3 GeV Injector Design Handbook (open access)

3 GeV Injector Design Handbook

This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.
Date: December 16, 2009
Creator: Wiedemann, H.
Object Type: Report
System: The UNT Digital Library
100-NR-2 Apatite Treatability Test FY09 Status: High Concentration Calcium-Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization (open access)

100-NR-2 Apatite Treatability Test FY09 Status: High Concentration Calcium-Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization

100-NR-2 Apatite Treatability Test FY09 Status: High Concentration Calcium-Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization INTERIM LETTER REPORT
Date: December 16, 2009
Creator: Vermeul, Vincent R.; Fritz, Brad G.; Fruchter, Jonathan S.; Szecsody, James E. & Williams, Mark D.
Object Type: Report
System: The UNT Digital Library
Comparison of laser-based mitigation of fused silica surface damage using mid- versus far-infrared lasers (open access)

Comparison of laser-based mitigation of fused silica surface damage using mid- versus far-infrared lasers

Laser induced growth of optical damage can limit component lifetime and therefore operating costs of large-aperture fusion-class laser systems. While far-infrared (IR) lasers have been used previously to treat laser damage on fused silica optics and render it benign, little is known about the effectiveness of less-absorbing mid-IR lasers for this purpose. In this study, they quantitatively compare the effectiveness and efficiency of mid-IR (4.6 {micro}m) versus far-IR (10.6 {micro}m) lasers in mitigating damage growth on fused silica surfaces. The non-linear volumetric heating due to mid-IR laser absorption is analyzed by solving the heat equation numerically, taking into account the temperature-dependent absorption coefficient {alpha}(T) at {lambda} = 4.6 {micro}m, while far-IR laser heating is well-described by a linear analytic approximation to the laser-driven temperature rise. In both cases, the predicted results agree well with surface temperature measurements based on infrared radiometry, as well as sub-surface fictive temperature measurements based on confocal Raman microscopy. Damage mitigation efficiency is assessed using a figure of merit (FOM) relating the crack healing depth to laser power required, under minimally-ablative conditions. Based on their FOM, they show that for cracks up to at least 500 {micro}m in depth, mitigation with a 4.6 {micro}m mid-IR laser …
Date: December 16, 2009
Creator: Yang, S T; Matthews, M J; Elhadj, S; Cooke, D; Guss, G M; Draggoo, V G et al.
Object Type: Article
System: The UNT Digital Library
A Coordinated Approach to Communicating Pediatric-Related Information on Pandemic Influenza at the Community Level (open access)

A Coordinated Approach to Communicating Pediatric-Related Information on Pandemic Influenza at the Community Level

The purpose of this document is to provide a suggested approach, based on input from pediatric stakeholders, to communicating pediatric-related information on pandemic influenza at the community level in a step-by-step manner.
Date: December 16, 2009
Creator: CHE, HCTT
Object Type: Article
System: The UNT Digital Library
Disentangling Dark Matter Dynamics with Directional Detection (open access)

Disentangling Dark Matter Dynamics with Directional Detection

Inelastic dark matter reconciles the DAMA anomaly with other null direct detection experiments and points to a non-minimal structure in the dark matter sector. In addition to the dominant inelastic interaction, dark matter scattering may have a subdominant elastic component. If these elastic interactions are suppressed at low momentum transfer, they will have similar nuclear recoil spectra to inelastic scattering events. While upcoming direct detection experiments will see strong signals from such models, they may not be able to unambiguously determine the presence of the subdominant elastic scattering from the recoil spectra alone. We show that directional detection experiments can separate elastic and inelastic scattering events and discover the underlying dynamics of dark matter models.
Date: December 16, 2009
Creator: Lisanti, Mariangela & Wacker, Jay G.
Object Type: Article
System: The UNT Digital Library
EFFECTS OF TRITIUM GAS EXPOSURE ON ELECTRICALLY CONDUCTING POLYMERS (open access)

