Absorber height effects on SWA restrictions and 'Shadow' LER (open access)

Absorber height effects on SWA restrictions and 'Shadow' LER

As extreme-ultraviolet lithography (EUVL) approaches introduction at the 22-nm half-pitch node, several key aspects of absorber height effects remain unexplored. In particular, sidewall angle (SWA) restrictions based on the height of the mask absorber has not yet been clearly defined. In addition, the effects of absorber height on line-edge roughness (LER) from shadowing has not been examined. We make an initial investigation into how tight SWA constraints are and the extent to which shadow LER alters basic LER. Our approach to SWA aims to find SWA restrictions based on 10% of the total CD error budget (10% of CD). Thus, we allot the SWA budget a {+-}0.2nm tolerance for 22nm half-pitch. New with EUVL is the off-axis illumination system. One potential pitfall that must be carefully monitored is the effect of mask absorber height blocking light from reaching, and therefore, correctly detecting, the base edge position of a feature. While mask features can correctly compensate sizing to target at the wafer, the effects of this shadowing on LER have not yet been investigated. Specifically, shadow LER may exacerbate or mitigate the inherent LER on the mask. Shadowing may also cause a difference in the observed LER on the right and …
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
Object Type: Article
System: The UNT Digital Library
Lessons Learned From an Installation Perspective for Chemicaal Demilitarization Plant Start-Up at Four Operating Incineration Sites. (open access)

Lessons Learned From an Installation Perspective for Chemicaal Demilitarization Plant Start-Up at Four Operating Incineration Sites.

This study presents the lessons learned by chemical storage installations as they prepared for the start of chemical demilitarization plant operations at the four current chemical incinerator sites in Alabama, Arkansas, Oregon, and Utah. The study included interviews with persons associated with the process and collection of available documents prepared at each site. The goal was to provide useful information for the chemical weapons storage sites in Colorado and Kentucky that will be going through plant start-up in the next few years. The study is not a compendium of what to do and what not to do. The information has been categorized into ten lessons learned; each is discussed individually. Documents that may be useful to the Colorado and Kentucky sites are included in the appendices. This study should be used as a basis for planning and training.
Date: February 21, 2011
Creator: Motz, L. & Sciences, Decision and Information
Object Type: Report
System: The UNT Digital Library
Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2011 (open access)

Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2011

This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2011 and includes inspection and repair activities completed at the following CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 453: Area 9 UXO Landfill (TTR); and (5) CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Appendix B. The inspection checklists are included in Appendix C, field notes are included in Appendix D, and photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted May 3 and 4, 2011. Maintenance was performed at CAU 424, CAU 453, and CAU 487. At CAU 424, two surface grade monuments at Landfill Cell A3-3 could not be located during the inspection. The two monuments were located and marked with lava rock on July 13, 2011. At CAU 453, there was evidence of animal burrowing. Animal burrows were …
Date: February 21, 2012
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Characterization of Group V Dubnium Homologs on DGA Extraction Chromatography Resin from Nitric and Hydrofluoric Acid Matrices (open access)

Characterization of Group V Dubnium Homologs on DGA Extraction Chromatography Resin from Nitric and Hydrofluoric Acid Matrices

Studies of the chemical properties of superheavy elements (SHE) pose interesting challenges due to their short half-lives and low production rates. Chemical systems must have extremely fast kinetics, fast enough kinetics to be able to examine the chemical properties of interest before the SHE decays to another nuclide. To achieve chemistry on such time scales, the chemical system must also be easily automated. Most importantly however, a chemical system must be developed which provides suitable separation and kinetics before an on-line study of a SHE can be performed. Relativistic effects make studying the chemical properties of SHEs interesting due to the impact these effects could have on the SHEs chemical properties. Relativistic effects arise when the velocity of the s orbital electrons approach the speed of light. As this velocity increases, the Bohr radius of the inner electron orbitals decreases and there is an increase in the particles mass. This contraction results in a destabilization of the energy of the outer d and f electron orbitals (5f and 6d in the case of SHE), which can cause these to expand due to their increased shielding from the nuclear charge. Another relativistic effect is the spin-orbit splitting for p, d, and …
Date: February 21, 2012
Creator: Despotopulos, J D & Sudowe, R
Object Type: Report
System: The UNT Digital Library
WRPS MEETING THE CHALLENGE OF TANK WASTE (open access)

