Resource Type

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR (open access)

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR

The objectives of the program during the past year was to complete Technical Objectives 2 and 3 and initiate Technical Objective 4 are described. To assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.
Date: April 1, 2005
Creator: Gee, Mark K.
System: The UNT Digital Library
2007 Microbial Population Biology (July 22-26, 2007) (open access)

2007 Microbial Population Biology (July 22-26, 2007)

Microbial Population Biology covers a diverse range of cutting edge issues in the microbial sciences and beyond. Firmly founded in evolutionary biology and with a strongly integrative approach, past meetings have covered topics ranging from the dynamics and genetics of adaptation to the evolution of mutation rate, community ecology, evolutionary genomics, altruism, and epidemiology. This meeting is never dull: some of the most significant and contentious issues in biology have been thrashed out here. We anticipate the 2007 meeting being no exception. The final form of the 2007 meeting is yet to be decided, but the following topics are likely to be included: evolutionary emergence of infectious disease and antibiotic resistance, genetic architecture and implications for the evolution of microbial populations, ageing in bacteria, biogeography, evolution of symbioses, the role of microbes in ecosystem function, and ecological genomics.
Date: April 1, 2008
Creator: Dean, Anthony M. & Gray, Nancy Ryan
System: The UNT Digital Library
A 3D Frictional Segment-to-Segment Contact Method for Large Deformations and Quadratic Elements (open access)

A 3D Frictional Segment-to-Segment Contact Method for Large Deformations and Quadratic Elements

Node-on-segment contact is the most common form of contact used today but has many deficiencies ranging from potential locking to non-smooth behavior with large sliding. Furthermore, node-on-segment approaches are not at all applicable to higher order discretizations (e.g. quadratic elements). In a previous work, [3, 4] we developed a segment-to-segment contact approach for eight node hexahedral elements based on the mortar method that was applicable to large deformation mechanics. The approach proved extremely robust since it eliminated the over-constraint that caused 'locking' and provided smooth force variations in large sliding. Here, we extend this previous approach to treat frictional contact problems. In addition, the method is extended to 3D quadratic tetrahedrals and hexahedrals. The proposed approach is then applied to several challenging frictional contact problems that demonstrate its effectiveness.
Date: April 1, 2004
Creator: Puso, M; Laursen, T & Solberg, J
System: The UNT Digital Library
6th Annual Systems Biology Symposium: Systems Biology and the Environment (open access)

6th Annual Systems Biology Symposium: Systems Biology and the Environment

Systems biology recognizes the complex multi-scale organization of biological systems, from molecules to ecosystems. The International Symposium on Systems Biology is an annual two-day event gathering the most influential researchers transforming biology into an integrative discipline investigating complex systems. In recognition of the fundamental similarity between the scientific problems addressed in environmental science and systems biology studies at the molecular, cellular, and organismal levels, the 2007 Symposium featured global leaders in “Systems Biology and the Environment.” The objective of the 2007 “Systems Biology and the Environment” International Symposium was to stimulate interdisciplinary thinking and research that spans systems biology and environmental science. This Symposium was well aligned with the DOE’s Genomics:GTL program efforts to achieve scientific objectives for each of the three DOE missions: • Develop biofuels as a major secure energy source for this century, • Develop biological solutions for intractable environmental problems, and • Understand biosystems’ climate impacts and assess sequestration strategies Our scientific program highlighted world-class research exemplifying these priorities. The Symposium featured 45 minute lectures from 12 researchers including: Penny/Sallie Chisholm of MIT gave the keynote address “Tiny Cells, Global Impact: What Prochlorococcus Can Teach Us About Systems Biology”, plus Jim Fredrickson of PNNL, Nitin Baliga …
Date: April 1, 2007
Creator: Galitski, Timothy, P.
System: The UNT Digital Library
7th Annual Systems Biology Symposium: Systems Biology and Engineering (open access)

7th Annual Systems Biology Symposium: Systems Biology and Engineering

Systems biology recognizes the complex multi-scale organization of biological systems, from molecules to ecosystems. The International Symposium on Systems Biology has been hosted by the Institute for Systems Biology in Seattle, Washington, since 2002. The annual two-day event gathers the most influential researchers transforming biology into an integrative discipline investingating complex systems. Engineering and application of new technology is a central element of systems biology. Genome-scale, or very small-scale, biological questions drive the enigneering of new technologies, which enable new modes of experimentation and computational analysis, leading to new biological insights and questions. Concepts and analytical methods in engineering are now finding direct applications in biology. Therefore, the 2008 Symposium, funded in partnership with the Department of Energy, featured global leaders in "Systems Biology and Engineering."
Date: April 1, 2008
Creator: Galitski, Timothy P.
System: The UNT Digital Library
Ab initio study of Al(III) adsorption on stepped {100} surfaces of KDP crystals (open access)