EFFECTS OF TRITIUM GAS EXPOSURE ON ELECTRICALLY CONDUCTING POLYMERS

Effects of beta (tritium) and gamma irradiation on the surface electrical conductivity of two types of conducting polymer films are documented to determine their potential use as a sensing and surveillance device for the tritium facility. It was shown that surface conductivity was significantly reduced by irradiation with both gamma and tritium gas. In order to compare the results from the two radiation sources, an approximate dose equivalence was calculated. The materials were also sensitive to small radiation doses (<10{sup 5} rad), showing that there is a measurable response to relatively small total doses of tritium gas. Spectroscopy was also used to confirm the mechanism by which this sensing device would operate in order to calibrate this sensor for potential use. It was determined that one material (polyaniline) was very sensitive to oxidation while the other material (PEDOT-PSS) was not. However, polyaniline provided the best response as a sensing material, and it is suggested that an oxygen-impermeable, radiation-transparent coating be applied to this material for future device prototype fabrication. A great deal of interest has developed in recent years in the area of conducting polymers due to the high levels of conductivity that can be achieved, some comparable to that …
Date: December 16, 2009
Creator: Kane, M.; Clark, E. & Lascola, R.
Object Type: Report
System: The UNT Digital Library
ENVIRONMENTAL MONITORING OF LEAKS USING TIME LAPSED LONG ELECTRODE ELECTRICAL RESISTIVITY (open access)

ENVIRONMENTAL MONITORING OF LEAKS USING TIME LAPSED LONG ELECTRODE ELECTRICAL RESISTIVITY

Highly industrialized areas pose challenges for surface electrical resistivity characterization due to metallic infrastructure. The infrastructure is typically more conductive than the desired targets and will mask the deeper subsurface information. These challenges may be minimized if steel-cased wells are used as long electrodes in the area near the target. We demonstrate a method of using long electrodes to electrically monitor a simulated leak from an underground storage tank with both synthetic examples and a field demonstration. The synthetic examples place a simple target of varying electrical properties beneath a very low resistivity layer. The layer is meant to replicate the effects of infrastructure. Both surface and long electrodes are tested on the synthetic domain. The leak demonstration for the field experiment is simulated by injecting a high conductivity fluid in a perforated well within the S tank farm at Hanford, and the resistivity measurements are made before and after the leak test. All data are processed in four dimensions, where a regularization procedure is applied in both the time and space domains. The synthetic test case shows that the long electrode ERM could detect relative changes in resistivity that are commensurate with the differing target properties. The surface electrodes, …
Date: December 16, 2009
Creator: Myers, D. A.; Rucker, D. F.; Fink, J. B. & Loke, M. H.
Object Type: Article
System: The UNT Digital Library
Feedback Configuration Tools for LHC Low Level RF (open access)

Feedback Configuration Tools for LHC Low Level RF

The LHC Low Level RF System (LLRF) is a complex multi-VME crate system which is used to regulate the superconductive cavity gap voltage as well as to lower the impedance as seen by the beam through low latency feedback. This system contains multiple loops with several parameters to be set before the loops can be closed. In this paper, we present a suite of MATLAB based tools developed to perform the preliminary alignment of the RF stations and the beginnings of a closed loop model based alignment routine. We briefly introduce the RF system and in particular the base band (time domain noise based) network analyzer system built into the LHC LLRF. The main focus of this paper is the methodology of the algorithms used by the routines within the context of the overall system. Measured results are presented that validate the technique. Because the RF systems are located in a cavern 120 m underground in a location which is relatively un-accessible without beam and completely un-accessible with beam present or magnets are energized, these remotely operated tools are a necessity for the CERN LLRF team to maintain and tune their LLRF systems in a similar fashion as to what …
Date: December 16, 2009
Creator: Van Winkle, D.; Fox, J.; Mastorides, T.; Rivetta, C.; Baudrenghien, P.; Butterworth, A. et al.
Object Type: Article
System: The UNT Digital Library
Hamiltonian Light-front Field Theory Within an AdS/QCD Basis (open access)