WRPS MEETING THE CHALLENGE OF TANK WASTE

Washington River Protection Solutions (WRPS) is the Hanford tank operations contractor, charged with managing one of the most challenging environmental cleanup projects in the nation. The U.S. Department of Energy hired WRPS to manage 56 million gallons of high-level radioactive waste stored in 177 underground tanks. The waste is the legacy of 45 years of plutonium production for the U. S. nuclear arsenal. WRPS mission is three-fold: safely manage the waste until it can be processed and immobilized; develop the tools and techniques to retrieve the waste from the tanks, and build the infrastructure needed to deliver the waste to the Waste Treatment Plant (WTP) when it begins operating. WTP will 'vitrify' the waste by mixing it with silica and other materials and heating it in an electric melter. Vitrification turns the waste into a sturdy glass that will isolate the radioactivity from the environment. It will take more than 20 years to process all the tank waste. The tank waste is a complex highly radioactive mixture of liquid, sludge and solids. The radioactivity, chemical composition of the waste and the limited access to the underground storage tanks makes retrieval a challenge. Waste is being retrieved from aging single-shell tanks …
Date: February 21, 2012
Creator: JC, BRITTON
Object Type: Article
System: The UNT Digital Library
DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID (open access)

DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID

The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO{sub 2}) using Phase II of HB-Line. To support the new mission, the development of a Pu metal dissolution flowsheet which utilizes concentrated (8-10 M) nitric acid (HNO{sub 3}) solutions containing potassium fluoride (KF) is required. Dissolution of Pu metal in concentrated HNO{sub 3} is desired to eliminate the need to adjust the solution acidity prior to purification by anion exchange. The preferred flowsheet would use 8-10 M HNO{sub 3}, 0.015-0.07 M KF, and 0.5-1.0 g/L Gd to dissolve the Pu up to 6.75 g/L. An alternate flowsheet would use 8-10 M HNO{sub 3}, 0.1-0.2 M KF, and 1-2 g/L B to dissolve the Pu. The targeted average Pu metal dissolution rate is 20 mg/min-cm{sup 2}, which is sufficient to dissolve a 'standard' 2250-g Pu metal button in 24 h. Plutonium metal dissolution rate measurements showed that if Gd is used as the nuclear poison, the optimum dissolution conditions occur in 10 M HNO{sub 3}, 0.04-0.05 M KF, and 0.5-1.0 g/L Gd at 112 to 116 C (boiling). These conditions will result in an estimated Pu metal dissolution rate of {approx}11-15 mg/min-cm{sup …
Date: February 21, 2012
Creator: Rudisill, Tracy S. & Pierce, R.
Object Type: Report
System: The UNT Digital Library
A Study of the Effects of Different Urban Wind Models on Dispersion Patterns Using Joint Urban 2003 Data (open access)

A Study of the Effects of Different Urban Wind Models on Dispersion Patterns Using Joint Urban 2003 Data

The Quick Urban & Industrial Complex (QUIC) Dispersion Modeling System has been developed to rapidly compute the transport and dispersion of toxic agent releases in the vicinity of buildings. It is composed of a wind solver, an 'urbanized' Lagrangian random-walk model, and a graphical user interface. QUIC has two different wind models: (a) The QUIC-URB wind solver, an empirically-based diagnostic wind model and (b) The QUIC-CFD (RANS) solver, based on the 3D Reynolds-Averaged Navier-Stokes (RANS) equations. In this paper, we discuss the effect of different wind models on dispersion patterns in dense built-up areas. The model-computed wind from the two urban wind models- QUIC-URB and QUIC-CFD are used to drive the dispersion model. The concentration fields are then compared to measurements from the Oklahoma City Joint Urban 2003 field experiment. QUIC produces high-resolution 3-D mean wind and concentration fields around buildings, in addition to deposition on the ground and building surfaces. It has options for different release types, including point, moving point, line, area, and volumetric sources, as well as dense gas, explosive buoyant rise, multi-particle size, bioslurry, and two-phase releases. Other features include indoor infiltration, a pressure solver, outer grid simulations, vegetative canopies, and population exposure calculations. It has …
Date: February 21, 2012
Creator: Gowardhan, A A & Brown, M J
Object Type: Article
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
ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #120111 (open access)

ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #120111

Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.120111 qualification and the first 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Analyses of Pail 125 verification sample fails the criteria for solids content and has measurably lower pH, density, and total bottle weight. The verification sample for Pail 125 was retested for weight percent solids after checking that all of the solids had been suspended. The sample again failed to meet acceptance criteria. SRNL recommends accepting Pails 1 through 120. Pails 121 through 125 should be rejected and returned to the vendor.
Date: February 21, 2012
Creator: Shehee, T.
Object Type: Report
System: The UNT Digital Library
LER control and mitigation: mask roughness induced LER (open access)

