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Theory for laser-induced breakdown over vaporizing target surface

Description: A simple but accurate theoretical model is developed to describe the growth of avalanche ionization (breakdown) in the blowoff vapor from a laser-irradiated surface. This nonequilibrium model is applicable to laser intensities and wavelengths from approximately 10/sup 7/ to 10/sup 12/ ..mu..m/sup 2/.W/cm/sup 2/ for lambda/sub L//sup 2/.I/sub 0/, the square of the laser wavelength times its peak intensity. The model pertains only to the early stages of laser-target interaction, from the time surface vaporization begins to when first-degree ionization is achieved in the vapor. Approximate analytical solutions are found for the basic differential equations of the model, and such key quantities as breakdown time and threshold values of laser fluence and intensity are expressed in terms of simple formulas. With the model, we can thus easily predict general trends and specific parametric dependences. The analytical solutions are shown to agree well with accurate numerical solutions of the model's equations and with documented data on CO/sub 2/ laser-induced breakdown over aluminum targets.
Date: December 1, 1977
Creator: Harrach, R.J.
Partner: UNT Libraries Government Documents Department

Laser-accelerated disks for EOS studies

Description: An indirect method of laser-based equation of state studies, which utilizes shock waves generated by laser-accelerated projectiles rather than ablation shocks from direct laser irradiation of the sample under investigation, is proposed and examined theoretically. We derive simple formulas for the minimum thickness and maximum speed of laser-accelerated disks, comparing them with results of Nd-laser experiments conducted by the Naval Research Laboratory. Our calculations indicate that disks can be accelerated to velocities above 10/sup 7/ cm/s using a wide choice of laser parameters (pulse duration, energy, intensity, wavelength, etc.). The use of shorter wavelengths, e.g., a KrF(0.25 ..mu..m) laser rather than Nd (1.06 ..mu..m), allows thicker disks to be accelerated and faster velocities to be attained, approximately in the ratio (lambda/sub L/(Nd)/lambda/sub L/(KrF))/sup 1/3/ approx. = 1.6. One-dimensional Lasnex computer calculations indicate that the laser-accelerated disk constitutes a useful flyer plate even while disassembling under the force of the laser ablation shock. The calculations predict that the shockwave the projectile disk generates in a second (impact) disk located a suitable distance away has a greater amplitude than the laser shock and is considerably more steady, exhibiting little decay in propagating through the second disk.
Date: September 1, 1981
Creator: Harrach, R.J. & Szoke, A.
Partner: UNT Libraries Government Documents Department

Environmental Report 1996, Volume 2

Description: This is Volume 2 of the Lawrence Livermore National Laboratory`s (LLNL`s) annual Environmental Report 1996, prepared for the US Department of Energy. Volume 2 supports Volume 1 summary data and is essentially a detailed data report that provides individual data points, where applicable. Volume 2 includes information on monitoring of air, air effluents, sewerable water, surface water, ground water, soil and sediment, vegetation and foodstuff, environmental radiation, and quality assurance.
Date: January 1, 1996
Creator: Harrach, R.J.
Partner: UNT Libraries Government Documents Department

Inertial effects in laser-driven ablation

Description: The gasdynamic partial differential equations (PDE's) governing the motion of an ablatively accelerated target (rocket) contain an inertial force term that arises from acceleration of the reference frame in which the PDE's are written. We give a simple, intuitive description of this effect, and estimate its magnitude and parametric dependences by means of approximate analytical formulas inferred from our computer hydrocode calculations. Often this inertial term is negligible, but for problems in the areas of laser fusion and laser equation of state studies we find that it can substantially reduce the attainable hydrodynamic efficiency of acceleration and implosion.
Date: July 15, 1983
Creator: Harrach, R.J.; Szeoke, A. & Howard, W.M.
Partner: UNT Libraries Government Documents Department

Inertial effects in laser-driven ablation

Description: The gasdynamic partial differential equations (PDE's) governing the motion of an ablatively accelerated target (rocket) contain an inertial force term that arises mathematically from acceleration of the reference frame in which the PDE's are written, and more physically from the requirement that part of the ablated mass (the deflagration wave zone) needs to be accelerated along with the unablated mass (payload). We give a simple, intuitive description of this effect, and estimate its magnitude and parametric dependences by means of approximate analytical formulas inferred from our computer hydrocode calculations. Often this inertial term is negligible, but for problems in the areas of laser fusion and laser equation of state studies we find that it can reduce the attainable hydrodynamic efficiency of acceleration and implosion by up to 25% for typical conditions.
Date: August 18, 1983
Creator: Harrach, R. J.; Szoeke, A. & Howard, W. M.
Partner: UNT Libraries Government Documents Department

