New Low Emittance Lattice for the Super-B Accelerator (open access)

New Low Emittance Lattice for the Super-B Accelerator

New low emittance lattices have been designed for the asymmetric SuperB accelerator, aiming at a luminosity of 10{sup 36} cm{sup -2} s{sup -1}. Main optics features are two alternating arc cells with different horizontal phase advance, decreasing beam emittance and allowing at the same time for easy chromaticity correction in the arcs. Emittance can be further reduced by a factor of two for luminosity upgrade. Spin rotation schemes for the e{sup -} beam have been studied to provide longitudinal polarization at the IP, and implementation into the lattice is in progress.
Date: October 21, 2011
Creator: Biagini, M.E.; Boscolo, M.; Raimondi, P.; Tomassini, S.; Zobov, M.; /Frascati et al.
Object Type: Article
System: The UNT Digital Library
An experimental apparatus for diffraction-limites soft x-ray nanofocusing (open access)

An experimental apparatus for diffraction-limites soft x-ray nanofocusing

Realizing the experimental potential of high-brightness, next generation synchrotron and free-electron laser light sources requires the development of reflecting x-ray optics capable of wavefront preservation and high-resolution nano-focusing. At the Advanced Light Source (ALS) beamline 5.3.1, we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for diffraction-limited Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of wavefront-sensing tests with increasing accuracy and sensitivity, including scanning-slit Hartmann tests, grating-based lateral shearing interferometry, and quantitative knife-edge testing. We describe the original experimental techniques and alignment methodology that have enabled us to optimally set a bendable KB mirror to achieve a focused, FWHM spot size of 150 nm, with 1 nm (1.24 keV) photons at 3.7 mrad numerical aperture. The predictions of wavefront measurement are confirmed by the knife-edge testing.The side-profiled elliptically bent mirror used in these one-dimensional focusing experiments was originally designed for a much different glancing angle and conjugate distances. This work demonstrates that high-accuracy, at-wavelength wavefront-slope feedback can be used to optimize the pitch, roll, and mirror-bending forces in situ, using procedures that are deterministic and repeatable.
Date: October 21, 2011
Creator: Merthe, Daniel; Goldberg, Kenneth; Yashchuk, Valeriy; Yuan, Sheng; McKinney, Wayne; Celestre, Richard et al.
Object Type: Article
System: The UNT Digital Library
Comparison of Sequential Designs of Computer Experiments in High Dimensions (open access)

Comparison of Sequential Designs of Computer Experiments in High Dimensions

None
Date: July 21, 2011
Creator: Kupresanin, A M & Johannesson, G
Object Type: Report
System: The UNT Digital Library
Techniques For Injection Of Pre-Charaterized Dust Into The Scrape Off Layer Of Fusion Plasma (open access)

Techniques For Injection Of Pre-Charaterized Dust Into The Scrape Off Layer Of Fusion Plasma

Introduction of micron-sized dust into the scrape-off layer (SOL) of a plasma has recently found many applications aimed primarily at determining dust behavior in future fusion reactors. The dust particles are typically composed of materials intrinsic to a fusion reactor. On DIII-D and TEXTOR carbon dust has been introduced into the SOL using a probe inserted from below into the divertor region. On NSTX, both Li and tungsten dust have been dropped from the top of the machine into the SOL throughout the duration of a discharge, by utilizing a vibrating piezoelectric based particle dropper. The original particle dropper was developed to inject passivated Li powder {approx} 40 {mu}m in diameter into the SOL to enhance plasma performance. A simplified version of the dropper was developed to introduce trace amounts of tungsten powder for only a few discharges, thus not requiring a large powder reservoir. The particles emit visible light from plasma interactions and can be tracked by either spectroscopic means or by fast frame rate visible cameras. This data can then be compared with dust transport codes such as DUSTT to make predictions of dust behavior in next-step devices such as ITER. For complete modeling results, it is desired …
Date: July 21, 2011
Creator: Roquemore, A. L.; John, B.; Friesen, F.; Hartzfeld, K. & Mansfield, D. K.
Object Type: Report
System: The UNT Digital Library
Gyrokinetics Simulation of Energetic Particle Turbulence and Transport (open access)

