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Sample records for alamos neutron science

  1. Los Alamos Neutron Science Center (LANSCE) Nuclear Science Facilities

    SciTech Connect

    Nelson, Ronald Owen; Wender, Steve

    2015-06-19

    The Los Alamos Neutron Science Center (LANSCE) facilities for Nuclear Science consist of a high-energy "white" neutron source (Target 4) with 6 flight paths, three low-energy nuclear science flight paths at the Lujan Center, and a proton reaction area. The neutron beams produced at the Target 4 complement those produced at the Lujan Center because they are of much higher energy and have shorter pulse widths. The neutron sources are driven by the 800-MeV proton beam of the LANSCE linear accelerator. With these facilities, LANSCE is able to deliver neutrons with energies ranging from a milli-electron volt to several hundreds of MeV, as well as proton beams with a wide range of energy, time and intensity characteristics. The facilities, instruments and research programs are described briefly.

  2. Operational status of the Los Alamos neutron science center (LANSCE)

    SciTech Connect

    Jones, Kevin W; Erickson, John L; Schoenberg, Kurt F

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources; the thermal and cold source for the Manuel Lujan Jr. Neutron Scattering Center, the Weapons Neutron Research (WNR) high-energy neutron source, and a pulsed Ultra-Cold Neutron Source. These three sources are the foundation of strong and productive multi-disciplinary research programs that serve a diverse and robust user community. The facility also provides multiplexed beams for the production of medical radioisotopes and proton radiography of dynamic events. The recent operating history of these sources will be reviewed and plans for performance improvement will be discussed, together with the underlying drivers for the proposed LANSCE Refurbishment project. The details of this latter project are presented in a separate contribution.

  3. Los Alamos Neutron Science Center (LANSCE) accelerator timing system upgrade

    SciTech Connect

    Rybarcyk, L.J.; Shelley, F.E. Jr.

    1997-10-01

    The Los Alamos Neutron Science Center (LANSCE) 800 MeV proton linear accelerator (linac) operates at a maximum repetition rate of twice the AC power line frequency, i.e. 120 Hz. The start of each machine cycle occurs a fixed delay after each zero-crossing of the AC line voltage. Fluctuations in the AC line frequency and phase are therefore present on all linac timing signals. Proper beam acceleration along the linac requires that the timing signals remain well synchronized to the AC line. For neutron chopper spectrometers, e.g., PHAROS at the Manuel Lujan Jr. Neutron Scattering Center, accurate neutron energy selection requires that precise synchronization be maintained between the beam-on-target arrival time and the neutron chopper rotor position. This is most easily accomplished when the chopper is synchronized to a stable, fixed frequency signal. A new zero-crossing circuit which employs a Phase-Locked Loop (PLL) has been developed to increase the phase and frequency stability of the linac timing signals and thereby improve neutron chopper performance while simultaneously maintaining proper linac operation. Results of timing signal data analysis and modeling and a description of the PLL circuit are presented.

  4. Basic and Applied Science Research at the Los Alamos Neutron Science Center

    SciTech Connect

    Lisowski, Paul W.

    2005-05-24

    The Los Alamos Neutron Science Center, or LANSCE, is an accelerator-based national user facility for research in basic and applied science using four experimental areas. LANSCE has two areas that provide neutrons generated by the 800-MeV proton beam striking tungsten target systems. A third area uses the proton beam for radiography. The fourth area uses 100 MeV protons to produce medical radioisotopes. This paper describes the four LANSCE experimental areas, gives nuclear science highlights of the past operating period, and discusses plans for the future.

  5. Upgrades to the ultracold neutron source at the Los Alamos Neutron Science Center

    NASA Astrophysics Data System (ADS)

    Pattie, Robert; LANL-nEDM Collaboration

    2015-10-01

    The spallation-driven solid deutrium-based ultracold neutron (UCN) source at the Los Alamos Neutron Science Center (LANSCE) has provided a facility for precision measurements of fundamental symmetries via the decay observables from neutron beta decay for nearly a decade. In preparation for a new room temperature neutron electric dipole moment (nEDM) experiment and to increase the statistical sensitivity of all experiments using the source an effort to increase the UCN output is underway. The ultimate goal is to provide a density of 100 UCN/cc or greater in the nEDM storage cell. This upgrade includes redesign of the cold neutron moderator and UCN converter geometries, improved coupling and coating of the UCN transport system through the biological shielding, optimization of beam timing structure, and increase of the proton beam current. We will present the results of the MCNP and UCN transport simulations that led to the new design, which will be installed spring 2016, and UCN guide tests performed at LANSCE and the Institut Laue-Langevin to study the UCN transport properties of a new nickel-based guide coating.

  6. Los Alamos neutron science user facility - control system risk mitigation & updates

    SciTech Connect

    Pieck, Martin

    2011-01-05

    LANSCE User Facility is seeing continuing support and investments. The investment will sustain reliable facility operations well into the next decade. As a result, the LANSCE User Facility will continue to be a premier Neutron Science Facility at the Los Alamos National Laboratory.

  7. Operational status and life extension plans for the Los Alamos Neutron Science Center (LANSCE)

    SciTech Connect

    Garnett, Robert W; Gulley, Mark S; Jones, Kevin W; Erickson, John L

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Risk Mitigation project. The details of this latter project will also be discussed.

  8. Operational Status and Life Extension Plans for the Los Alamos Neutron Science Center (LANSCE)

    SciTech Connect

    Erickson, John L.; Rees, Daniel E.

    2011-01-01

    The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Linac Risk Mitigation (LRM) project. The details of this latter project will also be discussed.

  9. Defense, basic, and industrial research at the Los Alamos Neutron Science Center: Proceedings

    SciTech Connect

    Longshore, A.; Salgado, K.

    1995-10-01

    The Workshop on Defense, Basic, and Industrial Research at the Los Alamos Neutron Science Center gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss the use of neutrons in science-based stockpile stewardship, The workshop began with presentations by government officials, senior representatives from the three weapons laboratories, and scientific opinion leaders. Workshop participants then met in breakout sessions on the following topics: materials science and engineering; polymers, complex fluids, and biomaterials; fundamental neutron physics; applied nuclear physics; condensed matter physics and chemistry; and nuclear weapons research. They concluded that neutrons can play an essential role in science-based stockpile stewardship and that there is overlap and synergy between defense and other uses of neutrons in basic, applied, and industrial research from which defense and civilian research can benefit. This proceedings is a collection of talks and papers from the plenary, technical, and breakout session presentations. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  10. New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

    SciTech Connect

    Morris, C. L.; Brown, E. N.; Agee, C.; Bernert, T.; Bourke, M. A. M.; Burkett, M. W.; Buttler, W. T.; Byler, D. D.; Chen, C. F.; Clarke, A. J.; Cooley, J. C.; Gibbs, P. J.; Imhoff, S. D.; Jones, R.; Kwiatkowski, K.; Mariam, F. G.; Merrill, F. E.; Murray, M. M.; Olinger, C. T.; Oro, D. M.; Nedrow, P.; Saunders, A.; Terrones, G.; Trouw, F.; Tupa, D.; Vogan, W.; Winkler, B.; Wang, Z.; Zellner, M. B.

    2015-12-30

    An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recent experiments will be reviewed and concepts for new techniques are introduced.

  11. Los Alamos neutron science center nuclear weapons stewardship and unique national scientific capabilities

    SciTech Connect

    Schoenberg, Kurt F

    2010-12-15

    This presentation gives an overview of the Los Alamos Neutron Science Center (LANSCE) and its contributions to science and the nuclear weapons program. LANSCE is made of multiple experimental facilities (the Lujan Center, the Weapons Neutron Research facility (WNR), the Ultra-Cold Neutron facility (UCN), the proton Radiography facility (pRad) and the Isotope Production Facility (IPF)) served by the its kilometer long linear accelerator. Several research areas are supported, including materials and bioscience, nuclear science, materials dynamics, irradiation response and medical isotope production. LANSCE is a national user facility that supports researchers worldwide. The LANSCE Risk Mitigation program is currently in progress to update critical accelerator equipment to help extend the lifetime of LANSCE as a key user facility. The Associate Directorate of Business Sciences (ADBS) plays an important role in the continued success of LANSCE. This includes key procurement support, human resource support, technical writing support, and training support. LANSCE is also the foundation of the future signature facility MARIE (Matter-Radiation Interactions in Extremes).

  12. Bombs, Bosons and Beer Cans-Research at the Los Alamos Neutron Science Center

    NASA Astrophysics Data System (ADS)

    Pynn, Roger

    1997-04-01

    The neutron scattering community is justifiably proud of the contributions it has made to basic research in many areas of science. Information obtained using neutrons has contributed strongly to our basic understanding of phenomena in diverse systems of interest to physicists, chemists and biologists - think, for example, of how little we would know about excitations in quantum fluids, the spin-density-wave state of chromium, electronic back-donation in the bonding of organometallic compounds, or the conformation of proteins and DNA in nucleosomes without neutron scattering. However, illustrious as this history of neutron scattering may be, it is not the only type of contribution neutrons have made to our modern scientific and technological enterprise. Increasingly in recent years, we have witnessed the application of neutrons to later parts of the R&D cycle, to problems that have been called ''strategic research'' and even in areas that are ''applied research'' or ''product development''. The purpose of my talk at this meeting is to illustrate this aspect of research at spallation neutron sources, using examples of work that has been done at the Los Alamos Neutron Science Center (LANSCE). Some of this work is driven by the fact that our principal funding agency, the Office of Defense Programs within the U.S. Department of Energy, has a need to master the science behind technologies relevant to nuclear weapons. Even so, most of the examples I have picked are equally relevant to the industrial sector and several would not shame even the most devout proponent of ''pure'' research. To demonstrate the breadth of the research performed at LANSCE, I will describe examples of recent experiments in the following areas: materials texture; temperature and particle velocity measurement in reacting high explosives; radiographic imaging with protons; chemical bonding in metal-dihydride complexes; and the structure of thin adhesive layers. LANSCE operates a user program and

  13. New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

    DOE PAGESBeta

    Morris, C. L.; Brown, E. N.; Agee, C.; Bernert, T.; Bourke, M. A. M.; Burkett, M. W.; Buttler, W. T.; Byler, D. D.; Chen, C. F.; Clarke, A. J.; et al

    2015-12-30

    An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recentmore » experiments will be reviewed and concepts for new techniques are introduced.« less

  14. SPIDER: A new instrument for fission fragment research at the Los Alamos Neutron Science Center

    NASA Astrophysics Data System (ADS)

    Tovesson, Fredrik; Arnold, Charles; Blakeley, Rick; Hecht, Adam; Laptev, Alexander; Mader, Drew; Meierbachtol, Krista; Snyder, Lucas; White, Morgan

    2013-12-01

    The study of fission fragment yields and how they behave as a function of excitation energy provides insight into the process in which they are formed. Fission yields are also important for nuclear applications, as they can be used as a diagnostic tool. A new instrument, SPIDER (Spectrometer for Ion DEtermination in fission Research), is being developed for measuring fission yields as a function of incident neutron energy at the Los Alamos Neutron Science Center. The instrument employs a time-of-flight mass spectrometry method in which the velocity and kinetic energy of the fragments are measured in order to determine their mass. Additionally, by using Bragg peak spectroscopy, the charge of the fragments can be identified. A prototype instrument has been developed and preliminary results indicate that ˜ 1 mass unit resolution is feasible using this approach. A larger detector array is currently being designed, and will be used at study fission yields from thermal neutron energies up to at least 20 MeV.

  15. Design of a subcritical multiplying low-enriched uranium externally driven neutron assembly at the Los Alamos neutron science center

    SciTech Connect

    Gavron, Victor

    2008-01-01

    The Sandia Pulsed Reactor (SPR) has had a long history of supplying short intense neutron bursts to test the survivability of critical weapons components. The most recent version, SPR III, was resurrected in 2005 in support of critical survivability testing for W-76 Life Extension Program and other testing for the Qualification Alternatives to SPR program. SPR has now been decommissioned. The SPR had a cylindrical shape, with an internal cylindrical cavity where samples were placed for testing. The approximate dimensions of the cavity were 16.5 cm radius, and 38.1 cm high. The uniformity of the fluence over the entire volume was {+-} 25%. The nominal fluence was 5.4 {center_dot} 10{sup 14} n/cm{sup 2}, 1 MeV Si equivalent (Si equivalent implies that the neutron spectrum, at energies other than 1 MeV, is weighted by its relative damage potential in silicon), with a pulse duration of 55 microseconds, FWHM. We propose a new facility as a replacement to the SPR pulsed neutron capabilities, utilizing the proton linear accelerator at the Los Alamos Neutron Science Center (LANSCE). Currently, LANSCE provides neutron beams generated by the 800 MeV proton beam, over 13 decades of energy, to five different facilities. LANSCE is in the process of being refurbished; the refurbishment project (LANSCE-R) is funded and due to be completed by 2014. In parallel to the refurbishment, the experimental user program will continue and provide 3000 hours of beam per year. LANSCE is also considering upgrade options in the framework of MaRIE (Materials and Radiation Interactions in Extreme). MaRIE is planned to be the new signature facility for Los Alamos for the foreseeable future. Hence, they expect LANSCE to continue to operate and provide beams for decades t come. They propose to use the 800 MeV proton beam, extracted from the Proton Storage Ring (PSR), to initiate a neutron pulse in a sub-critical multiplying assembly, fabricated from Low-Enriched Uranium (LEU). The reason for using

  16. Klystron Modulator Design for the Los Alamos Neutron Science Center Accelerator

    SciTech Connect

    Reass, William A.; Baca, David M.; Partridge, Edward R.; Rees, Daniel E.

    2012-06-22

    This paper will describe the design of the 44 modulator systems that will be installed to upgrade the Los Alamos Neutron Science Center (LANSCE) accelerator RF system. The klystrons can operate up to 86 kV with a nominal 32 Amp beam current with a 120 Hz repetition rate and 15% duty cycle. The klystrons are a mod-anode design. The modulator is designed with analog feedback control to ensure the klystron beam current is flat-top regulated. To achieve fast switching while maintaining linear feedback control, a grid-clamp, totem-pole modulator configuration is used with an 'on' deck and an 'off' deck. The on and off deck modulators are of identical design and utilize a cascode connected planar triode, cathode driven with a high speed MOSFET. The derived feedback is connected to the planar triode grid to enable the flat-top control. Although modern design approaches suggest solid state designs may be considered, the planar triode (Eimac Y-847B) is very cost effective, is easy to integrate with the existing hardware, and provides a simplified linear feedback control mechanism. The design is very compact and fault tolerant. This paper will review the complete electrical design, operational performance, and system characterization as applied to the LANSCE installation.

  17. LOS ALAMOS NEUTRON SCIENCE CENTER CONTRIBUTIONS TO THE DEVELOPMENT OF FUTURE POWER REACTORS

    SciTech Connect

    GAVRON, VICTOR I.; HILL, TONY S.; PITCHER, ERIC J.; TOVESSON, FREDERIK K.

    2007-01-09

    The Los Alamos Neutron Science Center (LANSCE) is a large spallation neutron complex centered around an 800 MeV high-currently proton accelerator. Existing facilities include a highly-moderated neutron facility (Lujan Center) where neutrons between thermal and keV energies are produced, and the Weapons Neutron Research Center (WNR), where a bare spallation target produces neutrons between 0.1 and several hundred MeV.The LANSCE facility offers a unique capability to provide high precision nuclear data over a large energy region, including that for fast reactor systems. In an ongoing experimental program the fission and capture cross sections are being measured for a number of minor actinides relevant for Generation-IV reactors and transmutation technology. Fission experiments makes use of both the highly moderated spallation neutron spectrum at the Lujan Center, and the unmoderated high energy spectrum at WNR. By combininb measurements at these two facilities the differential fission cross section is measured relative to the {sup 235}U(n,f) standard from subthermal energies up to about 200 MeV. An elaborate data acquisition system is designed to deal with all the different types of background present when spanning 10 energy decades. The first isotope to be measured was {sup 237}Np, and the results were used to improve the current ENDF/B-VII evaluation. Partial results have also been obtained for {sup 240}Pu and {sup 242}Pu, and the final results are expected shortly. Capture cross sections are measured at LANSCE using the Detector for Advanced Neutron Capture Experiments (DANCE). This unique instrument is highly efficient in detecting radiative capture events, and can thus handle radioactive samples of half-lives as low as 100 years. A number of capture cross sections important to fast reaction applications have been measured with DANCE. The first measurement was on {sup 237}Np(n,{gamma}), and the results have been submitted for publication. Other capture

  18. Recent Research with the Detector for Advanced Neutron Capture Experiments (dance) at the LOS Alamos Neutron Science Center

    NASA Astrophysics Data System (ADS)

    Ullmann, J. L.

    2014-09-01

    The DANCE detector at Los Alamos is a 160 element, nearly 4π BaF2 detector array designed to make measurements of neutron capture on rare or radioactive nuclides. It has also been used to make measurements of gamma-ray multiplicity following capture and gamma-ray output from fission. Several examples of measurements are briefly discussed.

  19. Stripping of H- beams by residual gas in the linac at the Los Alamos neutron science center

    SciTech Connect

    Mccrady, Rodney C; Ito, Takeyasu; Cooper, Martin D; Alexander, Saunders

    2010-09-07

    The linear accelerator at the Los Alamos Neutron Science Center (LANSCE) accelerates both protons and H{sup -} ions using Cockroft-Walton-type injectors, a drift-tube linac and a coupled-cavity linac. The vacuum is maintained in the range of 10{sup -6} to 10{sup -7} Torr; the residual gas in the vacuum system results in some stripping of the electrons from the H{sup -} ions resulting in beam spill and the potential for unwanted proton beams delivered to experiments. We have measured the amount of fully-stripped H{sup -} beam (protons) that end up at approximately 800 MeV in the beam switchyard at LANSCE using image plates as very sensitive detectors. We present here the motivation for the measurement, the measurement technique and results.

  20. Los Alamos Science: Number 16

    SciTech Connect

    Cooper, N.G.

    1988-01-01

    It was an unusually stimulating day and a half at Los Alamos when two Nobel Laureates in physiology, a leading paleontologist, and a leading bio-astrophysicist came together to discuss ''Unsolved Problems in the Science of Life,'' the topic of the second in a series of special meetings sponsored by the Fellows of the Laboratory. Just like the first one on ''Creativity in Science,'' this colloquium took us into a broader arena of ideas and viewpoints than is our usual daily fare. To contemplate the evolution and mysteries of intelligent life from the speakers' diverse points of view at one time, in one place was indeed a rare experience.

  1. Neutron Capture Experiments Using the DANCE Array at Los Alamos

    SciTech Connect

    Dashdorj, D.; Mitchell, G. E.; Baramsai, B.; Chyzh, A.; Walker, C.; Agvaanluvsan, U.; Becker, J. A.; Parker, W.; Sleaford, B.; Wu, C. Y.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Krticka, M.; Becvar, F.

    2009-03-31

    The Detector for Advanced Neutron Capture Experiments (DANCE) is designed for neutron capture measurements on very small and/or radioactive targets. The DANCE array of 160 BaF{sub 2} scintillation detectors is located at the Lujan Center at the Los Alamos Neutron Science Center (LANSCE). Accurate measurements of neutron capture data are important for many current applications as well as for basic understanding of neutron capture. The gamma rays following neutron capture reactions have been studied by the time-of-flight technique using the DANCE array. The high granularity of the array allows measurements of the gamma-ray multiplicity. The gamma-ray multiplicities and energy spectra for different multiplicities can be measured and analyzed for spin and parity determination of the resolved resonances.

  2. Los Alamos Using Neutrons to Stop Nuclear Smugglers

    ScienceCinema

    Favalli, Andrea; Swinhoe, Martyn

    2014-06-02

    Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

  3. Los Alamos Using Neutrons to Stop Nuclear Smugglers

    SciTech Connect

    Favalli, Andrea; Swinhoe, Martyn

    2013-06-03

    Los Alamos National Laboratory researchers have successfully demonstrated for the first time that laser-generated neutrons can be enlisted as a useful tool in the War on Terror. The international research team used the short-pulse laser at Los Alamos's TRIDENT facility to generate a neutron beam with novel characteristics that interrogated a closed container to confirm the presence and quantity of nuclear material inside. The successful experiment paves the way for creation of a table-top-sized or truck-mounted neutron generator that could be installed at strategic locations worldwide to thwart smugglers trafficking in nuclear materials.

  4. Personnel neutron dosimetry improvements at Los Alamos National Laboratory

    SciTech Connect

    Harvey, W.F.; Hoffman, J.M.; Brake, R.J.; Bliss, J.L.

    1992-08-01

    We are investigating methods to improve neutron dosimetry at Los Alamos National Laboratory (LANL) using the track etch dosemeter CR-39. Specifically, use of CR-39 for dynamic environments, typically encountered at the LANL Plutonium Facility, is shown to be a superior method for personnel neutron dosimetry when compared to the currently used TLD system. The results of glovebox experiments simulating hydrogenous shielding used at LANL, temporal variations of neutron correction factors used at the Plutonium Facility, trial implementation at this facility and preliminary neutron spectroscopy measurements are presented and compared to reference dosimetry measurements. Our results confirm that use of a TLD system in a facility implementing hydrogenous shielding requires frequent field re-calibration. When such correction factors are not re-evaluated frequently, or are maintained at pre-shielding levels, significant (i.e., 2- to 3-fold) overestimation of the neutron dose equivalent can occur.

  5. Personnel neutron dosimetry improvements at Los Alamos National Laboratory

    SciTech Connect

    Harvey, W.F.; Hoffman, J.M.; Brake, R.J. ); Bliss, J.L. . Dept. of Nuclear Engineering)

    1992-01-01

    We are investigating methods to improve neutron dosimetry at Los Alamos National Laboratory (LANL) using the track etch dosemeter CR-39. Specifically, use of CR-39 for dynamic environments, typically encountered at the LANL Plutonium Facility, is shown to be a superior method for personnel neutron dosimetry when compared to the currently used TLD system. The results of glovebox experiments simulating hydrogenous shielding used at LANL, temporal variations of neutron correction factors used at the Plutonium Facility, trial implementation at this facility and preliminary neutron spectroscopy measurements are presented and compared to reference dosimetry measurements. Our results confirm that use of a TLD system in a facility implementing hydrogenous shielding requires frequent field re-calibration. When such correction factors are not re-evaluated frequently, or are maintained at pre-shielding levels, significant (i.e., 2- to 3-fold) overestimation of the neutron dose equivalent can occur.

  6. Post-Cold War Science and Technology at Los Alamos

    NASA Astrophysics Data System (ADS)

    Browne, John C.

    2002-04-01

    Los Alamos National Laboratory serves the nation through the development and application of leading-edge science and technology in support of national security. Our mission supports national security by: ensuring the safety, security, and reliability of the U.S. nuclear stockpile; reducing the threat of weapons of mass destruction in support of counter terrorism and homeland defense; and solving national energy, environment, infrastructure, and health security problems. We require crosscutting fundamental and advanced science and technology research to accomplish our mission. The Stockpile Stewardship Program develops and applies, advanced experimental science, computational simulation, and technology to ensure the safety and reliability of U.S. nuclear weapons in the absence of nuclear testing. This effort in itself is a grand challenge. However, the terrorist attack of September 11, 2001, reminded us of the importance of robust and vibrant research and development capabilities to meet new and evolving threats to our national security. Today through rapid prototyping we are applying new, innovative, science and technology for homeland defense, to address the threats of nuclear, chemical, and biological weapons globally. Synergistically, with the capabilities that we require for our core mission, we contribute in many other areas of scientific endeavor. For example, our Laboratory has been part of the NASA effort on mapping water on the moon and NSF/DOE projects studying high-energy astrophysical phenomena, understanding fundamental scaling phenomena of life, exploring high-temperature superconductors, investigating quantum information systems, applying neutrons to condensed-matter and nuclear physics research, developing large-scale modeling and simulations to understand complex phenomena, and exploring nanoscience that bridges the atomic to macroscopic scales. In this presentation, I will highlight some of these post-cold war science and technology advances

  7. Induction of Micronuclei in Human Fibroblasts from the Los Alamos High Energy Neutron Beam

    NASA Technical Reports Server (NTRS)

    Cox, Bradley

    2009-01-01

    The space radiation field includes a broad spectrum of high energy neutrons. Interactions between these neutrons and a spacecraft, or other material, significantly contribute to the dose equivalent for astronauts. The 15 degree beam line in the Weapons Neutron Research beam at Los Alamos Nuclear Science Center generates a neutron spectrum relatively similar to that seen in space. Human foreskin fibroblast (AG1522) samples were irradiated behind 0 to 20 cm of water equivalent shielding. The cells were exposed to either a 0.05 or 0.2 Gy entrance dose. Following irradiation, micronuclei were counted to see how the water shield affects the beam and its damage to cell nuclei. Micronuclei induction was then compared with dose equivalent data provided from a tissue equivalent proportional counter.

  8. The Los Alamos Science Pillars The Science of Signatures

    SciTech Connect

    Smith, Joshua E.; Peterson, Eugene J.

    2012-09-13

    As a national security science laboratory, Los Alamos is often asked to detect and measure the characteristics of complex systems and to use the resulting information to quantify the system's behavior. The Science of Signatures (SoS) pillar is the broad suite of technical expertise and capability that we use to accomplish this task. With it, we discover new signatures, develop new methods for detecting or measuring signatures, and deploy new detection technologies. The breadth of work at Los Alamos National Laboratory (LANL) in SoS is impressive and spans from the initial understanding of nuclear weapon performance during the Manhattan Project, to unraveling the human genome, to deploying laser spectroscopy instrumentation on Mars. Clearly, SoS is a primary science area for the Laboratory and we foresee that as it matures, new regimes of signatures will be discovered and new ways of extracting information from existing data streams will be developed. These advances will in turn drive the development of sensing instrumentation and sensor deployment. The Science of Signatures is one of three science pillars championed by the Laboratory and vital to supporting our status as a leading national security science laboratory. As with the other two pillars, Materials for the Future and Information Science and Technology for Predictive Science (IS&T), SoS relies on the integration of technical disciplines and the multidisciplinary science and engineering that is our hallmark to tackle the most difficult national security challenges. Over nine months in 2011 and 2012, a team of science leaders from across the Laboratory has worked to develop a SoS strategy that positions us for the future. The crafting of this strategy has been championed by the Chemistry, Life, and Earth Sciences Directorate, but as you will see from this document, SoS is truly an Institution-wide effort and it has engagement from every organization at the Laboratory. This process tapped the insight and

  9. Plans for an Ultra Cold Neutron source at Los Alamos

    SciTech Connect

    Seestrom, S.J.; Bowles, T.J.; Hill, R.; Greene, G.L.

    1996-10-01

    Ultra Cold Neutrons (UCN) can be produced at spallation sources using a variety of techniques. To date the technique used has been to Bragg scatter and Doppler shift cold neutrons into UCN from a moving crystal. This is particularly applicable to short-pulse spallation sources. We are presently constructing a UCN source at LANSCE using this method. In addition, large gains in UCN density should be possible using cryogenic UCN sources. Research is under way at Gatchina to demonstrate technical feasibility of a frozen deuterium source. If successful, a source of this type could be implemented at future spallation source, such as the long pulse source being planned at Los Alamos, with a UCN density that may be two orders of magnitude higher than that presently available at reactors.

  10. The Los Alamos Space Science Outreach (LASSO) Program

    NASA Astrophysics Data System (ADS)

    Barker, P. L.; Skoug, R. M.; Alexander, R. J.; Thomsen, M. F.; Gary, S. P.

    2002-12-01

    The Los Alamos Space Science Outreach (LASSO) program features summer workshops in which K-14 teachers spend several weeks at LANL learning space science from Los Alamos scientists and developing methods and materials for teaching this science to their students. The program is designed to provide hands-on space science training to teachers as well as assistance in developing lesson plans for use in their classrooms. The program supports an instructional model based on education research and cognitive theory. Students and teachers engage in activities that encourage critical thinking and a constructivist approach to learning. LASSO is run through the Los Alamos Science Education Team (SET). SET personnel have many years of experience in teaching, education research, and science education programs. Their involvement ensures that the teacher workshop program is grounded in sound pedagogical methods and meets current educational standards. Lesson plans focus on current LANL satellite projects to study the solar wind and the Earth's magnetosphere. LASSO is an umbrella program for space science education activities at Los Alamos National Laboratory (LANL) that was created to enhance the science and math interests and skills of students from New Mexico and the nation. The LASSO umbrella allows maximum leveraging of EPO funding from a number of projects (and thus maximum educational benefits to both students and teachers), while providing a format for the expression of the unique science perspective of each project.

  11. Micronuclei induction in human fibroblasts exposed in vitro to Los Alamos high-energy neutrons

    NASA Astrophysics Data System (ADS)

    Gersey, Brad; Sodolak, John; Hada, Megumi; Saganti, Prem; Wilkins, Richard; Cucinotta, Francis; Wu, Honglu

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's ICE House 30L beamline is known to generate neutrons that simulate the secondary neutron spectra of earth's atmosphere. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and International Space Station (ISS). To evaluate the biological damage, we exposed human fibroblasts in vitro to the LANSCE neutron beams without degrader at an entrance dose rate of 25 mGy/h and analyzed the micronuclei (MN) induction. The cells were also placed behind a 9.9 cm water column to study the effect of shielding in the protection of neutron induced damages. It was found that the dose response in the MN frequency was linear for the samples with and without shielding and the slope of the MN yield behind the shielding was reduced by a factor of 3.5. Compared to the MN induction in human fibroblasts exposed to a γ source at a similar low dose rate, the RBE was found to be 16.7 and 10.0 for the neutrons without and with the 9.9 cm water shielding, respectively.

  12. Micronuclei Induction in Human Fibroblasts Exposed In Vitro to Los Alamos High-Energy Neutrons

    NASA Technical Reports Server (NTRS)

    Gersey, Brad; Sodolak, John; Hada, Megumi; Saganti, Prem; Wilkins, Richard; Cucinotta, Francis; Wu, Honglu

    2006-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility#s ICE House 30L beamline is known to generate neutrons that simulate the secondary neutron spectra of earth#s atmosphere. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and International Space Station (ISS). To evaluate the biological damage, we exposed human fibroblasts in vitro to the LANSCE neutron beams without degrader at an entrance dose rate of 25 mGy/hr and analyzed the micronuclei (MN) induction. The cells were also placed behind a 9.9 cm water column to study effect of shielding in the protection of neutron induced damages. It was found that the dose response in the MN frequency was linear for the samples with and without shielding and the slope of the MN yield behind the shielding was reduced by a factor of 3.5. Compared to the MN induction in human fibroblasts exposed to a gamma source at a low dose rate, the RBE was found to be 16.7 and 10.0 for the neutrons without and with 9.9 cm water shielding, respectively.

  13. Cross section and γ-ray spectra for U238(n,γ) measured with the DANCE detector array at the Los Alamos Neutron Science Center

    NASA Astrophysics Data System (ADS)

    Ullmann, J. L.; Kawano, T.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Chyzh, A.; Wu, C. Y.; Baramsai, B.; Mitchell, G. E.; Krtička, M.

    2014-03-01

    Background: Accurate knowledge of the U238(n,γ) cross section is important for developing theoretical nuclear reaction models and for applications. However, capture cross sections are difficult to calculate accurately and often must be measured. Purpose: We seek to confirm previous measurements and test cross-section calculations with an emphasis on the unresolved resonance region from 1 to 500 keV. Method: Cross sections were measured from 10 eV to 500 keV using the DANCE detector array at the LANSCE spallation neutron source. The measurements used a thin target, 48 mg/cm2 of depleted uranium. Gamma cascade spectra were also measured to provide an additional constraint on calculations. The data are compared to cross-section calculations using the code CoH3 and cascade spectra calculations made using the code dicebox. Results: This new cross-section measurement confirms the previous data. The measured gamma-ray spectra suggest the need for additional low-lying dipole strength in the radiative strength function. New Hauser-Feshbach calculations including this strength accurately predict the capture cross section without renormalization. Conclusions: The present cross-section data confirm previous measurements. Including additional low-lying dipole strength in the radiative strength function may lead to more accurate cross-section calculations in nuclei where <Γγ> has not been measured.

  14. Nuclear science research at the WNR and LANSCE neutron sources

    SciTech Connect

    Lisowski, P.W.

    1994-06-01

    The Weapons Neutron Research (WNR) Facility and the Los Alamos Neutron Scattering Center (LANSCE) use 800 MeV proton beam from the Los Alamos Meson Physics Facility (LAMPF) to generate intense bursts of neutrons. Experiments using time-of-flight (TOF) energy determination can cover an energy range from thermal to about 2 MeV at LANSCE and 0.1 to 800 MeV at WNR. At present, three flight paths at LANSCE and six flight paths at WNR are used in basic and applied nuclear science research. In this paper we present a status report on WNR and LANSCE, discuss plans for the future, and describe three experiments recently completed or underway that use the unique features of these sources.

  15. Neutrons for technology and science

    SciTech Connect

    Aeppli, G.

    1995-10-01

    We reviewed recent work using neutrons generated at nuclear reactors an accelerator-based spallation sources. Provided that large new sources become available, neutron beams will continue to have as great an impact on technology and science as in the past.

  16. The Los Alamos neutron spectrometer for the Lunar Scout-1 mission

    NASA Technical Reports Server (NTRS)

    Auchampaugh, George; Barraclough, Bruce; Byrd, Roger; Drake, Darrell; Feldman, William; Moss, Calvin; Reedy, Robert

    1993-01-01

    We review the current status of the Los Alamos program to develop a neutron spectrometer for the Lunar Scout-1 mission, which is the first of two such missions to obtain global compositional, gravity, topography, and image maps of the lunar surface during nominal one-year missions. The neutron spectrometer will measure fast and slow (epithermal and thermal) neutrons in the ranges of 0.5 MeV to 25 MeV and 0.01 eV to more than 1 keV, respectively. The neutron spectrometer will consist of two independent instruments, a fast-neutron one, and a thermal and epithermal one. The measured neutron fluxes are very sensitive to hydrogen in the top meter of the lunar surface and provide additional information about lunar composition.

  17. Neutron Capture Reactions for Stockpile Stewardship and Basic Science

    SciTech Connect

    Parker, W; Agvaanluvsan, U; Becker, J; Wilk, P; Wu, C; Bredeweg, T; Couture, A; Haight, R; Jandel, M; O'Donnell, J; Reifarth, R; Rundberg, R; Ullmann, J; Vieira, D; Wouters, J; Sheets, S; Mitchell, G; Becvar, F; Krticka, M

    2007-08-04

    The capture process is a nuclear reaction in which a target atom captures an incident projectile, e.g. a neutron. The excited-state compound nucleus de-excites by emitting photons. This process creates an atom that has one more neutron than the target atom, so it is a different isotope of the same element. With low energy (slow) neutron projectiles, capture is the dominant reaction, other than elastic scattering. However, with very heavy nuclei, fission competes with capture as a method of de-excitation of the compound nucleus. With higher energy (faster) incident neutrons, additional reactions are also possible, such as emission of protons or emission of multiple neutrons. The probability of a particular reaction occurring (such as capture) is referred to as the cross section for that reaction. Cross sections are very dependent on the incoming neutron's energy. Capture reactions can be studied either using monoenergetic neutron sources or 'white' neutron sources. A 'white' neutron source has a wide range of neutron energies in one neutron beam. The advantage to the white neutron source is that it allows the study of cross sections as they depend on neutron energies. The Los Alamos Neutron Science Center, located at Los Alamos National Laboratory, provides an intense white neutron source. Neutrons there are created by a high-energy proton beam from a linear accelerator striking a heavy metal (tungsten) target. The neutrons range in energy from subthermal up to very fast - over 100 MeV in energy. Low-energy neutron reaction cross sections fluctuate dramatically from one target to another, and they are very difficult to predict by theoretical modeling. The cross sections for particular capture reactions are important for defense sciences, advanced reactor concepts, transmutation of radioactive wastes and nuclear astrophysics. We now have a strong collaboration between Lawrence Livermore National Laboratory, Los Alamos National Laboratory, North Carolina State

  18. A Long-Pulse Spallation Source at Los Alamos: Facility description and preliminary neutronic performance for cold neutrons

    SciTech Connect

    Russell, G.J.; Weinacht, D.J.; Pitcher, E.J.; Ferguson, P.D.

    1998-03-01

    The Los Alamos National Laboratory has discussed installing a new 1-MW spallation neutron target station in an existing building at the end of its 800-MeV proton linear accelerator. Because the accelerator provides pulses of protons each about 1 msec in duration, the new source would be a Long Pulse Spallation Source (LPSS). The facility would employ vertical extraction of moderators and reflectors, and horizontal extraction of the spallation target. An LPSS uses coupled moderators rather than decoupled ones. There are potential gains of about a factor of 6 to 7 in the time-averaged neutron brightness for cold-neutron production from a coupled liquid H{sub 2} moderator compared to a decoupled one. However, these gains come at the expense of putting ``tails`` on the neutron pulses. The particulars of the neutron pulses from a moderator (e.g., energy-dependent rise times, peak intensities, pulse widths, and decay constant(s) of the tails) are crucial parameters for designing instruments and estimating their performance at an LPSS. Tungsten is the reference target material. Inconel 718 is the reference target canister and proton beam window material, with Al-6061 being the choice for the liquid H{sub 2} moderator canister and vacuum container. A 1-MW LPSS would have world-class neutronic performance. The authors describe the proposed Los Alamos LPSS facility, and show that, for cold neutrons, the calculated time-averaged neutronic performance of a liquid H{sub 2} moderator at the 1-MW LPSS is equivalent to about 1/4th the calculated neutronic performance of the best liquid D{sub 2} moderator at the Institute Laue-Langevin reactor. They show that the time-averaged moderator neutronic brightness increases as the size of the moderator gets smaller.

  19. Los Alamos National Laboratory Science Education Programs. Quarterly progress report, April 1--June 30, 1995

    SciTech Connect

    Gill, D.

    1995-09-01

    This report is quarterly progress report on the Los Alamos National Laboratory Science Education Programs. Included in the report are dicussions on teacher and faculty enhancement, curriculum improvement, student support, educational technology, and institutional improvement.

  20. The Los Alamos Neutron Scattering Center data acquisition system

    SciTech Connect

    Nelson, R.O.; Cort, G.; Gjovig, A.; Goldstone, J.A.; McMillan, D.E.; Ross, J.; Seal, J.; Machen, D.R.

    1987-05-20

    The FASTBUS subsystem of the LANSCE data acquisition system consists of a single FASTBUS crate segment with four custom modules and a QPI interface for the VAX. Since experiments at the LANSCE facility always include a time-of-flight parameter for the detected neutron and may optionally include additional position parameters characterizing the event, a time stamp is generated for each event by the Programmable Master Clock (PMC) module. The time and any position information are latched into the Time-Of-Flight buffer (TOF) module. After all events associated with a single neutron burst have been captured in a frame buffer internal to the TOF module, each event is analyzed by the MAPPER module and reduced to a histogram address to increment in the BULKSTORE module. Software access to the histogram is provided through the QPI interface.

  1. Alterations in dose and lineal energy spectra under different shieldings in the Los Alamos high-energy neutron field

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Huff, H.; Wilkins, R.

    2000-01-01

    Nuclear interactions of space radiation with shielding materials result in alterations in dose and lineal energy spectra that depend on the specific elemental composition, density and thickness of the material. The shielding characteristics of materials have been studied using charged-particle beams and radiation transport models by examining the risk reduction using the conventional dose-equivalent approach. Secondary neutrons contribute a significant fraction of the total radiation exposure in space. An experiment to study the changes in dose and lineal energy spectra by shielding materials was carried out at the Los Alamos Nuclear Science Center neutron facility. In the energy range of about 2 to 200 MeV, this neutron spectrum is similar in shape within a factor of about 2 to the spectrum expected in the International Space Station habitable modules. It is shown that with a shielding thickness of about 5 g cm(-2), the conventional radiation risk increases, in some cases by as much as a factor of 2, but decreases with thicknesses of about of 20 g cm(-2). This suggests that care must be taken in evaluating the shielding effectiveness of a given material by including both the charged-particle and neutron components of space radiation.

  2. Chromosome Aberrations in Human Epithelial Cells Exposed Los Alamos High-Energy Secondary Neutrons: M-BAND Analysis

    NASA Technical Reports Server (NTRS)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays (GCR) with the atmosphere, spacecraft structure and planetary surfaces, contribute a significant fraction to the dose equivalent radiation measurement in crew members and passengers of commercial aviation travel as well as astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's 30L beam line (4FP30L-A/ICE House) is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecrafts like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams with an entrance dose rate of 2.5 cGy/hr, and studied the induction of chromosome aberrations that were identified with multicolor-banding in situ hybridization (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results with gamma-rays and 600 MeV/nucleon Fe ions of high dose rate at NSRL (NASA Space Radiation Laboratory at Brookhaven National Laboratory), the neutron data from the LANSCE experiments showed significantly higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intrachromosomal aberrations but few inversions were accompanied by interchromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both

  3. Multisphere neutron spectroscopy measurements at the Los Alamos National Laboratory Plutonium Facility

    SciTech Connect

    Harvey, W.F.; Hajnal, F.

    1993-06-01

    Multisphere neutron spectroscopy methods are applied to measure representative working fields within the Los Alamos National Laboratory (LANL) Plutonium Facility. This facility hosts dynamic processes, which include the fabrication of {sup 238}Pu heat sources for radioisotope generators used to power space equipment and a variety of plutonium research programs that involve recovery, hydrofluorination, and metal production. Neutron fluence per unit lethargy, as a function of neutron energy measured for locations throughout this facility, are described. Dosimeter/remmeter response functions [e.g., determined for a 22.8-cm-diameter neutron rem detector (NRD), an Anderson/Braun-type neutron ``Snoopy`` monitor, track-etch CR-39, BDI-100 bubble detectors, and Kodak type A nuclear track emulsion film, (NTA)] are folded into these spectra to calculate absolute response values of counts, tracks, or bubbles per unit-dose equivalent. The relative response values per unit- dose equivalent for bare and albedo {sup 6}LiF-based thermoluminescent dosimeters (TLDs) are also calculated to estimate response scenarios encountered with use of the LANL-TLD. These results are further compared to more conventional methods of estimating neutron spectral energies such as the ``9-to-3 ratio`` method.

  4. Los Alamos Science: The Human Genome Project. Number 20, 1992

    DOE R&D Accomplishments Database

    Cooper, N. G.; Shea, N. eds.

    1992-01-01

    This document provides a broad overview of the Human Genome Project, with particular emphasis on work being done at Los Alamos. It tries to emphasize the scientific aspects of the project, compared to the more speculative information presented in the popular press. There is a brief introduction to modern genetics, including a review of classic work. There is a broad overview of the Genome Project, describing what the project is, what are some of its major five-year goals, what are major technological challenges ahead of the project, and what can the field of biology, as well as society expect to see as benefits from this project. Specific results on the efforts directed at mapping chromosomes 16 and 5 are discussed. A brief introduction to DNA libraries is presented, bearing in mind that Los Alamos has housed such libraries for many years prior to the Genome Project. Information on efforts to do applied computational work related to the project are discussed, as well as experimental efforts to do rapid DNA sequencing by means of single-molecule detection using applied spectroscopic methods. The article introduces the Los Alamos staff which are working on the Genome Project, and concludes with brief discussions on ethical, legal, and social implications of this work; a brief glimpse of genetics as it may be practiced in the next century; and a glossary of relevant terms.

  5. Los Alamos Science: The Human Genome Project. Number 20, 1992

    SciTech Connect

    Cooper, N G; Shea, N

    1992-01-01

    This article provides a broad overview of the Human Genome Project, with particular emphasis on work being done at Los Alamos. It tries to emphasize the scientific aspects of the project, compared to the more speculative information presented in the popular press. There is a brief introduction to modern genetics, including a review of classic work. There is a broad overview of the Genome Project, describing what the project is, what are some of its major five-year goals, what are major technological challenges ahead of the project, and what can the field of biology, as well as society expect to see as benefits from this project. Specific results on the efforts directed at mapping chromosomes 16 and 5 are discussed. A brief introduction to DNA libraries is presented, bearing in mind that Los Alamos has housed such libraries for many years prior to the Genome Project. Information on efforts to do applied computational work related to the project are discussed, as well as experimental efforts to do rapid DNA sequencing by means of single-molecule detection using applied spectroscopic methods. The article introduces the Los Alamos staff which are working on the Genome Project, and concludes with brief discussions on ethical, legal, and social implications of this work; a brief glimpse of genetics as it may be practiced in the next century; and a glossary of relevant terms.

  6. Pulsed Neutron Powder Diffraction for Materials Science

    SciTech Connect

    Kamiyama, T.

    2008-03-17

    The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization (Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK). Since then, the next generation source has been pursued for 20 years, and 1MW-class spallation neutron sources will be appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (J-PARC), a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about J-PARC and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal groups have started to get fund. Those proposals include five polycrystalline diffractometers: a super high resolution powder diffractometer (SHRPD), a 0.2%-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer. SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University, whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD is a super high intensity diffractometer with the highest resolution of {delta}d/d = 0.3%. VSD can measure rapid time-dependent phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as 0.01 A{sup -1}

  7. Pulsed Neutron Powder Diffraction for Materials Science

    NASA Astrophysics Data System (ADS)

    Kamiyama, T.

    2008-03-01

    The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization (Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK). Since then, the next generation source has been pursued for 20 years, and 1MW-class spallation neutron sources will be appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (J-PARC), a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about J-PARC and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal groups have started to get fund. Those proposals include five polycrystalline diffractometers: a super high resolution powder diffractometer (SHRPD), a 0.2%-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer. SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University, whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD is a super high intensity diffractometer with the highest resolution of Δd/d = 0.3%. VSD can measure rapid time-dependent phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as 0.01 Å-1

  8. Los Alamos Science, Number 25 -- 1997: Celebrating the Neutrino

    DOE R&D Accomplishments Database

    Cooper, N. G. ed.

    1997-01-01

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  9. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    SciTech Connect

    Cooper, N.G.

    1997-12-31

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  10. Center for Materials Science, Los Alamos National Laboratory. Status report, October 1, 1990--September 30, 1991

    SciTech Connect

    Parkin, D.M.; Boring, A.M.

    1991-10-01

    This report summarizes the progress of the Center for Materials Science (CMS) from October 1, 1990 to September 30, 1991, and is the nineth such annual report. It has been a year of remarkable progress in building the programs of the Center. The extent of this progress is described in detail. The CMS was established to enhance the contribution of materials science and technology to the Laboratory`s defense, energy and scientific missions, and the Laboratory. In carrying out these responsibilities it has accepted four demanding missions: (1) Build a core group of highly rated, established materials scientists and solid state physicists. (2) Promote and support top quality, interdisciplinary materials research programs at Los Alamos. (3) Strengthen the interactions of materials science and Los Alamos with the external materials science community. and (4) Establish and maintain modern materials research facilities in a readily accessible, central location.

  11. Overview of the Science Program at the LANL Ultracold Neutron Source

    NASA Astrophysics Data System (ADS)

    Ito, Takeyasu; LANL Area B UCN Collaboration

    2015-10-01

    Los Alamos National Laboratory (LANL) currently operates a proton-beam-driven solid-deuterium-based ultracold neutron (UCN) source. It was originally built to provide UCN to the UCNA experiment, an experiment to measure the angular correlation between the neutron spin and electron emission in polarized beta decay of free neutrons. The science program at the LANL UCN source has since significantly grown. It now provides UCN to various activities including a suite of neutron beta decay experiments, R&D for the SNS nEDM experiment, detector development for the Nab experiment at the SNS, development of a new nEDM experiment at LANL, and a study of material damage due to neutron induced fission fragments. In addition, the UCN source is in the process of being upgraded and an active research program on UCN source and guide technology is taking place. In this talk, an overview of the science program at the LANL UCN source will be given.

  12. Los Alamos National Laboratory A National Science Laboratory

    SciTech Connect

    Chadwick, Mark B.

    2012-07-20

    Our mission as a DOE national security science laboratory is to develop and apply science, technology, and engineering solutions that: (1) Ensure the safety, security, and reliability of the US nuclear deterrent; (2) Protect against the nuclear threat; and (3) Solve Energy Security and other emerging national security challenges.

  13. New sources and instrumentation for neutron science

    NASA Astrophysics Data System (ADS)

    Gil, Alina

    2011-04-01

    Neutron-scattering research has a lot to do with our everyday lives. Things like medicine, food, electronics, cars and airplanes have all been improved by neutron-scattering research. Neutron research also helps scientists improve materials used in a multitude of different products, such as high-temperature superconductors, powerful lightweight magnets, stronger, lighter plastic products etc. Neutron scattering is one of the most effective ways to obtain information on both, the structure and the dynamics of condensed matter. Most of the world's neutron sources were built decades ago, and although the uses and demand for neutrons have increased throughout the years, few new sources have been built. The new construction, accelerator-based neutron source, the spallation source will provide the most intense pulsed neutron beams in the world for scientific research and industrial development. In this paper it will be described what neutrons are and what unique properties make them useful for science, how spallation source is designed to produce neutron beams and the experimental instruments that will use those beams. Finally, it will be described how past neutron research has affected our everyday lives and what we might expect from the most exciting future applications.

  14. Neutron activation analysis in the life sciences

    NASA Astrophysics Data System (ADS)

    Frontasyeva, M. V.

    2011-03-01

    Development of methods for instrumental neutron activation analysis (INAA) and their applications in the life sciences are reviewed. Emphasis is placed on epithermal activation with reactor neutrons (ENAA), and the advantages of this technique in analysis of environmental objects are shown. The results of applied INAA studies in the field of the life sciences carried out at the world's leading nuclear centers are reported. Experience in employing a radioanalytical complex at the IBR-2 reactor (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna) for such studies is summarized.

  15. Scientific Advancements and Technological Developments of High P-T Neutron Diffraction at LANSCE, Los Alamos

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Daemen, L. L.; Zhang, J.

    2003-12-01

    In-situ high P-T neutron diffraction experiments provide unique opportunities to study the crystal structure, hydrogen bonding, magnetism, and thermal parameters of light elements (eg. H, Li, B) and heavy elements (eg. Ta, U, Pu,), that are virtually impossible to determine with x-ray diffraction techniques. For example, thermoelasticity and Debye-Waller factor as function of pressure and temperature can be derived using in-situ high P-T neutron diffraction techniques. These applications can also be extended to a much broader spectrum of scientific problems. For instance, puzzles in Earth science such as the carbon cycle and the role of hydrous minerals for water exchange between lithosphere and biosphere can be directly addressed. Moreover, by introducing in-situ shear, texture of metals and minerals accompanied with phase transitions at high P-T conditions can also be studied by high P-T neutron diffraction. We have successfully conducted high P-T neutron diffraction experiments at LANSCE and achieved simultaneous high pressures and temperatures of 10 GPa and 1500 K. With an average 3-6 hours of data collection, the diffraction data are of sufficiently high quality for the determination of structural parameters and thermal vibrations. We have studied hydrous mineral (MgOD), perovskite (K.15,Na.85)MgF3, clathrate hydrates (CH4-, CO2-, and H2-), metals (Mo, Al, Zr), and amorphous materials (carbon black, BMG). The aim of our research is to accurately map bond lengths, bond angles, neighboring atomic environments, and phase stability in P-T-X space. Studies based on high-pressure neutron diffraction are important for multi-disciplinary science and we welcome researchers from all fields to use this advanced technique. We have developed a 500-ton toroidal press, TAP-98, to conduct simultaneous high P-T neutron diffraction experiments inside of HIPPO (High-Pressure and Preferred-Orientation diffractometer). We have also developed a large gem-crystal anvil cell, ZAP-01

  16. Los Alamos Life Sciences Division's biomedical and environmental research programs. Progress report, January-December 1981. [Leading abstract

    SciTech Connect

    Holland, L.M.; Stafford, C.G.

    1982-10-01

    This report summarizes research and development activities of the Los Alamos Life Sciences Division's Biomedical and Environmental Research program for the calendar year 1981. Individual reports describing the current status of projects have been entered individually into the data base.

  17. Science-based stockpile stewardship at Los Alamos National Laboratory

    SciTech Connect

    Immele, J.

    1995-10-01

    I would like to start by working from Vic Reis`s total quality management diagram in which he began with the strategy and then worked through the customer requirements-what the Department of Defense (DoD) is hoping for from the science-based stockpile stewardship program. Maybe our customer`s requirements will help guide some of the issues that we should be working on. ONe quick answer to {open_quotes}why have we adopted a science-based strategy{close_quotes} is that nuclear weapons are a 50-year responsibility, not just a 5-year responsibility, and stewardship without testing is a grand challenge. While we can do engineering maintenance and turn over and remake a few things on the short time scale, without nuclear testing, without new weapons development, and without much of the manufacturing base that we had in the past, we need to learn better just how these weapons are actually working.

  18. Neutron Science TeraGrid Gateway

    SciTech Connect

    Lynch, Vickie E; Chen, Meili; Cobb, John W; Kohl, James Arthur; Miller, Stephen D; Speirs, David A; Vazhkudai, Sudharshan S

    2010-01-01

    The unique contributions of the Neutron Science TeraGrid Gateway (NSTG) are the connection of national user facility instrument data sources to the integrated cyberinfrastructure of the National Science FoundationTeraGrid and the development of a neutron science gateway that allows neutron scientists to use TeraGrid resources to analyze their data, including comparison of experiment with simulation. The NSTG is working in close collaboration with the Spallation Neutron Source (SNS) at Oak Ridge as their principal facility partner. The SNS is a next-generation neutron source. It has completed construction at a cost of $1.4 billion and is ramping up operations. The SNS will provide an order of magnitude greater flux than any previous facility in the world and will be available to all of the nation's scientists, independent of funding source, on a peer-reviewed merit basis. With this new capability, the neutron science community is facing orders of magnitude larger data sets and is at a critical point for data analysis and simulation. There is a recognized need for new ways to manage and analyze data to optimize both beam time and scientific output. The TeraGrid is providing new capabilities in the gateway for simulations using McStas and a fitting service on distributed TeraGrid resources to improved turnaround. NSTG staff are also exploring replicating experimental data in archival storage. As part of the SNS partnership, the NSTG provides access to gateway support, cyberinfrastructure outreach, community development, and user support for the neutron science community. This community includes not only SNS staff and users but extends to all the major worldwide neutron scattering centers.

