739 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Particles"  
Results: 1 - 24 next
open access

Advanced computational methods for nodal diffusion, Monte Carlo, and S[sub N] problems

Description: This document describes progress on five efforts for improving effectiveness of computational methods for particle diffusion and transport problems in nuclear engineering: (1) Multigrid methods for obtaining rapidly converging solutions of nodal diffusion problems. A alternative line relaxation scheme is being implemented into a nodal diffusion code. Simplified P2 has been implemented into this code. (2) Local Exponential Transform method for variance reduction in Monte Carlo neutron transport … more
Date: January 1, 1993
Creator: Martin, W. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Advances in low energy neutral atom imaging techniques

Description: Recently proposed low energy neutral atom (LENA) imaging techniques use a collisional process to convert the low energy neutrals into ions before detection. At low energies, collisional processes limit the angular resolution and conversion efficiencies of these devices. However, if the intense ultraviolet light background can be suppressed, direct LENA detection is possible. We present results from a series of experiments designed to develop a novel filtering structure based on free-standing tr… more
Date: January 1, 1993
Creator: Scime, E. E.; Funsten, H. O.; McComas, D. J.; Moore, K.R. (Los Alamos National Lab., NM (United States)) & Gruntman, M. (University of Southern California, Los Angeles, CA (United States). Space Sciences Center)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Anti-gravity: The key to 21st century physics

Description: The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutatio… more
Date: January 1, 1993
Creator: Noyes, H. Pierre
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Anti-gravity: The key to 21st century physics

Description: The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutatio… more
Date: January 1, 1993
Creator: Noyes, H. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Applications of mesoscopic physics. [Dept. of Physics, UCLA, Los Angeles, California]

Description: Research activities in the area applications of mesoscopic physics to novel correlations and fluctuations of speckle patterns: imaging and tomography with multiply scattered classical waves'' are briefly summarized. The main thrust in fundamental research is in the general areas of mesoscopic effects in disordered semiconductors and metals and the related field of applications of mesoscopic physics to the subject matter of classical wave propagation through disordered scattering media. Specific… more
Date: January 1, 1993
Creator: Feng, Shechao.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Are there atmospheric neutrino oscillations

Description: The neutrino oscillation explanation ([nu][sub [mu]] [yields] [nu][sub [tau]]) of the atmospheric neutrino deficit is often discussed but is far from widely accepted. This paper discusses several experimental observations, and how a consistent picture pointing towards neutrino oscillations might develop.
Date: January 1, 1993
Creator: Goodman, M.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Assessment of the Available (Sup 233)U Cross Sections Evaluations in the Calculation of Critical Benchmark Experiments

Description: In this report we investigate the adequacy of the available {sup 233}U cross-section data for calculation of experimental critical systems. The {sup 233}U evaluations provided in two evaluated nuclear data libraries, the U. S. Data Bank [ENDF/B (Evaluated Nuclear Data Files)] and the Japanese Data Bank [JENDL (Japanese Evaluated Nuclear Data Library)] are examined. Calculations were performed for six thermal and ten fast experimental critical systems using the Sn transport XSDRNPM code. To veri… more
Date: January 1, 1993
Creator: Leal, L.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Baryon distributions in heavy ion collisions at AGS energies: An experimental overview

Description: Data on rapidity distributions of protons from the three AGS experiments E-814, E-810 and E-802 are compared on a common base to enlarge the rapidity coverage. Together they provide a unique opportunity to study the proton distributions in relativistic heavy ion reactions over the full rapidity range. Systematics of the rapidity density distributions are presented as function of centrality and mass of colliding system. Considerable stopping is achieved for the heaviest system studied, Au+Au, th… more
Date: January 1, 1993
Creator: Videbaek, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Beta and gamma decay heat measurements between 0. 1s--50,000s for neutron fission of [sup 235]U, [sup 238]U and [sup 239]Pu

Description: A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of [sup 235]U(n[sub th]ff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 [times] 5 Nal(Tl) gamma-ray spectrometer; … more
Date: January 1, 1993
Creator: Schier, W. A. & Couchell, G. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Beta decay anomalies and the 17-keV conundrum