Gyrokinetics Simulation of Energetic Particle Turbulence and Transport

Progress in research during this year elucidated the physics of precession resonance and its interaction with radial scattering to form phase space density granulations. Momentum theorems for drift wave-zonal flow systems involving precession resonance were derived. These are directly generalizable to energetic particle modes. A novel nonlinear, subcritical growth mechanism was identified, which has now been verified by simulation. These results strengthen the foundation of our understanding of transport in burning plasmas
Date: September 21, 2011
Creator: Diamond, Patrick H.
Object Type: Report
System: The UNT Digital Library
DuraLith Alkali-Aluminosilicate Geopolymer Waste Form Testing for Hanford Secondary Waste (open access)

DuraLith Alkali-Aluminosilicate Geopolymer Waste Form Testing for Hanford Secondary Waste

The primary objective of the work reported here was to develop additional information regarding the DuraLith alkali aluminosilicate geopolymer as a waste form for liquid secondary waste to support selection of a final waste form for the Hanford Tank Waste Treatment and Immobilization Plant secondary liquid wastes to be disposed in the Integrated Disposal Facility on the Hanford Site. Testing focused on optimizing waste loading, improving waste form performance, and evaluating the robustness of the waste form with respect to waste variability.
Date: July 21, 2011
Creator: Gong, W. L.; Lutz, Werner & Pegg, Ian L.
Object Type: Report
System: The UNT Digital Library
Expanded High-Level Waste Glass Property Data Development: Phase I (open access)

Expanded High-Level Waste Glass Property Data Development: Phase I

Two separate test matrices were developed as part if the EM-21 Glass Matrix Crucible Testing. The first matrix, developed using a single component-at-a-time design method and covering glasses of interest primarily to Hanford, is addressed in this data package. This data package includes methods and results from glass fabrication, chemical analysis of glass compositions, viscosity, electrical conductivity, liquidus temperature, canister centerline cooling, product consistency testing, and the toxicity characteristic leach procedure.
Date: January 21, 2011
Creator: Schweiger, Michael J.; Riley, Brian J.; Crum, Jarrod V.; Hrma, Pavel R.; Rodriguez, Carmen P.; Arrigoni, Benjamin M. et al.
Object Type: Report
System: The UNT Digital Library
FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects (open access)

FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects

The global and annual mean aerosol direct and indirect effects, relative to 1850 conditions, estimated from CESM simulations are 0.02 W m-2 and -0.39 W m-2, respectively, for emissions in year 2100 under the IPCC RCP8.5 scenario. The indirect effect is much smaller than that for 2000 emissions because of much smaller SO2 emissions in 2100; the direct effects are small due to compensation between warming by black carbon and cooling by sulfate.
Date: September 21, 2011
Creator: Koch, D.
Object Type: Text
System: The UNT Digital Library
Study of wavelength-shifting chemicals for use in large-scale water Cherenkov detectors (open access)

Study of wavelength-shifting chemicals for use in large-scale water Cherenkov detectors

Cherenkov detectors employ various methods to maximize light collection at the photomultiplier tubes (PMTs). These generally involve the use of highly reflective materials lining the interior of the detector, reflective materials around the PMTs, or wavelength-shifting sheets around the PMTs. Recently, the use of water-soluble wavelength-shifters has been explored to increase the measurable light yield of Cherenkov radiation in water. These wave-shifting chemicals are capable of absorbing light in the ultravoilet and re-emitting the light in a range detectable by PMTs. Using a 250 L water Cherenkov detector, we have characterized the increase in light yield from three compounds in water: 4-Methylumbelliferone, Carbostyril-124, and Amino-G Salt. We report the gain in PMT response at a concentration of 1 ppm as: 1.88 {+-} 0.02 for 4-Methylumbelliferone, stable to within 0.5% over 50 days, 1.37 {+-} 0.03 for Carbostyril-124, and 1.20 {+-} 0.02 for Amino-G Salt. The response of 4-Methylumbelliferone was modeled, resulting in a simulated gain within 9% of the experimental gain at 1 ppm concentration. Finally, we report an increase in neutron detection performance of a large-scale (3.5 kL) gadolinium-doped water Cherenkov detector at a 4-Methylumbelliferone concentration of 1 ppm.
Date: September 21, 2011
Creator: Sweany, M; Bernstein, A; Dazeley, S; Dunmore, J; Felde, J; Svoboda, R et al.
Object Type: Article
System: The UNT Digital Library
Portal 6.0 Released!! (open access)

Portal 6.0 Released!!

