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A Flight Simulator for ATF2 - A Mechanism for International Collaboration in the Writing and Deployment of Online Beam Dynamics Algorithms
The goals of ATF2 are to test a novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from an extracted beam from the ATF ring of {approx}30nm vertical normalized emittance, and to stabilize it at the IP-waist to the {approx}2nm level. Static and dynamic tolerances on all accelerator components are very tight; the achievement of the ATF2 goals is reliant on the application of multiple high-level beam dynamics control algorithms to align and tune the electron beam in the extraction line and final focus system. Much algorithmic development work has been done in Japan and by colleagues in collaborating nations in North America and Europe. We describe here development work towards realizing a 'flight simulator' environment for the shared development and implementation of beam dynamics code. This software exists as a 'middle-layer' between the lower-level control systems (EPICS and V-SYSTEM) and the multiple higher-level beam dynamics modeling tools in use by the three regions (SAD, Lucretia, PLACET, MAD...).
Date:
July 25, 2008
Creator:
White, Glen; Molloy, Stephen; Seryi, Andrei; Schulte, Daniel; Tomas, Rogelio; Kuroda, Shigeru et al.
Object Type:
Article
System:
The UNT Digital Library
SUPERCONDUCTING MAGNET NEEDS FOR THE ILC.
The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the lLC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.
Date:
June 25, 2007
Creator:
PARKER, B.; TOMPKINS, J. C.; KASHIKHIN, V. I.; PALMER, M. A. & CLARKE, J. A.
Object Type:
Article
System:
The UNT Digital Library
Billion particle linac simulations for future light sources
In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.
Date:
September 25, 2008
Creator:
Ryne, R. D.; Venturini, M.; Zholents, A. A. & Qiang, J.
Object Type:
Article
System:
The UNT Digital Library
Final Report for "Simulation Tools for Parallel Microwave Particle in Cell Modeling"
Transport of high-power rf fields and the subsequent deposition of rf power into plasma is an important component of developing tokamak fusion energy. Two limitations on rf heating are: (i) breakdown of the metallic structures used to deliver rf power to the plasma, and (ii) a detailed understanding of how rf power couples into a plasma. Computer simulation is a main tool for helping solve both of these problems, but one of the premier tools, VORPAL, is traditionally too difficult to use for non-experts. During this Phase II project, we developed the VorpalView user interface tool. This tool allows Department of Energy researchers a fully graphical interface for analyzing VORPAL output to more easily model rf power delivery and deposition in plasmas.
Date:
September 25, 2008
Creator:
Stoltz, Peter H
Object Type:
Report
System:
The UNT Digital Library
Gluon scattering in N=4 super-Yang-Mills theory fromweak to strong coupling
I describe some recent developments in the understanding of gluon scattering amplitudes in N = 4 super-Yang-Mills theory in the large-N{sub c} limit. These amplitudes can be computed to high orders in the weak coupling expansion, and also now at strong coupling using the AdS/CFT correspondence. They hold the promise of being solvable to all orders in the gauge coupling, with the help of techniques based on integrability. They are intimately related to expectation values for polygonal Wilson loops composed of light-like segments.
Date:
March 25, 2008
Creator:
Dixon, Lance J.
Object Type:
Article
System:
The UNT Digital Library
High resolution 17 keV to 75 keV backlighters for High Energy Density experiments
We have developed 17 keV to 75 keV 1-dimensional and 2-dimensional high-resolution (< 10 {micro}m) radiography using high-intensity short pulse lasers. High energy K-{alpha} sources are created by fluorescence from hot electrons interacting in the target material after irradiation by lasers with intensity I{sub L} > 10{sup 17} W/cm{sup 2}. We have achieved high resolution point projection 1-dimensional and 2-dimensional radiography using micro-foil and micro-wire targets attached to low-Z substrate materials. The micro-wire size was 10 {micro}m x 10 {micro}m x 300 {micro}m on a 300 {micro}m x 300 {micro}m x 5 {micro}m CH substrate. The radiography performance was demonstrated using the Titan laser at LLNL. We observed that the resolution is dominated by the micro-wire target size and there is very little degradation from the plasma plume, implying that the high energy x-ray photons are generated mostly within the micro-wire volume. We also observe that there are enough K{alpha} photons created with a 300 J, 1-{omega}, 40 ps pulse laser from these small volume targets, and that the signal-to-noise ratio is sufficiently high, for single shot radiography experiments. This unique technique will be used on future high energy density (HED) experiments at the new Omega-EP, ZR and NIF facilities.
Date:
February 25, 2008
Creator:
Park, H.; Maddox, B. R.; Giraldez, E.; Hatchett, S. P.; Hudson, L.; Izumi, N. et al.