Hamiltonian Light-front Field Theory Within an AdS/QCD Basis

Non-perturbative Hamiltonian light-front quantum field theory presents opportunities and challenges that bridge particle physics and nuclear physics. Fundamental theories, such as Quantum Chromodynamics (QCD) and Quantum Electrodynamics (QED) offer the promise of great predictive power spanning phenomena on all scales from the microscopic to cosmic scales, but new tools that do not rely exclusively on perturbation theory are required to make connection from one scale to the next. We outline recent theoretical and computational progress to build these bridges and provide illustrative results for nuclear structure and quantum field theory. As our framework we choose light-front gauge and a basis function representation with two-dimensional harmonic oscillator basis for transverse modes that corresponds with eigensolutions of the soft-wall AdS/QCD model obtained from light-front holography.
Date: December 16, 2009
Creator: Vary, J.P.; Honkanen, H.; Li, Jun; Maris, P.; U., /Iowa State; Brodsky, S.J. et al.
Object Type: Article
System: The UNT Digital Library
In Situ Spectroscopic Observation of Activation and Transformation of Tantalum Suboxides (open access)

In Situ Spectroscopic Observation of Activation and Transformation of Tantalum Suboxides

Using ambient pressure X-ray Photoelectron Spectroscopy (AP-XPS), we were able to observe the process of oxidation of tantalum with different morphological parameters. Being able to trace surface evolution during oxidation, we evaluated activation energy of oxidation under the influence of strain and grain boundaries. It was found that the metal oxidized through three different stages and there was a transition stage where the phase transformation from suboxides to the equilibrium state of pentoxide. The applied stress and surface defects reduced the activation energy oxidation.
Date: December 16, 2009
Creator: Wang, Ke; Liu, Zhi; Cruz, Tirma Herranz; Salmeron, Miquel & Liang, Hong
Object Type: Article
System: The UNT Digital Library
Magnetism at spinel thin film interfaces probed through soft x-ray spectroscopy techniques (open access)

Magnetism at spinel thin film interfaces probed through soft x-ray spectroscopy techniques

Magnetic order and coupling at the interfaces of highly spin polarized Fe{sub 3}O{sub 4} heterostructures have been determined by surface sensitive and element specific soft x-ray spectroscopy and spectromicroscopy techniques. At ambient temperature, the interface between paramagnetic CoCr{sub 2}O{sub 4} or MnCr{sub 2}O{sub 4} and ferrimagnetic Fe{sub 3}O{sub 4} isostructural bilayers exhibits long range magnetic order of Co, Mn and Cr cations which cannot be explained in terms of the formation of interfacial MnFe{sub 2}O{sub 4} or CoFe{sub 2}O{sub 4}. Instead, the ferrimagnetism is induced by the adjacent Fe{sub 3}O{sub 4} layer and is the result of the stabilization of a spinel phase not achievable in bulk form. Magnetism at the interface region is observable up to 500 K, far beyond the chromite bulk Curie temperature of 50-95 K.
Date: December 16, 2009
Creator: Chopdekar, R.V.; Liberati, M.; Takamura, Y.; Kourkoutis, L. Fitting; Bettinger, J. S.; Nelson-Cheeseman, B. B. et al.
Object Type: Article
System: The UNT Digital Library
A Modern Interpretation of the Barney Diagram for Aluminum Solubility in Tank Waste (open access)

A Modern Interpretation of the Barney Diagram for Aluminum Solubility in Tank Waste

Experimental and modeling studies of aluminum solubility in Hanford tank waste have been developed and refined for many years in efforts to resolve new issues or develop waste treatment flowsheets. The earliest of these studies was conducted by G. Scott Barney, who performed solubility studies in highly concentrated electrolyte solutions to support evaporator campaign flowsheets in the 1970's. The 'Barney Diagram', a term still widely used at Hanford today, suggested gibbsite ({gamma}-Al(OH){sub 3}) was much more soluble in tank waste than in simple sodium hydroxide solutions. These results, which were highly surprising at the time, continue to be applied to new situations where aluminum solubility in tank waste is of interest. Here, we review the history and provide a modern explanation for the large gibbsite solubility observed by Barney, an explanation based on basic research that has been performed and published in the last 30 years. This explanation has both thermodynamic and kinetic aspects. Thermodynamically, saturated salt solutions stabilize soluble aluminate species that are minor components in simple sodium hydroxide solutions. These species are the aluminate dimer and the sodium-aluminate ion-pair. Ion-pairs must be present in the Barney simulants because calculations showed that there was insufficient space between the highly …
Date: December 16, 2009
Creator: Reynolds, J. G. & Reynolds, D. A.
Object Type: Article
System: The UNT Digital Library
A Multi-Wavelength Investigation of the Unidentified Gamma-Ray Source HESS J1708-410 (open access)

