Micropulse Lidar Cloud Mask Value-Added Product Technical Report (open access)

Micropulse Lidar Cloud Mask Value-Added Product Technical Report

Lidar backscattered signal is a useful tool for identifying vertical cloud structure in the atmosphere in optically thin clouds. Cloud boundaries derived from lidar signals are a necessary input for popular ARM data products, such as the Active Remote Sensing of Clouds (ARSCL) product. An operational cloud boundary algorithm (Wang and Sassen 2001) has been implemented for use with the ARM Micropulse Lidar (MPL) systems. In addition to retrieving cloud boundaries above 500 m, the value-added product (VAP) named Micropulse Lidar Cloud Mask (MPLCMASK) applies lidar-specific corrections (i.e., range-square, background, deadtime, and overlap) as described in Campbell et al. (2002) to the measured backscattered lidar. Depolarization ratio is computed using the methodology developed by Flynn et al. (2007) for polarization-capable MPL systems. The cloud boundaries output from MPLCMASK will be the primary lidar cloud mask for input to the ARSCL product and will be applied to all MPL systems, including historical data sets.
Date: July 25, 2011
Creator: Sivaraman, C & Comstock, J
Object Type: Report
System: The UNT Digital Library
MPO B593110 - Final Report (open access)

MPO B593110 - Final Report

National Security Technologies, LLC (NSTec) shall provide one (1) Mechanical Engineer to support the Linear Collider Subsystem Development Program at Lawrence Livermore National Security, LLC (LLNS). The NSTec Mechanical Engineer's efforts will include engineering, design, and drawing support for the Vacuum Seal Test. NSTec will also provide a final report of the setup and input to LLNL's project management on project status. The NSTec Mechanical Engineer's efforts will also include engineering, design, and drawing support to the conceptual design for manufacturing of the Flux Concentrator Magnet. NSTec will also contribute to LLNS's final report on the Flux Concentrator Magnet. The deliverables are drawings, sketches, engineering documents, and final reports delivered to the LLNS Technical Representative.
Date: July 25, 2011
Creator: Brooksby, C
Object Type: Report
System: The UNT Digital Library
MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2) (open access)

MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2)

This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility microwave radiometer (MWR) Retrieval (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).
Date: July 25, 2011
Creator: Gaustad, K. L.; Turner, D. D. & McFarlane, S. A.
Object Type: Report
System: The UNT Digital Library
National Ignition Facility and Managing Location, Component, and State (open access)

National Ignition Facility and Managing Location, Component, and State

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system coupled with a 10-meter diameter target chamber. There are over 6,200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1,200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, …
Date: July 25, 2011
Creator: Foxworthy, C.; Fung, T.; Beeler, R.; Li, J.; Dugorepec, J. & Chang, C.
Object Type: Article
System: The UNT Digital Library
Novel deflecting cavity design for eRHIC (open access)

Novel deflecting cavity design for eRHIC

To prevent significant loss of the luminosity due to large crossing angle in the future ERL based Electron Ion Collider at BNL (eRHIC), there is a demand for crab cavities. In this article, we will present a novel design of the deflecting/crabbing 181 MHz superconducting RF cavity that will fulfil the requirements of eRHIC. The quarter-wave resonator structure of the new cavity possesses many advantages, such as compact size, high R{sub t}/Q, the absence of the same order mode and lower order mode, and easy higher order mode damping. We will present the properties and characteristics of the new cavity in detail. As the accelerator systems grow in complexity, developing compact and efficient deflecting cavities is of great interest. Such cavities will benefit situations where the beam line space is limited. The future linac-ring type electron-ion collider requires implementation of a crab-crossing scheme for both beams at the interaction region. The ion beam has a long bunches and high rigidity. Therefore, it requires a low frequency, large kicking angle deflector. The frequency of the deflecting mode for the current collider design is 181 MHz, and the deflecting angle is {approx}5 mrad for each beam. At such low frequency, the previous …
Date: July 25, 2011
Creator: Wu, Q.; Belomestnykh, S. & Ben-Zvi, Ilan
Object Type: Article
System: The UNT Digital Library
Oracle Database DBFS Hierarchical Storage Overview (open access)

