2009 Annual Health Physics Report for the HEU Transparency Program (open access)

2009 Annual Health Physics Report for the HEU Transparency Program

During the 2009 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. LLNL also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2009, there were 159 person-trips that required dose monitoring of the U.S. monitors. Of the 159 person-trips, 149 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 4 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. LLNL's Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2009, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency Program now has over fifteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.
Date: April 14, 2010
Creator: Radev, R
Object Type: Report
System: The UNT Digital Library
2D Spatial Frequency Considerations in Comparing 1D Power Spectral Density Measurements (open access)

2D Spatial Frequency Considerations in Comparing 1D Power Spectral Density Measurements

The frequency footprint of ID and 2D profiling instruments needs to be carefully considered in comparing ID surface roughness spectrum measurements made by different instruments. Contributions from orthogonal direction frequency components can not be neglected. The use of optical profiling instruments is ubiquitous in the measurement of the roughness of optical surfaces. Their ease-of-use and non-contact measurement method found widespread use in the optics industry for measuring the quality of delicate optical surfaces. Computerized digital data acquisition with these instruments allowed for quick and easy calculation of surface roughness statistics, such as root-mean-square (RMS) roughness. The computing power of the desktop computer allowed for the rapid conversion of spatial domain data into the frequency domain, enabling the application of sophisticated signal processing techniques to be applied to the analysis of surface roughness, the most powerful of which is the power spectral density (PSP) function. Application of the PSD function to surface statistics introduced the concept of 'bandwidth-limited' roughness, where the value of the RMS roughness depends critically upon the spatial frequency response of the instrument. Different instruments with different spatial frequency response characteristics give different answers when measuring the same surface.
Date: June 14, 2010
Creator: Takacs, P. Z.; Barber, S.; Church, E. L.; Kaznatcheev, K.; McKinney, W. R. & Yashchuk, V. Y.
Object Type: Article
System: The UNT Digital Library

3D Thermal and Electrochemical Model for Spirally Wound Large Format Lithium-ion Batteries

In many commercial cells, long tabs at both cell sides, leading to uniform potentials along the spiral direction of wound jelly rolls, are rarely seen because of their high manufacturing cost. More often, several metal strips are welded at discrete locations along both current collector foils. With this design, the difference of electrical potentials is easily built up along current collectors in the spiral direction. Hence, the design features of the tabs, such as number, location and size, can be crucial factors for spiral-shaped battery cells. This paper presents a Li-ion battery cell model having a 3-dimensional spiral mesh involving a wound jellyroll structure. Further results and analysis will be given regarding impacts of tab location, number, and size.
Date: October 14, 2010
Creator: Lee, K. J.; Kim, G. H. & Smith, K.
Object Type: Presentation
System: The UNT Digital Library
Ab Initio Theory of Light-Ion Reactions (open access)

Ab Initio Theory of Light-Ion Reactions

None
Date: September 14, 2010
Creator: Navratil, P; Quaglioni, S & Roth, R
Object Type: Article
System: The UNT Digital Library
Algorithm for Computation of Electromagnetic Fields of An Accelerated Short Bunch Inside a Rectangular Chamber (open access)

Algorithm for Computation of Electromagnetic Fields of An Accelerated Short Bunch Inside a Rectangular Chamber