A Multi-Wavelength Investigation of the Unidentified Gamma-Ray Source HESS J1708-410

We report on recent XMM-Newton observations, archival radio continuum and CO data, and SED modeling of the unidentified Galactic plane source HESS J1708-410. No significant extended X-ray emission is observed, and we place an upper limit of 3.2 x 10{sup -13} erg cm{sup -2} s{sup -1} in the 2-4 keV range for the region of TeV emission. Molonglo Galactic Plane Survey data is used to place an upper limit of 0.27 Jy at 843 MHz for the source, with a 2.4 GHz limit of 0.4 Jy from the Parkes survey of the southern Galactic plane. {sup 12}CO (J 1 {yields} 0) data of this region indicates a plausible distance of 3 kpc for HESS J1708-410. SED modeling of both the H.E.S.S. detection and flux upper limits offer useful constraints on the emission mechanisms, magnetic field, injection spectrum, and ambient medium surrounding this source.
Date: December 16, 2009
Creator: Van Etten, Adam; Funk, Stefan; U., /Stanford; Hinton, Jim & U., /Leeds
Object Type: Article
System: The UNT Digital Library
Radiation Risk from Chronic Low Dose-Rate Radiation Exposures: The Role of Life-Time Animal Studies - Workshop October 2005 (open access)

Radiation Risk from Chronic Low Dose-Rate Radiation Exposures: The Role of Life-Time Animal Studies - Workshop October 2005

As a part of Radiation research conference, a workshop was held on life-long exposure studies conducted in the course of irradiation experiements done at Argonne National Laboratory between 1952-1992. A recent review article documents many of the issues discussed at that workshop.
Date: December 16, 2009
Creator: Woloschak, Gayle
Object Type: Report
System: The UNT Digital Library
Simulations of the Microwave Sky (open access)

Simulations of the Microwave Sky

We create realistic, full-sky, half-arcminute resolution simulations of the microwave sky matched to the most recent astrophysical observations. The primary purpose of these simulations is to test the data reduction pipeline for the Atacama Cosmology Telescope (ACT) experiment; however, we have widened the frequency coverage beyond the ACT bands and utilized the easily accessible HEALPix map format to make these simulations applicable to other current and near future microwave background experiments. Some of the novel features of these simulations are that the radio and infrared galaxy populations are correlated with the galaxy cluster and group populations, the primordial microwave background is lensed by the dark matter structure in the simulation via a ray-tracing code, the contribution to the thermal and kinetic Sunyaev-Zel'dovich (SZ) signals from galaxy clusters, groups, and the intergalactic medium has been included, and the gas prescription to model the SZ signals has been refined to match the most recent X-ray observations. The cosmology adopted in these simulations is also consistent with the WMAP 5-year parameter measurements. From these simulations we find a slope for the Y{sub 200} - M{sub 200} relation that is only slightly steeper than self-similar, with an intrinsic scatter in the relation of {approx} …
Date: December 16, 2009
Creator: Sehgal, Neelima; /KIPAC, Menlo Park; Bode, Paul; /Princeton U., Astrophys. Sci. Dept.; Das, Sudeep; /Princeton U., Astrophys. Sci. Dept. /Princeton U. et al.
Object Type: Article
System: The UNT Digital Library
Strange Bedfellows: Quantum Mechanics and Data Mining (open access)