Oracle Database DBFS Hierarchical Storage Overview

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory creates large numbers of images during each shot cycle for the analysis of optics, target inspection and target diagnostics. These images must be readily accessible once they are created and available for the 30 year lifetime of the facility. The Livermore Computing Center (LC) runs a High Performance Storage System (HPSS) that is capable of storing NIF's estimated 1 petabyte of diagnostic images at a fraction of what it would cost NIF to operate its own automated tape library. With Oracle 11g Release 2 database, it is now possible to create an application transparent, hierarchical storage system using the LC's HPSS. Using the Oracle DBMS-LOB and DBMS-DBFS-HS packages a SecureFile LOB can now be archived to storage outside of the database and accessed seamlessly through a DBFS 'link'. NIF has chosen to use this technology to implement a hierarchical store for its image based SecureFile LOBs. Using a modified external store and DBFS links, files are written to and read from a disk 'staging area' using Oracle's backup utility. Database external procedure calls invoke OS based scripts to manage a staging area and the transfer of the backup files …
Date: July 25, 2011
Creator: Rivenes, A
Object Type: Article
System: The UNT Digital Library
Radoptic x-ray detection with picosecond resolution (open access)

Radoptic x-ray detection with picosecond resolution

None
Date: July 25, 2011
Creator: Lowry, M. E.; Vernon, S. P.; Steele, P. T.; Bennett, C. V.; Hernandez, V. J.; Moran, B. et al.
Object Type: Article
System: The UNT Digital Library
Shot Planning and Analysis Tools (open access)

Shot Planning and Analysis Tools

Shot planning and analysis tools (SPLAT) integrate components necessary to help achieve a high over-all operational efficiency of the National Ignition Facility (NIF) by combining near and long-term shot planning, final optics demand and supply loops, target diagnostics planning, and target fabrication requirements. Currently, the SPLAT project is comprised of two primary tool suites for shot planning and optics demand. The shot planning component provides a web-based interface to selecting and building a sequence of proposed shots for the NIF. These shot sequences, or 'lanes' as they are referred to by shot planners, provide for planning both near-term shots in the Facility and long-term 'campaigns' in the months and years to come. The shot planning capabilities integrate with the Configuration Management Tool (CMT) for experiment details and the NIF calendar for availability. Future enhancements will additionally integrate with target diagnostics planning and target fabrication requirements tools. The optics demand component is built upon predictive modelling of maintenance requirements on the final optics as a result of the proposed shots assembled during shot planning. The predictive models integrate energetics from a Laser Performance Operations Model (LPOM), the status of the deployed optics as provided by the online Final Optics Inspection system, …
Date: July 25, 2011
Creator: Casey, A.; Beeler, R.; Conder, A.; Fallejo, R.; Flegel, M.; Hutton, M. et al.
Object Type: Article
System: The UNT Digital Library
Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility (open access)

Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility

The National Ignition Facility (NIF) is the world's largest laser composed of millions of individual parts brought together to form one massive assembly. Maintaining control of the physical definition, status and configuration of this structure is a monumental undertaking yet critical to the validity of the shot experiment data and the safe operation of the facility. The NIF business application suite of software provides the means to effectively manage the definition, build, operation, maintenance and configuration control of all components of the National Ignition Facility. State of the art Computer Aided Design software applications are used to generate a virtual model and assemblies. Engineering bills of material are controlled through the Enterprise Configuration Management System. This data structure is passed to the Enterprise Resource Planning system to create a manufacturing bill of material. Specific parts are serialized then tracked along their entire lifecycle providing visibility to the location and status of optical, target and diagnostic components that are key to assessing pre-shot machine readiness. Nearly forty thousand items requiring preventive, reactive and calibration maintenance are tracked through the System Maintenance & Reliability Tracking application to ensure proper operation. Radiological tracking applications ensure proper stewardship of radiological and hazardous materials and …
Date: July 25, 2011
Creator: Dobson, D.; Churby, A.; Krieger, E.; Maloy, D. & White, K.
Object Type: Article
System: The UNT Digital Library
Spectral amplitude and phase evolution in multi-petawatt laserpulses (open access)

Spectral amplitude and phase evolution in multi-petawatt laserpulses

None
Date: July 25, 2011
Creator: Filip, C V
Object Type: Article
System: The UNT Digital Library
Superconducting 112 MHz QWR electron gun (open access)

Superconducting 112 MHz QWR electron gun

Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also …
Date: July 25, 2011
Creator: Belomestnykh, S.; Ben-Zvi, Ilan; Boulware, C. H.; Chang, X.; Grimm, T. L.; Rao, T. et al.
Object Type: Article
System: The UNT Digital Library
Survey of SRF guns (open access)

