Fabrication of Efficient, Large Aperture Transmission Diffraction Gratings by Ion-Beam Etching (open access)

Fabrication of Efficient, Large Aperture Transmission Diffraction Gratings by Ion-Beam Etching

The utilization of high-power short pulse laser employing chirped-pulse amplification (CPA) for material processing and inertial confinement research is widely increasing. The performance of these high-power CPA laser system continues to be limited by the ability of the pulse compression gratings to hold up to the high-average-power or high-peak-power of the laser. Pulse compression gratings used in transmission and fabricated out of bulk fused silica have intrinsically the highest laser damage threshold when compared with metal or multilayer dielectric gratings that work in reflection. LLNL has developed processing capability to produce high efficiency fused silica transmission gratings at sizes useful to future Petawatt-class systems, and has demonstrated high efficiency at smaller aperture. This report shows that fused silica diffraction exhibiting >95% efficiency into the -1 diffraction order in transmission (90{sup o} deflection of the incident light, at an incidence angle of 45{sup o} to the grating face). The microstructure of this grating consisted of grooves ion-beam etched to a depth of 1.6 microns with a pitch of 0.75 microns, using a holographically produced photoresist mask that was subsequently stripped away in significance to the fabrication of the small scale high efficiency grating was the development of the processing technology and …
Date: September 14, 2000
Creator: Nguyen, H T; Bryan, S R; Britten, J A & Perry, M D
Object Type: Report
System: The UNT Digital Library
Evaluation of SAFT/T-SAFT Technology for the Inspection of Hanford's Double Shell Waste Tank Knuckle Regions (open access)

Evaluation of SAFT/T-SAFT Technology for the Inspection of Hanford's Double Shell Waste Tank Knuckle Regions

Results of the examinations conducted at Pacific Northwest National Laboratory provided a firm engineering basis for establishing the proof-of-principle effectiveness for utilizing a combination of pulse-echo Synthetic Aperture Focusing Technique (SAFT) and tandem-SAFT (T-SAFT) inspection methodologies as applied to the problem of flaw detection, localization, and sizing in Hanford's double shell waste tank knuckle region and beyond.
Date: September 14, 2000
Creator: Pardini, Allan F. & Diaz, Aaron A.
Object Type: Report
System: The UNT Digital Library
Anarchy and hierarchy (open access)

Anarchy and hierarchy

We advocate a new approach to study models of fermion massesand mixings, namely anarchy proposed in hep-ph/9911341. In this approach,we scan the O(1) coefficients randomly. We argue that this is the correctapproach when the fundamental theory is sufficiently complicated.Assuming there is no physical distinction among three generations ofneutrinos, the probability distributions in MNS mixing angles can bepredicted independent of the choice of the measure. This is because themixing angles are distributed according to the Haar measure of the Liegroups whose elements diagonalize the mass matrices. The near-maximalmixings, as observed in the atmospheric neutrino data and as required inthe LMA solution to the solar neutrino problem, are highly probable. Asmall hierarchy between the Delta m2 for the atmospheric and the solarneutrinos is obtained very easily; the complex seesaw case gives ahierarchy of a factor of 20 as the most probable one, even though thisconclusion is more measure-dependent. U_e3 has to be just below thecurrent limit from the CHOOZ experiment. The CP-violating parameter sindelta is preferred to be maximal. We present a simple SU(5)-likeextension of anarchy to the charged-lepton and quark sectors which workswell phenomenologically.
Date: September 14, 2000
Creator: Haba, Naoyuki & Murayama, Hitoshi
Object Type: Article
System: The UNT Digital Library
EQ6 Calculation for Chemical Degradation of Shippingport LWBR (TH/U Oxide) Spent Nuclear Fuel Waste Packages (open access)

EQ6 Calculation for Chemical Degradation of Shippingport LWBR (TH/U Oxide) Spent Nuclear Fuel Waste Packages