Description: Recent developments in pursuance of the 17-keV neutrino are reviewed. Several different experiments found anomalies in [beta] decay spectra which were consistently interpreted as evidence for a heavy neutrino. On the other hand, recent null results definitively rule out the existence of a 17-keV neutrino, as well as escaping criticisms applicable to earlier experiments. While missing links remain, it seems that any strong evidence for a 17-keV neutrino has vanished. Specifically, the anomalies … more
Date: January 1, 1993
Creator: Hime, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Beyond metric gravity: Progress on PS-200

Description: The reconciliation of quantum mechanics and gravity on varying distance scales requires changes to General Relativity that may be testable implications. We briefly review the status of tests with matter of the inverse square law and the principle of equivalence, then report on progress on the drift-tube measurement section of PS- 200, the experiment to measure the gravitational acceleration of antiprotons.
Date: January 1, 1993
Creator: Goldman, T.; Brown, R. E.; Camp, J. B.; Darling, T.; Dyer, P.; Holzscheiter, M. H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Can the measurement of the cross-section of proton-capture on beryllium-7 be improved

Description: The solar neutrino problem'' arises from the discrepancy between the observations of solar neutrinos fluxes in experiments at Homestake and Kamiokande and the solar model predictions of those fluxes. Both experiments, which are sensitive mainly to high-energy neutrinos, observe fewer neutrinos than predicted by solar models. Most of the expected high-energy solar neutrinos come from the beta-decay of [sup 8]B, which is produced in the reaction [sup 7]Be(p,[gamma])[sup 8]B. A study of all of the… more
Date: January 1, 1993
Creator: Bowers, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Canyon building ventilation system dynamic model -- Parameters and validation

Description: Plant system simulation crosses many disciplines. At the core is the mimic of key components in the form of mathematical models.'' These component models are functionally integrated to represent the plant. With today's low cost high capacity computers, the whole plant can be truly and effectively reproduced in a computer model. Dynamic simulation has its roots in single loop'' design, which is still a common objective in the employment of simulation. The other common objectives are the ability … more
Date: January 1, 1993
Creator: Moncrief, B.R. (Westinghouse Savannah River Co., Aiken, SC (United States)) & Chen, F.F.K. (Bechtel National, Inc., San Francisco, CA (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Characterization of air toxics from a laboratory coal-fired combustor and utility scale power plants

Description: The target species to be analyzed in the DCM extracts are nitrated-PAH, hydroxylated-NO[sub 2]-aromatic PAH (OH-NO[sub 2]-AR/PAH), and PAH derivatives containing either a sulfur (PASH), nitrogen (PANH) or oxygen (oxy-PAH) (see Procedure 02 in the Appendix). Battelle recommends that extracts from particle size ranges A and B for both HD and LD samples be combined together for analysis. This combination will provide a sample quantity of 2.73 mg (0.88 + 0.96 + 0.48 + 0.40, from Table 6) to begin t… more
Date: January 1, 1993
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A classical instability for black strings and p-branes

Description: We investigate the evolution of small perturbations around black of strings and branes which are low energy solutions of string theory. For simplicity we focus attention on the zero charge case and show that there are unstable modes for a range of time frequency and wavelength in the extra 10 - D dimensions. These perturbations can be stabilized if the extra dimensions are compactified to a scale smaller than the minimum wavelength for which instability occurs and thus will not affect large ast… more
Date: January 1, 1993
Creator: Gregory, R. (Chicago Univ., IL (United States). Enrico Fermi Inst.) & Laflamme, R. (Los Alamos National Lab., NM (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Coal-fueled diesel emissions control technology development

Description: The objective of this project is to develop an emissions control system for a GE locomotive powered by a Coal Water Slurry (CWS) fuel diesel engine. The development effort is directed toward reducing particulate matter, SO[sub 2] and NO[sub x] emissions from the engine exhaust gas at 700--800F and 1-2 psig. The commercial system should be economically attractive while subject to limited space constraints. After testing various alternatives, a system composed of a barrier filter with sorbent inj… more
Date: January 1, 1993
Creator: Cook, C.; Gal, E.; Mengel, M. & Van Kleunen, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Collider Physics: SDC/SSC liquified fiber calorimetry. Progress report, 1992

Description: Most effort was directed toward the D-Zero experiment at Fermilab. Over 3 pb{sup {minus}1} of high-quality physics data have been obtained. Analysis of the results (wino-zino physics, squark physics), D-zero data acquisition systems efforts, and level-1 and level-2 trigger work are described. Other work concerned detector development for use at the SSC. This technology consists of using liquid scintillator-filled tubes as scintillating fibers for a ``calorimeter.`` The key issues were to demons… more
Date: 1993~
Creator: White, James T. & Huson, F. Russ
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Commissioning status of the Continuous Wave Deuterium Demonstrator

