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Sample records for gamma analysis results

  1. Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

    SciTech Connect

    Dahing, Lahasen Normanshah; Yahya, Redzuan; Yahya, Roslan; Hassan, Hearie

    2014-09-03

    In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm{sup 3} and 15×15×15 cm{sup 3} were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

  2. Graphite Gamma Scan Results

    SciTech Connect

    Mark W. Drigert

    2014-04-01

    This report documents the measurement and data analysis of the radio isotopic content for a series of graphite specimens irradiated in the first Advanced Graphite Creep (AGC) experiment, AGC-1. This is the first of a series of six capsules planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphites. The AGC-1 capsule was irradiated in the Advanced Test Reactor (ATR) at INL at approximately 700 degrees C and to a peak dose of 7 dpa (displacements per atom). Details of the irradiation conditions and other characterization measurements performed on specimens in the AGC-1 capsule can be found in “AGC-1 Specimen Post Irradiation Data Report” ORNL/TM 2013/242. Two specimens from six different graphite types are analyzed here. Each specimen is 12.7 mm in diameter by 25.4 mm long. The isotope with the highest activity was 60Co. Graphite type NBG-18 had the highest content of 60Co with an activity of 142.89 µCi at a measurement distance of 47 cm.

  3. Performance test results of noninvasive characterization of Resource Conservation and Recovery Act surrogate waste by prompt gamma neutron activation analysis

    SciTech Connect

    Gehrke, R.J.; Streier, G.G.

    1997-03-01

    During FY-96, a performance test was carried out with funding from the Mixed Waste Focus Area (MWFA) of the Department of Energy (DOE) to determine the noninvasive elemental assay capabilities of commercial companies for Resource Conservation and Recovery Act (RCRA) metals present in 8-gal drums containing surrogate waste. Commercial companies were required to be experienced in the use of prompt gamma neutron activation analysis (PGNAA) techniques and to have a prototype assay system with which to conduct the test assays. Potential participants were identified through responses to a call for proposals advertised in the Commerce Business Daily and through personal contacts. Six companies were originally identified. Two of these six were willing and able to participate in the performance test, as described in the test plan, with some subsidizing from the DOE MWFA. The tests were conducted with surrogate sludge waste because (1) a large volume of this type of waste awaits final disposition and (2) sludge tends to be somewhat homogeneous. The surrogate concentrations of the above RCRA metals ranged from {approximately} 300 ppm to {approximately} 20,000 ppm. The lower limit was chosen as an estimate of the expected sensitivity of detection required by noninvasive, pretreatment elemental assay systems to be of value for operational and compliance purposes and to still be achievable with state-of-the-art methods of analysis. The upper limit of {approximately} 20,000 ppm was chosen because it is the opinion of the author that assay above this concentration level is within current state-of-the-art methods for most RCRA constituents. This report is organized into three parts: Part 1, Test Plan to Evaluate the Technical Status of Noninvasive Elemental Assay Techniques for Hazardous Waste; Part 2, Participants` Results; and Part 3, Evaluation of and Comments on Participants` Results.

  4. Calculation of the decision thresholds for radionuclides identified in gamma-ray spectra by post-processing peak analysis results

    NASA Astrophysics Data System (ADS)

    Korun, Matjaž; Vodenik, Branko; Zorko, Benjamin

    2016-03-01

    A method for calculating the decision thresholds for gamma-ray emitters, identified in gamma-ray spectrometric analyses, is described. The method is suitable for application in computerized spectra-analyzing procedures. In the calculation, the number of counts and the uncertainty in the number of counts for the peaks associated with the emitter are used. The method makes possible to calculate decision thresholds from peaks on a curved background and overlapping peaks. The uncertainty in the number of counts used in the calculation was computed using Canberra's Standard Peak Search Program (Canberra, 1986, Peak Search Algorithm Manual 07-0064). For isolated peaks, the decision threshold exceeds the value calculated from the channel contents in an energy region that is 2.5 FWHM wide, covering the background in the immediate vicinity of the peak. The decision thresholds vary by approximately 20% over a dynamic range of peak areas of about 1000. In the case of overlapping peaks, the decision threshold increases considerably. For multi-gamma-ray emitters, a common decision threshold is calculated from the decision thresholds obtained from individual gamma-ray emissions, being smaller than the smallest of the individual decision thresholds.

  5. SAS-2 galactic gamma ray results, 1

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Lamb, R. C.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1976-01-01

    Continuing analysis of the data from the SAS-2 high energy gamma-ray experiment has produced an improved picture of the sky at photon energies above 35 MeV. On a large scale, the diffuse emission from the galactic plane is the dominant feature observed by SAS-2. This galactic plane emission is most intense between galactic longitude 310 and 45 deg, corresponding to a region within 7kpc of the galactic center. Within the high-intensity region, SAS-2 observes peaks around galactic longitudes 315 deg, 330 deg, 345 deg, 0 deg, and 35 deg. These peaks appear to be correlated with such galactic features and components as molecular hydrogen, atomic hydrogen, magnetic fields, cosmic ray concentrations, and photon fields.