None
Date: March 21, 2011
Creator: Cantor, Michael & Smirnova, Tatyana
Object Type: Article
System: The UNT Digital Library
Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site (open access)

Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site

Previous experiments at the Rifle, Colorado Integrated Field Research Challenge (IFRC) site demonstrated that field-scale addition of acetate to groundwater reduced the ambient soluble uranium concentration. In this report, sediment samples collected before and after acetate field addition were used to assess the active microbes via {sup 13}C acetate stable isotope probing on 3 phases [coarse sand, fines (8-approximately 150 {micro}m), groundwater (0.2-8 {micro}m)] over a 24-day time frame. TRFLP results generally indicated a stronger signal in {sup 13}C-DNA in the 'fines' fraction compared to the sand and groundwater. Before the field-scale acetate addition, a Geobacter-like group primarily synthesized {sup 13}C-DNA in the groundwater phase, an alpha Proteobacterium primarily grew on the fines/sands, and an Acinetobacter sp. and Decholoromonas-like OTU utilized much of the {sup 13}C acetate in both groundwater and particle-associated phases. At the termination of the field-scale acetate addition, the Geobacter-like species was active on the solid phases rather than the groundwater, while the other bacterial groups had very reduced newly synthesized DNA signal. These findings will help to delineate the acetate utilization patterns of bacteria in the field and can lead to improved methods for stimulating distinct microbial populations in situ.
Date: February 21, 2011
Creator: Kerkhof, L.; Williams, K.H.; Long, P.E. & McGuinness, L.
Object Type: Article
System: The UNT Digital Library
Department of Energy – Office of Science Pacific Northwest Site Office Environmental Monitoring Plan for the DOE-SC PNNL Site (open access)

Department of Energy – Office of Science Pacific Northwest Site Office Environmental Monitoring Plan for the DOE-SC PNNL Site

The Pacific Northwest Site Office (PNSO) manages the contract for operations at the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site in Richland, Washington. Radiological operations at the DOE-SC PNNL Site expanded in 2010 with the completion of facilities at the Physical Sciences Facility. As a result of the expanded radiological work at the site, the Washington State Department of Health (WDOH) has required that offsite environmental surveillance be conducted as part of the PNNL Site Radioactive Air Emissions License. The environmental monitoring and surveillance requirements of various orders, regulations, and guidance documents consider emission levels and subsequent risk of negative human and environmental impacts. This Environmental Monitoring Plan (EMP) describes air surveillance activities at the DOE-SC PNNL Site. The determination of offsite environmental surveillance needs evolved out of a Data Quality Objectives process (Barnett et al. 2010) and Implementation Plan (Snyder et al. 2010). The entire EMP is a compilation of several documents, which include the Main Document (this text), Attachment 1: Sampling and Analysis Plan, Attachment 2: Data Management Plan, and Attachment 3: Dose Assessment Guidance.
Date: December 21, 2011
Creator: Snyder, Sandra F.; Meier, Kirsten M.; Barnett, J. M.; Bisping, Lynn E.; Poston, Ted M. & Rhoads, Kathleen
Object Type: Report
System: The UNT Digital Library
Implications of Pulser Voltage Ripple (open access)

Implications of Pulser Voltage Ripple

In a recent set of measurements obtained by G. Kamin, W. Manning, A. Molvik, and J. Sullivan, the voltage waveform of the diode pulser had a ripple of approximately {+-}1.3% of the 65 kV flattop voltage, and the beam current had a larger corresponding ripple of approximately {+-}8.4% of the 1.5 mA average current at the location of the second Faraday cup, approximately 1.9 m downstream from the ion source. The period of the ripple was about 1 {mu}s. It was initially unclear whether this large current ripple was in fact a true measurement of the current or a spurious measurement of noise produced by the pulser electronics. The purpose of this note is to provide simulations which closely match the experimental results and thereby corroborate the physical nature of those measurements, and to provide predictions of the amplitude of the current ripples as they propagate to the end of linear transport section. Additionally analytic estimates are obtained which lend some insight into the nature of the current fluctuations and to provide an estimate of what the maximum amplitude of the current fluctuations are expected to be, and conversely what initial ripple in the voltage source is allowed, given a …
Date: December 21, 2011
Creator: Barnard, J J
Object Type: Report
System: The UNT Digital Library
Annual Report of Groundwater Monitoring at Everest, Kansas, in 2010. (open access)