LER control and mitigation: mask roughness induced LER

In the push towards commercialization of extreme-ultraviolet lithography (EUVL), meeting the stringent requirements for line-edge roughness (LER) is increasingly challenging. For the 22-nm half-pitch node and below, the ITRS requires under 1.2 nm LER. Much of this LER is thought to arise from three significant contributors: LER on the mask absorber pattern, LER from the resist, and LER from mask roughness induced speckle. The physical mechanism behind the last contributor is becoming clearer, but how it is affected by the presence of aberrations is less well understood. Here, we conduct a full 2D aerial image simulation analysis of aberrations sensitivities of mask roughness induced LER for the first 37 fringe zernikes. These results serve as a guideline for future LER aberrations control. In examining how to mitigate mask roughness induced LER, we next consider an alternate illumination scheme whereby a traditional dipole's angular spectrum is extended in the direction parallel to the line-and-space mask absorber pattern to represent a 'strip'. While this illumination surprisingly provides merely minimal improvement to the LER as several alternate illumination schemes, overall imaging quality in terms of ILS, NILS, and contrast is improved. While the 22-nm half-pitch node can tolerate significant aberrations from a mask …
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
Object Type: Article
System: The UNT Digital Library
Computational Nanophotonics: Model Optical Interactions and Transport in Tailored Nanosystem Architectures (open access)

Computational Nanophotonics: Model Optical Interactions and Transport in Tailored Nanosystem Architectures

The program is directed toward development of new computational approaches to photoprocesses in nanostructures whose geometry and composition are tailored to obtain desirable optical responses. The emphasis of this specific program is on the development of computational methods and prediction and computational theory of new phenomena of optical energy transfer and transformation on the extreme nanoscale (down to a few nanometers).
Date: February 21, 2014
Creator: Stockman, Mark & Gray, Steven
Object Type: Report
System: The UNT Digital Library
Exploding Pressure Vessel Test of YBaCuO HTS Pancakes (open access)

Exploding Pressure Vessel Test of YBaCuO HTS Pancakes

N/A
Date: February 21, 2013
Creator: Witte, Holger; Lalitha, Lakshmi; Gupta, Ramesh; Lewin, Richard; Jones, Harry & Hickman, Anthony
Object Type: Report
System: The UNT Digital Library
Application of Ensemble Sensitivity Analysis to Observation Targeting for Short-term Wind Speed Forecasting (open access)

Application of Ensemble Sensitivity Analysis to Observation Targeting for Short-term Wind Speed Forecasting

The operators of electrical grids, sometimes referred to as Balancing Authorities (BA), typically make critical decisions on how to most reliably and economically balance electrical load and generation in time frames ranging from a few minutes to six hours ahead. At higher levels of wind power generation, there is an increasing need to improve the accuracy of 0- to 6-hour ahead wind power forecasts. Forecasts on this time scale have typically been strongly dependent on short-term trends indicated by the time series of power production and meteorological data from a wind farm. Additional input information is often available from the output of Numerical Weather Prediction (NWP) models and occasionally from off-site meteorological towers in the region surrounding the wind generation facility. A widely proposed approach to improve short-term forecasts is the deployment of off-site meteorological towers at locations upstream from the wind generation facility in order to sense approaching wind perturbations. While conceptually appealing, it turns out that, in practice, it is often very difficult to derive significant benefit in forecast performance from this approach. The difficulty is rooted in the fact that the type, scale, and amplitude of the processes controlling wind variability at a site change from day …
Date: February 21, 2010
Creator: Zack, J; Natenberg, E; Young, S; Manobianco, J & Kamath, C
Object Type: Report
System: The UNT Digital Library
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

This report serves as a primer on the European Union and provides a brief description of U.S.-EU relations that may be of interest in the 114th Congress.
Date: February 21, 2017
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
Legislative Branch: FY2017 Appropriations (open access)

Legislative Branch: FY2017 Appropriations

The first section of this report provides an overview of the consideration of fiscal year 2017 legislative branch appropriations, with subsections covering each action. It is followed by a section on prior year actions and funding, which contains historical tables. The report then addresses the FY2017 budget requests, requested administrative language, and selected funding issues for individual legislative branch agencies and entities.
Date: February 21, 2017
Creator: Brudnick, Ida A.
Object Type: Report
System: The UNT Digital Library
Current Ballistic Missile Defense (BMD) Issues (open access)