Object Type:
Article
System:
The UNT Digital Library
On-site Analysis of Explosives in Various Matrices
Lawrence Livermore National Laboratory (LLNL) has developed several different strategies and technologies for the on-site detection of explosives. These on-site detection techniques include a colorimetric test, thin layer chromatography (TLC) kit and portable gas chromatography mass spectrometer (GC/MS). The screening of suspicious containers on-site and the search for trace explosive residue in a post-blast forensic investigation are of great importance. For these reasons, LLNL's Forensic Science Center has developed a variety of fieldable detection technologies to screen for a wide range of explosives in various matrices and scenarios. Ideally, what is needed is a fast, accurate, easy-to-use, pocket-size and inexpensive field screening test for explosives.
Date:
January 25, 2006
Creator:
Reynolds, J. G.; Nunes, P.; Whipple, R. E. & Alcaraz, A.
Object Type:
Article
System:
The UNT Digital Library
The energy coupling efficiency of multi-wavelength laser pulses to damage initiating defects in DKDP nonlinear crystals
The bulk damage performance of potassium dihydrogen phosphate crystals under simultaneous exposure to 1064-, 532-, and 355-nm nanosecond-laser pulses is investigated in order to probe the laser-induced defect reactions leading to damage initiation during frequency conversion. The results provide insight into the mechanisms governing the behavior of the damage initiating defects under exposure to high power laser light. In addition, it is suggested that the damage performance can be directly related to and predicted from the damage behavior of the crystal at each wavelength separately.
Date:
September 25, 2007
Creator:
DeMange, P; Negres, R A; Rubenchik, A M; Radousky, H B; Feit, M D & Demos, S G
Object Type:
Article
System:
The UNT Digital Library
Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons
An optical injection scheme for a laser-plasma basedaccelerator which employs a non-collinear counter-propagating laser beamto push background electrons in the focusing and acceleration phase viaponderomotive beat with the trailing part of the wakefield driver pulseis discussed. Preliminary experiments were performed using a drive beamof a_0 = 2.6 and colliding beam of a_1 = 0.8 both focused on the middleof a 200 mu m slit jet backed with 20 bar, which provided ~; 260 mu mlong gas plume. The enhancement in the total charge by the collidingpulse was observed with sharp dependence on the delay time of thecolliding beam. Enhancement of the neutron yield was also measured, whichsuggests a generation of electrons above 10 MeV.
Date:
June 25, 2007
Creator:
Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans,Wim P.; Nakamura, Kei; Panasenko, Dmitriy et al.
Object Type:
Article
System:
The UNT Digital Library
Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on …
Date:
April 25, 2007
Creator:
McCoy, M; Kusnezov, D; Bikkel, T & Hopson, J
Object Type:
Report
System:
The UNT Digital Library
Remaining Sites Verification Package for the 100-F-33, 146-F Aquatic Biology Fish Ponds, Waste Site Reclassification Form 2006-021
The 100-F-33, 146-F Aquatice Biology Fish Ponds waste site was an area with six small rectangular ponds and one large circular pond used to conduct tests on fish using various mixtures of river and reactor effluent water. The current site conditions achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification and applicable confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date:
August 25, 2006
Creator:
Dittmer, L. M.
Object Type:
Report
System:
The UNT Digital Library
THE SUPERCONDUCTION MAGNETS OF THE ILC BEAM DELIVERY SYSTEM.
The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.
Date:
June 25, 2007
Creator:
PARKER,B.; ANEREELA, M.; ESCALLIE, J.; HE, P.; JAIN, A.; MARONE, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Surveillance of site A and plot M, report for 2007.
The results of the environmental surveillance program conducted at Site A/Plot M in the Palos Forest Preserve area for Calendar Year 2007 are presented. Based on the results of the 1976-1978 radiological characterization of the site, a determination was made that a surveillance program be established. The characterization study determined that very low levels of hydrogen-3 (as tritiated water) had migrated from the burial ground and were present in two nearby hand pumped picnic wells. The current surveillance program began in 1980 and consists of sample collection and analysis of surface and subsurface water. The results of the analyses are used to: (1) monitor the migration pathway of water from the burial ground (Plot M) to the hand-pumped picnic wells, (2) establish if other buried radionuclides have migrated, and (3) monitor the presence of radioactive materials in the environment of the area. Hydrogen-3 in the Red Gate Woods picnic wells was still detected this year, but the average and maximum concentrations were significantly less than found earlier. Hydrogen-3 continues to be detected in a number of wells, boreholes, dolomite holes, and a surface stream. Analyses since 1984 have indicated the presence of low levels of strontium-90 in water from a …
Date:
March 25, 2008
Creator:
Golchert, N. W. & Oversight, ESH /QA
Object Type:
Report
System:
The UNT Digital Library
Discovery of Radio Emission From Transient Anomalous X-Ray Pulsar XTE J1810-197
We report the first detection of radio emission from any anomalous X-ray pulsar (AXP). Data from the Very Large Array (VLA) MAGPIS survey with angular resolution 6'' reveals a point-source of flux density 4.5 {+-} 0.5 mJy at 1.4 GHz at the precise location of the 5.54 s pulsar XTE J1810-197. This is greater than upper limits from all other AXPs and from quiescent states of soft gamma-ray repeaters (SGRs). The detection was made in 2004 January, 1 year after the discovery of XTE J1810-197 during its only known outburst. Additional VLA observations both before and after the outburst yield only upper limits that are comparable to or larger than the single detection, neither supporting nor ruling out a decaying radio afterglow related to the X-ray turn-on. Another hypothesis is that, unlike the other AXPs and SGRs, XTE J1810-197 may power a radio synchrotron nebula by the interaction of its particle wind with a moderately dense environment that was not evacuated by previous activity from this least luminous, in X-rays, of the known magnetars.
