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F2 phenomenological test on fuel motion (Interim report). [LMFBR]

Description: TREAT F-series tests are being conducted to provide data on fuel motion at accident power levels from one to about ten times design for use in development of fuel motion models. Test F2 was conducted to evaluate motion of high power fuel in a hypothetical LMFBR unprotected TUC (transient undercooling) accident. Fuel and fuel-boundary conditions following coolant boiling and dryout under TUC conditions are achieved in each F-series test with a single fuel element surrounded by a nuclear heated wall in a dry test capsule. Test F2 was conducted with a low burnup but restructured fuel element to investigate the effect of fuel vapor pressure on fuel motion. Results are presented and discussed.
Date: September 1, 1976
Creator: Palm, R. G.; Fink, C. L.; Stewart, R. R.; Gehl, S. M. & Rothman, A. B.
Partner: UNT Libraries Government Documents Department

Heavy particle searches using main ring on doubler collisions

Description: A versatile, large angle spectrometer system is described which is capable of performing a variety of sensitive searches for new heavy particles which may emerge from the main ring on doubler collisions. Searches for long-lived heavy particles should be capable of reaching cross sections comparable to limits obtained in ISR experiments but would be sensitive to masses up to a factor of 10 larger. It seems likely that at least two high luminosity colinear intersections will be needed in order to perform the W-search and heavy particle search experiments early in the collider program. (SDF)
Date: September 1, 1976
Creator: Ayres, D. S. & Diebold, R.
Partner: UNT Libraries Government Documents Department

High single-step enrichment of rare stable isotopes by ion laser formaldehyde photo-predissociation

Description: Very high single-step enrichment of deuterium, carbon-13, oxygen-17, and oxygen-18 has been achieved by photo-predissociation of formaldehyde with tunable near-ultraviolet ion lasers. Insertion of an intracavity etalon permitted tuning the XeIII 345.425nm ion laser transition over 10 GHz and the NeII transitions at 337.824nm and 332.375nm over 16 GHz to permit optimized isotopic selectivity of each formaldehyde isotope having absorption within the ion laser tuning range. Natural abundance deuterium was enriched 60-fold at 345nm to yield hydrogen gas with 1.6 percent HD, and 180-fold enrichment of deuterium as D/sub 2/ was achieved at 332nm. Substituting neon-22 blue-shifted laser emission 7 GHz to permit 33-fold enrichment of natural abundance carbon-13 to yield 29 percent /sup 13/CO photoproduct. D/sub 2/CO was used to achieve 44-fold oxygen-18 enrichment at 332nm and 27-fold oxygen-17 enrichment at 338nm also using the neon-22 ion laser. Radical production in D/sub 2/CO is less than 1 percent at 332nm. Isotope scrambling is 24 percent for C-13 using H/sub 2//sup 13/CO at 332nm, 4 percent for 0-18 using D/sub 2/C/sup 18/O at 332nm, and 9 percent for 0-17 using D/sub 2/C/sup 17/O at 338nm.
Date: September 1, 1976
Creator: Marling, J. B.
Partner: UNT Libraries Government Documents Department

Holographic interferometry of laser fusion targets at 2660 A

Description: Holographic interferometry at 2660 A has been used to study plasma blowoff from 80 micron diameter laser fusion targets. Scale lengths of 11 microns, measured with 1 micron spatial resolution, are recorded at 7 x 10/sup 20/ e/cc after 800 psec of hydrodynamic expansion. These results suggest much steeper density gradients at peak irradiation intensity. The observed fringe pattern is strongly dependent on interferometric imaging, as expected for strong transverse gradient refractive media. Significant interpretive errors, which might occur in a single image classical interferometer, are avoided with this holographic technique.
Date: September 1, 1976
Creator: Coleman, L. W.; Attwood, D. T. & Sweeney, D. W.
Partner: UNT Libraries Government Documents Department

Beam diagnostics on ARGUS

Description: Performance of laser fusion targets depends critically on the characteristics of the incident beam. The spatial distribution and temporal behavior of the light incident on the target varies significantly with power, with choice of beam spatial profile and with location of spatial filters. On each ARGUS shot we photograph planes in the incident beams which are equivalent to the target plane. Array cameras record the time integrated energy distributions and streak cameras record the temporal behavior. Computer reduction of the photographic data provides detailed spatial energy distributions, and instantaneous power on target vs. time. Target performance correlates with the observed beam characteristics.
Date: September 22, 1976
Creator: MacQuigg, D. R. & Speck, D. R.
Partner: UNT Libraries Government Documents Department