Strange Bedfellows: Quantum Mechanics and Data Mining

Last year, in 2008, I gave a talk titled Quantum Calisthenics. This year I am going to tell you about how the work I described then has spun off into a most unlikely direction. What I am going to talk about is how one maps the problem of finding clusters in a given data set into a problem in quantum mechanics. I will then use the tricks I described to let quantum evolution lets the clusters come together on their own.
Date: December 16, 2009
Creator: Weinstein, Marvin
Object Type: Article
System: The UNT Digital Library
Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium (open access)

Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium

Exposure to ionizing radiation produces few immediate outwardly-visible clinical signs, yet, depending on dose, can severely damage vital physiological functions within days to weeks and produce long-lasting health consequences among survivors. In the event of a radiological accident, the rapid evaluation of the individual absorbed dose is paramount to discriminate the worried but unharmed from those individuals who must receive medical attention. Physical, clinical and biological dosimetry are usually combined for the best dose assessment. However, because of the practical limits of physical and clinical dosimetry, many attempts have been made to develop a dosimetry system based on changes in biological parameters, including techniques for hematology, biochemistry, immunology, cytogenetics, etc. Lymphocyte counts and chromosome aberrations analyses are among the methods that have been routinely used for estimating radiation dose. However, these assays require several days to a week to be completed and therefore cannot be used to obtain a fast estimate of the dose during the first few days after exposure when the information would be most critical for identifying victims of radiation accidents who could benefit the most by medical intervention. The steadily increasing sophistication in our understanding of the early biochemical responses of irradiated cells and tissues provides …
Date: November 16, 2009
Creator: Coleman, Matthew A. (info: Ph.D.); Ramakrishnan, Narayani (info:Ph.D); Amundson, Sally A.; Tucker, James D. (info: Ph.D.); Dertinger, Stephen D. (info:Ph.D); Ossetrova, Natalia I. (info:Ph.D) et al.
Object Type: Article
System: The UNT Digital Library
DIONEX ICS3000 ION CHROMATOGRAPHY SYSTEM INSTALLATION AND INSTRUMENT ASSESSMENT FOR SRNL APPLICATIONS (open access)

DIONEX ICS3000 ION CHROMATOGRAPHY SYSTEM INSTALLATION AND INSTRUMENT ASSESSMENT FOR SRNL APPLICATIONS

Ion Chromatography (IC) is routinely used at the Savannah River National Laboratory (SRNL) for sample analysis and characterization. Results from IC analysis are valued in corrosion control maintenance and measurement programs, remediation waste process control, soil and ground water measurement, nuclear materials processing, and various other research and development programs. Presented in this report are analytical methods developed on a DIONEX ICS3000 Reagent Free Ion Chromatography (RFIC) system located in AD at SRNL. This IC system contains two independent analysis channels comprising of a mobile phase generator, a pump, stationary phase columns, a suppressor and a conductivity detector. One channel is dedicated to anion analysis using Potassium Hydroxide (KOH) as the mobile phase while a second channel is configured for cation analysis using Methanesulfonic Acid (MSA) as the mobile phase. Both channels share an autosampler and the peak analysis software, Chromeleon{reg_sign} v.6.8. Instrument configuration is modified from the manufacturer for radiological service. Listed within this report are Dionex ICS3000 parameters and results for the analysis of routine anions and cations. Additional method parameters and discussion are presented on the analysis of Acetate (CH{sub 3}COO{sup -}) and Iodate (IO{sub 3}{sup -}). Previous IC analysis instruments at AD have been based upon …
Date: November 16, 2009
Creator: Wiedenman, B. & White, T.
Object Type: Report
System: The UNT Digital Library

Fuel Cell Power Model for CHHP System Economics and Performance Analysis

Presentation about Fuel Cell Power (FCPower) Model used to analyze the economics and performance of combined heat, hydrogen, and power (CHHP) systems.
Date: November 16, 2009
Creator: Steward, D.
Object Type: Presentation
System: The UNT Digital Library
Integrated Kinetic Simulation of Laser-Plasma Interactions, Fast-Electron Generation and Transport in Fast Ignition (open access)