We discuss the feasibility of an application of an implicit finite-difference approximation to calculate the fields of a relativistic bunch moving with no restriction inside a vacuum chamber. We assume that a bunch trajectory is not straight but is inside a vacuum chamber or its branch. The bunch can be deflected by the fields of bending magnets. The bunch can be short enough to produce coherent synchrotron radiation (CSR). Accelerator physicists believe that electromagnetic phenomena of charged beams are governed by Maxwell's equations together with Newton's equations for particle dynamics. To understand the behavior of the beams and radiated fields we just need to find a solution to these equations for the case, which can fully describe the real accelerator environment. So, at first we make a model, which contains all the necessary components, but at the same time can be easily 'inserts' into the equations. Sometimes, it is possible to find analytical solutions, but usually they are only work for one-dimensional cases and rarer for two-dimension cases. To find a solution in general we may transform the equations into a equivalent finite-difference form and solve them using computers. We can find a lot of finite-difference schemes, which approximate Maxwell's …
Date: September 14, 2010
Creator: Novokhatski, Alexander & Sullivan, Michael
Object Type: Article
System: The UNT Digital Library
Application for a Permit to Operate a Class III Solid Waste Disposal Site at the Nevada Test Site Area 5 Asbestiform Low-Level Solid Waste Disposal Site (open access)

Application for a Permit to Operate a Class III Solid Waste Disposal Site at the Nevada Test Site Area 5 Asbestiform Low-Level Solid Waste Disposal Site

The NTS solid waste disposal sites must be permitted by the state of Nevada Solid Waste Management Authority (SWMA). The SWMA for the NTS is the Nevada Division of Environmental Protection, Bureau of Federal Facilities (NDEP/BFF). The U.S. Department of Energy's National Nuclear Security Administration Nevada Site Office (NNSA/NSO) as land manager (owner), and National Security Technologies (NSTec), as operator, will store, collect, process, and dispose all solid waste by means that do not create a health hazard, a public nuisance, or cause impairment of the environment. NTS disposal sites will not be included in the Nye County Solid Waste Management Plan. The NTS is located approximately 105 kilometers (km) (65 miles [mi]) northwest of Las Vegas, Nevada (Figure 1). The U.S. Department of Energy (DOE) is the federal lands management authority for the NTS, and NSTec is the Management and Operations contractor. Access on and off the NTS is tightly controlled, restricted, and guarded on a 24-hour basis. The NTS has signs posted along its entire perimeter. NSTec is the operator of all solid waste disposal sites on the NTS. The Area 5 RWMS is the location of the permitted facility for the Solid Waste Disposal Site (SWDS). The …
Date: September 14, 2010
Creator: Programs, NSTec Environmental
Object Type: Report
System: The UNT Digital Library
APPLICATION OF A THIN FILM EVAPORATOR SYSTEM FOR MANAGEMENT OF LIQUID HIGH-LEVEL WASTES AT HANFORD (open access)

APPLICATION OF A THIN FILM EVAPORATOR SYSTEM FOR MANAGEMENT OF LIQUID HIGH-LEVEL WASTES AT HANFORD

A modular, transportable evaporator system, using thin film evaporative technology, is planned for deployment at the Hanford radioactive waste storage tank complex. This technology, herein referred to as a wiped film evaporator (WFE), will be located at grade level above an underground storage tank to receive pumped liquids, concentrate the liquid stream from 1.1 specific gravity to approximately 1.4 and then return the concentrated solution back into the tank. Water is removed by evaporation at an internal heated drum surface exposed to high vacuum. The condensed water stream will be shipped to the site effluent treatment facility for final disposal. This operation provides significant risk mitigation to failure of the aging 242-A Evaporator facility; the only operating evaporative system at Hanford maximizing waste storage. This technology is being implemented through a development and deployment project by the tank farm operating contractor, Washington River Protection Solutions (WRPS), for the Office of River Protection/Department of Energy (ORP/DOE), through Columbia Energy & Environmental Services, Inc. (Columbia Energy). The project will finalize technology maturity and install a system at one of the double-shell tank farms. This paper discusses results of pre-project pilot-scale testing by Columbia Energy and ongoing technology maturation development scope through fiscal …
Date: January 14, 2010
Creator: Tedeschi, A. R. & Wilson, R. A.
Object Type: Article
System: The UNT Digital Library
Approximation Properties of Coarse Spaces by Algebraic Multigrid (open access)