Description: Grumman Aerospace Corporation, Argonne National Laboratory, and Culham Laboratory are commissioning the Continuous Wave Deuterium Demonstrator (CWDD) in a facility at Argonne National Laboratory. CWDD is a high-brightness, high-current, 7.5-MeV negative deuterium accelerator. The 352-MHz rf accelerating cavities are cryogenically cooled with supercritical neon to reduce the rf power requirements. Installation of the accelerator into the Argonne facility began in May 1991, and first beam from th… more
Date: January 1, 1993
Creator: Hartog, P.D.; Dooling, J.; Lorello, M.; Rathke, J. (Grumman Aerospace Corp., Bethpage, NY (United States)); Carwardine, J.; Godden, D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Contained [nu] events observed in Soudan 2

Description: Atmospheric [nu][sub [mu]] and [nu][sub e] are created in cosmic ray interactions in the atmosphere, and can be detected in underground detectors. The Kamiokande and IMB water Cerenkov detectors have found fewer [nu][sub [mu]] interactions (relative to [nu][sub e]) than are expected. Results are usually expressed by the ratio: R[triple bond]([nu][sub [mu]]/[nu][sub [mu]]) measured ([nu][sub [mu]]/[nu][sub e]) predicted with R found to be less than 1. The Soudan 2 detector is an iron calorimeter… more
Date: January 1, 1993
Creator: Ambats, I.; Ayres, D. S.; Balka, L.; Barrett, W. L.; Dawson, J.; Fields, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Dead material and energy measurements in hadronic calorimeters

Description: Often the question arises as to where is the optimal place to locate [open quotes]dead[close quotes] material in a calorimeter. This material may be needed for structural reasons, for example. There needs to be a quantified answer to the question of what damage this [open quotes]dead[close quotes] material does to the performance of a calorimeter. For the purposes of this note, a hadronic calorimeter (HAD) is characterized by the mean and standard deviation of the energy measurement made by tha… more
Date: January 1, 1993
Creator: Green, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Delta-Isobar magnetic form factor in QCD

Description: We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region $0<Q^2<1GeV^2$. The QCD sum rules in external variable field are used. The obtained formfactor is in agreement with quark model predictions for the Delta-isobar magnetic moment.
Date: January 1, 1993
Creator: Belyaev, Vladimir
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design and implementation of low-Q diffractometers at spallation sources

Description: Low-Q diffractometers at spallation sources that use time of flight methods have been successfully implemented at several facilities, including the Los Alamos Neutron Scattering Center. The proposal to build new, more powerful, advanced spallation sources using advanced moderator concepts will provide luminosity greater than 20 times the brightest spallation source available today. These developments provide opportunity and challenge to expand the capabilities of present instruments with new de… more
Date: January 1, 1993
Creator: Seeger, P.A. & Hjelm, R.P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Detecting small debris using a ground-based photon counting detector

Description: We describe a sensitive technique for detecting small space debris that exploits a fast photon-counting imager. Microchannel plate detectors using crossed delay-line readout can achieve a resolution of 2048 [times] 2048 spatial pixels and a maximum count rate of about 10[sup 6] photons per second. A baseline debris-tracking system might couple this detector to a 16-cm aperture telescope. The detector yields x, y, and time information for each detected photon. When visualized in (x, y, t) space,… more
Date: January 1, 1993
Creator: Ho, C.; Priedhorsky, W. C. & Baron, M. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Detection of cold gas releases in space via low energy neutral atom imaging

Description: Low energy neutral atoms (LENAs) are produced in space plasmas by charge exchange between the ambient magnetospheric plasma ions and cold neutral atoms. Under normal conditions these cold neutrals come from the terrestrial geocorona, a shroud of few-ev hydrogen atoms surrounding the Earth. As a consequence of this charge exchange, it has become possible to remotely image many regions of the magnetosphere for the first time utilizing recently developed LENA imaging technology. In addition to the… more
Date: January 1, 1993
Creator: McComas, D. J.; Funsten, H. O.; Moore, K. R.; Scime, E. E. & Thomsen, M. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen