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Optical components for the Nova laser (open access)

Optical components for the Nova laser

In addition to its other characteristics, the Nova Laser Fusion facility may well be the largest precision optical project ever undertaken. Moreover, during the course of construction, concurrent research and development has been successfully conducted, and has resulted in significant advances in various technical areas, including manufacturing efficiency. Although assembly of the first two beams of Nova is just commencing, the optical production, including construction of the special facilities required for many of the components, has been underway for over three years, and many phases of the optical manufacturing program for the first 10 beams will be completed within the next two years. On the other hand, new requirements for second and third harmonic generation have created the need to initiate new research and development. This work has been accomplished through the enormous cooperation DOE/LLNL has received from commercial industry on this project. In many cases, industry, where much of the optical component research and development and virtually all of the manufacturing is being done, has made substantial investment of its own funds in facilities, equipment, and research and development, in addition to those supplied by DOE/LLNL.
Date: May 17, 1982
Creator: Wallerstein, E.P.; Baker, P.C. & Brown, N.J.
System: The UNT Digital Library
Models for Type I supernovae (open access)

Models for Type I supernovae

Two rather disjoint scenarios for Type I supernovae are presented. One is based upon mass accretion by a white dwarf in a binary system. The second involves a star having some 8 to 10 times the mass of the sun which may or may not be a solitary star. Despite the apparent dissimilarities in the models it may be that each occurs to some extent in nature for they both share the possibility of producing substantial quantities of /sup 56/Ni and explosions in stars devoid of hydrogen envelopes. These are believed to be two properties that must be shared by any viable Type I model.
Date: June 17, 1980
Creator: Woosley, S. E.; Weaver, T. A. & Taam, R. E.
System: The UNT Digital Library
A high-fluence fusion neutron source (open access)

A high-fluence fusion neutron source

A conceptual design of a D-T fusion facility for continuous production of 14-MeV neutron wall loading from 5 to 10 MW/m/sup 2/ at the plasma surface is presented. In this design, D-T neutrons are produced in a linear, two-component plasma formed by neutral beam irradiation of a fully ionized warm plasma target. The beam energy, which is deposited in the center, is transferred to the warm plasma mainly by electron drag and is conducted along the target plasma column to end regions where it is absorbed in neutral gas at high pressure. The target plasma is operated in a regime where electron thermal conduction along the column is the controlling energy-loss process. The loss rate is minimized by adjusting the diameter and length of the plasma column. A substantial gradient in T/sub e/ along the column results in recombination of the plasma to gas in the end-regions before impact on the end walls. The resultant hot gas is cooled by contact with large-area heat exchangers. In this way, the large steady-state heat load from the injected neutral beams is diffused and removed at tolerable heat flux levels. The reacting plasma is essentially an extrapolation of the 2XIIB high-..beta.. plasma to …
Date: February 17, 1988
Creator: Coensgen, F. H.; Casper, T. A.; Correll, D. L.; Damm, C. C.; Futch, A. H.; Logan, B. G. et al.
System: The UNT Digital Library
Control of radioactive material transport in sodium-cooled reactors (open access)

Control of radioactive material transport in sodium-cooled reactors

The Radioactivity Control Technology (RCT) program was established by the Department of Energy to develop and demonstrate methods to control radionuclide transport to ex-core regions of sodium-cooled reactors. This radioactive material is contained within the reactor heat transport system with any release to the environment well below limits established by regulations. However, maintenance, repair, decontamination, and disposal operations potentially expose plant workers to radiation fields arising from radionuclides transported to primary system components. This paper deals with radioactive material generated and transported during steady-state operation, which remains after /sup 24/Na decay. Potential release of radioactivity during postulated accident conditions is not discussed. The control methods for radionuclide transport, with emphasis on new information obtained since the last Environmental Control Symposium, are described. Development of control methods is an achievable goal.
Date: March 17, 1980
Creator: Brehm, W. F.
System: The UNT Digital Library
Early Admission to College for Bright Students (open access)

Early Admission to College for Bright Students

Article discussing the early admission to college programs, including the Texas Academy of Mathematics and Science.
Date: May 17, 1989
Creator: Cromer, Alan
System: The UNT Digital Library
Monopole strength as a probe of nuclear shape mixing (open access)