Environmental Report 1995. Volume 1

Description: This report contains the results of Lawrence Livermore National Laboratory`s (LLNL) environmental monitoring and compliance effort and an assessment of the impact of LLNL operations on the environment and the public. This first volume describes LLNL`s environmental impact and compliance activities and features descriptive and explanatory text, summary data tables, and plots showing data trends. The summary data include measures of the center of data, their spread or variability, and their extreme values. Chapters on monitoring air, sewage, surface water, ground water, soil and sediment, vegetation and foodstuff, and environmental radiation are present.
Date: September 1, 1996
Creator: Harrach, R.J.; Failor, R.A. & Gallegos, G.M.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs 1995 annual report

Description: This annual report is prepared pursuant to the National Emissions Standards for Hazardous Air Pollutants (NESHAPs) 40 CFR Part 61, Subpart H; Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an effective dose equivalent (EDE) of 10 mrem to any member of the public. This document contains the EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from 1995 operations.
Date: June 1, 1996
Creator: Gallegos, G.M.; Harrach, R.J.; Biermann, A.H. & Tate, P.J.
Partner: UNT Libraries Government Documents Department

Environmental Report 1996

Description: This summary provides an overview of LLNL`s environmental activities in 1996, including radiological and nonradiological surveillance, effluent and compliance monitoring, remediation, assessment of radiological releases and doses, and determination of the impact of LLNL operations on the environment and public health.
Date: January 1, 1996
Creator: Harrach, R.J.
Partner: UNT Libraries Government Documents Department

Environmental report 1995. Volume 2

Description: This is Volume 2 of the Lawrence Livermore National Laboratory`s (LLNL`s) annual Environmental Report 1995. This volume is intended to support summary data from Volume 1 and is essentially a detailed data report that provides additional data points, where applicable. Some summary data are also included in Volume 2, and more detailed accounts are given of sample collection and analytical methods. Volume 2 includes information in eight chapters on monitoring of air, air effluent, sewage, surface water, ground water, soil and sediment, vegetation and foodstuff, and environmental radiation, as well as three chapters on ground water protection, compliance self-monitoring and quality assurance.
Date: September 1, 1996
Creator: Harrach, R.J.; Failor, R.A. & Gallegos, G.M.
Partner: UNT Libraries Government Documents Department

Environmental Report 1994, Volume No. 1

Description: Lawrence Livermore National Laboratory (LLNL), a U.S. Department of Energy (DOE) facility operated by the University of California, serves as a national resource of scientific, technical, and engineering capability. The Laboratory`s mission focuses on nuclear weapons and national security, and over the years has been broadened to include areas such as strategic defense, energy, the environment, biomedicine, technology transfer, the economy, and education. The Laboratory carries out this multifaceted mission in compliance with local, state, and federal environmental regulatory requirements. It does so with the support of the Environmental Protection Department, which is responsible for environmental monitoring and analysis, hazardous waste management, environmental restoration, and ensuring compliance with environmental laws and regulations. LLNL comprises two sites: the Livermore site and Site 300. The Livermore site occupies an area of 3.28 square kilometers on the eastern edge of Livermore, California. Site 300, LLNL`s experimental testing site, is located 24 kilometers to the east in the Altamont Hills, and occupies an area of 30.3 square kilometers. Environmental monitoring activities are conducted at both sites as well as in surrounding areas. This summary provides an overview of LLNL`s environmental activities in 1994, including radiological and nonradiological sampling and surveillance monitoring, remediation, assessment of radiological releases and doses, and determination of the impact of LLNL operations on the environment and public health.
Date: September 1, 1995
Creator: Rath, K.S.; Harrach, R.J.; Gallegos, G.M. & Failor, R.A.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs Project 1994 Annual Report

Description: The NESHAPs standared in 40 CFR part 61, Subpart H limites the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem to any member of the public. The EDEs to the LLNL site-wide maximally exposed member of the public from 1994 operations were: Livermore 0.065 mrem; site 300 - 0.081 mrem. A complete LLNL-wide radionuclide-inventory update was conducted for 1994. Inventory and site-specific meteorological data, together with results from continuous-monitoring systems, were used as inputs to the EPA-approved CAP88-PC air-dispersion/dose-assessment model to calculate the reported EDEs.
Date: June 1, 1995
Creator: Surano, K.A.; Biermann, A.H. & Harrach, R.J.
Partner: UNT Libraries Government Documents Department

Barriers to communication and cooperation in addressing community impacts of radioactive releases from research facilities.

