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The alias method: A fast, efficient Monte Carlo sampling technique

Description: The alias method is a Monte Carlo sampling technique that offers significant advantages over more traditional methods. It equals the accuracy of table lookup and the speed of equal probable bins. The original formulation of this method sampled from discrete distributions and was easily extended to histogram distributions. We have extended the method further to applications more germane to Monte Carlo particle transport codes: continuous distributions. This paper presents the alias method as ori… more
Date: November 16, 1990
Creator: Rathkopf, James A.; Edwards, Arthur L. & Smidt, Rorbert K.
Item Type: Refine your search to only Article
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Applications of gamma-ray spectrometry in the quantitative nondestructive assay of special nuclear materials

Description: Nearly all applications of gamma-ray spectrometry in the quanitative assay of special nuclear materials can be grouped into five general categories. They are as follows: (1) Quanitative passive assay, of which transmission-corrected passive assay methods for measuring isotopic masses/concentrations are an important subset; (2) Enrichment measurements on infinitely thick'' samples for absolute determination of isotopic fractions/concentrations; (3) Measurements of isotopic ratios using relative … more
Date: April 16, 1990
Creator: Sampson, Thomas E. & Parker, Jack L.
Item Type: Refine your search to only Article
open access

(Boiling water reactor (BWR) CORA experiments)

Description: To participate in the 1990 CORA Workshop at Kernforschungszentrum Karlsruhe (KfK) GmbH, Karlsruhe, FRG, on October 1--4, and to participate in detailed discussions on October 5 with the KfK CORA Boiling Water Reactor (BWR) experiments. The traveler attended the 1990 CORA Workshop at KfK, FRG. Participation included the presentation of a paper on work performed by the Boiling Water Reactor Core Melt Progression Phenomena Program at Oak Ridge National Laboratory (ORNL) on posttest analyses of COR… more
Date: October 16, 1990
Creator: Ott, L.J.
Item Type: Refine your search to only Report
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Effect of surface modes on coupling to fast waves in the LHRF

Description: The effect of surface modes of propagation on coupling to fast waves in the LHRF is studied theoretically and experimentally. The previously reported up-down' poloidal phasing asymmetry for coupling to a uniform plasma is shown to be due to the properties of a mode which carries energy along the plasma-conducting wall interface. Comparison of the theory with coupling experiments performed on the PLT tokamak with a phased array of twelve dielectric-loaded waveguides at 800 MHz shows that the obs… more
Date: September 16, 1990
Creator: Pinsker, R. I. & Colestock, P. L.
Item Type: Refine your search to only Report
open access

Enhancing the use of coals by gas reburning-sorbent injection

Description: The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on two coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices: tangential and cyclone fired. A third unit, wall fired, is on hold'' because of funding limitations. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent … more
Date: April 16, 1990
Item Type: Refine your search to only Report
open access

Enhancing the use of coals by gas reburning-sorbent injection. Quarterly report No. 10, January 19--March 31, 1990

Description: The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on two coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices: tangential and cyclone fired. A third unit, wall fired, is ``on hold`` because of funding limitations. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percen… more
Date: April 16, 1990
Item Type: Refine your search to only Report
open access

Fast Shutdown System tests in the Georgia Tech Research Reactor

Description: The Fast Shutdown System (FSS) is a new safety system design concept being considered for in installation in the Savannah River (SRS) production reactors. This system is expected to mitigate the consequences of a Design Basis Loss of Coolant Accident, and therefore allow higher operational power levels. A test of this system in the Georgia Tech Research Reactor is proposed to demonstrate the efficacy of this concept. Three tests will be conducted at full power (5MW) and one at low power (100kw)… more
Date: March 16, 1990
Creator: Wallace, J.M.
Item Type: Refine your search to only Report
open access

Fast Shutdown System tests in the Georgia Tech Research Reactor

Description: The Fast Shutdown System (FSS) is a new safety system design concept being considered for in installation in the Savannah River (SRS) production reactors. This system is expected to mitigate the consequences of a Design Basis Loss of Coolant Accident, and therefore allow higher operational power levels. A test of this system in the Georgia Tech Research Reactor is proposed to demonstrate the efficacy of this concept. Three tests will be conducted at full power (5MW) and one at low power (100kw)… more
Date: March 16, 1990
Creator: Wallace, J. M.
Item Type: Refine your search to only Report
open access