Monopole strength as a probe of nuclear shape mixing

The monopole strength, MS, within a single set of nuclear shape excitations is compared with the MS between different shapes. After misconceptions are pointed out concerning the spin dependence of B(E2) values, MS properties are juxtaposed with gamma-ray and beta-decay properties of /sup 70/Se, /sup 96/Zr, /sup 102/Pd, and the N = 60 isotones to illustrate the utility of combined investigations and evidence is given for the observation of a two-phonon octupole multiplet. Finally, consideration is given to the dominance of the /sup 3/S/sub 1/ force in producing deformation in the N > 50 1g nuclei. 23 refs., 4 figs.
Date: August 17, 1987
Creator: Meyer, R.A.
System: The UNT Digital Library
Hadronic production of J/sup PC/ = 2/sup + +/ glueballs (open access)

Hadronic production of J/sup PC/ = 2/sup + +/ glueballs

An OZI suppressed channel with variable mass, namely the reaction ..pi../sup -/p ..-->.. phi phi n, has been used as a filter which allows resonating gluons or glueballs to pass, while strongly rejecting conventional quark-built hadronic states. The breakdown of the OZI suppression signals a glueball. Glueball mass and particle width estimates are discussed. Reasons why g/sub T/'s have not been seen in other channels, particularly the decay of J/psi, are considered. 34 refs., 9 figs. (LEW)
Date: March 17, 1986
Creator: Lindenbaum, S. J.
System: The UNT Digital Library
ICF diagnostics. Revision 1 (open access)

ICF diagnostics. Revision 1

In the past several years there have been significant advances and accomplishments in the field of Inertial Confinement Fusion (ICF) research which are directly attributable to an active experimental program supported by the development and applications of sophisticated and specialized diagnostics instruments and techniques. The continued development of high temporal-and spatial-resolution diagnostics, although with a somewhat different technical emphasis than previously, is essential for maintaining progress in ICF. With the generation of inertial fusion drivers now becoming available progress toward higher density compression of fusion fuel will be attained at the expense of temperature, and consequently emissions from the targets will be limited. At the same time since the targets are being driven to higher density they are more opaque to the low-to-moderate energy x-rays (up to a few keV) and particles (alpha particles, protons, and knock-on charged particles) that have been utilized for diagnosing target performance.
Date: December 17, 1982
Creator: Coleman, L.W.
System: The UNT Digital Library
Status of the Lawrence Berkeley Laboratory and the Lawrence Livermore National Laboratory (LLNL) free electron laser (FEL). Revision 1 (open access)

Status of the Lawrence Berkeley Laboratory and the Lawrence Livermore National Laboratory (LLNL) free electron laser (FEL). Revision 1

A high-gain FEL experiment using the 10 kA, 4.5 MeV Experimental Test Accelerator (ETA) is described.
Date: November 17, 1983
Creator: Orzechowski, T. J.; Moebus, M. C.; Penko, F. A.; Prosnitz, D.; Rogers, D.; Chavis, C. S. et al.
System: The UNT Digital Library
Proceedings: special panel on geothermal model intercomparison study (open access)

Proceedings: special panel on geothermal model intercomparison study

Separate abstracts were prepared for five papers. Two papers were abstracted previously for EDB. Five panel responses to the project, three workshop session summaries, and conclusions drawn are also included in this report. (MHR)
Date: December 17, 1980
Creator: unknown
System: The UNT Digital Library
Positrons from supernova and the origin of the galactic-center positron-annihilation radiation (open access)

Positrons from supernova and the origin of the galactic-center positron-annihilation radiation

The emission of positrons from supernova ejecta is dicussed in terms of the galactic-center annihilation radiation. The positrons from the radioactive sequences /sup 56/Ni..-->../sup 56/Co..-->../sup 56/Fe are the most numerous source from supernova. Only type I supernova will allow a significant fraction to escape the expanding ejecta. For a neutron star model of a type I SN a fraction 4 x 10/sup -3/ of the escaped positron is enough to create the observed several year fluctuation of the annihilation radiation. The likelihood of this model is discussed in terms of other astrophysical evidence as well as the type I SN light curve.
Date: March 17, 1983
Creator: Colgate, S. A.
System: The UNT Digital Library
Workshop report on new directions in soft x-ray photoabsorption (open access)