  19. Neutron Science TeraGrid Gateway

    NASA Astrophysics Data System (ADS)

    Lynch, Vickie; Chen, Meili; Cobb, John; Kohl, Jim; Miller, Steve; Speirs, David; Vazhkudai, Sudharshan

    2010-11-01

    The unique contributions of the Neutron Science TeraGrid Gateway (NSTG) are the connection of national user facility instrument data sources to the integrated cyberinfrastructure of the National Science FoundationTeraGrid and the development of a neutron science gateway that allows neutron scientists to use TeraGrid resources to analyze their data, including comparison of experiment with simulation. The NSTG is working in close collaboration with the Spallation Neutron Source (SNS) at Oak Ridge as their principal facility partner. The SNS is a next-generation neutron source. It has completed construction at a cost of 1.4 billion and is ramping up operations. The SNS will provide an order of magnitude greater flux than any previous facility in the world and will be available to all of the nation's scientists, independent of funding source, on a peer-reviewed merit basis. With this new capability, the neutron science community is facing orders of magnitude larger data sets and is at a critical point for data analysis and simulation. There is a recognized need for new ways to manage and analyze data to optimize both beam time and scientific output. The TeraGrid is providing new capabilities in the gateway for simulations using McStas and a fitting service on distributed TeraGrid resources to improved turnaround. NSTG staff are also exploring replicating experimental data in archival storage. As part of the SNS partnership, the NSTG provides access to gateway support, cyberinfrastructure outreach, community development, and user support for the neutron science community. This community includes not only SNS staff and users but extends to all the major worldwide neutron scattering centers.

  20. Neutron science opportunities at pulsed spallation neutron sources

    SciTech Connect

    Carpenter, J.M.

    1996-12-31

    Using the IPNS Upgrade plan developed at Argonne National Laboratory as a worked example of the design of a pulsed spallation neutron source, this paper explores some of the scientific applications of an advanced facility for materials science studies and the instrumentation for those purposes.

  1. Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source

    SciTech Connect

    Saunders, A.; Makela, M.; Bagdasarova, Y.; Boissevain, J.; Bowles, T. J.; Currie, S. A.; Hill, R. E.; Hogan, G.; Morris, C. L.; Mortensen, R. N.; Ramsey, J.; Seestrom, S. J.; Sondheim, W. E.; Teasdale, W.; Wang, Z.; Back, H. O.; Broussard, L. J.; Hoagland, J.; Holley, A. T.; Pattie, R. W. Jr.; and others

    2013-01-15

    In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of {approx}1500 cm{sup 3}.

  2. Integrating Safety with Science,Technology and Innovation at Los Alamos National Laboratory

    SciTech Connect

    Rich, Bethany M

    2012-04-02

    The mission of Los Alamos National Laboratory (LANL) is to develop and apply science, technology and engineering solutions to ensure the safety, security, and reliability of the U.S. nuclear deterrent; reduce global threats; and solve emerging national security challenges. The most important responsibility is to direct and conduct efforts to meet the mission with an emphasis on safety, security, and quality. In this article, LANL Environmental, Safety, and Health (ESH) trainers discuss how their application and use of a kinetic learning module (learn by doing) with a unique fall arrest system is helping to address one the most common industrial safety challenges: slips and falls. A unique integration of Human Performance Improvement (HPI), Behavior Based Safety (BBS) and elements of the Voluntary Protection Program (VPP) combined with an interactive simulator experience is being used to address slip and fall events at Los Alamos.

  3. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U

    NASA Astrophysics Data System (ADS)

    Selby, H. D.; Mac Innes, M. R.; Barr, D. W.; Keksis, A. L.; Meade, R. A.; Burns, C. J.; Chadwick, M. B.; Wallstrom, T. C.

    2010-12-01

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for 99Mo, 95Zr, 137Cs, 140Ba, 141,143Ce, and 147Nd. Modest incident-energy dependence exists for the 147Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by ˜5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for 99Mo

  4. ORNL Neutron Sciences Annual Report for 2007

    SciTech Connect

    Anderson, Ian S; Horak, Charlie M; Counce, Deborah Melinda; Ekkebus, Allen E

    2008-07-01

    This is the first annual report of the Oak Ridge National Laboratory Neutron Sciences Directorate for calendar year 2007. It describes the neutron science facilities, current developments, and future plans; highlights of the year's activities and scientific research; and information on the user program. It also contains information about education and outreach activities and about the organization and staff. The Neutron Sciences Directorate is responsible for operation of the High Flux Isotope Reactor and the Spallation Neutron Source. The main highlights of 2007 were highly successful operation and instrument commissioning at both facilities. At HFIR, the year began with the reactor in shutdown mode and work on the new cold source progressing as planned. The restart on May 16, with the cold source operating, was a significant achievement. Furthermore, measurements of the cold source showed that the performance exceeded expectations, making it one of the world's most brilliant sources of cold neutrons. HFIR finished the year having completed five run cycles and 5,880 MWd of operation. At SNS, the year began with 20 kW of beam power on target; and thanks to a highly motivated staff, we reached a record-breaking power level of 183 kW by the end of the year. Integrated beam power delivered to the target was 160 MWh. Although this is a substantial accomplishment, the next year will bring the challenge of increasing the integrated beam power delivered to 887 MWh as we chart our path toward 5,350 MWh by 2011.

  5. Los Alamos National Laboratory Science Education Program. Annual progress report, October 1, 1995--September 30, 1996

    SciTech Connect

    Gill, D.H.

    1997-01-01

    The National Teacher Enhancement program (NTEP) is a three-year, multi-laboratory effort funded by the National Science Foundation and the Department of Energy to improve elementary school science programs. The Los Alamos National Laboratory targets teachers in northern New Mexico. FY96, the third year of the program, involved 11 teams of elementary school teachers (grades 4-6) in a three-week summer session, four two-day workshops during the school year and an on-going planning and implementation process. The teams included twenty-one teachers from 11 schools. Participants earned a possible six semester hours of graduate credit for the summer institute and two hours for the academic year workshops from the University of New Mexico. The Laboratory expertise in the earth and environmental science provided the tie between the Laboratory initiatives and program content, and allowed for the design of real world problems.

  6. Material Science and Engineering with Neutron Imaging

    NASA Astrophysics Data System (ADS)

    Penumadu, D.

    This chapter summarizes some of the results related to the use of neutron imaging (radiography and tomography) as applied to the broad area of materials science and engineering research. These include multi-phase flow visualization in metal casting techniques, energy-selective imaging of materials and its use for texture and stress imaging in polycrystalline materials, characterization of discrete particle systems, flow through porous media, and stroboscopic imaging. The importance of spatial resolution and neutron detector type for given engineering applications is also addressed.

  7. A proposal for a long-pulse spallation source at Los Alamos National Laboratory

    SciTech Connect

    Pynn, R.; Weinacht, D.

    1995-12-01

    Los Alamos National Laboratory is proposing a new spallation neutron source that will provide the US with an internationally competitive facility for neutron science and technology that can be built in approximately three years for less than $100 million. The establishment of a 1-MW, long-pulse spallation source (LPSS) at the Los Alamos Neutron Science Center (LANSCE) will meet many of the present needs of scientists in the neutron scattering community and provide a significant boost to neutron research in the US. The new facility will support the development of a future, more intense spallation neutron source, that is planned by DOE`s Office of Energy Research. Together with the existing short pulse spallation source (SPSS) at the Manual Lujan, Jr. Neutron Scattering Center (MLNSC) at Los Alamos, the new LPSS will provide US scientists with a complementary pair of high-performance neutron sources to rival the world`s leading facilities in Europe.

  8. Protein structures by spallation neutron crystallography

    PubMed Central

    Langan, Paul; Fisher, Zoë; Kovalevsky, Andrii; Mustyakimov, Marat; Sutcliffe Valone, Amanda; Unkefer, Cliff; Waltman, Mary Jo; Coates, Leighton; Adams, Paul D.; Afonine, Pavel V.; Bennett, Brad; Dealwis, Chris; Schoenborn, Benno P.

    2008-01-01

    The Protein Crystallography Station at Los Alamos Neutron Science Center is a high-performance beamline that forms the core of a capability for neutron macromolecular structure and function determination. This capability also includes the Macromolecular Neutron Crystallography (MNC) consortium between Los Alamos (LANL) and Lawrence Berkeley National Laboratories for developing computational tools for neutron protein crystallography, a biological deuteration laboratory, the National Stable Isotope Production Facility, and an MNC drug design consortium between LANL and Case Western Reserve University. PMID:18421142

  9. Los Alamos National Laboratory Facility Review

    SciTech Connect

    Nelson, Ronald Owen

    2015-06-05

    This series of slides depicts the Los Alamos Neutron Science Center (LANSCE). The Center's 800-MeV linac produces H+ and H- beams as well as beams of moderated (cold to 1 MeV) and unmoderated (0.1 to 600 MeV) neutrons. Experimental facilities and their capabilities and characteristics are outlined. Among these are LENZ, SPIDER, and DANCE.

  10. 2010 Neutron Review: ORNL Neutron Sciences Progress Report

    SciTech Connect

    Bardoel, Agatha A; Counce, Deborah M; Ekkebus, Allen E; Horak, Charlie M; Nagler, Stephen E; Kszos, Lynn A

    2011-06-01

    During 2010, the Neutron Sciences Directorate focused on producing world-class science, while supporting the needs of the scientific community. As the instrument, sample environment, and data analysis tools at High Flux Isotope Reactor (HFIR ) and Spallation Neutron Source (SNS) have grown over the last year, so has promising neutron scattering research. This was an exciting year in science, technology, and operations. Some topics discussed are: (1) HFIR and SNS Experiments Take Gordon Battelle Awards for Scientific Discovery - Battelle Memorial Institute presented the inaugural Gordon Battelle Prizes for scientific discovery and technology impact in 2010. Battelle awards the prizes to recognize the most significant advancements at national laboratories that it manages or co-manages. (2) Discovery of Element 117 - As part of an international team of scientists from Russia and the United States, HFIR staff played a pivotal role in the discovery by generating the berkelium used to produce the new element. A total of six atoms of ''ununseptium'' were detected in a two-year campaign employing HFIR and the Radiochemical Engineering Development Center at Oak Ridge National Laboratory (ORNL) and the heavy-ion accelerator capabilities at the Joint Institute for Nuclear Research in Dubna, Russia. The discovery of the new element expands the understanding of the properties of nuclei at extreme numbers of protons and neutrons. The production of a new element and observation of 11 new heaviest isotopes demonstrate the increased stability of super-heavy elements with increasing neutron numbers and provide the strongest evidence to date for the existence of an island of enhanced stability for super-heavy elements. (3) Studies of Iron-Based High-Temperature Superconductors - ORNL applied its distinctive capabilities in neutron scattering, chemistry, physics, and computation to detailed studies of the magnetic excitations of iron-based superconductors (iron pnictides and

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

    SciTech Connect

    Hurd, Alan J; Rhyne, James J; Lewis, Paul S

    2009-01-01

    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.

  12. European Spallation Source and Neutron Science

    NASA Astrophysics Data System (ADS)

    Yeck, James

    2014-03-01

    International collaborations in large-scale scientific projects can link Sciences and Society. Following this goal, the European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries. Scandinavia is providing 50 percent of the construction cost whilst the other member states are providing financial support mainly via in-kind contribution from institutes, laboratories or industries of the given countries. Scientists and engineers from 35 different countries are members of the workforce in Lund who participate in its design and construction. The ESS will enable new opportunities for researchers in fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics by producing very high flux neutrons to study condensed matter physics, chemistry, biology, nuclear physics and materials science. The ESS will be up to 30 times brighter than today's leading facilities and neutron sources. A tungsten target and a 5 MW long pulse proton accelerator, composed mainly of superconducting Radio-Frequency components, are used to achieve these goals.

  13. Virtual Experiments on the Neutron Science TeraGrid Gateway

    NASA Astrophysics Data System (ADS)

    Lynch, V. E.; Cobb, J. W.; Farhi, E.; Miller, S. D.; Taylor, M.

    The TeraGrid's outreach effort to the neutron science community is creating an environment that is encouraging the exploration of advanced cyberinfrastructure being incorporated into facility operations in a way that leverages facility operations to multiply the scientific output of its users, including many NSF supported scientists in many disciplines. The Neutron Science TeraGrid Gateway serves as an exploratory incubator for several TeraGrid projects. Virtual neutron scattering experiments from one exploratory project will be highlighted.

  14. Virtual Experiments on the Neutron Science TeraGrid Gateway

    SciTech Connect

    Lynch, Vickie E; Cobb, John W; Farhi, Emmanuel N; Miller, Stephen D; Taylor, M

    2008-01-01

    The TeraGrid's outreach effort to the neutron science community is creating an environment that is encouraging the exploration of advanced cyberinfrastructure being incorporated into facility operations in a way that leverages facility operations to multiply the scientific output of its users, including many NSF supported scientists in many disciplines. The Neutron Science TeraGrid Gateway serves as an exploratory incubator for several TeraGrid projects. Virtual neutron scattering experiments from one exploratory project will be highlighted.

  15. Information about Practicums at Los Alamos

    SciTech Connect

    Bradley, Paul A.

    2012-07-24

    The Los Alamos Neutron Science Center is the premier facility for neutron science experiments ranging from cross section measurements, neutron scattering experiments, proton radiography, cold neutrons, actinide neutronic properties, and many other exciting topics. The National High Magnetic Field Laboratory is home to several powerful magnets, including the one that created the first non-destructive 100 Tesla field in March 2012. They probe the electronic structure of superconductors, magnetic properties of materials (including magneto-quantum effects). Research is also conducted in correlated materials, thermoacoustics, and magnetic properties of actinides. The Trident Laser has a unique niche with very high power, short pulse experiments, with a peak power of 10{sup 20} W in short pulse mode. Discoveries range from production of monoenergetic MeV ion beam, nonlinear kinetic plasma waves, the transition between kinetic and fluid nonlinear behavior and other laser-plasma interaction processes.

  16. Advancing Materials Science using Neutrons at Oak Ridge National Laboratory

    ScienceCinema

    Carpenter, John

    2014-06-03

    Jack Carpenter, pioneer of accelerator-based pulsed spallation neutron sources, talks about neutron science at Oak Ridge National Laboratory (ORNL) and a need for a second target station at the Spallation Neutron Source (SNS). ORNL is the Department of Energy's largest multiprogram science and energy laboratory, and is home to two scientific user facilities serving the neutron science research community: the High Flux Isotope Reactor (HFIR) and SNS. HFIR and SNS provide researchers with unmatched capabilities for understanding the structure and properties of materials, macromolecular and biological systems, and the fundamental physics of the neutron. Neutrons provide a window through which to view materials at a microscopic level that allow researchers to develop better materials and better products. Neutrons enable us to understand materials we use in everyday life. Carpenter explains the need for another station to produce long wavelength neutrons, or cold neutrons, to answer questions that are addressed only with cold neutrons. The second target station is optimized for that purpose. Modern technology depends more and more upon intimate atomic knowledge of materials, and neutrons are an ideal probe.

  17. Advancing Materials Science using Neutrons at Oak Ridge National Laboratory

    SciTech Connect

    Carpenter, John

    2014-04-24

    Jack Carpenter, pioneer of accelerator-based pulsed spallation neutron sources, talks about neutron science at Oak Ridge National Laboratory (ORNL) and a need for a second target station at the Spallation Neutron Source (SNS). ORNL is the Department of Energy's largest multiprogram science and energy laboratory, and is home to two scientific user facilities serving the neutron science research community: the High Flux Isotope Reactor (HFIR) and SNS. HFIR and SNS provide researchers with unmatched capabilities for understanding the structure and properties of materials, macromolecular and biological systems, and the fundamental physics of the neutron. Neutrons provide a window through which to view materials at a microscopic level that allow researchers to develop better materials and better products. Neutrons enable us to understand materials we use in everyday life. Carpenter explains the need for another station to produce long wavelength neutrons, or cold neutrons, to answer questions that are addressed only with cold neutrons. The second target station is optimized for that purpose. Modern technology depends more and more upon intimate atomic knowledge of materials, and neutrons are an ideal probe.

  18. Workshop on Probing Frontiers in Matter with Neutron Scattering, Wrap-up Session Chaired by John C. Browne on December 14, 1997, at Fuller Lodge, Los Alamos, New Mexico

    SciTech Connect

    Mezei, F.; Thompson, J.

    1998-12-01

    The Workshop on Probing Frontiers in Matter with Neutron Scattering consisted of a series of lectures and discussions about recent highlights in neutron scattering. In this report, we present the transcript of the concluding discussion session (wrap-up session) chaired by John C. Browne, Director of Los Alamos National Laboratory. The workshop had covered a spectrum of topics ranging from high T{sub c} superconductivity to polymer science, from glasses to molecular biology, a broad review aimed at identifying trends and future needs in condensed matter research. The focus of the wrap-up session was to summarize the workshop participants' views on developments to come. Most of the highlights presented during the workshop were the result of experiments performed at the leading reactor-based neutron scattering facilities. However, recent advances with very high power accelerators open up opportunities to develop new approaches to spallation technique that could decisively advance neutron scattering research in areas for which reactor sources are today by far the best choice. The powerful combination of neutron scattering and increasingly accurate computer modeling emerged as another area of opportunity for research in the coming decades.

  19. Los Alamos National Laboratory strategic directions

    SciTech Connect

    Hecker, S.

    1995-10-01

    It is my pleasure to welcome you to Los Alamos. I like the idea of bringing together all aspects of the research community-defense, basic science, and industrial. It is particularly important in today`s times of constrained budgets and in fields such as neutron research because I am convinced that the best science and the best applications will come from their interplay. If we do the science well, then we will do good applications. Keeping our eye focused on interesting applications will spawn new areas of science. This interplay is especially critical, and it is good to have these communities represented here today.

  20. Stockpile Stewardship: Los Alamos

    SciTech Connect

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2012-01-26

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  1. Stockpile Stewardship: Los Alamos

    ScienceCinema

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2014-08-12

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  2. Thermal and Cold Neutron Computed Tomography at the Los Alamos Neutron Scattering Center Using an Amorphous Silicon Detector Array

    SciTech Connect

    Claytor, T.N.; Schwab, M.J.; Farnum, E.H.; McDonald, T.E.; Summa, D.A.; Sheats, M.J.; Stupin, D.M.; Sievers, W.L.

    1998-07-19

    The use of the EG and G-Heimann RTM 128 or dpiX FS20 amorphous silicon (a-Si) detector array for thermal neutron radiography/computed tomography has proven to be a quick and efficient means of producing high quality digital radiographic images. The resolution, although not as good as film, is about 750 pm with the RTM and 127 pm with the dpiX array with a dynamic range in excess of 2,800. In many respects using an amorphous silicon detector is an improvement over other techniques such as imaging with a CCD camera, using a storage phosphor plate or film radiography. Unlike a CCD camera, which is highly susceptible to radiation damage, a-Si detectors can be placed in the beam directly behind the object under examination and do not require any special optics or turning mirrors. The amorphous silicon detector also allows enough data to be acquired to construct a digital image in just a few seconds (minimum gate time 40 ms) whereas film or storage plate exposures can take many minutes and then need to be digitized with a scanner. The flat panel can therefore acquire a complete 3D computed tomography data set in just a few tens of minutes. While a-Si detectors have been proposed for use in imaging neutron beams, this is the first reported implementation of such a detector for neutron imaging.

  3. Solutions for implementing time-of-flight techniques in low-angle neutron scattering, as realized on the Low-Q Diffractometer at Los Alamos

    SciTech Connect

    Hjelm, R.P. Jr.; Seeger, P.A.

    1992-12-01

    The implementation of small-angle (Low-momentum transfer) neutron scattering at pulsed spallation sources, using time of flight methods, has meant the introduction of some new ideas in instrument design, data acquisition, data reduction and computer management of the experiment and the data. Here we recount some of the salient aspects of solutions for implementing time of fight small-angle neutron scattering instruments at pulsed sources, as realized on the Low-Q Diffractometer, LQD, at Los Alamos. We consider, fortlier, some of the problems that are yet to be solved, and take a short excursion into the future of SANS instrumentation at pulsed sources.

  4. Solutions for implementing time-of-flight techniques in low-angle neutron scattering, as realized on the Low-Q Diffractometer at Los Alamos

    SciTech Connect

    Hjelm, R.P. Jr.; Seeger, P.A.

    1992-01-01

    The implementation of small-angle (Low-momentum transfer) neutron scattering at pulsed spallation sources, using time of flight methods, has meant the introduction of some new ideas in instrument design, data acquisition, data reduction and computer management of the experiment and the data. Here we recount some of the salient aspects of solutions for implementing time of fight small-angle neutron scattering instruments at pulsed sources, as realized on the Low-Q Diffractometer, LQD, at Los Alamos. We consider, fortlier, some of the problems that are yet to be solved, and take a short excursion into the future of SANS instrumentation at pulsed sources.

  5. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried

  6. Neutron Transfer Reactions: Surrogates for Neutron Capture for Basic and Applied Nuclear Science

    SciTech Connect

    Cizewski, J. A.; Peters, W. A.; Allen, J.; Hatarik, R.; Matthews, C.; O'Malley, P.; Jones, K. L.; Kozub, R. L.; Howard, J.; Patterson, N.; Paulauskas, S. V.; Rogers, J.; Sissom, D. J.; Pain, S. D.; Adekola, A.; Bardayan, D. W.; Blackmon, J. C.; Liang, F.; Nesaraja, C. D.; Pittman, S. T.

    2009-03-10

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on {sup 130,132}Sn, {sup 134}Te and {sup 75}As are discussed.

  7. Neutron transfer reactions: Surrogates for neutron capture for basic and applied nuclear science

    SciTech Connect

    Cizewski, J. A.; Jones, K. L.; Kozub, R. L.; Pain, Steven D; Peters, W. A.; Adekola, Aderemi S; Allen, J.; Bardayan, Daniel W; Becker, J.; Blackmon, Jeff C; Chae, K. Y.; Chipps, K.; Erikson, Luke; Gaddis, A. L.; Harlin, Christopher W; Hatarik, Robert; Howard, Joshua A; Jandel, M.; Johnson, Micah; Kapler, R.; Krolas, W.; Liang, J Felix; Livesay, Jake; Ma, Zhanwen; Matei, Catalin; Matthews, C.; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Patterson, N. P.; Paulauskas, Stanley; Pelham, T.; Pittman, S. T.; Radford, David C; Rogers, J.; Schmitt, Kyle; Shapira, Dan; ShrinerJr., J. F.; Sissom, D. J.; Smith, Michael Scott; Swan, T. P.; Thomas, J. S.; Vieira, D. J.; Wilhelmy, J. B.; Wilson, Gemma L

    2009-04-01

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on {sup 130,132}Sn, {sup 134}Te and {sup 75}As are discussed.

  8. The Los Alamos, Sandia, and Livermore Laboratories: Integration and collaboration solving science and technology problems for the nation

    SciTech Connect

    1994-12-01

    More than 40 years ago, three laboratories were established to take on scientific responsibility for the nation`s nuclear weapons - Los Alamos, Sandia, and Livermore. This triad of laboratories has provided the state-of-the-art science and technology to create America`s nuclear deterrent and to ensure that the weapons are safe, secure, and to ensure that the weapons are safe, secure, and reliable. These national security laboratories carried out their responsibilities through intense efforts involving almost every field of science, engineering, and technology. Today, they are recognized as three of the world`s premier research and development laboratories. This report sketches the history of the laboratories and their evolution to an integrated three-laboratory system. The characteristics that make them unique are described and some of the major contributions they have made over the years are highlighted.

  9. Low temperature nickel titanium iron shape memory alloys: Actuator engineering and investigation of deformation mechanisms using in situ neutron diffraction at Los Alamos National Laboratory

    NASA Astrophysics Data System (ADS)

    Krishnan, Vinu B.

    Shape memory alloys are incorporated as actuator elements due to their inherent ability to sense a change in temperature and actuate against external loads by undergoing a shape change as a result of a temperature-induced phase transformation. The cubic so-called austenite to the trigonal so-called R-phase transformation in NiTiFe shape memory alloys offers a practical temperature range for actuator operation at low temperatures, as it exhibits a narrow temperature-hysteresis with a desirable fatigue response. Overall, this work is an investigation of selected science and engineering aspects of low temperature NiTiFe shape memory alloys. The scientific study was performed using in situ neutron diffraction measurements at the newly developed low temperature loading capability on the Spectrometer for Materials Research at Temperature and Stress (SMARTS) at Los Alamos National Laboratory and encompasses three aspects of the behavior of Ni46.8Ti50Fe3.2 at 92 K (the lowest steady state temperature attainable with the capability). First, in order to study deformation mechanisms in the R-phase in NiTiFe, measurements were performed at a constant temperature of 92 K under external loading. Second, with the objective of examining NiTiFe in one-time, high-stroke, actuator applications (such as in safety valves), a NiTiFe sample was strained to approximately 5% (the R-phase was transformed to B19' phase in the process) at 92 K and subsequently heated to full strain recovery under a load. Third, with the objective of examining NiTiFe in cyclic, low-stroke, actuator applications (such as in cryogenic thermal switches), a NiTiFe sample was strained to 1% at 92 K and subsequently heated to full strain recovery under load. Neutron diffraction spectra were recorded at selected time and stress intervals during these experiments. The spectra were subsequently used to obtain quantitative information related to the phase-specific strain, texture and phase fraction evolution using the

  10. Neutron production from polyethylene and common spacecraft materials.

    PubMed

    Maurer, R H; Roth, D R; Kinnison, J D; Jordan, T M; Heilbronn, L H; Miller, J; Zeitlin, C J

    2001-12-01

    We report experimental measurements of neutron production from collisions of neutron beams with polyethylene blocks simulating tissue at the Los Alamos National Laboratory Neutron Science Center and 1 GeV/amu iron nuclei with spacecraft shielding materials at the Brookhaven National Laboratory AGS. PMID:12033226

  11. Biomedical neutron research at the Californium User Facility for neutron science

    SciTech Connect

    Martin, R.C.; Byrne, T.E.; Miller, L.F.

    1997-04-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact {sup 252}Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with {sup 252}Cf sources. Three projects at the CUF that demonstrate the versatility of {sup 252}Cf for biological and biomedical neutron-based research are described: future establishment of a {sup 252}Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded {sup 252}Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy.

  12. Los Alamos National Laboratory Science Education Programs. Progress report, October 1, 1994--December 31, 1994

    SciTech Connect

    Gill, D.H.

    1995-02-01

    During the 1994 summer institute NTEP teachers worked in coordination with LANL and the Los Alamos Middle School and Mountain Elementary School to gain experience in communicating on-line, to gain further information from the Internet and in using electronic Bulletin Board Systems (BBSs) to exchange ideas with other teachers. To build on their telecommunications skills, NTEP teachers participated in the International Telecommunications In Education Conference (Tel*ED `94) at the Albuquerque Convention Center on November 11 & 12, 1994. They attended the multimedia keynote address, various workshops highlighting many aspects of educational telecommunications skills, and the Telecomm Rodeo sponsored by Los Alamos National Laboratory. The Rodeo featured many presentations by Laboratory personnel and educational institutions on ways in which telecommunications technologies can be use din the classroom. Many were of the `hands-on` type, so that teachers were able to try out methods and equipment and evaluate their usefulness in their own schools and classrooms. Some of the presentations featured were the Geonet educational BBS system, the Supercomputing Challenge, and the Sunrise Project, all sponsored by LANL; the `CU-seeMe` live video software, various simulation software packages, networking help, and many other interesting and useful exhibits.

  13. The Neutron Science TeraGrid Gateway, a TeraGrid Science Gateway to Support the Spallation Neutron Source

    SciTech Connect

    Cobb, John W; Geist, Al; Kohl, James Arthur; Miller, Stephen D; Peterson, Peter F; Pike, Gregory; Reuter, Michael A; Swain, William; Vazhkudai, Sudharshan S; Vijayakumar, Nithya N

    2006-01-01

    The National Science Foundation's (NSF's) Extensible Terascale Facility (ETF), or TeraGrid [1] is entering its operational phase. An ETF science gateway effort is the Neutron Science TeraGrid Gateway (NSTG.) The Oak Ridge National Laboratory (ORNL) resource provider effort (ORNL-RP) during construction and now in operations is bridging a large scale experimental community and the TeraGrid as a large-scale national cyberinfrastructure. Of particular emphasis is collaboration with the Spallation Neutron Source (SNS) at ORNL. The U.S. Department of Energy's (DOE's) SNS [2] at ORNL will be commissioned in spring of 2006 as the world's brightest source of neutrons. Neutron science users can run experiments, generate datasets, perform data reduction, analysis, visualize results; collaborate with remotes users; and archive long term data in repositories with curation services. The ORNL-RP and the SNS data analysis group have spent 18 months developing and exploring user requirements, including the creation of prototypical services such as facility portal, data, and application execution services. We describe results from these efforts and discuss implications for science gateway creation. Finally, we show incorporation into implementation planning for the NSTG and SNS architectures. The plan is for a primarily portal-based user interaction supported by a service oriented architecture for functional implementation.

  14. Neutron activation analysis at the Californium User Facility for Neutron Science

    SciTech Connect

    Martin, R.C.; Smith, E.H.; Glasgow, D.C.; Jerde, E.A.; Marsh, D.L.; Zhao, L.

    1997-12-01

    The Californium User Facility (CUF) for Neutron Science has been established to provide {sup 252}Cf-based neutron irradiation services and research capabilities including neutron activation analysis (NAA). A major advantage of the CUF is its accessibility and controlled experimental conditions compared with those of a reactor environment The CUF maintains the world`s largest inventory of compact {sup 252}Cf neutron sources. Neutron source intensities of {le} 10{sup 11} neutrons/s are available for irradiations within a contamination-free hot cell, capable of providing thermal and fast neutron fluxes exceeding 10{sup 8} cm{sup {minus}2} s{sup {minus}1} at the sample. Total flux of {ge}10{sup 9} cm{sup {minus}2} s{sup {minus}1} is feasible for large-volume irradiation rabbits within the {sup 252}Cf storage pool. Neutron and gamma transport calculations have been performed using the Monte Carlo transport code MCNP to estimate irradiation fluxes available for sample activation within the hot cell and storage pool and to design and optimize a prompt gamma NAA (PGNAA) configuration for large sample volumes. Confirmatory NAA irradiations have been performed within the pool. Gamma spectroscopy capabilities including PGNAA are being established within the CUF for sample analysis.

  15. Los Alamos Life Sciences Division's biomedical and environmental research programs. Progress report, January-December 1980

    SciTech Connect

    Holland, L.M.; Stafford, C.G.; Bolen, S.K.

    1981-09-01

    Highlights of research progress accomplished in the Life Sciences Division during the year ending December 1980 are summarized. Reports from the following groups are included: Toxicology, Biophysics, Genetics; Environmental Pathology, Organic Chemistry, and Environmental Sciences. Individual abstracts have been prepared for 46 items for inclusion in the Energy Data Base. (RJC)

  16. Welcome to Los Alamos National Laboratory: A premier national security science laboratory

    SciTech Connect

    Wallace, Terry

    2012-06-25

    Dr Wallace presents visitors with an overview of LANL's national security science mission: stockpile stewardship, protecting against the nuclear threat, and energy security & emerging threats, which are underpinned by excellence in science/technology/engineering capabilities. He shows visitors a general Lab overview of budget, staff, and facilities before providing a more in-depth look at recent Global Security accomplishments and current programs.

  17. Neutron proton crystallography station (PCS)

    SciTech Connect

    Fisher, Zoe; Kovalevsky, Andrey; Johnson, Hannah; Mustyakimov, Marat

    2009-01-01

    The PCS (Protein Crystallography Station) at Los Alamos Neutron Science Center (LANSCE) is a unique facility in the USA that is designed and optimized for detecting and collecting neutron diffraction data from macromolecular crystals. PCS utilizes the 20 Hz spallation neutron source at LANSCE to enable time-of-flight measurements using 0.6-7.0 {angstrom} neutrons. This increases the neutron flux on the sample by using a wavelength range that is optimal for studying macromolecular crystal structures. The diagram below show a schematic of PCS and photos of the detector and instrument cave.

  18. Neutron capture cross section of 136 Xe

    NASA Astrophysics Data System (ADS)

    Daugherty, Sean; Albert, Joshua; Johnson, Tessa; O'Conner, Thomasina; Kaufman, Lisa

    2015-04-01

    136 Xe is an important 0 νββ candidate, studied in experiments such as EXO-200 and, in the future, nEXO. These experiments require a precise study of neutron capture for their background models. The neutron capture cross section of 136 Xe has been measured at the Detector for Advanced Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. A neutron beam ranging from thermal energy to 100 keV was incident on a gas cell filled with isotopically pure 136 Xe . We will discuss the measurement of partial neutron capture cross sections at thermal and first neutron resonance energies along with corresponding capture gamma cascades.

  19. Los Alamos Neutron Science Center Area-A beam window heat transfer alalysis

    SciTech Connect

    Poston, D.

    1997-07-01

    Several analyses that investigate heat transfer in the Area-A beam window were conducted. It was found that the Area-A window should be able to withstand the 1-mA, 3-cm beam of the accelerator production of tritium materials test, but that the margins to failure are small. It was also determined that when the window is subjected to the 1-mA, 3-cm beam, the inner window thermocouples should read higher than the current temperature limit of 900{degrees}C, although it is possible that the thermocouples may fail before they reach these temperatures. Another finding of this study was that the actual beam width before April 1997 was 20 to 25% greater than the harp-wire printout indicated. Finally, the effect of a copper-oxide layer on the window coolant passage was studied. The results did not indicate the presence of a large copper-oxide layer; however, the results were not conclusive.

  20. Neutron Star Science with the NuSTAR

    SciTech Connect

    Vogel, J. K.

    2015-10-16

    The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, helped scientists obtain for the first time a sensitive high-­energy X-­ray map of the sky with extraordinary resolution. This pioneering telescope has aided in the understanding of how stars explode and neutron stars are born. LLNL is a founding member of the NuSTAR project, with key personnel on its optics and science team. We used NuSTAR to observe and analyze the observations of different neutron star classes identified in the last decade that are still poorly understood. These studies not only help to comprehend newly discovered astrophysical phenomena and emission processes for members of the neutron star family, but also expand the utility of such observations for addressing broader questions in astrophysics and other physics disciplines. For example, neutron stars provide an excellent laboratory to study exotic and extreme phenomena, such as the equation of state of the densest matter known, the behavior of matter in extreme magnetic fields, and the effects of general relativity. At the same time, knowing their accurate populations has profound implications for understanding the life cycle of massive stars, star collapse, and overall galactic evolution.

  1. Advanced research capabilities for neutron science and technology: Neutron polarizers for neutron scattering

    SciTech Connect

    Penttila, S.I.; Fitzsimmons, M.R.; Delheij, P.J.

    1998-12-01

    The authors describe work on the development of polarized gaseous {sup 3}He cells, which are intended for use as neutron polarizers. Laser diode arrays polarize Rb vapor in a sample cell and the {sup 3}He is polarized via collisions. They describe development and tests of such a system at LANSCE.

  2. Los Alamos National Laboratory Overview

    SciTech Connect

    Neu, Mary

    2010-06-02

    Mary Neu, Associate Director for Chemistry, Life and Earth Sciences at Los Alamos National Laboratory, delivers opening remarks at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  3. High-Pressure Neutron Diffraction Studies for Materials Sciences and Energy Sciences

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Los Alamos High Pressure Materials Research Team

    2013-05-01

    The development of neutron diffraction under extreme pressure (P) and temperature (T) conditions is highly valuable to condensed matter physics, crystal chemistry, materials sciences, as well as earth and planetary sciences. We have incorporated a 500-ton press TAP-98 into the HiPPO diffractometer at LANSCE to conduct in situ high P-T neutron diffraction experiments. We have worked out a large gem-crystal anvil cell, ZAP, to conduct neutron diffraction experiments at high-P and low-T. The ZAP cell can be used to integrate multiple experimental techniques such as neutron diffraction, laser spectroscopy, and ultrasonic interferometery. Recently, we have developed high-P low-T gas/fluid cells in conjunction with neutron diffraction and inelastic neutron scattering instruments. These techniques enable in-situ and real-time examination of gas uptake/release processes and allow high-resolution time-dependent determination of changes in crystal structure and related reaction kinetics. We have successfully used these techniques to study the equation of state, structural phase transition, and thermo-mechanical properties of metals, ceramics, and minerals. We have conducted researches on the formation of methane and hydrogen clathrates, and hydrogen adsorption of the inclusion compounds such as the recently discovered metal-organic frameworks (MOFs). The aim of our research is to accurately map phase diagram, lattice parameters, thermal parameters, bond lengths, bond angles, neighboring atomic environments, and phase stability in P-T-X space. We are currently developing further high P-T technology with a new "true" triaxial loading press, TAP_6x, to compress cubic sample package to achieve pressures up to 20 GPa and temperatures up to 2000 K in routine experiments. The implementation of TAP_6x300 with high-pressure neutron beamlines is underway for simultaneous high P-T neutron diffraction, ultrasonic, calorimetry, radiography, and tomography studies. Studies based on high

  4. Applied Nuclear Science Research and Development progress report, June 1, 1984-May 31, 1985

    SciTech Connect

    Arthur, E.D.; Mutschlecner, A.D.

    1985-09-01

    This progress report describes the activities of the Los Alamos Applied Nuclear Science Group for June 1, 1984 through May 31, 1985. The topical content includes the theory and evaluation of nuclear cross sections; neutron cross section processing and testing; neutron activation, fission products and actinides; and core neutronics code development and application. 70 refs., 31 figs., 15 tabs. (WRF)

  5. Powder diffraction in materials science using the KENS cold-neutron source

    SciTech Connect

    Kamiyama, T.; Oikawa, K.; Akiba, E.

    1997-12-01

    Since superconductivity fever spread around the world, neutron powder diffraction has become very popular and been widely used by crystallographers, physicists, chemists, mineralogists, and materials scientists. The purpose of present paper is to show, firstly, important characteristics of time-of-flight TOF powder diffraction using cold-neutron source in the study of materials science, and, secondly, recent studies on the structure and function of batteries at the Neutron Science Laboratory (KENS) in the High Energy Accelerator Research Organization (KEK).

  6. Neutron measurement support for radiation material science in research reactors

    SciTech Connect

    Bregadze, Yu.I.; Grigor'ev, E.I.; Ivanov, V.B.; Klinov, A.V.; Kuprienko, V.A.; Starostov, B.I.; Yaryna, V.P.

    1987-07-01

    The authors discuss the need for development of a support system for unity in neutron measurement. Basic problems are outlined with regard to the support of neutron measurement unity for specialized service, such as research of working neutron fields, monitoring neutron fields during irradiation, and classification, analysis and storage of information about the controlled neutron field. Methods of realizing the metrological functions of the Metrological Center of Neutron Measurements are discussed as is the technical equipment used by the Center.

  7. Recent UCN source developments at Los Alamos

    SciTech Connect

    Seestrom, S.J.; Anaya, J.M.; Bowles, T.J.

    1998-12-01

    The most intense sources of ultra cold neutrons (UCN) have bee built at reactors where the high average thermal neutron flux can overcome the low UCN production rate to achieve usable densities of UCN. At spallation neutron sources the average flux available is much lower than at a reactor, though the peak flux can be comparable or higher. The authors have built a UCN source that attempts to take advantage of the high peak flux available at the short pulse spallation neutron source at the Los Alamos Neutron Science Center (LANSCE) to generate a useful number of UCN. In the source UCN are produced by Doppler-shifted Bragg scattering of neutrons to convert 400-m/s neutrons down into the UCN regime. This source was initially tested in 1996 and various improvements were made based on the results of the 1996 running. These improvements were implemented and tested in 1997. In sections 2 and 3 they discuss the improvements that have been made and the resulting source performance. Recently an even more interesting concept was put forward by Serebrov et al. This involves combining a solid Deuterium UCN source, previously studied by Serebrov et al., with a pulsed spallation source to achieve world record UCN densities. They have initiated a program of calculations and measurements aimed at verifying the solid Deuterium UCN source concept. The approach has been to develop an analytical capability, combine with Monte Carlo calculations of neutron production, and perform benchmark experiments to verify the validity of the calculations. Based on the calculations and measurements they plan to test a modified version of the Serebrov UCN factory. They estimate that they could produce over 1,000 UCN/cc in a 15 liter volume, using 1 {micro}amp of 800 MeV protons for two seconds every 500 seconds. They will discuss the result UCN production measurements in section 4.

  8. Detector for advanced neutron capture experiments at LANSCE

    SciTech Connect

    Ullmann, J. L.; Reifarth, R.; Haight, Robert C.; Hunt, L. F.; O'Donnell, J. M.; Bredeweg, T. A.; Wilhelmy, J. B.; Fowler, Malcolm M.; Vieira, D. J.; Wouters, J. M.; Strottman, D.; Kaeppeler, F.; Heil, M.; Chamberlin, E. P.

    2002-01-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) is a 159-element 4x barium fluoride array designed to study neutron capture on small quantities, 1 mg or less, of radioactive nuclides. It is being built on a 20 m neutron flight path which views the 'upper tier' water moderator at the Manuel J. Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center. The detector design is based on Monte Carlo calculations which have suggested ways to minimize backgrounds due to neutron scattering events. A data acquisition system based on fast transient digitizers is bcing implemented

  9. The Detector for Advanced Neutron Capture Experiments at LANSCE

    SciTech Connect

    Ullmann, J.L.; Reifarth, R.; Haight, R.C.; Hunt, L.; O'Donnell, J.M.; Rundberg, R.S.; Bredeweg, T.A.; Wilhelmy, J.B.; Fowler, M.M.; Vieira, D.J.; Wouters, J.M.; Strottman, D.D.; Kaeppeler, F.; Heil, M.; Chamberlin, E.P.

    2003-08-26

    The Detector for Advanced Neutron Capture Experiments (DANCE) is a 159-element 4{pi} barium fluoride array designed to study neutron capture on small quantities, 1 mg or less, of radioactive nuclides. It is being built on a 20 m neutron flight path which views the 'upper tier' water moderator at the Manuel J. Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center. The detector design is based on Monte Carlo calculations which have suggested ways to minimize backgrounds due to neutron scattering events. A data acquisition system based on fast transient digitizers is being implemented.

  10. Precision Measurement of Parity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

    SciTech Connect

    Bernhard Lauss; J.D. Bowman; R. Carlini; T.E. Chupp; W. Chen; S. Corvig; M. Dabaghyan; D. Desai; S.J. Freeman; T.R. Gentile; M.T. Gericke; R.C. Gillis; G.L. Greene; F.W. Hersman; T. Ino; T. Ito; G.L. Jones; M. Kandes; M. Leuschner; B. Lozowski; R. Mahurin; M. Mason; Y. Masuda; J. Mei; G.S. Mitchell; S. Muto; H. Nann; S.A. Page; S.I. Penttila; W.D. Ramsay; S. Santra; P.-N. Seo; E.I. Sharapov; T.B. Smith; W.M. Snow; W.S. Wilburn; V. Yuan; H. Zhu

    2005-10-24

    The NPD{gamma} experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the {gamma} emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon ({pi} NN) coupling constant (line integral){sub {pi}}{sup l}.

  11. Pilot Project on Women and Science. A report on women scientists at the University of New Mexico and Los Alamos National Laboratory

    SciTech Connect

    Salvaggio, R.

    1993-08-01

    In the fall of 1991, through the coordinating efforts of the University of New Mexico and Los Alamos National Laboratory, the Pilot Project on Women and Science was initiated as a year-long study of women scientists at both the university and the laboratory. Its purpose was to gather information directly from women scientists in an attempt to analyze and make recommendations concerning the professional and cultural environment for women in the sciences. This report is an initial attempt to understand the ways in which women scientists view themselves, their profession, and the scientific culture they inhabit. By recording what these women say about their backgrounds and educational experiences, their current positions, the difficult negotiations many have made between their personal and professional lives, and their relative positions inside and outside the scientific community, the report calls attention both to the individual perspectives offered by these women and to the common concerns they share.

  12. Los Alamos personnel and area criticality dosimeter systems

    SciTech Connect

    Vasilik, D.G.; Martin, R.W.

    1981-06-01

    Fissionable materials are handled and processed at the Los Alamos National Laboratory. Although the probability of a nuclear criticality accident is very remote, it must be considered. Los Alamos maintains a broad spectrum of dose assessment capabilities. This report describes the methods employed for personnel neutron, area neutron, and photon dose evaluations with passive dosimetry systems.

  13. The Dynamic Albedo of Neutrons (DAN) experiment for NASA's 2009 Mars Science Laboratory.

    PubMed

    Litvak, M L; Mitrofanov, I G; Barmakov, Yu N; Behar, A; Bitulev, A; Bobrovnitsky, Yu; Bogolubov, E P; Boynton, W V; Bragin, S I; Churin, S; Grebennikov, A S; Konovalov, A; Kozyrev, A S; Kurdumov, I G; Krylov, A; Kuznetsov, Yu P; Malakhov, A V; Mokrousov, M I; Ryzhkov, V I; Sanin, A B; Shvetsov, V N; Smirnov, G A; Sholeninov, S; Timoshenko, G N; Tomilina, T M; Tuvakin, D V; Tretyakov, V I; Troshin, V S; Uvarov, V N; Varenikov, A; Vostrukhin, A

    2008-06-01

    We present a summary of the physical principles and design of the Dynamic Albedo of Neutrons (DAN) instrument onboard NASA's 2009 Mars Science Laboratory (MSL) mission. The DAN instrument will use the method of neutron-neutron activation analysis in a space application to study the abundance and depth distribution of water in the martian subsurface along the path of the MSL rover. PMID:18598140

  14. Current applications of neutron scattering in condensed matter physics, materials science and engineering

    NASA Astrophysics Data System (ADS)

    Cywinski, R.

    1997-02-01

    A brief review is presented of the current applications of neutron scattering in the fields of magnetism, highly correlated electron systems, materials science and industrial applications, as represented by presentations at ECNS'96.

  15. Effects of geochemical composition on neutron die-away measurements: Implications for Mars Science Laboratory's Dynamic Albedo of Neutrons experiment

    NASA Astrophysics Data System (ADS)

    Hardgrove, C.; Moersch, J.; Drake, D.

    2011-12-01

    The Dynamic Albedo of Neutrons (DAN) experiment, part of the scientific payload of the Mars Science Laboratory (MSL) rover mission, will have the ability to assess both the abundance and the burial depth of subsurface hydrogen as the rover traverses the Martian surface. DAN will employ a method of measuring neutron fluxes called “neutron die-away” that has not been used in previous planetary exploration missions. This method requires the use of a pulsed neutron generator that supplements neutrons produced via spallation in the subsurface by the cosmic ray background. It is well established in neutron remote sensing that low-energy (thermal) neutrons are sensitive not only to hydrogen content, but also to the macroscopic absorption cross-section of near-surface materials. To better understand the results that will be forthcoming from DAN, we model the effects of varying abundances of high absorption cross-section elements that are likely to be found on the Martian surface (Cl, Fe) on neutron die-away measurements made from a rover platform. Previously, the Mars Exploration Rovers (MER) Spirit and Opportunity found that elevated abundances of these two elements are commonly associated with locales that have experienced some form of aqueous activity in the past, even though hydrogen-rich materials are not necessarily still present. By modeling a suite of H and Cl compositions, we demonstrate that (for abundance ranges reasonable for Mars) both the elements will significantly affect DAN thermal neutron count rates. Additionally, we show that the timing of thermal neutron arrivals at the detector can be used together with the thermal neutron count rates to independently determine the abundances of hydrogen and high neutron absorption cross-section elements (the most important being Cl). Epithermal neutron die-away curves may also be used to separate these two components. We model neutron scattering in actual Martian compositions that were determined by the MER Alpha

  16. New Pulsed Cold Neutron Beam Line for Fundamental Nuclear Physics at LANSCE.

    PubMed

    Seo, P-N; Bowman, J D; Gericke, M; Gillis, R C; Greene, G L; Leuschner, M B; Long, J; Mahurin, R; Mitchell, G S; Penttila, S I; Peralta, G; Sharapov, E I; Wilburn, W S

    2005-01-01

    The NPDGamma collaboration has completed the construction of a pulsed cold neutron beam line on flight path12 at the Los Alamos Neutron Science Center (LANSCE). We describe the new beam line and characteristics of the beam. We report results of the moderator brightness and the guide performance measurements. FP12 has the highest pulsed cold neutron intensity for nuclear physics in the world. PMID:27308111

  17. New Pulsed Cold Neutron Beam Line for Fundamental Nuclear Physics at LANSCE

    PubMed Central

    Seo, P.-N.; Bowman, J. D.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Leuschner, M. B.; Long, J.; Mahurin, R.; Mitchell, G. S.; Penttila, S. I.; Peralta, G.; Sharapov, E. I.; Wilburn, W. S.

    2005-01-01

    The NPDGamma collaboration has completed the construction of a pulsed cold neutron beam line on flight path12 at the Los Alamos Neutron Science Center (LANSCE). We describe the new beam line and characteristics of the beam. We report results of the moderator brightness and the guide performance measurements. FP12 has the highest pulsed cold neutron intensity for nuclear physics in the world. PMID:27308111

  18. Edward Teller Returns to LOS Alamos

    NASA Astrophysics Data System (ADS)

    Hecker, Siegfried S.

    2010-01-01

    I was asked to share some reflections of Edward Teller's return to Los Alamos during my directorship. I met Teller late in his life. My comments focus on that time and they will be mostly in the form of stories of my interactions and those of my colleagues with Teller. Although the focus of this symposium is on Teller's contributions to science, at Los Alamos it was never possible to separate Teller's science from policy and controversy ...

  19. Dynamic Albedo of Neutrons (DAN) Experiment Onboard NASA's Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Mitrofanov, I. G.; Litvak, M. L.; Varenikov, A. B.; Barmakov, Y. N.; Behar, A.; Bobrovnitsky, Y. I.; Bogolubov, E. P.; Boynton, W. V.; Harshman, K.; Kan, E.; Kozyrev, A. S.; Kuzmin, R. O.; Malakhov, A. V.; Mokrousov, M. I.; Ponomareva, S. N.; Ryzhkov, V. I.; Sanin, A. B.; Smirnov, G. A.; Shvetsov, V. N.; Timoshenko, G. N.; Tomilina, T. M.; Tret'yakov, V. I.; Vostrukhin, A. A.

    2012-09-01

    The description of Dynamic Albedo of Neutrons (DAN) experiment is presented, as a part of the NASA's Mars Science Laboratory mission onboard the mars rover Curiosity. The instrument DAN includes Pulsing Neutron Generator (PNG) producing pulses of 14.1 MeV neutrons for irradiation of subsurface material below the rover, and Detectors and Electronics (DE) unit, which operates the instrument itself and measures the die-away time profiles of epithermal and thermal neutrons following each neutron pulse. It is shown that the DAN investigation will measure a content of hydrogen along the path of the MSL rover, and it will also provide information about a depth distribution of hydrogen at 10-20 regions selected for the detailed studies and sampling analysis.

  20. Immersive Visual Analytics for Transformative Neutron Scattering Science

    SciTech Connect

    Steed, Chad A; Daniel, Jamison R; Drouhard, Margaret; Hahn, Steven E; Proffen, Thomas E

    2016-01-01

    The ORNL Spallation Neutron Source (SNS) provides the most intense pulsed neutron beams in the world for scientific research and development across a broad range of disciplines. SNS experiments produce large volumes of complex data that are analyzed by scientists with varying degrees of experience using 3D visualization and analysis systems. However, it is notoriously difficult to achieve proficiency with 3D visualizations. Because 3D representations are key to understanding the neutron scattering data, scientists are unable to analyze their data in a timely fashion resulting in inefficient use of the limited and expensive SNS beam time. We believe a more intuitive interface for exploring neutron scattering data can be created by combining immersive virtual reality technology with high performance data analytics and human interaction. In this paper, we present our initial investigations of immersive visualization concepts as well as our vision for an immersive visual analytics framework that could lower the barriers to 3D exploratory data analysis of neutron scattering data at the SNS.

  1. Los Alamos National Laboratory

    SciTech Connect

    Dogliani, Harold O

    2011-01-19

    The purpose of the briefing is to describe general laboratory technical capabilities to be used for various groups such as military cadets or university faculty/students and post docs to recruit into a variety of Los Alamos programs. Discussed are: (1) development and application of high leverage science to enable effeictive, predictable and reliability outcomes; (2) deter, detect, characterize, reverse and prevent the proliferation of weapons of mass destruction and their use by adversaries and terrorists; (3) modeling and simulation to define complex processes, predict outcomes, and develop effective prevention, response, and remediation strategies; (4) energetic materials and hydrodynamic testing to develop materials for precise delivery of focused energy; (5) materials cience focused on fundamental understanding of materials behaviors, their quantum-molecular properties, and their dynamic responses, and (6) bio-science to rapidly detect and characterize pathogens, to develop vaccines and prophylactic remedies, and to develop attribution forensics.