Approximation Properties of Coarse Spaces by Algebraic Multigrid

None
Date: January 14, 2010
Creator: Vassilevski, P. S.
Object Type: Article
System: The UNT Digital Library
Beam Conditioning for Free Electron Lasers:Consequences and Methods (open access)

Beam Conditioning for Free Electron Lasers:Consequences and Methods

The consequences of beam conditioning in four example cases [VISA, a soft x-ray free-electron laser (FEL), LCLS, and a 'Greenfield' FEL] are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse emittance and, furthermore, allows for stronger focusing in the undulator. Simulations show higher saturation power, with gain lengths reduced by a factor of 2 or more. The beam dynamics in a general conditioning system are studied, with 'matching conditions' derived for achieving conditioning without growth in the effective emittance. Various conditioning lattices are considered, and expressions derived for the amount of conditioning provided in each case when the matching conditions are satisfied. These results show that there is no fundamental obstacle to producing beam conditioning, and that the problem can be reduced to one of proper lattice design. Nevertheless, beam conditioning will not be easy to implement in practice.
Date: December 14, 2010
Creator: Wolski, A.; Penn, G.; Sessler, A.; Wurtele, J. & /LBL, Berkeley /UC, Berkeley, Astron. Dept.
Object Type: Article
System: The UNT Digital Library
A Benchmark Comparison of Monte Carlo Particle Transport Algorithms for Binary Stochastic Mixtures (open access)

A Benchmark Comparison of Monte Carlo Particle Transport Algorithms for Binary Stochastic Mixtures

None
Date: May 14, 2010
Creator: Brantley, P
Object Type: Article
System: The UNT Digital Library
Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA (open access)

Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA

Benzene, a ubiquitous human carcinogen, forms DNA adducts through its metabolites such as p-benzoquinone (p-BQ) and hydroquinone (HQ). N(2)-(4-Hydroxyphenyl)-2'-deoxyguanosine (N(2)-4-HOPh-dG) is the principal adduct identified in vivo by (32)P-postlabeling in cells or animals treated with p-BQ or HQ. To study its effect on repair specificity and replication fidelity, we recently synthesized defined oligonucleotides containing a site-specific adduct using phosphoramidite chemistry. We here report the repair of this adduct by Escherichia coli UvrABC complex, which performs the initial damage recognition and incision steps in the nucleotide excision repair (NER) pathway. We first showed that the p-BQ-treated plasmid was efficiently cleaved by the complex, indicating the formation of DNA lesions that are substrates for NER. Using a 40-mer substrate, we found that UvrABC incises the DNA strand containing N(2)-4-HOPh-dG in a dose- and time-dependent manner. The specificity of such repair was also compared with that of DNA glycosylases and damage-specific endonucleases of E. coli, both of which were found to have no detectable activity toward N(2)-4-HOPh-dG. To understand why this adduct is specifically recognized and processed by UvrABC, molecular modeling studies were performed. Analysis of molecular dynamics trajectories showed that stable G:C-like hydrogen bonding patterns of all three Watson-Crick hydrogen bonds are …
Date: June 14, 2010
Creator: Hang, Bo; Rodriguez, Ben; Yang, Yanu; Guliaev, Anton B. & Chenna, Ahmed
Object Type: Article
System: The UNT Digital Library
Business Continuity Planning Resources for Small- and Medium-Sized Businesses (open access)

Business Continuity Planning Resources for Small- and Medium-Sized Businesses

This document/memo summarizes existing resources and guidance on business continuity planning for small- to medium-sized businesses. DTRA will share this information with large commercial businesses who identified the need to help their suppliers and other key collaborators prepare business continuity plans in order to speed recovery from a wide-area bioterrorism incident.
Date: May 14, 2010
Creator: Judd, Kathleen S. & Lesperance, Ann M.
Object Type: Report
System: The UNT Digital Library
California GAMA Special Study: An isotopic and dissolved gas investigation of nitrate source and transport to a public supply well in California's Central Valley (open access)

