discussed briefly here. 41 references.

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This report covers the activities with regard to on-site customer irradiations as of the above date. The report covers the status of materials undergoing irradiation, awaiting disposition, material shipped during the month, and current status of all reactor test holes. The integrated exposure values are calculated in accordance with HW-62781, {open_quotes}Status Report Equations.{close_quotes} The integrated exposure reported is the average exposure received by the surrounding uranium columns. Conversion to exposure received by the sample is left to the customer.

This invention is comprised of a background-reducing x-ray multilayer mirror. A multiple-layer ``wavetrap`` deposited over the surface of a layered synthetic microstructure soft x-ray mirror optimized for reflectivity at chosen wavelengths is disclosed for reducing the reflectivity of undesired, longer wavelength incident radiation incident thereon. In three separate mirror designs employing an alternating molybdenum and silicon layered mirrored structure overlaid by two layers of a molybdenum/silicon pair anti-reflection coating, reflectivities of near normal incidence 133, 171, and 186 {Angstrom} wavelengths have been optimized, while that at 304 {Angstrom} has been minimized. The optimization process involves the choice of materials, the composition of the layer/pairs as well as the number thereof, and the distance therebetween for the mirror, and the simultaneous choice of materials, the composition of the layer/pairs, their number and distance for the ``wavetrap.``

The operation of a Priest Rapids dam is stated to necessitate river flow manipulation varying from 25,000 cfs to 120,000 cfs in the winter months of a critical water year. The low flow may persist for periods of six hours daily, and the expected daily average low flow is 61,000 cfs. The possible effects of this on reactor operation and waste disposal to the Columbia River which are of the interest to the Radiological Sciences Department were reviewed by J.F. Honstead, R.E. Rostenbach, and R.F. Foster. These include radiation hazards in reactor area water treatment plants, reactor area drinking water contamination; increased river temperature; chromium pollution problems; effects on downstream river usage, and effects on aquatic life.

A synergistic supercritical extraction process was developed and its feasibility demonstrated using a semi-batch extraction process unit. The process was found to be effective in selectively cleaning organic sulfur from Ohio coals. Optimal case involved a mixture of CO{sub 2}, H{sub 2}O, and CH{sub 3}OH, and the removal of organic sulfur ranged from 35 to 55%. Combined with pyrite and mineral matter removal by gravity, the resulting coals would have 20--30% increased heating values and SO{sub 2} emissions would be down to 1.2--1.5 pounds per million Btu, thus meeting compliance requirements. Estimated cleaning cost including pyrite removal is $25 to 45 per ton. The most important cost factor is the operation at high pressures.