  2. MCNP modeling of a neutron generator and its shielding at Missouri University of Science and Technology

    NASA Astrophysics Data System (ADS)

    Sharma, Manish K.; Alajo, Ayodeji Babatunde; Liu, Xin

    2014-12-01

    The shielding of a neutron generator producing fast neutrons should be sufficient to limit the dose rates to the prescribed values. A deuterium-deuterium neutron generator has been installed in the Nuclear Engineering Department at Missouri University of Science and Technology (Missouri S&T). The generator produces fast neutrons with an approximate energy of 2.5 MeV. The generator is currently shielded with different materials like lead, high-density polyethylene, and borated polyethylene. An MCNP transport simulation has been performed to estimate the dose rates at various places in and around the facility. The simulations incorporated the geometric and composition information of these shielding materials to determine neutron and photon dose rates at three central planes passing through the neutron source. Neutron and photon dose rate contour plots at these planes were provided using a MATLAB program. Furthermore, the maximum dose rates in the vicinity of the facility were used to estimate the annual limit for the generator's hours of operation. A successful operation of this generator will provide a convenient neutron source for basic and applied research at the Nuclear Engineering Department of Missouri S&T.

  3. Audit Report, "Fire Protection Deficiencies at Los Alamos National Laboratory"

    SciTech Connect

    2009-06-01

    ; and, (2) A substantial portion of the uncorrected deficiencies, 86 (49 percent) were considered by the walk-down teams to be significant enough to warrant compensatory actions until the deficiency was corrected or was tracked to closure through implementation of corrective actions. Further, we found that 32 of the significant deficiencies had been closed by the previous Los Alamos contractor, prior to LANS assuming responsibility for operation of the Laboratory, even though the deficiencies had not been corrected. A fire protection expert provided technical support during the audit. As an example of uncorrected problems, LANS had not resolved, by performing periodic tests, a deficiency identified in 2006 regarding a kitchen hood fire suppression system in a facility located within the Los Alamos Neutron Science Center. Such systems are required to be tested twice a year by the National Fire Protection Association standard, a standard that had been adopted by Department of Energy under DOE Order 420.1B. Yet, in 2006, the LANS walk-down team recognized that this system had not been inspected since May 2004 and noted that deficient suppression systems could result in significantly high levels of property damage and loss. After we brought this issue to management's attention on February 6, 2009, LANS officials stated that the Laboratory would correct this deficiency. As with the problems involving the fire suppression system, we observed that LANS had not always corrected life safety deficiencies involving building exits at one of its primary facilities. This included providing a secondary emergency exit for a building with occupants on multiple floor levels. LANS had removed personnel from the third floor and improved the sprinkler system of the facility, but it had still not provided a secondary exit for personnel on the second floor by the time we completed our review. NNSA has since stated that this fire protection issue will be completely addressed by relocating

  4. Active Neutron Shielding R&D for Dark Matter Searches

    NASA Astrophysics Data System (ADS)

    Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter; Dmtpc Collaboration

    2011-04-01

    Neutrons are a dangerous background to direct dark matter detection searches because they can mimic exactly the signal signature. For this reason, it is desirable to measure the neutron flux directly at underground sites where dark matter experiments are active. We have developed a liquid scintillator-based neutron detector for this purpose, which is currently underground and taking data at the Waste Isolation Pilot Plant (WIPP) in NM. Before being commissioned underground, the response of this detector to neutrons with kinetic energies from 50 MeV to 800 MeV was determined in a beam test at the Los Alamos Neutron Science Center (LANSCE) in NM. The goal of this R&D is to (i) demonstrate the feasibility of a large scale active and passive neutron shield for dark matter searches and (ii) to measure the neutron energy spectrum underground at WIPP above 50 MeV neutron kinetic energies.

  5. The Art of Neutron Spin Flipping

    NASA Astrophysics Data System (ADS)

    Lieffers, Justin; Holley, Adam; Snow, W. M.

    2014-09-01

    Low energy precision measurements complement high energy collider results in the search for physics beyond the Standard Model. Neutron spin rotation is a sensitive technique to search for possible exotic velocity and spin-dependent interactions involving the neutron from the exchange of light (~ meV) spin 1 bosons. We plan to conduct such searches using beams of cold neutrons at the Los Alamos Neutron Science Center (LANSCE) and the National Institute of Standards and Technology (NIST). To change the spin state of the neutrons in the apparatus we have developed an Adiabatic Fast Passage (AFP) neutron spin flipper. I will present the mechanical design, static and RF magnetic field modeling and measurements, and spin flip efficiency optimization of the constructed device. I would like to acknowledge the NSF REU program (NSF-REU grant PHY-1156540) and the Indiana University nuclear physics group (NSF grant PHY-1306942) for this opportunity.

  6. Active Neutron and Gamma-Ray Instrumentation for In Situ Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; Floyd, A.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    We describe the development of an instrument capable of detailed in situ bulk geochemical analysis of the surface of planets, moons, asteroids, and comets. This instrument technology uses a pulsed neutron generator to excite the solid materials of a planet and measures the resulting neutron and gamma-ray emission with its detector system. These time-resolved neutron and gamma-ray data provide detailed information about the bulk elemental composition, chemical context, and density distribution of the soil within 50 cm of the surface. While active neutron scattering and neutron-induced gamma-ray techniques have been used extensively for terrestrial nuclear well logging applications, our goal is to apply these techniques to surface instruments for use on any solid solar system body. As described, experiments at NASA Goddard Space Flight Center use a prototype neutron-induced gamma-ray instrument and the resulting data presented show the promise of this technique for becoming a versatile, robust, workhorse technology for planetary science, and exploration of any of the solid bodies in the solar system. The detection of neutrons at the surface also provides useful information about the material. This paper focuses on the data provided by the gamma-ray detector.

  7. Remote Job Testing for the Neutron Science TeraGrid Gateway

    SciTech Connect

    Lynch, Vickie E; Cobb, John W; Miller, Stephen D; Reuter, Michael A; Smith, Bradford C

    2009-01-01

    Remote job execution gives neutron science facilities access to high performance computing such as the TeraGrid. A scientific community can use community software with a community certificate and account through a common interface of a portal. Results show this approach is successful, but with more testing and problem solving, we expect remote job executions to become more reliable.

  8. Design of a target and moderator at the Los Alamos Spallation Radiation Effects Facility (LASREF) as a neutron source for fusion reactor materials development

    SciTech Connect

    Ferguson, P.D.; Mueller, G.E.; Sommer, W.F.; Farnum, E.H.

    1993-10-01

    The LASREF facility is located in the beam stop area at LAMPF. The neutron spectrum is fission-like with the addition of a 3% to 5% component with E > 20 MeV. The present study evaluates the limits on geometry and material selection that will maximize the neutron flux. MCNP and LAHET were used to predict the neutron flux and energy spectrum for a variety of geometries. The problem considers 760 MeV protons incident on tungsten. The resulting neutrons are multiplied in uranium through (n,xn) reactions. Calculations show that a neutron flux greater than 10{sup 19} n/m{sup 2}/s is achievable. The helium to dpa ratio and the transmutation product generation are calculated. These results are compared to expectations for the proposed DEMO fusion reactor and to FFTF.

  9. Los Alamos waste drum shufflers users manual

    SciTech Connect

    Rinard, P.M.; Adams, E.L.; Painter, J.

    1993-08-24

    This user manual describes the Los Alamos waste drum shufflers. The primary purpose of the instruments is to assay the mass of {sup 235}U (or other fissile materials) in drums of assorted waste. It can perform passive assays for isotopes that spontaneously emit neutrons or active assays using the shuffler technique as described on this manual.

  10. Materials for spallation neutron sources

    SciTech Connect

    Sommer, W.F.; Daemen, L.L.

    1996-03-01

    The Workshop on Materials for Spallation Neutron Sources at the Los Alamos Neutron Science Center, February 6 to 10, 1995, gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss areas in which work is needed, successful designs and use of materials, and opportunities for further studies. During the first day of the workshop, speakers presented overviews of current spallation neutron sources. During the next 3 days, seven panels allowed speakers to present information on a variety of topics ranging from experimental and theoretical considerations on radiation damage to materials safety issues. An attempt was made to identify specific problems that require attention within the context of spallation neutron sources. This proceedings is a collection of summaries from the overview sessions and the panel presentations.

  11. Advanced neutron irradiation system using Texas A&M University Nuclear Science Center Reactor

    NASA Astrophysics Data System (ADS)

    Jang, Si Young

    A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast neutrons with the alloy. It is possible, therefore, by changing the alloy thickness, to produce distinctly different dose weighted neutron spectra inside the exposure cave of the FNIS. The calculated neutron spectra showed close agreement with the results of activation foil measurements, unfolded by SAND-II close to the cell window. However, there was a considerable less agreement for locations far away from the cell window. Even though the magnitude of values such as neutron flux and tissue kerma rates in air differed, the weighted average neutron energies showed close agreement between the MCNP and SAND-II since the normalized neutron spectra were in a good agreement each other. A paired ion chamber system was constructed, one with a tissue equivalent plastic (A-150) and propane gas for total dose monitoring, and another with graphite and argon for photon dose monitoring. Using the pair of detectors, the neutron to gamma ratio can be inferred. With the 20 cm-thick FNIS, the absorbed dose rates of neutrons measured with the paired ion chamber method and calculated with the SAND-II results were 13.7 +/- 0.02 Gy/min and 15.5 Gy/min, respectively. The absorbed dose rate of photons and the gamma contribution to total dose were 6.7 x 10

  12. Polarised nuclei for neutron science: recent applications and perspectives

    NASA Astrophysics Data System (ADS)

    Glättli, Hans

    2004-08-01

    Neutron scattering on nuclei is spin dependent, particularly strongly for 1H. The means to achieve large nuclear polarisations and its use for structure analysis or as spin-handling device are reviewed. High resolution (diffraction) as well as low resolution (SANS) measurements can benefit from polarised nuclei by changing selectively the form factors of Bragg reflections or the contrasts (the scattering length density profiles) in SANS. The internal structure of ribosomes and the conformation of polymers in solution have been investigated by this method. A numerical simulation is presented to show the influence of steady-state polarisation of protons on the scattering from a protein-ARN model complex. In addition, a more recent technique, time-resolved SANS is described. It makes use of spatial polarisation gradients created around paramagnetic centres at the onset of nuclear polarisation. Such polarisation domains can enhance considerably the scattering amplitude of free radicals and thus contribute to determine their positions inside a complex protein. Examples of possible future experiments are proposed which combine simultaneously the selectivity of solid-state NMR techniques and neutron scattering.

  13. The sciences and applications of the Electron LINAC-driven neutron source in Argentina

    NASA Astrophysics Data System (ADS)

    Granada, J. R.; Mayer, R. E.; Dawidowski, J.; Santisteban, J. R.; Cantargi, F.; Blostein, J. J.; Rodríguez Palomino, L. A.; Tartaglione, A.

    2016-06-01

    The Neutron Physics group at Centro Atómico Bariloche (CNEA, Argentina) has evolved for more than forty five years around a small 25MeV linear electron accelerator. It constitutes our compact accelerator-driven neutron source (CANS), which is dedicated to the use and development of neutronic methods to tackle problems of basic sciences and technological applications. Its historical first commitment has been the determination of the total cross sections of materials as a function of neutron energy by means of transmission experiments for thermal and sub-thermal neutrons. This also allowed testing theoretical models for the generation of scattering kernels and cross sections. Through the years, our interests moved from classic pulsed neutron diffraction, which included the development of high-precision methods for the determination of very low hydrogen content in metals, towards deep inelastic neutron scattering (DINS), a powerful tool for the determination of atomic momentum distribution in condensed matter. More recently non-intrusive techniques aimed at the scanning of large cargo containers have started to be developed with our CANS, testing the capacity and limitations to detect special nuclear material and dangerous substances. Also, the ever-present "bremsstrahlung" radiation has been recognized and tested as a useful complement to instrumental neutron activation, as it permits to detect other nuclear species through high-energy photon activation. The facility is also used for graduate and undergraduate students' experimental work within the frame of Instituto Balseiro Physics and Nuclear Engineering courses of study, and also MSc and PhD theses work.

  14. High energy neutron radiography

    SciTech Connect

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-06-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos.

  15. Actinide Studies with Ultracold Neutrons

    NASA Astrophysics Data System (ADS)

    Broussard, Leah

    2014-03-01

    Understanding the effects of sputtering due to nuclear fission is crucial to the nuclear industry and has wide-reaching applications, including nuclear energy, space science, and national defense. A new program at the Los Alamos Neutron Science Center uses ultracold neutrons (UCN) to induce fission in actinides such as uranium and plutonium. UCN are an ideal tool for finely controlling induced fission as a function of depth in an actinide sample. The mechanism for fission-induced surface damage is not well understood, especially regarding the effect of a surface oxide layer. We will discuss our experimental strategy for studies of UCN-induced fission and the ejected material, and present preliminary data from enriched and depleted uranium. We gratefully acknowledge the support of the G. T. Seaborg Institute for Transactinium Science and the U.S. Department of Energy through the LANL/LDRD Program for this work.

  16. Neutron chopper development at LANSCE

    SciTech Connect

    Nutter, M.; Lewis, L.; Tepper, S.; Silver, R.N.; Heffner, R.H.

    1985-01-01

    Progress is reported on neutron chopper systems for the Los Alamos Neutron Scattering Center pulsed spallation neutron source. This includes the development of 600+ Hz active magnetic bearing neutron chopper and a high speed control system designed to operate with the Proton Storage Ring to phase the chopper to the neutron source. 5 refs., 3 figs.

  17. Neutron capture measurement on {sup 173}Lu at LANSCE with DANCE detector

    SciTech Connect

    Theroine, C.; Ebran, A.; Meot, V.; Roig, O.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Nortier, F. M.; O'Donnell, J. M.; Rundberg, R. S.; Taylor, W. A.; Ullmann, J. L.; Viera, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2013-06-10

    The (n,{gamma}) cross section on the unstable {sup 173}Lu(t{sub 1/2} = 1.37y) has been measured from thermal energy up to 200 eV at Los Alamos Neutron Science Center (LANSCE) with The Detector for Advanced Neutron Capture Experiements (DANCE). The main aim of this study is to validate and optimize reaction models for unstable nucleus. A preliminary capture yield will be presented in this paper.

  18. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  19. Measurements of the neutron spectrum in transit to Mars on the Mars Science Laboratory.

    PubMed

    Köhler, J; Ehresmann, B; Zeitlin, C; Wimmer-Schweingruber, R F; Hassler, D M; Reitz, G; Brinza, D E; Appel, J; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Lohf, H; Martin, C; Posner, A; Rafkin, S

    2015-04-01

    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011. Although designed for measuring the radiation on the surface of Mars, the Radiation Assessment Detector (RAD) measured the radiation environment inside the spacecraft during most of the 253-day, 560-million-kilometer cruise to Mars. An important factor for determining the biological impact of the radiation environment inside the spacecraft is the specific contribution of neutrons with their high biological effectiveness. We apply an inversion method (based on a maximum-likelihood estimation) to calculate the neutron and gamma spectra from the RAD neutral particle measurements. The measured neutron spectrum (12-436 MeV) translates into a radiation dose rate of 3.8±1.2 μGy/day and a dose equivalent of 19±5 μSv/day. Extrapolating the measured spectrum (0.1-1000 MeV), we find that the total neutron-induced dose rate is 6±2 μGy/day and the dose equivalent rate is 30±10 μSv/day. For a 360 day round-trip from Earth to Mars with comparable shielding, this translates into a neutron induced dose equivalent of about 11±4 mSv. PMID:26177845

  20. Measurements of the neutron spectrum in transit to Mars on the Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Köhler, J.; Ehresmann, B.; Zeitlin, C.; Wimmer-Schweingruber, R. F.; Hassler, D. M.; Reitz, G.; Brinza, D. E.; Appel, J.; Böttcher, S.; Böhm, E.; Burmeister, S.; Guo, J.; Lohf, H.; Martin, C.; Posner, A.; Rafkin, S.

    2015-04-01

    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011. Although designed for measuring the radiation on the surface of Mars, the Radiation Assessment Detector (RAD) measured the radiation environment inside the spacecraft during most of the 253-day, 560-million-kilometer cruise to Mars. An important factor for determining the biological impact of the radiation environment inside the spacecraft is the specific contribution of neutrons with their high biological effectiveness. We apply an inversion method (based on a maximum-likelihood estimation) to calculate the neutron and gamma spectra from the RAD neutral particle measurements. The measured neutron spectrum (12-436 MeV) translates into a radiation dose rate of 3.8 ± 1.2 μGy /day and a dose equivalent of 19 ± 5 μSv /day. Extrapolating the measured spectrum (0.1-1000 MeV), we find that the total neutron-induced dose rate is 6 ± 2 μGy /day and the dose equivalent rate is 30 ± 10 μSv /day. For a 360 day round-trip from Earth to Mars with comparable shielding, this translates into a neutron induced dose equivalent of about 11 ± 4 mSv.

  1. A Kinesthetic Learning Approach to Earth Science for 3rd and 4th Grade Students on the Pajarito Plateau, Los Alamos, NM

    NASA Astrophysics Data System (ADS)

    Wershow, H. N.; Green, M.; Stocker, A.; Staires, D.

    2010-12-01

    Current efforts towards Earth Science literacy in New Mexico are guided by the New Mexico Science Benchmarks [1]. We are geoscience professionals in Los Alamos, NM who believe there is an important role for non-traditional educators utilizing innovative teaching methods. We propose to further Earth Science literacy for local 3rd and 4th grade students using a kinesthetic learning approach, with the goal of fostering an interactive relationship between the students and their geologic environment. We will be working in partnership with the Pajarito Environmental Education Center (PEEC), which teaches the natural heritage of the Pajarito Plateau to 3rd and 4th grade students from the surrounding area, as well as the Family YMCA’s Adventure Programs Director. The Pajarito Plateau provides a remarkable geologic classroom because minimal structural features complicate the stratigraphy and dramatic volcanic and erosional processes are plainly on display and easily accessible. Our methodology consists of two approaches. First, we will build an interpretive display of the local geology at PEEC that will highlight prominent rock formations and geologic processes seen on a daily basis. It will include a simplified stratigraphic section with field specimens and a map linked to each specimen’s location to encourage further exploration. Second, we will develop and implement a kinesthetic curriculum for an exploratory field class. Active engagement with geologic phenomena will take place in many forms, such as a scavenger hunt for precipitated crystals in the vesicles of basalt flows and a search for progressively smaller rhyodacite clasts scattered along an actively eroding canyon. We believe students will be more receptive to origin explanations when they possess a piece of the story. Students will be provided with field books to make drawings of geologic features. This will encourage independent assessment of phenomena and introduce the skill of scientific observation. We

  2. Science-based stockpile stewardship at LANSCE

    SciTech Connect

    Browne, J.

    1995-10-01

    Let me tell you a little about the Los Alamos Neutron Science Center (LANSCE) and how some of the examples you heard about from Sig Hecker and John Immele fit together in this view of a different world in the future where defense, basic and industrial research overlap. I am going to talk about science-based stockpile stewardship at LANSCE; the accelerator production of tritium (APT), which I think has a real bearing on the neutron road map; the world-class neutron science user facility, for which I will provide some examples so you can see the connection with defense science; and lastly, testing concepts for a high-power spallation neutron target and waste transmutation.

  3. Comparison of beam transport simulations to measurements at the Los Alamos Proton Storage Ring

    SciTech Connect

    Wilkinson, C.; Neri, F.; Fitzgerald, D.H.; Blind, B.; Macek, R.; Plum, M.; Sander, O.; Thiessen, H.A.

    1997-10-01

    The ability to model and simulate beam behavior in the Proton Storage Ring (PSR) of the Los Alamos Neutron Science Center (LANSCE) is an important diagnostic and predictive tool. This paper gives the results of an effort to model the ring apertures and lattice and use beam simulation programs to track the beam. The results are then compared to measured activation levels from beam loss in the ring. The success of the method determines its usefulness in evaluating the effects of planned upgrades to the Proton Storage Ring.

  4. Determination of the axial-vector weak coupling constant with ultracold neutrons.

    PubMed

    Liu, J; Mendenhall, M P; Holley, A T; Back, H O; Bowles, T J; Broussard, L J; Carr, R; Clayton, S; Currie, S; Filippone, B W; García, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Hona, B; Ito, T M; Liu, C-Y; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Morris, C L; Pattie, R W; Pérez Galván, A; Pitt, M L; Plaster, B; Ramsey, J C; Rios, R; Russell, R; Saunders, A; Seestrom, S J; Sondheim, W E; Tatar, E; Vogelaar, R B; VornDick, B; Wrede, C; Yan, H; Young, A R

    2010-10-29

    A precise measurement of the neutron decay β asymmetry A₀ has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A₀ = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}. PMID:21231098

  5. Fission neutron spectra measurements at LANSCE - status and plans

    SciTech Connect

    Haight, Robert C; Noda, Shusaku; Nelson, Ronald O; O' Donnell, John M; Devlin, Matt; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Laurent, Benoit; Belier, Gilbert; Becker, John A; Wu, Ching - Yen

    2009-01-01

    A program to measure fission neutron spectra from neutron-induced fission of actinides is underway at the Los Alamos Neutron Science Center (LANSCE) in a collaboration among the CEA laboratory at Bruyeres-le-Chatel, Lawrence Livermore National Laboratory and Los Alamos National Laboratory. The spallation source of fast neutrons at LANSCE is used to provide incident neutron energies from less than 1 MeV to 100 MeV or higher. The fission events take place in a gas-ionization fission chamber, and the time of flight from the neutron source to that chamber gives the energy of the incident neutron. Outgoing neutrons are detected by an array of organic liquid scintillator neutron detectors, and their energies are deduced from the time of flight from the fission chamber to the neutron detector. Measurements have been made of the fission neutrons from fission of {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu. The range of outgoing energies measured so far is from 1 MeV to approximately 8 MeV. These partial spectra and average fission neutron energies are compared with evaluated data and with models of fission neutron emission. Results to date will be presented and a discussion of uncertainties will be given in this presentation. Future plans are to make significant improvements in the fission chambers, neutron detectors, signal processing, data acquisition and the experimental environment to provide high fidelity data including mea urements of fission neutrons below 1 MeV and improvements in the data above 8 MeV.

  6. Los Alamos science, Number 14

    SciTech Connect

    Not Available

    1986-01-01

    Nine authored articles are included covering: natural heat engine, photoconductivity, the Caribbean Basin, energy in Central America, peat, geothermal energy, and the MANIAC computer. Separate abstracts were prepared for the articles. (DLC)

  7. Status of Monte Carlo at Los Alamos

    SciTech Connect

    Thompson, W.L.; Cashwell, E.D.

    1980-01-01

    At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time.

  8. Materials science and engineering

    SciTech Connect

    Holden, T.M.

    1995-10-01

    The science-based stockpile stewardship program emphasizes a better understanding of how complex components function through advanced computer calculations. Many of the problem areas are in the behavior of materials making up the equipment. The Los Alamos Neutron Science Center (LANSCE) can contribute to solving these problems by providing diagnostic tools to examine parts noninvasively and by providing the experimental tools to understand material behavior in terms of both the atomic structure and the microstructure. Advanced computer codes need experimental information on material behavior in response to stress, temperature, and pressure as input, and they need benchmarking experiments to test the model predictions for the finished part.

  9. Los Alamos National Laboratory.

    ERIC Educational Resources Information Center

    Hammel, Edward F., Jr.

    1982-01-01

    Current and post World War II scientific research at the Los Alamos National Laboratory (New Mexico) is discussed. The operation of the laboratory, the Los Alamos consultant program, and continuation education, and continuing education activities at the laboratory are also discussed. (JN)

  10. Neutron-induced reaction studies at FIGARO using a spallation source

    NASA Astrophysics Data System (ADS)

    Rochman, D.; Haight, R. C.; O'Donnell, J. M.; Devlin, M.; Ethvignot, T.; Granier, T.

    2004-05-01

    A description is given of the new flexible facility Fast Neutron-Induced Gamma-Ray Observer (FIGARO) at the Los Alamos Neutron Science Center. FIGARO is designed to study fast-neutron-induced reactions that result in the emission of γ rays and neutrons, using the white neutron beam of the Weapons Neutron Research Facility. The emitted neutrons and γ rays are detected by several liquid scintillators and one high-resolution germanium or one barium-fluoride detector, respectively. As an example, the inelastic neutron scattering on Si from 4 to 20 MeV is presented and the results are compared with predictions of the nuclear model calculations performed with the codes GNASH and EMPIRE II.

  11. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  12. Macromolecular neutron crystallography at the Protein Crystallography Station (PCS)

    PubMed Central

    Kovalevsky, Andrey; Fisher, Zoe; Johnson, Hannah; Mustyakimov, Marat; Waltman, Mary Jo; Langan, Paul

    2010-01-01

    The Protein Crystallography Station (PCS) at Los Alamos Neutron Science Center is a high-performance beamline that forms the core of a capability for neutron macromolecular structure and function determination. Neutron diffraction is a powerful technique for locating H atoms and can therefore provide unique information about how biological macro­molecules function and interact with each other and smaller molecules. Users of the PCS have access to neutron beam time, deuteration facilities, the expression of proteins and the synthesis of substrates with stable isotopes and also support for data reduction and structure analysis. The beamline exploits the pulsed nature of spallation neutrons and a large electronic detector in order to collect wavelength-resolved Laue patterns using all available neutrons in the white beam. The PCS user facility is described and highlights from the user program are presented. PMID:21041938

  13. Filtered fast neutron irradiation system using Texas A&M University Nuclear Science Center Reactor

    NASA Astrophysics Data System (ADS)

    Jang, S. Y.; Kim, C. H.; Reece, W. D.; Braby, L. A.

    2004-09-01

    A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). For a realistic modeling of the NSCR, the irradiation cell, and the FNIS, this study used the Monte Carlo N-Particle (MCNP) code and a set of high-temperature ENDF/B-VI continuous neutron cross-section data. Sensitivity analysis was performed to find the characteristics of the FNIS as a function of the thickness of the lead-bismuth alloy. A paired ion chamber system was constructed with a tissue-equivalent plastic (A-150) and propane gas for total dose monitoring and with graphite and argon for gamma dose monitoring. This study, in addition, tested the Monte Carlo modeling of the FNIS system, as well as the performance of the system by comparing the calculated results with experimental measurements using activation foils and paired ion chambers.

  14. Active Neutron and Gamma Ray Instrumentation for In Situ Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    The Pulsed Neutron Generator-Gamma Ray And Neutron Detectors (PNG-GRAND) experiment is an innovative application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA-GSFC) is to bring the PNG-GRAND instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Menus, asteroids, comets and the satellites of the outer planets. Gamma-Ray Spectrometers (GRS) have been incorporated into numerous orbital planetary science missions and, especially its the case of the Mars Odyssey GRS, have contributed detailed maps of the elemental composition over the entire surface of Mars. However, orbital gamma ray measurements have low spatial sensitivity (100's of km) due to their low surface emission rates from cosmic rays and subsequent need to be averaged over large surface areas. PNG-GRAND overcomes this impediment by incorporating a powerful neutron excitation source that permits high sensitivity surface and subsurface measurements of bulk elemental compositions. PNG-GRAND combines a pulsed neutron generator (PNG) with gamma ray and neutron detectors to produce a landed instrument to determine subsurface elemental composition without needing to drill into a planet's surface a great advantage in mission design. We are currently testing PNG-GRAND prototypes at a unique outdoor neutron instrumentation test facility recently constructed at NASA/GSFC that consists of a 2 m x 2 in x 1 m granite structure placed outdoors in an empty field. Because an independent trace elemental analysis has been performed on the material, this granite sample is a known standard with which to compare both Monte Carlo simulations and our experimentally measured elemental composition data. We will present data from operating PNG-GRAND in various experimental configurations on a

  15. A feasibility study for a one-megawatt pulsed spallation source at Los Alamos National Laboratory

    SciTech Connect

    Pynn, R.

    1994-07-01

    Over the past two decades, high-intensity proton accelerators have been designed and developed to support nuclear physics research and defense applications. This technology has now matured to the point where it can support simultaneous and cost-effective exploitation of a number of important areas of both basic and applied science. Examples include neutron scattering, the production of radioisotopes, tests of technologies to transmute nuclear waste, radiation damage studies, nuclear physics, and muon spin research. As part of a larger program involving these and other areas, a team at Los Alamos National Laboratory has undertaken a feasibility study for a 1-MW pulsed spallation neutron source (PSS) based on the use of an 800-MeV proton linac and an accumulator ring. In January 1994, the feasibility study was reviewed by a large, international group of experts in the design of accelerators and neutron spallation targets. This group confirmed the viability of the proposed neutron source. In this paper, I describe the approach Los Alamos has taken to the feasibility study, which has involved a synergistic application of the Laboratory`s expertise in nuclear science and technology, computation, and particle-beam technologies. Several examples of problems resolved by the study are described, including chopping of low-energy proton beam, interactions between H{sup {minus}} particles and the stripper foil used to produce protons for injection into an accumulator ring, and the inclusion of engineering realities into the design of a neutron production target. These examples are chosen to illustrate the breadth of the expertise that has been brought to bear on the feasibility study and to demonstrate that there are real R&D issues that need to be resolved before a next-generation spoliation source can be built.

  16. Status of the Los Alamos Anger camera

    SciTech Connect

    Seeger, P.A.; Nutter, M.J.

    1985-01-01

    Results of preliminary tests of the neutron Anger camera being developed at Los Alamos are presented. This detector uses a unique encoding scheme involving parellel processing of multiple receptive fields. Design goals have not yet been met, but the results are very encouraging and improvements in the test procedures are expected to show that the detector will be ready for use on a small-angle scattering instrument next year. 3 refs., 4 figs.

  17. Monte Carlo simulations for high-rate fast neutron flux measurements made at the RAON neutron science facility by using MICROMEGAS

    NASA Astrophysics Data System (ADS)

    Hwang, Dae Hee; Hong, Ser Gi; Kim, Jae Cheon; Kim, Gi Dong; Kim, Yong Kyun

    2015-10-01

    RAON is a Korean heavy-ion accelerator complex that is planned to be built by 2021. Deuterons (53 MeV) and protons (88 MeV) accelerated by using a low-energy driver linac (SCL1) are delivered to the neutron production target in the Neutron Science Facility (NSF) to produce high-energy neutrons in the interval from 1 to 88 MeV with high fluxes of the order of 1012 n/cm2-sec. The repetition rate of the neutron beam ranges from 1 kHz to 1 MHz, and the maximum beam current is ~12 μA at 1 MHz. The beam width is 1 ~ 2 ns. The high-energy and high-rate fast neutrons are used to estimate accurate neutron-induced cross sections for various nuclides at the NSF. A MICROMEGAS (MICRO Mesh Gaseous Structure), which is a gaseous detector initially developed for tracking in high-rate, high-energy physics experiments, is tentatively being considered as a neutron beam monitor. It can be used to measure both the energy distribution and the flux of the neutron beam. In this study, a MICROMEGAS detector for installation at the NSF was designed and investigated. 6Li, 10B, 235U and 238U targets are being considered as neutron/charged particle converters. For the low-energy region, 6Li(n,α)t and 10B(n,α)7Li are used in the energy range from thermal to 1 MeV. 235U(n,f) and 238U(n,f) reactions are used for high-energy region up to 90 MeV. All calculations are performed by using the GEANT4 toolkit.

  18. HEND Maps of Fast Neutrons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations by NASA's 2001 Mars Odyssey spacecraft show a global view of Mars in high-energy, or fast, neutrons. These maps are based on data acquired by the high-energy neutron detector, one of the instruments in the gamma ray spectrometer suite. Fast neutrons, like epithermal neutrons, are sensitive to the presence of hydrogen. Unlike epithermal neutrons, however, they are not affected by the presence of carbon dioxide, which at the time of these observations covered the north polar area as 'dry ice' frost. The low flux of fast neutrons (blue and purple colors) in the north polar region suggests an abundance of hydrogen in the soil comparable to that determined in the south from the flux of epithermal neutrons. These observations were acquired during the first two months of mapping operations. Contours of topography are superimposed on these maps for geographic reference.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Studies of Neutron-Induced Fission of 235U, 238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Duke, Dana; TKE Team

    2014-09-01

    A Frisch-gridded ionization chamber and the double energy (2E) analysis method were used to study mass yield distributions and average total kinetic energy (TKE) release from neutron-induced fission of 235U, 238U, and 239Pu. Despite decades of fission research, little or no TKE data exist for high incident neutron energies. Additional average TKE information at incident neutron energies relevant to defense- and energy-related applications will provide a valuable observable for benchmarking simulations. The data can also be used as inputs in theoretical fission models. The Los Alamos Neutron Science Center-Weapons Neutron Research (LANSCE - WNR) provides a neutron beam from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on 238U, 235U, and 239Pu will be presented. LA-UR-14-24921.

  20. Spin distribution in neutron induced preequilibrium reactions

    SciTech Connect

    Dashdorj, D; Kawano, T; Chadwick, M; Devlin, M; Fotiades, N; Nelson, R O; Mitchell, G E; Garrett, P E; Agvaanluvsan, U; Becker, J A; Bernstein, L A; Macri, R; Younes, W

    2005-10-04

    The preequilibrium reaction mechanism makes an important contribution to neutron-induced reactions above E{sub n} {approx} 10 MeV. The preequilibrium process has been studied exclusively via the characteristic high energy neutrons produced at bombarding energies greater than 10 MeV. They are expanding the study of the preequilibrium reaction mechanism through {gamma}-ray spectroscopy. Cross-section measurements were made of prompt {gamma}-ray production as a function of incident neutron energy (E{sub n} = 1 to 250 MeV) on a {sup 48}Ti sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Residual state population was predicted using the GNASH reaction code, enhanced for preequilibrium. The preequilibrium reaction spin distribution was calculated using the quantum mechanical theory of Feshback, Kerman, and Koonin (FKK). The multistep direct part of the FKK theory was calculated for a one-step process. The FKK preequilibrium spin distribution was incorporated into the GNASH calculations and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without preequilibrium effects is significant.

  1. HEND Maps of Epithermal Neutrons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations by NASA's 2001 Mars Odyssey spacecraft show a global view of Mars in intermediate-energy, or epithermal, neutrons. These maps are based on data acquired by the high-energy neutron detector, one of the instruments in the gamma ray spectrometer suite. Soil enriched by hydrogen is indicated by the purple and deep blue colors on the maps, which show a low intensity of epithermal neutrons. Progressively smaller amounts of hydrogen are shown in the colors light blue, green, yellow and red. Hydrogen in the far north is hidden at this time beneath a layer of carbon dioxide frost (dry ice). These observations were acquired during the first two months of mapping operations. Contours of topography are superimposed on these maps for geographic reference.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Neutron Resonance Spin Determination Using Multi-Segmented Detector DANCE

    SciTech Connect

    Baramsai, B.; Mitchell, G. E.; Chyzh, A.; Dashdorj, D.; Walker, C.; Agvaanluvsan, U.; Becvar, F.; Krticka, M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.

    2011-06-01

    A sensitive method to determine the spin of neutron resonances is introduced based on the statistical pattern recognition technique. The new method was used to assign the spins of s-wave resonances in {sup 155}Gd. The experimental neutron capture data for these nuclei were measured with the DANCE (Detector for Advanced Neutron Capture Experiment) calorimeter at the Los Alamos Neutron Science Center. The highly segmented calorimeter provided detailed multiplicity distributions of the capture {gamma}-rays. Using this information, the spins of the neutron capture resonances were determined. With these new spin assignments, level spacings are determined separately for s-wave resonances with J{sup {pi}} = 1{sup -} and 2{sup -}.

  3. 500 MHz neutron detector

    SciTech Connect

    Yen, Yi-Fen; Bowman, J.D.; Matsuda, Y.

    1993-12-01

    A {sup 10}B-loaded scintillation detector was built for neutron transmission measurements at the Los Alamos Neutron Scattering Center. The efficiency of the detector is nearly 100% for neutron energies from 0 to 1 keV. The neutron moderation time in the scintillator is about 250 ns and is energy independent. The detector and data processing system are designed to handle an instantaneous rate as high as 500 MHz. The active area of the detector is 40 cm in diameter.

  4. PREFACE: Buried Interface Sciences with X-rays and Neutrons 2010

    NASA Astrophysics Data System (ADS)

    Sakurai, Kenji

    2011-09-01

    The 2010 summer workshop on buried interface science with x-rays and neutrons was held at Nagoya University, Japan, on 25-27 July 2010. The workshop was organized by the Japan Applied Physics Society, which established a group to develop the research field of studying buried function interfaces with x-rays and neutrons. The workshop was the latest in a series held since 2001; Tsukuba (December 2001), Niigata (September 2002), Nagoya (July 2003), Tsukuba (July 2004), Saitama (March 2005), Yokohama (July 2006), Kusatsu (August 2006), Tokyo (December 2006), Sendai (July 2007), Sapporo (September 2007), Tokyo (December 2007), Tokyo-Akihabara (July 2009) and Hiratsuka (March 2010). The 2010 summer workshop had 64 participants and 34 presentations. Interfaces mark the boundaries of different material systems at which many interesting phenomena take place, thus making it extremely important to design, fabricate and analyse the structures of interfaces at both the atomic and macroscopic scale. For many applications, devices are prepared in the form of multi-layered thin films, with the result that interfaces are not exposed but buried under multiple layers. Because of such buried conditions, it is generally not easy to analyse such interfaces. In certain cases, for example, when the thin surface layer is not a solid but a liquid such as water, scientists can observe the atomic arrangement of the liquid-solid interface directly by using a scanning probe microscope, of which the tip is soaked in water. However, it has become clear that the use of a stylus tip positioned extremely close to the interface might change the structure of the water molecules. Therefore it is absolutely crucial to develop non-contact, non-destructive probes for buried interfaces. It is known that analysis using x-rays and neutrons is one of the most powerful tools for exploring near-surface structures including interfaces buried under several layers. In particular, x-ray analysis using 3rd

  5. The experimental program at the WNR neutron source at LAMPF

    SciTech Connect

    Lisowski, P.W.

    1991-01-01

    There are two white neutron sources at Los Alamos National Laboratory which are used in broad scientific program over the energy range from thermal to about seven hundred MeV. Largely because of the increased intensity over such an unprecedented energy range, use of these two facilities for nuclear science research has grown from 36 experimenters in 1987 to 118 in 1990. This paper focuses on research underway or recently completed at the high-energy neutron source of the WNR facility. 18 refs., 6 figs.

  6. An ultra-cold neutron source at the MLNSC

    SciTech Connect

    Bowles, T.J.; Brun, T.; Hill, R.; Morris, C.; Seestrom, S.J.; Crow, L.; Serebrov, A.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors have carried out the research and development of an Ultra-Cold Neutron (UCN) source at the Manuel Lujan Neutron Scattering Center (MLNSC). A first generation source was constructed to test the feasibility of a rotor source. The source performed well with an UCN production rate reasonably consistent with that expected. This source can now provide the basis for further development work directed at using UCN in fundamental physics research as well as possible applications in materials science.

  7. High-energy and thermal-neutron imaging and modeling with an amorphous silicon flat-panel detector.

    PubMed

    Claytor, Thomas N; Taddeucci, Terry N; Hills, Charles R; Summa, Deborah A; Davis, Anthony W; McDonald, Thomas E; Schwab, Mark J

    2004-10-01

    The Los Alamos Neutron Science Center (LANSCE) operates two spallation neutron sources dedicated to research in materials science, condensed-matter physics, and fundamental and applied nuclear physics. Prior to 1995, all thermal neutron radiography at Los Alamos was done on a beam port attached to the Omega West reactor, a small 8MW research reactor used primarily for radioisotope production and prompt and delayed neutron activation analysis. After the closure of this facility, two largely independent radiography development efforts were begun at LANSCE using moderated cold and thermal neutrons from the Target-1 source and high-energy neutrons from the Target-4 source. Investigations with cold and thermal neutrons employed a neutron converter and film, a scintillation screen and CCD camera system, and a new high-resolution amorphous silicon (a-Si) flat-panel detector system. Recent work with high-energy neutrons (En > 1 MeV) has involved storage-phosphor image plates. Some comparison high-energy images were obtained with both image plates and the a-Si panel and showed equivalent image quality for approximately equal exposure times. PMID:15246402

  8. Los Alamos offers Fellowships

    NASA Astrophysics Data System (ADS)

    Los Alamos National Laboratory in New Mexico is calling for applications for postdoctoral appointments and research fellowships. The positions are available in geoscience as well as other scientific disciplines.The laboratory, which is operated by the University of California for the Department of Energy, awards J. Robert Oppenheimer Research Fellowships to scientists that either have or will soon complete doctoral degrees. The appointments are for two years, are renewable for a third year, and carry a stipend of $51,865 per year. Potential applicants should send a resume or employment application and a statement of research goals to Carol M. Rich, Div. 89, Human Resources Development Division, MS P290, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 by mid-November.

  9. Second Einstein Telescope mock data and science challenge: Low frequency binary neutron star data analysis

    NASA Astrophysics Data System (ADS)

    Meacher, Duncan; Cannon, Kipp; Hanna, Chad; Regimbau, Tania; Sathyaprakash, B. S.

    2016-01-01

    The Einstein Telescope is a conceived third-generation gravitational-wave detector that is envisioned to be an order of magnitude more sensitive than advanced LIGO, Virgo, and Kagra, which would be able to detect gravitational-wave signals from the coalescence of compact objects with waveforms starting as low as 1 Hz. With this level of sensitivity, we expect to detect sources at cosmological distances. In this paper we introduce an improved method for the generation of mock data and analyze it with a new low-latency compact binary search pipeline called gstlal. We present the results from this analysis with a focus on low-frequency analysis of binary neutron stars. Despite compact binary coalescence signals lasting hours in the Einstein Telescope sensitivity band when starting at 5 Hz, we show that we are able to discern various overlapping signals from one another. We also determine the detection efficiency for each of the analysis runs conducted and show a proof of concept method for estimating the number signals as a function of redshift. Finally, we show that our ability to recover the signal parameters has improved by an order of magnitude when compared to the results of the first mock data and science challenge. For binary neutron stars we are able to recover the total mass and chirp mass to within 0.5% and 0.05%, respectively.

  10. 196Pt(n,xn yp γ) reactions using spallation neutrons from En=1 to 250 MeV

    NASA Astrophysics Data System (ADS)

    Tavukcu, E.; Bernstein, L. A.; Hauschild, K.; Becker, J. A.; Garrett, P. E.; McGrath, C. A.; McNabb, D. P.; Younes, W.; Chadwick, M. B.; Nelson, R. O.; Johns, G. D.; Mitchell, G. E.

    2001-11-01

    Neutron-induced reactions on 196Pt were studied over the neutron energy range from 1 to 250 MeV. A ``white'' neutron beam was provided by the spallation neutron source of the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The prompt reaction γ rays were measured with the large-scale Compton-suppressed Ge spectrometer GEANIE. The incident neutron energy was determined by the time-of-flight technique. Excitation functions for γ-ray transitions in 184,186,188,190-196Pt and 189,191,193Ir isotopes are compared with enhanced Hauser-Feshbach reaction modeling, as implemented in the reaction code GNASH. Overall, the model predictions agree well with the measured γ-ray yields. Discrepancies appear, however, due to inadequate discrete-level information in the calculations describing the preequilibrium process.

  11. Determination of proton and neutron spectra in the LANSCE spallation irradiation facility

    SciTech Connect

    James, M.R.; Maloy, S.A.; Sommer, W.F.; Fowler, M.M.; Dry, D.; Ferguson, P.D.; Mueller, G.; Corzine, R.K.

    1999-06-01

    Materials samples were recently irradiated in the Los Alamos Radiation Effects Facility (LASREF) at the Los Alamos Neutron Science Center (LANSCE) to provide data for the Accelerator Production of Tritium (APT) project on the effect of irradiation on the mechanical and physical properties of materials. The targets were configured to expose samples to a variety of radiation environments including, high-energy protons, mixed protons and high-energy neutrons, and low-energy neutrons. The samples were irradiated for approximately six months during a ten month period using an 800 MeV proton beam with a circular Gaussian shape of approximately 2{sigma} = 3.0 cm. At the end of this period, the samples were extracted and tested. Activation foils were also extracted that had been placed in proximity to the materials samples. These were used to quantify the fluences in various locations.

  12. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    SciTech Connect

    Haight, Robert C; Devlin, Matthew J; Nelson, Ronald O; O' Donnell, John M; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Belier, Gilbert; Laurent, Benoit; Noda, Shusaku

    2010-01-01

    An experimental campaign was started in 2002 in the framework of a collaboration belween CEA-DAM and the Los Alamos National Laboratory to measure the prompt fission neutron spectra (PFNS) for incident neutron energies from 1 to 200 MeV with consistent error uncertainties over the whole energy range. The prompt neutron spectra in {sup 235,238}U(n,f) and {sup 237}Np(n,f) have been already studied successfully. A first attempt to characterize the prompt neutrons emitted during the fission of the {sup 239}Pu was done in 2007. This contribution will focus on the results obtained during the final experiment to measure the PFNS in {sup 239}Pu(n,f) performed in 2008. Prompt fission neutron spectra in the neutron-induced fission of {sup 239}Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Mean energies obtained from the spectra are discussed and compared to theoretical model calculation.

  13. Neutron and gamma dose and spectra measurements on the Little Boy replica

    SciTech Connect

    Hoots, S.; Wadsworth, D.

    1984-06-01

    The radiation-measurement team of the Weapons Engineering Division at Lawrence Livermore National Laboratory (LLNL) measured neutron and gamma dose and spectra on the Little Boy replica at Los Alamos National Laboratory (LANL) in April 1983. This assembly is a replica of the gun-type atomic bomb exploded over Hiroshima in 1945. These measurements support the National Academy of Sciences Program to reassess the radiation doses due to atomic bomb explosions in Japan. Specifically, the following types of information were important: neutron spectra as a function of geometry, gamma to neutron dose ratios out to 1.5 km, and neutron attenuation in the atmosphere. We measured neutron and gamma dose/fission from close-in to a kilometer out, and neutron and gamma spectra at 90 and 30/sup 0/ close-in. This paper describes these measurements and the results. 12 references, 13 figures, 5 tables.

  14. Fast-neutron activation of long-lived nuclides in natural Pb

    NASA Astrophysics Data System (ADS)

    Guiseppe, V. E.; Elliott, S. R.; Fields, N. E.; Hixon, D.

    2015-04-01

    We measured the production of the long-lived nuclides 207 Bi, 202 Pb, and 194 Hg in a sample of natural Pb due to high-energy neutron interactions using a neutron beam at the Los Alamos Neutron Science Center. The activated sample was counted by a HPGe detector to measure the amount of radioactive nuclides present. These nuclides are critical in understanding potential backgrounds in low background experiments utilizing large amounts of Pb shielding due to cosmogenic neutron interactions in the Pb while residing on the Earth's surface. By scaling the LANSCE neutron flux to a cosmic neutron flux, we measure the sea level cosmic ray production rates of 8.0 ± 1.3 atoms/kg/day of 194 Hg, 120 ± 25 atoms/kg/day 202 Pb, and <0.17 ± 0.04 atoms/kg/day 207 Bi.

  15. The Los Alamos primer

    SciTech Connect

    Serber, R.

    1992-01-01

    This book contains the 1943 lecture notes of Robert Serber. Serber was a protege of J. Robert Oppenheimer and member of the team that built the first atomic bomb - reveal what the Los Alamos scientists knew, and did not know, about the terrifying weapon they were building.

  16. PREFACE: Workshop on 'Buried' Interface Science with X-rays and Neutrons

    NASA Astrophysics Data System (ADS)

    Sakurai, Kenji

    2007-06-01

    The 2007 workshop on `buried' interface science with X-rays and neutrons was held at the Institute of Materials Research, Tohoku University, in Sendai, Japan, on July 22-24, 2007. The workshop was the latest in a series held since 2001; Tsukuba (December 2001), Niigata (September 2002), Nagoya (July 2003), Tsukuba (July 2004), Saitama (March 2005), Yokohama (July 2006), Kusatsu (August 2006) and Tokyo (December 2006). The 2007 workshop had 64 participants and 34 presentations. There are increasing demands for sophisticated metrology in order to observe multilayered materials with nano-structures (dots, wires, etc), which are finding applications in electronic, magnetic, optical and other devices. Unlike many other surface-sensitive methods, X-ray and neutron analysis is known for its ability to see even `buried' function interfaces as well as the surface. It is highly reliable in practice, because the information, which ranges from the atomic to mesoscopic scale, is quantitative and reproducible. The non-destructive nature of this type of analytical method ensures that the same specimen can be measured by other techniques. However, we now realize that the method should be upgraded further to cope with more realistic problems in nano sciences and technologies. In the case of the reflectivity technique and other related methods, which have been the main topics in our workshops over the past 7 years, there are three important directions as illustrated in the Figure. Current X-ray methods can give atomic-scale information for quite a large area on a scale of mm2-cm2. These methods can deliver good statistics for an average, but sometimes we need to be able to see a specific part in nano-scale rather than an average structure. In addition, there is a need to see unstable changing structures and related phenomena in order to understand more about the mechanism of the functioning of nano materials. Quick measurements are therefore important. Furthermore, in order to apply

  17. Los Alamos Team Demonstrates Bottle Scanner Technology

    SciTech Connect

    Espy, Michelle; Schultz, Larry

    2014-05-06

    Los Alamos scientists are demonstrating a Nuclear Magnetic Resonance Imaging (NMR) technology that may provide a breakthrough for screening liquids at airport security. By adding low-power X-ray data to the NMR mix, scientists believe they have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new technology is called MagRay.

  18. Los Alamos Team Demonstrates Bottle Scanner Technology

    ScienceCinema

    Espy, Michelle; Schultz, Larry

    2014-06-02

    Los Alamos scientists are demonstrating a Nuclear Magnetic Resonance Imaging (NMR) technology that may provide a breakthrough for screening liquids at airport security. By adding low-power X-ray data to the NMR mix, scientists believe they have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new technology is called MagRay.

  19. Lanl Neutron-Induced Fission Cross Section Measurement Program

    NASA Astrophysics Data System (ADS)

    Laptev, A. B.; Tovesson, F.; Hill, T. S.

    2014-09-01

    A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). Combining measurements at two LANSCE facilities, the Lujan Center and the Weapons Neutron Research facility (WNR), cover neutron energies over 10 orders of magnitude: from sub-thermal up to 200 MeV. A parallel-plate fission ionization chamber was used as a fission fragment detector. The 235U(n,f) standard was used as the reference. Fission cross sections have been measured for multiple actinides. The new data presented here completes the suite of long-lived Uranium isotopes that were investigated with this experimental approach. The cross section data are presented in comparison with existing evaluations and previous measurements.

  20. Progress on the Europium Neutron-Capture Study using DANCE

    SciTech Connect

    Agvaanluvsan, U; Becker, J A; Macri, R A; Parker, W; Wilk, P; Wu, C Y; Bredeweg, T A; Esch, E; Haight, R C; O'Donnell, J M; Reifarth, R; Rundberg, R S; Schwantes, J M; Ullmann, J L; Vieira, D J; Wilhelmy, J B; Wouters, J M; Mitchell, G E; Sheets, S A; Becvar, F; Krticka, M

    2006-09-05

    The accurate measurement of neutron-capture cross sections of the Eu isotopes is important for many reasons including nuclear astrophysics and nuclear diagnostics. Neutron capture excitation functions of {sup 151,153}Eu targets were measured recently using a 4{pi} {gamma}-ray calorimeter array DANCE located at the Los Alamos Neutron Science Center for E{sub n} = 0.1-100 keV. The progress on the data analysis efforts is given in the present paper. The {gamma}-ray multiplicity distributions for the Eu targets and Be backing are significantly different. The {gamma}-ray multiplicity distribution is found to be the same for different neutron energies for both {sup 151}Eu and {sup 153}Eu. The statistical simulation to model the {gamma}-ray decay cascade is summarized.

  1. The Status of Cross Section Measurements for Neutron-induced Reactions Needed for Cosmic Ray Studies

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.

    2003-01-01

    Cosmic ray interactions with lunar rocks and meteorites produce small amounts of radionuclides and stable isotopes. Advances in Accelerator Mass Spectrometry (AMS) allow production rates to be measured routinely in well-documented lunar rocks and meteorites. These measurements are analyzed using theoretical models to learn about the object itself and the history of the cosmic rays that fell on it. Good cross section measurements are essential input to the theoretical calculations. Most primary cosmic ray particles are protons so reliable cross sections for proton-induced reactions are essential. A cross section is deemed accurate if measurements made by different experimenters using different techniques result in consistent values. Most cross sections for proton induced reactions are now well measured. However, good cross section measurements for neutron-induced reactions are still needed. These cross sections are required to fully account for all galactic cosmic ray interactions at depth in an extraterrestrial object. When primary galactic cosmic ray (GCR) particles interact with an object many secondary neutrons are produced, which also initiate spallation reactions. Thus, the total GCR contribution to the overall cosmogenic nuclide archive has to include the contribution from the secondary neutron interactions. Few relevant cross section measurements have been reported for neutron-induced reactions at neutron energies greater than approximately 20 MeV. The status of the cross section measurements using quasi-monoenergetic neutron energies at iThemba LABS, South Africa and white neutron beams at Los Alamos Neutron Science Center (LANSCE), Los Alamos are reported here.

  2. Determination of mixed proton/neutron fluences in the LANSCE irradiation environment

    SciTech Connect

    James, M.R.; Maloy, S.A; Sommer, W.F.; Ferguson, P.; Fowler, M.M.; Corzine, K.

    1998-12-31

    In support of the Accelerator Production of Tritium (APT) program, several materials were exposed to a high-energy proton and spallation neutron environments. Large differences in mechanical property changes in this environment are expected compared to the typical fusion or fission systems. To make proper dose correlations, it is important to accurately quantify the fluences. Activation foils consisting of a stack of disks of Co, Ni, Fe, Al, Nb and Cu were irradiated concurrent with mechanical testing samples in the Los Alamos Spallation Radiation Effects Facility (LASREF) at the Los Alamos Neutron Science Center (LANSCE) facility. The irradiation consisted of an 800 MeV, 1 mA proton beam and a W target in the beam provided a source of spallation neutrons. The maximum proton fluence was around 3 {times} 10{sup 21} p/cm{sup 2} and the maximum neutron fluence approximately 3 {times} 10{sup 20} n/cm{sup 2}. After irradiation, the foils were withdrawn and the radioactive isotopes analyzed using gamma spectroscopy. From initial estimates for the fluences and spectra derived from the Los Alamos High-Energy Transport (LAHET) Code System (LCS), comparisons to the measured levels of activation products were made. The Na-22 activation products in the Al foils were measured from different regions of the target in order to profile the spatial levels of the fluences. These tests gave empirical confirmation of the proton and neutron fluences of the irradiated samples throughout the target region.

