The use of a two-stage concentrator with a fresnel lens primary and a non-imaging dielectric totally internally reflecting secondary, has unique advantages for photovoltaic concentration. This new design has a much larger acceptance angle than the conventional lens-cell concentrating system. In the continuation of this research, an optimally designed prototype which employs a 13.6-cm diameter flat fresnel tons as the primary focusing device, a dielectric compound hyperbolic concentrator (DCHC) as secondary and a 1-cm diameter high-concentration cell for electricity conversion has been built, tested and analyzed. Measurements under sunlight show that it has an angular acceptance of [plus minus]3.6 degrees, which is dramatically better than the [plus minus]0.5 degree achievable without a secondary concentrator. This performance agrees well with theoretical ray-tracing predictions. The secondary shows an optical efficiency of (91[plus minus]2)% at normal incidence. Combining with the primary fresnel tens which has an optical efficiency of (82[plus minus]2)%, tho two-stage system yields a total optical efficiency of (7l[plus minus]2)%. The measurement of the system electrical performance yielded a net electrical efficiency of 11.9%. No problems associated with non-uniform cell illumination were found, as evidenced by the excellent fill factor of (79[plus minus]2)% measured under concentration. The secondary geometrical properties and …

The use of a two-stage concentrator with a fresnel lens primary and a non-imaging dielectric totally internally reflecting secondary, has unique advantages for photovoltaic concentration. This new design has a much larger acceptance angle than the conventional lens-cell concentrating system. In the continuation of this research, an optimally designed prototype which employs a 13.6-cm diameter flat fresnel tons as the primary focusing device, a dielectric compound hyperbolic concentrator (DCHC) as secondary and a 1-cm diameter high-concentration cell for electricity conversion has been built, tested and analyzed. Measurements under sunlight show that it has an angular acceptance of {plus_minus}3.6 degrees, which is dramatically better than the {plus_minus}0.5 degree achievable without a secondary concentrator. This performance agrees well with theoretical ray-tracing predictions. The secondary shows an optical efficiency of (91{plus_minus}2)% at normal incidence. Combining with the primary fresnel tens which has an optical efficiency of (82{plus_minus}2)%, tho two-stage system yields a total optical efficiency of (7l{plus_minus}2)%. The measurement of the system electrical performance yielded a net electrical efficiency of 11.9%. No problems associated with non-uniform cell illumination were found, as evidenced by the excellent fill factor of (79{plus_minus}2)% measured under concentration. The secondary geometrical properties and the optimal two-stage design procedures for …

A system to analyze the chemical properties of a region of tissue located deep inside the human body without having to access it is proposed. The method is based on a high precision detection of x-rays or ..gamma..-rays (photons) from an external source Compton scattered from the tissue under inspection. The method provides chemical information of plane regions lying not too deep inside the body (<6 cm). The amount of radiation absorbed by the body is about the same as needed for a standard x-ray tomography. The exposure time is estimated to be shorter than 10 minutes. 37 refs., 13 figs.

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A simple model has been developed which can predict the magnetoresistance of copper as a function of initial purity, the extent of cold work and the presence of both irradiation produced point defects and the extended defects produced by annealing. The remaining area of uncertainty in a complete description of the response of superconducting magnets to irradiation-anneal cycles is the dependence of annealing on dose impurity concentration and cold-work.

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This report is a safeguards and security concept system review for the secure automated fabrication (SAF) and national liquid metal reactor (LMR) fuel programs.

The disks of Nd:doped phosphate glass in the amplifiers of the Nova laser contain platinum particles with sizes ranging from <5 ..mu..m (detection limit) to about 100 ..mu..m. The particle density varies from about 0.01 to 1.0 cm/sup -3/. These particles cause fractures when irradiated at fluences >2.5 J/cm/sup 2/ delivered in 1-ns, 1054-nm pulses. Under repeated irradiation at 5 to 7 J/cm/sup 2/, damage from small (<5 ..mu..m) particles asymptotically approaches a limiting size, but damage surrounding the larger particles grows steadily. The damage threshold fluence, 2.5 J/cm/sup 2/, corresponds to operation of Nova at one-half the desired output for pulse durations longer than 1 nsec. Operation at higher fluences causes accumulation of damage in the output amplifiers and requires replacement of the disks in those amplifiers on an accelerated schedule. 9 refs., 5 figs.