Conceptual design study for a laser fusion hybrid

Description: Lawrence Livermore Laboratory and Bechtel Corporation have been involved in a joint effort to conceptually design a laser fusion hybrid reactor. The design which has evolved is a depleted-uranium fueled fast-fission blanket which produces fissile plutonium and electricity. A major objective of the design study was to evaluate the feasibility of producing fissile fuel with laser fusion. This feasibility evaluation was carried out by analyzing the integrated engineering performance of the complete conceptual design and by identifying the required laser/pellet performance. The performance of the laser fusion hybrid has also been compared to a typical fast breeder reactor. The results show that the laser fusion hybrid produces enough fissile material to fuel more than six light water reactors (LWR's) of equivalent thermal power while operating in a regime which requires an order of magnitude less laser and pellet performance than pure laser fusion. In comparison to a fast breeder reactor the hybrid produces 10 times more fissile fuel. An economic analysis of the design shows that the cost of electricity in a combined hybrid-LWR scenario is insensitive to the capital cost of the hybrid, increasing by only 20 to 40 percent when the capital cost of the hybrid ranges from 2 to 3 times more than an LWR.
Date: September 1, 1976
Creator: Maniscalco, J. A.
Partner: UNT Libraries Government Documents Department

Is plutonium really necessary

Description: Not all activities associated with nuclear power contribute equally to proliferation potential, but some fuel-cycle activities (i.e., reprocessing) are considered too dangerous to be permitted in non-weapons countries. This paper assesses the feasibility of keeping Pu out of the nuclear fuel cycle. It is pointed out that there is no technical necessity of using Pu as nuclear fuel so long as /sup 235/U is available. Analysis of the economics of recycling spent fuel products in LWRs in the U.S. shows that the net economic benefit of recycle is uncertain and might even be negative; it will have an insignificant effect on the cost of nuclear power. It is argued that reprocessing of spent fuel be deferred until recycle in LWRs can be shown to yield economic benefits sufficiently large to compensate for the risks, or the viability of the breeder as an important commercial source of power has been demonstrated. According to the low estimate of U requirements, the world would have enough U resources well into the 21st century, although if the high estimate is used, the world would exhaust its reserves by the year 2000. Evidence indicates that nuclear power will grow more slowly than the forecasts of the nuclear advocates. Thus, there may be no need for an early decision to undertake recycling, and research on breeder development can proceed at a slower rate. (DLC)
Date: September 9, 1976
Creator: Taylor, V.
Partner: UNT Libraries Government Documents Department

Decay heat of /sup 235/U fission products by beta- and gamma-ray spectrometry

Description: The fast-rabbit facilities of the ORRR were used to irradiate 1- to 10-..mu..g samples of /sup 235/U for 1, 10, and 100 s. Released power is observed using nuclear spectroscopy to permit separate observations of emitted ..beta.. and ..gamma.. spectra in successive time intervals. The spectra were integrated over energy to obtain total decay heat and the ..beta..- and ..gamma..-ray results are summed together. 10 fig, 2 tables. (DLC)
Date: September 1, 1976
Creator: Dickens, J. K.; Love, T. A.; McConnell, J. W. & Peelle, R. W.
Partner: UNT Libraries Government Documents Department

Plasma experiments with 1. 06. mu. m lasers at the Lawrence Livermore Laboratory

Description: Irradiation experiments were performed with the two beam Nd:YAG glass laser systems, Janus(approximately less than 40 J/100 psec, approximately 0.4 TW), Cyclops (approximately less than 70 J/100 psec, approximately 0.7 TW), and Argus (approximately less than 70 J, 35 psec, approximately 2 TW). Two classes of targets have been used, glass microshells (approximately 40 to 120 ..mu..m diameter x approximately 0.75 ..mu..m wall thickness) filled with an equimolar DT mixture and disks (approximately 160 to 600 ..mu..m diameter x approximately 10 ..mu..m thick) of several compositions. The targets were supported in vacuum (pressure approximately less than 10/sup -5/ Torr) by thin glass stalks. This paper reports results related to the propagation, absorption and scattering of laser light by both spherical and planar targets. The absorption measurements cannot be explained using only inverse Bremsstrahlung. The scattered light and the plasma energy are polarization dependent, which is evidence of resonance absorption. The x-ray spectra are characterized by a thermal and a suprathermal distribution. The ''temperature'' of the hot x-rays is given by theta/sub H/ approximately equals I./sup 3/-./sup 4/ depending on the target material. Evidence is also presented which indicates that the laser radiation pressure is producing density steepening in the region of the critical density with n/sub cr/(delta n/delta x)/sup -1//sub cr/ approximately sigma(1 ..mu..m) and in some cases plasma filamentation is observed.
Date: September 19, 1976
Creator: Ahlstrom, H. G.; Holzrichter, J. F.; Manes, K. R.; Storm, E. K.; Haas, R. A.; Phillion, D. W. et al.
Partner: UNT Libraries Government Documents Department