Integrated Kinetic Simulation of Laser-Plasma Interactions, Fast-Electron Generation and Transport in Fast Ignition

We present new results on the physics of short-pulse laser-matter interaction of kilojoule-picosecond pulses at full spatial and temporal scale, using a new approach that combines a 3D collisional electromagnetic Particle-in-Cell code with an MHD-hybrid model of high-density plasma. In the latter, collisions damp out plasma waves, and an Ohm's law with electron inertia effects neglected determines the electric field. In addition to yielding orders of magnitude in speed-up while avoiding numerical instabilities, this allows us to model the whole problem in a single unified framework: the laser-plasma interaction at sub-critical densities, energy deposition at relativistic critical densities, and fast-electron transport in solid densities. Key questions such as the multi-picosecond temporal evolution of the laser energy conversion into hot electrons, the impact of return currents on the laser-plasma interaction, and the effect of self-generated electric and magnetic fields on electron transport will be addressed. We will report applications to current experiments.
Date: November 16, 2009
Creator: Kemp, A; Cohen, B & Divol, L
Object Type: Article
System: The UNT Digital Library
Lac du Flambeau Band of Lake Superior Chippewa Indians Strategic Energy Plan (open access)

Lac du Flambeau Band of Lake Superior Chippewa Indians Strategic Energy Plan

This plan discusses the current energy use on the Lac du Flambeau Reservation, the current status of the Tribe's energy program, as well as the issues and concerns with energy on the reservation. This plan also identifies and outlines energy opportunities, goals, and objectives for the Tribe to accomplish. The overall goal of this plan is to address the energy situation of the reservation in a holistic manner for the maximum benefit to the Tribe. This plan is an evolving document that will be re-evaluated as the Tribe's energy situation changes.
Date: November 16, 2009
Creator: Hoover, Bryan
Object Type: Report
System: The UNT Digital Library
Modeling acid-gas generation from boiling chloride brines (open access)

Modeling acid-gas generation from boiling chloride brines

This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental …
Date: November 16, 2009
Creator: Zhang, Guoxiang; Spycher, Nicolas; Sonnenthal, Eric & Steefel, Carl
Object Type: Article
System: The UNT Digital Library
Muon-induced backgrounds in the CUORICINO experiment (open access)

Muon-induced backgrounds in the CUORICINO experiment

To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.
Date: November 16, 2009
Creator: Andreotti, E.; Arnaboldi, C.; Avignone, F. T.; Balata, M.; Bandac, I.; Barucci, M. et al.
Object Type: Article
System: The UNT Digital Library
National Ignition Campaign Hohlraum Energetics (open access)

National Ignition Campaign Hohlraum Energetics

The first series of experiments on the National Ignition Facility (NIF) [E. I. Moses, R. N. Boyd, B. A. Remington, C. J. Keane, and R. Al-Ayat, 'The National Ignition Facility: ushering in a new age for high energy density science,' Phys. Plasmas 16, 041006 (2009)] tested ignition hohlraum 'energetics,' a term described by four broad goals: (1) Measurement of laser absorption by the hohlraum; (2) Measurement of the x-ray radiation flux (T{sub RAD}{sup 4}) on the surrogate ignition capsule; (3) Quantitative understanding of the laser absorption and resultant x-ray flux; and (4) Determining whether initial hohlraum performance is consistent with requirements for ignition. This paper summarizes the status of NIF hohlraum energetics experiments. The hohlraum targets and experimental design are described, as well as the results of the initial experiments. The data demonstrate low backscattered energy (< 10%) for hohlraums filled with helium gas. A discussion of our current understanding of NIF hohlraum x-ray drive follows, including an overview of the computational tools, i.e., radiation-hydrodynamics codes, that have been used to design the hohlraums. The performance of the codes is compared to x-ray drive and capsule implosion data from the first NIF experiments. These results bode well for future NIF …
Date: November 16, 2009
Creator: Meezan, N B; Atherton, L J; Callahan, D A; Dewald, E L; Dixit, S N; Dzenitis, E G et al.
Object Type: Article
System: The UNT Digital Library