Ab initio study of Al(III) adsorption on stepped {100} surfaces of KDP crystals

Crystals of potassium dihydrogen phosphate (KH{sub 2}PO{sub 4}, KDP) are grown in large scale for use as nonlinear material in laser components. Traces of trivalent metal impurities are often added to the supernatant to achieve habit control during crystal growth, selectively inhibiting the growth of the {l_brace}100{r_brace} face. Model systems representing AlPO{sub 4}-doped KDP {l_brace}100{r_brace} stepped surfaces are prepared and studied using ab initio quantum methods. Results of Hartree-Fock partial optimizations are presented, including estimated energies of ion pair binding to the steps. We find that the PO{sub 4}{sup 3-} ion takes a position not unlike that of a standard phosphate in the crystal lattice, while the aluminum atom is displaced far from a K{sup +} ion position to establish coordinations with the PO{sub 4}{sup 3-} ion and to bind with another lattice-bound phosphate. Our optimized structures suggest that it is the formation of a fourth coordination of Al(III) to a third phosphate ion from solution, or perhaps from a nearby position in the lattice, that disrupts further deposition, pinning the steps.
Date: April 1, 2004
Creator: Salter, E A; Wierzbicki, A & Land, T A
System: The UNT Digital Library
About NICADD extruded scintillating strips (open access)

About NICADD extruded scintillating strips

The results of control measurements of extruded scintillating strip responses to a radioactive source Sr-90 are provided, and details of strip choice, preparation, and method of measurement are included. About four hundred one meter long extruded scintillating strips were measured at four different points. These results were essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.
Date: April 1, 2005
Creator: Dyshkant, A.; Beznosko, D.; Blazey, G.; Chakraborty, D.; Francis, K.; Kubik, D. et al.
System: The UNT Digital Library
Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization. (open access)

Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization.

Abstract: Increased forest productivity has been obtained by improving resource availability through water and nutrient amendments. However, more stress-tolerant species that have robust site requirements do not respond consistently to irrigation. An important factor contributing to robust site requirements may be the distribution of biomass belowground, yet available information is limited. We examined the accumulation and distribution of above- and below-ground biomass in sweetgum (Liqrridambar sfyrac$lua L.) and loblolly pine (Pinus taeda L.) stands receiving irrigation and fertilization. Mean annual aboveground production after 4 years ranged from 2.4 to 5.1 ~g.ha-'.year' for sweetgum and from 5.0 to 6.9 ~g.ha-l.year-l for pine. Sweetgum responded positively to irrigation and fertilization with an additive response to irrigation + fertilization. Pine only responded to fertilization. Sweetgum root mass fraction (RME)in creased with fertilization at 2 years and decreased with fertilization at 4 years. There were no detectable treatment differences in loblolly pine RMF. Development explained from 67% to 98% of variation in shoot versus root allometry for ephemeral and perennial tissues, fertilization explained no more than 5% of the variation in for either species, and irrigation did not explain any. We conclude that shifts in allocation from roots to shoots do not explain nutrient-induced …
Date: April 1, 2008
Creator: Coyle, David, R.; Coleman, Mark, D. & Aubrey, Doug, P.
System: The UNT Digital Library
Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest. (open access)

Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.
Date: April 1, 2005
Creator: Horn, Scott; Hanula, James, L.; Ulyshen, Michael D. & Kilgo, John, C.
System: The UNT Digital Library
Achieving High Reliability Operations Through Multi-Program Integration (open access)

Achieving High Reliability Operations Through Multi-Program Integration

Over the last 20 years the Idaho National Laboratory (INL) has adopted a number of operations and safety-related programs which has each periodically taken its turn in the limelight. As new programs have come along there has been natural competition for resources, focus and commitment. In the last few years, the INL has made real progress in integrating all these programs and are starting to realize important synergies. Contributing to this integration are both collaborative individuals and an emerging shared vision and goal of the INL fully maturing in its high reliability operations. This goal is so powerful because the concept of high reliability operations (and the resulting organizations) is a masterful amalgam and orchestrator of the best of all the participating programs (i.e. conduct of operations, behavior based safety, human performance, voluntary protection, quality assurance, and integrated safety management). This paper is a brief recounting of the lessons learned, thus far, at the INL in bringing previously competing programs into harmony under the goal (umbrella) of seeking to perform regularly as a high reliability organization. In addition to a brief diagram-illustrated historical review, the authors will share the INL’s primary successes (things already effectively stopped or started) and the …
Date: April 1, 2009
Creator: Ashley, Holly M.; Farris, Ronald K. & Richards, Robert E.
System: The UNT Digital Library
Actinide Targets for Neutron Cross Section Measurements (C) (open access)