Survey of SRF guns

Developing Superconducting RF (SRF) electron guns is an active field with several laboratories working on different gun designs. While the first guns were based on elliptic cavity geometries, Quarter Wave Resonator (QWR) option is gaining popularity. QWRs are especially well suited for producing beams with high charge per bunch. In this talk we will describe recent progress in developing both types of SRF guns. SRF guns made excellent progress in the last two years. Several guns generated beams and one, at HZDR, injected beam into an accelerator. By accomplishing this, HZDR/ELBE gun demonstrated feasibility of the SRF gun concept with a normal-conducting Cs{sub 2}Te cathode. The cathode demonstrated very good performance with the lifetime of {approx}1 year. However, for high average current/high bunch charge operation CsK{sub 2}Sb is preferred as it needs green lasers, unlike UV laser for the Cs{sub 2}Te, which makes it easier to build laser/optics systems. Other high QE photocathodes are being developed for SRF guns, most notably diamond-amplified photocathode. Several QWR guns are under development with one producing beam already. They are very promising for high bunch charge operation. The field is very active and we should expect more good results soon.
Date: July 25, 2011
Creator: Belomestnykh, S.
Object Type: Article
System: The UNT Digital Library
TOF-SIMS Analysis of Hydrogen in Niobium, From 160 deg. K to 475 deg. K (open access)

TOF-SIMS Analysis of Hydrogen in Niobium, From 160 deg. K to 475 deg. K

Niobium (Nb) is the material of choice for superconducting radio frequency (SRF) cavities due to its high critical temperature and critical magnetic field. Interstitial impurity elements such as H directly influence the efficiency of these cavities. Quantification of H in Nb is difficult since H is extremely mobile in Nb with a very high diffusion coefficient even at room temperature. In the presented work, Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was used to characterize H in Nb over a wide temperature range (160°K to 475°K) in situ to check for changes in mobility. Multiple experiments showed that as the specimen temperature is decreased below 300 °K, the H/Nb intensity changes by first increasing and then decreasing drastically at temperatures below 200°K. As specimen temperature is increased from 300°K to 450°K, the H/Nb intensity decreases. Remarkably, the H intensity with respect to Nb increases with time at 475°K (approximately 200°C). Correlation between this data and the H-Nb phase diagram appears to account for the H behaviour.
Date: July 25, 2011
Creator: P. Maheshwari, A.D. Batchelor, D.P. Griffis, F.A. Stevie, C. Zhou, G. Ciovati, R. Myneni, M. Rigsbee
Object Type: Article
System: The UNT Digital Library
Use of the target diagnostic control system in the National Ignition Facility (open access)

Use of the target diagnostic control system in the National Ignition Facility

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated, time resolved and gated X-ray sensors, laser velocity interferometry, and neutron time of flight. Diagnostics to diagnose fusion ignition implosion and neutron emissions have been developed. A Diagnostic Control System (DCS) for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost Window XP processor and Java application. Instruments are aggregated as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. During the past several years, over thirty-six diagnostics have been deployed using this architecture in support of the National Ignition Campaign (NIC). The DCS architecture facilitates the expected additions and upgrades to diagnostics as more experiments are performed. This paper presents the DCS architecture, framework and our experiences in using it during the NIC to operate, upgrade and maintain a large set of diagnostic instruments.
Date: July 25, 2011
Creator: Shelton, R; Lagin, L & Nelson, J
Object Type: Article
System: The UNT Digital Library
X-ray imaging in an environment with high-neutron background on National Ignition Facility (open access)

X-ray imaging in an environment with high-neutron background on National Ignition Facility

None
Date: July 25, 2011
Creator: Smalyuk, V A; Ayers, J; Bell, P M; Bourgade, J -; Bradley, D K; Celeste, J et al.
Object Type: Article
System: The UNT Digital Library
Neutron Compound Refractive Prisms - DOE SBIR Phase II Final Report (open access)