Laser fusion burn diagnostics using several. cap alpha. -time-of-flight spectrometers

Description: A more compact ..cap alpha..-particle time-of-flight spectrometer using a permanent field deflection magnet has been developed for laser fusion burn diagnostics. The spectrometer is being used to measure the number and energy distribution of fusion-produced ..cap alpha.. particles emitted from laser implosions of DT gas contained in glass microshells. It is planned to view the target from different angles using several spectrometers simultaneously. Comparison of energy loss and energy broadening vs angle can yield information concerning the nature of compression and subsequent burn. Results from target experiments on the LLL ARGUS laser facility are present.
Date: September 30, 1976
Creator: Tirsell, K. G.; Catron, H. C.; Glaros, S. S. & Slivinsky, V. W.
Partner: UNT Libraries Government Documents Department

Laser experiments on KrCl and ArF /sup 2/. sigma. --/sup 2/. sigma. transitions

Description: The laser and fluorescence output of KrCl and ArF were measured and the effect of the gas mixture on the laser output was determined. Possible mechanisms for the effects observed are suggested. (JSR)
Date: September 9, 1976
Creator: Murray, J. R. & Powell, H. T.
Partner: UNT Libraries Government Documents Department

Laser fusion burn diagnostics using several. cap alpha. -time-of-flight spectrometers

Description: A more compact ..cap alpha..-particle time-of-flight spectrometer using a permanent field deflection magnet has been developed for laser fusion burn diagnostics. The spectrometer is being used to measure the number and energy distribution of fusion-produced ..cap alpha.. particles emitted from laser implosions of DT gas contained in glass microshells. It is planned to view the target from different angles using several spectrometers simultaneously. Comparison of energy loss and energy broadening vs angle can yield information concerning the symmetry of compression and subsequent burn. Results from target experiments on the LLL ARGUS laser facility are present.
Date: September 30, 1976
Creator: Tirsell, K. G.; Catron, H. C.; Glaros, S. S. & Slivinsky, V. W.
Partner: UNT Libraries Government Documents Department

Scattered light evidence for short density heights near critical density in laser-irradiated plasmas

Description: Experimental evidence is presented of a steepened electron density profile near critical density obtained from studying the time-integrated scattered light from targets illuminated by linearly polarized, 1.06 ..mu.. light. Both 10 ..mu.. thick disks and DT-filled glass microshells were irradiated by light focused by f/1 or f/2.5 lenses in one and two-beam experiments, respectively. From the dependence of the asymmetry of the scattered light about the beam axis upon the scattering angle, scale lengths on the order of one micron are inferred. Scale lengths have also been deduced from measurements on the polarization state of the reflected light. Both analytic and numerical results are presented to show how the polarization state varies with the incidence angle and the scale length.
Date: September 15, 1976
Creator: Phillion, D. W.; Lerche, R. A.; Rupert, V. C.; Haas, R. A. & Boyle, M. J.
Partner: UNT Libraries Government Documents Department

Measurement of the widths of emission lines from laser produced plasmas

Description: The targets used for the creation of laser produced plasmas often contain sodium, silicon and other period 3 elements. Temperature and density information can be inferred from detailed study of the characteristic radiation from these elements. The resolution capabilities of crystal spectrographs designed to look at such target radiation are discussed. Data from several types of spectrographs are compared. The fine structure of the hydrogen and helium-like silicon lines are used to illustrate spectrograph resolution. A spectrograph for examining weak characteristic radiation near 1 keV due to plasma which has been compressed with a spherical irradiation system is discussed.
Date: September 15, 1976
Creator: Richards, L. M.; Slivinsky, V. W.; Eckels, J. D. & Glaros, S. S.
Partner: UNT Libraries Government Documents Department

Water supply dilemmas of geothermal development in the Imperial Valley of California