Workshop report on new directions in soft x-ray photoabsorption

The Workshop Report integrates what was said at the Workshop on New Directions in Soft X-Ray Photoabsorption, which focused on the region from 100 eV to 10 keV. The report clarifies the current state of theory and experiment and identifies the opportunities which new theoretical methods and experimental facilities could be expected to provide. The understanding of photoabsorption (which requires experimental photoabsorption cross section data) is a key to understanding the properties and behavior of atoms, molecules and solids. The Workshop participants were forty-three physicists and quantum chemists, from twenty-four institutions in four countries, all interested in photoabsorption from different perspectives.
Date: September 17, 1984
Creator: Bartlett, R.; Del Grande, N.K.; Lindau, I.; Manson, S.; Merts, A.L. & Pratt, R.
System: The UNT Digital Library
Magnet technology for the Engineering Test Reactor (open access)

Magnet technology for the Engineering Test Reactor

The consideration for building an international Engineering Test Reactor emerged from the November 1985 Geneva Summit, in which President Reagan and Secretary Gorbachev called for the ''widest practical development of international cooperation'' in fusion. In parallel with the OTR design in the USSR, the FER in Japan, and the NET in Europe, the US has pursued the TIBER (Tokamak Ignition/Burn Experimental Reactor). This compact design of 3-m major radius is achievable because of high-current-density, radiation-tolerant magnets with nuclear heating rates up to 10 mW . cm/sup -3/. Full development of cable-in-conduit conductors (CICC) is seen as a credible path to achieve 40 A . mm/sup -2/ at fields of 12 T in the toroidal field (TF) coils and 14 T in the central poloidal field (PF) coils. Since neutron fluences of up to 10/sup 19/ n . cm/sup -2/ are expected in the TF coils, the unalloyed niobium-tin would be superior at 12 T. However, the central PF coil at 14 T is better shielded, so modified niobium tin would be advantageous. Polyimide insulation in the TF coils would withstand the equivalent 10/sup 10/) rads if loads in the winding pack are taken in compression. 13 refs., 7 figs., 2 …
Date: September 17, 1987
Creator: Henning, C. D. & Miller, J. R.
System: The UNT Digital Library
Mechanism of the optogalvanic effect in a hollow-cathode discharge (open access)

Mechanism of the optogalvanic effect in a hollow-cathode discharge

There are two significantly different mechanisms proposed for the origin of the optogalvanic effect in a hollow-cathode discharge: (1) laser excitation of atoms to higher electronic states leads to an increased cross section for electron impact ionization, with the result that the excited atom becomes ionized and the conductivity of the discharge increases; and (2) laser excitation of atoms to higher electronic states perturbs the equilibrium established between the electron temperature and the atomic excitation temperature. Superelastic collisions between the electrons and the laser-excited atoms restore the equilibrium, with the excess energy ending up in an increased electron temperature and therefore an increased conductivity of the discharge. Both mechanisms undoubtedly proceed simultaneously and what needs to be determined is their relative importance at different discharge conditions and different excitation conditions. This is important because laser isotope enrichment schemes have been proposed using selective excitation in a hollow-cathode discharge. In order for these schemes to work, (1) must be the predominant mechanism. We have measured the optogalvanic signal, concentration of uranium atoms, impedance of the discharge, and electron temperature as a function of the discharge current in a neon-filled uranium hollow-cathode discharge. The hollow cathode operating characteristics are used as input …
Date: June 17, 1983
Creator: Keller, Richard A.; Warner, Bruce E.; Zalewski, Edward F.; Dyer, P.; Engleman, Rolf, Jr. & Palmer, Byron A.
System: The UNT Digital Library
Projectile-power-compressed magnetic-field pulse generator (open access)