Annual Report of Groundwater Monitoring at Everest, Kansas, in 2010.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) began its environmental investigations at Everest, Kansas, in 2000. The work at Everest is implemented on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The results of the environmental investigations have been reported in detail (Argonne 2001, 2003, 2006a,b). The lateral extent of the carbon tetrachloride in groundwater over the years of investigation has been interpreted as shown in Figure 1.1 (2001-2002 data), Figure 1.2 (2006 data), Figure 1.3 (2008 data), and Figure 1.4 (2009 data). The pattern of groundwater flow and inferred contaminant migration has consistently been to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property (e.g., Figure 1.5 [2008 data] and Figure 1.6 [2009 data]). Both the monitoring data for carbon tetrachloride and the low groundwater flow rates estimated for the Everest aquifer unit (Argonne 2003, 2006a,b, 2008) indicate slow contaminant migration. On the basis of the accumulated findings, in March 2009 the CCC/USDA developed a plan for annual monitoring of the groundwater and surface water. This current monitoring plan (Appendix A in the report …
Date: March 21, 2011
Creator: Lafreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Tests of Radiation-Hard Silicon Microstrip Sensors for CMS in S-LHC (open access)

Tests of Radiation-Hard Silicon Microstrip Sensors for CMS in S-LHC

The tests are to study the performance of various silicon microstrip sensors that are sufficiently radiation-hard to be considered as candidates for the CMS outer (R > 25cm) tracker in the second phase of the currently envisioned S-LHC upgrade. The main goal of the beam test is to test Float Zone (FZ) and Magnetic Czochralski (MCz) silicon sensors that have been procured from Hamamatsu by the CMS collaboration as possible replacements for the CMS outer tracker for phase 2 operations. The detectors under test (DUT) will be isntalled in a cold box that contains 10 slots for modules based on CMS Tracker hybrids. Slots 1-4 and 7-10 are occupied by reference planes and slots 5 and 6 are reserved for DUTs. The box is cooled by Peltier elements in thermal contact with the top and bottom aluminum baseplates and is typically operated at around -25 C. A PCI based version of the CMS DAQ is used to read out the 10 slots based on triggers provided by beam scintillation counters. Given the low rate of beam particles the hybrid APVs will be operated in Peak mode, which maximizes the signal-to-noise performance of the readout chips. The internal clock operates at …
Date: February 21, 2011
Creator: Luukka, Panja; Maenpaa, Teppo; Tuovinen, Esa; Spiegel, Lenny & Flight, Robert
Object Type: Report
System: The UNT Digital Library
Distinguishing Realistic Military Blasts from Firecrackers in Mitigation Studies of Blast Induced Traumatic Brain Injury (open access)

Distinguishing Realistic Military Blasts from Firecrackers in Mitigation Studies of Blast Induced Traumatic Brain Injury

In their Contributed Article, Nyein et al. (1,2) present numerical simulations of blast waves interacting with a helmeted head and conclude that a face shield may significantly mitigate blast induced traumatic brain injury (TBI). A face shield may indeed be important for future military helmets, but the authors derive their conclusions from a much smaller explosion than typically experienced on the battlefield. The blast from the 3.16 gm TNT charge of (1) has the following approximate peak overpressures, positive phase durations, and incident impulses (3): 10 atm, 0.25 ms, and 3.9 psi-ms at the front of the head (14 cm from charge), and 1.4 atm, 0.32 ms, and 1.7 psi-ms at the back of a typical 20 cm head (34 cm from charge). The peak pressure of the wave decreases by a factor of 7 as it traverses the head. The blast conditions are at the threshold for injury at the front of the head, but well below threshold at the back of the head (4). The blast traverses the head in 0.3 ms, roughly equal to the positive phase duration of the blast. Therefore, when the blast reaches the back of the head, near ambient conditions exist at the …
Date: January 21, 2011
Creator: Moss, W C; King, M J & Blackman, E G
Object Type: Article
System: The UNT Digital Library
Programmable Beam Spatial Shaping System for the National Ignition Facility (open access)