  3. Global Map of Thermal Neutrons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations by NASA's 2001 Mars Odyssey spacecraft show a global view of Mars in low energy, or thermal, neutrons. Thermal neutrons are sensitive to the presence of hydrogen and the presence of carbon dioxide, in this case 'dry ice' frost. The red area at the top of the map indicates that about one meter (three feet) of carbon dioxide frost covers the surface, as it does every Mars winter in the polar regions. Soil enriched by hydrogen is indicated by the deep blue colors on the map, which show a low intensity of thermal neutrons. An enhancement of thermal neutrons close to the south pole, seen as a light green color, indicates the presence of residual carbon dioxide in the south polar cap, even though the annual frost dissipated from that region during southern summer.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  4. LANSCE nuclear science facilities and activities

    SciTech Connect

    Nelson, Ronald O

    2010-01-01

    Nuclear science activities at the Los Alamos Neutron Science Center (LANSCE) encompass measurements spanning the neutron energy range from thermal to 600 MeV. The neutron sources use spallation of the LANSCE 800 MeV pulsed proton beam with the time-of-flight technique to measure properties of neutron-induced reactions as a function of energy over this large energy range. Current experiments are conducted at the Lujan Center moderated neutron source, the unmoderated WNR target, and with a lead-slowing-down spectrometer. Instruments in use include the DANCE array of BaF{sub 2} scintillators for neutron capture studies, the FIGARO array of liquid scintillator neutron detectors, the GEANIE array of high-resolution HPGe x-ray and gamma-ray detectors, and a number of fission chambers, and other detectors. The LANL capabilities for production and handling of radioactive materials coupled with the neutron sources and detectors at LANSCE are enabling new and challenging measurements for a variety of applications including nuclear energy and nuclear astrophysics. An overview of recent research and examples of results is presented.

  5. Development of the Probing In-Situ with Neutron and Gamma Rays (PING) Instrument for Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology that has been used successfully in oil field well logging and mineral exploration on Earth for decades. Similar techniques can be very powerful for non-invasive in situ measurements of the subsurface elemental composition on other planets. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring instruments using this technology to the point where they can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets. PING combines a 14 MeV deuterium-tritium pulsed neutron generator with a gamma ray spectrometer and two neutron detectors to produce a landed instrument that can determine the elemental composition of a planet down to 30 - 50 cm below the planet's surface. The penetrating nature of.5 - 10 MeV gamma rays and 14 MeV neutrons allows such sub-surface composition measurements to be made without the need to drill into or otherwise disturb the planetary surface, thus greatly simplifying the lander design. We are currently testing a PING prototype at a unique outdoor neutron instrumentation test facility at NASA/GSFC that provides two large (1.8 m x 1.8 m x.9 m) granite and basalt test formations placed outdoors in an empty field. Since an independent trace elemental analysis has been performed on both the Columbia River basalt and Concord Gray granite materials, these samples present two known standards with which to compare PING's experimentally measured elemental composition results. We will present experimental results from PING measurements of both the granite and basalt test formations and show how and why the optimum PING instrument operating parameters differ for studying the two materials.

  6. "Measurements of the neutron spectrum in transit to Mars on the Mars Science Laboratory", Köhler et al.

    NASA Astrophysics Data System (ADS)

    Miller, Jack

    2015-04-01

    The Mars Science Laboratory (MSL) spacecraft carried the Curiosity rover to Mars. While the dramatic, successful landing of Curiosity and its subsequent exploration of the Martian surface have justifiably generated great excitement, from the standpoint of the health of crewmembers on missions to Mars, knowledge of the environment between Earth and Mars is critical. This paper reports data taken during the cruise phase of the MSL by the Radiation Assessment Detector (RAD). The results are of great interest for several reasons. They are a direct measurement of the radiation environment during what will be a significant fraction of the duration of a proposed human mission to Mars; they were made behind the de facto shielding provided by various spacecraft components; and, in particular, they are a measurement of the contribution to radiation dose by neutrons. The neutron environment inside spacecraft is produced primarily by galactic cosmic ray ions interacting in shielding materials, and given the high biological effectiveness of neutrons and the increased contribution of neutrons to dose with increased depth in shielding, accurate knowledge of the neutron energy spectrum behind shielding is vital. The results show a relatively modest contribution from neutrons and gammas compared to that from charged particles, but also a discrepancy in both dose and dose rate between the data and simulations. The failure of the calculations to accurately reproduce the data is significant, given that future manned spacecraft will be more heavily shielded (and thus produce more secondary neutrons) and that spacecraft design will rely on simulations and model calculations of radiation transport. The methodology of risk estimation continues to evolve, and incorporates our knowledge of both the physical and biological effects of radiation. The relatively large uncertainties in the biological data, and the difficulties in reducing those uncertainties, makes it all the more important to

  7. Neutron-Induced Charged Particle Studies at LANSCE

    NASA Astrophysics Data System (ADS)

    Lee, Hye Young; Haight, Robert C.

    2014-09-01

    Direct measurements on neutron-induced charged particle reactions are of interest for nuclear astrophysics and applied nuclear energy. LANSCE (Los Alamos Neutron Science Center) produces neutrons in energy of thermal to several hundreds MeV. There has been an effort at LANSCE to upgrade neutron-induced charged particle detection technique, which follows on (n,z) measurements made previously here and will have improved capabilities including larger solid angles, higher efficiency, and better signal to background ratios. For studying cross sections of low-energy neutron induced alpha reactions, Frisch-gridded ionization chamber is designed with segmented anodes for improving signal-to-noise ratio near reaction thresholds. Since double-differential cross sections on (n,p) and (n,a) reactions up to tens of MeV provide important information on deducing nuclear level density, the ionization chamber will be coupled with silicon strip detectors (DSSD) in order to stop energetic charged particles. In this paper, we will present the status of this development including the progress on detector design, calibrations and Monte Carlo simulations. This work is funded by the US Department of Energy - Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

  8. Two detector arrays for fast neutrons at LANSCE

    NASA Astrophysics Data System (ADS)

    Haight, R. C.; Lee, H. Y.; Taddeucci, T. N.; O'Donnell, J. M.; Perdue, B. A.; Fotiades, N.; Devlin, M.; Ullmann, J. L.; Laptev, A.; Bredeweg, T.; Jandel, M.; Nelson, R. O.; Wender, S. A.; White, M. C.; Wu, C. Y.; Kwan, E.; Chyzh, A.; Henderson, R.; Gostic, J.

    2012-03-01

    The neutron spectrum from neutron-induced fission needs to be known in designing new fast reactors, predicting criticality for safety analyses, and developing techniques for global security application. The experimental data base of fission neutron spectra is very incomplete and most present evaluated libraries are based on the approach of the Los Alamos Model. To validate these models and to provide improved data for applications, a program is underway to measure the fission neutron spectrum for a wide range of incident neutron energies using the spallation source of fast neutrons at the Weapons Neutron Research (WNR) facility at the Los Alamos Neutron Science Center (LANSCE). In a double time-of-flight experiment, fission neutrons are detected by arrays of neutron detectors to increase the solid angle and also to investigate possible angular dependence of the fission neutrons. The challenge is to measure the spectrum from low energies, down to 100 keV or so, to energies over 10 MeV, where the evaporation-like spectrum decreases by 3 orders of magnitude from its peak around 1 MeV. For these measurements, we are developing two arrays of neutron detectors, one based on liquid organic scintillators and the other on 6Li-glass detectors. The range of fission neutrons detected by organic liquid scintillators extends from about 600 keV to well over 10 MeV, with the lower limit being defined by the limit of pulse-shape discrimination. The 6Li-glass detectors have a range from very low energies to about 1 MeV, where their efficiency then becomes small. Various considerations and tests are in progress to understand important contributing factors in designing these two arrays and they include selection and characterization of photomultiplier tubes (PM), the performance of relatively thin (1.8 cm) 6Li-glass scintillators on 12.5 cm diameter PM tubes, use of 17.5 cm diameter liquid scintillators with 12.5 cm PM tubes, measurements of detector efficiencies with tagged neutrons

  9. Nuclear Forensics at Los Alamos National Laboratory

    SciTech Connect

    Podlesak, David W; Steiner, Robert E.; Burns, Carol J.; LaMont, Stephen P.; Tandon, Lav

    2012-08-09

    The overview of this presentation is: (1) Introduction to nonproliferation efforts; (2) Scope of activities at Los Alamos National Laboratory; (3) Facilities for radioanalytical work at LANL; (4) Radiochemical characterization capabilities; and (5) Bulk chemical and materials analysis capabilities. Some conclusions are: (1) Analytical chemistry measurements on plutonium and uranium matrices are critical to numerous defense and non-defense programs including safeguards accountancy verification measurements; (2) Los Alamos National Laboratory operates capable actinide analytical chemistry and material science laboratories suitable for nuclear material forensic characterization; (3) Actinide analytical chemistry uses numerous means to validate and independently verify that measurement data quality objectives are met; and (4) Numerous LANL nuclear facilities support the nuclear material handling, preparation, and analysis capabilities necessary to evaluate samples containing nearly any mass of an actinide (attogram to kilogram levels).

  10. Investigation of the Statistical Properties of Stable Eu Nuclei using Neutron-Capture Reactions

    SciTech Connect

    Agvaanluvsan, U; Alpizar-Vicente, A; Becker, J A; Becvar, F; Bredeweg, T A; Clement, R; Esch, E; Folden, III, C M; Hatarik, R; Haight, R C; Hoffman, D C; Krticka, M; Macri, R A; Mitchell, G E; Nitsche, H; O'Donnell, J M; Parker, W; Reifarth, R; Rundberg, R S; Schwantes, J M; Sheets, S A; Ullmann, J L; Vieira, D J; Wilhelmy, J B; Wilk, P; Wouters, J M; Wu, C Y

    2005-10-04

    Neutron capture for incident neutron energies <1eV up to 100 keV has been measured for {sup 151,153}Eu targets. The highly efficient DANCE (Detector for Advanced Neutron Capture Experiments) array coupled with the intense neutron beam at Los Alamos Neutron Science Center is used for the experiment. Stable Eu isotopes mass separated and electroplated on Be backings were used. Properties of well-resolved, strong resonances in two Eu nuclei are examined. The parameters for most of these resonances are known. Detailed multiplicity information for each resonance is obtained employing the high granularity of the DANCE array. The radiative decay cascades corresponding to each resonance are obtained in the experiment. The measurements are compared to simulation of these cascades which calculated with various models for the radiative strength function. Comparison between the experimental data and simulation provides an opportunity to investigate the average quantities.

  11. High-energy neutron dosimetry

    NASA Astrophysics Data System (ADS)

    Sutton, Michele Rhea

    2001-12-01

    Fluence-to-dose conversion coefficients for the radiation protection quantity effective dose were calculated for neutrons, photons and protons with energies up to 2 GeV using the MCNPX code. The calculations were performed using the Pacific Northwest National Laboratory versions of the MIRD-V male and female anthropomorphic phantoms modified to include the skin and esophagus. The latest high-energy neutron evaluated cross-section libraries and the recommendations given in ICRP Publication 60 and ICRP Publication 74 were utilized to perform the calculations. Sets of fluence-to- effective dose conversion coefficients are given for anterior-posterior, posterior-anterior, left-lateral, right-lateral and rotational irradiation geometries. This is the first set of dose conversion coefficients over this energy range calculated for the L-LAT irradiation geometry. A unique set of high-energy neutron depth-dose benchmark experiments were performed at the Los Alamos Neutron Science Center/Weapons Neutron Research (LANSCE/WNR) complex. The experiments consisted of filtered neutron beams with energies up to 800 MeV impinging on a 30 x 30 x 30 cm3 tissue-equivalent phantom. The absorbed dose was measured in the phantom at various depths with tissue-equivalent ion chambers. The phantom and the experimental set-up were modeled using MCNPX. Comparisons of the experimental and computational depth- dose distributions indicate that the absorbed dose calculated by MCNPX is within 13% for neutrons with energies up to 750 MeV. This experiment will serve as a benchmark experiment for the testing of high-energy radiation transport codes for the international radiation protection community.

  12. Economic Effects of the Spallation Neutron Source (SNS) and the Joint Institute for Neutron Sciences (JINS) on the State of Tennessee

    SciTech Connect

    Univ of TN, Center for Business Research

    2002-12-18

    This report provides an analysis of the economic impacts arising from the construction and operation of the Spallation Neutron Source (SNS) and Joint Institute of Neutron Science (JINS) facilities on the State of Tennessee. The study was conducted by the Center for Business and Economic Research (CBER) at the University of Tennessee, Knoxville, in cooperation with the Oak Ridge National Laboratory (ORNL) and the Science Alliance at UTK. Estimates provided are based on data provided by ORNL and the Office of Research at UTK. The estimates contained in the report quantify the income, employment, and sales tax revenue which will be generated by the activities of the SNS and JINS by accounting for the (1) direct impacts, those arising directly from the expenditures for the construction and operation of the facilities; (2) indirect impacts, those arising from the visitors to the facilities and from facility expenditures in Tennessee; and (3) multiplier impacts, those arising from the ripple effects created as new income is spent and respent in the state economy.

  13. Type A Accident Investigation Board report on the January 17, 1996, electrical accident with injury in Technical Area 21 Tritium Science and Fabrication Facility Los Alamos National Laboratory. Final report

    SciTech Connect

    1996-04-01

    An electrical accident was investigated in which a crafts person received serious injuries as a result of coming into contact with a 13.2 kilovolt (kV) electrical cable in the basement of Building 209 in Technical Area 21 (TA-21-209) in the Tritium Science and Fabrication Facility (TSFF) at Los Alamos National Laboratory (LANL). In conducting its investigation, the Accident Investigation Board used various analytical techniques, including events and causal factor analysis, barrier analysis, change analysis, fault tree analysis, materials analysis, and root cause analysis. The board inspected the accident site, reviewed events surrounding the accident, conducted extensive interviews and document reviews, and performed causation analyses to determine the factors that contributed to the accident, including any management system deficiencies. Relevant management systems and factors that could have contributed to the accident were evaluated in accordance with the guiding principles of safety management identified by the Secretary of Energy in an October 1994 letter to the Defense Nuclear Facilities Safety Board and subsequently to Congress.

  14. The early development of neutron diffraction: science in the wings of the Manhattan Project.

    PubMed

    Mason, T E; Gawne, T J; Nagler, S E; Nestor, M B; Carpenter, J M

    2013-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan's group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool. PMID:23250059

  15. Radonuclide concentrations in bees and honey in the vicinity of Los Alamos National Laboratory

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.

    1996-06-01

    Honeybees are effective monitors of environmental pollution; they forage for P len and nectar over a large area ({congruent}7 km{sup 2}), accumulate contaminants from air, water, plants, and soil, and return to a fixed location (the hive) for sampling. Los Alamos National Laboratory (LANL), in fact, has maintained a network of honeybee colonies within and around LANL for 16 years (1979 to 1994); the objectives for maintaining this honeybee network were to (1) determine the bioavailability of radionuclides in the environment, and (2) the committed effective dose equivalent (CEDE) to people who may consume honey from these beehives (Los Alamos and White Rock/Pajarito Acres lownsites). Of all the radionuclides studied over the years, tritium (314) was consistently picked up by the bees and was most readily transferred to the honey. Tritium in honey collected from hives located within LANL, for example, ranged in concentration from 0.07 Bq mL{sup -1} (1.9 pCi mL{sup -1}) to 27.75 Bq mL{sup -1} (749.9 pCi mL{sup -1}) (LANL Neutron Science Center); the average concentration of {sup 3}H in honey Collected from hives located around the LANL area (perimeter) ranged in concentration from 0.34 Bq mL{sup -1} (9.3 pCi mL{sup -1}) (White Rock/Pajarito Acres townsite) to 3.67 Bq mL{sup -1} (99.3 pCi mL{sup -1}) (Los Alamos townsite). Overall, the CEDE-based on the average concentration of all radionuclides measured over the years-from consuming 5 kg (11 lbs) of honey collected from hives located within the townsites of Los Alamos and White Rock/Pajarito Acres, after regional (background) as been subtracted, was 0.074 {mu}Sv y{sup -1} (0.0074 mrem y{sup -1}) and 0.024 pSv y{sup -1} (0.0024 mrem y{sup -1}), respectively. The highest CEDE, based on the mean + 2 standard deviations (95% confidence level), was 0.334 fiSv y{sup -1} (0.0334 mrem y{sup -1}) (Los Alamos townsitc).

  16. Preparation of thin arsenic and radioarsenic targets for neutron capture studies

    SciTech Connect

    Fassbender, Michael E

    2009-01-01

    A simple method for the electrodeposition of elemental arsenic (As) on a metal backing from aqueous solutions has been developed. The method was successfully applied to stable As (As-75). Thin (2.5 mg {center_dot} cm{sup -2}) coherent, smooth layers of the metalloid on Ti foils (2.5 {micro}m thickness) were obtained. Electrodeposits served as targets for {sup 75}As(n,{gamma}) {sup 76}As neutron capture experiments at Los Alamos Neutron Science Center (LANSCE). Respective {sup 73}As(n,{gamma}) {sup 74}As experiments are planned for the near future, and {sup 73}As targets will be prepared in a similar fashion utilizing the introduced electrodeposition method. The preparation of an {sup 73}As (half-life 80.3 d) plating bath solution from proton irradiated germanium has been demonstrated. Germanium target irradiation was performed at the Los Alamos Isotope Production Facility (IPF).

  17. Global Map of Epithermal Neutrons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations by NASA's 2001 Mars Odyssey spacecraft show a global view of Mars in intermediate-energy, or epithermal, neutrons. Soil enriched by hydrogen is indicated by the deep blue colors on the map, which show a low intensity of epithermal neutrons. Progressively smaller amounts of hydrogen are shown in the colors light blue, green, yellow and red. The deep blue areas in the polar regions are believed to contain up to 50 percent water ice in the upper one meter (three feet) of the soil. Hydrogen in the far north is hidden at this time beneath a layer of carbon dioxide frost (dry ice). Light blue regions near the equator contain slightly enhanced near-surface hydrogen, which is most likely chemically or physically bound because water ice is not stable near the equator. The view shown here is a map of measurements made during the first three months of mapping using the neutron spectrometer instrument, part of the gamma ray spectrometer instrument suite. The central meridian in this projection is zero degrees longitude. Topographic features are superimposed on the map for geographic reference.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Critical partnerships: Los Alamos, universities, and industry

    SciTech Connect

    Berger, C.L.

    1997-04-01

    Los Alamos National Laboratory, situated 35 miles northwest of Santa Fe, NM, is one of the Department of Energy`s three Defense Programs laboratories. It encompasses 43 square miles, employees approximately 10,000 people, and has a budget of approximately $1.1B in FY97. Los Alamos has a strong post-cold war mission, that of reducing the nuclear danger. But even with that key role in maintaining the nation`s security, Los Alamos views partnerships with universities and industry as critical to its future well being. Why is that? As the federal budget for R&D comes under continued scrutiny and certain reduction, we believe that the triad of science and technology contributors to the national system of R&D must rely on and leverage each others capabilities. For us this means that we will rely on these partners to help us in 5 key ways: We expect that partnerships will help us maintain and enhance our core competencies. In doing so, we will be able to attract the best scientists and engineers. To keep on the cutting edge of research and development, we have found that partnerships maintain the excellence of staff through new and exciting challenges. Additionally, we find that from our university and corporate partners we often learn and incorporate {open_quotes}best practices{close_quotes} in organizational management and operations. Finally, we believe that a strong national system of R&D will ensure and enhance our ability to generate revenues.

  19. The early development of neutron diffraction: Science in the wings of the Manhattan Project

    SciTech Connect

    Mason, Thom; Gawne, Timothy J; Nagler, Stephen E; Nestor, Margaret Boone {Bonnie}; Carpenter, John M

    2012-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurements of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst, and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor.

  20. Los Alamos low-level waste performance assessment status

    SciTech Connect

    Wenzel, W.J.; Purtymun, W.D.; Dewart, J.M.; Rodgers, J.E.

    1986-06-01

    This report reviews the documented Los Alamos studies done to assess the containment of buried hazardous wastes. Five sections logically present the environmental studies, operational source terms, transport pathways, environmental dosimetry, and computer model development and use. This review gives a general picture of the Los Alamos solid waste disposal and liquid effluent sites and is intended for technical readers with waste management and environmental science backgrounds but without a detailed familiarization with Los Alamos. The review begins with a wide perspective on environmental studies at Los Alamos. Hydrology, geology, and meteorology are described for the site and region. The ongoing Laboratory-wide environmental surveillance and waste management environmental studies are presented. The next section describes the waste disposal sites and summarizes the current source terms for these sites. Hazardous chemical wastes and liquid effluents are also addressed by describing the sites and canyons that are impacted. The review then focuses on the transport pathways addressed mainly in reports by Healy and Formerly Utilized Sites Remedial Action Program. Once the source terms and potential transport pathways are described, the dose assessment methods are addressed. Three major studies, the waste alternatives, Hansen and Rogers, and the Pantex Environmental Impact Statement, contributed to the current Los Alamos dose assessment methodology. Finally, the current Los Alamos groundwater, surface water, and environmental assessment models for these mesa top and canyon sites are described.

  1. Neutron capture measurements on unstable nuclei at LANSCE

    SciTech Connect

    Ullmann, J. L.; Haight, R. C.; Fowler, M. M.; Miller, G. G.; Rundberg, R. S.; Wilhelmy, J. B.

    1999-06-10

    Although neutron capture by stable isotopes has been extensively measured, there are very few measurements on unstable isotopes. The intense neutron flux at the Manual Lujan Jr. Neutron Scattering Center at LANSCE enables us to measure capture on targets with masses of about 1 mg over the energy range from 1 eV to 100 keV. These measurements are important not only for understanding the basic physics, but also for calculations of stellar nucleosynthesis and Science-Based Stockpile Stewardship. Preliminary measurements on {sup 169}Tm and {sup 171}Tm have been made with deuterated benzene detectors. A new detector array at the Lujan center and a new radioactive isotope separator will combine to give Los Alamos a unique capability for making these measurements.

  2. Split-target neutronics and the MLNSC spallation target system

    SciTech Connect

    Russell, G.J.; Ferguson, P.D.; Pitcher, E.J.; Court, J.D.

    1996-12-31

    The Manuel Lujan, Jr., Neutron Scattering Center (MLNSC) at the Los Alamos National Laboratory is one of four operating Short-Pulse Spallation Sources worldwide. The MLNSC target system (composed of targets, moderators, and reflectors) was first installed in 1985. The target system employs a split tungsten spallation target with a void space in between (the flux-trap gap); this target system will be upgraded in 1998. The ability to efficiently split a spallation target allowed us to introduce the concept of flux-trap moderators and ultimately the notion of backscattering and upstream moderators. The upgraded MLNSC target system will employ both flux-trap and upstream/backscattering moderators to simultaneously service 16 neutron flight paths with high-intensity neutron beams for materials science research.

  3. Occurrences at Los Alamos National Laboratory: What can they tell us?

    SciTech Connect

    Richard A. Reichelt; A. Jeffery Eichorst; Marc E. Clay; Rita J. Henins; Judith D. DeHaven; Richard J. Brake

    2000-03-01

    The authors analyzed the evolution of institutional and facility response to groups of abnormal incidents at Los Alamos National Laboratory (LANL). The analysis is divided into three stages: (1) the LANL response to severe accidents from 1994 to 1996, (2) the LANL response to facility-specific clusters of low-consequence incidents from 1997 to 1999, and (3) the ongoing development of and response to a Laboratory-wide trending and analysis program. The first stage is characterized by five severe accidents at LANL--a shooting fatality, a forklift accident, two electrical shock incidents, and an explosion in a nuclear facility. Each accident caused LANL and the Department of Energy (DOE) to launch in-depth investigations. A recurrent theme of the investigations was the failure of LANL and DOE to identify and act on precursor or low-consequence events that preceded the severe accidents. The second stage is characterized by LANL response to precursor or low-consequence incidents over a two-year period. In this stage, the Chemistry and Metallurgy Research Facility, the Los Alamos Critical Experiments Facility, and the Los Alamos Neutron Science Center responded to an increase in low-consequence events by standing down their facilities. During the restart process, each facility collectively analyzed the low-consequence events and developed systemic corrective actions. The third stage is characterized by the development of a Laboratory-wide trending and analysis program, which involves proactive division-level analysis of incidents and development of systemic actions. The authors conclude that, while the stages show an encouraging evolution, the facility standdowns and restarts are overly costly and that the institutional trending and analysis program is underutilized. The authors therefore recommend the implementation of an institutional, mentored program of trending and analysis that identifies clusters of related low-consequence events, analyzes those events, and

  4. Neutron beam testing of triblades

    SciTech Connect

    Michalak, Sarah E; Du Bois, Andrew J; Storlie, Curtis B; Rust, William N; Du Bois, David H; Modl, David G; Quinn, Heather M; Blanchard, Sean P; Manuzzato, Andrea

    2010-12-16

    Four IBM Triblades were tested in the Irradiation of Chips and Electronics facility at the Los Alamos Neutron Science Center. Triblades include two dual-core Opteron processors and four PowerXCell 8i (Cell) processors. The Triblades were tested in their field configuration while running different applications, with the beam aimed at the Cell processor or the Opteron running the application. Testing focused on the Cell processors, which were tested while running five different applications and an idle condition. While neither application nor Triblade was statistically important in predicting the hazard rate, the hazard rate when the beam was aimed at the Opterons was significantly higher than when it was aimed at the Cell processors. In addition, four Cell blades (one in each Triblade) suffered voltage shorts, leading to their inoperability. The hardware tested is the same as that in the Roadrunner supercomputer.

  5. Status of optical model activities at Los Alamos National Laboratory

    SciTech Connect

    Young, P.G.

    1995-12-01

    An update will be given of activities at Los Alamos National Laboratory aimed at developing optical model potentials for applied calculations. Recent work on a coupled-channels potential for neutron reactions on {sup 241,243}Am and spherical neutron potential updates for {sup 56}Fe and {sup 59}Co will be presented, together with examples of their application in nuclear reaction calculations with the GNASH code system. New potentials utilized in evaluations at Livermore for {sup 12}C, {sup 14}N and {sup 16}O are described and additional potentials from earlier analyses at Los Alamos of Ti, V, and Ni data are made available for possible inclusion in the Reference Input Parameter Library (RIPL) for nuclear model calculations of nuclear data. Specific activities directed at development of the optical potential segment of the RIPL will be summarized.

  6. The early development of neutron diffraction: science in the wings of the Manhattan Project

    SciTech Connect

    Mason, T. E. Gawne, T. J.; Nagler, S. E.; Nestor, M. B.; Carpenter, J. M.

    2013-01-01

    Early neutron diffraction experiments performed in 1944 using the first nuclear reactors are described. Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan’s group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool.

  7. Skylab neutron environment experiment (Science Demonstration SD-34 (TV108)). Description and preliminary results

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.

    1974-01-01

    Neutron and proton induced radioactivity at various locations within Skylab were measured. Samples of five metals were formed into activation packets and deployed at the following locations on the Skylab 4 mission: orbital workshop film vault, water storage tank, and two opposing orbital workshop internal locations. Radioactive nuclides were produced in the packets by nuclear interactions of high-energy protons and secondary neutrons within Skylab. Low-level gamma ray spectroscopy measurements were made on the returned packets to determine the incident neutron and proton fluxes and spectra and their variations with mass distribution.

  8. Technical manpower needs and resources at Los Alamos National Laboratory

    SciTech Connect

    Freese, K.B.

    1984-01-01

    The Los Alamos National Laboratory has begun a program to share its scientific and technological expertise with students and teachers in the surrounding area. The goal of the Laboratory's Educational Outreach Program is to stimulate an awareness of professional opportunities in the sciences and engineering.

  9. The early development of neutron diffraction: science in the wings of the Manhattan Project

    PubMed Central

    Mason, T. E.; Gawne, T. J.; Nagler, S. E.; Nestor, M. B.; Carpenter, J. M.

    2013-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan’s group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool. PMID:23250059

  10. Los Alamos safeguards program overview and NDA in safeguards

    SciTech Connect

    Keepin, G.R.

    1988-01-01

    Over the years the Los Alamos safeguards program has developed, tested, and implemented a broad range of passive and active nondestructive analysis (NDA) instruments (based on gamma and x-ray detection and neutron counting) that are now widely employed in safeguarding nuclear materials of all forms. Here very briefly, the major categories of gamma ray and neutron based NDA techniques, give some representative examples of NDA instruments currently in use, and cite a few notable instances of state-of-the-art NDA technique development. Historical aspects and a broad overview of the safeguards program are also presented.

  11. CONFERENCES AND SYMPOSIA: Plasma phenomena in nanostructures and neutron stars Scientific Session of the Physical Sciences Division of the Russian Academy of Sciences (26 March 2008)

    NASA Astrophysics Data System (ADS)

    Klimov, V. V.; Istomin, Ya N.; Kosevich, Yu A.

    2008-08-01

    A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held on 26 March 2008 at the conference hall of the P N Lebedev Physical Institute, RAS. The following reports were presented at the session: (1) Klimov V V (P N Lebedev Physical Institute, RAS, Moscow) "Nanoplasmonics"; (2) Istomin Ya N (P N Lebedev Physical Institute, RAS, Moscow) "Electron-positron plasma generation in the magnetospheres of neutron stars"; (3) Kosevich Yu A (N N Semenov Institute of Chemical Physics, RAS, Moscow) "Multichannel propagation and scattering of phonons and photons in low-dimension nanostructures". An abridged version of these reports is given below. • Nanoplasmonics, V V Klimov Physics-Uspekhi, 2008, Volume 51, Number 8, Pages 839-844 • Electron-positron plasma generation in the magnetospheres of neutron stars, Ya N Istomin Physics-Uspekhi, 2008, Volume 51, Number 8, Pages 844-848 • Multichannel propagation and scattering of phonons and photons in low-dimension nanostructures, Yu A Kosevich Physics-Uspekhi, 2008, Volume 51, Number 8, Pages 848-859

  12. Institute in Physical Science. A Category 1 Summer Inservice Program for Elementary and Secondary Teachers of Physical Science, Austin Metropolitan Community, Pharr-San Juan-Alamo ISD, and Region 1 Educational Service Center. Final Performance Report.

    ERIC Educational Resources Information Center

    Crawley, Frank E.

    The Institute in Physical Science was developed to address the need for updated information and training in physics, chemistry, and technology among elementary and secondary teachers of physical science. Four major objectives were addressed: (1) improve teachers' understanding of fundamental concepts in physics and chemistry; (2) improve fifth-…

  13. Measurement of Neutron Capture Cross Section of 62Ni in the keV-Region

    SciTech Connect

    Alpizar-Vicente, A. M.; Hatarik, R.; Bredeweg, T. A.; Esch, E.-I.; Haight, R. C.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Greife, U.

    2006-03-13

    The neutron capture cross section of 62Ni, relative to gold as a standard, was determined in the energy range from 250 eV to 100 keV. This energy range covers the region between 5 keV to 20 keV, which is not available in ENDF. Capture events are detected with the 160-fold 4{pi} BaF2 Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. One of the challenges was to process the high count rate of 4 MHz, which required an optimization of the data acquisition software. The neutron energy was determined by the time-of-flight technique using a flight path of 20.25 m. The sample mass of the 96% enriched 62Ni target was 210 mg and it was mounted in a 1.5 {mu}m thick Mylar foil.

  14. Charged particles produced in neutron reactions on nuclei from beryllium to gold

    SciTech Connect

    Haight, R.C.

    1997-08-01

    Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound reactions are clearly seen in the data. The data are compared with data from the literature where available, with evaluated nuclear data libraries, and with calculations where the selection of the nuclear level density prescription is of great importance. Calculations normalized at En = 14 MeV can differ from the present data by a factor of 2 for neutron energies between 5 and 10 MeV.

  15. Elastic and Inelastic Neutron Scattering with a C7LYC Array

    NASA Astrophysics Data System (ADS)

    Wilson, G. L.; Brown, T.; Chowdhury, P.; Doucet, E.; Lister, C. J.; D'Olympia, N.; Devlin, M.; Mosby, S.

    2015-10-01

    A scintillator array of 16 1'' ×1'' Cs2LiYCl6 (CLYC) detectors has been commissioned for low energy nuclear science. Standard CLYC crystals detect both gamma rays and neutrons rays with excellent pulse shape discrimination, with thermal neutrons detected via the 6Li(n, α)t reaction. Our discovery of spectroscopy-grade response of CLYC for fast neutrons via the 35Cl(n,p) reaction, with a pulse height resolution of under 10 % in the < 8 MeV range, led to our present array of 7Li enriched C7LYC detectors, where the large thermal neutron response is essentially eliminated. While the intrinsic efficiency of C7LYC for fast neutron detection is low, the array can be placed near the target since a long TOF arm is no longer needed for neutron energy measurement, thus recovering efficiency through increased solid angle coverage. The array was recently deployed at Los Alamos to test its capability in measuring differential scattering cross sections as a function of energy for 56Fe and 238U. The incident energy from a white neutron source was measured via TOF, and the scattered neutron energy via the pulse height. Techniques, analysis and first results will be discussed. Supported by the NNSA Stewardship Science Academic Alliance Program under Grant DE-NA00013008.

  16. Los Alamos National Laboratory: 21st century solutions to urgent national challenges

    SciTech Connect

    Mcbranch, Duncan

    2008-01-01

    Los Alamos National Laboratory has been called upon to meet urgent national challenges for more than 65 years. The people, tools, and technologies at Los Alamos are a world class resource that has proved decisive through our history, and are needed in the future. We offer expertise in nearly every science, technology, and engineering discipline, a unique integrated capability for large-scale computing and experimentation, and the proven ability to deliver solutions involving the most complex and difficult technical systems. This white paper outlines some emerging challenges and why the nation needs Los Alamos, the premier National Security Science Laboratory, to meet these challenges.

  17. Time-of-flight measurement of fast neutrons with Timepix detectors

    NASA Astrophysics Data System (ADS)

    Bergmann, B.; Nelson, R. O.; O'Donnell, J. M.; Pospisil, S.; Solc, J.; Takai, H.; Vykydal, Z.

    2014-05-01

    Timepix pixel detectors have been used to study the response of silicon hybrid pixel detectors to fast neutrons from a pulsed neutron beam at WNR FP30R, a 14 m long flight path, in the Los Alamos Neutron Science Center. Neutrons with kinetic energies up to 600 MeV were available. In order to enhance the conversion of neutrons to energetic charged particles, several converter foils and filters were attached to the 300 μm thick silicon sensor, i.e. polyethylene, polyethylene with aluminum, 6LiF, 6LiF with aluminum, aluminum. The Time-of-Arrival mode of the Timepix detectors has permitted the application of the Time-of-Flight (TOF) technique for the assignment of the detected interactions in the form of clusters (groups of adjacent pixels) in the pixel matrix, to the kinetic energies of the incident neutrons. It was found that, for lower neutron energies ( ~ MeV range) the cluster rates below the polyethylene and the polyethylene and aluminum region, produced by recoil protons, are a good measure for the mean kinetic energies of neutrons. For energies above 50 MeV nuclear reactions in the silicon dominate the detector response. In this energy range the shape of the clusters indicates the neutron kinetic energy.

  18. CHARACTERIZATION OF AN ADVANCED GADOLINIUM NEUTRON ABSORBER ALLOY BY MEANS OF NEUTRON TRANSMISSION

    SciTech Connect

    Gregg W. Wachs

    2007-09-01

    Neutron transmission experiments were performed on samples of an advanced nickel-chromium-molybdenum-gadolinium (Ni-Cr-Mo-Gd) neutron absorber alloy. The primary purpose of the experiments was to demonstrate the thermal neutron absorbing capability of the alloy at specific gadolinium dopant levels. The new alloy is to be deployed for criticality control of highly enriched DOE SNF. For the transmission experiments, alloy test samples were fabricated with 0.0, 1.58 and 2.1 wt% natural gadolinium dispersed in a Ni-Cr-Mo base alloy. The transmission experiments were successfully carried out at the Los Alamos Neutron Science Center (LANSCE). Measured data from the neutron transmission experiments were compared to calculated results derived from a simple exponential transmission formula using only radiative capture cross sections. Excellent agreement between the measured and calculated results demonstrated the expected strong thermal absorption capability of the gadolinium poison and in addition, verified the measured elemental composition of the alloy test samples. The good agreement also indirectly confirmed that the gadolinium was dispersed fairly uniformly in the alloy and the ENDF VII radiative capture cross section data were accurate.

  19. Los Alamos Science, Fall 1983 No. 9

    SciTech Connect

    Cooper, N G

    1983-10-01

    Topics covered in this issue include: cellular automata, gene expression, gen-bank and its promise for molecular genetics, and frontiers of supercomputing. Abstracts have been prepared for the individual items. (GHT)

  20. Neutron capture cross section of {sup 241}Am

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-15

    The neutron capture cross section of {sup 241}Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for E{sub n}<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. {gamma}{sub n} neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553{+-}7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  1. Los Alamos contribution to target diagnostics on the National Ignition Facility

    SciTech Connect

    Mack, J.M.; Baker, D.A.; Caldwell, S.E.

    1994-07-01

    The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ``phase I diagnostics.`` Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given.

  2. α and 2 p 2 n emission in fast neutron-induced reactions on 60Ni

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Devlin, M.; Haight, R. C.; Nelson, R. O.; Kunieda, S.; Kawano, T.

    2015-06-01

    Background: The cross sections for populating the residual nucleus in the reaction ZAX(n,x) Z -2 A -4Y exhibit peaks as a function of incident neutron energy corresponding to the (n ,n'α ) reaction and, at higher energy, to the (n ,2 p 3 n ) reaction. The relative magnitudes of these peaks vary with the Z of the target nucleus. Purpose: Study fast neutron-induced reactions on 60Ni. Locate experimentally the nuclear charge region along the line of stability where the cross sections for α emission and for 2 p 2 n emission in fast neutron-induced reactions are comparable as a further test of reaction models. Methods: Data were taken by using the Germanium Array for Neutron-Induced Excitations. The broad-spectrum pulsed neutron beam of the Los Alamos Neutron Science Center's Weapons Neutron Research facility provided neutrons in the energy range from 1 to 250 MeV. The time-of-flight technique was used to determine the incident-neutron energies. Results: Absolute partial cross sections for production of seven discrete Fe γ rays populated in 60Ni (n ,α /2 p x n γ ) reactions with 2 ≤x ≤5 were measured for neutron energies 1 MeVneutron energies while discrepancies appear at higher neutron energies. The cross section for producing an isotope in fast neutron-induced reactions on stable targets via α emission at the peak of the (n ,α ) and (n ,n'α ) reactions is comparable to that for 2 p 2 n and 2 p 3 n emission at higher incident energies in the nuclear charge region around Fe.

  3. RFQ development at Los Alamos

    SciTech Connect

    Wangler, T.P.; Crandall, K.R.; Stokes, R.H.

    1982-01-01

    The basic principles of the radio-frequency quadrupole (RFQ) linac are reviewed and a summary of past and present Los Alamos work is presented. Some beam-dynamics effects, important for RFQ design, are discussed. A design example is shown for xenon and a brief discussion of low-frequency RFQ structures is given.

  4. Development of a new fast neutron spectrometer using 6Li-depleted Cs2LiYCl6 scintillators

    NASA Astrophysics Data System (ADS)

    D'Olympia, Nathan W.

    A unique alternative to traditional methods of fast neutron spectroscopy was explored in this work using 6Li-depleted Cs 2LiYCl6:Ce (CLYC) scintillators. These inorganic scintillators were found to provide spectroscopic information on fast neutrons via the 35Cl(n,p)35S and 35Cl(n,alpha) 32P reactions and exhibit neutron/gamma pulse-shape discrimination. In additional to detailed characterizations of the material's response function, an array of 16 6Li-depleted CLYC detectors (C7LYC) was designed, constructed, and tested for future applications in neutron spectroscopy. Measurements of mono-energetic neutrons up to 20 MeV were carried out at the University of Kentucky and used to characterize the detector's response. Monte Carlo simulations of the response were carried out with MCNPX to investigate the various reaction mechanisms involved in the total response. Measurements of a continuous spallation neutron source with energies up to 700 MeV were carried out at the Los Alamos Neutron Science Center (LANSCE) using the time-of-flight method to measure the light output as a function of incident neutron energy and generate a detector response matrix. Spectral unfolding of C7LYC's response was investigated using the Maximum Likelihood Expectation Maximization method. The performance of the 16-detector array, SCANS, was studied to determine rate and energy dependent properties of the detectors, such as resolution, and pulse-shape discrimination, when exposed to fast neutrons and gamma-rays.

  5. Polar Maps of Thermal and Epithermal Neutrons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations by NASA's 2001 Mars Odyssey spacecraft show views of the polar regions of Mars in thermal neutrons (top) and epithermal neutrons (bottom). In these maps, deep blue indicates a low amount of neutrons, and red indicates a high amount. Thermal neutrons are sensitive to the presence of hydrogen and the presence of carbon dioxide, in this case 'dry ice' frost. The red area in the upper right map indicates that about one meter (three feet) of carbon dioxide frost covers the surface around the north pole, as it does every Mars winter in the polar regions. An enhancement of thermal neutrons close to the south pole, seen as a light green color on the upper left map, indicates the presence of residual carbon dioxide in the south polar cap, even though the annual frost dissipated from that region during southern summer. Soil enriched with hydrogen is indicated by the deep blue colors on the epithermal maps (bottom), showing a low intensity of epithermal neutrons. The deep blue areas in the polar regions are believed to contain up to 50 percent water ice in the upper one meter (three feet) of the soil. The views shown here are of measurements made during the first three months of mapping using the neutron spectrometer instrument, part of the gamma ray spectrometer instrument suite. Topographic features are superimposed on the map for geographic reference.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson, and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, is the prime

  6. Precision Neutron Polarimetry

    NASA Astrophysics Data System (ADS)

    Sharma, Monisha; Barron-Palos, L.; Bowman, J. D.; Chupp, T. E.; Crawford, C.; Danagoulian, A.; Klein, A.; Penttila, S. I.; Salas-Bacci, A. F.; Wilburn, W. S.

    2008-04-01

    Proposed PANDA and abBA experiments aim to measure the correlation coefficients in the polarized neutron beta decay at the SNS. The goal of these experiments is 0.1% measurement which will require neutron polarimetry at 0.1% level. The FnPB neutron beam will be polarized either using a ^3He spin filter or a supermirror polarizer and the neutron polarization will be measured using a ^3He spin filter. Experiment to establish the accuracy to which neutron polarization can be determined using ^3He spin fliters was performed at Los Alamos National Laboratory in Summer 2007 and the analysis is in progress. The details of the experiment and the results will be presented.

  7. Preparation of iridium targets by electrodeposition for neutron capture cross section measurements

    SciTech Connect

    Bond, Evelyn M.; Moody, W. Allen; Arnold, Charles; Bredeweg, Todd A.; Jandel, Marian; Rusev, Gencho Y.

    2015-11-18

    Here, the preparation of 191Ir and 193Ir electrodeposits for neutron capture cross-section measurements at the detector for advanced neutron capture experiments located at the at Los Alamos Neutron Science Center is described. The electrodeposition of iridium in the desired thickness of 0.4–1 mg/cm2 is challenging. Better yields and thicknesses were obtained using electrodeposition from isopropyl alcohol solutions than from ammonium sulfate solutions. 191Ir and 193Ir targets were initially prepared using the standard single-sided electrodeposition cell. Iridium electrodepositions using a double-sided electrodeposition cell were developed and were optimized, resulting in thick, uniform iridium deposits. LA UR 15-22475.

  8. Preparation of iridium targets by electrodeposition for neutron capture cross section measurements

    DOE PAGESBeta

    Bond, Evelyn M.; Moody, W. Allen; Arnold, Charles; Bredeweg, Todd A.; Jandel, Marian; Rusev, Gencho Y.

    2016-03-01

    Here, the preparation of 191Ir and 193Ir electrodeposits for neutron capture cross-section measurements at the detector for advanced neutron capture experiments located at the at Los Alamos Neutron Science Center is described. The electrodeposition of iridium in the desired thickness of 0.4–1 mg/cm2 is challenging. Better yields and thicknesses were obtained using electrodeposition from isopropyl alcohol solutions than from ammonium sulfate solutions. 191Ir and 193Ir targets were initially prepared using the standard single-sided electrodeposition cell. Iridium electrodepositions using a double-sided electrodeposition cell were developed and were optimized, resulting in thick, uniform iridium deposits. LA UR 15-22475.

  9. Analysis of the Nuclear Structure of 186 Re Using Neutron-Induced Reactions

    NASA Astrophysics Data System (ADS)

    Matters, David; McClory, John; Carroll, James; Chiara, Chris; Fotiades, Nikolaos; Devlin, Matt; Nelson, Ron O.

    2015-04-01

    Evaluated nuclear structure data for 186 Re identifies the majority of spin-parity assignments as tentative, with approximate values associated with the energies of several levels and transitions. In particular, the absence of known transitions that feed the Jπ =8+ isomer motivates their discovery, which would have astrophysical implications and a potential application in the development of an isomer power source. Using the GErmanium Array for Neutron Induced Excitations (GEANIE) spectrometer at the Los Alamos Neutron Science Center (LANSCE) Weapons Neutron Research (WNR) facility, the (n,2n γ) and (n,n' γ) reactions in a 99.52% enriched 187 Re target were used to measure γ-ray excitation functions in 186 Re and 187 Re, respectively. A preliminary analysis of the data obtained from the experiment reveals several new transitions in 186 Re and 187 Re.

  10. Preliminary neutron and X-ray crystallographic studies of equine cyanomethemoglobin

    SciTech Connect

    Kovalevsky, A.Y.; Fisher, S.Z.; Seaver, S.; Mustyakimov, M.; Sukumar, N.; Langan, P.; Mueser, T.C.; Hanson, B.L.

    2010-08-18

    Room-temperature and 100 K X-ray and room-temperature neutron diffraction data have been measured from equine cyanomethemoglobin to 1.7 {angstrom} resolution using a home source, to 1.6 {angstrom} resolution on NE-CAT at the Advanced Photon Source and to 2.0 {angstrom} resolution on the PCS at Los Alamos Neutron Science Center, respectively. The cyanomethemoglobin is in the R state and preliminary room-temperature electron and neutron scattering density maps clearly show the protonation states of potential Bohr groups. Interestingly, a water molecule that is in the vicinity of the heme group and coordinated to the distal histidine appears to be expelled from this site in the low-temperature structure.

  11. Non-Statistical Effects in Neutron Capture

    SciTech Connect

    Koehler, P. E.; Guber, K. H.; Harvey, J. A.; Wiarda, D.; Bredeweg, T. A.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Reifarth, R.

    2009-01-28

    There have been many reports of non-statistical effects in neutron-capture measurements. However, reports of deviations of reduced-neutron-width ({gamma}{sub n}{sup 0}) distributions from the expected Porter-Thomas (PT) shape largely have been ignored. Most of these deviations have been reported for odd-A nuclides. Because reliable spin (J) assignments have been absent for most resonances for such nuclides, it is possible that reported deviations from PT might be due to incorrect J assignments. We recently developed a new method for measuring spins of neutron resonances by using the DANCE detector at the Los Alamos Neutron Science Center (LANSCE). Measurements made with a {sup 147}Sm sample allowed us to determine spins of almost all known resonances below 1 keV. Furthermore, analysis of these data revealed that the {gamma}{sub n}{sup 0} distribution was in good agreement with PT for resonances below 350 eV, but in disagreement with PT for resonances between 350 and 700 eV. Our previous (n,{alpha}) measurements had revealed that the {alpha} strength function also changes abruptly at this energy. There currently is no known explanation for these two non-statistical effects. Recently, we have developed another new method for determining the spins of neutron resonances. To implement this technique required a small change (to record pulse-height information for coincidence events) to a much simpler apparatus: A pair of C{sub 6}D{sub 6}{gamma}-ray detectors which we have employed for many years to measure neutron-capture cross sections at the Oak Ridge Electron Linear Accelerator (ORELA). Measurements with a {sup 95}Mo sample revealed that not only does the method work very well for determining spins, but it also makes possible parity assignments. Taken together, these new techniques at LANSCE and ORELA could be very useful for further elucidation of non-statistical effects.

  12. Non-Statistical Effects in Neutron Capture

    SciTech Connect

    Koehler, Paul Edward; Bredeweg, t a; Guber, Klaus H; Harvey, John A; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wiarda, Dorothea; Wouters, J. M.

    2009-01-01

    There have been many reports of non-statistical effects in neutron-capture measurements. However, reports of deviations of reduced-neutron-width ({Gamma}n{sup 0}) distributions from the expected Porter-Thomas (PT) shape largely have been ignored. Most of these deviations have been reported for odd-A nuclides. Because reliable spin (J) assignments have been absent for most resonances for such nuclides, it is possible that reported deviations from PT might be due to incorrect J assignments. We recently developed a new method for measuring spins of neutron resonances by using the DANCE detector at the Los Alamos Neutron Science Center (LANSCE). Measurements made with a 147Sm sample allowed us to determine spins of almost all known resonances below 1 keV. Furthermore, analysis of these data revealed that the {Gamma}n{sup 0} distribution was in good agreement with PT for resonances below 350 eV, but in disagreement with PT for resonances between 350 and 700 eV. Our previous (n,{alpha}) measurements had revealed that the {alpha} strength function also changes abruptly at this energy. There currently is no known explanation for these two non-statistical effects. Recently, we have developed another new method for determining the spins of neutron resonances. To implement this technique required a small change (to record pulse-height information for coincidence events) to a much simpler apparatus: A pair of C6D6 ?-ray detectors which we have employed for many years to measure neutron-capture cross sections at the Oak Ridge Electron Linear Accelerator (ORELA). Measurements with a 95Mo sample revealed that not only does the method work very well for determining spins, but it also makes possible parity assignments. Taken together, these new techniques at LANSCE and ORELA could be very useful for further elucidation of non-statistical effects.

  13. A Search for Exotic Spin-Dependent Interactions of the Neutron using Neutron Spin Rotation

    NASA Astrophysics Data System (ADS)

    Haddock, Chris; Nsr Collaboration

    2016-03-01

    Many theories beyond the Standard Model lead at low energy to spin-dependent, weakly-coupled interactions of mesoscopic range. Laboratory constraints on such interactions are quite poor. We describe an experiment in progress at the LANSCE spallation neutron source at Los Alamos to search for exotic axial couplings of neutrons to matter from light vector boson exchange. The experiment makes use of a slow neutron polarimeter and a target with an oscillating mass density. Neutron Spin Rotation.

  14. High-energy response of the PRESCILA and WENDI-II neutron rem meters.

    PubMed

    Olsher, Richard H; McLean, Thomas D

    2008-01-01

    WENDI-II was designed at the Los Alamos National Laboratory (LANL) specifically as a wide-range rem meter, suitable for applications at particle accelerators, with response extension to 5 GeV. PRESCILA was also designed at LANL, mainly as a lightweight alternative to traditional rem meters, but has shown excellent response characteristics above 20 MeV. This Note summarises measurements performed over a span of 4 y to characterise the high-energy neutron response (>20 MeV) of these meters to several hundred million electron volts. High-energy quasi-monoenergetic beams utilised as part of this study were produced by the cyclotron facilities at the Université Catholique de Louvain (33 and 60 MeV) and the T. Svedberg Laboratory ( 46, 95, 143 and 173 MeV). In addition, measurements were also conducted at the Los Alamos Neutron Science Center, 800 MeV spallation neutron source, in broad energy fields with an average energy of 345 MeV. For the sake of completeness, data collected between 2.5 and 19 MeV in monoenergetic neutron fields at the German Physikalisch-Technische Bundesanstalt (PTB) facility are also included in this study. PMID:18381335

  15. RFQ development at Los Alamos

    SciTech Connect

    Armstrong, D.D.; Cornelius, W.D.; Purser, F.O.; Jameson, R.A.; Wangler, T.P.

    1984-01-01

    We report recent progress on the two radio-frequency quadrupole (RFQ) structures being developed at Los Alamos. First, we report on the second 425-MHz RFQ for H/sup -/ acceleration, which is being built in a research effort to understand and further develop the RFQ. Second, we discuss progress on the 80-MHz cw RFQ for deuterons, which is being built for the Fusion Materials Irradiation Test (FMIT) facility.

  16. HEIMDAL: A thermal neutron powder diffractometer with high and flexible resolution combined with SANS and neutron imaging - Designed for materials science studies at the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Holm, Sonja L.; Lefmann, Kim; Henry, Paul F.; Bertelsen, Mads; Schefer, Jürg; Christensen, Mogens

    2016-08-01

    HEIMDAL will be a multi length scale neutron scattering instrument for the study of structures covering almost nine orders of magnitude from 0.01 nm to 50 mm. The instrument is accepted for construction at the European Spallation Source (ESS) and features a variable resolution thermal neutron powder diffractometer (TNPD), combined with small angle neutron scattering (SANS) and neutron imaging (NI). The instrument uses a novel combination of a cold and a thermal guide to fulfill the diverse requirements for diffraction and SANS. With an instrument length of 170 m, HEIMDAL will take advantage of the high neutron flux of the long pulse at ESS, whilst maintaining a high q-resolution due to the long flight path. The q-range coverage is up to 20 Å-1 allowing low-resolution PDF analysis. With the addition of SANS, HEIMDAL will be able to cover a uniquely broad length scale within a single instrumental set-up. HEIMDAL will be able to accommodate modern materials research in a broad variety of fields, and the task of the instrument will be to study advanced functional materials in action, as in situ and in operandi at multiple length scales (0.01-100 nm) quasi simultaneously. The instrument combines state-of-the-art neutron scattering techniques (TNPD, SANS, and NI) with the goal of studying real materials, in real time, under real conditions. This article describes the instrument design ideas, calculations and results of simulations and virtual experiments.