Finite Element Analysis of G-10 Flange/Board for the CC Feedthrough Box

Description: The assembly of the stainless steel feedthrough box for the CC cryostat resulted in distortion of the slotted plates through which the circuit boards must be installed. Due to the o-ring grooves in the plates and the presence of small pump out passages it is difficult to machine the surface flat after installation. Installing the boards on the distorted surface requires distorting the g-10 flange and the board which is glued to it to match the surface distortion and achieve a seal. This results… more
Date: April 16, 1990
Creator: Wands, R.
Item Type: Refine your search to only Report
open access

First-principles study of the contractive reconstruction of gold and silver monolayers on gold, silver and aluminum

Description: Using first-principles calculations in conjunction with modeling techniques, the author has investigated the structures of Au and Ag monolayers on a number of metal surfaces. Au(100) has a c(26 {times} 68) surface unit cell and the reconstruction has been interpreted as the top layer transforming to a contracted hexagonal-close-packed layer, superimposed on the square lattice of the underlying substrate atoms. Similar reconstructions have been observed on the 5d fcc metals Ir and Pt, but not in… more
Date: November 16, 1990
Creator: Takeuchi, Noboru.
Item Type: Refine your search to only Report
open access

A ground state depleted laser in neodymium doped yttrium orthosilicate

Description: A ground state depleted (GSD){sup 1,2} laser has been demonstrated in the form of a Q-switched oscillator operating at 912 nm. Using Nd{sup 3+} as the active ion and Y{sub 2}SiO{sub 5} as the host material, the laser transition is from the lowest lying stark level of the Nd{sup 3t}F{sub 3/2} level to a stark level 355 cm{sup {minus}1} above the lowest lying one in the {sup 4}I{sub 9/2} manifold. The necessity of depleting the ground {sup 4}I{sub 9/2} manifold is evident for this level scheme as… more
Date: January 16, 1990
Creator: Beach, R.; Albrecht, G.; Solarz, R.; Krupke, W.; Comaskey, B.; Mitchell, S. et al.
Item Type: Refine your search to only Article
open access

Iterative methods for nonsymmetric systems on MIMD machines

Description: A wide variety of physical phenomena arising within many scientific disciplines can be described by systems of coupled partial differential equations (PDEs). The numerical approximation of these PDEs often involves the solution of a system of algebraic equations (possibly nonlinear) which are typically large, sparse and nonsymmetric. The increasing computational demands required by the solution of such complex scientific applications has motivated the current direction toward large-scale parall… more
Date: October 16, 1990
Creator: Shadid, J.N. & Tuminaro, R.S.
Item Type: Refine your search to only Article
open access

Laser pulse compression in strontium and calcium vapor

Description: Application of vapor pulse compression for increasing the intensity of a large copper vapor laser pumped dye laser for x-ray generation is limited by collisional absorption and nonlinear pulse breakup. We discuss measurements of these effects. 7 refs., 1 fig., 11 tabs.
Date: November 16, 1990
Creator: Crane, J. K.; Cooke, J. D.; Shaw, M. J.; Presta, R. W.; Christensen, J. J.; Johnson, M. A. et al.
Item Type: Refine your search to only Article
open access

Massively parallel Fokker-Planck calculations epilogue

Description: The purpose of this writeup is to supplement the publication, Massively Parallel Fokker-Planck Calculations,'' which appeared in the Proceedings of the Fifth Distributed Memory Computing Conference. Results obtained subsequent to that presentation are reported. This work is not self-contained; the reader should refer to that publication.
Date: October 16, 1990
Creator: Mirin, A. A.
Item Type: Refine your search to only Report
open access

Measuring the efficacy of a root biobarrier with x-ray computed tomography

Description: X-ray computed tomography is a useful tool for investigating soil physical properties nondestructively. There is a need to develop proper calibration relationships between soil properties and the x-ray absorption coefficient. The objective of the work was to evaluate soil factors affecting the x-ray absorption coefficient. Based on a theoretical analysis, experimental data from five soils and on results of several other investigators, it was concluded that for many applications, one calibration… more
Date: August 16, 1990
Creator: Tollner, E. W. & Murphy, C. E. Jr.
Item Type: Refine your search to only Report
open access