Description: Two instances of research facilities responding to public scrutiny will be discussed. The first concerns emissions from a �tritium labeling facility� operated at Lawrence Berkeley National Laboratory (LBNL); the second deals with releases of plutonium from Lawrence Livermore National Laboratory (LLNL). There are many parallels between these two cases, both of which are still ongoing. In both, the national laboratory is the acknowledged source of low-level (by regulatory standards) radioactive contamination in the community. A major purpose of both investigations is to determine the degree of the contamination and the threat it poses to public health and the environment. The examining panel or committee is similarly constituted in the two cases, including representatives from all four categories of stakeholders: decision makers; scientists and other professionals doing the analysis/assessment; environmental activist or public interest groups; and �ordinary� citizens (nearly everyone else not in one or more of the first three camps). Both involved community participation from the beginning. The levels of outrage over the events triggering the assessment are comparable; though �discovered� or �appreciated� only a few years ago, the release of radiation in both cases occurred or began occurring more than a decade ago. The meetings have been conducted in a similar manner, with comparable frequency, often utilizing the services of professional facilitators. In both cases, the sharply contrasting perceptions of risk commonly seen between scientists and activists were present from the beginning, though the contrast was sharper and more problematical in the Berkeley case. Yet, the Livermore case seems to be progressing towards a satisfactory resolution, while the Berkeley case remains mired in ill-will, with few tangible results after two years of effort. We perceive a wide gap in negotiation skills (at the very least), and a considerable difference in willingness to compromise, between the environmental activist groups participating ...
Date: May 5, 1999
Creator: Harrach, R J & Peterson, S
Partner: UNT Libraries Government Documents Department

Environmental report 1994. Volume No. 2

Description: This volume 2 of the Lawrence Livermore National Laboratory`s (LLNL`s) annual Environmental Report 1994 is a detailed data report that provides individual data points, where applicable, along with some summary data and more detailed accounts of sample collection and analytical methods. Six chapters have information on monitoring of air, surface water, groundwater, soil and sediment, vegetation and foodstuffs, and environmental radiation; two other chapters cover compliance sel-monitoring and quality assurance.
Date: September 1995
Creator: Rath, Karen S.; Harrach, R. J.; Gallegos, G. M.; Failor, R. A. & Christofferson, E.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs 2003 Annual Report

Description: This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2003 are summarized here. Livermore site: 0.044 mrem (0.44 {micro}Sv) (55% from point-source emissions, 45% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes. Site 300: 0.017 mrem (0.17 {micro}Sv) (98% from point-source emissions, 2% from diffuse-source emissions). The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose-assessment model, except for doses for two diffuse sources that were estimated using measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.
Date: June 23, 2004
Creator: Harrach, R J; Gallegos, G M; Peterson, S; Wilson, K R; Althouse, P E; Larson, J M et al.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs 2004 Annual Report

Description: This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities.
Date: June 27, 2005
Creator: Harrach, R; Gallegos, G; Peterson, R; Wilson, K; Harrach, R J; Gallegos, G M et al.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs 2001 Annual Report

Description: NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2001 are summarized here: (1) Livermore site: 0.017 mrem (0.17 {micro}Sv) (34% from point-source emissions, 66% from diffuse-source emissions), The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes; and (2) Site 300: 0.054 mrem (0.54 {micro}Sv) (93% from point-source emissions, 7% from diffuse-source emissions); The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose assessment model, except for doses for three diffuse sources, which were calculated from measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.
Date: June 18, 2002
Creator: Harrach, R.J.; Peterson, S.-R.; Gallegos, G.M.; Tate, P.J.; Bertoldo, N.A. & Althouse, P.E.
Partner: UNT Libraries Government Documents Department