Actinide Targets for Neutron Cross Section Measurements (C)

The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from “minor” actinides that currently have poorly known (n,g) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.
Date: April 1, 2006
Creator: Baker, J. D. & McGrath, C. A.
System: The UNT Digital Library
Advanced Computational Thermal Studies and their Assessment for Supercritical-Pressure Reactors (SCRs) (open access)

Advanced Computational Thermal Studies and their Assessment for Supercritical-Pressure Reactors (SCRs)

The goal of this laboratory / university collaboration of coupled computational and experimental studies is the improvement of predictive methods for supercritical-pressure reactors. The general objective is to develop supporting knowledge needed of advanced computational techniques for the technology development of the concepts and their safety systems.
Date: April 1, 2009
Creator: McEligot, D. M.; Yoo, J. Y.; Lee, J. S.; Ro, S. T.; Lurien, E.; Park, S. O. et al.
System: The UNT Digital Library
ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS (open access)

ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS

OAK A271 ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS. First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for …
Date: April 1, 2002
Creator: WONG, CPC; MALANG, S; NISHIO, S; RAFFRAY, R & SAGARA, S
System: The UNT Digital Library
Advanced Test Reactor Testing Experience: Past, Present and Future (open access)

Advanced Test Reactor Testing Experience: Past, Present and Future

The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is one of the world’s premier test reactors for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The physical configuration of the ATR, a 4-leaf clover shape, allows the reactor to be operated at different power levels in the corner “lobes” to allow for different testing conditions for multiple simultaneous experiments. The combination of high flux (maximum thermal neutron fluxes of 1E15 neutrons per square centimeter per second and maximum fast [E>1.0 MeV] neutron fluxes of 5E14 neutrons per square centimeter per second) and large test volumes (up to 48" long and 5.0" diameter) provide unique testing opportunities. The current experiments in the ATR are for a variety of test sponsors -- US government, foreign governments, private researchers, and commercial companies needing neutron irradiation services. There are three basic types of test configurations in the ATR. The simplest configuration is the sealed static capsule, wherein the target material is placed in a capsule, or plate form, and the capsule is in direct contact with the primary coolant. The next level of complexity of an experiment is an instrumented lead …
Date: April 1, 2005
Creator: Marshall, Frances M.
System: The UNT Digital Library
Aerial Measuring System Sensor Modeling (open access)

Aerial Measuring System Sensor Modeling

This project deals with the modeling the Aerial Measuring System (AMS) fixed-wing and rotary-wing sensor systems, which are critical U.S. Department of Energy's National Nuclear Security Administration (NNSA) Consequence Management assets. The fixed-wing system is critical in detecting lost or stolen radiography or medical sources, or mixed fission products as from a commercial power plant release at high flying altitudes. The helicopter is typically used at lower altitudes to determine ground contamination, such as in measuring americium from a plutonium ground dispersal during a cleanup. Since the sensitivity of these instruments as a function of altitude is crucial in estimating detection limits of various ground contaminations and necessary count times, a characterization of their sensitivity as a function of altitude and energy is needed. Experimental data at altitude as well as laboratory benchmarks is important to insure that the strong effects of air attenuation are modeled correctly. The modeling presented here is the first attempt at such a characterization of the equipment for flying altitudes. The sodium iodide (NaI) sensors utilized with these systems were characterized using the Monte Carlo N-Particle code (MCNP) developed at Los Alamos National Laboratory. For the fixed wing system, calculations modeled the spectral response for …
Date: April 1, 2002
Creator: Detwiler, R. S.
System: The UNT Digital Library
The Affect of the Hydrogen to Heavy Metal Ratio (H/HM) on Reactivity and Discharge Isotopics of Homogeneous Thoria-Urania Fuel (open access)

The Affect of the Hydrogen to Heavy Metal Ratio (H/HM) on Reactivity and Discharge Isotopics of Homogeneous Thoria-Urania Fuel