Description: There are four known geothermal resource areas in the Imperial Valley that have a combined potential of over 4,000 megawatts of electrical energy for 25 years. The water resources available to support geothermal energy development are imported Colorado River water, agricultural waste waters, Salton Sea water, and ground water. In addition, geothermal power plants can produce their own cooling water in the form of steam condensate. Nevertheless, the relatively high water requirements of geothermal facilities along with a series of real and potential constraints may cause water supply dilemmas involving both the acquisition and use of cooling water. Important constraints are institutional policies, water supply costs, technical problems, and impacts upon the Salton Sea. These constraints and related dilemmas are examined in light of relevant information on the valley's water resources, geothermal resources and energy technologies, cooling water requirements, and water supply options.
Date: September 15, 1976
Creator: Layton, D. W.
Partner: UNT Libraries Government Documents Department

Vacuum engineering for fusion research and fusion reactors

Description: The following topics are described: (1) surface pumping by cryogenic condensation, (2) operation of large condensing cryopumps, (3) pumping for large fusion experiments, and (4) vacuum technology for fusion reactors. (MOW)
Date: September 7, 1976
Creator: Pittenger, L. C.
Partner: UNT Libraries Government Documents Department

Review of direct energy conversion for fusion reactors

Description: The direct conversion to electrical energy of the energy carried by the leakage plasma from a fusion reactor and by the ions that are not converted to neutrals in a neutral-beam injector is discussed. The conversion process is electrostatic deceleration and direct particle collection as distinct from plasma expansion against a time-varying magnetic field or conversion in an EXB duct (both MHD). Relatively simple 1-stage plasma direct converters are discussed which can have efficiencies of about 50 percent. More complex and costly (measured in $/kW) 2-, 3-, 4-, and 22-stage concepts have been tested at efficiencies approaching 90 percent. Beam direct converters have been tested at 15 keV and 2 kW of power at 70 +- 2 percent efficiency, and a test of a 120-keV, 1-MW version is being prepared. Designs for a 120-keV, 4-MW unit are presented. The beam direct converter, besides saving on power supplies and on beam dumps, should raise the efficiency of creating a neutral beam from 40 percent without direct conversion to 70 percent with direct conversion for a 120-keV deuterium beam. The technological limits determining power handling and lifetime such as space-charge effects, heat removal, electrode material, sputtering, blistering, voltage holding, and insulation design, are discussed. The application of plasma direct converters to toroidal plasma confinement concepts is also discussed.
Date: September 20, 1976
Creator: Barr, W. L. & Moir, R. W.
Partner: UNT Libraries Government Documents Department

Response of ultrafast scintillators

Description: Measurements of the properties of subnanosecond, quenched NE111 plastic scintillators with various concentrations of acetophenone and benzophenone are presented. These quenching agents have been found to very significantly decrease the NE111 decay time. Measurements are made using UV and laser produced x-ray radiations. The scintillations are detected using a visible streak camera with 10 ps resolution. Measurements of: (1) 10-90 percent rise time, (2) FWHM, (3) decay time, (4) relative scintillator efficiencies, and (5) amplitudes vs. time measurements of the long decay component are presented. All temporal measurements are obtained from a gold cathode ultrafast x-ray streak camera, and the detailed x-ray energy spectrum above 1 keV is also measured using an array of x-ray PIN diodes equipped with the appropriate K-edge filters. Details of the experimental measurements are discussed and anticipated applications are included.
Date: September 1, 1976
Creator: Cheng, J. C.; Lerche, R. A.; Tripp, G. R. & Coleman, L. W.
Partner: UNT Libraries Government Documents Department

Particle and x-ray energy measurements in laser-plasma interaction experiments

Description: The energy carried by particles and low energy x-rays resulting from irradiation of targets with .5 to 1 TW, 1.06 ..mu..m lasers has been measured. The energy distributions were obtained from measurements at discrete locations using calorimeters and work is in progress to obtain them over a hemisphere with a thermal imaging system. Azimuthal symmetry and polar distributions for different focusing schemes have been determined. The data have been integrated to obtain the absorbed energy and these values compared to box calorimetry and optical energy balance. The relative emission of low energy x-rays from different Z materials can be obtained by comparing these data to charge collector data. Such comparisons also showed that the effective ion charge can be as low as a factor of two below the completely ionized state. The existence of low charge state ions has since been confirmed with high resolutions spectrometers.
Date: September 24, 1976
Creator: Rupert, V. C.; Gunn, S. R.; Holzrichter, J. F.; Glaros, S. S.; Severyn, J. R. & Lee, P.
Partner: UNT Libraries Government Documents Department