  17. Nuclear-accident dosimetry: measurements at the Los Alamos SHEBA critical assembly

    SciTech Connect

    Vasilik, D.G.; Martin, R.W.; Fuller, D.

    1981-07-01

    Criticality dosimeters were exposed to different degraded neutron and gamma-ray energy spectra from the Los Alamos Solution High Energy Burst Assembly (SHEBA). The liquid critical test assembly was operated in the continuous mode to provide a mixed source of neutron and gamma-ray radiation for the evaluation of Los Alamos criticality detector systems. Different neutron and gamma-ray spectra were generated by operating the reactor (a) shielded by 12 cm of Lucite, (b) unshielded, (c) shielded by 20 cm of concrete, and (d) shielded by 15 cm of steel. This report summarizes the dosimetry measurements conducted for these different configurations. In-air measurements were conducted with shielded and unshielded area and personnel dosimeters. Phantom measurements were made using personnel dosimeters. Combined blood-sodium and hair sulfur activation measurements of absorbed dose were also made. In addition, indium foils placed on phantoms were evaluated for the purpose of screening personnel for radiation exposure.

  18. Using spallation neutron sources for defense research

    SciTech Connect

    Pynn, R.; Sterbenz, S.M.; Weinacht, D.J.

    1996-12-31

    Advanced characterization techniques and accelerated simulation are the cornerstones of the Energy Department`s science-based program to maintain confidence in the safety, reliability, and performance of the US nuclear deterrent in an era of no nuclear testing. Neutrons and protons provided by an accelerator-based facility have an important role to play in this program, impacting several of the key stockpile stewardship and management issues identified by the Department of Defense. Many of the techniques used for defense research at a spallation source have been used for many years for the basic research community, and to a lesser extent by industrial scientists. By providing access to a broad spectrum of researchers with different backgrounds, a spallation source such as the Los Alamos Neutron Science Center is able to promote synergistic interaction between defense, basic and industrial researchers. This broadens the scientific basis of the stockpile stewardship program in the short term and will provide spin-off to industrial and basic research in the longer term.

  19. Precision Polarization of Neutrons

    NASA Astrophysics Data System (ADS)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  20. Neutron filters for producing monoenergetic neutron beams

    SciTech Connect

    Harvey, J.A.; Hill, N.W.; Harvey, J.R.

    1982-01-01

    Neutron transmission measurements have been made on high-purity, highly-enriched samples of /sup 58/Ni (99.9%), /sup 60/Ni (99.7%), /sup 64/Zn (97.9%) and /sup 184/W (94.5%) to measure their neutron windows and to assess their potential usefulness for producing monoenergetic beams of intermediate energies from a reactor. Transmission measurements on the Los Alamos Sc filter (44.26 cm Sc and 1.0 cm Ti) have been made to determine the characteristics of the transmitted neutron beam and to measure the total cross section of Sc at the 2.0 keV minimum. When corrected for the Ti and impurities, a value of 0.35 +- 0.03 b was obtained for this minimum.

  1. Review of Livermore-Led Neutron Capture Studies Using DANCE

    SciTech Connect

    Parker, W; Sheets, S; Agvaanluvsan, U; Becker, J; Becvar, F; Bredeweg, T; Clement, R; Couture, A; Esch, E; Haight, R; Jandel, M; Krticka, M; Mitchell, G; Macri, R; O'Donnell, J; Reifarth, R; Rundberg, R; Schwantes, J; Ullmann, J; Vieira, D; Wouters, J; Wilk, P

    2007-05-11

    We have made neutron capture cross-section measurements using the white neutron source at the Los Alamos Science Center, the DANCE detector array (Detector for Advanced Neutron Capture Experiments) and targets important for basic science and stockpile stewardship. In this paper, we review results from (n,{gamma}) reactions on {sup 94,95}Mo, {sup 152,154,157,160,nat}Gd, {sup 151,153}Eu and {sup 242m}Am for neutron energies from < 1eV up to {approx} 20 keV. We measured details of the {gamma}-ray cascade following neutron capture, for comparison with results of statistical model simulations. We determined the neutron energy dependent (n,{gamma}) cross section and gained information about statistical decay properties, including the nuclear level density and the photon strength function. Because of the high granularity of the detector array, it is possible to look at gamma cascades with a specified number of transitions (a specific multiplicity). We simulated {gamma}-ray cascades using a combination of the DICEBOX/GEANT computer codes. In the case of the deformed nuclei, we found evidence of a scissors-mode resonance. For the Eu, we also determined the (n,{gamma}) cross sections. For the {sup 94,95}Mo, we focused on the spin and parity assignments of the resonances and the determination of the photon strength functions for the compound nuclei {sup 95,96}Mo. Future plans include measurements on actinide targets; our immediate interest is in {sup 242m}Am.

  2. Application of neutron diffraction in characterization of texture evolution during high-temperature creep in magnesium alloys

    SciTech Connect

    Vogel, Sven C; Sediako, Dimitry; Shook, S; Sediako, A

    2010-01-01

    A good combination of room-temperature and elevated temperature strength and ductility, good salt-spray corrosion resistance and exceUent diecastability are frequently among the main considerations in development of a new alloy. Unfortunately, there has been much lesser effort in development of wrought-stock alloys for high temperature applications. Extrudability and high temperature performance of wrought material becomes an important factor in an effort to develop new wrought alloys and processing technologies. This paper shows some results received in creep testing and studies of in-creep texture evolution for several wrought magnesium alloys developed for use in elevated-temperature applications. These studies were performed using E3 neutron spectrometer of the Canadian Neutron Beam Centre in Chalk River, ON, and HIPPO time-of-flight (TOF) spectrometer at Los Alamos Neutron Science Center, NM.

  3. Small-Angle Neutron Scattering (SANS) Facility at BATAN for Nanostructure Studies in Materials Science and Biology

    NASA Astrophysics Data System (ADS)

    Putra, E. Giri Rachman

    2010-01-01

    A 36 meter small-angle neutron scattering (SANS) BATAN spectrometer (SMARTer) which is the second largest SANS spectrometer nowadays in the Asia-Oceania region was constructed at the neutron scattering laboratory (NSL) in Serpong, Indonesia. Lots of works on replacing, upgrading and improving the control system, experimental methods, data collection and reduction in the last three years have been carried out to revitalize and then optimize the performance of SMARTer. At first, some standard samples were measured for the inter-laboratory comparison and several kinds of substances such as liquid, gel, powder, and solid-state thin film have been investigated recently of proposed research interest. The morphological changes from ellipsoidal into cylindrical (worm-like) micelles of self-assembly amphiphilic molecules, sodium dodecyl sulfate (SDS) and transformation of disordered into ordered spherical micelle system from unimer Gaussian coils of PEO-PPO-PEO triblock copolymers (Pluronics) in solution by salt addition were also observed. Particle size and its distribution of spherical polystyrene latex and silica nanoparticles in dilute solution have been simply distinguished by applying a spherical calculation model. Bragg peaks which correspond to a lamellar structure was revealed from a powder sample of silver behenate [CH3(CH2)20COOAg] nanoparticle and a solid-state PS-PEP, polystyrene-b-poly(ethylene-alt-propylene), diblock copolymer film. The growth mechanism and fractal structures from aggregation of nanoparticles such as Fe3O4 ferrofluids or titanium-silica aerogels were investigated directly using a SANS technique through a power-law scattering of fractal structures approximation fitted at their scattering profiles. Meanwhile, magnetic structure from metal-alloys, CuNiFe showing anisotropic magnetic scattering structure properties up to 1 Tesla of external magnetic field was also accomplished confirming the nanocrystalline and magnetic domain sizes. The detail

  4. Operational comparison of bubble (super heated drop) dosimetry with routine albedo TLD for a selected group of Pu-238 workers at Los Alamos National Laboratory

    SciTech Connect

    Romero, L.L.; Hoffman, J.M.; Foltyn, E.M.; Buhl, T.E.

    1998-09-01

    Personnel neutron dosimetry continues to be a difficult science due to the lack of availability of robust passive dosimeters that exhibit tissue- or near-tissue- equivalent response. This paper is an operational study that compares the use of albedo thermoluminescent dosimeters with bubble dosimeters to determine whether bubble dosimeters do provide a useful daily ALARA tool that can yield measurements close to the dose-of-record. A group of workers at Los Alamos National Laboratory (LANL) working on the Radioisotopic Thermoelectric Generators (RTG) for the NASA Cassini space mission wore both bubble dosimeters and albedo dosimeters over a period from 1993 through 1996. The personal albedo dosimeter was processed on a monthly basis and used as the dose-of-record. The results of this study indicated that cumulative daily bubble dosimetry results agreed with whole-body albedo dosimetry results within about 37% on average.

  5. Gamma-Ray Emission Spectra as a Constraint on Calculations of 234 , 236 , 238U Neutron-Capture Cross Sections

    NASA Astrophysics Data System (ADS)

    Ullmann, J. L.; Krticka, M.; Kawano, T.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Haight, R. C.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Wu, C. Y.; Chyzh, A.

    2015-10-01

    Calculations of the neutron-capture cross section at low neutron energies (10 eV through 100's of keV) are very sensitive to the nuclear level density and radiative strength function. These quantities are often poorly known, especially for radioactive targets, and actual measurements of the capture cross section are usually required. An additional constraint on the calculation of the capture cross section is provided by measurements of the cascade gamma spectrum following neutron capture. Recent measurements of 234 , 236 , 238U(n, γ) emission spectra made using the DANCE 4 π BaF2 array at the Los Alamos Neutron Science Center will be presented. Calculations of gamma-ray spectra made using the DICEBOX code and of the capture cross section made using the CoH3 code will also be presented. These techniques may be also useful for calculations of more unstable nuclides. This work was performed with the support of the U.S. Department of Energy, National Nuclear Security Administration by Los Alamos National Security, LLC (Contract DE-AC52-06NA25396) and Lawrence Livermore National Security, LLC (Contract DE-AC52-07NA2734).

  6. High Speed Data Acquisition System for Three-Dimensional X-Ray and Neutron Computed Tomography

    SciTech Connect

    Davis, A.W.; Claytor, T.N.; Sheats, M.J.

    1999-07-01

    Computed tomography for nondestructive evaluation applications has been limited by system cost, resolution, and time requirements for three-dimensional data sets. FlashCT (Flat panel Amorphous Silicon High-Resolution Computed Tomography) is a system developed at Los Alamos National Laboratory to address these three problems. Developed around a flat panel amorphous silicon detector array, FlashCT is suitable for low to medium energy x-ray and neutron computed tomography at 127-micron resolution. Overall system size is small, allowing rapid transportation to a variety of radiographic sources. System control software was developed in LabVIEW for Windows NT to allow multithreading of data acquisition, data correction, and staging motor control. The system control software simplifies data collection and allows fully automated control of the data acquisition process, leading toward remote or unattended operation. The first generation of the FlashCT Data Acquisition System was completed in Au gust 1998, and since that time the system has been tested using x-ray sources ranging in energy from 60 kV to 20MV. The system has also been used to collect data for thermal neutron computed tomography at Los Alamos Neutron Science Center (LANSCE). System improvements have been proposed to provide faster data collection and greater dynamic range during data collection.

  7. Testing Monte Carlo Simulations for Neutron Scattering in MoNA

    NASA Astrophysics Data System (ADS)

    Hamann, A.; Garrett, S.; Seagren, T.; Taylor, N. E.; Rogers, W. F.; MoNA Collaboration

    2015-10-01

    Monte Carlo simulations provide an important tool for nuclear physics research, both in preparing for experiments, and in interpreting experimental data. The Modular Neutron Array (MoNA) and the Large area multi-Institutional Scintillator Array (LISA) are used in conjunction with the Sweeper Magnet and charged particle detector chamber at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University to study the properties of exotic, neutron-rich nuclei. We use simulations to model our BC408 scintillator detectors and extract physics results from experimental data. We have developed specific simulations in preparation for an experiment we will conduct at the Los Alamos Neutron Science Center (LANSCE), where we will direct a well-defined neutron beam onto a cluster of 16 MoNA detector bars and observe the scattering patterns of single neutrons. Simulations enable us to study the predicted light output generated by individual neutron scattering channels from Carbon and Hydrogen. The data we will generate in the LANSCE experiment will provide a large experimental database with which to test the reliability of our simulations. This is important since our understanding of nuclei far from stability is becoming increasingly reliant on simulations. this work supported by NSF Grants PHY-1101745 and PHY-1506402.

  8. Cross section measurements at LANSCE for defense, science and applications

    SciTech Connect

    Nelson, Ronald O.; Schwengner, R.; Zuber, K.

    2015-05-28

    The Los Alamos Neutron Science Center (LANSCE) has three neutron sources that are used for nuclear science measurements. These sources are driven by an 800 MeV proton linear accelerator and cover an energy range from sub-thermal to hundreds of MeV. Research at the facilities is performed under the auspices of a US DOE user program under which research proposals are rated for merit by a program advisory committee and are scheduled based on merit and availability of beam time. A wide variety of instruments is operated at the neutron flight paths at LANSCE including neutron detector arrays, gamma-ray detector arrays, fission fragment detectors, and charged particle detectors. These instruments provide nuclear data for multiple uses that range from increasing knowledge in fundamental science to satisfying data needs for diverse applications such as nuclear energy, global security, and industrial applications. In addition, highlights of recent research related to cross sections measurements are presented, and future research initiatives are discussed.

  9. Cross section measurements at LANSCE for defense, science and applications

    DOE PAGESBeta

    Nelson, Ronald O.; Schwengner, R.; Zuber, K.

    2015-05-28

    The Los Alamos Neutron Science Center (LANSCE) has three neutron sources that are used for nuclear science measurements. These sources are driven by an 800 MeV proton linear accelerator and cover an energy range from sub-thermal to hundreds of MeV. Research at the facilities is performed under the auspices of a US DOE user program under which research proposals are rated for merit by a program advisory committee and are scheduled based on merit and availability of beam time. A wide variety of instruments is operated at the neutron flight paths at LANSCE including neutron detector arrays, gamma-ray detector arrays,more » fission fragment detectors, and charged particle detectors. These instruments provide nuclear data for multiple uses that range from increasing knowledge in fundamental science to satisfying data needs for diverse applications such as nuclear energy, global security, and industrial applications. In addition, highlights of recent research related to cross sections measurements are presented, and future research initiatives are discussed.« less

  10. The performance of the Los Alamos Proton Storage Ring

    SciTech Connect

    Lawrence, G.P.

    1987-03-01

    The Proton Storage Ring (PSR) now in operation at Los Alamos is a high-current accumulator that generates intense 800-MeV proton pulses for driving the Los Alamos Neutron Scattering Center (LANSCE) spallation source. The ring compresses up to 1000-..mu..s-long macropulses from the LAMPF linac into 250-ns bunches and ejects them to a neutron-production target, providing an output optimized for thermal-neutron-scattering research. The design pulse rate and peak pulse intensity of PSR are 12 Hz and 5.2 . 10/sup 13/ protons per pulse (ppp), yielding 100 ..mu..A average current when full performance is reached. This paper summarizes commissioning results and operational experience in the two years since first beam. The PSR has operated in production at average currents up to 30 ..mu..A and has reached a peak intensity of 3.4 . 10/sup 13/ ppp. These achievements represents 30% and 65% of the design objectives. Higher current production has been inhibited by beam losses during accumulation and extraction. Therefore, experiments to understand loss mechanisms have occupied a large fraction of the commissioning effort. Correction of an extraction-channel aperture restriction identified late in 1986 should dramatically reduce extraction losses, which will permit higher current production in 1987. Beam tests in the 10/sup 13/-ppp range have indicated the presence of a collective instability tentatively identified as transverse. However, by suitable parameter adjustments, the instability threshold can be pushed above the top charge-level attainable with the existing H /sup -/ source.

  11. Time-of-flight neutron diffraction study of bovine [gamma]-chymotrypsin at the Protein Crystallography Station

    SciTech Connect

    Lazar, Louis M.; Fisher, S. Zoe; Moulin, Aaron G.; Kovalevsky, Andrey; Novak, Walter R.P.; Langan, Paul; Petsko, Gregory A.; Ringe, Dagmar

    2012-02-06

    The overarching goal of this research project is to determine, for a subset of proteins, exact hydrogen positions using neutron diffraction, thereby improving H-atom placement in proteins so that they may be better used in various computational methods that are critically dependent upon said placement. In order to be considered applicable for neutron diffraction studies, the protein of choice must be amenable to ultrahigh-resolution X-ray crystallography, be able to form large crystals (1 mm{sup 3} or greater) and have a modestly sized unit cell (no dimension longer than 100 {angstrom}). As such, {gamma}-chymotrypsin is a perfect candidate for neutron diffraction. To understand and probe the role of specific active-site residues and hydrogen-bonding patterns in {gamma}-chymotrypsin, neutron diffraction studies were initiated at the Protein Crystallography Station (PCS) at Los Alamos Neutron Science Center (LANSCE). A large single crystal was subjected to H/D exchange prior to data collection. Time-of-flight neutron diffraction data were collected to 2.0 {angstrom} resolution at the PCS with 85% completeness. Here, the first time-of-flight neutron data collection from {gamma}-chymotrypsin is reported.

  12. Feeding of isomers of stable Rh, Ag, Ir and Au isotopes in fast-neutron-induced reactions

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Devlin, M.; Nelson, R. O.; Carroll, J. J.

    2016-03-01

    The GEANIE spectrometer, comprised of 20 high-purity Ge detectors coupled to the broad-spectrum pulsed neutron beam of the Los Alamos Neutron Science Center's (LANSCE) WNR facility, has been used to determine partial γ-ray cross sections in (n , xn) fast-neutron-induced reactions. In (n ,n') reactions on stable Ir and Au isotopes the γ-ray feeding, as established with GEANIE, for the isomers relative to the feeding of the corresponding ground states increases with increasing neutron energy up to the neutron energy where the (n , 2 n) reaction channel opens and then decreases. The behavior in mass A = 100 region of the γ-ray feeding of isomers and ground states was also studied with GEANIE in fast-neutron-induced reactions on stable Rh and Ag isotopes. The feeding of the isomers was found to be very similar in the corresponding reaction channels and it was compared to the feeding determined for the ground states. The opening of higher-neutron-emitting reaction channels remove angular momentum from the compound system and reduce the population of higher-spin isomers relative to the feeding of lower-spin ground states in all cases studied.

  13. Overview of laser technology at Los Alamos National Laboratory

    NASA Astrophysics Data System (ADS)

    Lewis, G. K.; Cremers, D. A.

    Los Alamos National Laboratory has had a long history of involvement in laser sciences and has been recognized both for its large laser programs and smaller scale developments in laser technology and applications. The first significant program was with the Rover nuclear-based rocket propulsion system in 1968 to study laser initiated fusion. From here applications spread to programs in laser isotope separation and development of large lasers for fusion. These programs established the technological human resource base of highly trained laser physicists, engineers, and chemists that remain at the Laboratory today. Almost every technical division at Los Alamos now has some laser capability ranging from laser development, applications, studies on nonlinear processes, modeling and materials processing. During the past six years over eight R&D-100 Awards have been received by Los Alamos for development of laser-based techniques and instrumentation. Outstanding examples of technology developed include LIDAR applications to environmental monitoring, single molecule detection using fluorescence spectroscopy, a laser-based high kinetic energy source of oxygen atoms produced by a laser-sustained plasma, laser-induced breakdown spectroscopy (LIBS) for compositional, analysis, thin film high temperature superconductor deposition, multi-station laser welding, and direct metal deposition and build-up of components by fusing powder particles with a laser beam.

  14. Overview of laser technology at Los Alamos National Laboratory

    SciTech Connect

    Lewis, G.K.; Cremers, D.A.

    1994-09-01

    Los Alamos National Laboratory has had a long history of involvement in laser sciences and has been recognized both for its large laser programs and smaller scale developments in laser technology and applications. The first significant program was with the Rover nuclear-based rocket propulsion system in 1968 to study laser initiated fusion. From here applications spread to programs in laser isotope separation and development of large lasers for fusion. These programs established the technological human resource base of highly trained laser physicists, engineers, and chemists that remain at the Laboratory today. Almost every technical division at Los Alamos now has some laser capability ranging from laser development, applications, studies on nonlinear processes, modeling and materials processing. During the past six years over eight R&D-100 Awards have been received by Los Alamos for development of laser-based techniques and instrumentation. Outstanding examples of technology developed include LIDAR applications to environmental monitoring, single molecule detection using fluorescence spectroscopy, a laser-based high kinetic energy source of oxygen atoms produced by a laser-sustained plasma, laser-induced breakdown spectroscopy (LIBS) for compositional, analysis, thin film high temperature superconductor deposition, multi-station laser welding, and direct metal deposition and build-up of components by fusing powder particles with a laser beam.

  15. Fundamental neutron physics at LANSCE

    SciTech Connect

    Greene, G.

    1995-10-01

    Modern neutron sources and science share a common origin in mid-20th-century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for studying condensed matter with modern neutron sources being primarily used (and justified) as tools for neutron scattering and materials science research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities performed at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high-flux neutron facilities. Future sources, particularly high-power spallation sources, offer exciting possibilities for continuing this research.

  16. Los Alamos PC estimating system

    SciTech Connect

    Stutz, R.A.; Lemon, G.D.

    1987-01-01

    The Los Alamos Cost Estimating System (QUEST) is being converted to run on IBM personal computers. This very extensive estimating system is capable of supporting cost estimators from many different and varied fields. QUEST does not dictate any fixed method for estimating. QUEST supports many styles and levels of detail estimating. QUEST can be used with or without data bases. This system allows the estimator to provide reports based on levels of detail defined by combining work breakdown structures. QUEST provides a set of tools for doing any type of estimate without forcing the estimator to use any given method. The level of detail in the estimate can be mixed based on the amount of information known about different parts of the project. The system can support many different data bases simultaneously. Estimators can modify any cost in any data base.

  17. Water Mass Map from Neutron Spectrometer

    NASA Technical Reports Server (NTRS)

    2003-01-01

    December 8, 2003

    This map shows the estimated lower limit of the water content of the upper meter of Martian soil. The estimates are derived from the hydrogen abundance measured by the neutron spectrometer component of the gamma ray spectrometer suite on NASA's Mars Odyssey spacecraft.

    The highest water-mass fractions, exceeding 30 percent to well over 60 percent, are in the polar regions, beyond about 60 degrees latitude north or south. Farther from the poles, significant concentrations are in the area bound in longitude by minus 10 degrees to 50 degrees and in latitude by 30 degrees south to 40 degrees north, and in an area to the south and west of Olympus Mons (30 degrees to 0 degrees south latitude and minus 135 degrees to 110 degrees longitude).

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for the NASA Office of Space Science in Washington. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Space Systems, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL.

  18. Gamma-ray isotopic analysis development at Los Alamos

    SciTech Connect

    Thomas E. Sampson

    1999-11-01

    This report describes the development history and characteristics of software developed in the Safeguards Science and Technology group at Los Alamos for gamma-ray isotopic analysis. This software analyzes the gamma-ray spectrum from measurements performed on actinide samples (principally plutonium and uranium) of arbitrary size, geometry, and physical and chemical composition. The results are obtained without calibration using only fundamental tabulated nuclear constants. Characteristics of the current software versions are discussed in some detail and many examples of implemented measurement systems are shown.

  19. Los Alamos National Laboratory capability reviews - FY 2011 status

    SciTech Connect

    Springer, Everett P

    2011-01-12

    Capability reviews are the Los Alamos National Laboratory approach to assess the quality of its science, technology, and engineering (STE), and its integration across the Laboratory. There are seven capability reviews in FY 2011 reviews. The Weapons Science and Engineering review will be replaced by the National Nuclear Security Administration's Predictive Science Panel for 2011 . Beginning in 2011, third-year LORD projects will be reviewed by capability review committees rather than the first-year LORD projects that have been performed for the last three years. This change addresses concerns from committees about reviewing a project before it had made any substantive progress. The current schedule, and chairs for the 2011 capability reviews is presented. The three-year cycle (2011-2013) for capability reviews are presented for planning purposes.

  20. Los Alamos National Laboratory Training Capabilities (Possible Applications in the Global Initiatives for Proliferation Prevention Program)

    SciTech Connect

    Martin, Olga

    2012-06-04

    The briefing provides an overview of the training capabilities at Los Alamos National Laboratory that can be applied to nonproliferation/responsible science education at nuclear institutes in the Former Soviet Union, as part of the programmatic effort under the Global Initiatives for Proliferation Prevention program (GIPP).

  1. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  2. World's Largest Gold Crystal Studied at Los Alamos

    ScienceCinema

    Vogel, Sven; Nakotte, Heinz

    2015-01-07

    When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

  3. World's Largest Gold Crystal Studied at Los Alamos

    SciTech Connect

    Vogel, Sven; Nakotte, Heinz

    2014-04-03

    When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

  4. Neutron Capture Experiments on Unstable Nuclei

    SciTech Connect

    Schwantes, Jon M.; Sudowe, Ralf; Folden, Charles M., III; Nitsche, Heino; Hoffman, Darleane C.

    2005-01-15

    The overall objective of this project is the measurement of neutron capture cross sections of importance to stewardship science and astrophysical modeling of nucleosynthesis, while at the same time helping to train the next generation of scientists with expertise relevant to U.S. national nuclear security missions and to stewardship science. A primary objective of this project is to study neutron capture cross sections for various stable and unstable isotopes that will contribute to the Science Based Stockpile Stewardship (SBSS) program by providing improved data for modeling and interpretation of nuclear device performance. Much of the information obtained will also be important in astrophysical modeling of nucleosynthesis. Measurements of these neutron capture cross sections are being conducted in collaboration with researchers at the Los Alamos Neutron Science Center (LANSCE) facility using the unique Detector for Advanced Neutron Capture Experiments (DANCE). In our early discussions with the DANCE group, decisions were made on the first cross sections to be measured and how our expertise in target preparation, radiochemical separations chemistry, and data analysis could best be applied. The initial emphasis of the project was on preparing suitable targets of both natural and separated stable europium isotopes in preparation for the ultimate goal of preparing a sufficiently large target of radioactive 155Eu (t1/2 = 4.7 years) and other radioactive and stable species for neutron cross-section measurements at DANCE. Our Annual Report, ''Neutron Capture Experiments on Unstable Nuclei'' by J. M. Schwantes, R. Sudowe, C. M. Folden III, H. Nitsche, and D. C. Hoffman, submitted to NNSA in December 2003, gives details about the initial considerations and scope of the project. During the current reporting period, electroplated targets of natural Eu together with valuable, stable, and isotopically pure 151Eu and 153Eu, and isotopically separated 154Sm were measured for

  5. Time gating for energy selection and scatter rejection: High-energy pulsed neutron imaging at LANSCE

    NASA Astrophysics Data System (ADS)

    Swift, Alicia; Schirato, Richard; McKigney, Edward; Hunter, James; Temple, Brian

    2015-09-01

    The Los Alamos Neutron Science Center (LANSCE) is a linear accelerator in Los Alamos, New Mexico that accelerates a proton beam to 800 MeV, which then produces spallation neutron beams. Flight path FP15R uses a tungsten target to generate neutrons of energy ranging from several hundred keV to ~600 MeV. The beam structure has micropulses of sub-ns width and period of 1.784 ns, and macropulses of 625 μs width and frequency of either 50 Hz or 100 Hz. This corresponds to 347 micropulses per macropulse, or 1.74 x 104 micropulses per second when operating at 50 Hz. Using a very fast, cooled ICCD camera (Princeton Instruments PI-Max 4), gated images of various objects were obtained on FP15R in January 2015. Objects imaged included blocks of lead and borated polyethylene; a tungsten sphere; and a tungsten, polyethylene, and steel cylinder. Images were obtained in 36 min or less, with some in as little as 6 min. This is novel because the gate widths (some as narrow as 10 ns) were selected to reject scatter and other signal not of interest (e.g. the gamma flash that precedes the neutron pulse), which has not been demonstrated at energies above 14 MeV. This proof-of-principle experiment shows that time gating is possible above 14MeV and is useful for selecting neutron energy and reducing scatter, thus forming clearer images. Future work (simulation and experimental) is being undertaken to improve camera shielding and system design and to precisely determine optical properties of the imaging system.

  6. Sunset at the ALaMO

    NASA Video Gallery

    A new color all-sky camera has opened its eyes at the ALaMO, or Automated Lunar and Meteor Observatory, at NASA's Marshall Space Flight Center in Huntsville, Ala. Watch its inaugural video below, s...

  7. Environmental surveillance at Los Alamos during 1994

    SciTech Connect

    1996-07-01

    This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance.

  8. New Rad Lab for Los Alamos

    ScienceCinema

    None

    2010-01-08

    The topping out ceremony for a key construction stage in the Los Alamos National Laboratory's newest facility, the Radiological Laboratory Utility & Office Building. This is part of the National Nu...  

  9. Publications of Los Alamos research 1988

    SciTech Connect

    Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A.

    1989-12-01

    This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.

  10. New Rad Lab for Los Alamos

    SciTech Connect

    2008-08-06

    The topping out ceremony for a key construction stage in the Los Alamos National Laboratory's newest facility, the Radiological Laboratory Utility & Office Building. This is part of the National Nu...  

  11. International workshop on cold neutron sources

    SciTech Connect

    Russell, G.J.; West, C.D. )

    1991-08-01

    The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

  12. Internship at Los Alamos National Laboratory

    SciTech Connect

    Dunham, Ryan Q.

    2012-07-11

    Los Alamos National Laboratory (LANL) is located in Los Alamos, New Mexico. It provides support for our country's nuclear weapon stockpile as well as many other scientific research projects. I am an Undergraduate Student Intern in the Systems Design and Analysis group within the Nuclear Nonproliferation division of the Global Security directorate at LANL. I have been tasked with data analysis and modeling of particles in a fluidized bed system for the capture of carbon dioxide from power plant flue gas.

  13. Science policy in changing times

    SciTech Connect

    Greenwood, M.R.C.

    1995-10-01

    Like many scientists who were born right after World War II and who have learned a lot about physics, physical sciences, and biology from some of the incredible discoveries that were made in the defense laboratories, I have always been fascinated with Los Alamos. One of the marvelous opportunities that my job in Washington presented was to get to know a good deal more about the physical science world and the Department of Energy (DOE) laboratories, particularly Los Alamos since the Manhattan Project.

  14. Absolute measurement of the 242Pu neutron-capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  15. Monte Carlo Simulations of the Response of Shielded SNM to a Pulsed Neutron Source

    SciTech Connect

    E.H. Seabury; D.L. Chichester

    2010-08-01

    Active interrogation (AI) has been used as a technique for the detection and identification of Special Nuclear Material (SNM) for both proposed and field-tested systems. Idaho National Laboratory (INL) has been studying this technique for systems ranging from small systems employing portable electronic neutron generators (ENGs) 1 to larger systems employing linear accelerators as high-energy photon sources for assessment of vehicles and cargo2. In order to assess the feasibility of new systems, INL has undertaken a campaign of Monte Carlo simulations of the response of a variety of masses of SNM in multiple shielding configurations to a pulsed neutron source using the MCNPX3 code, with emphasis on the neutron and photon response of the system as a function of time after the initial neutron pulse. We present here some preliminary results from these calculations. 1. D.L. Chichester and E.H. Seabury, “ Using Electronic Neutron Generators in Active Interrogation to Detect Shielded Nuclear Material,” IEEE Transactions on Nuclear Science 56 (2009) pp 441-447. 2. J.L. Jones et al., “Photonuclear-based, nuclear material detection system for cargo containers,” Nuclear Instruments and Methods in Physics Research B 241 (2005) pp 770-776. 3. D.B. Pelowitz, “MCNPXTM User’s Manual version 2.6.0,” Los Alamos National Laboratory Report LA-CP-07-1473 (2008).

  16. Absolute measurement of the 242Pu neutron-capture cross section

    DOE PAGESBeta

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; et al

    2016-04-21

    Here, the absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n,γ) cross section was made over the incident neutron energy range from thermal to ≈ 6 keV, and the absolute scale of the (n,γ) cross section was set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the crossmore » section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈ 40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n,γ) cross section at the En,R = 2.68 eV resonance is within 2.4% of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30% lower than the evaluated data at En ≈ 1 keV and are approximately 2σ away from the previous measurement at En ≈ 20 keV.« less

  17. DANCEing with the Stars: Measuring Neutron Capture on Unstable Isotopes with DANCE

    SciTech Connect

    Couture, A.; Bond, E.; Bredeweg, T. A.; Fowler, M.; Haight, R. C.; Jandel, M.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Agvaanluvsan, U.; Becker, J. A.; Baker, J. D.; Bayarbadrahk, B.; Chyzh, A.; Dashdorj, D.; Reifarth, R.

    2009-03-10

    Isotopes heavier than iron are known to be produced in stars through neutron capture processes. Two major processes, the slow (s) and rapid (r) processes are each responsible for 50% of the abundances of the heavy isotopes. The neutron capture cross sections of the isotopes on the s process path reveal information about the expected abundances of the elements as well as stellar conditions and dynamics. Until recently, measurements on unstable isotopes, which are most important for determining stellar temperatures and reaction flow, have not been experimentally feasible. The Detector for Advance Neutron Capture Experiments (DANCE) located at the Los Alamos Neutron Science Center (LANSCE) was designed to perform time-of-flight neutron capture measurements on unstable isotopes for nuclear astrophysics, stockpile stewardship, and reactor development. DANCE is a 4-{pi}BaF{sub 2} scintillator array which can perform measurements on sub-milligram samples of isotopes with half-lives as short as a few hundred days. These cross sections are critical for advancing our understanding of the production of the heavy isotopes.

  18. Preliminary time-of-flight neutron diffraction study of human deoxyhemoglobin

    SciTech Connect

    Kovalevsky, A. Y.; Chatake, T.; Shibayama, N.; Park, S.-Y.; Ishikawa, T.; Mustyakimov, M.; Fisher, S. Z.; Langan, P.; Morimoto, Y.

    2008-04-01

    In order to investigate the role of the protonation states of protein residues in O{sub 2} binding, large crystals of deoxy HbA (∼20 mm{sup 3}) were grown in D{sub 2}O under anaerobic conditions for neutron diffraction studies. Human hemoglobin (HbA) is an intricate system that has evolved to efficiently transport oxygen molecules (O{sub 2}) from lung to tissue. Its quaternary structure can fluctuate between two conformations, T (tense or deoxy) and R (relaxed or oxy), which have low and high affinity for O{sub 2}, respectively. The binding of O{sub 2} to the heme sites of HbA is regulated by protons and by inorganic anions. In order to investigate the role of the protonation states of protein residues in O{sub 2} binding, large crystals of deoxy HbA (∼20 mm{sup 3}) were grown in D{sub 2}O under anaerobic conditions for neutron diffraction studies. A time-of-flight neutron data set was collected to 1.8 Å resolution on the Protein Crystallography Station (PCS) at the spallation source run by Los Alamos Neutron Science Center (LANSCE). The HbA tetramer (64.6 kDa; 574 residues excluding the four heme groups) occupies the largest asymmetric unit (space group P2{sub 1}) from which a high-resolution neutron data set has been collected to date.

  19. Advantages and limitations of nuclear physics experiments at an ISIS-class spallation neutron source

    NASA Astrophysics Data System (ADS)

    Mocko, M.; Muhrer, G.; Tovesson, F.

    2008-05-01

    Nuclear physics experiments have a long history of being conducted on spallation neutron sources. Like other experiments, these measurements take advantage of the identification of the incident neutron energy by the time-of-flight (ToF) technique. However, in some ways these experiments are often in direct conflict with other experiments. Especially in large (ISIS or SNS class) facilities, the design of the source often reflects a compromise between different experimental needs and requirements. It has been a long standing question for nuclear physics experiments how limiting these compromises are and how they can be dealt with. We have therefore calculated the incident neutron energy spectrum, along with the gamma background spectrum, for flight path (FP) 5 at the Los Alamos Neutron Science Center (LANSCE) Manuel Lujan Jr. Neutron Scattering Center (Lujan Center) including a detailed evaluation of the signal shape. We will discuss the advantages and limitations of the nuclear physics experiments at FP-5 in the light of our results.

  20. Los Alamos Laser Eye Investigation.

    SciTech Connect

    Odom, C. R.

    2005-01-01

    A student working in a laser laboratory at Los Alamos National Laboratory sustained a serious retinal injury to her left eye when she attempted to view suspended particles in a partially evacuated target chamber. The principle investigator was using the white light from the flash lamp of a Class 4 Nd:YAG laser to illuminate the particles. Since the Q-switch was thought to be disabled at the time of the accident, the principal investigator assumed it would be safe to view the particles without wearing laser eye protection. The Laboratory Director appointed a team to investigate the accident and to report back to him the events and conditions leading up to the accident, equipment malfunctions, safety management causal factors, supervisory and management action/inaction, adequacy of institutional processes and procedures, emergency and notification response, effectiveness of corrective actions and lessons learned from previous similar events, and recommendations for human and institutional safety improvements. The team interviewed personnel, reviewed documents, and characterized systems and conditions in the laser laboratory during an intense six week investigation. The team determined that the direct and primary failures leading to this accident were, respectively, the principle investigator's unsafe work practices and the institution's inadequate monitoring of worker performance. This paper describes the details of the investigation, the human and institutional failures, and the recommendations for improving the laser safety program.

  1. Prompt Fission Neutron Energy Spectra Induced by Fast Neutrons

    NASA Astrophysics Data System (ADS)

    Staples, Parrish Alan

    Prompt fission neutron energy spectra for ^{235}U and ^{239 }Pu have been measured for fission neutron energies greater than the energy of the incident neutrons inducing fission. The measurements were undertaken to investigate the shape dependence of the fission neutron spectra upon both the incident neutron energy and the mass of the nucleus undergoing fission. Measurements were made for both nuclides at the following incident neutron energies; 0.50 MeV, 1.50 MeV, 2.50 MeV and 3.50 MeV. The data are presented either as relative yields or as ratios of a measured spectrum to the ^{235}U spectrum at 0.50 MeV. Incident neutrons were produced by the ^7Li(p,n)^7Be reaction using a pulsed, bunched proton beam from the 5.5 MV Van de Graaff accelerator at the University of Massachusetts Lowell Pinanski Energy Center. The neutrons were detected by a thin liquid scintillator with good time resolution capabilities; time-of-flight techniques were used for neutron energy determination; in addition pulse-shape-discrimination was used to reduce gamma-ray background levels. The measurements are compared to calculations based on the Los Alamos Model of Madland and Nix to test its predictive capabilities. The data are fit by the Watt equation to determine the mean energy of the spectra, and to facilitate comparison of the results to previous measurements. The data are also compared directly to previous measurements.

  2. Micro-focused Small Angle Neutron Scattering and Imaging for Science and Engineering Using RTP—A Preliminary Study

    NASA Astrophysics Data System (ADS)

    Mohamed, Abdul Aziz; Al Rashid Megat Ahmad, Megat Harun; Md Idris, Faridah; Azman, Azraf; Jamro, Rafhayudi; Ibrahim, Mohd Rizal Mamat; Rahman, Anwar Abdul

    2010-01-01

    Malaysian Nuclear Agency's (Nuclear Malaysia) Small Angle Neutron Scattering (SANS) facility—(MYSANS)—is utilizing low flux of thermal neutron at the agency's 1 MW TRIGA reactor. As the design nature of the 8 m SANS facility can allow object resolution in the range between 5 and 80 nm to be obtained. It can be used to study alloys, ceramics and polymers in certain area of problems that relate to samples containing strong scatterers or contrast. The current SANS system at Malaysian Nuclear Agency is only capable to measure Q in limited range with a PSD (128×128) fixed at 4 m from the sample. The existing reactor hall that incorporate this MYSANS facility has a layout that prohibits the rebuilding of MYSANS therefore the position between the wavelength selector (HOPG) and sample and the PSD cannot be increased for wider Q range. The flux of the neutron at current sample holder is very low which around 103 n/cm2/sec. Thus it is important to rebuild the MYSANS to maximize the utilization of neutron. Over the years, the facility has undergone maintenance and some changes have been made. Modification on secondary shutter and control has been carried out to improve the safety level of the instrument. A compact micro-focus SANS method can suit this objective together with an improve cryostat system. This paper will explain some design concept and approaches in achieving higher flux and the modification needs to establish the micro-focused SANS.

  3. Micro-focused Small Angle Neutron Scattering and Imaging for Science and Engineering Using RTP--A Preliminary Study

    SciTech Connect

    Mohamed, Abdul Aziz; Al Rashid Megat Ahmad, Megat Harun; Md Idris, Faridah; Azman, Azraf; Jamro, Rafhayudi; Ibrahim, Mohd Rizal Mamat; Rahman, Anwar Abdul

    2010-01-05

    Malaysian Nuclear Agency's (Nuclear Malaysia) Small Angle Neutron Scattering (SANS) facility--(MYSANS)--is utilizing low flux of thermal neutron at the agency's 1 MW TRIGA reactor. As the design nature of the 8 m SANS facility can allow object resolution in the range between 5 and 80 nm to be obtained. It can be used to study alloys, ceramics and polymers in certain area of problems that relate to samples containing strong scatterers or contrast. The current SANS system at Malaysian Nuclear Agency is only capable to measure Q in limited range with a PSD (128x128) fixed at 4 m from the sample. The existing reactor hall that incorporate this MYSANS facility has a layout that prohibits the rebuilding of MYSANS therefore the position between the wavelength selector (HOPG) and sample and the PSD cannot be increased for wider Q range. The flux of the neutron at current sample holder is very low which around 10{sup 3} n/cm{sup 2}/sec. Thus it is important to rebuild the MYSANS to maximize the utilization of neutron. Over the years, the facility has undergone maintenance and some changes have been made. Modification on secondary shutter and control has been carried out to improve the safety level of the instrument. A compact micro-focus SANS method can suit this objective together with an improve cryostat system. This paper will explain some design concept and approaches in achieving higher flux and the modification needs to establish the micro-focused SANS.

  4. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    SciTech Connect

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-12-01

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants.

  5. Science.

    ERIC Educational Resources Information Center

    Roach, Linda E., Ed.

    This document contains the following papers on science instruction and technology: "A 3-D Journey in Space: A New Visual Cognitive Adventure" (Yoav Yair, Rachel Mintz, and Shai Litvak); "Using Collaborative Inquiry and Interactive Technologies in an Environmental Science Project for Middle School Teachers: A Description and Analysis" (Patricia…

  6. Gamma Ray/neutron Spectrometers for Planetary Elemental Mapping

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Auchampaugh, G. F.; Barraclough, B. L.; Burt, W. W.; Byrd, R. C.; Drake, D. M.; Edwards, B. C.; Feldman, W. C.; Martin, R. A.; Moss, C. E.

    1993-01-01

    Los Alamos has designed gamma ray and neutron spectrometers for Lunar Scout, two robotic missions to map the Moon from 100 km polar orbits. Knowledge of the elemental composition is desirable in identifying resources and for geochemical studies and can be obtained using gamma ray and neutron spectrometers. Measurements with gamma ray and neutron spectrometers complement each other in determining elemental abundances in a planet's surface. Various aspects of the instruments are discussed.

  7. Towards an advanced hadron facility at Los Alamos

    NASA Astrophysics Data System (ADS)

    Thiessen, Henry A.

    1988-11-01

    In the 1987 AHF Workshop, it was pointed out that activation of the accelerator is a serious problem. At this workshop, it was suggested that a new type of slow extraction system is needed to reduce the activation. We report on the response to this need. The Los Alamos plan is reviewed including as elements the long lead-time R&D in preparation for a 1993 construction start, a menu of accelerator designs, improved losses at injection and extraction time, active participation in the development of PSR, an accelerated hardware R&D program, and close collaboration with TRIUMF. We review progress on magnets and power supplies, on ceramic vacuum chambers, and on ferrite-tuned rf systems. We report on the plan for a joint TRIUMF-Los Alamos main-ring cavity to be tested in PSR in 1989. The problem of beam losses is discussed in detail and a recommendation for a design procedure for the injection system is made. This recommendation includes taking account of single Coulomb scattering, a painting scheme for minimizing foil hits, and a collimator and dump system for containing the expected spills. The slow extraction problem is reviewed and progress on an improved design is discussed. The problem of designing the accelerators for minimum operation and maintenance cost is briefly discussed. The question of the specifications for an advanced hadron facility is raised and it is suggested that the Los Alamos Proposal of a dual energy machine—1.6 GeV and 60 GeV—is a better match to the needs of the science program than the single-energy proposals made elsewhere. It is suggested that design changes need be made in all of the world's hadron facility proposals to prepare for high-intensity operation.

  8. FY07 LDRD Final Report Neutron Capture Cross-Section Measurements at DANCE

    SciTech Connect

    Parker, W; Agvaanluvsan, U; Wilk, P; Becker, J; Wang, T

    2008-02-08

    We have measured neutron capture cross sections intended to address defense science problems including mix and the Quantification of Margins and Uncertainties (QMU), and provide details about statistical decay of excited nuclei. A major part of this project included developing the ability to produce radioactive targets. The cross-section measurements were made using the white neutron source at the Los Alamos Neutron Science Center, the detector array called DANCE (The Detector for Advanced Neutron Capture Experiments) and targets important for astrophysics and stockpile stewardship. DANCE is at the leading edge of neutron capture physics and represents a major leap forward in capability. The detector array was recently built with LDRD money. Our measurements are a significant part of the early results from the new experimental DANCE facility. Neutron capture reactions are important for basic nuclear science, including astrophysics and the statistics of the {gamma}-ray cascades, and for applied science, including stockpile science and technology. We were most interested in neutron capture with neutron energies in the range between 1 eV and a few hundred keV, with targets important to basic science, and the s-process in particular. Of particular interest were neutron capture cross-section measurements of rare isotopes, especially radioactive isotopes. A strong collaboration between universities and Los Alamos due to the Academic Alliance was in place at the start of our project. Our project gave Livermore leverage in focusing on Livermore interests. The Lawrence Livermore Laboratory did not have a resident expert in cross-section measurements; this project allowed us to develop this expertise. For many radionuclides, the cross sections for destruction, especially (n,{gamma}), are not well known, and there is no adequate model that describes neutron capture. The modeling problem is significant because, at low energies where capture reactions are important, the neutron

  9. New Generation of Los Alamos Opacity Tables

    NASA Astrophysics Data System (ADS)

    Colgan, James; Kilcrease, D. P.; Magee, N. H.; Sherrill, M. E.; Abdallah, J.; Hakel, P.; Fontes, C. J.; Guzik, J. A.; Mussack, K. A.

    2016-05-01

    We present a new generation of Los Alamos OPLIB opacity tables that have been computed using the ATOMIC code. Our tables have been calculated for all 30 elements from hydrogen through zinc and are publicly available through our website. In this poster we discuss the details of the calculations that underpin the new opacity tables. We also show several recent applications of the use of our opacity tables to solar modeling and other astrophysical applications. In particular, we demonstrate that use of the new opacities improves the agreement between solar models and helioseismology, but does not fully resolve the long-standing `solar abundance' problem. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

  10. Publications of Los Alamos Research, 1983

    SciTech Connect

    Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L.

    1984-10-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  11. Publications of Los Alamos research 1980

    SciTech Connect

    Salazar, C.A.; Willis, J.K.

    1981-09-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1980. Papers published in 1980 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted-even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was pubished more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-laboratory reports, journal articles, books, chapters of books, conference papers published either separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  12. SEDs at Los Alamos: A Personal Memoir

    NASA Astrophysics Data System (ADS)

    Bederson, Benjamin

    2001-03-01

    I have written this personal memoir approximately 55 years after the events I describe. It is based almost exclusively on memory, since apart from the diary I kept while on Tinian, I have few documents concerning it. It covers my service in the U.S. Army's Special Engineering Detachment (SED) in Oak Ridge and Los Alamos in 1944-45, on Tinian island, the launching pad for the bombing raids on Japan, in the summer and fall of 1945, and my return to Los Alamos until my discharge in January 1946.

  13. Upper Los Alamos canyon fact sheet

    SciTech Connect

    Berger, Jeffrey H

    2007-01-01

    Los Alamos National Laboratory is planning to make environmental assessments in portions of Upper Los Alamos Canyon. Upper Los Alamos Canyon is one of the areas included in the 2005 Consent Order agreed to by Los Alamos National Laboratory, the National Nuclear Security Administration, and the New Mexico Environment Department. As such, it must be evaluated for potential contamination. The area is located within and south of the Los Alamos townsite in Technical Areas 00, 01, 03, 32, 41, 43, and 61 of Los Alamos National Laboratory and includes a total of 115 solid waste management units and areas of concern. This area was home to some of the earliest operations at Los Alamos, dating from the 1940s. Of the 115 solid-waste management units and areas of concern, 54 have been addressed previously. The remaining 61 are the focus of this project. These include septic tanks and outfalls, sanitary and industrial waste lines, storm drains, soil contamination areas, landfill and surface disposal areas, transformer sites, and incinerators. The Consent Order requires the Laboratory to evaluate historical work sites for the potential presence of residual contamination. It also requires the Laboratory to identify and implement corrective actions should contamination be found. The Laboratory began performing these types of activities in the 1990s. The Upper Los Alamos Canyon project entails: (1) collecting soil and rock samples using the most efficient and least-invasive methods practicable; (2) defining the nature and extent of any residual contamination associated with each solid waste management unit or area of concern; and (3) gathering additional data if needed to evaluate potential remedial alternatives. A variety of methods, including studies of engineering drawings, nonintrusive geophysical surveys, and trenching, may be used to identify the final sampling locations. The field team then determines which collection method to use at each location, based on such site

  14. Plutonium 238 facilities at Los Alamos

    NASA Astrophysics Data System (ADS)

    Rinehart, Gary H.

    1991-01-01

    Plutonium 238 operations at Los Alamos are performed at the Plutonium Facility (TA-55), the Chemistry and Metallurgy Research (CMR) Building, and the Radioisotope Fuels Impact Test Facility. The plutonium 238 facilities at Los Alamos support a wide variety of heat source activities including development of new fuel forms and containment materials, research on the high temperature properties of containment materials, investigation of the high temperature compatibility of fuels with potential container materials, processing plutonium 238 fuel forms, manufacture of heat sources under quality assurance surveillance, and performing safety testing on heat sources and radioisotope thermoelectric generators.

  15. Plutonium-238 facilities at Los Alamos

    NASA Astrophysics Data System (ADS)

    Rinehart, Gary H.

    Plutonium-238 operations at Los Alamos are performed at the Plutonium Facility (TA-55), the Chemistry and Metallurgy Research (CMR) Building, and the Radioisotope Fuels Impact Test Facility. The plutonium-238 facilities at Los Alamos support a wide variety of heat source activities including development of new fuel forms and containment materials, research on the high temperature properties of containment materials, investigation of the high temperature compatibility of fuels with potential container materials, processing plutonium-238 fuel forms, manufacture of heat sources under quality assurance surveillance, and performing safety testing on heat sources and radioisotope thermoelectric generators.

  16. Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)

    SciTech Connect

    Salmon, M.; Goen, L.K.

    1995-12-01

    The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper.

  17. Neutron Imaging and Applications

    SciTech Connect

    Anderson, Ian S; McGreevy, Robert L; Bilheux, Hassina Z

    2009-04-01

    Neutron Imaging and Applications offers an introduction to the basics of neutron beam production and instrumentation in addition to the wide scope of techniques that provide unique imaging capabilities over a broad and diverse range of applications. An instructional overview of neutron sources, optics and detectors, allows readers to delve more deeply into the discussions of radiography, tomography, phase contrast imaging and prospective applications using advanced neutron holography techniques and polarized beams. A section devoted to overviews in a growing range of applications describes imaging of fuel cells and hydrogen storage devices for a robust hydrogen economy; new directions in material science and engineering; the investigation of precious artifacts of cultural heritage importance; determination of plant physiology and growth processes; imaging of biological tissues and macromolecules, and the practical elements of neutron imaging for homeland security and contraband detection. Written by key experts in the field, researchers and engineers involved with imaging technologies will find Neutron Imaging and Applications a valuable reference.

  18. Preparation of a one-curie 171Tm target for the Detector for Advanced Neutron Capture Experiments (DANCE)

    SciTech Connect

    Schwantes, Jon M.; Taylor, Wayne A.; Rundberg, Robert S.; Vieira, David J.

    2008-05-15

    Roughly one curie of 171Tm (t1/2=1.92a) has been produced and purified for the purpose of making a nuclear target for the first measurements of its neutron capture cross section. Target preparation consisted of three key steps: (1) material production; (2) separation and purification; and (3) electrodeposition onto a suitable backing material. Approximately 1.5 mg of the target material (at the time of separation) was produced by irradiating roughly 250 mg of its stable enriched 170Er lanthanide neighbor with neutrons at the ILL reactor in France. This production method resulted in a “difficult-to-separate” 1:167 mixture of near-neighboring lanthanides, Tm and Er. Separation and purification was accomplished using high-performance liquid chromatorgraphy (HPLC), with a proprietary cation exchange column (Dionex, CS-3) and alpha-hydroxyisobutyric acid (a-HIB) eluent. This technique yielded a final product of ~95% purity with respect to Tm. A portion (20 ug) of the Tm was electrodeposited on thin Be foil and delivered to the Los Alamos Neutron Science CEnter (LANSCE) for preliminary analysis of its neutron capture cross section using the Detector for Advanced Neutron Capture Experiments (DANCE). This paper discusses the major hurdles associated with the separation and purification step including, scale-up issues related to the use of HPLC for material separation and purification of the target material from a-HIB and 4-(2-pyridylazo)resorcinol (PAR) colorant.

