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Neutron beam irradiation study of workload dependence of SER in a microprocessor

Description: It is known that workloads are an important factor in soft error rates (SER), but it is proving difficult to find differentiating workloads for microprocessors. We have performed neutron beam irradiation studies of a commercial microprocessor under a wide variety of workload conditions from idle, performing no operations, to very busy workloads resembling real HPC, graphics, and business applications. There is evidence that the mean times to first indication of failure, MTFIF defined in Section II, may be different for some of the applications.
Date: January 1, 2009
Creator: Michalak, Sarah E; Graves, Todd L; Hong, Ted; Ackaret, Jerry; Sonny, Rao; Subhasish, Mitra et al.
Partner: UNT Libraries Government Documents Department

Neutron Beams from Deuteron Breakup at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory

Description: Accelerator-based neutron sources offer many advantages, in particular tunability of the neutron beam in energy and width to match the needs of the application. Using a recently constructed neutron beam line at the 88-Inch Cyclotron at LBNL, tunable high-intensity sources of quasi-monoenergetic and broad spectrum neutrons from deuteron breakup are under development for a variety of applications.
Date: July 31, 2007
Creator: McMahan, M.A.; Ahle, L.; Bleuel, D.L.; Bernstein, L.; Braquest, B.R.; Cerny, J. et al.
Partner: UNT Libraries Government Documents Department

A workshop on enhanced national capability for neutron scattering

Description: This two-day workshop will engage the international neutron scattering community to vet and improve the Lujan Center Strategic Plan 2007-2013 (SP07). Sponsored by the LANL SC Program Office and the University of California, the workshop will be hosted by LANSCE Professor Sunny Sinha (UCSD). Endorsement by the Spallation Neutron Source will be requested. The discussion will focus on the role that the Lujan Center will play in the national neutron scattering landscape assuming full utilization of beamlines, a refurbished LANSCE, and a 1.4-MW SNS. Because the Lujan Strategic Plan is intended to set the stage for the Signature Facility era at LANSCE, there will be some discussion of the long-pulse spallation source at Los Alamos. Breakout groups will cover several new instrument concepts, upgrades to present instruments, expanded sample environment capabilities, and a look to the future. The workshop is in keeping with a request by BES to update the Lujan strategic plan in coordination with the SNS and the broader neutron community. Workshop invitees will be drawn from the LANSCE User Group and a broad cross section of the US, European, and Pacific Rim neutron scattering research communities.
Date: January 1, 2009
Creator: Hurd, Alan J; Rhyne, James J & Lewis, Paul S
Partner: UNT Libraries Government Documents Department


Description: The program of neutron activation analysis service at Oak Ridge National Laboratory is described. The techniques used, the limits of measurement, and the general applications of the method are discussed. (T.R.H.)
Date: July 22, 1958
Creator: Leddicotte, G.W. & Reynolds, S.A.
Partner: UNT Libraries Government Documents Department

Conceptual Design of a Rapid-Cycling Synchrotron for the KFA-Juelich Spallation Neutron Source

Description: An accelerator group was established at ANL by the request of KFA-Juelich to carry out a conceptual design study and cost estimate for a rapid-cycling synchrotron as a possible first stage program on spallation neutron sources at KFA-Juelich. This set of notes is the individual notes which form the basis of the final report under this proposal prepared in January 1983. This document contains 37 papers/notes for Advanced Accelerator Development - Neutron Source Series Notes...numbered AAD-N-1 through AAD-N-37. Each note or paper is written by various authors.
Date: January 1983
Creator: ANL-KFA Study Group
Partner: UNT Libraries Government Documents Department

Review of the Lujan neutron scattering center: basic energy sciences prereport February 2009

Description: The Lujan Neutron Scattering Center (Lujan Center) at LANSCE is a designated National User Facility for neutron scattering and nuclear physics studies with pulsed beams of moderated neutrons (cold, thermal, and epithermal). As one of five experimental areas at the Los Alamos Neutron Science Center (LANSCE), the Lujan Center hosts engineers, scientists, and students from around the world. The Lujan Center consists of Experimental Room (ER) 1 (ERl) built by the Laboratory in 1977, ER2 built by the Office of Basic Energy Sciences (BES) in 1989, and the Office Building (622) also built by BES in 1989, along with a chem-bio lab, a shop, and other out-buildings. According to a 1996 Memorandum of Agreement (MOA) between the Defense Programs (DP) Office of the National Nuclear Security Agency (NNSA) and the Office of Science (SC, then the Office of Energy Research), the Lujan Center flight paths were transferred from DP to SC, including those in ERI. That MOA was updated in 2001. Under the MOA, NNSA-DP delivers neutron beam to the windows of the target crypt, outside of which BES becomes the 'landlord.' The leveraging nature of the Lujan Center on the LANSCE accelerator is a substantial annual leverage to the $11 M BES operating fund worth approximately $56 M operating cost of the linear accelerator (LINAC)-in beam delivery.
Date: January 1, 2009
Creator: Hurd, Alan J; Rhyne, James J & Lewis, Paul S
Partner: UNT Libraries Government Documents Department