Calculations were performed using MOCUP, which includes the use of MCNP for neutron transport and ORIGEN for depletion. The MOCUP calculations were done using a unit cell (pin cell) model, where the ThO2 varied from 65-75wt% and the UO2 varied from 25-35wt%. The fission products and actinides being tracked in the calculations account for >97% of the parasitic captures in the fuel. The fuel pin was surrounded by four reflecting planes, where typical parameters were used for a 17x17 PWR assembly. The hydrogen to heavy metal ratio (H/HM) was varied by increasing or decreasing the water density in the cell. The results show that the drier lattices have insufficient reactivity due to the limited enrichment of the uranium. However, a slightly wetter lattice will increase the reactivity-limited burnup by 26% for the 25% UO2 – 75% ThO2, and 19% for the 35% UO2 – 65% ThO2 as compared to the standard coolant density. This is appears to be consistent with similar studies done with all-uranium lattices, where advantages are gained by hardening or further softening the neutron spectrum. Although some advantage is gained by softening the spectrum, the same can be said of all-uranium fueled cores. The spectral changes and, …
Date: April 1, 2002
Creator: Weaver, Kevan Dean & Herring, James Stephen
System: The UNT Digital Library
Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors (open access)

Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors

It is important to control outdoor airflow rates into HVAC systems in terms of energy conservation and healthy indoor environment. Technologies are being developed to measure outdoor air (OA) flow rates through OA intake louvers on a real time basis. The purpose of this paper is to investigate the airflow characteristics through an OA intake louver numerically in order to provide suggestions for sensor installations. Airflow patterns are simulated with and without electronic air velocity sensors within cylindrical probes installed between louver blades or at the downstream face of the louver. Numerical results show quite good agreements with experimental data, and provide insights regarding measurement system design. The simulations indicate that velocity profiles are more spatially uniform at the louver outlet relative to between louver blades, that pressure drops imposed by the sensor bars are smaller with sensor bars at the louver outlet, and that placement of the sensor bars between louver blades substantially increases air velocities inside the louver. These findings suggest there is an advantage to placing the sensor bars at the louver outlet face.
Date: April 1, 2009
Creator: Han, Hwataik; Sullivan, Douglas P. & Fisk, William J.
System: The UNT Digital Library
Ambient-Pressure X-ray Photoelectron Spectroscopy (open access)

Ambient-Pressure X-ray Photoelectron Spectroscopy

This workshop focused on the application of ambient pressure X-ray photoelectron spectroscopy (APXPS) to environmental science and catalysis. Pioneering work on APXPS was done in the early 1970's by Hans and Kai Siegbahn et al., who demonstrated that XPS can operate at pressures of up to 1 Torr. A new type of APXPS instrument that utilizes a differentially-pumped electrostatic lens system at the ALS in 2001 increased the pressure limit to above 5 Torr, which opened the door to XPS experiments on water and aqueous solutions at temperatures above the melting point, in equilibrium with the vapor pressure of water. The impact of APXPS on fields such as environmental and atmospheric science as well as heterogeneous catalysis is already visible in numerous high impact publications. Today several other synchrotron facilities around the world have already implemented beam lines for APXPS or planning to do so in the near future. The goal of this workshop (organized by Miquel Salmeron (Molecular Foundry, LBNL), B. Simon Mun (Advanced Light Source, LBNL) and Hendrik Bluhm (Chemical Sciences Division, LBNL)) was to bring together researchers interested in the technique, review its current progress, discuss scientific opportunities and desirable technical improvements as well as consider the …
Date: April 1, 2008
Creator: Bluhm, Hendrik; Bluhm, Hendrik; Mun, Bongjin Simon & Salmeron, Miquel
System: The UNT Digital Library
The amphioxus genome and the evolution of the chordate karyotype (open access)

The amphioxus genome and the evolution of the chordate karyotype

Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage with a fossil record dating back to the Cambrian. We describe the structure and gene content of the highly polymorphic {approx}520 million base pair genome of the Florida lancelet Branchiostoma floridae, and analyze it in the context of chordate evolution. Whole genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets, and vertebrates), and allow reconstruction of not only the gene complement of the last common chordate ancestor, but also a partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution.
Date: April 1, 2008
Creator: Putnam, Nicholas H.; Butts, Thomas; Ferrier, David E. K.; Furlong, Rebecca F.; Hellsten, Uffe; Kawashima, Takeshi et al.
System: The UNT Digital Library
Analysis of Residential System Strategies Targeting Least-Cost Solutions Leading to Net Zero Energy Homes: Preprint (open access)