  19. Rationale for a spallation neutron source target system test facility at the 1-MW Long-Pulse Spallation Source

    SciTech Connect

    Sommer, W.F.

    1995-12-01

    The conceptual design study for a 1-MW Long-Pulse Spallation Source at the Los Alamos Neutron Science Center has shown the feasibility of including a spallation neutron test facility at a relatively low cost. This document presents a rationale for developing such a test bed. Currently, neutron scattering facilities operate at a maximum power of 0.2 MW. Proposed new designs call for power levels as high as 10 MW, and future transmutation activities may require as much as 200 MW. A test bed will allow assessment of target neutronics; thermal hydraulics; remote handling; mechanical structure; corrosion in aqueous, non-aqueous, liquid metal, and molten salt systems; thermal shock on systems and system components; and materials for target systems. Reliable data in these areas are crucial to the safe and reliable operation of new high-power facilities. These tests will provide data useful not only to spallation neutron sources proposed or under development, but also to other projects in accelerator-driven transmutation technologies such as the production of tritium.

  20. Reducing Uncertainties in Neutron-Induced Fission Cross Sections Using a Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Manning, Brett; Niffte Collaboration

    2015-10-01

    Neutron-induced fission cross sections for actinides have long been of great interest for nuclear energy and stockpile stewardship. Traditionally, measurements were performed using fission chambers which provided limited information about the detected fission events. For the case of 239Pu(n,f), sensitivity studies have shown a need for more precise measurements. Recently the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) has developed the fission Time Projection Chamber (fissionTPC) to measure fission cross sections to better than 1% uncertainty by providing 3D tracking of fission fragments. The fissionTPC collected data to calculate the 239Pu(n,f) cross section at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center during the 2014 run cycle. Preliminary analysis has been focused on studying particle identification and target and beam non-uniformities to reduce the uncertainty on the cross section. Additionally, the collaboration is investigating other systematic errors that could not be well studied with a traditional fission chamber. LA-UR-15-24906.

  1. Neutron coincidence imaging for active and passive neutron assays

    SciTech Connect

    Estep, R. J.; Brunson, G. S.; Melton, S. G.

    2001-01-01

    Neutron multiplicity assay algorithms for {sup 240}Pu assume a point source of fission neutrons that are detected in a single detector channel. The {sup 240}Pu in real waste, however, is more likely to be distributed throughout the container in some random way. For different reasons, this leads to significant errors when using either multiplicity or simpler coincidence analyses. Reduction of these errors can be achieved using tomographic imaging. In this talk we report on our results from using neutron singles and coincidence data between tagged detector pairs to provide enhanced tomographic imaging capabilities to a crate nondestructive assay system. Only simulated passive coincidence data is examined here, although the higher signal rates from active coincidence counting hold more promise for waste management. The active coincidence approach has significantly better sensitivity than the passive and is not significantly perturbed by (alpha,n) contributions. Our study was based primarily on simulated neutron pulse trains derived from the Los Alamos SIM3D software, which were subjected to analysis using the Los Alamos CTEN-FIT and TGS-FIT software. We found significantly improved imaging capability using the coincidence and singles rate data than could be obtained using the singles rate alone.

  2. Cross-Section Measurements for Proton- and Neutron-Induced Reactions Needed to Understand Cosmic-Ray Interactions on Earth and in Space

    NASA Astrophysics Data System (ADS)

    Sisterson, Janet M.

    2005-05-01

    Primary cosmic rays interact directly with extraterrestrial bodies and cosmic-ray shower particles interact with the earth's surface to produce small quantities of radionuclides and stable isotopes, which are measured routinely using appropriate techniques. Theoretical models are used to analyze these measurements to learn the history of the object or the cosmic rays that fell upon it. Cross sections for reactions producing these cosmogenic nuclides are essential input to these models. Most primary cosmic rays are protons, and good measurements of the cross sections for proton-induced reactions are essential. Most relevant cross sections are now well measured, but discrepancies still exist between the measurements and calculations. One explanation is that neutrons produced in primary cosmic-ray interactions also initiate spallation reactions contributing significantly to the cosmogenic nuclide inventory, but few of the relevant cross sections have been measured at energies >30 MeV. We have measured many of these needed cross sections for neutron-induced reactions using two different techniques. Cross sections at selected unique neutron energies >70 MeV are measured at iThemba LABS, South Africa (iTL) using quasi-monoenergetic neutron beams. Energy integrated (average) cross sections are measured at the Los Alamos Neutron Science Center (LANSCE), using `white' neutron beams with an energy range of 0.1-750 MeV.

  3. Proceedings of the Los Alamos neutrino workshop

    SciTech Connect

    Boehm, F.; Stephenson, G.J. Jr.

    1982-08-01

    A workshop on neutrino physics was held at Los Alamos from June 8 to 12, 1981. The material presented has been provided in part by the organizers, in part by the chairmen of the working sessions. Closing date for contributions was October 1981.

  4. Induction inserts at the Los Alamos PSR

    SciTech Connect

    King-Yuen Ng

    2002-09-30

    Ferrite-loaded induction tuners installed in the Los Alamos Proton Storage Ring have been successful in compensating space-charge effects. However, the resistive part of the ferrite introduces unacceptable microwave instability and severe bunch lengthening. An effective cure was found by heating the ferrite cores up to {approx} 130 C. An understanding of the instability and cure is presented.

  5. Los Alamos Fires From Landsat 7

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 9, 2000, the Landsat 7 satellite acquired an image of the area around Los Alamos, New Mexico. The Landsat 7 satellite acquired this image from 427 miles in space through its sensor called the Enhanced Thematic Mapper Plus (ETM+). Evident within the imagery is a view of the ongoing Cerro Grande fire near the town of Los Alamos and the Los Alamos National Laboratory. Combining the high-resolution (30 meters per pixel in this scene) imaging capacity of ETM+ with its multi-spectral capabilities allows scientists to penetrate the smoke plume and see the structure of the fire on the surface. Notice the high-level of detail in the infrared image (bottom), in which burn scars are clearly distinguished from the hotter smoldering and flaming parts of the fire. Within this image pair several features are clearly visible, including the Cerro Grande fire and smoke plume, the town of Los Alamos, the Los Alamos National Laboratory and associated property, and Cerro Grande peak. Combining ETM+ channels 7, 4, and 2 (one visible and two infrared channels) results in a false color image where vegetation appears as bright to dark green (bottom image). Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. The areas recently burned appear black. Dark red to bright red patches, or linear features within the burned area, are the hottest and possibly actively burning areas of the fire. The fire is spreading downslope and the front of the fire is readily detectable about 2 kilometers to the west and south of Los Alamos. Combining ETM+ channels 3, 2, and 1 provides a true-color image of the greater Los Alamos region (top image). Vegetation is generally dark to medium green. Forested areas are very dark green

  6. Los Alamos Discovers Super Efficient Solar Using Perovskite Crystals

    SciTech Connect

    Mohite, Aditya; Nie, Wanyi

    2015-01-29

    State-of-the-art photovoltaics using high-purity, large-area, wafer-scale single-crystalline semiconductors grown by sophisticated, high temperature crystal-growth processes offer promising routes for developing low-cost, solar-based clean global energy solutions for the future. Solar cells composed of the recently discovered material organic-inorganic perovskites offer the efficiency of silicon, yet suffer from a variety of deficiencies limiting the commercial viability of perovskite photovoltaic technology. In research to appear in Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that eliminates these limitations, one that allows for the growth of high-quality, large-area, millimeter-scale perovskite crystals and demonstrates that highly efficient and reproducible solar cells with reduced trap assisted recombination can be realized.

  7. Active neutron multiplicity analysis and Monte Carlo calculations

    NASA Astrophysics Data System (ADS)

    Krick, M. S.; Ensslin, N.; Langner, D. G.; Miller, M. C.; Siebelist, R.; Stewart, J. E.; Ceo, R. N.; May, P. K.; Collins, L. L., Jr.

    Active neutron multiplicity measurements of high-enrichment uranium metal and oxide samples have been made at Los Alamos and Y-12. The data from the measurements of standards at Los Alamos were analyzed to obtain values for neutron multiplication and source-sample coupling. These results are compared to equivalent results obtained from Monte Carlo calculations. An approximate relationship between coupling and multiplication is derived and used to correct doubles rates for multiplication and coupling. The utility of singles counting for uranium samples is also examined.

  8. Comparison of graphite, aluminum, and TransHab shielding material characteristics in a high-energy neutron field

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Huff, H.; Wilkins, R.; Thibeault, Sheila

    2002-01-01

    Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal energy spectra with graphite, aluminum, and a TransHab build-up as shielding, was carried out at the Los Alamos Nuclear Science Center neutron facility. It is a continuation of a previous study using regolith and doped polyethylene materials. This paper describes the results and their comparison with the previous study. Published by Elsevier Science Ltd.

  9. Los Alamos National Security, LLC Request for Information from industrial entities that desire to commercialize Laboratory-developed Extremely Low Resource Optical Identifier (ELROI) tech

    SciTech Connect

    Erickson, Michael Charles

    2015-11-10

    Los Alamos National Security, LLC (LANS) is the manager and operator of the Los Alamos National Laboratory for the U.S. Department of Energy National Nuclear Security Administration under contract DE-AC52-06NA25396. LANS is a mission-centric Federally Funded Research and Development Center focused on solving the most critical national security challenges through science and engineering for both government and private customers.

  10. Integrating the digital library puzzle: The library without walls at Los Alamos

    SciTech Connect

    Luce, R. E.

    1998-01-01

    Current efforts at the Research Library, Los Alamos National Laboratory (LANL), to develop digital library services are described. A key principle of LANL`s approach to delivering library information is the integration of products into a common interface and the use of the Web as the medium of service provision. Products described include science databases such as the SciSearch at LANL and electronic journals. Project developments described have significant ramifications for delivering library services over the Internet.

  11. Atmospheres of Quiescent Low-Mass Neutron Stars

    NASA Astrophysics Data System (ADS)

    Karpov, Platon; Medin, Zachary; Calder, Alan; Lattimer, James M.

    2016-01-01

    Observations of the neutron stars in quiescent low-mass X-ray binaries are important for determining their masses and radii which can lead to powerful constraints on the dense matter nuclear equation of state. The interpretation of these sources is complex and their spectra differ appreciably from blackbodies. Further progress hinges on reducing the uncertainties stemming from models of neutron star atmospheres. We present a suite of low-temperature neutron star atmospheres of different chemical compositions (pure H and He). Our models are constructed over a range of temperatures [log(T/1 K)=5.3, 5.6, 5.9, 6.2, 6.5] and surface gravities [log(g/1 cm/s2)=14.0, 14.2, 14.4, 14.6]. We generated model atmospheres using zcode - a radiation transfer code developed at Los Alamos National Laboratory. In order to facilitate analytic studies, we developed three-parameter fits to our models, and also compared them to diluted blackbodies in the energy range of 0.4-5 keV (CXO/MGE). From the latter, we extract color-correction factors (fc), which represent the shift of the spectra as compared to a blackbody with the same effective temperature. These diluted blackbodies are also useful for studies of photspheric expansion X-ray bursts. We provide a comparison of our models to previous calculations using the McGill Planar Hydrogen Atmosphere Code (McPHAC). These results enhance our ability to interpret thermal emission from neutron stars and to constrain the mass-radius relationship of these exotic objects.This research was supported in part by the U.S. Department of Energy under grant DE-FG02-87ER40317 and by resources at the Institute for Advanced Computational Science at Stony Brook University. This research was carried out in part under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory and supported by Contract No. DE-AC52-06NA25396.

  12. Neutron scattering instrumentation for biology at spallation neutron sources

    SciTech Connect

    Pynn, R.

    1994-12-31

    Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. In fact, the current generation of pulsed spallation neutron sources, such as LANSCE at Los Alamos and ISIS in the United Kingdom, has demonstrated a capability for small angle scattering (SANS) - a typical cold- neutron application - that was not anticipated five years ago. Although no one has yet built a Laue diffractometer at a pulsed spallation source, calculations show that such an instrument would provide an exceptional capability for protein crystallography at one of the existing high-power spoliation sources. Even more exciting is the prospect of installing such spectrometers either at a next-generation, short-pulse spallation source or at a long-pulse spallation source. A recent Los Alamos study has shown that a one-megawatt, short-pulse source, which is an order of magnitude more powerful than LANSCE, could be built with today`s technology. In Europe, a preconceptual design study for a five-megawatt source is under way. Although such short-pulse sources are likely to be the wave of the future, they may not be necessary for some applications - such as Laue diffraction - which can be performed very well at a long-pulse spoliation source. Recently, it has been argued by Mezei that a facility that combines a short-pulse spallation source similar to LANSCE, with a one-megawatt, long-pulse spallation source would provide a cost-effective solution to the global shortage of neutrons for research. The basis for this assertion as well as the performance of some existing neutron spectrometers at short-pulse sources will be examined in this presentation.

  13. A Los Alamos concept for accelerator transmutation of waste and energy production (ATW)

    SciTech Connect

    Not Available

    1990-12-31

    This document contains the diagrams presented at the ATW (Accelerator Transmutation of Waste and Energy Production) External Review, December 10-12, 1990, held at Los Alamos National Laboratory. Included are the charge to the committee and the presentations for the committee`s review. Topics of the presentations included an overview of the concept, LINAC technology, near-term application -- high-level defense wastes (intense thermal neutron source, chemistry and materials), advanced application of the ATW concept -- fission energy without a high-level waste stream (overview, advanced technology, and advanced chemistry), and a summary of the research issues.

  14. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.; Babcock, Dale F.; Menegus, Robert L.

    1983-01-01

    A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

  15. Plastic fiber scintillator response to fast neutrons

    NASA Astrophysics Data System (ADS)

    Danly, C. R.; Sjue, S.; Wilde, C. H.; Merrill, F. E.; Haight, R. C.

    2014-11-01

    The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented.

  16. Plastic fiber scintillator response to fast neutrons

    SciTech Connect

    Danly, C. R.; Sjue, S.; Wilde, C. H.; Merrill, F. E.; Haight, R. C.

    2014-11-15

    The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented.

  17. Science Explorers Translation Project.

    ERIC Educational Resources Information Center

    Jacobs, Dolores

    This paper describes a pilot project of Los Alamos National Laboratory (New Mexico) to translate a science education curriculum for junior and senior high school students into Navajo. The project consisted of translating a video, a teacher's guide, and an interactive multimedia product on the 1993 hantavirus outbreak in the Four Corners area…

  18. Pulsed spallation Neutron Sources

    SciTech Connect

    Carpenter, J.M.

    1994-12-31

    This paper reviews the early history of pulsed spallation neutron source development at Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provides a few examples of applications in fundamental condensed matter physics, materials science and technology.

  19. Pulsed spallation neutron sources

    SciTech Connect

    Carpenter, J.M.

    1996-05-01

    This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

  20. Amphibians and Reptiles of Los Alamos County

    SciTech Connect

    Teralene S. Foxx; Timothy K. Haarmann; David C. Keller

    1999-10-01

    Recent studies have shown that amphibians and reptiles are good indicators of environmental health. They live in terrestrial and aquatic environments and are often the first animals to be affected by environmental change. This publication provides baseline information about amphibians and reptiles that are present on the Pajarito Plateau. Ten years of data collection and observations by researchers at Los Alamos National Laboratory, the University of New Mexico, the New Mexico Department of Game and Fish, and hobbyists are represented.

  1. Los Alamos Novel Rocket Design Flight Tested

    ScienceCinema

    Tappan, Bryce

    2015-01-05

    Los Alamos National Laboratory scientists recently flight tested a new rocket design that includes a high-energy fuel and a motor design that also delivers a high degree of safety. Researchers will now work to scale-up the design, as well as explore miniaturization of the system, in order to exploit all potential applications that would require high-energy, high-velocity, and correspondingly high safety margins.

  2. Los Alamos Novel Rocket Design Flight Tested

    SciTech Connect

    Tappan, Bryce

    2014-10-23

    Los Alamos National Laboratory scientists recently flight tested a new rocket design that includes a high-energy fuel and a motor design that also delivers a high degree of safety. Researchers will now work to scale-up the design, as well as explore miniaturization of the system, in order to exploit all potential applications that would require high-energy, high-velocity, and correspondingly high safety margins.

  3. The Los Alamos accelerator code group

    SciTech Connect

    Krawczyk, F.L.; Billen, J.H.; Ryne, R.D.; Takeda, Harunori; Young, L.M.

    1995-05-01

    The Los Alamos Accelerator Code Group (LAACG) is a national resource for members of the accelerator community who use and/or develop software for the design and analysis of particle accelerators, beam transport systems, light sources, storage rings, and components of these systems. Below the authors describe the LAACG`s activities in high performance computing, maintenance and enhancement of POISSON/SUPERFISH and related codes and the dissemination of information on the INTERNET.

  4. Los Alamos synchronous orbit data set

    SciTech Connect

    Baker, D.N.; Higbie, P.R.; Belian, R.D.; Hones, E.W.; Klebesadel, R.W.

    1981-01-01

    Energetic electron (30-15000 keV) and proton 145 keV to 150 MeV) measurements made by Los Alamos National Laboratory sensors at geostationary orbit (6.6 R/sub E/) are summarized. The instrumentation employed and the satellite positions are described. The spacecraft have been variously located, but in their present configuration the Los Alamos satellites designated 1976-059, 1977-007, and 1979-053 are located, respectively, at approx. 70/sup 0/W, approx. 70/sup 0/E, and approx. 135/sup 0/W longitude. Several examples of the high temporal and full three-dimensional spatial measurement capabilities of these instruments are illustrated by examples from the published literature. Discussion is also given for the Los Alamos Synoptic Data Set (SDS) which gives a broad overview of the Los Alamos geostationary orbit measurements. The SDS data are plotted in terms of daily average spectra, 3-hour local time averages, and in a variety of statistical formats. The data summarize conditions from mid-1976 through 1978 (S/C 1976-059) and from early 1977 through 1978 (S/C 1977-007). The SDS compilations presented correspond to measurements at 35/sup 0/W, 70/sup 0/W, and 135/sup 0/W geographic longitude and thus are indicative of conditions at 9/sup 0/, 11/sup 0/, and 4.8/sup 0/ geomagnetic latitude, respectively. The bulk of the SDS report presents data plots which are organized according to Carrington solar rotations and, as such, the data are readily comparable to solar rotation-dependent interplanetary conditions. Potential applications of the Synoptic Data Set (available to all interested users in June 1981) are discussed.

  5. Proceedings of the 1986 workshop on advanced time-of-flight neutron powder diffraction

    SciTech Connect

    Lawson, A.C.; Smith, K.

    1986-09-01

    This report contains abstracts of talks and summaries of discussions from a small workshop held to discuss the future of time-of-flight neutron powder diffraction and its implementation at the Los Alamos Neutron Scattering Center. 47 refs., 3 figs.

  6. Los Alamos National Laboratory Building Cost Index

    SciTech Connect

    Orr, H.D.; Lemon, G.D.

    1983-01-01

    The Los Alamos National Laboratory Building Cost Index indicates that actual escalation since 1970 is near 10% per year. Therefore, the Laboratory will continue using a 10% per year escalation rate for construction estimates through 1985 and a slightly lower rate of 8% per year from 1986 through 1990. The computerized program compares the different elements involved in the cost of a typical construction project, which for our purposes, is a complex of office buildings and experimental laboratores. The input data used in the program consist primarily of labor costs and material and equipment costs. The labor costs are the contractural rates of the crafts workers in the Los Alamos area. For the analysis, 12 field-labor draft categories are used; each is weighted corresponding to the labor craft distribution associated with the typical construction project. The materials costs are current Los Alamos prices. Additional information sources include material and equipment quotes obtained through conversations with vendors and from trade publications. The material and equipment items separate into 17 categories for the analysis and are weighted corresponding to the material and equipment distribution associated with the typical construction project. The building cost index is compared to other national building cost indexes.

  7. Los Alamos National Laboratory building cost index

    SciTech Connect

    Orr, H.D.; Lemon, G.D.

    1982-10-01

    The Los Alamos National Laboratory Building Cost Index indicates that actual escalation since 1970 is near 10% per year. Therefore, the Laboratory will continue using a 10% per year escalation rate for construction estimates through 1985 and a slightly lower rate of 8% per year from 1986 through 1990. The computerized program compares the different elements involved in the cost of a typical construction project, which for our purposes, is a complex of office buildings and experimental laboratories. The input data used in the program consist primarily of labor costs and material and equipment costs. The labor costs are the contractual rates of the crafts workers in the Los Alamos area. For the analysis, 12 field-labor craft categories are used; each is weighted corresponding to the labor craft distribution associated with the typical construction project. The materials costs are current Los Alamos prices. Additional information sources include material and equipment quotes obtained through conversations with vendors and from trade publications. The material and equipment items separate into 17 categories for the analysis and are weighted corresponding to the material and equipment distribution associated with the typical construction project. The building cost index is compared to other national building cost indexes.

  8. Exploration geochemistry: The Los Alamos experience

    SciTech Connect

    Maassen, L.W.; Bolivar, S.L.

    1989-01-01

    Los Alamos National Laboratory became actively involved in geochemical exploration in 1975 by conducting a reconnaissance-scale exploration program for uranium as part of the National Uranium Resource Evaluation program. Initially, only uranium and thorium were analyzed. By 1979 Los Alamos was analyzing a multielement suite. The data were presented in histograms and as black and white concentration plots for uranium and thorium only. Data for the remaining elements were presented as hard copy data listings in an appendix to the report. In 1983 Los Alamos began using exploration geochemistry for the purpose of finding economic mineral deposits to help stimulate the economies of underdeveloped countries. Stream-sediment samples were collected on the Caribbean island of St. Lucia and a geochemical atlas of that island was produced. The data were statistically smoothed and presented as computer-generated color plots of each element of the multielement suite. Studies for the US Bureau of Land Management in 1984 consisted of development of techniques for the integration of several large data sets, which could then be used for computer-assisted mineral resource assessments. A supervised classification technique was developed which compares the attributes of grid cells containing mines or mineral occurrences with attributes of unclassified cells not known to contain mines or occurrences. Color maps indicate how closely unclassified cells match in attributes the cells with mines or occurrences. 20 refs., 1 fig., 1 tab.

  9. Determination of spallation neutron flux through spectral adjustment techniques

    NASA Astrophysics Data System (ADS)

    Mosby, M. A.; Engle, J. W.; Jackman, K. R.; Nortier, F. M.; Birnbaum, E. R.

    2016-08-01

    The Los Alamos Isotope Production Facility (IPF) creates medical isotopes using a proton beam impinged on a target stack. Spallation neutrons are created in the interaction of the beam with target. The use of these spallation neutrons to produce additional radionuclides has been proposed. However, the energy distribution and magnitude of the flux is not well understood. A modified SAND-II spectral adjustment routine has been used with radioactivation foils to determine the differential neutron fluence for these spallation neutrons during a standard IPF production run.

  10. Monte Carlo code for neutron scattering instrumentation design and analysis

    SciTech Connect

    Daemen, L.; Fitzsimmons, M.; Hjelm, R.; Olah, G.; Roberts, J.; Seeger, P.; Smith, G.; Thelliez, T.

    1996-09-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) at the Los Alamos National Laboratory (LANL). The development of next generation, accelerator based neutron sources calls for the design of new instruments for neutron scattering studies of materials. It will be necessary, in the near future, to evaluate accurately and rapidly the performance of new and traditional neutron instruments at short- and long-pulse spallation neutron sources, as well as continuous sources. We have developed a code that is a design tool to assist the instrument designer model new or existing instruments, test their performance, and optimize their most important features.

  11. Neutron Imaging Developments at LANSCE

    NASA Astrophysics Data System (ADS)

    Nelson, Ron; Hunter, James; Schirato, Richard; Vogel, Sven; Swift, Alicia; Ickes, Tim; Ward, Bill; Losko, Adrian; Tremsin, Anton

    2015-10-01

    Neutron imaging is complementary to x-ray imaging because of its sensitivity to light elements and greater penetration of high-Z materials. Energy-resolved neutron imaging can provide contrast enhancements for elements and isotopes due to the variations with energy in scattering cross sections due to nuclear resonances. These cross section differences exist due to compound nuclear resonances that are characteristic of each element and isotope, as well as broader resonances at higher energies. In addition, multi-probe imaging, such as combined photon and neutron imaging, is a powerful tool for discerning properties and features in materials that cannot be observed with a single probe. Recently, we have demonstrated neutron imaging, both radiography and computed tomography, using the moderated (Lujan Center) and high-energy (WNR facility) neutron sources at LANSCE. Flat panel x-ray detectors with suitable scintillator-converter screens provide good sensitivity for both low and high neutron energies. Micro-Channel-Plate detectors and iCCD scintillator camera systems that provide the fast time gating needed for energy-resolved imaging have been demonstrated as well. Examples of recent work will be shown including fluid flow in plants and imaging through dense thick objects. This work is funded by the US Department of Energy, National Nuclear Security Administration, and performed by Los Alamos National Security LLC under Contract DE-AC52-06NA25396.

  12. PROCESS MODELING AND ANALYSIS FOR RECOVERY OF PUBE SOURCES AT LOS ALAMOS

    SciTech Connect

    D. KORNREICH; ET AL

    2000-11-01

    Los Alamos National Laboratory maintains one of the premier plutonium processing facilities in the country. The plutonium facility supports several defense- and nondefense-related missions. This paper describes process-modeling efforts focused on the operations related to the Radioactive Source Recovery Program, which recovers the plutonium from plutonium-beryllium neutron sources. This program accomplishes at least two goals: it is evidence of good stewardship of a national resource, plutonium, and destroys a potential health hazard, the neutron source, by separating the plutonium from the beryllium in sources that are no longer being used in various industries or the military. We examine the processes related to source recovery operations in terms of throughput, ionizing radiation exposure to workers, and mass balances using two discrete-event simulation tools: Extend{trademark}, which is commercially available; and ProMoS, which is in-house software specifically tailored for modeling nuclear-materials operations.

  13. A high power accelerator driver system for spallation neutron sources

    SciTech Connect

    Jason, A.; Blind, B.; Channell, P.

    1996-07-01

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). For several years, the Los Alamos Meson Physics Facility (LAMPF) and the Proton Storage Ring (PSR) have provided a successful driver for the nearly 100-kW Los Alamos Neutron Scattering Center (LANSCE) source. The authors have studied an upgrade to this system. The goal of this effort was to establish a credible design for the accelerator driver of a next-generation source providing 1-MW of beam power. They have explored a limited subset of the possible approaches to a driver and have considered only the low 1-MW beam power. The next-generation source must utilize the optimum technology and may require larger neutron intensities than they now envision.

  14. Oedometric Small Angle Neutron Scattering: In-Situ Observation of Deformation Partitioning in Clay-rich Samples

    NASA Astrophysics Data System (ADS)

    Bryan, C. R.; Heath, J. E.; Hjelm, R.; Taylor, M.; Olds, D.; Dewers, T. A.

    2014-12-01

    We present novel oedometric small angle neutron scattering (SANS) on deforming clay-rich materials. Oedometric SANS involves a non-hydrostatic pressure vessel (i.e., the oedometer) that places a porous sample under uniaxial strain with control of applied pore pressure. The oedometer is optimized for neutron optics of SANS on the Low-Q Diffractometer of the Los Alamos Neutron Science Center. The device enables normal oedometric measurements of time-dependent compaction, but with SANS for in situ observation of pore structure evolution under uniaxial strain as a function of effective stress and pore fluid compositions. We present preliminary examination of clay compaction and testing of the device. Funding from the DOE Basic Energy Sciences Geosciences Program is gratefully acknowledged. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. DETERMINISTIC TRANSPORT METHODS AND CODES AT LOS ALAMOS

    SciTech Connect

    J. E. MOREL

    1999-06-01

    The purposes of this paper are to: Present a brief history of deterministic transport methods development at Los Alamos National Laboratory from the 1950's to the present; Discuss the current status and capabilities of deterministic transport codes at Los Alamos; and Discuss future transport needs and possible future research directions. Our discussion of methods research necessarily includes only a small fraction of the total research actually done. The works that have been included represent a very subjective choice on the part of the author that was strongly influenced by his personal knowledge and experience. The remainder of this paper is organized in four sections: the first relates to deterministic methods research performed at Los Alamos, the second relates to production codes developed at Los Alamos, the third relates to the current status of transport codes at Los Alamos, and the fourth relates to future research directions at Los Alamos.

  16. Energy supply and environmental issues: The Los Alamos National Laboratory experience in regional and international programs

    SciTech Connect

    Goff, S.J.

    1995-12-31

    The Los Alamos National Laboratory, operated by the University of California, encompasses more than forty-three square miles of mesas and canyons in northern New Mexico. A Department of Energy national laboratory, Los Alamos is one of the largest multidisciplinary, multiprogram laboratories in the world. Our mission, to apply science and engineering capabilities to problems of national security, has expanded to include a broad array of programs. We conduct extensive research in energy, nuclear safeguards and security, biomedical science, computational science, environmental protection and cleanup, materials science, and other basic sciences. The Energy Technology Programs Office is responsible for overseeing and developing programs in three strategic areas: energy systems and the environment, transportation and infrastructure, and integrated chemicals and materials processing. Our programs focus on developing reliable, economic and environmentally sound technologies that can help ensure an adequate supply of energy for the nation. To meet these needs, we are involved in programs that range from new and enhanced oil recovery technologies and tapping renewable energy sources, through efforts in industrial processes, electric power systems, clean coal technologies, civilian radioactive waste, high temperature superconductivity, to studying the environmental effects of energy use.

  17. Spin and parity assignments for {sup 94,95}Mo neutron resonances

    SciTech Connect

    Sheets, S. A.; Agvaanluvsan, U.; Becker, J. A.; Parker, W. E.; Wu, C. Y.; Becvar, F.; Krticka, M.; Bredeweg, T. A.; Haight, R. C.; Jandel, M.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Wilhelmy, J. B.; Mitchell, G. E.; Sharapov, E. I.; Tomandl, I.

    2007-12-15

    The {gamma} rays following the {sup 94,95}Mo(n,{gamma}) reactions were measured as a function of incident neutron energy by the time-of-flight method with the DANCE (Detector for Advanced Neutron Capture Experiments) array of 160 BaF{sub 2} scintillation detectors at the Los Alamos Neutron Science Center. The targets were enriched samples: 91.59% {sup 94}Mo and 96.47% {sup 95}Mo. The {gamma}-ray multiplicities and energy spectra for different multiplicities were measured in s- and p-wave resonances up to E{sub n}=10 keV for {sup 94}Mo and up to E{sub n}=2 keV for {sup 95}Mo. Definite spins and parities were assigned in {sup 96}Mo for about 60% of the resonances, and tentative spins and parities were assigned for the remaining resonances. In {sup 95}Mo the parities were determined for the observed resonances, confirming previously known assignments.

  18. The performance of neutron scattering spectrometers at a long-pulse spallation source

    SciTech Connect

    Pynn, R.

    1995-04-01

    The first conclusion the author wants to draw is that comparison of the performance of neutron scattering spectrometers at CW and pulsed sources is simpler for long-pulsed sources than it is for the short-pulse variety. Even though detailed instrument design and assessment will require Monte Carlo simulations (which have already been performed at Los Alamos for SANS and reflectometry), simple arguments are sufficient to assess the approximate performance of spectrometers at an LPSS and to support the contention that a 1 MW long-pulse source can provide attractive performance, especially for instrumentation designed for soft-condensed-matter science. Because coupled moderators can be exploited at such a source, its time average cold flux is equivalent to that of a research reactor with a power of about 15 MW, so only a factor of 4 gain from source pulsing is necessary to obtain performance that is comparable with the ILL. In favorable cases, the gain from pulsing can be even more than this, approaching the limit set by the peak flux, giving about 4 times the performance of the ILL. Because of its low duty factor, an LPSS provides the greatest performance gains for relatively low resolution experiments with cold neutrons. It should thus be considered complementary to short pulse sources which are most effective for high resolution experiments using thermal or epithermal neutrons.

  19. Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

    SciTech Connect

    Malenfant, R.E.

    1993-10-01

    Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation.

  20. Coated Fiber Neutron Detector Test

    SciTech Connect

    Lintereur, Azaree T.; Ely, James H.; Kouzes, Richard T.; Stromswold, David C.

    2009-10-23

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Reported here are the results of tests of the 6Li/ZnS(Ag)-coated non-scintillating plastic fibers option. This testing measured the required performance for neutron detection efficiency and gamma ray rejection capabilities of a system manufactured by Innovative American Technology (IAT).

  1. Neutron Particle Effects on a Quad-Redundant Flight Control Computer

    NASA Technical Reports Server (NTRS)

    Eure, Kenneth; Belcastro, Celeste M.; Gray, W Steven; Gonzalex, Oscar

    2003-01-01

    This paper describes a single-event upset experiment performed at the Los Alamos National Laboratory. A closed-loop control system consisting of a Quad-Redundant Flight Control Computer (FCC) and a B737 simulator was operated while the FCC was exposed to a neutron beam. The purpose of this test was to analyze the effects of neutron bombardment on avionics control systems operating at altitudes where neutron strikes are probable. The neutron energy spectrum produced at the Los Alamos National Laboratory is similar in shape to the spectrum of atmospheric neutrons but much more intense. The higher intensity results in accelerated life tests that are representative of the actual neutron radiation that a FCC may receive over a period of years.

  2. Los Alamos Before and After the Fire

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 4, 2000, a prescribed fire was set at Bandelier National Monument, New Mexico, to clear brush and dead and dying undergrowth to prevent a larger, subsequent wildfire. Unfortunately, due to high winds and extremely dry conditions in the surrounding area, the prescribed fire quickly raged out of control and, by May 10, the blaze had spread into the nearby town of Los Alamos. In all, more than 20,000 people were evacuated from their homes and more than 200 houses were destroyed as the flames consumed about 48,000 acres in and around the Los Alamos area. The pair of images above were acquired by the Enhanced Thematic Mapper Plus (ETM+) sensor, flying aboard NASA's Landsat 7 satellite, shortly before the Los Alamos fire (top image, acquired April 14) and shortly after the fire was extinguished (lower image, June 17). The images reveal the extent of the damage caused by the fire. Combining ETM+ channels 7, 4, and 2 (one visible and two infrared channels) results in a false-color image where vegetation appears as bright to dark green. Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. In the lower image, the areas recently burned appear bright red. Landsat 7 data courtesy United States Geological Survey EROS DataCenter. Images by Robert Simmon, NASA GSFC.

  3. LAMPF II workshop, Los Alamos National Laboratory, Los Alamos, New Mexico, February 1-4, 1982

    SciTech Connect

    Thiessen, H.A.

    1982-01-01

    This report contains the proceedings of the first LAMPF II Workshop held at Los Alamos February 1 to 4, 1982. Included are the talks that were available in written form. The conclusion of the participants was that there are many exciting areas of physics that will be addressed by such a machine.

  4. Biological assessment for the effluent reduction program, Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    Cross, S.P.

    1996-08-01

    This report describes the biological assessment for the effluent recution program proposed to occur within the boundaries of Los Alamos National Laboratory. Potential effects on wetland plants and on threatened and endangered species are discussed, along with a detailed description of the individual outfalls resulting from the effluent reduction program.

  5. Los Alamos National Laboratory computer benchmarking 1982

    SciTech Connect

    Martin, J.L.

    1983-06-01

    Evaluating the performance of computing machinery is a continual effort of the Computer Research and Applications Group of the Los Alamos National Laboratory. This report summarizes the results of the group's benchmarking activities performed between October 1981 and September 1982, presenting compilation and execution times as well as megaflop rates for a set of benchmark codes. Tests were performed on the following computers: Cray Research, Inc. (CRI) Cray-1S; Control Data Corporation (CDC) 7600, 6600, Cyber 73, Cyber 825, Cyber 835, Cyber 855, and Cyber 205; Digital Equipment Corporation (DEC) VAX 11/780 and VAX 11/782; and Apollo Computer, Inc., Apollo.

  6. Ultraprecision machining of optics at Los Alamos

    SciTech Connect

    Rhorer, R.L.; Gauler, A.L.; Colston, E.W.; Ruhe, J.R.

    1982-01-01

    Ultraprecision machine tools are used at the Los Alamos National Laboratory for single-point diamond turning of optics and other precision parts. Measurements of a 50-mm-diam copper flat illustrate the quality of a part that can be machined on the Moore No. 3 lathe. Measurements of a 0.4-m-diam aluminum mirror with a 20-m radius of curvature are presented as an example of a part machined on the Moore No. 5 lathe. A varying frequency sine wave grating shows a type of special optical grating that can be produced using the Pneumo lathe.

  7. Ultraprecision machining of optics at Los Alamos

    SciTech Connect

    Rhorer, R.L.; Gauler, A.L.; Colston, E.W.; Ruhe, J.R.

    1981-01-01

    Ultraprecision machine tools are used at Los Alamos for single point diamond turning of optics and other precision parts. Measurements of a 50-mm-dia copper flat are used to illustrate the quality of a part which can be machined on the Moore No. 3 lathe. Measurements of a 0.4-m-dia aluminum mirror with a 20-m radius-of-curvature are presented as an example of a part machined on the Moore No. 5 lathe. A varying frequency sine wave grating is used to show a type of special optical grating which can be produced using the Pneumo lathe.

  8. Environmental Programs at Los Alamos National Laboratory

    SciTech Connect

    Jones, Patricia

    2012-07-11

    Summary of this project is: (1) Teamwork, partnering to meet goals - (a) Building on cleanup successes, (b) Solving legacy waste problems, (c) Protecting the area's environment; (2) Strong performance over the past three years - (a) Credibility from four successful Recovery Act Projects, (b) Met all Consent Order milestones, (c) Successful ramp-up of TRU program; (3) Partnership between the National Nuclear Security Administration's Los Alamos Site Office, DOE Carlsbad Field Office, New Mexico Environment Department, and contractor staff enables unprecedented cleanup progress; (4) Continued focus on protecting water resources; and (5) All consent order commitments delivered on time or ahead of schedule.

  9. Prompt Fission Neutron Spectra of Actinides

    SciTech Connect

    Capote, R; Chen, Y J; Hambsch, F J; Kornilov, N V; Lestone, J P; Litaize, O; Morillon, B; Neudecker, D; Oberstedt, S; Ohsawa, T; Smith, D. L.

    2016-01-01

    The energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) “Evaluation of Prompt Fission Neutron Spectra of Actinides”was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei. The following technical areas were addressed: (i) experiments and uncertainty quantification (UQ): New data for neutron-induced fission of 233U, 235U, 238U, and 239Pu have been measured, and older data have been compiled and reassessed. There is evidence from the experimental work of this CRP that a very small percentage of neutrons emitted in fission are actually scission neutrons; (ii) modeling: The Los Alamos model (LAM) continues to be the workhorse for PFNS evaluations. Monte Carlo models have been developed that describe the fission phenomena microscopically, but further development is needed to produce PFNS evaluations meeting the uncertainty targets; (iii) evaluation methodologies: PFNS evaluations rely on the use of the least-squares techniques for merging experimental and model data. Considerable insight was achieved on how to deal with the problem of too small uncertainties in PFNS evaluations. The importance of considering that all experimental PFNS data are “shape” data was stressed; (iv) PFNS evaluations: New evaluations, including covariance data, were generated for major actinides including 1) non-model GMA evaluations of the 235U(nth,f), 239Pu(nth,f), and 233U(nth,f) PFNS based exclusively on experimental data (0.02 ≤ E ≤ 10 MeV), which resulted in PFNS average energies E of 2.00±0.01, 2.073±0.010, and 2.030±0.013 MeV, respectively; 2) LAM evaluations of neutron-induced fission spectra on uranium and plutonium targets with improved UQ for incident energies from thermal up to 30 MeV; and 3) Point-by-Point calculations for 232Th, 234U and 237Np targets; and (v) data

  10. First record of single event upset on the ground, Cray-1 computer memory at Los Alamos in 1976

    SciTech Connect

    Michalak, Sarah E; Quinn, Heather M; Grider, Gary A; Iwanchuk, Paul N; Morrison, John F; Wender, Stephen A; Normand, Eugene; Wert, Jerry L; Johnson, Steve

    2010-01-01

    Records of bit flips in the Cray-1 computer installed at Los Alamos in 1976 lead to an upset rate in the Cray-1 's bipolar SRAMs that correlates with the SEUs being induced by the atmospheric neutrons. In 1976 the Cray Research Company delivered its first supercomputer, the Cray-1, installing it at Los Alamos National Laboratory. Los Alamos had competed with the Lawrence Livermore National Laboratory for the Cray-1 and won, reaching an agreement with Seymour Cray to install the machine for a period of six months for free, after which they could decide whether to buy, lease or return it. As a result, Los Alamos personnel kept track of the computer reliability and performance and so we know that during those six months of operation, 152 memory parity errors were recorded. The computer memory consisted of approximately 70,000 1Kx1 bipolar ECL static RAMs, the Fairchild 10415. What the Los Alamos engineers didn't know is that those bit flips were the result of single event upsets (SEUs) caused by the atmospheric neutrons. Thus, these 152 bit flips were the first recorded SEUs on the earth, and were observed 2 years before the SEUs in the Intel DRAMs that had been found by May and Woods in 1978. The upsets in the DRAMs were shown to have been caused by alpha particles from the chip packaging material. In this paper we will demonstrate that the Cray-1 bit flips, which were found through the use of parity bits in the Cray-1, were likely due to atmospheric neutrons. This paper will follow the same approach as that of the very first paper to demonstrate single event effects, which occurred in satellite flip-flop circuits in 1975. The main difference is that in the four events that occurred over the course of 17 satellite years of operation were shown to be due to single event effects just a few years after those satellite anomalies were recorded. In the case of the Cray-1 bit flips, there has been a delay of more than 30 years between the occurrence of the bit flips and the

  11. Basic physics with spallation-neutron sources

    SciTech Connect

    Michaudon, A.F.

    1994-05-01

    The neutron has unique intrinsic properties widely used in basic and applied sciences. The neutron plays a well-known role in applied sciences and technology and is a unique probe well suited for the exploration of condensed-matter properties. But the neutron is also used for many other basic-physics studies, including nuclear physics, particle physics, fundamental physics, astrophysics, and cosmology. These last studies are briefly reviewed in this paper. Spallation-neutron sources today have unmatched neutron-beam properties for such studies and have great potential in future technological developments whereby these studies could be carried out under much improved conditions.

  12. Spallation Neutron Source reaches megawatt power

    ScienceCinema

    Dr. William F. Brinkman

    2010-01-08

    The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

  13. Spallation Neutron Source reaches megawatt power

    SciTech Connect

    Dr. William F. Brinkman

    2009-09-30

    The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

  14. Audit of personal property management at Los Alamos National Laboratory

    SciTech Connect

    Not Available

    1993-12-07

    The Department of Energy`s (Department) Albuquerque Operations Office (Albuquerque) and the Los Alamos National Laboratory (Los Alamos) are responsible for ensuring that Los Alamos maintains an efficient and effective personal property management system that protects, identifies, and controls Government-owned personal property in accordance with applicable regulations. Albuquerque is responsible for reviewing and approving Los Alamos` personal property management system. Los Alamos is responsible for ensuring that personal property is properly protected, identified, and controlled. The audit disclosed that Los Alamos did not have an efficient and effective personal property management system to ensure that personal property was adequately protected, identified, and controlled. In addition, Albuquerque did not approve or disapprove Los Alamos` personal property management system consistent with Federal and Department regulations. Specifically, the audit showed that Los Alamos did not account for $11.6 million of personal property. In addition, $22.2 million of personal property was not properly recorded in the database, $61.7 million of personal property could not be inventoried, and loans to employees and other entities were not adequately justified. As a result, from a total personal property inventory of approximately $1 billion, it is estimated that $100 million of personal property may not be accounted for, and $207 million may not be correctly recorded in the database. Moreover, substantial amounts of personal property on loan to employees and other entities were at risk of unauthorized use. Albuquerque concurred with the finding and agreed to implement the corrective actions recommended in the report.

  15. The Climate at Los Alamos; Are we measurement changes?

    SciTech Connect

    Dewart, Jean Marie

    2015-04-16

    A new report shows new graphic displays of the weather trends in Los Alamos, New Mexico, and at the Los Alamos National Laboratory (LANL). The graphs show trends of average, minimum average, and maximum average temperature for summer and winter months going back decades. Records of summer and winter precipitation are also included in the report.

  16. Neutron Star Interior Composition Explorer (NICE)

    NASA Technical Reports Server (NTRS)

    Gendreau, Keith C.; Arzoumanian, Zaven

    2008-01-01

    This viewgraph presentation contains an overview of the mission of the Neutron Star Interior Composition Explorer (NICE), a proposed International Space Station (ISS) payload dedicated ot the study of neutron stars. There are also reviews of the Science Objectives of the payload,the science measurements, the design and the expected performance for the instruments for NICE,

  17. Comparison of graphite, aluminum, and TransHab shielding material characteristics in a high-energy neutron field.

    PubMed

    Badhwar, G D; Huff, H; Wilkins, R; Thibeault, Sheila

    2002-12-01

    Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal energy spectra with graphite, aluminum, and a TransHab build-up as shielding, was carried out at the Los Alamos Nuclear Science Center neutron facility. It is a continuation of a previous study using regolith and doped polyethylene materials. This paper describes the results and their comparison with the previous study. PMID:12455499

  18. Upgrade and Certification of the Los Alamos National Laboratory SHENC 2011 - 12270

    SciTech Connect

    Stanfield, S.B.; Villani, M.; Barton, P.T.; Gerlock, C.; Nakazawa, D.; Baumann, R.C.; Mowry, R.; Harvill, J.P.

    2012-07-01

    Nondestructive assay measurements of Transuranic (TRU) waste at Los Alamos National Laboratory (LANL) required the addition of a standard waste box (SWB) assay system. A Super High Efficiency Neutron Counter (SHENC) located at Hanford was identified to be relocated to LANL. After careful evaluation of waste streams at LANL, it was determined that the current configuration of the SHENC was not sufficient to quantify certain waste streams. At LANL, there is still a large amount of waste that needs to be retrieved and repackaged within SWB's to meet agreements with the State of New Mexico. Prior to relocating the SHENC, the only assay systems available were High Efficiency Neutron Counters having only a 55-gallon drum capacity. Further analyses indicated that the SHENC system should be capable of quantitative gamma measurements that are to be linked, and combined, with the neutron measurements. The SHENC system was therefore augmented with a new high-resolution gamma spectroscopy system using BE5030 detectors and upgraded gamma electronics. The neutron side of the system was also upgraded with an advanced shift register (JSR-15), an improved Programmable Logic Controller and NDA-2000 software. This report will include calibration of both the neutron and gamma modalities of the SHENC system and how the modality results are combined to produce a single assay result. Preliminary performance results will be discussed based on both mock and real waste measurements. Discussions will also include a complete description of the adjustable parameters as well as the calibration plan, techniques and validations including calibration confirmation based on the Waste Isolation Pilot Plant Waste Acceptance Criteria (WIPP-WAC). The SHENC was successfully upgraded to efficiently measure the complex waste streams at Los Alamos National Laboratory. A new PLC was successfully added to the system for Add-A-Source control. A new shift register was added to the SHENC (JSR-15) which provides

  19. Isotopic Composition of Natural Nitrate in Groundwater in Los Alamos, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Chrystal, A. E.; Heikoop, J. M.; Longmire, P.; Dale, M.; Larson, T. E.; Perkins, G.; Fabyrka-Martin, J.; Simmons, A. M.; Fessenden-Rahn, J.

    2009-12-01

    Los Alamos National Laboratory (LANL) has established background concentrations for various dissolved constituents in local groundwater from perched-intermediate and regional aquifers in the vicinity of Los Alamos in north-central New Mexico. Typical background concentrations of nitrate (NO3-) are on the order of 0.31 mg/L as N (0.02 mM/L). In addition to natural sources, anthropogenic sources of NO3- in local groundwaters include industrial and treated sewage discharges released from LANL facilities, and treated sewage effluent discharges from Los Alamos County. We are using stable isotopes of nitrogen and oxygen in NO3- to distinguish among these sources, define groundwater flow paths, and evaluate groundwater mixing. Following the approach of McMahon and Böhlke (2006), we have explored the δ18O[NO3-] of water samples taken from background wells and springs in the Los Alamos area. NO3- from a spring and a well located in the Valles caldera, upgradient and upwind (relative to prevailing winds) of Los Alamos has δ15N and δ18O values of approximately 4.8 ‰ and -2.6 ‰, respectively. Tritium and unadjusted radiocarbon analyses indicate that these caldera waters predate LANL operations commencing in 1943. NO3- from groundwater locations in Los Alamos that exhibit background conditions has isotopic values similar to those of the caldera groundwater. Because local groundwater is relatively oxidizing, denitrification is not expected to be a factor in altering isotopic compositions of NO3-. Results indicate that there is little direct atmospheric contribution to dissolved NO3-, and that most NO3- is derived from bacterial nitrification in which one oxygen atom comes from atmospheric oxygen and two oxygen atoms come from soil porewater. Oxygen isotope values plot slightly below the expected isotopic trend for a 1:2 mix of these two sources, indicating either slight fractionation of oxygen isotopes during nitrification, or potential mixing with geological sources of

  20. Neutron Capture Reactions on lu Isotopes at Dance

    NASA Astrophysics Data System (ADS)

    Roig, O.; Meot, V.; Daugas, J.-M.; Morel, P.; Jandel, M.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Wouters, J. M.

    2013-03-01

    The DANCE1 (Detector for Advanced Neutron Capture Experiments) array at LANSCE spallation neutron source in Los Alamos has been used to obtain the neutron radiative capture cross sections for 175Lu and 176Lu with neutron energies from thermal up to 100 keV. Both isotopes are of current interest for the nucleosynthesis s-process.2,3 Three targets were used to perform these measurements. One was natural Lu foil of 31 mg/cm2 and the other two were isotope-enriched targets of 175Lu and 176Lu. Firstly, the cross sections were obtained by normalizing yield to a well-known cross section at the thermal neutron energy. Now, we want to obtain absolute cross sections of radiative capture through a precise neutron flux determination, an accurate target mass measurement and an efficiency determination of the DANCE array.

  1. Portable MRI developed at Los Alamos

    SciTech Connect

    Espy, Michelle

    2015-04-22

    Scientists at Los Alamos National Laboratory are developing an ultra-low-field Magnetic Resonance Imaging (MRI) system that could be low-power and lightweight enough for forward deployment on the battlefield and to field hospitals in the World's poorest regions. "MRI technology is a powerful medical diagnostic tool," said Michelle Espy, the Battlefield MRI (bMRI) project leader, "ideally suited for imaging soft-tissue injury, particularly to the brain." But hospital-based MRI devices are big and expensive, and require considerable infrastructure, such as large quantities of cryogens like liquid nitrogen and helium, and they typically use a large amount of energy. "Standard MRI machines just can't go everywhere," said Espy. "Soldiers wounded in battle usually have to be flown to a large hospital and people in emerging nations just don't have access to MRI at all. We've been in contact with doctors who routinely work in the Third World and report that MRI would be extremely valuable in treating pediatric encephalopathy, and other serious diseases in children." So the Los Alamos team started thinking about a way to make an MRI device that could be relatively easy to transport, set up, and use in an unconventional setting. Conventional MRI machines use very large magnetic fields that align the protons in water molecules to then create magnetic resonance signals, which are detected by the machine and turned into images. The large magnetic fields create exceptionally detailed images, but they are difficult and expensive to make. Espy and her team wanted to see if images of sufficient quality could be made with ultra-low-magnetic fields, similar in strength to the Earth's magnetic field. To achieve images at such low fields they use exquisitely sensitive detectors called Superconducting Quantum Interference Devices, or SQUIDs. SQUIDs are among the most sensitive magnetic field detectors available, so interference with the signal is the primary stumbling block. "SQUIDs are

  2. The neutron channeling phenomenon.

    PubMed

    Khanouchi, A; Sabir, A; Boulkheir, M; Ichaoui, R; Ghassoun, J; Jehouani, A

    1997-01-01

    Shields, used for protection against radiation, are often pierced with vacuum channels for passing cables and other instruments for measurements. The neutron transmission through these shields is an unavoidable phenomenon. In this work we study and discuss the effect of channels on neutron transmission through shields. We consider an infinite homogeneous slab, with a fixed thickness (20 lambda, with lambda the mean free path of the neutron in the slab), which contains a vacuum channel. This slab is irradiated with an infinite source of neutrons on the left side and on the other side (right side) many detectors with windows equal to 2 lambda are placed in order to evaluate the neutron transmission probabilities (Khanouchi, A., Aboubekr, A., Ghassoun, J. and Jehouani, A. (1994) Rencontre Nationale des Jeunes Chercheurs en Physique. Casa Blanca Maroc; Khanouchi, A., Sabir, A., Ghassoun, J. and Jehouani, A. (1995) Premier Congré International des Intéractions Rayonnements Matière. Eljadida Maroc). The neutron history within the slab is simulated by the Monte Carlo method (Booth, T. E. and Hendricks, J. S. (1994) Nuclear Technology 5) and using the exponential biasing technique in order to improve the Monte Carlo calculation (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Aboubker, A. (1994) In Proceedings of the 6th International Symposium on Radiation Physics, Rabat, Morocco). Then different geometries of the vacuum channel have been studied. For each geometry we have determined the detector response and calculated the neutron transmission probability for different detector positions. This neutron transmission probability presents a peak for the detectors placed in front of the vacuum channel. This study allowed us to clearly identify the neutron channeling phenomenon. One application of our study is to detect vacuum defects in materials. PMID:9463884

  3. Chemical decontamination technical resources at Los Alamos National Laboratory (2008)

    SciTech Connect

    Moore, Murray E

    2008-01-01

    This document supplies information resources for a person seeking to create planning or pre-planning documents for chemical decontamination operations. A building decontamination plan can be separated into four different sections: Pre-planning, Characterization, Decontamination (Initial response and also complete cleanup), and Clearance. Of the identified Los Alamos resources, they can be matched with these four sections: Pre-planning -- Dave Seidel, EO-EPP, Emergency Planning and Preparedness; David DeCroix and Bruce Letellier, D-3, Computational fluids modeling of structures; Murray E. Moore, RP-2, Aerosol sampling and ventilation engineering. Characterization (this can include development projects) -- Beth Perry, IAT-3, Nuclear Counterterrorism Response (SNIPER database); Fernando Garzon, MPA-11, Sensors and Electrochemical Devices (development); George Havrilla, C-CDE, Chemical Diagnostics and Engineering; Kristen McCabe, B-7, Biosecurity and Public Health. Decontamination -- Adam Stively, EO-ER, Emergency Response; Dina Matz, IHS-IP, Industrial hygiene; Don Hickmott, EES-6, Chemical cleanup. Clearance (validation) -- Larry Ticknor, CCS-6, Statistical Sciences.