Programmable Beam Spatial Shaping System for the National Ignition Facility

A system of customized spatial light modulators has been installed onto the front end of the laser system at the National Ignition Facility (NIF). The devices are capable of shaping the beam profile at a low-fluence relay plane upstream of the amplifier chain. Their primary function is to introduce 'blocker' obscurations at programmed locations within the beam profile. These obscurations are positioned to shadow small, isolated flaws on downstream optical components that might otherwise limit the system operating energy. The modulators were designed to enable a drop-in retrofit of each of the 48 existing Pre Amplifier Modules (PAMs) without compromising their original performance specifications. This was accomplished by use of transmissive Optically Addressable Light Valves (OALV) based on a Bismuth Silicon Oxide photoconductive layer in series with a twisted nematic liquid crystal (LC) layer. These Programmable Spatial Shaper packages in combination with a flaw inspection system and optic registration strategy have provided a robust approach for extending the operational lifetime of high fluence laser optics on NIF.
Date: January 21, 2011
Creator: Heebner, J.; Borden, M.; Miller, P.; Hunter, S.; Christensen, K.; Scanlan, M. et al.
Object Type: Article
System: The UNT Digital Library
Proof-of-principle experiment for FEL-based coherent electron cooling (open access)

Proof-of-principle experiment for FEL-based coherent electron cooling

Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, high-intensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC. We plan to complete the program in five years. During first two years we will build coherent electron cooler in IP2 of RHIC. In parallel we will develop complete package of computer simulation tools for the start-to-end simulation predicting exact performance of a CeC. The later activity will be the core of Tech X involvement into the project. We will use these tools to predict the performance of our CeC device. The experimental demonstration of the CeC will be undertaken in years three to five of …
Date: August 21, 2011
Creator: Litvinenko, V. N.; Belomestnykh, S.; Ben-Zvi, Ilan; Brutus, J. C.; Fedotov, A.; Hao, Y. et al.
Object Type: Article
System: The UNT Digital Library
Asian-Australian Monsoon Panel Report to the CLIVAR Scientific Steering Group-18 (open access)

Asian-Australian Monsoon Panel Report to the CLIVAR Scientific Steering Group-18

None
Date: April 21, 2011
Creator: Sperber, K R; Hendon, H H & Ereno, C E
Object Type: Report
System: The UNT Digital Library
Membership of the 112th Congress: A Profile (open access)

Membership of the 112th Congress: A Profile

None
Date: June 21, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Brazil’s WTO Case Against the U.S. Cotton Program (open access)

Brazil’s WTO Case Against the U.S. Cotton Program

The so-called "Brazil cotton case" is a long-running World Trade Organization dispute settlement case initiated by Brazil - a major cotton export competitor - in 2002 against specific provisions of the U.S. cotton program. This report details the overview of the case, background on the U.S. cotton sector, Brazil's dispute settlement case against the U.S. cotton program, panel and appellate body recommendations, implementation of those recommendations, World Trade Organization compliance panel review and ruling, and more related to the case.
Date: June 21, 2011
Creator: Schnepf, Randy
Object Type: Report
System: The UNT Digital Library
Egypt in Transition (open access)

Egypt in Transition

This report provides a brief overview of the transition underway and information on U.S. foreign aid to Egypt.
Date: September 21, 2011
Creator: Sharp, Jeremy M.
Object Type: Report
System: The UNT Digital Library
Considerations for a Catastrophic Declaration: Issues and Analysis (open access)

Considerations for a Catastrophic Declaration: Issues and Analysis

This report examines concerns expressed by policymakers and experts that current Stafford Act declarations are inadequate to respond to, and recover from, highly destructive events, and presents the arguments for and against amending the act to add a catastrophic declaration amendment.
Date: June 21, 2011
Creator: Lindsey, Bruce R. & McCarthy, Francis X.
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act (ESA) in the 112th Congress: Conflicting Values and Difficult Choices (open access)

The Endangered Species Act (ESA) in the 112th Congress: Conflicting Values and Difficult Choices

None
Date: March 21, 2011
Creator: Buck, Eugene H.; Corn, M. Lynne; Alexander, Kristina; Sheikh, Pervaze A. & Meltz, Robert
Object Type: Report
System: The UNT Digital Library