Analysis of Residential System Strategies Targeting Least-Cost Solutions Leading to Net Zero Energy Homes: Preprint

The U. S. Department of Energy's Building America residential systems research project uses an analysis-based system research approach to identify research priorities, identify technology gaps and opportunities, establish a consistent basis to track research progress, and identify system solutions that are most likely to succeed as the initial targets for residential system research projects. This report describes the analysis approach used by the program to determine the most cost-effective pathways to achieve whole-house energy-savings goals. This report also provides an overview of design/technology strategies leading to net zero energy buildings as the basis for analysis of future residential system performance.
Date: April 1, 2006
Creator: Anderson, R.; Christensen, C. & Horowitz, S.
System: The UNT Digital Library
Analysis of the Current Use, Benefit, and Value of the Open Science Grid (open access)

Analysis of the Current Use, Benefit, and Value of the Open Science Grid

The Open Science Grid usage has ramped up more than 25% in the past twelve months due to both the increase in throughput of the core stakeholders - US LHC, LIGO and Run II - and increase in usage by nonphysics communities. It is important to understand the value collaborative projects, such as the OSG, contribute to the scientific community. This needs to be cognizant of the environment of commercial cloud offerings, the evolving and maturing middleware for grid based distributed computing, and the evolution in science and research dependence on computation. We present a first categorization of OSG value and analysis across several different aspects of the Consortium's goals and activities. And lastly, we presents some of the upcoming challenges of LHC data analysis ramp up and our ongoing contributions to the World Wide LHC Computing Grid.
Date: April 1, 2009
Creator: Pordes, R.
System: The UNT Digital Library
Analysis of the Hydrogen Infrastructure Needed to Enable Commercial Introduction of Hydrogen-Fueled Vehicles (open access)

Analysis of the Hydrogen Infrastructure Needed to Enable Commercial Introduction of Hydrogen-Fueled Vehicles

None
Date: April 1, 2005
Creator: Melendez, M.
System: The UNT Digital Library
Analysis of the ZnTe:Cu Contact on CdS/CdTe Solar Cells: Preprint (open access)

Analysis of the ZnTe:Cu Contact on CdS/CdTe Solar Cells: Preprint

We report on the recent use of cathodoluminescence (CL) to probe the depth-dependent changes in radiative recombination that occur in CdTe devices during ZnTe:Cu contacting procedures. These types of CL measurements may be useful to assist in linking impurity diffusion (e.g., Cu) from the contact with depth-dependent variation in electrical activation within the CdTe layer. Variable-energy CL suggests that diffusion from the ZnTe:Cu contact interface may assist in reducing donors levels in the CdTe bulk, and thereby yield p-type material in the region near the contact. CL analysis near abrupt metal discontinuities provides estimates of diffusion lengths for carriers associated with both excitonic and donor-to-acceptor pair recombination. Finally, CL measurements at increasing excitation levels (i.e., increasing electron-beam current) provides estimates of the defect state density, as well as providing evidence that discrete multiple defect bands may exist in CdTe prior to contacting.
Date: April 1, 2003
Creator: Gessert, T. A.; Romero, M. J.; Dhere, R. G. & Asher, S. E.
System: The UNT Digital Library
Application of a Java-based, univel geometry, neutral particle Monte Carlo code to the searchlight problem (open access)

Application of a Java-based, univel geometry, neutral particle Monte Carlo code to the searchlight problem

A univel geometry, neutral particle Monte Carlo transport code, written entirely in the Java programming language, is under development for medical radiotherapy applications. The code uses ENDF-VI based continuous energy cross section data in a flexible XML format. Full neutron-photon coupling, including detailed photon production and photonuclear reactions, is included. Charged particle equilibrium is assumed within the patient model so that detailed transport of electrons produced by photon interactions may be neglected. External beam and internal distributed source descriptions for mixed neutron-photon sources are allowed. Flux and dose tallies are performed on a univel basis. A four-tap, shift-register-sequence random number generator is used. Initial verification and validation testing of the basic neutron transport routines is underway. The searchlight problem was chosen as a suitable first application because of the simplicity of the physical model. Results show excellent agreement with analytic solutions. Computation times for similar numbers of histories are comparable to other neutron MC codes written in C and FORTRAN.
Date: April 1, 2005
Creator: Wemple, Charles A. & Cogliati, Joshua J.
System: The UNT Digital Library