  4. Los Alamos Shows Airport Security Technology at Work

    ScienceCinema

    Espy, Michelle; Schultz, Larry; Hunter, James

    2014-06-24

    Los Alamos scientists have advanced a Magnetic Resonance Imaging (MRI) technology that may provide a breakthrough for screening liquids at airport security. They've added low-power X-ray data to the mix, and as a result have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new system is named MagRay. The goal is to quickly and accurately distinguish between liquids that visually appear identical. For example, what appears to be a bottle of white wine could potentially be nitromethane, a liquid that could be used to make an explosive. Both are clear liquids, one would be perfectly safe on a commercial aircraft, the other would be strictly prohibited. How to tell them apart quickly without error at an airport security area is the focus of Michelle Espy, Larry Schultz and their team. In this video, Espy and the MagRay team explain how the new technology works, how they've developed an easy operator interface, and what the next steps might be in transitioning this technology to the private sector.

  5. Los Alamos Shows Airport Security Technology at Work

    SciTech Connect

    Espy, Michelle; Schultz, Larry; Hunter, James

    2013-11-25

    Los Alamos scientists have advanced a Magnetic Resonance Imaging (MRI) technology that may provide a breakthrough for screening liquids at airport security. They've added low-power X-ray data to the mix, and as a result have unlocked a new detection technology. Funded in part by the Department of Homeland Security's Science and Technology Directorate, the new system is named MagRay. The goal is to quickly and accurately distinguish between liquids that visually appear identical. For example, what appears to be a bottle of white wine could potentially be nitromethane, a liquid that could be used to make an explosive. Both are clear liquids, one would be perfectly safe on a commercial aircraft, the other would be strictly prohibited. How to tell them apart quickly without error at an airport security area is the focus of Michelle Espy, Larry Schultz and their team. In this video, Espy and the MagRay team explain how the new technology works, how they've developed an easy operator interface, and what the next steps might be in transitioning this technology to the private sector.

  6. M-BAND Analysis of Chromosome Aberration In Human Epithelial Cells exposed to Gamma-ray and Secondary Neutrons of Low Dose Rate

    NASA Technical Reports Server (NTRS)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's "30L" beam line is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams at an entrance dose rate of 2.5 cGy/hr or gamma-ray at 1.7cGy/hr, and assessed the induction of chromosome aberrations that were identified with mBAND. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results for gamma-rays and 600 MeV/nucleon Fe ions of high dose rate, the neutron data showed a higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. The low dose rate gamma-rays induced a lower frequency of chromosome aberrations than high dose rate gamma-rays, but the inversion spectrum was similar for the same cytotoxic effect. The distribution of damage sites on chromosome 3 for different radiation types will also be discussed.

  7. In-situ Time-Resolved Neutron Diffraction Measurements of Microstructure Variations during Friction Stir Welding in a 6061-T6 Aluminum Alloy

    SciTech Connect

    Woo, Wan Chuck; Wang, Xun-Li; Ungar, Prof Tomas; Feng, Zhili; David, Stan A; Clausen, B; Hubbard, Camden R

    2008-01-01

    The microstructure change is one of the most important research areas in the friction stir welding (FSW). However, direct observation of microstructure changes during FSW has been extremely challenging because many measurement techniques are inapplicable. Recently developed in-situ time-resolved neutron diffraction methodology, which drastically improves the temporal resolution of neutron diffraction, enables to observe the transient microstructure changes during FSW. We installed a portable FSW system in the Spectrometer for MAterials Research at Temperature and Stress (SMARTS) at Los Alamos Neutron Science Center and the FSW was made on 6.35mm-thickness 6061-T6 Al alloy plate. At the same time, the neutron beam was centered on the mid-plane of the Al plate at 8 mm from the tool center (underneath the tool shoulder) and the diffraction peak was continuously measured during welding. The peak broadening analysis has been performed using the Williamson-Hall Method. The result shows that the dislocation density of about 3.2 x 10^15 m-2 duing FSW, which is the significant increse compared to the before (4.5 x 10^14 m-2) and after (4.0 x 10^14 m-2) the FSW. The quantitatively analysis of the grain structure can provide an insight to understand the transient variation of the microstructure during FSW.

  8. Preliminary time-of-flight neutron diffraction studies of Escherichia coli ABC transport receptor phosphate-binding protein at the Protein Crystallography Station

    PubMed Central

    Sippel, K. H.; Bacik, J.; Quiocho, F. A.; Fisher, S. Z.

    2014-01-01

    Inorganic phosphate is an essential molecule for all known life. Organisms have developed many mechanisms to ensure an adequate supply, even in low-phosphate conditions. In prokaryotes phosphate transport is instigated by the phosphate-binding protein (PBP), the initial receptor for the ATP-binding cassette (ABC) phosphate transporter. In the crystal structure of the PBP–phosphate complex, the phosphate is completely desolvated and sequestered in a deep cleft and is bound by 13 hydrogen bonds: 12 to protein NH and OH donor groups and one to a carboxylate acceptor group. The carboxylate plays a key recognition role by accepting a phosphate hydrogen. PBP phosphate affinity is relatively consistent across a broad pH range, indicating the capacity to bind monobasic (H2PO4 −) and dibasic (HPO4 2−) phosphate; however, the mechanism by which it might accommodate the second hydrogen of monobasic phosphate is unclear. To answer this question, neutron diffraction studies were initiated. Large single crystals with a volume of 8 mm3 were grown and subjected to hydrogen/deuterium exchange. A 2.5 Å resolution data set was collected on the Protein Crystallography Station at the Los Alamos Neutron Science Center. Initial refinement of the neutron data shows significant nuclear density, and refinement is ongoing. This is the first report of a neutron study from this superfamily. PMID:24915101

  9. Environmental surveillance at Los Alamos during 1979

    SciTech Connect

    Not Available

    1980-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos Scientific Laboratory (LASL) in 1979. Routine monitoring for radiation and radioactive or chemical substances was conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of the data for 1979 on penetrating radiation, chemical and radiochemical quality of ambient air, surface and ground water, municipal water supply, soils and sediments, food, and airborne and liquid effluents are included. Comparisons with appropriate standards and regulations or with background levels from natural or other non-LASL sources provide a basis for concluding that environmental effects attributable to LASL operations are minor and cannot be considered likely to result in any hazard to the population of the area. Results of several special studies provide documentation of some unique environmental conditions in the LASL environs.

  10. Environmental surveillance at Los Alamos during 1992

    SciTech Connect

    Kohen, K.; Stoker, A.; Stone, G.

    1994-07-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory during 1992. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring results to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1992 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, laboratory employees, or the environment.

  11. Foreign National Involvement at Los Alamos

    NASA Astrophysics Data System (ADS)

    Wilhelmy, Jerry

    2000-04-01

    Since the beginning of the spring of 1999 there has been an intense national media focus on alleged security breaches by a foreign born scientist employed at LANL. Alarmed by an apparent growing sense of xenophobia, the Fellows of the Los Alamos National Laboratory addressed this issue by preparing a white paper on Foreign National Involvement at LANL (www.fellows.lanl.gov). Its purpose was to recognize and acknowledge the vital role that foreign scientists have played and continue to play in making LANL a forefront scientific institution. This legacy will be discussed, as well as concerns that constraining regulations triggered by this episode and subsequent reactions to this by our scientific peer community could have long term consequences on the vitality of the Laboratory.

  12. Environmental surveillance at Los Alamos during 1989

    SciTech Connect

    Not Available

    1990-12-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1989. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1989 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment. 58 refs., 31 figs., 39 tabs.

  13. Environmental surveillance at Los Alamos during 1995

    SciTech Connect

    1996-10-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory (LANL or the Laboratory) during 1995. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring result to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1995 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, Laboratory employees, or the environment.

  14. Environmental surveillance at Los Alamos during 1987

    SciTech Connect

    Not Available

    1988-05-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1987. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1987 cover: external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are insignificant and do not pose a threat to the public, Laboratory employees, or the environment. 113 refs., 33 figs., 120 tabs.

  15. Los Alamos National Laboratory transuranic database analysis

    SciTech Connect

    Christensen, D.V.; Rogers, P.S.Z.; Kosiewicz, S.T.; LeBrun, D.B.

    1997-02-01

    This paper represents an overview of analyses conducted on the TRU database maintained by the Los Alamos National Laboratory (LANL). This evaluation was conducted to support the ``TRU Waste Workoff Strategies`` document and provides an estimation of the waste volume that potentially could be certified and ready for shipment to (WIPP) in April of 1998. Criteria defined in the WIPP WAC, including container type, weight limits, plutonium fissile gram equivalents and decay heat, were used to evaluated the waste for compliance. LANL evaluated the containers by facility and by waste stream to determining the most efficient plan for characterization and certification of the waste. Evaluation of the waste presently in storage suggested that 40- 60% potentially meets the WIPP WAC Rev. 5 criteria.

  16. A scintillating fission detector for neutron flux measurements

    SciTech Connect

    Stange, Sy; Esch, Ernst I; Burgett, Eric A; May, Iain; Muenchausen, Ross E; Taw, Felicia; Tovesson, Fredrik K

    2010-01-01

    Neutron flux monitors are commonly used for a variety of nuclear physics applications. A scintillating neutron detector, consisting of a liquid scintillator loaded with fissionable material, has been developed, characterized, and tested in the beam line at the Los Alamos Neutron Science Center, and shows a significant improvement in neutron sensitivity compared with a conventional fission chamber. Recent research on nanocomposite-based scintillators for gamma-ray detection indicates that this approach can be extended to load nanoparticles of fissionable material into a scintillating matrix, with up to three orders of magnitude higher loading than typical fission chambers. This will result in a rugged, cost-efficient detector with high efficiency, a short signal rise time, and the ability to be used in low neutron-flux environments. Initial efforts to utilize the luminescence of uranyl oxide to eliminate the need for wavelength-shifting dyes were unsuccessful. Excitation of uranyl compounds has been reported at wavelengths ranging from 266 nm to 532 nm. However, neither the 300 nm emission of toluene, nor the 350 nm emission of PPO, nor the 410 nm emission of POPOP resulted in significant excitation of and emission by uranyl oxide. As indicated by UV/visible spectroscopy, light emitted at these wavelengths was absorbed by the colored solution. {sup 235}U remains the most attractive candidate for a fissionable scintillator, due to its high fission cross-section and lack of a threshold fission energy, but all solutions containing molecular uranium compounds will be colored, most more highly than the U{sup 6+} compounds used here. Research is therefore continuing toward the fabrication of uranium nanoparticles, in which, due to Rayleigh scattering, the coloration should be less pronounced. The characterization of the thorium-loaded liquid scintillator and the fabrication of the 100 mL detectors for use at LANSCE demonstrated the feasibility of loading fissionable

  17. Neutron interactions in the CUORE neutrinoless double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Dolinski, Michelle Jean

    Neutrinoless double beta decay (0nuDBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0nuDBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0nuDBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0nuDBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0nuDBD of 130Te with a ton-scale array of unenriched TeO2 bolometers. By increasing mass and decreasing the background for 0nuDBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10-6. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0nuDBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, winch can be produced underground both by (alpha,n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE data to set an upper

  18. Neutron Interactions in the CUORE Neutrinoless Double Beta Decay Experiment

    SciTech Connect

    Dolinski, Michelle Jean

    2008-10-01

    Neutrinoless double beta decay (0vDBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0vDBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0vDBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0vDBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0vDBD of 130Te with a ton-scale array of unenriched TeO2 bolometers. By increasing mass and decreasing the background for 0vDBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10-6. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0vDBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, which can be produced underground both by (α,n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE

  19. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Couture, A.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Stoyer, M. A.; Wu, C. Y.; Becker, J. A.; Haslett, R. J.; Henderson, R. A.

    2009-01-28

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) events from (n,f) events. The first direct observation of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  20. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    SciTech Connect

    Jandel, Marian

    2008-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  1. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    SciTech Connect

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

  2. Environmental surveillance at Los Alamos during 2008

    SciTech Connect

    Fuehne, David; Gallagher, Pat; Hjeresen, Denny; Isaacson, John; Johson, Scot; Morgan, Terry; Paulson, David; Rogers, David

    2009-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Programs Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information.

  3. Environmental surveillance at Los Alamos during 2005

    SciTech Connect

    2006-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (LANL or the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.IA, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory's efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory's major environmental programs. Chapter 2 reports the Laboratory's compliance status for 2005. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, Air; Chapters 5 and 6, Water and Sediments; Chapter 7, Soils; and Chapter 8, Foodstuffs and Biota) in a format to meet the needs of a general and scientific audience. Chapter 9, new for this year, provides a summary of the status of environmental restoration work around LANL. A glossary and a list ofacronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory's technical areas and their associated programs, and Appendix D provides web links to more information.

  4. Environmental surveillance at Los Alamos during 2009

    SciTech Connect

    Fuehne, David; Poff, Ben; Hjeresen, Denny; Isaacson, John; Johnson, Scot; Morgan, Terry; Paulson, David; Salzman, Sonja; Rogers, David

    2010-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2009. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (air in Chapter 4; water and sediments in Chapters 5 and 6; soils in Chapter 7; and foodstuffs and biota in Chapter 8) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. The new Chapter 10 describes the Laboratory’s environmental stewardship efforts and provides an overview of the health of the Rio Grande. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical

  5. 2015 Los Alamos Space Weather Summer School Research Reports

    SciTech Connect

    Cowee, Misa; Chen, Yuxi; Desai, Ravindra; Hassan, Ehab; Kalmoni, Nadine; Lin, Dong; Depascuale, Sebastian; Hughes, Randall Scott; Zhou, Hong

    2015-11-24

    The fifth Los Alamos Space Weather Summer School was held June 1st - July 24th, 2015, at Los Alamos National Laboratory (LANL). With renewed support from the Institute of Geophysics, Planetary Physics, and Signatures (IGPPS) and additional support from the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) Office of Science, we hosted a new class of five students from various U.S. and foreign research institutions. The summer school curriculum includes a series of structured lectures as well as mentored research and practicum opportunities. Lecture topics including general and specialized topics in the field of space weather were given by a number of researchers affiliated with LANL. Students were given the opportunity to engage in research projects through a mentored practicum experience. Each student works with one or more LANL-affiliated mentors to execute a collaborative research project, typically linked with a larger ongoing research effort at LANL and/or the student’s PhD thesis research. This model provides a valuable learning experience for the student while developing the opportunity for future collaboration. This report includes a summary of the research efforts fostered and facilitated by the Space Weather Summer School. These reports should be viewed as work-in-progress as the short session typically only offers sufficient time for preliminary results. At the close of the summer school session, students present a summary of their research efforts. Titles of the papers included in this report are as follows: Full particle-in-cell (PIC) simulation of whistler wave generation, Hybrid simulations of the right-hand ion cyclotron anisotropy instability in a sub-Alfvénic plasma flow, A statistical ensemble for solar wind measurements, Observations and models of substorm injection dispersion patterns, Heavy ion effects on Kelvin-Helmholtz instability: hybrid study, Simulating plasmaspheric electron densities with a two

  6. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  7. INTEGRATED MONITORING HARDWARE DEVELOPMENTS AT LOS ALAMOS

    SciTech Connect

    R. PARKER; J. HALBIG; ET AL

    1999-09-01

    The hardware of the integrated monitoring system supports a family of instruments having a common internal architecture and firmware. Instruments can be easily configured from application-specific personality boards combined with common master-processor and high- and low-voltage power supply boards, and basic operating firmware. The instruments are designed to function autonomously to survive power and communication outages and to adapt to changing conditions. The personality boards allow measurement of gross gammas and neutrons, neutron coincidence and multiplicity, and gamma spectra. In addition, the Intelligent Local Node (ILON) provides a moderate-bandwidth network to tie together instruments, sensors, and computers.

  8. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  9. Neutron dosimetry

    DOEpatents

    Quinby, Thomas C.

    1976-07-27

    A method of measuring neutron radiation within a nuclear reactor is provided. A sintered oxide wire is disposed within the reactor and exposed to neutron radiation. The induced radioactivity is measured to provide an indication of the neutron energy and flux within the reactor.

  10. Final Environmental Impact Statement for the Conveyance and Transfer of Certain Land Tracts Administered by the U.S. Department of Energy and Located at Los Alamos National Laboratory, Los Alamos and Santa Fe Counties, New Mexico

    SciTech Connect

    N /A

    2000-02-04

    Los Alamos National Laboratory (LANL) is one of several national laboratories that supports the U.S. Department of Energy's (DOE's) responsibilities for national security, energy resources, environmental quality, and science. LANL is located in north-central New Mexico, within Los Alamos County and Santa Fe County, about 60 miles (97 kilometers) north-northeast of Albuquerque and about 25 miles (40 kilometers) northwest of Santa Fe. The small communities of Los Alamos townsite, White Rock, Pajarito Acres, the Royal Crest Mobile Home Park, and San Ildefonso Pueblo are located in the immediate vicinity of LANL. On November 26, 1997, Congress passed Public Law (PL) 105-119, the ''Departments of Commerce, Justice, and State, the Judiciary, and Related Agencies Appropriations Act'', 1998 (Section 632, 42 United States Code [U.S.C.] Section 2391; ''the Act''), which directs the DOE to convey or transfer parcels of DOE land in the vicinity of LANL to the Incorporated County of Los Alamos, New Mexico, and the Secretary of the Interior, in trust for the Pueblo of San Ildefonso. Such parcels, or tracts, of land must not be required to meet the national security mission of the DOE and must also meet other criteria established by the Act.

  11. Energy, information science, and systems science

    SciTech Connect

    Wallace, Terry C; Mercer - Smith, Janet A

    2011-02-01

    This presentation will discuss global trends in population, energy consumption, temperature changes, carbon dioxide emissions, and energy security programs at Los Alamos National Laboratory. LANL's capabilities support vital national security missions and plans for the future. LANL science supports the energy security focus areas of impacts of Energy Demand Growth, Sustainable Nuclear Energy, and Concepts and Materials for Clean Energy. The innovation pipeline at LANL spans discovery research through technology maturation and deployment. The Lab's climate science capabilities address major issues. Examples of modeling and simulation for the Coupled Ocean and Sea Ice Model (COSIM) and interactions of turbine wind blades and turbulence will be given.

  12. The Fundamental Neutron Physics Facilities at NIST

    PubMed Central

    Nico, J. S.; Arif, M.; Dewey, M. S.; Gentile, T. R.; Gilliam, D. M.; Huffman, P. R.; Jacobson, D. L.; Thompson, A. K.

    2005-01-01

    The program in fundamental neutron physics at the National Institute of Standards and Technology (NIST) began nearly two decades ago. The Neutron Interactions and Dosimetry Group currently maintains four neutron beam lines dedicated to studies of fundamental neutron interactions. The neutrons are provided by the NIST Center for Neutron Research, a national user facility for studies that include condensed matter physics, materials science, nuclear chemistry, and biological science. The beam lines for fundamental physics experiments include a high-intensity polychromatic beam, a 0.496 nm monochromatic beam, a 0.89 nm monochromatic beam, and a neutron interferometer and optics facility. This paper discusses some of the parameters of the beam lines along with brief presentations of some of the experiments performed at the facilities. PMID:27308110

  13. FY results for the Los Alamos large scale demonstration and deployment project

    SciTech Connect

    Stallings, E.; McFee, J.

    2000-11-01

    The Los Alamos Large Scale Demonstration and Deployment Project (LSDDP) in support of the US Department of Energy (DOE) Deactivation and Decommissioning Focus Area (DDFA) is identifying and demonstrating technologies to reduce the cost and risk of management of transuranic element contaminated large metal objects, i.e. gloveboxes. DOE must dispose of hundreds of gloveboxes from Rocky Flats, Los Alamos and other DOE sites. Current practices for removal, decontamination and size reduction of large metal objects translates to a DOE system-wide cost in excess of $800 million, without disposal costs. In FY99 and FY00 the Los Alamos LSDDP performed several demonstrations on cost/risk savings technologies. Commercial air pallets were demonstrated for movement and positioning of the oversized crates in neutron counting equipment. The air pallets are able to cost effectively address the complete waste management inventory, whereas the baseline wheeled carts could address only 25% of the inventory with higher manpower costs. A gamma interrogation radiography technology was demonstrated to support characterization of the crates. The technology was developed for radiography of trucks for identification of contraband. The radiographs were extremely useful in guiding the selection and method for opening very large crated metal objects. The cost of the radiography was small and the operating benefit is high. Another demonstration compared a Blade Cutting Plunger and reciprocating saw for removal of glovebox legs and appurtenances. The cost comparison showed that the Blade Cutting Plunger costs were comparable, and a significant safety advantage was reported. A second radiography demonstration was conducted evaluation of a technology based on WIPP-type x-ray characterization of large boxes. This technology provides considerable detail of the contents of the crates. The technology identified details as small as the fasteners in the crates, an unpunctured aerosol can, and a vessel

  14. Science and Society. A Complex Interaction

    ERIC Educational Resources Information Center

    Rosen, Louis

    1973-01-01

    Describes controversial examples attributed to the pursuit of science and research activities conducted by the Los Alamos Scientific Laboratory to solve present major physical problems. Indicates the necessity of convincing society that untrammeled investigation in science is the only path to derivation of practical public benefits. (CC)

  15. Neutron multiplication error in TRU waste measurements

    SciTech Connect

    Veilleux, John; Stanfield, Sean B; Wachter, Joe; Ceo, Bob

    2009-01-01

    more realistic and accurate. To do so, measurements of standards and waste drums were performed with High Efficiency Neutron Counters (HENC) located at Los Alamos National Laboratory (LANL). The data were analyzed for multiplication effects and new estimates of the multiplication error were computed. A concluding section will present alternatives for reducing the number of rejections of TRU waste containers due to neutron multiplication error.

  16. Nondestructive Assay of TRU Waste Sludge at Los Alamos National Laboratory

    SciTech Connect

    Wachter, J.R.; Stanfield, S.B.; Veilleux, J.M.

    2006-07-01

    Nondestructive assay (NDA) measurements of Transuranic (TRU) sludge waste at Los Alamos National Laboratory (LANL) shares many of the same measurement complexities that have been encountered at other DOE sites. The sludge matrix is highly attenuating to both gamma rays and neutrons, the homogeneity of matrix and source material inside the drums cannot be verified for every drum, there are no representative standards for sludges, and independent tests intended to ascertain the accuracy of the measurements are not characteristic of the waste form. At LANL, a single instrument has been used to explore the appropriateness of both passive neutron and quantitative gamma ray methods for measuring sludge drums. The passive neutron approach uses the Reals coincidence count rate to establish plutonium mass and other parameters of interest for TRU waste. The quantitative gamma ray method assumes a homogeneous distribution of matrix and source material and assays the drum with a calibration based on the known density of the matrix. Both methods are supplemented by a simultaneous isotopic measurement using Multi-Group Analysis (MGA) to determine the plutonium isotopic composition. This report will discuss the two methods in detail. Included in the discussion will be descriptions of the setup parameters and calibration techniques for the instrument. Then an evaluation of the measurement results, including a summary of the checks and tests that are applied to sludges, will be presented. Finally, a brief discussion of the conclusions that can be drawn from the tests will be offered. (authors)

  17. The performance of neutron scattering spectrometers at a long-pulse spallation source

    SciTech Connect

    Pynn, R.

    1997-06-01

    In this document the author considers the performance of a long pulse spallation source for those neutron scattering experiments that are usually performed with a monochromatic beam at a continuous wave (CW) source such as a nuclear reactor. The first conclusion drawn is that comparison of the performance of neutron scattering spectrometers at CW and pulsed sources is simpler for long-pulsed sources than it is for the short-pulse variety. Even though detailed instrument design and assessment will require Monte Carlo simulations (which have already been performed at Los Alamos for SANS and reflectometry), simple arguments are sufficient to assess the approximate performance of spectrometers at an LPSS and to support the contention that a 1 MW long-pulse source can provide attractive performance, especially for instrumentation designed for soft-condensed-matter science. Because coupled moderators can be exploited at such a source, its time average cold flux is equivalent to that of a research reactor with a power of about 15 MW, so only a factor of 4 gain from source pulsing is necessary to obtain performance that is comparable with the ILL. In favorable cases, the gain from pulsing can be even more than this, approaching the limit set by the peak flux, giving about 4 times the performance of the ILL. Because of its low duty factor, an LPSS provides the greatest performance gains for relatively low resolution experiments with cold neutrons. It should thus be considered complementary to short pulse sources which are most effective for high resolution experiments using thermal or epithermal neutrons.

  18. Calibration of a Bonner sphere extension (BSE) for high-energy neutron spectrometry

    PubMed Central

    Howell, R.M.; Burgett, E.A.; Wiegel, B.; Hertel, N.E.

    2011-01-01

    In a recent work, we constructed modular multisphere system which expands upon the design of an existing, commercially available Bonner sphere system by adding concentric shells of copper, tungsten, or lead. Our modular multisphere system is referred to as the Bonner Sphere Extension (BSE). The BSE was tested in a high energy neutron beam (thermal to 800 MeV) at Los Alamos Neutron Science Center and provided improvement in the measurement of the neutron spectrum in the energy regions above 20 MeV when compared to the standard BSS (Burgett, 2008 and Howell et al., 2009). However, when the initial test of the system was carried-out at LANSCE, the BSE had not yet been calibrated. Therefore the objective of the present study was to perform calibration measurements. These calibration measurements were carried out using monoenergetic neutron ISO 8529-1 reference beams at the Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany. The following monoenergetic reference beams were used for these experiments: 14.8 MeV, 1.2 MeV, 565 keV, and 144 keV. Response functions for the BSE were calculated using the Monte Carlo N-Particle Code, eXtended (MCNPX). The percent difference between the measured and calculated responses was calculated for each sphere and energy. The difference between measured and calculated responses for individual spheres ranged between 7.9 % and 16.7 % and the arithmetic mean for all spheres was (10.9 ± 1.8) %. These sphere specific correction factors will be applied for all future measurements carried-out with the BSE. PMID:22888283

  19. Parity violation in neutron-proton capture—The NPDGamma experiment

    NASA Astrophysics Data System (ADS)

    Gericke, Michael; Page, S.; Ramsay, D.; Alarcon, R.; Balascuta, S.; Barron, L.; Bowman, J. D.; Carlini, R. D.; Chen, W.; Chupp, T. E.; Crawford, C.; Covrig, S.; Dabaghyan, M.; Freedman, S. J.; Gentile, T. R.; Gillis, R. C.; Greene, G. L.; Hersman, F. W.; Ino, T.; Jones, G. L.; Lauss, B.; Leuschner, M.; Losowki, B.; Mahurin, R.; Masuda, Y.; Mei, J.; Mitchell, G. S.; Muto, S.; Nann, H.; Penttilä, S. I.; Salas-Bacci, A.; Santra, S.; Seo, P.-N.; Sharapov, E.; Sharma, M.; Smith, T.; Snow, W. M.; Wilburn, W. S.; Yuan, V.

    2009-12-01

    The NPDGamma collaboration has recently completed the first phase of a measurement to determine the size of the weak nucleon-nucleon interaction from cold neutron capture on a liquid hydrogen target. In the framework of the nearly 30 year old DDH model [B. Desplanques, J.F. Donoghue, B.R. Holstein, Annals of Physics 124 (1980) 449], the measured process is explained in terms of the weak pion-nucleon coupling, while the framework of modern effective field theory parameterizes the measured process in terms of the S13-P13, long range transition (essentially the Danilov parameter ρt) [S.L. Zhu et al., Nuclear Physics A 748 (2005) 435; C.-P. Liu, Phys. Rev. C 75 (2007) 065501]. The couplings in terms of either model are directly proportional to the parity violating up-down asymmetry in the angular distribution of gamma rays with respect to the neutron spin direction in the reaction n⇒+p→d+γ. The asymmetry has a predicted size of 5×10-8 and the aim of the NPDGamma collaboration is to measure it to 20%. The first phase of the measurement was completed at the Los Alamos National Laboratory Neutron Science Center Spallation Source with a preliminary result of (-1.1±2.1 stat.±0.2 sys.)×10-7. Here, we report on the measurements and the results obtained so far. The experiment is currently being installed at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, for the remainder of its run time.

  20. Neutron spectrum measurements using proton recoil proportional counters: results of measurements of leakage spectra for the Little Boy assembly

    SciTech Connect

    Bennett, E.F.; Yule, T.J.

    1984-01-01

    Measurements of degraded fission-neutron spectra using recoil proportional counters are done routinely for studies involving fast reactor mockups. The same techniques are applicable to measurements of neutron spectra required for personnel dosimetry in fast neutron environments. A brief discussion of current applications of these methods together with the results of a measurement made on the LITTLE BOY assembly at Los Alamos are here described.

  1. Neutron Capture Experiments on Unstable Nuclei

    SciTech Connect

    Jon M. Schwantes; Ralf Sudowe; Heino Nitsche; Darleane C. Hoffman

    2003-12-16

    A primary objective of this project is to study neutron capture cross sections for various stable and unstable isotopes that will contribute to the Science Based Stockpile Stewardship (SBSS) program by providing improved data for modeling and interpretation of nuclear device performance. The information obtained will also be important in astrophysical modeling of nucleosynthesis. During this reporting period, the emphasis has been on preparing a radioactive target of {sup 155}Eu (half-life = 4.7 years), and several stable targets, including isotopically separated {sup 154}Sm, {sup 151}Eu, and {sup 153}Eu. Measurements of their neutron capture cross sections will be conducted in collaboration with researchers at the Los Alamos Neutron Science Center (LANSCE) facility using the Detector for Advanced Neutron Capture Experiments (DANCE). A suitable backing material (beryllium) for the targets has been selected after careful calculations of its contribution to the background of the measurements. In addition, a high voltage plating procedure has been developed and optimized. Stable targets of {sup 151}Eu and {sup 153}Eu and a target of natural Eu ({approx}50% {sup 151}Eu and {approx}50% {sup 153}Eu) have each been plated to a mass thickness of >1 mg/cm{sup 2} and delivered to the DANCE collaboration at Los Alamos National Laboratory (LANL). Natural Eu targets will be tested first to confirm that the target dimensions and backing are appropriate prior to performing measurements on the extremely valuable targets of separated isotopes. In order to prepare a target of the radioactive {sup 155}Eu, it must first be separated from the {sup 154}Sm target material that was irradiated in a very high neutron flux of 1.5x1015 neutrons/cm{sup 2}/s for 50 days. The reaction is {sup 154}Sm (n,f){sup 155}Sm (half-life = 22 minutes) {sup 155}Eu. Considerable progress has been made in developing a suitable high-yield and high-purity separation method for separating Eu from targets

  2. Elastic and Inelastic Scattering of Neutrons from Neon and Argon: Impact on Neutrinoless Double-Beta Decay and Dark Matter Experimental Programs

    NASA Astrophysics Data System (ADS)

    MacMullin, Sean Patrick

    In underground physics experiments, such as neutrinoless double-beta decay and dark matter searches, fast neutrons may be the dominant and potentially irreducible source of background. Experimental data for the elastic and inelastic scattering cross sections of neutrons from argon and neon, which are target and shielding materials of interest to the dark matter and neutrinoless double-beta decay communities, were previously unavailable. Unmeasured neutron scattering cross sections are often accounted for incorrectly in Monte-Carlo simulations. Elastic scattering cross sections were measured at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. Angular distributions for neon were measured at 5.0 and 8.0 MeV. One full angular distribution was measured for argon at 6.0 MeV. The cross-section data were compared to calculations using a global optical model. Data were also fit using the spherical optical model. These model fits were used to predict the elastic scattering cross section at unmeasured energies and also provide a benchmark where the global optical models are not well constrained. Partial gamma-ray production cross sections for (n,xngamma ) reactions in natural argon and neon were measured using the broad spectrum neutron beam at the Los Alamos Neutron Science Center (LANSCE). Neutron energies were determined using time of flight and resulting gamma rays from neutron-induced reactions were detected using the GErmanium Array for Neutron Induced Excitations (GEANIE). Partial gamma-ray production cross sections for six transitions in 40Ar, two transitions in 39Ar and the first excited state transitions is 20Ne and 22Ne were measured from threshold to a neutron energy where the gamma-ray yield dropped below the detection sensitivity. Measured (n,xngamma) cross sections were compared with calculations using the TALYS and CoH3 nuclear reaction codes. These new measurements will help to identify potential backgrounds in

  3. Review of liquid metal heat pipe work at Los Alamos

    SciTech Connect

    Reid, R.S.; Merrigan, M.A.; Sena, J.T.

    1990-01-01

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs.

  4. Explosive Flux Compression: 50 Years of Los Alamos Activities

    SciTech Connect

    Fowler, C.M.; Thomson, D.B.; Garn, W.B.

    1998-10-18

    Los Alamos flux compression activities are surveyed, mainly through references in view of space limitations. However, two plasma physics programs done with Sandia National Laboratory are discussed in more detail.

  5. Environmental Surveillance at Los Alamos during 2007

    SciTech Connect

    2008-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information. In printed copies of this report or Executive Summary, we have

  6. Neutron capture by hook or by crook

    NASA Astrophysics Data System (ADS)

    Mosby, Shea

    2016-03-01

    The neutron capture reaction is a topic of fundamental interest for both heavy element (A>60) nucleosynthesis and applications in such fields as nuclear energy and defense. The full suite of interesting isotopes ranges from stable nuclei to the most exotic, and it is not possible to directly measure all the relevant reaction rates. The DANCE instrument at Los Alamos provides direct access to the neutron capture reaction for stable and long-lived nuclei, while Apollo coupled to HELIOS at Argonne has been developed as an indirect probe for cases where a direct measurement is impossible. The basic techniques and their implications will be presented, and the status of ongoing experimental campaigns to address neutron capture in the A=60 and A=100 mass regions will be discussed.

  7. Dose algorithm determination for the Los Alamos National Laboratory personnel dosimetry system

    SciTech Connect

    Patterson, J.M.

    1995-12-31

    One of the most important aspects of a TLD dosimetry system is the dose algorithm used to convert the signals from the badge reader to an estimate of a worker`s dose. It is now more important then ever to have an accurate algorithm to estimate dose well below regulatory limits. Dosimetry systems for DOE laboratories must meet minimum performance standards based on DOELAP criteria. The purpose of this paper is to describe the development of a dose algorithm for a new TLD dosimeter that has been developed at Los Alamos National Laboratories. It is expected that DOELAP testing will start in 1995. Initial results indicate that the system will be able to exceed the minimum performance criteria by a large margin. The enhanced ability of the dosimeter to determine beta, gamma, and neutron energies makes it very useful in the various radiation fields encountered at the laboratory.

  8. Seismic engineering for an expanded tritium facility at Los Alamos National Laboratory.

    SciTech Connect

    Volkman, D.E.; Olive, W.B.; Endebrocid, E.E.; Khan, P.K.; Rebillet, W.R.

    1997-10-01

    An existing complex of three single story concrete and masonry shear wall buildings will be integrated into an expanded tritium facility for neutron tube target loading. Known as the NTTL Project, the expanded plant is a major element of the Department of Energy`s tritium program at the Los Alamos National Laboratory. This paper describes seismic evaluation and upgrade modifications for the 1950`s concrete shear wall building; drift analyses of two 1980`s CMU [concrete masonry unit] shear wall buildings; design of a new CMU shear wall building linking existing structures and providing personnel change room services; and design of a new steel frame building housing HVAC and electrical power and communication equipment for the complex. All buildings are closely adjacent and drift analysis to establish separation to prevent pounding is a major seismic engineering concern for the project.

  9. Robert Serber's 1943 Los Alamos Primer Analysis of Fission Bomb Efficiency

    NASA Astrophysics Data System (ADS)

    Reed, Cameron

    2013-04-01

    In an analysis of the expected efficiency of a fission bomb presented in his 1943 Los Alamos Primer, Robert Serber remarked that ``it is just possible for the reaction to occur to an interesting extent before it is stopped by the spreading of the active material.'' Due to the exponential nature of the time-dependence of a chain reaction, the efficiency of the explosion can be very sensitive to parameters such as the number of neutrons liberated per fission, the fission cross-section, and the number of critical masses of material used. In this paper I examine efficiency predictions for both uranium and plutonium bombs. Had some parameter values proven only modestly different from their true values, history may well have been very different.

  10. Shielding calculations and verifications for the new Radiation Instrument Calibration Facility at Los Alamos National Laboratory

    SciTech Connect

    George, G. L.; Olsher, R. H.; Seagraves, D. T.

    2002-01-01

    MCNP-4C1 was used to perform the shielding design for the new Central Health Physics Calibration Facility (CHPCF) at Los Alamos National Laboratory (LANL). The problem of shielding the facility was subdivided into three separate components: (1) Transmission; (2) Skyshine; and (3) Maze Streaming/ Transmission. When possible, actual measurements were taken to verify calculation results. The comparison of calculation versus measurement results shows excellent agreement for neutron calculations. For photon comparisons, calculations resulted in conservative estimates of the Effective Dose Equivalent (EDE) compared to measured results. This disagreement in the photon measurements versus calculations is most likely due to several conservative assumptions regarding shield density and composition. For example, reinforcing steel bars (Rebar) in the concrete shield walls were not included in the shield model.

  11. Prompt fission neutron spectra in fast-neutron-induced fission of 238U

    NASA Astrophysics Data System (ADS)

    Desai, V. V.; Nayak, B. K.; Saxena, A.; Suryanarayana, S. V.; Capote, R.

    2015-07-01

    Prompt fission neutron spectrum (PFNS) measurements for the neutron-induced fission of 238U are carried out at incident neutron energies of 2.0, 2.5, and 3.0 MeV, respectively. The time-of-flight technique is employed to determine the energy of fission neutrons. The prompt fission neutron energy spectra so obtained are analyzed using Watt parametrization to derive the neutron multiplicity and average prompt fission neutron energy. The present experimental PFNS data are compared with the evaluated spectra taken from the ENDF/B-VII.1 library and the predictive calculations carried out using the empire-3.2 (Malta) code with built-in Los Alamos (LA) and Kornilov PFNS models. The sensitivity of the empire-3.2 LA model-calculated PFNS to the nuclear level density parameter of the average fission fragment and to the total kinetic energy is investigated. empire-3.2 LA model PFNS calculations that use Madland 2006-recommended values [D. G. Madland, Nucl. Phys. A 772, 113 (2006), 10.1016/j.nuclphysa.2006.03.013] of the total kinetic energy and the level density parameter a =A /(10 ±0.5 ) compare very well to measured data at all incident neutron incident energies.

  12. On the Measurement of the Neutron Lifetime Using Ultracold Neutrons in a Vacuum Quadrupole Trap

    PubMed Central

    Bowman, J. David; Penttila, S. I.

    2005-01-01

    We present a conceptual design for an experiment to measure the neutron lifetime (~886 s) with an accuracy of 10−4. The lifetime will be measured by observing the decay rate of a sample of ultracold neutrons (UCN) confined in vacuum in a magnetic trap. The UCN collaboration at Los Alamos National Laboratory has developed a prototype UCN source that is expected to produce a bottled UCN density of more than 100/cm3 [1]. The availability of such an intense source makes it possible to approach the measurement of the neutron lifetime in a new way. We argue below that it is possible to measure the neutron lifetime to 10−4 in a vacuum magnetic trap. The measurement involves no new technology beyond the expected UCN density. If even higher densities are available, the experiment can be made better and/or less expensive. We present the design and methodology for the measurement. The slow loss of neutrons that have stable orbits, but are not energetically trapped would produce a systematic uncertainty in the measurement. We discuss a new approach, chaotic cleaning, to the elimination of quasi-neutrons from the trap by breaking the rotational symmetry of the quadrupole trap. The neutron orbits take on a chaotic character and mode mixing causes the neutrons on the quasi-bound orbits to leave the trap. PMID:27308151

  13. Improved Modeling of Prompt Fission Neutron Spectra for Nuclear Data Evaluations

    NASA Astrophysics Data System (ADS)

    Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko; Kahler, Albert C.; White, Morgan C.

    2015-10-01

    The prompt fission neutron spectra (PFNS) of major actinides such as 239Pu and 235U are quantities of interest for nuclear physics application areas including reactor physics and national security. Nuclear data evaluations provide recommended data for those application areas based on nuclear theory and experiments. Here, we present improvements made to the effective models predicting the PFNS up to incident neutron energies of 30 MeV and their impact on evaluations. These models describe relevant physics processes better than those used for the current US nuclear data library ENDF/B-VII.1. In addition, the use of higher-fidelity models such as Monte Carlo Hauser-Feshbach calculations will be discussed in the context of future PFNS evaluations. (LA-UR-15-24763) This work was carried out under the auspices of the US Department of Energy, National Nuclear Security Administration and Office of Science, and performed by Los Alamos National Security LLC under Contract DE-AC52-06NA25396.

  14. Long-term Passive Mode Data Measured by the Dynamic Albedo of Neutrons (DAN) Instrument onboard Mars Science Laboratory (MSL) and Comparison to REMS Surface Pressure and Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B.; Martín-Torres, J.; Zorzano, M. P.; Boynton, W. V.; Fedosov, F.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A. V.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Tate, C. G.

    2014-12-01

    Since the landing in August 2012, DAN has provided a wealth of scientific data from the successful surface operation in both Active mode and Passive mode. While the main DAN science investigation so far has focused in estimating the contents of water-equivalent-hydrogen (WEH) and chlorine-equivalent-neutron-absorption in the surface, here we will provide/discuss low energy (less than about 1 keV) background neutron environment at the Martian surface as measured by DAN Passive mode operation. Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Neutrons from the onboard power source Multi Mission Radioisotope Thermonuclear Generator (MMRTG) and induced by Galactic Cosmic Ray (GCR)/Solar Energetic Particles (SEP) interactions with the Martian atmosphere and the surface material contribute to the DAN passive data. An approach to separate out the respective contributions from the DAN total count rates was developed previously (Jun et al., 2013) using the data collected at Rocknest (where the rover stayed from sol 60 to sol 100). The main goal of this paper is to extend the same analysis to other locations encountered during the rover traverse especially to understand the long-term (through Sol 800, covering more than 1 Martian year) behavior of the neutron environment at the Martian surface as measured by DAN in response to variation of the free space GCR/SEP environment. Extensive Monte Carlo transport simulations using Monte Carlo N-Particle eXtended (MCNPX) have been performed to support the analysis and to aid interpretation of the DAN passive data. In addition, the DAN passive data are compared to the long-term surface temperature and pressure data (both measured and modeled) from Rover Environmental Monitoring Station (REMS) to investigate possible correlation of the DAN data with ambient environmental conditions.

  15. The economic impact of Los Alamos National Laboratory on North-Central New Mexico and the state of New Mexico. Fiscal Year 1995

    SciTech Connect

    Lansford, R.R.; Adcock, L.D.; Gentry, L.M.; Ben-David, S.

    1996-08-01

    Los Alamos National Laboratory is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote U.S. industrial competitiveness by working with U.S. companies in technology transfer and technology development partnerships. Los Alamos has provided technical assistance to over 70 small New Mexico businesses enabling economic development activities in the region and state.

  16. Expanded recycling at Los Alamos National Laboratory

    SciTech Connect

    Betschart, J.F.; Malinauskas, L.; Burns, M.

    1996-07-01

    The Pollution Prevention Program Office has increased recycling activities, reuse, and options to reduce the solid waste streams through streamlining efforts that applied best management practices. The program has prioritized efforts based on volume and economic considerations and has greatly increased Los Alamos National Laboratory`s (LANL`s) recycle volumes. The Pollution Prevention Program established and chairs a Solid Waste Management Solutions Group to specifically address and solve problems in nonradioactive, Resource Conservation and Recovery Act (RCRA), state-regulated, and sanitary and industrial waste streams (henceforth referred to as sanitary waste in this paper). By identifying materials with recycling potential, identifying best management practices and pathways to return materials for reuse, and introducing the concept and practice of {open_quotes}asset management,{open_quotes} the Group will divert much of the current waste stream from disposal. This Group is developing procedures, agreements, and contracts to stage, collect, sort, segregate, transport and process materials, and is also garnering support for the program through the involvement of upper management, facility managers, and generators.

  17. Saving Water at Los Alamos National Laboratory

    SciTech Connect

    Erickson, Andy

    2015-03-16

    Los Alamos National Laboratory decreased its water usage by 26 percent in 2014, with about one-third of the reduction attributable to using reclaimed water to cool a supercomputing center. The Laboratory's goal during 2014 was to use only re-purposed water to support the mission at the Strategic Computing Complex. Using reclaimed water from the Sanitary Effluent Reclamation Facility, or SERF, substantially decreased water usage and supported the overall mission. SERF collects industrial wastewater and treats it for reuse. The reclamation facility contributed more than 27 million gallons of re-purposed water to the Laboratory's computing center, a secured supercomputing facility that supports the Laboratory’s national security mission and is one of the institution’s larger water users. In addition to the strategic water reuse program at SERF, the Laboratory reduced water use in 2014 by focusing conservation efforts on areas that use the most water, upgrading to water-conserving fixtures, and repairing leaks identified in a biennial survey.

  18. Historic Manhattan Project Sites at Los Alamos

    ScienceCinema

    McGehee, Ellen

    2014-05-22

    The Manhattan Project laboratory constructed at Los Alamos, New Mexico, beginning in 1943, was intended from the start to be temporary and to go up with amazing speed. Because most of those WWII-era facilities were built with minimal materials and so quickly, much of the original infrastructure was torn down in the late '40s and early '50s and replaced by more permanent facilities. However, a few key facilities remained, and are being preserved and maintained for historic significance. Four such sites are visited briefly in this video, taking viewers to V-Site, the buildings where the first nuclear explosive device was pre-assembled in preparation for the Trinity Test in Southern New Mexico. Included is another WWII area, Gun Site. So named because it was the area where scientists and engineers tested the so-called "gun method" of assembling nuclear materials -- the fundamental design of the Little Boy weapon that was eventually dropped on Hiroshima. The video also goes to Pajarito Site, home of the "Slotin Building" and "Pond Cabin." The Slotin Building is the place where scientist Louis Slotin conducted a criticality experiment that went awry in early 1946, leading to his unfortunate death, and the Pond Cabin served the team of eminent scientist Emilio Segre who did early chemistry work on plutonium that ultimately led to the Fat Man weapon.

  19. Proportional counter as neutron detector

    NASA Technical Reports Server (NTRS)

    Braby, L. A.; Badhwar, G. D.

    2001-01-01

    A technique to separate out the dose, and lineal energy spectra of neutrons and charged particles is described. It is based on using two proportional counters, one with a wall, and the other with similar characteristics but wall made from a non-hydrogen containing material. Results of a calibration in a neutron field are also shown. c2001 Elsevier Science Ltd. All rights reserved.

  20. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  1. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect

    Abeln, Terri G.

    2012-04-25

    A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.

  2. Single event upset and charge collection measurements using high energy protons and neutrons

    SciTech Connect

    Normand, E.; Oberg, D.L.; Wert, J.L.; Ness, J.D.; Majewski, P.P. ); Wender, S.; Gavron, A. )

    1994-12-01

    RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500, and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum.

  3. Twisting Neutron Waves

    NASA Astrophysics Data System (ADS)

    Pushin, Dmitry

    Most waves encountered in nature can be given a ``twist'', so that their phase winds around an axis parallel to the direction of wave propagation. Such waves are said to possess orbital angular momentum (OAM). For quantum particles such as photons, atoms, and electrons, this corresponds to the particle wavefunction having angular momentum of Lℏ along its propagation axis. Controlled generation and detection of OAM states of photons began in the 1990s, sparking considerable interest in applications of OAM in light and matter waves. OAM states of photons have found diverse applications such as broadband data multiplexing, massive quantum entanglement, optical trapping, microscopy, quantum state determination and teleportation, and interferometry. OAM states of electron beams have been used to rotate nanoparticles, determine the chirality of crystals and for magnetic microscopy. Here I discuss the first demonstration of OAM control of neutrons. Using neutron interferometry with a spatially incoherent input beam, we show the addition and conservation of quantum angular momenta, entanglement between quantum path and OAM degrees of freedom. Neutron-based quantum information science heretofore limited to spin, path, and energy degrees of freedom, now has access to another quantized variable, and OAM modalities of light, x-ray, and electron beams are extended to a massive, penetrating neutral particle. The methods of neutron phase imprinting demonstrated here expand the toolbox available for development of phase-sensitive techniques of neutron imaging. Financial support provided by the NSERC Create and Discovery programs, CERC and the NIST Quantum Information Program is acknowledged.

  4. Compact neutron generator development at LBNL

    SciTech Connect

    Reijonen, J.; English, G.; Firestone, R.; Giquel, F.; King, M.; Leung, K-N.; Sun, M.

    2003-12-31

    A wide variety of applications ranging from medical (BNCT, Boron Neutron Capture Therapy) and basic science (neutron imaging, material studies) to homeland security (explosive detection and nuclear material non-proliferation) are in need of compact, high flux neutron generators. The Plasma and Ion Source Technology Group in the Lawrence Berkeley National Laboratory is developing various neutron generators for these applications. These neutron generators employed either the D-D or the D-T fusion reaction for the neutron production. The deuterium or deuterium-tritium gas mixture is ionized in an RF-driven plasma source. The ions are then accelerated to {approx}100 keV energy using high current, high voltage DC-power supply to a target where the 2.45 MeV (for D-D reaction) or 14 MeV (for the D-T reaction) neutrons are generated. The development of two different types of neutron tubes are being discussed in this presentation, namely compact, pulsed operation neutron generators and cw, high yield neutron generators. These generators are currently operating at D-D neutron yields of 108 n/s and 109 n/s respectively. A facility, incorporating the larger neutron generator, has been constructed for Prompt Gamma Activation Analysis (PGAA) and Neutron Activation Analysis (NAA) measurements.

  5. An Overview of the Los Alamos Program on Asteroid Mitigation by a Nuclear Explosion

    NASA Astrophysics Data System (ADS)

    Weaver, R.; Gisler, G. R.; Plesko, C. S.; Ferguson, J.

    2014-12-01

    Los Alamos National Laboratory is standing up a new program to address the mitigation of a potentially hazardous objects (PHO) by using nuclear explosives. A series of efforts at Los Alamos have been working this problem for the last few years in an informal fashion. We now have a funded program to dedicate time to this important mission. The goal of our project is to study the effectiveness of using a nuclear explosive to mitigate (alter orbit or destroy) an PHO on an Earth crossing path. We are also pursuing studies of impact hazards should the international leadership decide not to organize a mission for active mitigation of a PHO. Such impact hazards are characterized as local, regional or global. Impact hazards include: a direct hit in an urban area (potentially catastrophic but highly unlikely); the generation a significant tsunami from an ocean impact close to a coastline and regional and global effects from medium to large impactors. Previous studies at Los Alamos have looked at 2D and 3D simulations in the deep ocean from large bolides, as well as impacts that have global consequences. More recent work has included radiation-hydrodynamic simulations of momentum transfer (and enhancement) from a low energy (10 kt) stand-off source, as well as surface and subsurface high energy explosions (100 kt - 10 Mt) for example PHOs. The current program will carefully look at two main aspects of using a standoff nuclear source: 1) a computational study for the optimum height-of-burst (HOB) of a stand-off burst using our best energy coupling techniques for both neutrons and x-rays; and 2) as a function of the nuclear energy produced and the HOB what is the optimum energy field: neutrons or x-rays. This team is also working with NNSA and NASA Goddard to compare numerical results for these complicated simulations on a well defined series of test problems involving both kinetic impactors and stand-off nuclear energy sources. Results will be shown by the co-authors on

  6. Controlling neutron orbital angular momentum.

    PubMed

    Clark, Charles W; Barankov, Roman; Huber, Michael G; Arif, Muhammad; Cory, David G; Pushin, Dmitry A

    2015-09-24

    The quantized orbital angular momentum (OAM) of photons offers an additional degree of freedom and topological protection from noise. Photonic OAM states have therefore been exploited in various applications ranging from studies of quantum entanglement and quantum information science to imaging. The OAM states of electron beams have been shown to be similarly useful, for example in rotating nanoparticles and determining the chirality of crystals. However, although neutrons--as massive, penetrating and neutral particles--are important in materials characterization, quantum information and studies of the foundations of quantum mechanics, OAM control of neutrons has yet to be achieved. Here, we demonstrate OAM control of neutrons using macroscopic spiral phase plates that apply a 'twist' to an input neutron beam. The twisted neutron beams are analysed with neutron interferometry. Our techniques, applied to spatially incoherent beams, demonstrate both the addition of quantum angular momenta along the direction of propagation, effected by multiple spiral phase plates, and the conservation of topological charge with respect to uniform phase fluctuations. Neutron-based studies of quantum information science, the foundations of quantum mechanics, and scattering and imaging of magnetic, superconducting and chiral materials have until now been limited to three degrees of freedom: spin, path and energy. The optimization of OAM control, leading to well defined values of OAM, would provide an additional quantized degree of freedom for such studies. PMID:26399831

  7. Materials Capability Review Los Alamos National Laboratory April 29-May 2, 2012

    SciTech Connect

    Taylor, Antoinette J

    2012-04-20

    Los Alamos National Laboratory (LANL) uses Capability Reviews to assess the quality and institutional integration of science, technology and engineering (STE) and to advise Laboratory Management on the current and future health of LANL STE. The capabilities are deliberately chosen to be crosscutting over the Laboratory and therefore will include experimental, theoretical and simulation disciplines from multiple line organizations. Capability Reviews are designed to provide a more holistic view of the STE quality, integration to achieve mission requirements, and mission relevance. The scope of these capabilities necessitate that there will be significant overlap in technical areas covered by capability reviews (e.g., materials research and weapons science and engineering). In addition, LANL staff may be reviewed in different capability reviews because of their varied assignments and expertise. The principal product of the Capability Review is the report that includes the review committee's assessments, recommendations, and recommendations for STE.