Effects of density gradient modification on fluid instability in thermonuclear micro-implosions

Description: The presence of hydrodynamic fluid instability at the ablation surface puts constraints on the kinds of targets, surface finish, and energy sources that one can use for thermonuclear micro-implosions. If Taylor-like modes grow at near the classical value, one is limited to low aspect ratio shells and surface finishes of 10-100 A. These surface finish requirements can be reduced by 1 to 2 orders of magnitude by exploiting density gradient modification techniques to obtain a shallow density gradient at the ablation surface. For laser driven targets, the gradient is achieved by utilizing suprathermal electrons with a high energy ''get lost'' region to eliminate severe preheat problems. For charged particle sources, the reduction is achieved by introducing an energy spread on the driving source.
Date: September 24, 1976
Creator: Lindl, J. D.; Bangerter, R. O.; Nuckolls, J. H.; Mead, W. C. & Thomson, J. J.
Partner: UNT Libraries Government Documents Department

Scattered light evidence for short density scale heights near critical density in laser-irradiated plasmas

Description: Experimental evidence is presented of a steepened electron density profile near critical density obtained from studying the time-integrated scattered light from targets illuminated by linearly polarized, 1.06 ..mu.. light. Both 10 ..mu.. thick disks and DT-filled glass microshells were irradiated by light focused by f/1 or f/2.5 lenses in one and two-beam experiments, respectively. From the dependence of the asymmetry of the scattered light about the beam axis upon the scattering angle, we infer scale lengths on the order of one micron. Scale lengths have also been deduced from measurements on the polarization state of the reflected light. Both analytic and numerical results are presented to show how the polarization state varies with the incidence angle and the scale length.
Date: September 15, 1976
Creator: Phillion, D. W.; Lerche, R. A.; Rupert, V. C.; Haas, R. A. & Boyle, M. J.
Partner: UNT Libraries Government Documents Department

First wall studies of a laser-fusion hybrid reactor design

Description: The design of a first wall for a 20 MW thermonuclear power laser fusion hybrid reactor is presented. The 20 mm thick graphite first wall is located 3.5 m from the DT microexplosion with a thermonuclear yield of 10 MJ. Estimates of the energy deposition, temperature, stresses, and material vaporized from the first wall due to the interaction of the x-rays, charged particle debris, and reflected laser light with the graphite are presented, along with a brief description of the analytical methods used for these estimations. Graphite is a viable first wall material for inertially-confined fusion reactors, with lifetimes of a year possible.
Date: September 1, 1976
Creator: Hovingh, Jack
Partner: UNT Libraries Government Documents Department

Flash x-ray. [Nondestructive testing of material that is moving or changing very rapidly]

Description: The complementary techniques of flash x-ray radiography (FXR) and flash x-ray diffraction (FXD) provide access to a unique domain in nondestructive materials testing. FXR is useful in studies of macroscopic properties during extremely short time intervals, and FXD, the newer technique, is used in studies of microscopic properties. Although these techniques are similar in many respects, there are some substantial differences. FXD generally requires low-voltage, line-radiation sources and extremely accurate timing; FXR is usually less demanding. Phenomena which can be profitably studied by FXR often can also be studied by FXD to permit a complete materials characterization.
Date: September 7, 1976
Creator: Johnson, Q. & Pellinen, D.
Partner: UNT Libraries Government Documents Department

Operation and control of high density tokamak reactors

Description: The incentive for high density operation of a tokamak reactor was discussed. It is found that high density permits ignition in a relatively small, moderately elongated plasma with a moderate magnetic field strength. Under these conditions, neutron wall loadings approximately 4 MW/m/sup 2/ must be tolerated. The sensitivity analysis with respect to impurity effects shows that impurity control will most likely be necessary to achieve the desired plasma conditions. The charge exchange sputtered impurities are found to have an important effect so that maintaining a low neutral density in the plasma is critical. If it is assumed that neutral beams will be used to heat the plasma to ignition, high energy injection is required (approximately 250 keV) when heating is accompished at full density. A scenario is outlined where the ignition temperature is established at low density and then the fueling rate is increased to attain ignition. This approach may permit beams with energies being developed for use in TFTR to be successfully used to heat a high density device of the type described here to ignition.
Date: September 13, 1976
Creator: Attenberger, S. E. & McAlees, D. G.
Partner: UNT Libraries Government Documents Department