California GAMA Special Study: An isotopic and dissolved gas investigation of nitrate source and transport to a public supply well in California's Central Valley

This study investigates nitrate contamination of a deep municipal drinking water production well in Ripon, CA to demonstrate the utility of natural groundwater tracers in constraining the sources and transport of nitrate to deep aquifers in the Central Valley. The goal of the study was to investigate the origin (source) of elevated nitrate and the potential for the deep aquifer to attenuate anthropogenic nitrate. The site is ideal for such an investigation. The production well is screened from 165-325 feet below ground surface and a number of nearby shallow and deep monitoring wells were available for sampling. Furthermore, potential sources of nitrate contamination to the well had been identified, including a fertilizer supply plant located approximately 1000 feet to the east and local almond groves. A variety of natural isotopic and dissolved gas tracers including {sup 3}H-{sup 3}He groundwater age and the isotopic composition of nitrate are applied to identify nitrate sources and to characterize nitrate transport. An advanced method for sampling production wells is employed to help identify contaminant contributions from specific screen intervals. Nitrate transport: Groundwater nitrate at this field site is not being actively denitrified. Groundwater parameters indicate oxic conditions, the dissolved gas data shows no evidence …
Date: April 14, 2010
Creator: Singleton, M. J.; Moran, J. E.; Esser, B. K.; Roberts, S. K. & Hillegonds, D. J.
Object Type: Report
System: The UNT Digital Library
Characterization of Second Harmonic Afterburner Radiation at the LCLS (open access)

Characterization of Second Harmonic Afterburner Radiation at the LCLS

During commissioning of the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Laboratory it was shown that saturation lengths much shorter than the installed length of the undulator line can routinely be achieved. This frees undulator segments that can be used to provide enhanced spectral properties and at the same time, test the concept of FEL Afterburners. In December 2009 a project was initiated to convert undulator segments at the down-beam end of the undulator line into Second Harmonic Afterburners (SHAB) to enhance LCLS radiation levels in the 10-20 keV energy range. This is being accomplished by replacement of gap-shims increasing the fixed gaps from 6.8 mm to 9.9 mm, which reduces their K values from 3.50 to 2.25 and makes the segments resonant at the second harmonic of the upstream unmodified undulators. This paper reports experimental results of the commissioning of the SHAB extension to LCLS.
Date: September 14, 2010
Creator: Nuhn, Heinz-Dieter
Object Type: Article
System: The UNT Digital Library
Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro (open access)

Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro

The major goal of this study is to determine the effects of the Fhit pathway on low dose (< 0.1 Gy) ionizing radiation (IR)-induced genetic instability. Reduction of Fhit protein expression is observed in most solid tumors particularly in those tumors resulting from exposure to environmental carcinogens. Therefore, characterization of the role of the Fhit-dependent pathway in preventing low dose IR-induced genetic instability will provide useful parameters for evaluating the low dose IR-induced risk of mutagenesis and carcinogenesis. We pursued 3 specific aims to study our hypothesis that the Fhit-dependent pathways maintain genomic integrity through adjusting checkpoint response and repair genes expression following low dose IR. Aim 1: Determine whether Fhit interaction with RPA is necessary for Fhit to affect the cellular response to low dose IR. We combined the approaches of in vitro (GST pull-down and site-directed mutagenesis) and in vivo (observing the co-localization and immunoprecipitation of Fhit and RPA in Fhit knock out mouse cells transfected with mutant Fhit which has lost ability to interact with RPA in vitro). Aim 2: Determine the role of genes whose expression is affected by Fhit in low dose irradiated cells. We analyzed the distinct signature of gene expression in low dose …
Date: May 14, 2010
Creator: Wang, Ya
Object Type: Report
System: The UNT Digital Library
Chemical Dynamics, Molecular Energetics, and Kinetics at the Synchrotron (open access)