The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management & Operating contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Shippingport Light Water Breeder Reactor (LWBR) (Ref. 1). The Shippingport LWBR SNF has been considered for disposal at the potential Yucca Mountain site. Because of the high content of fissile material in the SNF, the waste package (WP) design requires special consideration of the amount and placement of neutron absorbers and the possible loss of absorbers and SNF materials over geologic time. For some WPs, the outer shell corrosion-resistant material (CRM) and the corrosion-allowance inner shell may breach (Refs. 2 and 3), allowing the influx of water. Water in the WP will moderate neutrons, increasing the likelihood of a criticality event within the WP; and the water may, in time, gradually leach the fissile components and neutron absorbers from the WP, further affecting the neutronics of the system. This study presents calculations of the long-term geochemical behavior of WPs containing a Shippingport LWBR SNF seed assembly, and high-level waste (HLW) glass canisters arranged according to the codisposal concept (Ref. 4). The specific study objectives were …
Date: September 14, 2000
Creator: Arthur, S.
Object Type: Report
System: The UNT Digital Library
Neutron detection technique (open access)

Neutron detection technique

The Sudbury Neutrino Observatory (SNO) has the ability to measure the total flux of all active flavors of neutrinos using the neutral current reaction, whose signature is a neutron. By comparing the rates of the neutral current reaction to the charged current reaction, which only detects electron neutrinos, one can test the neutrino oscillation hypothesis independent of solar models. It is necessary to understand the neutron detection efficiency of the detector to make use of the neutral current reaction. This report demonstrates a coincidence technique to identify neutrons emitted from the {sup 252}Cf neutron calibration source. The source releases on average four neutrons when a {sup 252}Cf nucleus spontaneously fissions. Each neutron is detected as a separate event when the neutron is captured by a deuteron, releasing a gamma ray of approximately 6.25 MeV. This gamma ray is in turn detected by the photomultiplier tube (PMT) array. By investigating the time and spatial separation between neutron-like events, it is possible to obtain a pure sample of neutrons for calibration study. Preliminary results of the technique applied to two calibration runs are presented.
Date: September 14, 2000
Creator: Oblath, N.S. & Poon, A.W.P.
Object Type: Report
System: The UNT Digital Library
Tank Characterization Report for Double Shell Tank 241AZ102 (open access)

Tank Characterization Report for Double Shell Tank 241AZ102

None
Date: September 14, 2000
Creator: Adams, M. R.
Object Type: Report
System: The UNT Digital Library
The Effects of Moisture on LiD Single Crystals Studied by Temperature Programmed Reaction (open access)

The Effects of Moisture on LiD Single Crystals Studied by Temperature Programmed Reaction

Temperature programmed reaction (TPR) technique was performed on LiOH powders and LiD single crystals previously exposed to different moisture levels. Our results show that the LiOH decomposition process has an activation energy barrier of 30 to 33.1 kcal/mol. The LiOH structure is stable even if kept at 320 K for 100 years. However, LiOH structures formed on the surface of LiD during moisture exposure at low dosages may have multiple activation energy barriers, some of which may be much lower than 30 kcal/mol. We attribute the lowering of the activation energy barrier for the LiOH decomposition to the existence of dangling bonds, cracks, and other long range disorders in the LiOH structures formed at low levels of moisture exposure. These defective LiOH structures may decompose significantly over the next 100 years of storage even at room temperature. At high moisture exposure levels, LiOH.H{sub 2}O formation is observed. The release of H{sub 2}O molecules from LiOH.H{sub 2}O structure has small activation energy barriers in the range of 13.8 kcal/mol to 16.0 kcal/mol. The loosely bonded H{sub 2}O molecules in the LiOH.H{sub 2}O structure can be easily pumped away at room temperature in a reasonable amount of time. Our experiments also suggest …
Date: September 14, 2000
Creator: Dinh, L.; Balooch, M.; Cecala, C. M. & Leckey, J. H.
Object Type: Article
System: The UNT Digital Library
Immobilized High Level Waste (HLW) Interim Storage Alternative Generation and analysis and Decision Report 2nd Generation Implementing Architecture (open access)

Immobilized High Level Waste (HLW) Interim Storage Alternative Generation and analysis and Decision Report 2nd Generation Implementing Architecture

Two alternative approaches were previously identified to provide second-generation interim storage of Immobilized High-Level Waste (IHLW). One approach was retrofit modification of the Fuel and Materials Examination Facility (FMEF) to accommodate IHLW. The results of the evaluation of the FMEF as the second-generation IHLW interim storage facility and subsequent decision process are provided in this document.
Date: September 14, 2000
Creator: CALMUS, R.B.
Object Type: Report
System: The UNT Digital Library
Novel Miniature Spectrometer For Remote Chemical Detection (open access)