Neutron Compound Refractive Prisms - DOE SBIR Phase II Final Report

The results of the research led to a pulsed electromagnetic periodic magnetic field array (PMF), which coupled with a pair of collimation slits, and a mechanical chopper slit, were able to deflect spin-up neutrons to a band of line-fused neutrons a focal plane heights that correspond to the time-varying magnetic field amplitude. The electromagnetic field PMF produced 5.4 pulses per minute in which each pulse was 50 msec in duration with a full width half maximum (FWHM) of 7.5 msec. The calculated 7.7 mm vertical height of the band of focused spin-up neutrons corresponded closely to the measured 7.5 mm height of the center line of the imaged band of neutrons. The band of deflected spin-up neutrons was 5 mm in vertical width and the bottom of the band was 5 mm above the surface of the PMF pole. The limited exposure time of 3 hours and the smaller 0.78 T magnetic field allowed focused and near focused neutrons of 1.8 àto 2.6 àneutrons, which were in the tails of the McClellan Nuclear Radiation Center Bay 4 Maxwell Boltzmann distribution of neutrons with peak flux at 1.1-1.2 à. The electromagnetic PMF was expected to produces a 2.0 …
Date: June 25, 2011
Creator: Dr. Jay Theodore Cremer, Jr
Object Type: Report
System: The UNT Digital Library
Annual Report of Monitoring at Barnes, Kansas, in 2010 (open access)

Annual Report of Monitoring at Barnes, Kansas, in 2010

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, in 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). The results of that investigation indicated that carbon tetrachloride contamination is present in groundwater at low to moderate levels in the vicinity of the former CCC/USDA grain storage facility. Information obtained during the 2006-2007 investigation also indicated that at least one other potential source might have contributed to the groundwater contaminant plume (Argonne 2008a). The former agriculture building owned by the local school district, located immediately east of well PWS3, is also a potential source of the contamination. In November 2007, the CCC/USDA began periodic groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, under the direction of the Kansas Department of Health and Environment (KDHE). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. Through 2010, sampling was conducted in …
Date: May 25, 2011
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
AT4-CS Final Update (open access)

AT4-CS Final Update

None
Date: May 25, 2011
Creator: Moss, W. C.; Anderson, A. T. & Vignes, R. M.
Object Type: Report
System: The UNT Digital Library
B Lifetimes and X,Y,Z States at the Tevatron (open access)

B Lifetimes and X,Y,Z States at the Tevatron

A measurement of b-hadron lifetimes in the fully reconstructed decay modes B{sup +} {yields} J/{psi}K{sup +}, B{sup 0} {yields} J/{psi}K*{sup 0}, B{sup 0} {yields} J/{psi}K{sub S}{sup 0}, and {Lambda}{sub b}{sup 0} {yields} J/{psi} {Lambda}{sup 0} is reported using data corresponding to an integrated luminosity of 4.3 fb{sup -1}, collected by the CDF II detector at the Fermilab Tevatron. The measured values are {tau}(B{sup +}) = 1.639 {+-} 0.009(stat) {+-} 0.009(syst) ps, {tau}(B{sup 0}) = 1.507 {+-} 0.010(stat) {+-} 0.008(syst) ps and {tau}({Lambda}{sub b}{sup 0}) = 1.537 {+-} 0.045(stat) {+-} 0.014(syst) ps. The lifetime ratios are {tau}(B{sup +})/{tau}(B{sup 0}) - 1.088 {+-} 0.009(stat) {+-} 0.004(syst) and {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 1.020 {+-} 0.030(stat) {+-} 0.008(syst). These are the most precise measurements of these quantities from a single experiment. Observation is also reported for a structure near the J/{psi}{phi} threshold, in B{sup +} to J/{psi}{phi}K{sup +} decays with an integrated luminosity of 6.0 fb{sup -1} and a statistical significance of 5 standard deviations. There are 19 {+-} 6 events observed for this structure at a mass of 4143.4{sub -3.0}{sup +2.9} {+-} 0.6 MeV/c{sup 2} and a width of 15.3{sub -6.1}{sup +10.4} {+-} 2.5 MeV/c{sup 2}.
Date: May 25, 2011
Creator: Fernandez, Juan Pablo
Object Type: Article
System: The UNT Digital Library
DE-FG02-04ER25606 Identity Federation and Policy Management Guide: Final Report (open access)