OH Module Assembly Stand

Description: There is an OR module assembly stand in use at IB4. This design has been approved by safety, as presented by Mike Foley, and has been successfully used. Another one is needed at the D-zero assembly building, but some modifications need to be made. This report will show that the new modified design is at least as strong, if not stronger, than the older IB4 design in every aspect. Since the weight distribution of the OR modules on the sling is indeterminate, this report compares three cases of su… more
Date: October 16, 1990
Creator: Bolan, P.J.
Item Type: Refine your search to only Report
open access

Ornithological Survey of the Proposed Geothermal Well Site No. 2

Description: The U.S. Fish and Wildlife Service (USFWS 1983) and the State of Hawaii (DLNR 1986) have listed as endangered six forest bird species for the Island of Hawaii. Two of these birds, the O'u (Psittirostra psittacea) and the Hawaiian hawk (Buteo solitarius) may be present within the Geothermal resource sub-zone (Scott et al. 1986). Thus, their presence could impact future development within the resource area. This report presents the results of a bird survey conducted August 11 and 12, 1990 in the … more
Date: August 16, 1990
Creator: Jeffrey, Jack
Item Type: Refine your search to only Report
open access

Photoion-photoelectron coincidence studies clusters and transient molecules

Description: Experimental photoion-photoelectron coincidence (PIPECO) spectra have been obtained at different nozzle stagnation pressures for Ar, Kr, Xe, and CO dimers and trimers in the wavelength regions corresponding to the respective ground states through all states accessible with a photon energy of 20 eV. Ionization energies for all ground states were measured and agree well with previously reported values. The formation of stable dimer ions from fragmentation of larger cluster ions initially produced… more
Date: November 16, 1990
Creator: Norwood, K.
Item Type: Refine your search to only Report
open access

Producing EGS4 shower displays with the Unified Graphics System

Description: The EGS4 Code System has been coupled with the SLAC Unified Graphics System in such a manner as to provide a means for displaying showers on UGS77-supported devices. This is most easily accomplished by attaching an auxiliary subprogram package (SHOWGRAF) to existing EGS4 User Codes and making use of a graphics display or a post-processor code called EGS4PL. SHOWGRAF may be used to create shower displays directly on interactive IBM 5080 color display devices, supporting three-dimensional rotatio… more
Date: August 16, 1990
Creator: Cowan, R.F. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Lab. for Nuclear Science) & Nelson, W.R. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))
Item Type: Refine your search to only Report
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Radiation Laboratory, University of Notre Dame

Description: The Notre Dame Radiation Laboratory is a facility of the Department of Energy operated for DOE by the University of Notre Dame. The majority of the programs within the Laboratory are supported by the Office of Basic Energy Sciences of DOE and, unless otherwise noted in the following, support can be attributed to the Office of Basic Energy Sciences. Certain additional programs, so indicated, are supported by the Office of Standard Reference Data of the National Institute of Standards and Technol… more
Date: October 16, 1990
Item Type: Refine your search to only Report
open access

The single electron chemistry of coals, January 1, 1990--March 30, 1990

Description: The Wyodak, Upper Freeport and Pocahontas No. 3 samples containing DPPD display a decrease in spin density as compared to the starting coals. Coincident with this decrease is a loss or decrease of the narrow inertinite signal in the esr spectrum of these coals. The Pittsburgh No. 8 coal sample containing DPPD also displays a loss of spin density as compared to the starting coal but there is no change in the esr spectrum. These results compare well with earlier work involving 4-vinylpyridine and… more
Date: April 16, 1990
Creator: Larsen, J. W. & Flowers II, R. A.
Item Type: Refine your search to only Report
open access

The single electron chemistry of coals, January 1, 1990--March 30, 1990

Description: The Wyodak, Upper Freeport and Pocahontas No. 3 samples containing DPPD display a decrease in spin density as compared to the starting coals. Coincident with this decrease is a loss or decrease of the narrow inertinite signal in the esr spectrum of these coals. The Pittsburgh No. 8 coal sample containing DPPD also displays a loss of spin density as compared to the starting coal but there is no change in the esr spectrum. These results compare well with earlier work involving 4-vinylpyridine and… more
Date: April 16, 1990
Creator: Larsen, John W. & Flowers, Robert A., II
Item Type: Refine your search to only Report
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