Novel Miniature Spectrometer For Remote Chemical Detection

New chemical sensing technologies are critically important for addressing many of EM's priority needs as discussed in detail at http://emsp.em.doe.gov/needs. Many technology needs were addressed by this research. For example, improved detection strategies are needed for non-aqueous phase liquids (NAPL's), such as PCE (Cl2C=CCl2) and TCE (HClC=CCl2), which persist in the environment due their highly stable structures. By developing a miniature, ultra-sensitive, selective, and field-deployable detector for NAPL's, the approximate source location could be determined with minimal investigative expense. Contaminant plumes could also be characterized in detail. The miniature spectrometer developed under Project No.60231 could also permit accurate rate measurements in less time, either in the field or the laboratory, which are critically important in the development, testing, and ultimate utilization of models for describing contaminant transport. The technology could also be used for long-term groundwater monitoring or long-term stewardship in general. Many science needs are also addressed by the Project 60231, since the effort significantly advances the measurement science of chemical detection. Developed under Project No.60231, evanescent wave cavity ring-down spectroscopy (EW-CRDS) is a novel form of CRDS, which is an the emerging optical absorption technique. Several review articles on CRDS, which has been generally applied only to gas-phase …
Date: September 14, 2000
Creator: Pipino, Andrew C.R.
Object Type: Report
System: The UNT Digital Library
Study of the effects of D{sub 2}O circulation (open access)

Study of the effects of D{sub 2}O circulation

The Sudbury Neutrino Observatory (SNO) has been collecting data since November 1999. The study of whether or not the D{sub 2}O circulation affects the data is an important part of understanding how the SNO detector behaves. This report looks at several characteristics of the data to determine to what extent the D{sub 2}O circulation affects the data. We found that there is no evidence for any dependence of event rates in the cleaned data sets on the state of D{sub 2}O circulation.
Date: September 14, 2000
Creator: Oblath, N.S. & Poon, A.W.P.
Object Type: Report
System: The UNT Digital Library
Technical Information to Support Double Shell Tank (DST) Emergency Annulus Pumping [SEC 1 and 2] (open access)

Technical Information to Support Double Shell Tank (DST) Emergency Annulus Pumping [SEC 1 and 2]

This document provides the design calculations for the DST Annulus Emergency Pumping Project. This document also contains essential information relative to DST annulus emergency pumping that may not be found in other documents. This information consists of the following: Index drawing for annulus pumping; References to the Acceptance Test Report, DST Emergency Pumping Guide, Time Deployment study, etc.; Statements of work; and Reference CEIS and RMIS numbers. A Vendor Information document, VI-50121, is not included in this document, but a copy can be obtained by contacting Document Control Services. This document contains various information regarding the Hydrostar pumps, such as the air motor, cylinder size, pump installation and operation manual. It also contains information regarding the Flygt BS2060 submersible pump, such as parts list, pump handling, preventative maintenance, overhaul and repair. In addition, this document also has information on 3-way PM ball valves, electrical skid components and the alternate Gurman-Rupp stainless steel submersible pump.
Date: September 14, 2000
Creator: REBERGER, D.W.
Object Type: Report
System: The UNT Digital Library
Reaction of LiD with moisture by temperature programmed reaction (TPR) (open access)

Reaction of LiD with moisture by temperature programmed reaction (TPR)

The temperature programmed reaction technique was performed on LiOH powders and LiD single crystals previously exposed to different moisture levels. Our results show that the LiOH decomposition process has an activation energy barrier of 30 to 33.1 kcal/mol. The LiOH structure is stable at 320 K for 100 years. However, LiOH structures formed on the surface of LiD during moisture exposure at low dosages may have multiple activation energy barriers, some of which may be much lower than 30 kcal/mol. We attribute the lowering of the activation energy barrier for the LiOH decomposition to the existence of dangling bonds, cracks, and other long range disorders in the LiOH structures formed at low levels of moisture exposure. These defective LiOH structures may decompose significantly over the next 100 years of storage even at room temperature. At high moisture exposure levels, LiOH.H{sub 2}O formation is observed. The release of H{sub 2}O molecules from LiOH.H{sub 2}O structure has small activation energy barriers in the range of 13.8 kcal/mol to 16.0 kcal/mol. The loosely bonded H{sub 2}O molecules in the LiOH.H{sub 2}O structure can be easily pumped away at room temperature in a reasonable amount of time. Our experiments also suggest that handling LiD …
Date: September 14, 2000
Creator: Dinh, L N; Balooch, M; Cecala, C M & Leckey, J H
Object Type: Article
System: The UNT Digital Library
Reaction of LiD with water vapor: thermogravimetric and scanning electron microscopy studies (open access)