A simple, compact, high brightness x-ray source has recently been built. This source utilizes a commercially available, cylindrical geometry electron beam evaporator, which has been modified to enhance the thermal cooling to the anode. Cooling is accomplished by using standard, low-conductivity laboratory water, with an inlet pressure of less than 50 psi, and a flow rate of approx.0.3 gal/min. The anode is an inverted cone geometry for efficient cooling. The x-ray source has a measured sub-millimeter spot size (FWHM). The anode has been operated at 1 KW e-beam power (10 KV, 100 ma). Higher operating levels will be investigated. A variety of different x-ray lines can be obtained by the simple interchange of anodes of different materials. Typical anodes are made from easily machined metals, or materials which are vacuum deposited onto a copper anode. Typically, a few microns of material is sufficient to stop 10 KV electrons without significantly decreasing the thermal conductivity through the anode. The small size and high brightness of this source make it useful for step and repeat exposures over several square centimeter areas, especially in a research laboratory environment. For an aluminum anode, the estimated Al-K x-ray flux at 10 cms from the source …

Two E parallel to B end-loss-ion spectrometers (ELIS) are now making plasma measurements on Tandem Mirror Experiment-Upgrade (TMX-U). One instrument is mounted on each end of this open-ended tandem-mirror machine. These spectrometers observe plasma losses along magnetic-field lines. They operate reliably and with a minimum of attention during an experimental run. Their data, which are quickly acquired and analyzed, help guide the experimental sequence. The parallel electric and magnetic fields separate the end-loss ions according to mass (D/sup +/ and H/sup +/) and energy. Each spectrometer detects ions with an array of 128 flat collector plates that are made from copper-coated G10 epoxy fiberglass, normally used for printed-circuit boards. The ELIS diagnostic system produces a wealth of experimental information, including data on peak plasma potential, central-cell ion temperature, potentials in the thermal-barrier region, axial confinement and ion-end-loss plugging, energetic-electron losses, and hydrogen/deuterium concentrations. 6 refs., 5 figs.

We have made preliminary neutron-capture cross-section calculations of the Hauser-Feshbach type for the isotopes /sup 144/Sm, /sup 145/Sm, and /sup 145/Pm to investigate the production of radioactive /sup 145/Pm by neutron capture on the stable isotope /sup 144/Sm. The calculations were made for incident neutron energies from 2.5 MeV to about 1/sup -4/ or 10/sup -5/ MeV, wherever the first unbound resonance was estimated to occur in each case. At that energy, the calculated value was reduced by a somewhat arbitrary factor, and the excitation function extended down to thermal energy using a (E/sub n/)/sup -1/2/ energy dependence. Since very large uncertainties are associated with the position and magnitude of the first unbound resonance and the subsequent extrapolation back to thermal energy, the cross sections in this low-energy region should not be considered more accurate than +- a factor of 10. For incident neutron energies above each step, the calculations represent an average through the separated and overlapping resonance regions and may be accurate to better than +- a factor of 2. 18 refs., 7 figs., 5 tabs.

The purpose of this report is to show the results of enlarging the liquid argon vessel and moving the heavy supports by a varying magnitude less than or equal to 6 inches. In order to accomplish this, the center of gravity of the entire calorimeter had to be calculated, which includes: the center of gravity of the liquid argon vessel, the modules and the argon. Enlarging the cryostat for the endcap calorimeter and moving the rear supports along with it results in different load distributions on each support. By taking moments and finding these loads one can plot the loads on each support versus the enlargement of the cryostat and movement of the rear supports. This plot is shown in figures 2 and 3 for an empty and filled endcap respectively. The graph of weight vs. length of the vessel enlargement shows a significant decrease in the load that the heavy support experiences as the vessel gets larger, therefore the stress in the member decreases.

These proceedings describe the workshop of the Topical Meeting on Small Scale Geothermal Power Plants and Geothermal Power Plant Projects. The projects covered include binary power plants, rotary separator, screw expander power plants, modular wellhead power plants, inflow turbines, and the EPRI hybrid power system. Active projects versus geothermal power projects were described. In addition, a simple approach to estimating effects of fluid deliverability on geothermal power cost is described starting on page 119. (DJE-2005)

This report summarizes efforts made by the Seismological Laboratory toward the detection and delineation of shallow crustal zones in the western Great Basin, and toward the development of methods to accomplish such detection. The work centers around the recently-active volcanic center near Long Valley, California. The work effort is broken down into three tasks: (1) network operations, (2) data analysis and interpretation, and (3) the study of shallow crustal amomalies (magma bodies). Section (1) describes the efforts made to record thousand of earthquakes near the Long Valley caldera, and focusses on the results obtained for the November 1984 round Valley earthquake. Section (2) describes the major effort of this contract, which was to quantify the large volume of seismic data being recorded as it pertains to the goals of this contract. Efforts described herein include (1) analysis of earthquake focal mechanisms, and (2) the classification, categorization, and interpretation of unusual seismic phases in terms of reflections and refractions from shallow-crustal anomalous zones. Section (3) summarizes the status of our research to date on the locations of magma bodies, with particular emphasis on a location corresponding to the map location of the south end of Hilton Creek fault. Five lines of …