  8. Active mode calibration of the combined thermal epithermal neutron (CTEN) system

    SciTech Connect

    Veilleux, J. M.

    2001-01-01

    The Combined Thermal Epithermal Neutron (CTEN) system was developed by the Los Alamos National Laboratory to perform active and passive neutron interrogation of waste. The higher energy epithermal neutrons are able to penetrate further into the matrix and active material, thus reducing matrix attenuation and self-shielding effects compared to a thermal neutron pulse alone. The developmental unit was installed in 2001 at the Los Alamos Non-Destructive Assay (NDA) facility to characterize waste for the TRU Waste Characterization Project (TWCP). This paper summarizes the active mode certification results. National Institute of Standards and Technology (NIST) traceable standards were used to determine the system response as a function of mass. Finally, NIST-traceable verification standards were used to verify the calibration in the range 30 milligrams to 25 g of weapons grade plutonium although self-shielding limits the upper active interrogation to 10 g.

  9. Igniting the Light Elements: The Los Alamos Thermonuclear Weapon Project, 1942-1952

    SciTech Connect

    Anne C. Fitzpatrick

    1999-07-01

    The American system of nuclear weapons research and development was conceived and developed not as a result of technological determinism, but by a number of individual architects who promoted the growth of this large technologically-based complex. While some of the technological artifacts of this system, such as the fission weapons used in World War II, have been the subject of many historical studies, their technical successors--fusion (or hydrogen) devices--are representative of the largely unstudied highly secret realms of nuclear weapons science and engineering. In the postwar period a small number of Los Alamos Scientific Laboratory's staff and affiliates were responsible for theoretical work on fusion weapons, yet the program was subject to both the provisions and constraints of the US Atomic Energy Commission, of which Los Alamos was a part. The Commission leadership's struggle to establish a mission for its network of laboratories, least of all to keep them operating, affected Los Alamos's leaders' decisions as to the course of weapons design and development projects. Adapting Thomas P. Hughes's ''large technological systems'' thesis, I focus on the technical, social, political, and human problems that nuclear weapons scientists faced while pursuing the thermonuclear project, demonstrating why the early American thermonuclear bomb project was an immensely complicated scientific and technological undertaking. I concentrate mainly on Los Alamos Scientific Laboratory's Theoretical, or T, Division, and its members' attempts to complete an accurate mathematical treatment of the ''Super''--the most difficult problem in physics in the postwar period--and other fusion weapon theories. Although tackling a theoretical problem, theoreticians had to address technical and engineering issues as well. I demonstrate the relative value and importance of H-bomb research over time in the postwar era to scientific, politician, and military participants in this project. I

  10. PREFACE: IUMRS-ICA 2008 Symposium, Sessions 'X. Applications of Synchrotron Radiation and Neutron Beam to Soft Matter Science' and 'Y. Frontier of Polymeric Nano-Soft-Materials - Precision Polymer Synthesis, Self-assembling and Their Functionalization'

    NASA Astrophysics Data System (ADS)

    Takahara, Atsushi; Kawahara, Seiichi

    2009-09-01

    Applications of Synchrotron Radiation and Neutron Beam to Soft Matter Science (Symposium X of IUMRS-ICA2008) Toshiji Kanaya, Kohji Tashiro, Kazuo Sakura Keiji Tanaka, Sono Sasaki, Naoya Torikai, Moonhor Ree, Kookheon Char, Charles C Han, Atsushi Takahara This volume contains peer-reviewed invited and contributed papers that were presented in Symposium X 'Applications of Synchrotron Radiation and Neutron Beam to Soft Matter Science' at the IUMRS International Conference in Asia 2008 (IUMRS-ICA 2008), which was held on 9-13 December 2008, at Nagoya Congress Center, Nagoya, Japan. Structure analyses of soft materials based on synchrotron radiation (SR) and neutron beam have been developed steadily. Small-angle scattering and wide-angle diffraction techniques clarified the higher-order structure as well as time dependence of structure development such as crystallization and microphase-separation. On the other hand, reflectivity, grazing-incidence scattering and diffraction techniques revealed the surface and interface structural features of soft materials. From the viewpoint of strong interests on the development of SR and neutron beam techniques for soft materials, the objective of this symposium is to provide an interdisciplinary forum for the discussion of recent advances in research, development, and applications of SR and neutron beams to soft matter science. In this symposium, 21 oral papers containing 16 invited papers and 14 poster papers from China, India, Korea, Taiwan, and Japan were presented during the three-day symposium. As a result of the review of poster and oral presentations of young scientists by symposium chairs, Dr Kummetha Raghunatha Reddy (Toyota Technological Institute) received the IUMRS-ICA 2008 Young Researcher Award. We are grateful to all invited speakers and many participants for valuable contributions and active discussions. Organizing committee of Symposium (IUMRS-ICA 2008) Professor Toshiji Kanaya (Kyoto University) Professor Kohji

  11. Linac-driven spallation-neutron source

    SciTech Connect

    Jason, A.J.

    1995-05-01

    Strong interest has arisen in accelerator-driven spallation-neutron sources that surpass existing facilities (such as ISIS at Rutherford or LANSCE at Los Alamos) by more than an order of magnitude in beam power delivered to the spallation target. The approach chosen by Los Alamos (as well as the European Spallation Source) provides the full beam energy by acceleration in a linac as opposed to primary acceleration in a synchrotron or other circular device. Two modes of neutron production are visualized for the source. A short-pulse mode produces 1 MW of beam power (at 60 pps) in pulses, of length less than 1 ms, by compression of the linac macropulse through multi-turn injection in an accumulator ring. A long-pulse mode produces a similar beam power with 1-ms-long pulses directly applied to a target. This latter mode rivals the performance of existing reactor facilities to very low neutron energies. Combination with the short-pulse mode addresses virtually all applications.

  12. Building Science and Technology Solutions for National Problems

    SciTech Connect

    Bishop, Alan R.

    2012-06-05

    The nation's investment in Los Alamos has fostered scientific capabilities for national security missions. As the premier national security science laboratory, Los Alamos tackles: (1) Multidisciplinary science, technology, and engineering challenges; (2) Problems demanding unique experimental and computational facilities; and (3) Highly complex national security issues requiring fundamental breakthroughs. Our mission as a DOE national security science laboratory is to develop and apply science, technology, and engineering solutions that: (1) ensure the safety, security, and reliability of the US nuclear deterrent; (2) protect against the nuclear threat; and (3) solve national security challenges.

  13. MAGNETIC NEUTRON SCATTERING

    SciTech Connect

    ZALIZNYAK,I.A.; LEE,S.H.

    2004-07-30

    Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science

  14. Beam funneling studies at Los Alamos

    SciTech Connect

    Stovall, J.E.; Guy, F.W.; Stokes, R.H.; Wangler, T.P.

    1988-01-01

    Funneling two ion beams by interlacing their bunches can reduce the cost and complexity of systems producing intense beams. Applications of funneling could include accelerators for heavy ion inertial fusion, electronuclear breeding, and fusion materials irradiation. Funneling in an RFQ-like structure is an elegant solution at low energy where electric fields are needed to provide strong focusing. Discrete-element funnels, with separate focusing elements, bending magnets, rebunchers and if deflectors, are more flexible. At sufficiently high energies, magnetic-quadrupole lenses can provide strong focusing in a discrete-element funnel. Such a funnel has been designed as a preliminary example of a second funnel in the HIBALL-II accelerator system. In a simulation, two Bi/sup +1/ (mass = 209 amu) beams at 0.5 MeV/A, 20 MHz, 40-mA, separated by 55 cm and angled at +-6/degree/ were combined into a single 80-mA beam at 40 MHz. Emittance growth was calculated, by a modified version of the PIC (particle-in-cell) code PARMILA, to be about 1%. Funnel design experience at Los Alamos has evolved rules-of-thumb that reduce emittance growth. Some of these are to maintain focusing periodicity and strength in both transverse and longitudinal directions; use strong focusing so that the bunch will be small; minimize angles of bend and rf deflection; adjust longitudinal focusing to produce a short bunch at the rf deflector; and design rf deflectors for a uniform electrical field. 4 refs., 3 figs., 2 tabs.

  15. Materials Capability Review Los Alamos National Laboratory May 4-7, 2009

    SciTech Connect

    Taylor, Antoniette J

    2009-01-01

    Los Alamos National Laboratory (LANL) uses external peer review to measure and continuously improve the quality of its science, technology and engineering (STE). LANL uses capability reviews to assess the STE quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. STE capabilities are define to cut across directorates providing a more holistic view of the STE quality, integration to achieve mission requirements, and mission relevance. The scope of these capabilities necessitate that there will be significant overlap in technical areas covered by capability reviews (e.g ., materials research and weapons science and engineering). In addition, LANL staff may be reviewed in different capability reviews because of their varied assignments and expertise. LANL plans to perform a complete review of the Laboratory's STE capabilities (hence staff) in a three-year cycle. The principal product of an external review is a report that includes the review committee's assessments, commendations, and recommendations for STE. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). This report will be used by Laboratory Management for STE assessment and planning. The report is also provided to the Department of Energy (DOE) as part of LANL's Annual Performance Plan and to the Los Alamos National Security (LANS) LLC's Science and Technology Committee (STC) as part of its responsibilities to the LANS Board of Governors. LANL has defined fourteen STE capabilities. Table 1

  16. Micromegas neutron beam monitor neutronics.

    PubMed

    Stephan, Andrew C; Miller, Laurence F

    2005-01-01

    The Micromegas is a type of ionising radiation detector that consists of a gas chamber sandwiched between two parallel plate electrodes, with the gas chamber divided by a Frisch grid into drift and amplification gaps. Investigators have applied it to a number of different applications, such as charged particle, X-ray and neutron detection. A Micromegas device has been tested as a neutron beam monitor at CERN and is expected to be used for that purpose at the Spallation Neutron Source (SNS) under construction in Oak Ridge, TN. For the Micromegas to function effectively as neutron beam monitor, it should cause minimal disruption to the neutron beam in question. Specifically, it should scatter as few neutrons as possible and avoid neutron absorption when it does not contribute to generating useful information concerning the neutron beam. Here, we present the results of Monte Carlo calculations of the effect of different types of wall materials and detector gases on neutron beams and suggest methods for minimising disruption to the beam. PMID:16381746

  17. Modeling of water radiolysis at spallation neutron sources

    SciTech Connect

    Daemen, L.L.; Kanner, G.S.; Lillard, R.S.; Butt, D.P.; Brun, T.O.; Sommer, W.F.

    1998-12-01

    In spallation neutron sources neutrons are produced when a beam of high-energy particles (e.g., 1 GeV protons) collides with a (water-cooled) heavy metal target such as tungsten. The resulting spallation reactions produce a complex radiation environment (which differs from typical conditions at fission and fusion reactors) leading to the radiolysis of water molecules. Most water radiolysis products are short-lived but extremely reactive. When formed in the vicinity of the target surface they can react with metal atoms, thereby contributing to target corrosion. The authors will describe the results of calculations and experiments performed at Los Alamos to determine the impact on target corrosion of water radiolysis in the spallation radiation environment. The computational methodology relies on the use of the Los Alamos radiation transport code, LAHET, to determine the radiation environment, and the AEA code, FACSIMILE, to model reaction-diffusion processes.

  18. Isomeric ratio measurements for the radiative neutron capture 176Lu(n,γ) at DANCE

    NASA Astrophysics Data System (ADS)

    Denis-Petit, D.; Roig, O.; Méot, V.; Jandel, M.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.

    2016-03-01

    The isomeric ratio for the neutron capture reaction 176Lu(n,γ) on the Jπ= 5/2-, 761.7 keV, T1/2=32.8 ns level of 177mLu, has been determined in the neutron energy range 8.5 eV-100 keV for the first time using the DANCE array at the Los Alamos National Laboratory.

  19. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  20. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  1. Characterization of emergent leakage neutrons from multiple layers of hydrogen/water in the lunar regolith by Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    SU, J.; Sagdeev, R.; Usikov, D.; Chin, G.; Boyer, L.; Livengood, T. A.; McClanahan, T. P.; Murray, J.; Starr, R. D.

    2013-12-01

    CSETN from the leakage neutron spectrum, emission angle, detector energy sensitivity and angular response. Reference: [1] W. C. Feldman, et al., Science 4 September 1998: Vol. 281 no. 5382 pp. 1496-1500. [2] Gasnault, O., et al., (2000) J. Geophys. Res., 105(E2), 4263-4271. [3] Little, R. C., et al. (2003), J. Geophys. Res., 108(E5), 5046. [4] McKinney et al., (2006), J. Geophys. Res., 111, E06004. [5] Lawrence et al., (2006), J. Geophys. Res., 111, E08001. [6] Looper et al, (2013), Space Weather, VOL. 11, 142-152. [7] J. Allison, et al, (2006) IEEE TRANS. ON NUCL SCI, VOL. 53, NO. 1. [8] J. Masarik and R. Reedy (1996), J. Geophys. Res., 101, 18,891-18,912. [9] P. O'Neil (2010) IEEE Trans. Nucl. Sci., 57(6), 3148-3153. [10] D. Pelowitz, (2005), Rep. LA-CP-05-0369, LANL, Los Alamos, NM.

  2. American Conference on Neutron Scattering 2014

    SciTech Connect

    Dillen, J. Ardie

    2014-12-31

    Scientists from the around the world converged in Knoxville, TN to have share ideas, present technical information and contribute to the advancement of neutron scattering. Featuring over 400 oral/poster presentations, ACNS 2014 offered a strong program of plenary, invited and contributed talks and poster sessions covering topics in soft condensed matter, hard condensed matter, biology, chemistry, energy and engineering applications in neutron physics – confirming the great diversity of science that is enabled by neutron scattering.

  3. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  4. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  5. Neutrons for biologists: a beginner's guide, or why you should consider using neutrons.

    PubMed

    Lakey, Jeremy H

    2009-10-01

    From the structures of isolated protein complexes to the molecular dynamics of whole cells, neutron methods can achieve a resolution in complex systems that is inaccessible to other techniques. Biology is fortunate in that it is rich in water and hydrogen, and this allows us to exploit the differential sensitivity of neutrons to this element and its major isotope, deuterium. Furthermore, neutrons exhibit wave properties that allow us to use them in similar ways to light, X-rays and electrons. This review aims to explain the basics of biological neutron science to encourage its greater use in solving difficult problems in the life sciences. PMID:19656821

  6. Amorphous Silicon Based Neutron Detector

    SciTech Connect

    Xu, Liwei

    2004-12-12

    Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield using low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: · High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; · Various single-junction and double junction detector devices have been fabricated; · The detector devices fabricated have been systematically tested and analyzed. · Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies

  7. Prompt fission neutron spectra of actinides

    DOE PAGESBeta

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; Kornilov, N. V.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; et al

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  8. 1993 Northern goshawk inventory on portions of Los Alamos National Laboratory, Los Alamos, NM. Final report

    SciTech Connect

    Sinton, D.T.; Kennedy, P.L.

    1994-06-01

    Northern goshawks (Accipiter gentilis) (hereafter referred to as goshawk) is a large forest dwelling hawk. Goshawks may be declining in population and reproduction in the southwestern United States. Reasons for the possible decline in goshawk populations include timber harvesting resulting in the loss of nesting habitat, toxic chemicals, and the effects of drought, fire, and disease. Thus, there is a need to determine their population status and assess impacts of management activities in potential goshawk habitat. Inventory for the goshawk was conducted on 2,254 ha of Los Alamos National Laboratory (LANL) to determine the presence of nesting goshawks on LANL lands. This information can be incorporated into LANL`s environmental management program. The inventory was conducted by Colorado State University personnel from May 12 to July 30, 1993. This report summarizes the results of this inventory.

  9. Upgrades to the Polarized Neutron Reflectometer Asterix at LANSCE

    SciTech Connect

    Pynn, Roger

    2015-03-16

    We have upgraded the polarized neutron reflectometer, Asterix, at the Lujan Neutron Scattering Center at Los Alamos for the benefit of the research communities that study magnetic and complex-fluid films, both of which play important roles in support of the DOE’s energy mission. The upgrades to the instrument include: • A secondary spectrometer that was integrated with a Huber sample goniometer purchased with other funds just prior to the start of our project. The secondary spectrometer provides a flexible length for the scattered flight path, includes a mechanism to select among 3 alternative polarization analyzers as well as a support for new neutron detectors. Also included is an optic rail for reproducible positioning of components for Spin Echo Scattering Angle Measurement (SESAME). The entire secondary spectrometer is now non-magnetic, as required for neutron Larmor labeling. • A broad-band neutron polarizer for the incident neutron beam based on the V geometry. • A wide-angle neutron polarization analyzer • A 2d position-sensitive neutron detector • Electromagnetic coils (Wollaston prisms) for SESAME plus the associated power supplies, cooling, safety systems and integration into the data acquisition system. The upgrades allowed a nearly effortless transition between configurations required to serve the polarized neutron reflectometry community, users of the 11 T cryomagnet and users of SESAME.

  10. Publications of Los Alamos research, 1977-1981

    SciTech Connect

    Sheridan, C.J.; Garcia, C.A.

    1983-03-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  11. Water Supply at Los Alamos 1998-2001

    SciTech Connect

    Richard J. Koch; David B. Rogers

    2003-03-01

    For the period 1998 through 2001, the total water used at Los Alamos from all sources ranged from 1325 million gallons (Mg) in 1999 to 1515 Mg in 2000. Groundwater production ranged from 1323 Mg in 1999 to 1506 Mg in 2000 from the Guaje, Pajarito, and Otowi fields. Nonpotable surface water used from Los Alamos reservoir ranged from zero gallons in 2001 to 9.3 Mg in 2000. For years 1998 through 2001, over 99% of all water used at Los Alamos was groundwater. Water use by Los Alamos National Laboratory (LANL) between 1998 and 2001 ranged from 379 Mg in 2000 to 461 Mg in 1998. The LANL water use in 2001 was 393 Mg or 27% of the total water use at Los Alamos. Water use by Los Alamos County ranged from 872 Mg in 1999 to 1137 Mg in 2000, and averaged 1006 Mg/yr. Four new replacement wells in the Guaje field (G-2A, G-3A, G-4A, and G-5A) were drilled in 1998 and began production in 1999; with existing well G-1A, the Guaje field currently has five producing wells. Five of the old Guaje wells (G-1, G-2, G-4, G-5, and G-6) were plugged and abandoned in 1999, and one well (G-3) was abandoned but remains as an observation well for the Guaje field. The long-term water level observations in production and observation (test) wells at Los Alamos are consistent with the formation of a cone of depression in response to water production. The water level decline is gradual and at most has been about 0.7 to 2 ft per year for production wells and from 0.4 to 0.9 ft/yr for observation (test) wells. The largest water level declines have been in the Guaje field where nonpumping water levels were about 91 ft lower in 2001 than in 1951. The initial water levels of the Guaje replacement wells were 32 to 57 ft lower than the initial water levels of adjacent original Guaje wells. When production wells are taken off-line for pump replacement or repair, water levels have returned to within about 25 ft of initial static levels within 6 to 12 months. Thus, the water-level trends suggest no adverse

  12. A progress report on UNICOS misuse detection at Los Alamos

    SciTech Connect

    Thompson, J.L.; Jackson, K.A.; Stallings, C.A.; Simmonds, D.D.; Siciliano, C.L.B.; Pedicini, G.A.

    1995-10-01

    An effective method for detecting computer misuse is the automatic monitoring and analysis of on-line user activity. During the past year, Los Alamos enhanced its Network Anomaly Detection and Intrusion Reporter (NADIR) to include analysis of user activity on Los Alamos` UNICOS Crays. In near real-time, NADIR compares user activity to historical profiles and tests activity against expert rules. The expert rules express Los Alamos` security policy and define improper or suspicious behavior. NADIR reports suspicious behavior to security auditors and provides tools to aid in follow-up investigations. This paper describes the implementation to date of the UNICOS component of NADIR, along with the operational experiences and future plans for the system.

  13. Experimental Physical Sciences Vistas: MaRIE (draft)

    SciTech Connect

    Shlachter, Jack

    2010-09-08

    science challenges. Our first issue of Vistas focused on our current national user facilities (the Los Alamos Neutron Science Center [LANSCE], the National High Magnetic Field Laboratory-Pulsed Field Facility, and the Center for Integrated Nanotechnologies) and the vitality they bring to our Laboratory. These facilities are a magnet for students, postdoctoral researchers, and staff members from all over the world. This, in turn, allows us to continue to develop and maintain our strong staff across the relevant disciplines and conduct world-class discovery science. The second issue of Vistas was devoted entirely to the Laboratory's materials strategy - one of the three strategic science thrusts for the Laboratory. This strategy has helped focus our thinking for MaRIE. We believe there is a bright future in cutting-edge experimental materials research, and that a 21st-century facility with unique capability is necessary to fulfill this goal. The Laboratory has spent the last several years defining MaRIE, and this issue of Vistas presents our current vision of that facility. MaRIE will leverage LANSCE and our other user facilities, as well as our internal and external materials community for decades to come, giving Los Alamos a unique competitive advantage, advancing materials science for the Laboratory's missions and attracting and recruiting scientists of international stature. MaRIE will give the international materials research community a suite of tools capable of meeting a broad range of outstanding grand challenges.

  14. NEUTRON SOURCE

    DOEpatents

    Bernander, N.K. et al.

    1960-10-18

    An apparatus is described for producing neutrons through target bombardment with deuterons. Deuterium gas is ionized by electron bombardment and the deuteron ions are accelerated through a magnetic field to collimate them into a continuous high intensity beam. The ion beam is directed against a deuteron pervious metal target of substantially the same nnaterial throughout to embed the deuterous therein and react them to produce neutrons. A large quantity of neutrons is produced in this manner due to the increased energy and quantity of ions bombarding the target.

  15. Modulating the Neutron Flux from a Mirror Neutron Source

    SciTech Connect

    Ryutov, D D

    2011-09-01

    A 14-MeV neutron source based on a Gas-Dynamic Trap will provide a high flux of 14 MeV neutrons for fusion materials and sub-component testing. In addition to its main goal, the source has potential applications in condensed matter physics and biophysics. In this report, the author considers adding one more capability to the GDT-based neutron source, the modulation of the neutron flux with a desired frequency. The modulation may be an enabling tool for the assessment of the role of non-steady-state effects in fusion devices as well as for high-precision, low-signal basic science experiments favoring the use of the synchronous detection technique. A conclusion is drawn that modulation frequency of up to 1 kHz and modulation amplitude of a few percent is achievable. Limitations on the amplitude of modulations at higher frequencies are discussed.

  16. The development of the atomic bomb, Los Alamos

    SciTech Connect

    Seidel, R.W.

    1993-11-01

    The historical presentation begins with details of the selection of Los Alamos as the site of the Army installation. Wartime efforts of the Army Corps of Engineers, and scientists to include the leader of Los Alamos, Robert Oppenheimer are presented. The layout and construction of the facilities are discussed. The monumental design requirements of the bombs are discussed, including but not limited to the utilization of the second choice implosion method of detonation, and the production of bomb-grade nuclear explosives. The paper ends with a philosophical discussion on the use of nuclear weapons.

  17. Fifty-one years of Los Alamos Spacecraft

    SciTech Connect

    Fenimore, Edward E.

    2014-09-04

    From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

  18. Thermal neutron detection system

    DOEpatents

    Peurrung, Anthony J.; Stromswold, David C.

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  19. (n,2n) and (n,3n) cross sections of neutron-induced reactions on 150Sm for En from threshold to 35 MeV

    SciTech Connect

    Dashdorj, D; Mitchell, G; Kawano, T; Becker, J; Wu, C; Devlin, M; Fotiades, N; Nelson, R; Kunieda, S

    2009-03-16

    Cross-section measurements were made of prompt discrete {gamma}-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on a {sup 150}Sm sample fo 1550 mg/cm{sup 2} of Sm{sub 2}O{sub 3} enriched to 95.6% in {sup 150}Sm. Results are compared with enhanced Hauser-Feshbach model calculations including the pre-equilibrium reactions. Energetic neutrons were delivered by the Los Alamos Neutron Science Center facility. The prompt-reaction {gamma} rays were detected with the Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Incident neutron energies were determined by the time-of-flight technique. Excitation functions for thirteen individual {gamma}-rays up to E{sub x} = 0.8 MeV in {sup 149}Sm and one {gamma}-ray transition between the first excited and ground state in {sup 148}Sm were measured. Partial {gamma}-ray cross sections were calculated using GNASH, an enhanced Hauser-Feshbach statistical nuclear reaction model code, and compared with the experimental results. The particle transmission coefficients were calculated with new systematic 'global' optical model potential parameters. The coupled-channel optical model based on the soft rotor model was employed to calculate the particle transmission coefficients. The pre-equilibrium part of the spin distribution in {sup 150}Sm was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK) and incorporated into the GNASH reaction model code. the partial cross sections for discrete {gamma}-ray cascade paths leading to the ground state in {sup 149}Sm and {sup 148}Sm have been summed (without double counting) to estimate lower limits for reaction cross sections. These lower limits are combined with Hauser-Feshbach model calculations to deduce the reaction channel cross sections. These reaction channel cross sections agree with previously measured experimental and ENDF/B-VII evaluations.

  20. Improved Determination of the Neutron Lifetime

    NASA Astrophysics Data System (ADS)

    Yue, A.

    2013-10-01

    The most precise determination of the neutron lifetime using the beam method reported a result of τn = (886 . 3 +/- 3 . 4) s. The dominant uncertainties were attributed to the absolute determination of the fluence of the neutron beam (2.7 s). The fluence was determined with a monitor that counted the neutron-induced charged particles from absorption in a thin, well-characterized 6Li deposit. The detection efficiency of the monitor was calculated from the areal density of the deposit, the detector solid angle, and the ENDF/B-VI 6Li(n,t)4He thermal neutron cross section. We have used a second, totally-absorbing neutron detector to directly measure the detection efficiency of the monitor on a monochromatic neutron beam of precisely known wavelength. This method does not rely on the 6Li(n,t)4He cross section or any other nuclear data. The monitor detection efficiency was measured to an uncertainty of 0.06%, which represents a five-fold improvement in uncertainty. We have verified the temporal stability of the monitor with ancillary measurements, and the measured neutron monitor efficiency has been used to improve the fluence determination in the past lifetime experiment. An updated neutron lifetime based on the improved fluence determination will be presented. Work done in collaboration with M. Dewey, D. Gilliam, J. Nico, National Institute of Standards and Technology; G. Greene, University of Tennessee / Oak Ridge National Laboratory; A. Laptev, Los Alamos National Laboratory; W. Snow, Indiana University; and F. Wietfeldt, Tulane University.

  1. JCANS network of compact neutron facilities in Japan

    NASA Astrophysics Data System (ADS)

    Kiyanagi, Yoshiaki

    2016-05-01

    Compact neutron sources are used to promote neutron science as they can be used for studies relevant to the own interests of a researcher, and they are most suitable for educational purposes, trial use by beginners, test experiments, and challenging measurements. This type of activities supports researches at a large facility. Japan collaboration of accelerator-driven neutron sources (JCANS), which is a network of accelerator-driven neutron sources, is organized to activate a nation-wide network of individual research activities on neutron sources and practical neutron beam technologies for application in science and industry. This network promotes a collaborative work to construct neutron sources and use them in science and industry fields.

  2. Needs assessment for fire department services and resources for the Los Alamos National Laboratory, Los Alamos, New Mexico. Final report

    SciTech Connect

    1995-11-15

    This report has been developed in response to a request from the Los Alamos National Laboratory (LANL) to evaluate the need for fire department services so as to enable the Laboratory to plan effective fire protection and thereby: meet LANL`s regulatory and contractual obligations; interface with the Department of Energy (DOE) and other agencies on matters relating to fire and emergency services; and ensure appropriate protection of the community and environment. This study is an outgrowth of the 1993 Fire Department Needs Assessment (prepared for DOE) but is developed from the LANL perspective. Input has been received from cognizant and responsible representatives at LANL, DOE, Los Alamos County (LAC) and the Los Alamos Fire Department (LAFD).

  3. NEUTRONIC REACTOR

    DOEpatents

    Wade, E.J.

    1958-09-16

    This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

  4. Analysis and simulation of a small-angle neutron scattering instrument on a 1 MW long pulse spallation source

    SciTech Connect

    Olah, G.A.; Hjelm, R.P.; Lujan, M. Jr.

    1996-12-31

    We studied the design and performance of a small-angle neutron scattering (SANS) instrument for a proposed 1 MW, 60 Hz long pulsed spallation source at the Los Alamos Neutron Science Center (LANSCE). An analysis of the effects of source characteristics and chopper performance combined with instrument simulations using the LANSCE Monte Carlo instrument simulations package shows that the T{sub 0} chopper should be no more than 5 m from the source with the frame overlap and frame definition choppers at 5.6 and greater than 7 m, respectively. The study showed that an optimal pulse structure has an exponential decaying tail with {tau} {approx} 750 {mu}s. The Monte Carlo simulations were used to optimize the LPSS SANS, showing that an optimal length is 18 m. The simulations show that an instrument with variable length is best to match the needs of a given measurement. The performance of the optimized LPSS instrument was found to be comparable with present world standard instruments.

  5. NEUTRONIC REACTOR

    DOEpatents

    Fraas, A.P.; Mills, C.B.

    1961-11-21

    A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

  6. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  7. Neutron range spectrometer

    DOEpatents

    Manglos, S.H.

    1988-03-10

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

  8. Gravitational Waves from Neutron Stars

    NASA Astrophysics Data System (ADS)

    Kokkotas, Konstantinos

    2016-03-01

    Neutron stars are the densest objects in the present Universe, attaining physical conditions of matter that cannot be replicated on Earth. These unique and irreproducible laboratories allow us to study physics in some of its most extreme regimes. More importantly, however, neutron stars allow us to formulate a number of fundamental questions that explore, in an intricate manner, the boundaries of our understanding of physics and of the Universe. The multifaceted nature of neutron stars involves a delicate interplay among astrophysics, gravitational physics, and nuclear physics. The research in the physics and astrophysics of neutron stars is expected to flourish and thrive in the next decade. The imminent direct detection of gravitational waves will turn gravitational physics into an observational science, and will provide us with a unique opportunity to make major breakthroughs in gravitational physics, in particle and high-energy astrophysics. These waves, which represent a basic prediction of Einstein's theory of general relativity but have yet to be detected directly, are produced in copious amounts, for instance, by tight binary neutron star and black hole systems, supernovae explosions, non-axisymmetric or unstable spinning neutron stars. The focus of the talk will be on the neutron star instabilities induced by rotation and the magnetic field. The conditions for the onset of these instabilities and their efficiency in gravitational waves will be presented. Finally, the dependence of the results and their impact on astrophysics and especially nuclear physics will be discussed.

  9. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  10. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  11. A survey of macromycete diversity at Los Alamos National Laboratory, Bandelier National Monument, and Los Alamos County; A preliminary report

    SciTech Connect

    Jarmie, N.; Rogers, F.J.

    1997-11-01

    The authors have completed a 5-year survey (1991--1995) of macromycetes found in Los Alamos County, Los Alamos National Laboratory, and Bandelier National Monument. The authors have compiled a database of 1,048 collections, their characteristics, and identifications. The database represents 123 (98%) genera and 175 (73%) species reliably identified. Issues of habitat loss, species extinction, and ecological relationships are addressed, and comparisons with other surveys are made. With this baseline information and modeling of this baseline data, one can begin to understand more about the fungal flora of the area.

  12. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  13. Installation of a cw radiofrequency quadrupole accelerator at Los Alamos National Laboratory

    SciTech Connect

    Schneider, J.D.; Bolme, J.; Brown, V.

    1994-09-01

    Chalk River Laboratories (CRL) has had a long history of cw proton beam development for production of intense neutron sources and fissile fuel breeders. In 1986 CRL and Los Alamos National Laboratory (LANL) entered into a collaborative effort to establish a base technologies program for the development of a cw radiofrequency quadrupole (RFQ). The initial cw RFQ design had 50-keV proton injection energy with 600-keV output energy. The 75-mA design current at 600-keV beam energy was obtained in 1990. Subsequently, the RFQ output energy was increased to 1250 keV by replacing the RFQ vanes, still maintaining the 75-m A design current. A new 250-kW cw klystrode rf power source at 267-MHz was installed at CRL. By April of 1993, 55-mA proton beams had been accelerated to 1250 keV. Concurrent developments were taking place on proton source development and on 50-keV low-energy beam transport (LEBT) systems. Development of a dc, high-proton fraction ({ge} 70%) microwave ion source led to utilization of a single-solenoid RFQ direct injection scheme. It was decided to continue this cw RFQ demonstration project at Los Alamos when the CRL project was terminated in April 1993. The LANL goals are to find the current limit of the 1250-keV RFQ, better understand the beam transport properties through the single-solenoid focusing LEBT, continue the application of the cw klystrode tube technology to accelerators, and develop a two-solenoid LEBT which could be the front end of an Accelerator-Driven Transmutation Technologies (ADTT) linear accelerator.

  14. Nuclear criticality safety staff training and qualifications at Los Alamos National Laboratory

    SciTech Connect

    Monahan, S.P.; McLaughlin, T.P.

    1997-05-01

    Operations involving significant quantities of fissile material have been conducted at Los Alamos National Laboratory continuously since 1943. Until the advent of the Laboratory`s Nuclear Criticality Safety Committee (NCSC) in 1957, line management had sole responsibility for controlling criticality risks. From 1957 until 1961, the NCSC was the Laboratory body which promulgated policy guidance as well as some technical guidance for specific operations. In 1961 the Laboratory created the position of Nuclear Criticality Safety Office (in addition to the NCSC). In 1980, Laboratory management moved the Criticality Safety Officer (and one other LACEF staff member who, by that time, was also working nearly full-time on criticality safety issues) into the Health Division office. Later that same year the Criticality Safety Group, H-6 (at that time) was created within H-Division, and staffed by these two individuals. The training and education of these individuals in the art of criticality safety was almost entirely self-regulated, depending heavily on technical interactions between each other, as well as NCSC, LACEF, operations, other facility, and broader criticality safety community personnel. Although the Los Alamos criticality safety group has grown both in size and formality of operations since 1980, the basic philosophy that a criticality specialist must be developed through mentoring and self motivation remains the same. Formally, this philosophy has been captured in an internal policy, document ``Conduct of Business in the Nuclear Criticality Safety Group.`` There are no short cuts or substitutes in the development of a criticality safety specialist. A person must have a self-motivated personality, excellent communications skills, a thorough understanding of the principals of neutron physics, a safety-conscious and helpful attitude, a good perspective of real risk, as well as a detailed understanding of process operations and credible upsets.

  15. Science in 60 – The Hunt for Antarctic Meteorites

    SciTech Connect

    Lanza, Nina

    2015-12-08

    She's the "coolest" thing in science, searching the ice sheets of Antarctica for meteorites from outer space. Los Alamos National Laboratory scientist Nina Lanza has signed up to spend nearly six weeks in a tent on the Antarctic ice sheet. Why would anyone do such a thing? For science, obviously! In the premiere episode of Los Alamos National Laboratory's "Science in 60" video series, Lanza gives us the low-down in 60 seconds on the why and how of hunting meteorites on the ice.

  16. Airport-Noise Levels and Annoyance Model (ALAMO) system's reference manual

    NASA Technical Reports Server (NTRS)

    Deloach, R.; Donaldson, J. L.; Johnson, M. J.

    1986-01-01

    The airport-noise levels and annoyance model (ALAMO) is described in terms of the constituent modules, the execution of ALAMO procedure files, necessary for system execution, and the source code documentation associated with code development at Langley Research Center. The modules constituting ALAMO are presented both in flow graph form, and through a description of the subroutines and functions that comprise them.

  17. Inertial confinement fusion at the Los Alamos National Laboratory

    SciTech Connect

    Lindman, E.; Baker, D.; Barnes, C.; Bauer, B.; Beck, J.B.

    1997-11-01

    The Los Alamos National Laboratory is contributing to the resolution of key issues in the US Inertial-Confinement-Fusion Program and plans to play a strong role in the experimental program at the National Ignition Facility when it is completed.

  18. Direct-current proton-beam measurements at Los Alamos

    SciTech Connect

    Sherman, Joseph; Stevens, Ralph R.; Schneider, J. David; Zaugg, Thomas

    1995-09-15

    Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H2 gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos will be given.

  19. Direct-current proton-beam measurements at Los Alamos

    SciTech Connect

    Sherman, J.; Stevens, R.R.; Schneider, J.D.; Zaugg, T.

    1994-08-01

    Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H{sub 2} gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos is given.

  20. High-energy density physics at Los Alamos

    NASA Astrophysics Data System (ADS)

    Byrnes, P.

    1993-03-01

    This brochure describes the facilities of the Above Ground Experiments 2 (AGEX 2) and the Inertial Confinement Fusion (ICF) programs at Los Alamo. Combined, these programs represent, an unparalleled capability to address important issues in high-energy density physics that are critical to the future defense, energy, and research needs of the United States. The mission of the AGEX 2 program at Los Alamos is to provide additional experimental opportunities for the nuclear weapons program. For this purpose we have assembled at Los Alamos the broadest array of high-energy density physics facilities of any laboratory in the world. Inertial confinement fusion seeks to achieve thermonuclear burn on a laboratory scale through the implosion of a small quantity of deuterium and tritium fuel to very high pressure and temperature. The Los Alamos ICF program is focused on target physics. With the largest scientific computing center in the world, We can perform calculations of unprecedented sophistication and precision. We field experiments at facilities worldwide--including our own Trident and Mercury lasers--to confirm our understanding and to provide the necessary data base to proceed toward the historic goal of controlled fusion in the laboratory. The ultrahigh magnetic fields produced in our high explosive pulsed-power generators can be used in a wide variety of solid state physics and temperature superconductor studies. The structure and dynamics of planetary atmospheres can be simulated through the compression of gas mixtures.

  1. The Los Alamos nuclear safeguards and nonproliferation technology development program

    SciTech Connect

    Smith, H.A. Jr.; Menlove, H.O.; Reilly, T.D.; Bosler, G.E.; Hakkila, E.A.; Eccleston, G.W.

    1994-04-01

    For nearly three decades, Los Alamos National Laboratory has developed and implemented nuclear measurement technology and training in support of national and international nuclear safeguards. This paper outlines the major elements of those technologies and highlights some of the latest developments.

  2. Working with Fermi at Chicago and Los Alamos

    NASA Astrophysics Data System (ADS)

    Garwin, Richard L.

    2010-02-01

    I discuss my experience with Enrico Fermi as student and fellow faculty member at Chicago and with him as consultants to the Los Alamos Scientific Laboratory in 1950-1952. The talk shares observations about this great physicist and exemplary human being. )

  3. Optical velocimetry at the Los Alamos Proton Radiography Facility

    NASA Astrophysics Data System (ADS)

    Tupa, Dale; Tainter, Amy; Neukirch, Levi; Hollander, Brian; Buttler, William; Holtkamp, David; The Los Alamos Proton Radiography Team Team

    2016-05-01

    The Los Alamos Proton Radiography Facility (pRad) employs a high-energy proton beam to image the properties and behavior of materials driven by high explosives. We will discuss features of pRad and describe some recent experiments, highlighting optical diagnostics for surface velocity measurements.

  4. The Controlled-Air Incinerator at Los Alamos

    SciTech Connect

    Newmyer, J.N.

    1994-04-01

    The Controlled-Air Incinerator (CAI) at Los Alamos is being modified and upgraded to begin routine operations treating low-level mixed waste (LLMW), radioactively contaminated polychlorinated biphenyl (PCB) wastes, low-level liquid wastes, and possibly transuranic (TRU) wastes. This paper describes those modifications. Routine waste operations should begin in late FY95.

  5. [Los Alamos National Laboratory industrial applications and technology transfer

    SciTech Connect

    Not Available

    1992-09-30

    In October 1989, the Los Alamos Economic Development Corporation (LAEDC) entered into a contract with the Industrial Applications office (IAO) of Los Alamos National Laboratory (LANL) whereby the LAEDC was to provide support services to IAO. More specifically, according to the Statement of Work in this contract The Los Alamos Economic Development Corporation shall assist the Los Alamos National Laboratory Industrial Applications Office in establishing and strengthening connections between potential entrepreneurs at the Laboratory and the business assistance community throughout New Mexico, directed toward enhancing the number, of successful start up businesses spinning off the Laboratory's technology base.'' As part of this contract and subsequent modifications thereof, the LAEDC was to perform seven tasks: 1. Provide business planning assistance to potential entrepreneurs. 2. (Assist IAO in preparing and distributing) informational materials on technology transfer. 3. (Organize and manage) meetings and seminars on technology transfer and entrepreneurship. 4. Identify new opportunities for technology transfer. 5. (Identify and implement programs for the) recognition of Laboratory Entrepreneurs. 6. Training Lab personnel, in the area of technology transfer and Laboratory industrial interactions. 7. Review and summarize prior New Mexico economic development studies. The purpose of this report, is to summarize the accomplishments of the LAEDC under its contract with IAO, and to fulfill its reporting requirements. This report covers the period from October 1989 to September 1992.

  6. Brief review of Rover fuel development at Los Alamos

    NASA Technical Reports Server (NTRS)

    Davidson, Keith V.

    1991-01-01

    A brief review of the graphite matrix uranium fuel development efforts at Los Alamos from 1955 through 1972 is presented. The uses of graphite flour carbon black, various binders, uranium dioxide, coated UC2 particles, and zirconium carbide in this development are described.

  7. Thermal Cycling Absorption Process (TCAP): Instrument and Simulation Development Status at Los Alamos National Laboratory

    SciTech Connect

    Arias, Angela A.; Schmierer, Eric N.; Gettemy, Donald; Howard, David W.; Wermer, Joseph R.; Tuggle, Dale G.

    2005-07-15

    The Thermal Cycling Absorption Process (TCAP) Project at Los Alamos National Laboratory has been a collaborative effort with Savannah River Site to demonstrate the Tube-in-Tube (TnT) column design and to improve TCAP science. TnT TCAP is an alternative design which uses a liquid to thermally cycle the metal hydride packed column. Inert gas displacement tests and deuterium pulse tests have been performed on the TnT TCAP column. The inert gas displacement tests are designed to measure plug flow in the column while the deuterium pulse tests determine the separation ability of the column. A residual gas analyzer measures the gases in the exit stream and the experimental results are compared with pulse test model results.

  8. High-energy neutron dosimetry at the Clinton P. Anderson Meson Physics Facility

    SciTech Connect

    Mallett, M.W.; Vasilik, D.G.; Littlejohn, G.J.; Cortez, J.R.

    1990-01-01

    Neutron energy spectrum measurements performed at the Clinton P. Anderson Meson Physics Facility indicated potential areas for high energy neutron exposure to personnel. The low sensitivity of the Los Alamos thermoluminescent dosimeter (TLD) to high energy neutrons warranted issuing a NTA dosimeter in addition to the TLD badge to employees entering these areas. The dosimeter consists of a plastic holder surrounding NTA film that has been desiccated and sealed in a dry nitrogen environment. A study of the fading of latent images in NTA film demonstrated the success of this packaging method to control the phenomenon. The Los Alamos NTA dosimeter is characterized and the fading study discussed. 10 refs., 4 figs., 2 tabs.

  9. Neutron streaming through shield ducts using a discrete ordinates/Monte Carlo method

    SciTech Connect

    Urban, W.T.; Baker, R.S.

    1993-08-18

    A common problem in shield design is determining the neutron flux that streams through ducts in shields and also that penetrates the shield after having traveled partway down the duct. Obviously the determination of the neutrons that stream down the duct can be computed in a straightforward manner using Monte Carlo techniques. On the other hand those neutrons that must penetrate a significant portion of the shield are more easily handled using discrete ordinates methods. A hybrid discrete ordinates/Monte Carlo cods, TWODANT/MC, which is an extension of the existing discrete ordinates code TWODANT, has been developed at Los Alamos to allow the efficient, accurate treatment of both streaming and deep penetration problems in a single calculation. In this paper we provide examples of the application of TWODANT/MC to typical geometries that are encountered in shield design and compare the results with those obtained using the Los Alamos Monte Carlo code MCNP{sup 3}.

  10. Environmental Survey preliminary report, Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    Not Available

    1988-01-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy's (DOE) Los Alamos National Laboratory (LANL), conducted March 29, 1987 through April 17, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are outside experts being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the LANL. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at the LANL, and interviews with site personnel. The Survey team developed Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by the Idaho National Engineering Laboratory. When completed, the results will be incorporated into the LANL Environmental Survey Interim Report. The Interim Report will reflect the final determinations of the Survey for the LANL. 65 refs., 68 figs., 73 tabs.

  11. Environmental assessment for effluent reduction, Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    1996-09-11

    The Department of Energy (DOE) proposes to eliminate industrial effluent from 27 outfalls at Los Alamos National Laboratory (LANL). The Proposed Action includes both simple and extensive plumbing modifications, which would result in the elimination of industrial effluent being released to the environment through 27 outfalls. The industrial effluent currently going to about half of the 27 outfalls under consideration would be rerouted to LANL`s sanitary sewer system. Industrial effluent from other outfalls would be eliminated by replacing once-through cooling water systems with recirculation systems, or, in a few instances, operational changes would result in no generation of industrial effluent. After the industrial effluents have been discontinued, the affected outfalls would be removed from the NPDES Permit. The pipes from the source building or structure to the discharge point for the outfalls may be plugged, or excavated and removed. Other outfalls would remain intact and would continue to discharge stormwater. The No Action alternative, which would maintain the status quo for LANL`s outfalls, was also analyzed. An alternative in which industrial effluent would be treated at the source facilities was considered but dismissed from further analysis because it would not reasonably meet the DOE`s purpose for action, and its potential environmental effects were bounded by the analysis of the Proposed Action and the No Action alternatives.

  12. Gravitational Redshift of Deformed Neutron Stars

    NASA Astrophysics Data System (ADS)

    Romero, Alexis; Zubairi, Omair; Weber, Fridolin

    2015-04-01

    Non-rotating neutron stars are generally treated in theoretical studies as perfect spheres. Such a treatment, however, may not be correct if strong magnetic fields are present and/or the pressure of the matter in the cores of neutron stars is non-isotropic, leading to neutron stars which are deformed. In this work, we investigate the impact of deformation on the gravitational redshift of neutron stars in the framework of general relativity. Using a parameterized metric to model non-spherical mass distributions, we derive an expression for the gravitational redshift in terms of the mass, radius, and deformity of a neutron star. Numerical solutions for the redshifts of sequences of deformed neutron stars are presented and observational implications are pointed out. This research is funded by the NIH through the Maximizing Access to Research Careers (MARC), under Grant Number: 5T34GM008303-25 and through the National Science Foundation under grant PHY-1411708.

  13. Commercialization of Los Alamos National Laboratory technologies via small businesses. Final report

    SciTech Connect

    Brice, R.; Carton, D.; Rhyne, T.

    1997-06-01

    Appendices are presented from a study performed on a concept model system for the commercialization of Los Alamos National Laboratory technologies via small businesses. Topics include a summary of information from the joint MCC/Los Alamos technology conference; a comparison of New Mexico infrastructure to other areas; a typical licensing agreement; technology screening guides; summaries of specific DOE/UC/Los Alamos documents; a bibliography; the Oak Ridge National Laboratory TCRD; The Ames Center for Advanced Technology Development; Los Alamos licensing procedures; presentation of slides from monthly MCC/Los Alamos review meetings; generalized entrepreneurship model; and a discussion on receiving equity for technology.

  14. Neutron and gamma-ray measurements on the LANL Little Boy Comet Assembly

    SciTech Connect

    Hankins, D.E.

    1983-09-01

    We measured the neutron and gamma-ray dose rates at various distances from the Little Boy Comet Assembly at Los Alamos National Laboratory (LANL), Los Alamos, New Mexico on April 28 and 29, 1983. The distances selected varied from 350 ft to 1860 ft from the assembly, with the latter point being located at the edge of the mesa overlooking Pajarito Canyon. We varied the power levels for the various runs but we have normalized all of them to a single power-level. We also made corrections for the variations in the power-level indicators of the assembly using data provided by LANL.

  15. SABRINA - An interactive geometry modeler for MCNP (Monte Carlo Neutron Photon)

    SciTech Connect

    West, J.T.; Murphy, J.

    1988-01-01

    SABRINA is an interactive three-dimensional geometry modeler developed to produce complicated models for the Los Alamos Monte Carlo Neutron Photon program MCNP. SABRINA produces line drawings and color-shaded drawings for a wide variety of interactive graphics terminals. It is used as a geometry preprocessor in model development and as a Monte Carlo particle-track postprocessor in the visualization of complicated particle transport problem. SABRINA is written in Fortran 77 and is based on the Los Alamos Common Graphics System, CGS. 5 refs., 2 figs.

  16. FOREWORD: VI Workshop in Electron Volt Neutron Spectroscopy: Frontiers and Horizons

    NASA Astrophysics Data System (ADS)

    Seel, A. G.; Senesi, R.; Fernandez-Alonso, F.

    2014-12-01

    January 2014 saw the congregation in Abingdon (UK) of scientists from across the world, to discuss the current state and future of spectroscopy using epithermal neutrons. This meeting was the sixth in a series of workshops held in collaboration between the Science and Technology Facilities Council (UK) and the Consiglio Nazionale delle Ricerche (Italy), aimed at bringing together researchers with an interest in the use of electron-volt neutrons in spectroscopic studies [1]. This technique is termed Deep Inelastic Neutron Scattering (DINS), and also Neutron Compton Scattering (NCS) in reference to the analogy with Compton scattering of X-rays from electrons. In particular, this meeting centred jointly around experimentalists and theoreticians, formulating animated discussions as to the current overview of DINS and future horizons facing the field. The use of electron Volt neutrons for spectroscopic measurements dates back to the advent of proton-driven spallation neutron sources in the 1970s and 1980s. Following an initial scientific meeting in Los Alamos (USA) [2], the first two meetings in this series were held in Abingdon (UK) in 1995 and 1998, with subsequent meetings held in Santa Fe (USA) in 2005 [3], Oak Ridge National Laboratory (USA) in 2006 [4], and Rome, Italy; in 2010 [5]. The flagship instrument serving a continual user-programme for DINS measurements, and the main focus of this meeting, has been the VESUVIO spectrometer at ISIS [6, 7]. Subsequent instruments like SEQUOIA in the USA [8, 9] and a newer spectrometer in the Bariloche LINAC in Argentina [10, 11] have also been commissioned and began serving a growing user community. The availability of DINS measurements has extended the range of possible spectroscopic techniques that utilise neutrons into the kinematic region of high energy and momentum transfers, shown schematically in Figure 1. Spectroscopic instrument suites such as that of ISIS are thus able to probe processes on timescales across nine

  17. Advanced Neutron Spectrometer

    NASA Technical Reports Server (NTRS)

    Christl, Mark; Dobson, Chris; Norwood, Joseph; Kayatin, Matthew; Apple, Jeff; Gibson, Brian; Dietz, Kurt; Benson, Carl; Smith, Dennis; Howard, David; Rodriquez, Miguel; Watts, John; Sabra, Mohammed; Kuznetsov, Evgeny

    2013-01-01

    Energetic neutron measurements remain a challenge for space science investigations and radiation monitoring for human exploration beyond LEO. We are investigating a new composite scintillator design that uses Li6 glass scintillator embedded in a PVT block. A comparison between Li6 and Boron 10 loaded scintillators are being studied to assess the advantages and shortcomings of these two techniques. We present the details of the new Li6 design and results from the comparison of the B10 and Li6 techniques during exposures in a mixed radiation field produced by high energy protons interacting in a target material.

  18. NEUTRONIC REACTOR

    DOEpatents

    Hurwitz, H. Jr.; Brooks, H.; Mannal, C.; Payne, J.H.; Luebke, E.A.

    1959-03-24

    A reactor of the heterogeneous, liquid cooled type is described. This reactor is comprised of a central region of a plurality of vertically disposed elongated tubes surrounded by a region of moderator material. The central region is comprised of a central core surrounded by a reflector region which is surrounded by a fast neutron absorber region, which in turn is surrounded by a slow neutron absorber region. Liquid sodium is used as the primary coolant and circulates through the core which contains the fuel elements. Control of the reactor is accomplished by varying the ability of the reflector region to reflect neutrons back into the core of the reactor. For this purpose the reflector is comprised of moderator and control elements having varying effects on reactivity, the control elements being arranged and actuated by groups to give regulation, shim, and safety control.

  19. Neutron therapy of cancer

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Nellans, H. N.; Shaw, M. J.

    1969-01-01

    Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology.

  20. NEUTRON SOURCE

    DOEpatents

    Foster, J.S. Jr.

    1960-04-19

    A compact electronic device capable of providing short time high density outputs of neutrons is described. The device of the invention includes an evacuated vacuum housing adapted to be supplied with a deuterium, tritium, or other atmosphere and means for establishing an electrical discharge along a path through the gas. An energized solenoid is arranged to constrain the ionized gas (plasma) along the path. An anode bearing adsorbed or adherent target material is arranged to enclose the constrained plasma. To produce neutrons a high voltage is applied from appropriate supply means between the plasma and anode to accelerate ions from the plasma to impinge upcn the target material, e.g., comprising deuterium.