Reaction of LiD with water vapor: thermogravimetric and scanning electron microscopy studies

The kinetics of hydroxide film growth on LiD have been studied by the thermogravimetric method in nitrogen saturated with water vapor and by scanning electron microscopy (SEM) of samples that have been exposed to air with 50% relative humidity. The reaction probability is estimated to be 4 x 10{sup -7} for LiD exposed to ambient air with 50% relative humidity, suggesting that the diffusion through the hydroxide film is not the limiting step on the overall process at high moisture levels. The rate of growth is drastically reduced when the temperature is increased to 60 C.
Date: September 14, 2000
Creator: Balooch, M; Dinh, L N & LeMay, J D
Object Type: Article
System: The UNT Digital Library
Concoa SCHe Pressure Regulators and Reotemp Pressure Gauge (SCHe Tank Outlet) (open access)

Concoa SCHe Pressure Regulators and Reotemp Pressure Gauge (SCHe Tank Outlet)

None
Date: September 14, 2000
Creator: Miska, C. R.
Object Type: Report
System: The UNT Digital Library
Liquid Hydrofluoric Acid Sorption Using Solid Media - Part 1 (open access)

Liquid Hydrofluoric Acid Sorption Using Solid Media - Part 1

The conversion of the uranium hexafluoride (UF{sub 6}) which is removed from the Molten Salt Reactor Experiment (MSRE), into a stable oxide for long-term storage will produce a significant amount of slightly contaminated, concentrated aqueous hydrofluoric acid (HF). Sin&the handling of this HF is complicated and dangerous, it was decided to transform it into a stable solid fluoride (e.g., CaF{sub 2}, AlF{sub 3}, and MgF{sub 2}). Tests have been performed to identify the best media to use for trapping the HF. These tests are described in this report. The first series of tests evaluated 37 trapping materials using a 6 wt % solution of HF. The solution was pumped through a 3.8-cm-diam column at a slow rate, and samples were taken in 100-mL batches until it was determined that the media could no longer neutralize the solution. Each bed volume of media was evaluated for its retention of fluoride and for its plugging problems. Mixtures of calcium hydroxide and blast furnace slag (BFS) with high Surface areas (18-30 mesh) performed the best. A mixture of 80 wt % calcium hydroxide and 20 wt % BFS was capable of loading 0.134 g HF per cubic centimeter (cm{sup 3}) of media. Other …
Date: September 14, 2000
Creator: Osborne, P. E.
Object Type: Report
System: The UNT Digital Library
Strengthening of Trench Cover Plates for Switchgear Building (open access)

Strengthening of Trench Cover Plates for Switchgear Building

The objective of this calculation is to strengthen the existing trench cover plates of the Electrical Switchgear Building (BLDG 5010) of the Exploratory Studies Facility. A remodeling effort will change the portion of the facility that has the trenches for electrical cables to a craft/shop area. The users of the building will be using a forklift in this area (Clark CGP 30 forklift with a capacity of 3 tons). The trench covers require strengthening to support the wheel loads from the forklift. The output of this calculation will be sketches revising the floor plate details of DWG YMP-025-1-7007-ST103, Rev 02. (Details 4 and 5).
Date: September 14, 2000
Creator: Ruben, Michael S.
Object Type: Report
System: The UNT Digital Library
Modular approach to achieving the next-generation x-ray light source. (open access)

Modular approach to achieving the next-generation x-ray light source.