Chemical Dynamics, Molecular Energetics, and Kinetics at the Synchrotron

Scientists at the Chemical Dynamics Beamline of the Advanced Light Source in Berkeley are continuously reinventing synchrotron investigations of physical chemistry and chemical physics with vacuum ultraviolet light. One of the unique aspects of a synchrotron for chemical physics research is the widely tunable vacuum ultraviolet light that permits threshold ionization of large molecules with minimal fragmentation. This provides novel opportunities to assess molecular energetics and reaction mechanisms, even beyond simple gas phase molecules. In this perspective, significant new directions utilizing the capabilities at the Chemical Dynamics Beamline are presented, along with an outlook for future synchrotron and free electron laser science in chemical dynamics. Among the established and emerging fields of investigations are cluster and biological molecule spectroscopy and structure, combustion flame chemistry mechanisms, radical kinetics and product isomer dynamics, aerosol heterogeneous chemistry, planetary and interstellar chemistry, and secondary neutral ion-beam desorption imaging of biological matter and materials chemistry.
Date: March 14, 2010
Creator: Leone, Stephen R.; Ahmed, Musahid & Wilson, Kevin R.
Object Type: Article
System: The UNT Digital Library
Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows (open access)

Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows

Gas-particle flows in fluidized beds and riser reactors are inherently unstable, and they manifest fluctuations over a wide range of length and time scales. Two-fluid models for such flows reveal unstable modes whose length scale is as small as ten particle diameters. Yet, because of limited computational resources, gas-particle flows in large fluidized beds are invariably simulated by solving discretized versions of the two-fluid model equations over a coarse spatial grid. Such coarse-grid simulations do not resolve the small-scale spatial structures which are known to affect the macroscale flow structures both qualitatively and quantitatively. Thus there is a need to develop filtered two-fluid models which are suitable for coarse-grid simulations and capturing the effect of the small-scale structures through closures in terms of the filtered variables. The overall objective of the project is to develop validated closures for filtered two-fluid models for gas-particle flows, with the transport gasifier as a primary, motivating example. In this project, highly resolved three-dimensional simulations of a kinetic theory based two-fluid model for gas-particle flows have been performed and the statistical information on structures in the 100-1000 particle diameters length scale has been extracted. Based on these results, closures for filtered two-fluid models have been …
Date: February 14, 2010
Creator: Sundaresan, Sankaran
Object Type: Report
System: The UNT Digital Library
CO-PRODUCT ENHANCEMENT AND DEVELOPMENT FOR THE MASADA OXYNOL PROCESS PROCESS (open access)

CO-PRODUCT ENHANCEMENT AND DEVELOPMENT FOR THE MASADA OXYNOL PROCESS PROCESS

The focus of this project was an overall process improvement through the enhancement of the co-product streams. The enhancement of the process operations and co-products will increase both ethanol production and the value of other process outputs and reduces the amount of waste byproducts. This leads to a more economical and environmentally sound alternative to landfill disposal of municipal solid waste (MSW). These enhancements can greatly increase the commercial potential for the production of ethanol from MSW by the Masada CES OxyNol process. Both technological and economical issues were considered for steps throughout the conversion process. The research efforts of this project are varied but synergistic. The project investigated many of the operations involved in the Masada process with the overall goal of process improvements. The general goal of the testing was to improve co-product quality, improve conversions efficiencies, minimize process losses, increase energy efficiency, and mitigate process and commercialization risks. The project was divided into 16 subtasks as described in general terms below. All these tasks are interrelated but not necessarily interdependent.
Date: June 14, 2010
Creator: Watkins, Donald V.
Object Type: Report
System: The UNT Digital Library
CO2-driven Enhanced Oil Recovery as a Stepping Stone to What? (open access)

CO2-driven Enhanced Oil Recovery as a Stepping Stone to What?

