3,082 Matching Results

Results open in a new window/tab.

1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS. (open access)

1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS.

A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) proton Accelerator is being studied as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The major benefit is that it would considerably shorten the overall AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power at the top energy of 28 GeV. This paper describes the FFAG design for acceleration of protons from 400 MeV to 1.5 GeV, with the same circumference of the AGS, and entirely housed in the AGS tunnel.
Date: July 5, 2004
Creator: Ruggiero, A. G.; Blaskiewicz, M.; Trbojevic, D.; Tsoupas, N. & Zhang, W.
System: The UNT Digital Library
A 1-Joule laser for a 16-fiber injection system (open access)

A 1-Joule laser for a 16-fiber injection system

A 1-J laser was designed to launch light down 16, multi-mode fibers (400-{micro}m-core dia.). A diffractive-optic splitter was designed in collaboration with Digital Optics Corporation (DOC), and was delivered by DOC. Using this splitter, the energy injected into each fiber varied <1%. The spatial profile out of each fiber was such that there were no ''hot spots,'' a flyer could successfully be launched and a PETN pellet could be initiated. Preliminary designs of the system were driven by system efficiency where a pristine TEM{sub 00} laser beam would be required. The laser is a master oscillator, power amplifier (MOPA) consisting of a 4-mm-dia. Nd:YLF rod in the stable, q-switched oscillator and a 9.5-mm-dia. Nd:YLF rod in the double-passed amplifier. Using a TEM{sub 00} oscillator beam resulted in excellent transmission efficiencies through the fibers at lower energies but proved to be quite unreliable at higher energies, causing premature fiber damage, flyer plate rupture, stimulated Raman scattering (SRS), and stimulated Brillouin scattering (SBS). Upon further investigation, it was found that both temporal and spatial beam formatting of the laser were required to successfully initiate the PETN. Results from the single-mode experiments, including fiber damage, SRS and SBS losses, will be presented. In …
Date: April 6, 2004
Creator: Honig, J.
System: The UNT Digital Library
2-MV electrostatic quadrupole injector for heavy-ion fusion (open access)

2-MV electrostatic quadrupole injector for heavy-ion fusion

High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole (ESQ) injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV Injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment (HCX) and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.
Date: November 10, 2004
Creator: Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L. & Seidl, P. A.
System: The UNT Digital Library
3-D Combinatorial Geometry in the MERCURY Monte Carlo Particle Transport Code (open access)

3-D Combinatorial Geometry in the MERCURY Monte Carlo Particle Transport Code

Lawrence Livermore National Laboratory is in the process of developing a new Monte Carlo Particle Transport code named MERCURY. This new code features a 3-D Combinatorial Geometry tracking algorithm. This paper details some of the characteristics of this Monte Carlo tracker
Date: September 27, 2004
Creator: Greenman, G
System: The UNT Digital Library
3-D Thermal Evaluations for a Fueled Experiment in the Advanced Test Reactor (open access)

3-D Thermal Evaluations for a Fueled Experiment in the Advanced Test Reactor

The DOE Advanced Fuel Cycle Initiative and Generation IV reactor programs are developing new fuel types for use in the current Light Water Reactors and future advanced reactor concepts. The Advanced Gas Reactor program is planning to test fuel to be used in the Next Generation Nuclear Plant (NGNP) nuclear reactor. Preliminary information for assessing performance of the fuel will be obtained from irradiations performed in the Advanced Test Reactor large ''B'' experimental facility. A test configuration has been identified for demonstrating fuel types typical of gas cooled reactors or fast reactors that may play a role in closing the fuel cycle or increasing efficiency via high temperature operation Plans are to have 6 capsules, each containing 12 compacts, for the test configuration. Each capsule will have its own temperature control system. Passing a helium-neon gas through the void regions between the fuel compacts and the graphite carrier and between the graphite carrier and the capsule wall will control temperature. This design with three compacts per axial level was evaluated for thermal performance to ascertain the temperature distributions in the capsule and test specimens with heating rates that encompass the range of initial heat generation rates.
Date: October 6, 2004
Creator: Ambrosek, Richard G.; Chang, Gray S. & Utterbeck, Debby J.
System: The UNT Digital Library
3-D Thermal Evaluations for a Fueled Experiment in the Advanced Test Reactor (open access)