LLNL NESHAP's 1999 Annual Report

Description: This annual report is prepared pursuant to the National Emissions Standards for Hazardous Air Pollutants (NESHAPs) 40 CFR Part 61, Subpart H; Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from 1999 operations are summarized.
Date: June 1, 2000
Creator: Gallegos, G.; Biermann, A.H.; Harrach, R.J.; Bertoldo, N.A.; Berger, R.L. & Surano,K.A.
Partner: UNT Libraries Government Documents Department

Contrasts in one- and two-dimensional hydrocode calculations of laser-generated shockwaves in disk targets

Description: A comparison is made between 1D and 2D hydrocode calculations and some recent experimental results on laser-driven planar shockwaves in disk targets. A simple model is described which accounts for the trends seen in the calculations and which gives insight into the regime of laser intensity and pulse duration where two-dimensional effects become significant in these experiments.
Date: June 22, 1981
Creator: Harrach, R.J.; Lee, Y.T.; Trainor, R.J.; Holmes, N.C.; Rosen, M.D.; Banner, D.L. et al.
Partner: UNT Libraries Government Documents Department

Site Annual Environmental Report for 1997 - Data Supplement

Description: This Data Supplement to the Lawrence Livermore National Laboratory's (LLNL's) annual Environmental Report 1997 (called Volume 2 in previous years) was prepared for the U.S. Department of Energy. The main volume is intended to provide all information on LLNL's environmental impact and compliance activities that is of interest to most readers. The Data Supplement supports main volume summary data and is essentially a detailed data report that provides individual data points, where applicable. Some summary data are also included in the Data Supplement, and more detailed accounts are given of sample collection and analytical methods. Not all of the data in the Data Supplement tables have been reduced to the proper number of significant figures; however, summary data in both volumes are expressed using the proper number of significant figures. The two volumes are organized in a parallel fashion to aid the reader in cross-referencing between them. This supplement includes more detailed information to support the nine chapters in the main volume that cover monitoring of air, air effluent, sewerable water, surface water, ground water, soil and sediment, vegetation and foodstuff, environmental radiation, and quality assurance. The other four chapters in the main volume have no supporting information in the Data Supplement. As in our previous annual reports, data are presented in Systeme International (SI) units. In particular, the primary units used for radiological results are becquerels and sieverts for activity and dose, with curies and rem used secondarily (1 Bq = 2.7 x 10{sup {minus}11} Ci; 1 Sv = 100 rem).
Date: September 1, 1998
Creator: Biermann, A.H.; Althouse, P.E.; Brandstetter, E.R.; Christofferson, E.C.; Fields, B.C.; Gallegos, G.M. et al.
Partner: UNT Libraries Government Documents Department

Site Annual Environmental Report for 1997 - Executive Summary

Description: The Environmental Report 1997 is prepared for the U.S. Department of Energy (DOE), as required by DOE Order 5400.1 and DOE Order 231.1, by the Environmental Protection Department (EPD) at the Lawrence Livermore National Laboratory (LLNL). The results of LLNL's environmental monitoring and compliance effort and an assessment of the impact of LLNL operations on the environment and the public are presented in this publication.
Date: September 1, 1998
Creator: Biermann, A.H.; Althouse, P.E; Brandstetter, E.R.; Christofferson, E.C.; Fields, B.C.; Gallegos, G.M. et al.
Partner: UNT Libraries Government Documents Department

Site Annual Environmental Report for 1997 (SAER)

Description: The Environmental Report 1997 is prepared for the U.S. Department of Energy (DOE), as required by DOE Order 5400.1 and DOE Order 231.1, by the Environmental Protection Department (EPD) at the Lawrence Livermore National Laboratory (LLNL). The results of LLNL's environmental monitoring and compliance effort and an assessment of the impact of LLNL operations on the environment and the public are presented in this publication.
Date: September 1, 1998
Creator: Biermann, A.H.; Althouse, P.E; Brandstetter, E.R.; Christofferson, E.C.; Fields, B.C.; Gallegos, G.M. et al.
Partner: UNT Libraries Government Documents Department