This paper draws heavily on the authors’ previously published research to explore the extent to which near term carbon dioxide-driven enhanced oil recovery (CO2-EOR) can be “a stepping stone to a long term sequestration program of a scale to be material in climate change risk mitigation.” The paper examines the historical evolution of CO2-EOR in the United States and concludes that estimates of the cost of CO2-EOR production or the extent of CO2 pipeline networks based upon this energy security-driven promotion of CO2-EOR do not provide a robust platform for spurring the commercial deployment of carbon dioxide capture and storage technologies (CCS) as a means of reducing greenhouse gas emissions. The paper notes that the evolving regulatory framework for CCS makes a clear distinction between CO2-EOR and CCS and the authors examine arguments in the technical literature about the ability for CO2-EOR to generate offsetting revenue to accelerate the commercial deployment of CCS systems in the electric power and industrial sectors of the economy. The authors conclude that the past 35 years of CO2-EOR in the U.S. have been important for boosting domestic oil production and delivering proven system components for future CCS systems. However, though there is no reason …
Date: July 14, 2010
Creator: Dooley, James J.; Dahowski, Robert T. & Davidson, Casie L.
Object Type: Report
System: The UNT Digital Library
CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase (open access)

CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase

Project attempts to develop a synthetic analogue for carbonic anhydrase and incorporate it in a membrane for separation of CO2 from coal power plant flue gas. Conference poster presents result of first 9 months of project progress including concept, basic system architecture and membrane properties target, results of molecular modeling for analogue - CO2 interaction, and next steps of testing analogue resistance to flue gas contaminants.
Date: September 14, 2010
Creator: Cordatos, Harry
Object Type: Article
System: The UNT Digital Library
COG - Special Features of Interest to Criticality Safety Practitioners (open access)

COG - Special Features of Interest to Criticality Safety Practitioners

COG is a modern, general-purpose, high fidelity, multi-particle transport code developed at the Lawrence Livermore National Laboratory specifically for use in deep penetration (shielding) and criticality safety calculations. This paper describes some features in COG of special interest to criticality safety practitioners.
Date: January 14, 2010
Creator: Buck, R M; Heinrichs, D P; Krass, A W & Lent, E M
Object Type: Article
System: The UNT Digital Library
Coherent Radiation Effects in the LCLS Undulator (open access)

Coherent Radiation Effects in the LCLS Undulator

For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting …
Date: December 14, 2010
Creator: Reiche, S.; /UCLA & Huang, Z.
Object Type: Article
System: The UNT Digital Library
Comparison of Demand Response Performance with an EnergyPlus Model in a Low Energy Campus Building (open access)

Comparison of Demand Response Performance with an EnergyPlus Model in a Low Energy Campus Building

We have studied a low energy building on a campus of the University of California. It has efficient heating, ventilation, and air conditioning (HVAC) systems, consisting of a dual-fan/dual-duct variable air volume (VAV) system. As a major building on the campus, it was included in two demand response (DR) events in the summers of 2008 and 2009. With chilled water supplied by thermal energy storage in the central plant, cooling fans played a critical role during DR events. In this paper, an EnergyPlus model of the building was developed and calibrated. We compared both whole-building and HVAC fan energy consumption with model predictions to understand why demand savings in 2009 were much lower than in 2008. We also used model simulations of the study building to assess pre-cooling, a strategy that has been shown to improve demand saving and thermal comfort in many types of building. This study indicates a properly calibrated EnergyPlus model can reasonably predict demand savings from DR events and can be useful for designing or optimizing DR strategies.
Date: May 14, 2010
Creator: Dudley, Junqiao Han; Black, Doug; Apte, Mike; Piette, Mary Ann & Berkeley, Pam
Object Type: Article
System: The UNT Digital Library
A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber (open access)

A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber

An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life …
Date: January 14, 2010
Creator: C.A. Gentile, W.R. Blanchard, T.A. Kozub, M. Aristova, C. McGahan, S. Natta, K. Pagdon, J. Zelenty
Object Type: Report
System: The UNT Digital Library