Projectile-power-compressed magnetic-field pulse generator

Design considerations and experimental results are presented of a compressed magnetic field pulsed energy source. A 100-mm-diameter, gun-fired projectile of approx. 2MJ kinetic energy was the input energy source. An initial magnetic field was trapped and compressed by the projectile. With a shorted load, a magajoule in a nanohenry was the design goal, i.e., 50 percent energy transformation from kinetic to magnetic. Five percent conversion was the highest recorded before gauge failure.
Date: March 17, 1983
Creator: Barlett, R.H.; Takemori, H.T. & Chase, J.B.
System: The UNT Digital Library
The LLNL HFTF (High-Field Test Facility): A flexible superconducting test facility for fusion magnet development (open access)

The LLNL HFTF (High-Field Test Facility): A flexible superconducting test facility for fusion magnet development

The High-Field Test Facility (HFTF) is a flexible and, in many ways, unique facility at Lawrence Livermore National Laboratory (LLNL) for providing the test capabilities needed to develop the superconducting magnet systems of the next generation fusion machines. The superconducting coil set in HFTF has been operated successfully at LLNL, but in its original configuration, its utility as a test facility was somewhat restricted and cryogenic losses were intolerable. A new cryostat for the coil set allows the magnet system to remain cold indefinitely so the system is available on short notice to provide high fields (about 11 T) inside a reasonably large test volume (0.3-m diam). The test volume is physically and thermally isolated from the coil volume, allowing test articles to be inserted and removed without disturbing the coil cryogenic volume, which is maintained by an on-line refrigerator. Indeed, with the proper precautions, it is even unnecessary to drop the field in the HFTF during such an operation. The separate test volume also allows reduced temperature operation without the expense and complication of subcooling the entire coil set (about 20-t cold mass). The HFTF has thus become a key facility in the LLNL magnet development program, where the …
Date: September 17, 1987
Creator: Miller, J. R.; Chaplin, M. R.; Leber, R. L. & Rosdahl, A. R.
System: The UNT Digital Library
Sodium/water pool-deposit bed model of the CONACS code. [LMFBR] (open access)

Sodium/water pool-deposit bed model of the CONACS code. [LMFBR]

A new Pool-Bed model of the CONACS (Containment Analysis Code System) code represents a major advance over the pool models of other containment analysis code (NABE code of France, CEDAN code of Japan and CACECO and CONTAIN codes of the United States). This new model advances pool-bed modeling because of the number of significant materials and processes which are included with appropriate rigor. This CONACS pool-bed model maintains material balances for eight chemical species (C, H/sub 2/O, Na, NaH, Na/sub 2/O, Na/sub 2/O/sub 2/, Na/sub 2/CO/sub 3/ and NaOH) that collect in the stationary liquid pool on the floor and in the desposit bed on the elevated shelf of the standard CONACS analysis cell.
Date: December 17, 1983
Creator: Peak, R.D.
System: The UNT Digital Library
Versatile laser glass inspection and damage testing facility (open access)

Versatile laser glass inspection and damage testing facility

A test facility is described which detects small opaque inclusions in large transparent components by using a commercial laser which delivers high energy pulses to the test sample at moderate frequency in a small diameter beam. The sample is automatically scanned such that each point in the volume is irradiated with ten pulses at twice the inclusion damage threshold - an amount sufficient to cause visible damage at inclusion sites. This approach permits detection of opaque inclusions in the parts per trillion and lower concentration range. The specifics of the device design and its performance are discussed in the context of automatic inclusion inspection and mapping in large laser optics.
Date: January 17, 1986
Creator: Marion, J. E.; Greiner, G. J.; Campbell, J. H.; Chaffee, P. H.; Hildum, J. S.; Grens, J. Z. et al.
System: The UNT Digital Library
Leak testing and repair of fusion devices (open access)

Leak testing and repair of fusion devices

The leak testing, reporting and vacuum leak repair techniques of the MFTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques will be developed for testing and repairing leaks on the 42 MFTF-B magnets. The leak-hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown), their associated piping, liquid nitrogen radiation shields, and piping. Additionally, during MFTF-B operation there will be warm water plasma shields and piping that require leak checking.
Date: June 17, 1983
Creator: Kozman, T. A.
System: The UNT Digital Library
Fragmentation of Suddenly Heated Liquids in ICF Reactors. Revision 1 (open access)