LLNL NESHAPs 1998 annual report

Description: This annual report is prepared pursuant to the National Emissions Standards for Hazardous Air Pollutants (NESHAPs) 40 CFR Part 61, Subpart H; Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from 1998 operations are summarized here. (1) Livermore site: 0.055 mrem (0.55 {micro}Sv) (57% from point-source emissions, 43% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX and is used for compliance purposes. LLNL believes a more realistic dose for the Livermore site is 0.049 mrem (0.49 {micro}Sv) (52% from point-source emissions, 48% from diffuse-source emissions). This dose is based on an assessment that represents a more realistic behavior of tritium gas in the environment. (2) Site 300: 0.024 mrem (0.24 {micro}Sv) (78% from point-source emissions, 22% from diffuse-source emissions). The EDEs were generally calculated using the EPA-approved CAP88-PC air-dispersion/dose-assessment model. Site-specific meteorological data, stack flow data, and emissions estimates based on radionuclide inventory data or continuous-monitoring systems data were the specific input to CAP88-PC for each modeled source.
Date: June 14, 1999
Creator: Berger, R. L.; Bertoldo, N. A.; Biermann, A. H.; Gallegos, G.; Hall, L. C.; Harrach, R. J. et al.
Partner: UNT Libraries Government Documents Department

2004 Environmental Report

Description: The Lawrence Livermore National Laboratory (LLNL) annual Environmental Report, prepared for the Department of Energy (DOE) and made available to the public, presents summary environmental data that characterizes site environmental management performance, summarizes environmental occurrences and responses reported during the calendar year, confirms compliance with environmental standards and requirements, and highlights significant programs and efforts. By explaining the results of effluent and environmental monitoring, mentioning environmental performance indicators and performance measure programs, and assessing the impact of Laboratory operations on the environment and the public, the report also demonstrates LLNL's continuing commitment to minimize any potentially adverse impact of its operations. The combination of environmental and effluent monitoring, source characterization, and dose assessment showed that radiological doses to the public caused by LLNL operations in 2004 were less than 0.26% of regulatory standards and more than 11,000 times smaller than dose from natural background. Analytical results and evaluations generally showed continuing low levels of most contaminants; remediation efforts further reduced the concentrations of contaminants of concern in groundwater and soil vapor. In addition, LLNL's extensive environmental compliance activities related to water, air, endangered species, waste, wastewater, and waste reduction controlled or reduced LLNL's effects on the environment. LLNL's environmental program clearly demonstrates a commitment to protecting the environment from operational impacts.
Date: September 28, 2005
Creator: Althouse, P E; Bertoldo, N A; Brown, R A; Campbell, C B; Clark, L M; Gallegos, G M et al.
Partner: UNT Libraries Government Documents Department

Environmental Monitoring Plan

Description: Environmental monitoring personnel from Lawrence Livermore National Laboratory (LLNL) prepared this ''Environmental Monitoring Plan'' (EMP) to meet the requirements in the U.S. Department of Energy (DOE) ''Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance'' (DOE 1991) and applicable portions of DOE Orders 5400.1 and 5400.5 (see WSS B93 and B94 in Appendix B). ''Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance'' is followed as a best management practice; under Work Smart Standards, LLNL complies with portions of DOE Orders 5400.1 and 5400.5 as shown in Appendix B. This document is a revision of the May 1999 EMP (Tate et al. 1999) and is current as of March 1, 2002. LLNL is one of the nation's premier applied-science national security laboratories. Its primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable, and to prevent the spread and use of nuclear weapons worldwide. LLNL's programs in advanced technologies, energy, environment, biosciences, and basic science apply LLNL's unique capabilities and enhance the competencies needed for this national security mission. LLNL's mission also involves working with industrial and academic partners to increase national competitiveness and improve science education. LLNL's mission is dynamic and has changed over the years to meet new national needs. In keeping with the Laboratory's mission, the environment, safety, and health (ES&H) have top priority. LLNL's policy is to perform work in a manner that protects the health and safety of employees and the public, preserves the quality of the environment, and prevents property damage. The environment, safety, and health are to be priority considerations in the planning and execution of all work activities at the Laboratory (LLNL 2001). Furthermore, it is the policy of LLNL to comply with applicable ES&H laws, regulations, and requirements. Under Contract 48, Appendix F, the ...
Date: January 10, 2006
Creator: Althouse, P E; Biermann, A; Brigdon, S L; Brown, R A; Campbell, C G; Christofferson, E et al.
Partner: UNT Libraries Government Documents Department