Date:
October 25, 2005
Creator:
Halpern, J P; Gotthelf, E V; Becker, R H; Helfand, D J & White, R L
Object Type:
Article
System:
The UNT Digital Library
Workshop on ENU Mutagenesis: Planning for Saturation, July 25-28, 2002
The goal of the conference is to enhance the development of improved technologies and new approaches to the identification of genes underlying chemically-induced mutant phenotypes. The conference brings together ENU mutagenesis experts from the United States and aborad for a small, intensive workshop to consider these issues.
Date:
July 25, 2002
Creator:
Nadeau, Joseph H
Object Type:
Article
System:
The UNT Digital Library
Initial Report on the Development of a Monte Carlo-Markov Chain Joint Inversion Approach for Geothermal Exploration
Geothermal exploration and subsequent characterization of potential resources typically employ a variety of geophysical, geologic and geochemical techniques. However, since the data collected by each technique provide information directly on only one or a very limited set of the many physical parameters that characterize a geothermal system, no single method can be used to describe the system in its entirety. Presently, the usual approach to analyzing disparate data streams for geothermal applications is to invert (or forward model) each data set separately and then combine or compare the resulting models, for the most part in a more or less ad hoc manner. However, while each inversion may yield a model that fits the individual data set, the models are usually inconsistent with each other to some degree. This reflects uncertainties arising from the inevitable fact that geophysical and other exploration data in general are to some extent noisy, incomplete, and of limited sensitivity and resolution, and so yield non-unique results. The purpose of the project described here is to integrate the different model constraints provided by disparate geophysical, geological and geochemical data in a rigorous and consistent manner by formal joint inversion. The objective is to improve the fidelity of …
Date:
April 25, 2007
Creator:
Foxall, W; Ramirez, A; Carlson, S; Dyer, K & Sun, Y
Object Type:
Report
System:
The UNT Digital Library
Waste Isolation Pilot Plant Biennial Environmental Compliance Report
This Biennial Environmental Compliance Report (BECR) documents environmental regulatory compliance at the Waste Isolation Pilot Plant (WIPP), a facility designed and authorized for the safe disposal of transuranic (TRU) radioactive waste, for the reporting period of April 1, 2002, to March 31, 2004. As required by the WIPP Land Withdrawal Act (LWA) (Public Law [Pub. L.] 102-579, as amended by Pub. L. 104-201), the BECR documents U.S. Department of Energy (DOE) compliance with applicable environmental protection laws and regulations implemented by agencies of the federal government and the state of New Mexico.
Date:
October 25, 2004
Creator:
Washington Regulatory and Environmental Services
Object Type:
Report
System:
The UNT Digital Library
Simulations of carbon fiber composite delamination tests
Simulations of mode I interlaminar fracture toughness tests of a carbon-reinforced composite material (BMS 8-212) were conducted with LSDYNA. The fracture toughness tests were performed by U.C. Berkeley. The simulations were performed to investigate the validity and practicality of employing decohesive elements to represent interlaminar bond failures that are prevalent in carbon-fiber composite structure penetration events. The simulations employed a decohesive element formulation that was verified on a simple two element model before being employed to perform the full model simulations. Care was required during the simulations to ensure that the explicit time integration of LSDYNA duplicate the near steady-state testing conditions. In general, this study validated the use of employing decohesive elements to represent the interlaminar bond failures seen in carbon-fiber composite structures, but the practicality of employing the elements to represent the bond failures seen in carbon-fiber composite structures during penetration events was not established.