None
Date: September 14, 2000
Creator: Biedron, S. G.; Milton, S. V. & Freund, Henry P.
Object Type: Article
System: The UNT Digital Library
Partitioning Tracers for In-Situ Measurement of Nonaqueous Phase Liquids in the Subsurface - Final Report - 09/15/1996 - 09/14/2000 (open access)

Partitioning Tracers for In-Situ Measurement of Nonaqueous Phase Liquids in the Subsurface - Final Report - 09/15/1996 - 09/14/2000

The overall goal of the proposed project is to explore the use of partitioning tracers to characterize dense nonaqueous phase liquids (DNAPLs) in aquifer systems. Bulk-phase partitioning tracers will be investigated to detect and determine DNAPL saturation, while interface partitioning tracers will be investigated to measure the area of the DNAPL-water interface. The specific objectives that will be addressed to accomplish this goal are: (1) Investigate the use of partitioning tracers to detect and determine both the saturation and interfacial area of DNAPLs in saturated porous media. (2) Investigate the effect of rate-limited mass transfer on the transport behavior of partitioning tracers. (3) Investigate the effect of porous-media heterogeneity on the transport behavior of partitioning tracers. (4) Develop and evaluate mathematical models capable of simulating the transport of partitioning tracers in complex systems. This proposal outlines an integrated approach for the development and testing of a unique method for detecting and measuring DNAPL in aquifer systems. The approach combines one-dimensional laboratory experiments, three-dimensional intermediate-scale flow cell experiments, physical methods for DNAPL description (including dual-energy gamma radiation), and advanced modeling techniques. This approach will allow a new, promising technique for characterizing DNAPL in aquifer systems to be verified by established laboratory …
Date: September 14, 2000
Creator: Brusseau, Mark L.
Object Type: Report
System: The UNT Digital Library
Particle production for a muon storage ring: I. Targetry and pi/mu yield (open access)

Particle production for a muon storage ring: I. Targetry and pi/mu yield

Efficient production and collection of a large number of muons is needed to make a neutrino factory based on a muon storage ring viable. Results of extensive MARS simulations are reported for 2 to 30 GeV protons on various targets in a 20 T hybrid solenoid, followed by a matching section and decay channel. Part 1 describes pion and muon yields, targetry issues, and beam energy and power considerations. Part 2 describes radiation loads on targets, the capturing system and shielding.
Date: September 14, 2000
Creator: Mokhov, Nikolai V.
Object Type: Article
System: The UNT Digital Library
The anomaly and reggeon field theory in QCD (open access)

The anomaly and reggeon field theory in QCD

The appearance of the U(1) anomaly in the interactions of reggeized gluons is described. Also discussed is the crucial role the anomaly can play in providing the non-perturbative properties necessary for a transition from gluon and quark reggeon diagrams to hadron reggeons and a reggeon field theory description of the pomeron.
Date: September 14, 2000
Creator: White, A. R.
Object Type: Article
System: The UNT Digital Library
An energy recovery electron linac-on-ring collider (open access)

An energy recovery electron linac-on-ring collider

We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10{sup 33}(per nucleon) level have been proposed recently as a means for studying hadronic structure. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations (2) reduction of the synchrotron radiation load in the detectors (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored …
Date: September 14, 2000
Creator: Merminga, L.; Krafft, G. A.; Lebedev, V. A. & Ben-Zvi, Ilan
Object Type: Article
System: The UNT Digital Library
Index of Refraction and VISAR Windows (open access)

Index of Refraction and VISAR Windows

None
Date: September 14, 2000
Creator: HAYES,DENNIS BREWSTER
Object Type: Article
System: The UNT Digital Library
Effects of Alternating Bias Irradiation on Defects in MOS Devices (open access)

Effects of Alternating Bias Irradiation on Defects in MOS Devices

None
Date: September 14, 2000
Creator: FELIX,J.A.; FLEETWOOD,D.M.; RIEWE,LEONARD CHARLES & WINOKUR,PETER S.
Object Type: Article
System: The UNT Digital Library
Optimized Wakefield computations using a network model (open access)

Optimized Wakefield computations using a network model

During the course of the last decade, traveling wave accelerating structures for a future Linear Collider have been the object of intense R and D efforts. An important problem is the efficient computation of the long range wakefield with the ability to include small alignment and tuning errors. To that end, SLAC has developed an RF circuit model with a demonstrated ability to reproduce experimentally measured wakefields. The wakefield computation involves the repeated solution of a deterministic system of equations over a range of frequencies. By taking maximum advantage of the sparsity of the equations, they have achieved significant performance improvements. These improvements make it practical to consider simulations involving an entire linac ({approximately} 10{sup 3} structures). One might also contemplate assessing, in real time, the impact of fabrication errors on the wakefield as an integral part of quality control.
Date: September 14, 2000
Creator: Ng, J.-F. Ostiguy and K.-Y.
Object Type: Article
System: The UNT Digital Library