Fragmentation of Suddenly Heated Liquids in ICF Reactors. Revision 1

Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate because increased surface area will enhance the cooling and condensation of coolant ablated by the fusion x rays. Relaxation from the suddenly (neutron) heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The resulting expansion in a diverging geometry will hydrodynamically force the liquid to fragment, with vapor then forming from the new surfaces to fill the cavities. An energy minimization model is used to determine the fragment size that produces the least amount of non-fragment-center-of-mass energy; i.e., the sum of the surface and dilational kinetic energies. This model predicts fragmentation dependence on original system size and amount of isochoric heating as well as liquid density, Grueneisen parameter, surface tension, and sound speed. A two dimensional molecular dynamics code was developed to test the model at a microscopic scale for the Lennard-Jones fluid with its two adjustable constants chosen to represent lithium.
Date: April 17, 1985
Creator: Blink, J. A. & Hoover, W. G.
System: The UNT Digital Library
Advances in ICF power reactor design (open access)

Advances in ICF power reactor design

Fifteen ICF power reactor design studies published since 1980 are reviewed to illuminate the design trends they represent. There is a clear, continuing trend toward making ICF reactors inherently safer and environmentally benign. Since this trend accentuates inherent advantages of ICF reactors, we expect it to be further emphasized in the future. An emphasis on economic competitiveness appears to be a somewhat newer trend. Lower cost of electricity, smaller initial size (and capital cost), and more affordable development paths are three of the issues being addressed with new studies.
Date: April 17, 1985
Creator: Hogan, W.J. & Kulcinski, G.L.
System: The UNT Digital Library
Nonrelativistic theory of heavy-ion collisions (open access)

Nonrelativistic theory of heavy-ion collisions

A wide range of phenomena is observed in heavy-ion collisions, calling for a comprehensive theory based on fundamental principles of many-particle quantum mechanics. At low energies, the nuclear dynamics is controlled by the mean field, as we know from spectroscopic nuclear physics. We therefore expect the comprehensive theory of collisions to contain mean-field theory at low energies. The mean-field theory is the subject of the first lectures in this chapter. This theory can be studied quantum mechanically, in which form it is called TDHF (time-dependent Hartree-Fock), or classically, where the equation is called the Vlasov equation. 25 references, 14 figures.
Date: July 17, 1984
Creator: Bertsch, G.
System: The UNT Digital Library
Optimized flashlamp pumping of disc amplifiers (open access)

Optimized flashlamp pumping of disc amplifiers

Disk amplifier design for inertial fusion lasers has evolved with changing fusion-driver requirements from a primary emphasis on gain to a primary emphasis on efficiency. In this paper we compare Shiva and Nova amplifiers to a developmental amplifier (SSA) and show greater than a two-fold improvement in efficiency over past designs under all operating conditions. Experiments to optimize the efficiency of the SSA show that preionization of the flashlamps produces significant benefits and that the packing fraction of lamps is more important than the flashlamp reflector shape. They also show that the optimized flashlamp pulselength and reflector geometry depend on the desired stored energy in the laser medium. We have demonstrated a 7% storage efficiency at a stored fluence per disk of 0.5 J/cm/sup 2/ (stored energy density of 0.06 J/cm/sup 3/) and 4% at 2.0 J/cm/sup 2/ (0.25 J/cm/sup 3/). Comparison of SSA measurements with storage-efficiency calculations show that our flashlamp model accurately predicts the single-pass pumping of disk amplifiers. 24 refs., 22 figs.
Date: January 17, 1986
Creator: Murray, J. E.; Powell, H. T. & Woods, B. W.
System: The UNT Digital Library
Experiences with fast breeder reactor education in laboratory and short course settings (open access)

Experiences with fast breeder reactor education in laboratory and short course settings

The breeder reactor industry throughout the world has grown impressively over the last two decades. Despite the uncertainties in some national programs, breeder reactor technology is well established on a global scale. Given the magnitude of this technological undertaking, there has been surprisingly little emphasis on general breeder reactor education - either at the university or laboratory level. Many universities assume the topic too specialized for including appropriate courses in their curriculum - thus leaving students entering the breeder reactor industry to learn almost exclusively from on-the-job experience. The evaluation of four course presentations utilizing visual aids is presented.
Date: January 17, 1983
Creator: Waltar, A.E.
System: The UNT Digital Library