3-D Thermal Evaluations for a Fueled Experiment in the Advanced Test Reactor

The DOE Advanced Fuel Cycle Initiative and Generation IV reactor programs are developing new fuel types for use in the current Light Water Reactors and future advanced reactor concepts. The Advanced Gas Reactor program is planning to test fuel to be used in the Next Generation Nuclear Plant (NGNP) nuclear reactor. Preliminary information for assessing performance of the fuel will be obtained from irradiations performed in the Advanced Test Reactor large “B” experimental facility. A test configurations has been identified for demonstrating fuel types typical of gas cooled reactors or fast reactors that may play a role in closing the fuel cycle or increasing efficiency via high temperature operation Plans are to have 6 capsules, each containing 12 compacts, for the test configuration. Each capsule will have its own temperature control system. Passing a helium-neon gas through the void regions between the fuel compacts and the graphite carrier and between the graphite carrier and the capsule wall will control temperature. This design with three compacts per axial level was evaluated for thermal performance to ascertain the temperature distributions in the capsule and test specimens with heating rates that encompass the range of initial heat generation rates.
Date: October 1, 2004
Creator: Ambrosek, Richard; Chang, Gray & Utterbeck, Debra
System: The UNT Digital Library
A 10 Hz Grazing Incidence pumped Ni-like Mo laser at 18.9 nm with 150 mJ pump energy (open access)

A 10 Hz Grazing Incidence pumped Ni-like Mo laser at 18.9 nm with 150 mJ pump energy

The first demonstration of the grazing incidence pumping (GRIP) scheme for laser-driven x-ray lasers (XRLs) is described utilizing 2-pulse pumping. A long pulse is incident normal to the target to produce a plasma with a particular density profile. Then a short pulse is incident at a grazing angle, chosen to optimally couple the short pulse laser energy into the specific density region where the inversion process will occur. The short pulse is simultaneously absorbed and refracted at a maximum electron density specified by the chosen pump angle then turns back into the gain region. The increased path length gives improved absorption allowing a reduction in the drive energy required for lasing. A Ni-like Mo XRL at 18.9 nm has been demonstrated with only 150 mJ total pump energy and a repetition rate of 10 Hz. We report high gains of 60 cm{sup -1} and the achievement of gain saturation for targets of 4 mm length.
Date: September 30, 2004
Creator: Keenan, R.; Dunn, J.; Patel, P. K.; Price, D. F.; Smith, R. F. & Shlyaptsev, V. N.
System: The UNT Digital Library
A 10 kHz Short-Stroke Rotary Fast Tool Servo (open access)

A 10 kHz Short-Stroke Rotary Fast Tool Servo

None
Date: August 30, 2004
Creator: Montesanti, R C & Trumper, D L
System: The UNT Digital Library
A 16 Mev/Nucleon Cocktail for Heavy Ion Testing (open access)

A 16 Mev/Nucleon Cocktail for Heavy Ion Testing

This report gives the description of a new cocktail of heavy ions ranging from Z=7-36 at 16 MeV/Nucleon.
Date: July 31, 2004
Creator: McMahan, M. A.; Leitner, D.; Gimpel, T.; Morel, J.; Ninemire, B.; Siero, R. et al.
System: The UNT Digital Library
13th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Summary Discussion, 10-13 August 2003, Vail, Colorado (open access)

13th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Summary Discussion, 10-13 August 2003, Vail, Colorado

The 13th Workshop discussion sessions addressed recent progress, critical issues in implementing new technologies, and the role of fundamental R&D in the growing PV industry. For the first time, we included a rump session, which was held on Sunday evening, August 10. This session included a panel of representatives, from various photovoltaic companies, who led a discussion of''R&D Challenges in Si PV.'' A special poster/presentation session was held on Monday evening, August 11, in which NREL/DOE subcontractors highlighted their results of research performed during the current subcontract period. This session served as a subcontract review. The workshop offered special sessions to discuss: (1) High-Efficiency Si Solar Cells, which reviewed progress made in implementing high-efficiency Si solar cell fabrication processes in the manufacturing environment; (2) Advanced Processing, as future potential approaches for making Si solar cells; (3) Commercial Issues, which addressed basic understanding behind recent processes that have been used by the PV industry; and (4) Automation and Equipment, to address capabilities and requirements of new manufacturing equipment.
Date: January 1, 2004
Creator: Sopori, B.; Sinton, R.; Tan, T. & Swanson, D.
System: The UNT Digital Library
1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS. (open access)

1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.