The stability of high intensity beams has been a matter of some concern. While anti-proton operation uses beam currents of 10 a or less, it is sometimes useful to have proton beams with currents of the order of 1 ma and narrow (booster sized) momentum spreads. This note describes calculations of what can be expected for coasting beam instabilities and, in particular, the effect of the (high impedance) 53 MHz cavities. This note specifically does not describe transverse instabilities, bunched beam instabilities, or turbulence in the debunching process. The stability limit can be calculated using standard formulae (van der Meer CERN/PS/AA/80-4 and many others). The result of this calculation is the 'stability plot' shown in figure 1a. This calculation assumes a 1 ma beam with a {Delta}p ({sigma}) of 2 MeV/c. The curve (allowed impedance) scales inversely with beam current and {Delta}p{sup 2}. The momentum spread was assumed to be gaussian. Figures 1b and 1c are the same plot but with different scales. The interpretation of this plot is that if the impedance of any device (or devices) is outside this curve, then the assumed beam distribution is unstable. More rigorously one can make a so-called 'Nyquist plot' where one …

Information compiled in 1985 while assessing the environmental impact of radionuclides previously discharged with aqueous releases from the Rancho Seco Nuclear Power Generating Plant is presented. In October 1984, the quantities of gamma-emitting radionuclides in water discharged to Clay Creek from the plant were reduced below operationally defined detection limits for liquid effluents. However, radionuclides previously discharged persist in the downstream environment and are found in many aquatic dietary components. /sup 134/Cs and /sup 137/Cs are the primary gamma-emitting radionuclides detected in the edible flesh of different fish, crayfish, and frogs. Coefficients for exponential equations are generated, from a least square analysis, that relate the change in concentration of /sup 137/Cs in fish to distance downstream and time between March and October 1985. Concentrations of /sup 137/Cs in surface creek sediments also decreased in the downstream direction much in the same manner as concentrations decreased in fish. However, there was no significant difference in the radiocesium concentrations in surface sediements collected from comparable locations during both 1984 and 1985.

As anionic species, both Tc-99 and I-129 are expected to be mobile in the soils beneath the burial ground. These two isotopes were analyzed in groundwater collected from research wells screened in the tritium plume leaving the burial ground. The maximum observed concentrations of 22 pCi/L of Tc-99 and 12 pCi/L of I-129 in the plume wells are above background levels and confirm the mobility of these species. The earlier measurements included in this report have been reported before.1,2 The data indicate that the I-129 concentrations may be increasing with time. Because of the long time (greater than one year) involved in obtaining results for these ultra low-level analyses, this work included analysis of only a few wells inside the burial ground. This limited selection of wells does not permit a mapping of the groundwater concentration isopleths.

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A finite element model of the CC cryostat was used to investigate the stresses resulting in this structure under internal pressure (30 psi at the top of the vessel increasing linearly to 40 psi at the bottom) and weight loadings. Figures 1 and 2 show the model and relevant physical dimensions. The results are given in Table I. The stresses were extracted. from the nodal stress output for individual elements. The variation of stress over the element is some indication of mesh adequacy in the absence of additional results from a finer mesh. Based on this variation, the stresses output for the central cylinder and head appear to be quite good. The nodal stresses vary about 15% within the most highly stressed elements. The maximum stresses in the outer cylinder occur in the element defined by the four nodes used for support. Stresses within this element vary by a factor of {approx}2. It is fair to say that no detailed information on stresses in the shell at the support is available with this mesh. However, outer shell stresses away from the supports are well within the limits for SS 304 as given by Section VIII, Division 2, Appendix 4. A …

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This is the minority report on the decision to use local ganging in the central calorimeter and major portions of the end cap calorimeters. The method not chosen for the readout is distant ganging. This method requires that the signal from each pad be carried to the outer radial edge of the board. There the signals from successive boards are connected together in parallel(ganged). From there the signal is carried to the cryostat port. All of the procedures needed to effect this design are known at this time. The line connecting each pad to the outer edge of its board can be produced by routing the line onto the readout board when the pads are routed. The lines are designed to be .007 inches wide with .008 inch spacings between lines. Lines of these dimension have been produced at Fermi Lab with very little difficulty. Three lines each 50 feet long were cut with out a break or short on the first attempt using the Fermi Gerber router. The connection from the lead to ganging cable is made with lands at the outer edge of the board. The ganging cable is created by layering copper and mylar. The first surface …

Even though peripheral heavy-ion collisions are less violent than their central counterparts, the large energy exchange between the reactants often leaves the primary products in excited particle-unstable states whose subsequent decay leads to 3 or more nuclei emerging in the final exit channel. These post-reaction, predominantly sequential de-excitation processes can sometimes provide interesting structural information about the parent nuclei. In fact, provided these processes are well understood, one can employ them as probes for studying initial properties of the fragments. This report discusses results of two experiments that deal with (1) nonstatistical, rare decay modes of the projectile, and (2) internal excitation energy of the projectile- and target-like fragments in peripheral collisions. The physics addressed in each is different, but the experimental and data-analysis techniques are so similar that it is relevant to join them together.