Current Ballistic Missile Defense (BMD) Issues

This report discusses the missile defense program and whether current policy or program direction might change. The FY2017 National Defense Authorization Act (NDAA, P.L. 114-328) made several notable changes that could have significant effects on the direction of U.S. BMD policy and programs.
Date: February 21, 2017
Creator: Hildreth, Steven A.
Object Type: Report
System: The UNT Digital Library
Nonstrategic Nuclear Weapons (open access)

Nonstrategic Nuclear Weapons

This report provides basic information about U.S. and Russian nonstrategic nuclear weapons. It reviews the issues that have been raised with regard to U.S. and Russian nonstrategic nuclear weapons, and summarizes a number of policy options that might be explored by Congress, the United States, Russia, and other nations to address these issues.
Date: February 21, 2017
Creator: Woolf, Amy F.
Object Type: Report
System: The UNT Digital Library
A New Authorization for Use of Military Force Against the Islamic State: Issues and Current Proposals (open access)

A New Authorization for Use of Military Force Against the Islamic State: Issues and Current Proposals

This report focuses on several proposals for a new Authorization for Use of Military Force (AUMF) specifically targeting the Islamic State made during the 113th and 114th Congresses. It includes a brief review of existing authorities and AUMFs, as well as a discussion of issues related to various provisions included in existing and proposed AUMFs that both authorize and limit presidential use of military force. Appendices provide a comparative analysis of similar provisions in new AUMFs proposed in the 113th and 114th Congresses. This report will be updated to reflect congressional activity.
Date: February 21, 2017
Creator: Weed, Matthew C.
Object Type: Report
System: The UNT Digital Library
Journal of the House of Representatives of Texas: 82nd Legislature, Regular Session, Monday, February 21, 2011 (open access)

Journal of the House of Representatives of Texas: 82nd Legislature, Regular Session, Monday, February 21, 2011

Proceedings of the House of Representatives of Texas for the twenty-second day of the regular session of the 82nd Legislature documenting legislation, reports, discussions, votes, and points-of-order.
Date: February 21, 2011
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
Focus Report, Volume 85, Number 2, February 21, 2017 (open access)

Focus Report, Volume 85, Number 2, February 21, 2017

"This report summarizes the key constitutional provisions and rules governing bills in the Legislature, with an emphasis on House rules."
Date: February 21, 2017
Creator: Texas. Legislature. House of Representatives. Research Organization.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Civil-Suit Provision in House-Passed Concealed Carry Reciprocity Bill (H.R. 38): Scope and Application (open access)

Civil-Suit Provision in House-Passed Concealed Carry Reciprocity Bill (H.R. 38): Scope and Application

This report discusses legal implications of the Concealed Carry Reciprocity Act of 2017 which was passed by the House in December 2017.
Date: February 21, 2018
Creator: Peck, Sarah Herman
Object Type: Report
System: The UNT Digital Library
The Joint Select Committee on Budget and Appropriations Process Reform (open access)

The Joint Select Committee on Budget and Appropriations Process Reform

This report discusses the structure, powers, and funding of the Joint Select Committee on Budget and Appropriations Process Reform and provides an overview of the parliamentary procedures the chambers may use to consider its recommendations.
Date: February 21, 2018
Creator: Lynch, Megan S. & Saturno, James V.
Object Type: Report
System: The UNT Digital Library
U.S. Manufacturing in International Perspective (open access)

U.S. Manufacturing in International Perspective

This report is designed to inform the debate over the health of U.S. manufacturing through a series of charts and tables that depict the position of the United States relative to other countries according to various metrics. This report does not describe or discuss specific policy options.
Date: February 21, 2018
Creator: Levinson, Marc
Object Type: Report
System: The UNT Digital Library
Defense Science and Technology Funding (open access)

Defense Science and Technology Funding

This report provides an overview of the portion of Department of Defense (DOD) research, development, testing, and evaluation (RDT&E) funding referred to as Defense Science and Technology (Defense S&T). It provides perspectives on the role of Defense S&T in supporting U.S. defense capabilities, historical funding levels, recent funding trends, and approaches to determining how much the federal government should invest in Defense S&T, particularly in basic research.
Date: February 21, 2018
Creator: Sargent, John F.
Object Type: Report
System: The UNT Digital Library