This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with …
Date: March 10, 2004
Creator: LAMBIASE,R. ENG,W. SANDBERG,J. DEWAN,S. HOLMES,R. RUST,K. ZENG,J.
System: The UNT Digital Library
14th Workshop on Crystalline Silicon Solar Cells& Modules: Materials and Processes; Summary of Discussion Sessions (open access)

14th Workshop on Crystalline Silicon Solar Cells& Modules: Materials and Processes; Summary of Discussion Sessions

The 14th Workshop discussion sessions addressed funding needs for Si research and for R&D to enhance U.S. PV manufacturing. The wrap-up session specifically addressed topics for the new university silicon program. The theme of the workshop, Crystalline Silicon Solar Cells: Leapfrogging the Barriers, was selected to reflect the astounding progress in Si PV technology during last three decades, despite a host of barriers and bottlenecks. A combination of oral, poster, and discussion sessions addressed recent advances in crystal growth technology, new cell structures and doping methods, silicon feedstock issues, hydrogen passivation and fire through metallization, and module issues/reliability. The following oral/discussion sessions were conducted: (1) Technology Update; (2) Defects and Impurities in Si/Discussion; (3) Rump Session; (4) Module Issues and Reliability/Discussion; (5) Silicon Feedstock/Discussion; (6) Novel Doping, Cells, and Hetero-Structure Designs/Discussion; (7) Metallization/Silicon Nitride Processing/Discussion; (8) Hydrogen Passivation/Discussion; (9) Characterization/Discussion; and (10) Wrap-Up. This year's workshop lasted three and a half days and, for the first time, included a session on Si modules. A rump session was held on the evening of August 8, which addressed efficiency expectations and challenges of c Si solar cells/modules. Richard King of DOE and Daren Dance of Wright Williams& Kelly (formerly of Sematech) spoke …
Date: October 1, 2004
Creator: Sopori, B.; Tan, T.; Sinton, R. & Swanson, D.
System: The UNT Digital Library
16th ANS Topical Meeting on the Technology of Fusion Energy (open access)

16th ANS Topical Meeting on the Technology of Fusion Energy

None
Date: January 1, 2004
Creator: Kulcinski, Gerald
System: The UNT Digital Library
17th Annual ALS Users' Association Meeting (open access)

17th Annual ALS Users' Association Meeting

It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, ALS staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the ALS patio.
Date: November 29, 2004
Creator: Robinson, Art & Tamura, Lori
System: The UNT Digital Library
The 1997/98 El Nino: A Test for Climate Models (open access)

The 1997/98 El Nino: A Test for Climate Models

Version 3 of the Hadley Centre Atmospheric Model (HadAM3) has been used to demonstrate one means of comparing a general circulation model with observations for a specific climate perturbation, namely the strong 1997/98 El Nino. This event was characterized by the collapse of the tropical Pacific's Walker circulation, caused by the lack of a zonal sea surface temperature gradient during the El Nino. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. HadAM3 likewise produced the observed collapse of the Walker circulation, and it did a reasonable job of reproducing the west/east cloud structure changes. This illustrates that the 1997/98 El Nino serves as a useful means of testing cloud-climate interactions in climate models.
Date: March 5, 2004
Creator: Lu, R; Dong, B; Cess, R D & Potter, G L
System: The UNT Digital Library
2003 Archaea: Ecology, Metabolism and Molecular Biology (open access)

2003 Archaea: Ecology, Metabolism and Molecular Biology

The Gordon Research Conference (GRC) on 2003 Archaea: Ecology, Metabolism and Molecular Biology was held at Proctor Academy, Andover, NH from August 3-8, 2003. The Conference was well-attended with 150 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field. I want to personally thank you for your support of this Conference. As you know, in the interest of promoting the presentation of unpublished and frontier-breaking research, Gordon Research …
Date: September 21, 2004
Creator: Shand, Richard F.
System: The UNT Digital Library
2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003 (open access)

2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003

The Gordon Research Conference (GRC) on 2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003 was held at Bates College, Lewiston, Maine, July 6-11, 2003. The Conference was well-attended with 103 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.
Date: September 10, 2004
Creator: Bernstein, Elliot
System: The UNT Digital Library
2003 Laser Diagnostic in Combustion Conference (open access)