Date:
October 25, 2007
Creator:
Kay, G
Object Type:
Report
System:
The UNT Digital Library
BENCH-SCALE STEAM REFORMING OF ACTUAL TANK 48H WASTE
Fluidized Bed Steam Reforming (FBSR) has been demonstrated to be a viable technology to remove >99% of the organics from Tank 48H simulant, to remove >99% of the nitrate/nitrite from Tank 48H simulant, and to form a solid product that is primarily carbonate based. The technology was demonstrated in October of 2006 in the Engineering Scale Test Demonstration Fluidized Bed Steam Reformer1 (ESTD FBSR) at the Hazen Research Inc. (HRI) facility in Golden, CO. The purpose of the Bench-scale Steam Reformer (BSR) testing was to demonstrate that the same reactions occur and the same product is formed when steam reforming actual radioactive Tank 48H waste. The approach used in the current study was to test the BSR with the same Tank 48H simulant and same Erwin coal as was used at the ESTD FBSR under the same operating conditions. This comparison would allow verification that the same chemical reactions occur in both the BSR and ESTD FBSR. Then, actual radioactive Tank 48H material would be steam reformed in the BSR to verify that the actual tank 48H sample reacts the same way chemically as the simulant Tank 48H material. The conclusions from the BSR study and comparison to the ESTD …
Date:
September 25, 2008
Creator:
Burket, P; Gene Daniel, G; Charles Nash, C; Carol Jantzen, C & Michael Williams, M
Object Type:
Report
System:
The UNT Digital Library
RECENT ACTIVITIES OF THE NUCLEAR SMUGGLING INTERNATIONAL TECHNICAL WORKING GROUP TO THWART ILLICIT TRAFFICKING
The Nuclear Smuggling International Technical Working Group (ITWG) is an informal association of nuclear forensic practitioners working in partnership with law enforcement, first responder, and nuclear regulatory professionals that cooperate to deter the illicit trafficking of nuclear materials. The objective of the ITWG is to advance the science of nuclear forensics and to provide a common approach and effective technical solutions to governments who request assistance. the ITWG was chartered in 1996 and since that time 30 nations and organizations have participated in 12 annual meetings and two analytical round-robin trials involving plutonium and highly enriched uranium. A third analytical round-robin as well as several table-top exercises are planned for later in 2007-2008. International interest in the ITWG has grown in over the past five years measured by the number of participants at its annual meetings. This growth has spawned the ITWG Nuclear Forensics Laboratories as a companion technical affiliate focusing exclusively on the scientific aspects of nuclear forensics and nuclear smuggling incident response.
Date:
October 25, 2007
Creator:
Smith, D K; Biro, T; Chartier, B; Mayer, K; Niemeyer, S & Thompson, P
Object Type:
Report
System:
The UNT Digital Library
A simple and realistic model of supersymmetry breaking
We present a simple and realistic model of supersymmetry breaking. In addition to the minimal supersymmetric standard model, we only introduce a hidden sector gauge group SU(5) and three fields X, F and \bar{F}. Supersymmetry is broken at a local minimum of the potential, and its effects are transmitted to the supersymmetric standard model sector through both standard model gauge loops and local operators suppressed by the cutoff scale, which is taken to be the unification scale. The form of the local operators is controlled by a U(1) symmetry. The generated supersymmetry breaking and mu parameters are comparable in size, and no flavor or CP violating terms arise. The spectrum of the first two generation superparticles is that of minimal gauge mediation with the number of messengers N_mess = 5 and the messenger scale 1011 GeV< M_mess< 1013 GeV. The spectrum of the Higgs bosons and third generation superparticles, however, can deviate from it. The lightest supersymmetric particle is the gravitino with a mass of order (1-10) GeV.
Date:
September 25, 2007
Creator:
Nomura, Yasunori & Papucci, Michele
Object Type:
Article
System:
The UNT Digital Library
Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics
Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption.
Date:
July 25, 2008
Creator:
McMahan, Margaret A.; Blackmore, Ewart; Cascio, Ethan W.; Castaneda, Carlos; von Przewoski, Barbara & Eisen, Harvey
Object Type:
Article
System:
The UNT Digital Library
Advanced Accelerator Applications University Participation Program
Our research tasks span the range of technology areas for transmutation, gas-cooled reactor technology, and high temperature heat exchangers, including separation of actinides from spent nuclear fuel, methods of fuel fabrication, reactor-accelerator coupled experiments, corrosion of materials exposed to lead-bismuth eutectic, and special nuclear materials protection and accountability.
Date:
July 25, 2007
Creator:
Chen, Y. & Hechanova, A.
Object Type:
Report
System:
The UNT Digital Library
Hanford External Dosimetry Technical Basis Manual PNL-MA-842
The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has …
Date:
February 25, 2005
Creator:
Rathbone, Bruce A.
Object Type:
Report
System:
The UNT Digital Library