Description: An investigation of the interactions between 300-Mev neutrons and xenon was made by means of a cloud chamber in a pulsed magnetic field of 21,700 gauss placed in the neutron beam of the 184-inch Berkeley cyclotron. Eighty-seven negative pion events and 257 other stars were analyzed. In addition an experimental check was made on the energy of the incoming neutrons. Classification, identification, and angular and energy distributions of prongs associated with all events are presented. Interpretations of results are given.
Date: October 17, 1956
Creator: Morris, Richard Herbert.
Partner: UNT Libraries Government Documents Department

Effect of Neutron Irradiation on Materials Subjected to Multiaxial Stress Distributions. Quarterly Progress Report, April 1-June 30, 1963

Description: Results are reported for tensile and notched tensile tests on unirradiated and irradiated A-302B steel. The tensile results indicate that neutron irradiation decreases the uniform strain, increases the yield point, and decreases the strain hardening. The notched tensile results showed an increase in the ultimate tensile strength with irradiation. (D.L.C.)
Date: August 1, 1963
Creator: Trozera, T. & Flynn, P. W.
Partner: UNT Libraries Government Documents Department


Description: Thin Li/sup 6/F and B/sub 2/O/sub 3/ films were nondestructively analyzed by bombarding them with neutrons, obtaining the pulseheight distribution of the resultant charged particles, and determinlng the number of reactions from the area under each peak in the spectrum. The results agreed within the precision of this method with results of a flame analysis. This method is more accurate and sensitive than conventional neutron activation methods. (D.C.W.)
Date: January 1, 1962
Creator: Finston, H.L.; Wellwart, Y. & Bishop, W.
Partner: UNT Libraries Government Documents Department

Lattice dynamics of LuPO{sub 4}

Description: Lutetium orthophosphate is an important nonmagnetic host material for rare-earth-activated luminescence applications. We have measured the LuPO{sub 4} phonon density of states and dispersion curves along the [{xi}00],[{xi}{xi}0], and [00{xi}] symmetry directions by neutron spectroscopy using polycrystalline and single-crystal samples. A quantitative analysis of the neutron results was carried out using a lattice-dynamical shell model.
Date: June 1996
Creator: Nipko, J. C.; Loong, C.-K.; Loewenhaupt, M.; Reichardt, W.; Braden, M. & Boatner, L. A.
Partner: UNT Libraries Government Documents Department

Detector array design

Description: Neutron scattering facility at Oak-Ridge National is used to measure residual stresses in many different materials. Neutron beam from the reactor can be used to penetrate the inner atomic distances of metals which then can be diffracted to a detector to measure the strain. The strain data later can be converted to stresses. The facility currently uses only one detector to carry the measurement. By designing an array of detectors data can be obtained at a much faster rate and or having a much better and improved resolution. The purpose of this report is to show design of such array of detectors and their movements (rotation) for possible maximum data collection at a faster rate.
Date: February 1, 1996
Creator: Lari, S.
Partner: UNT Libraries Government Documents Department

Variational correction to the FERMI beam solution

Description: We consider the time-independent, monoenergetic searchlight problem for a purely scattering, homogeneous slab with a pencil beam of nuclear particles impinging upon one surface. The scattering process is assumed sufficiently peaked in the forward direction so that the Fokker-Planck differential scattering operator can be used. Further, the slab is assumed sufficiently thin so that backscattering is negligibly small. Generally, this problem is approximated by the classic Fermi solution. A number of modifications of Fermi theory, aiming at improved accuracy, have been proposed. Here, we show that the classic Fermi solution (or any approximate solution) can I be improved via a variational formalism.
Date: October 1, 1996
Creator: Su, Bingjing & Pomraning, G.C.
Partner: UNT Libraries Government Documents Department

The structure of carbon black-elastomer composites by small-angle neutron scattering and the method of contrast variation

Description: We have been exploring the use of small-angle neutron scattering and the method of contrast variation to give a new look at a very old problem: reinforcement of elastomers by carbon black in durable rubber products. Carbon black has a hierarchy of structures consisting of particles covalently bound into aggregates, which in turn associate by weak interactions into agglomerates. We found that in one carbon black, HSA, the aggregates are rodlike, containing an average of 4-6 particles. The aggregates have an outer graphitic shell and an inner core of lower density carbon. The core is continuous throughout the carbon black aggregate. Contrast variation of swollen HSA-polyisoprene gels shows that the HSA is completely embedded in polyisoprene and that the agglomerates are formed predominantly by end on associations of the rodlike aggregates. The surface structure of the carbon black appears smooth over length scales above about 10 {angstrom}. Further studies using production carbon blacks suggest that these structural characteristics are generally present in commercial rubber composites.
Date: July 1, 1996
Creator: Hjelm, R.P.; Wampler, W. & Gerspacher, M.
Partner: UNT Libraries Government Documents Department

Radiation-induced segregation in alloy X-750

Description: Microstructural and microchemical evolution of an Alloy X-750 heat under neutron irradiation was studied in order to understand the origin of irradiation-assisted stress corrosion cracking. Both clustering of point defects and radiation-induced segregation at interfaces were observed. Although no significant changes in the precipitate structure were observed, boundaries exhibited additional depletion of Cr and Fe and enrichment of Ni.
Date: December 31, 1996
Creator: Kenik, E.A.
Partner: UNT Libraries Government Documents Department