2003 Laser Diagnostic in Combustion Conference

The GRC Laser Diagnostics in Combustion aims at bringing together scientists and engineers working in the front edge of research and development to discuss and find new ways to solve problems connected to combustion diagnostics. Laser-based techniques have proven to be very efficient tools for studying combustion processes thanks to features as non-intrusiveness in combination with high spatial and temporal resolution. Major tasks for the community are to develop and apply techniques for quantitative measurements with high precision e.g of species concentrations, temperatures, velocities and particles characteristics (size and concentration). These issues are of global interest, considering that the major part of the World's energy conversion comes from combustion sources and the influence combustion processes have on the environment and society.
Date: September 10, 2004
Creator: Allen, Mark G.
System: The UNT Digital Library
2003 Organometallic Chemistry Gordon Conference to be held July 20-25, 2003 (open access)

2003 Organometallic Chemistry Gordon Conference to be held July 20-25, 2003

None
Date: September 10, 2004
Creator: Bullock, R. Morris
System: The UNT Digital Library
2003 Partial Support of the Photoions:Photoionization and Photodetachment Gordon Research Conference (open access)

2003 Partial Support of the Photoions:Photoionization and Photodetachment Gordon Research Conference

The Gordon Research Conference (GRC) on 2004 Gordon Research Conference on Biopolymers was held at Queen's College, Oxford, United Kingdom on 9/21-26/2003. The Conference was well-attended with 57 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field. I want to personally thank you for your support of this Conference. As you know, in the interest of promoting the presentation of unpublished and frontier-breaking research, Gordon Research Conferences does …
Date: November 1, 2004
Creator: Eland, John HD
System: The UNT Digital Library
2003 Plant Cell Walls Gordon Conference (open access)

2003 Plant Cell Walls Gordon Conference

This conference will address recent progress in many aspects of cell wall biology. Molecular, genetic, and genomic approaches are yielding major advances in our understanding of the composition, synthesis, and architecture of plant cell walls and their dynamics during growth, and are identifying the genes that encode the machinery needed to make their biogenesis possible. This meeting will bring together international scientists from academia, industry and government labs to share the latest breakthroughs and perspectives on polysaccharide biosynthesis, wood formation, wall modification, expansion and interaction with other organisms, and genomic & evolutionary analyses of wall-related genes, as well as to discuss recent ''nanotechnological'' advances that take wall analysis to the level of a single cell.
Date: September 21, 2004
Creator: Cosgrove, Daniel J.
System: The UNT Digital Library
2004 Annual Meeting - Genes, Mutations and Disease: The Environmental Connection (open access)

2004 Annual Meeting - Genes, Mutations and Disease: The Environmental Connection

The Meeting consisted of 9 Symposia, 4 Keynote Lectures, 3 Platform Sessions and 4 Poster Sessions. In addition there were Breakfast Meetings for Special Interest Groups designed to inform attendees about the latest advances in environmental mutagenesis research. Several of the topics to be covered at this broad meeting will be of interest to the Department of Energy, Office of Science. The relevance of this meeting to the DOE derives from the fact that low dose radiation may represent one of the most significant sources of human mutations that are attributable to the environment. The EMS membership, and those who attended the EMS Annual Meeting were interested in both chemical and radiation induced biological effects, such as cell death, mutation, teratogenesis, carcinogenesis and aging. These topics thate were presented at the 2004 EMS Annual meeting that were of clear interest to DOE include: human variation in cancer susceptibility, unusual mechanisms of mutation, germ and stem cell mutagenesis, recombination and the maintenance of genomic stability, multiple roles for DNA mismatch repair, DNA helicases, mutation, cancer and aging, Genome-wide transcriptional responses to environmental change, Telomeres and genomic stability: when ends don?t meet, systems biology approach to cell phenotypic decision processes, and the …
Date: August 23, 2004
Creator: Samson, Leona D.
System: The UNT Digital Library
2004 Atomic and Molecular Interactions Gordon Research Conference (open access)

2004 Atomic and Molecular Interactions Gordon Research Conference

The 2004 Gordon Research Conference on Atomic and Molecular Interactions was held July 11-16 at Colby-Sawyer College, New London, New Hampshire. This latest edition in a long-standing conference series featured invited talks and contributed poster papers on dynamics and intermolecular interactions in a variety of environments, ranging from the gas phase through surfaces and condensed media. A total of 90 conferees participated in the conference.
Date: October 25, 2004
Creator: Dagdigian, Dr. Paul J.
System: The UNT Digital Library
2004 Molecular and Ionic Clusters Gordon Conference - September 5-10, 2004 (open access)

2004 Molecular and Ionic Clusters Gordon Conference - September 5-10, 2004

This Report is Gordon Conference Molecular and Ionic Clusters Final Report and Agenda.
Date: September 5, 2004
Creator: Zwier, Timoty S.
System: The UNT Digital Library