DE-FG02-04ER25606 Identity Federation and Policy Management Guide: Final Report

The goal of this 3-year project was to facilitate a more productive dynamic matching between resource providers and resource consumers in Grid environments by explicitly specifying policies. There were broadly two problems being addressed by this project. First, there was a lack of an Open Grid Services Architecture (OGSA)-compliant mechanism for expressing, storing and retrieving user policies and Virtual Organization (VO) policies. Second, there was a lack of tools to resolve and enforce policies in the Open Services Grid Architecture. To address these problems, our overall approach in this project was to make all policies explicit (e.g., virtual organization policies, resource provider policies, resource consumer policies), thereby facilitating policy matching and policy negotiation. Policies defined on a per-user basis were created, held, and updated in MyPolMan, thereby providing a Grid user to centralize (where appropriate) and manage his/her policies. Organizationally, the corresponding service was VOPolMan, in which the policies of the Virtual Organization are expressed, managed, and dynamically consulted. Overall, we successfully defined, prototyped, and evaluated policy-based resource management and access control for OGSA-based Grids. This DOE project partially supported 17 peer-reviewed publications on a number of different topics: General security for Grids, credential management, Web services/OGSA/OGSI, policy-based grid authorization …
Date: May 25, 2011
Creator: Humphrey, Marty, A
Object Type: Report
System: The UNT Digital Library
Final Scientific Report (open access)

Final Scientific Report

Hackensack University Medical Center's major initiative to create a cleaner healthier and safer environment for patients, employees and the community served by the medical center is built on its commitment to protect the environment and conserve precious energy resources. Since 2004 the Medical Center launched a long term campaign to temper the negative environmental impact of proposed and existing new construction at the medical center and to improve campus wide overall energy efficiency. The plan was to begin by implementing a number of innovative and eco-friendly enhancements to the Gabrellian Women's and Children's Pavilion, in construction at the time, which would lead to Certification by the US Green Building Councils Leadership & Environmental Design (LEED) program. In addition the medical center would evaluate the feasibility of implementing a photovoltaic system in the new construction (in development and planned) to provide clean pollution free electricity. The steps taken to achieve this included conducting a feasibility study complete with architectural and engineering assessments to determine the potential for implementation of a photovoltaic system on the campus and also to conduct an energy survey that would focus on determining specific opportunities and upgrades that would lead to a healthier energy efficient interior environment …
Date: May 25, 2011
Creator: Lutwick, Suzanne & Cunning, Helen
Object Type: Report
System: The UNT Digital Library
Nuclear Nonproliferation and Arms Control Primer Prepared for the Blue Ribbon Commission on America’s Nuclear Future (open access)

Nuclear Nonproliferation and Arms Control Primer Prepared for the Blue Ribbon Commission on America’s Nuclear Future

To provide a brief overview of key arms control and nonproliferation arrangements for the layperson that may be relevant to the Commission's comprehensive review of policies for managing the back end of the nuclear fuel cycle. Primer would be published by the Commission and made publicly available, probably as an appendix to a larger Commission report.
Date: May 25, 2011
Creator: Williams, Laura S.
Object Type: Report
System: The UNT Digital Library
Optimization of Operating Parameters for Minimum Mechanical Specific Energy in Drilling (open access)

Optimization of Operating Parameters for Minimum Mechanical Specific Energy in Drilling

Efficiency in drilling is measured by Mechanical Specific Energy (MSE). MSE is the measure of the amount of energy input required to remove a unit volume of rock, expressed in units of energy input divided by volume removed. It can be expressed mathematically in terms of controllable parameters; Weight on Bit, Torque, Rate of Penetration, and RPM. It is well documented that minimizing MSE by optimizing controllable factors results in maximum Rate of Penetration. Current methods for computing MSE make it possible to minimize MSE in the field only through a trial-and-error process. This work makes it possible to compute the optimum drilling parameters that result in minimum MSE. The parameters that have been traditionally used to compute MSE are interdependent. Mathematical relationships between the parameters were established, and the conventional MSE equation was rewritten in terms of a single parameter, Weight on Bit, establishing a form that can be minimized mathematically. Once the optimum Weight on Bit was determined, the interdependent relationship that Weight on Bit has with Torque and Penetration per Revolution was used to determine optimum values for those parameters for a given drilling situation. The improved method was validated through laboratory experimentation and analysis of published …
Date: May 25, 2011
Creator: Hamrick, Todd
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction (open access)

Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction

Characteristic K-α x-rays used for single-pulse XRD are conventionally produced by a 37-stage high-voltage Marx pulse generator coupled to a vacuum needle-and-washer x-ray diode via coaxial transmission line. A large field-of-view x-ray image plate detection system typically enables observation of several Debye-Scherrer rings. Recently, we have developed a fiber-optic reducer, coupled to a CCD camera, to obtain low-noise, large field-of-view images. The direct beam spot is produced by bremsstrahlung radiation attenuated by a twomillimeter tungsten beam stop. Determination of the direct beam position is necessary to perform the ring integration.
Date: May 25, 2011
Creator: Morgan, Dane V.
Object Type: Article
System: The UNT Digital Library