  6. A Three-Dimensional Analysis of the Galactic Gamma-Ray Emission Resulting from Cosmic-Ray Interaction with the Interstellar Gas and Radiation Fields

    NASA Technical Reports Server (NTRS)

    Sodraski, Thomas J.; Dwek, Eli

    1998-01-01

    This final report outlines the progress of the contractor's support for the analysis of data under ADP (NRA 96-ADP-08; Proposal No. 167-96 adp). The primary task object was to construct a 3-D model for the distribution of high-energy (20 MeV-30 GeV) gamma-ray emission in the Galactic disk. Under this task the contractor was to utilize data from the EGRET instrument on the Compton Gamma-Ray Observatory, HI and CO surveys, radio-continuum surveys at 408 MHz, 1420 MHz, 5 GHz, and 19 GHz, the COBE Diffuse Infrared Background Experiment (DIRBE) all-sky maps from I to 240 um, and ground-based B,V, J, H and K photometry. The respective contributions to the high-latitude gamma-ray emission from cosmic ray-matter interactions, inverse Compton scattering, and extra-galactic emission were to be determined.

  7. A 3-Dimensional Analysis of the Galactic Gamma-Ray Emission Resulting from Cosmic-Ray Interactions with the Interstellar Gas and Radiation Fields

    NASA Technical Reports Server (NTRS)

    Sodroski, Thomas J.; Dwek, Eli (Technical Monitor)

    2001-01-01

    The contractor will provide support for the analysis of data under ADP (NRA 96-ADP- 09; Proposal No . 167-96adp). The primary task objective is to construct a 3-D model for the distribution of high-energy (20 MeV - 30 GeV) gamma-ray emission in the Galactic disk. Under this task the contractor will utilize data from the EGRET instrument on the Compton Gamma-Ray Observatory, H I and CO surveys, radio-continuum surveys at 408 MHz, 1420 MHz, 5 GHz, and 19 GHz, the COBE Diffuse Infrared Background Experiment (DIME) all-sky maps from 1 to 240 p, and ground-based B, V, J, H, and K photometry. The respective contributions to the gamma-ray emission from cosmic ray/matter interactions, inverse Compton scattering, and extragalactic emission will be determined.

  8. Gamma Ray Bursts and recent Swift Results .

    NASA Astrophysics Data System (ADS)

    Chincarini, G.

    Due to the large activity we had during these last months with the Swift satellite I started the writing of the presentation I gave at the SAIt Catania meeting only in the middle of September. The Swift satellite, however, never rested. Since then and in addition to the results I showed at the meeting in relation to the early and steep light curves observed with the XRT telescope in the 0.2 - 10 keV band, we had fundamental discoveries among which the detection and localization of short bursts and the detection of the largest redshift ever. It obviously would be improper to discuss here the most recent results but it would also be silly in such a fast evolving topics where the day by day observations show excellent results and the observer is far ahead of the theoretician, to write an article that, from the observational point of view, would be completely obsolete. The best approach here seems to be a brief description of what was presented during the meeting briefly mentioning also some of the most recent results. We remind the reader, however, that a copious literature written, and in preparation, exists so that we urge the reader to refer to the specialized articles. This brief article will touch on the basic characteristics of the Gamma Ray Bursts (GRBs) in the Introduction (section 1) and illustrate the basic characteristics of the Swift mission in section 2. Preliminary science results will be discussed in section 3 and finally we will mention one, among many, of the main goal we plan to achieve in Cosmology via the observations of very distant GRBs.

  9. Gold analysis by the gamma absorption technique.

    PubMed

    Kurtoglu, Arzu; Tugrul, A Beril

    2003-01-01

    Gold (Au) analyses are generally performed using destructive techniques. In this study, the Gamma Absorption Technique has been employed for gold analysis. A series of different gold alloys of known gold content were analysed and a calibration curve was obtained. This curve was then used for the analysis of unknown samples. Gold analyses can be made non-destructively, easily and quickly by the gamma absorption technique. The mass attenuation coefficients of the alloys were measured around the K-shell absorption edge of Au. Theoretical mass attenuation coefficient values were obtained using the WinXCom program and comparison of the experimental results with the theoretical values showed generally good and acceptable agreement. PMID:12485656

  10. Blazars and gamma-ray cosmology: recent and prospective results

    NASA Astrophysics Data System (ADS)

    Biteau, Jonathan; Williams, David A.

    2016-01-01

    Blazars are dazzling gamma-ray beacons shedding light on some of the darkest mysteries of modern-day astroparticle physics. Some of these mysteries include the light content of the universe, including the UV-IR background, the emission of first stars and of organic molecules; large-scale magnetic fields and their potential primordial origin; spacetime structure, with the potential for Lorentz-invariance violations near the Planck scale; and the search for new interaction channels with photons, e.g. in the form of axion-like particles. These crucial scientific topics can be studied through the signatures of billion-year propagation of GeV-TeV gamma rays that reach Earth from astrophysical sources. We discuss how spectral imprints in data from ground-based and satellite experiments are beginning to answer some of the fundamental questions of gamma-ray cosmology. Recent results, obtained with increased datasets and advanced analysis techniques, are opening the path for future observatories. We examine the areas that remain to be explored, in particular by the proposed Cherenkov Telescope Array, CTA.

  11. Analysis of High-Fold Gamma Data

    SciTech Connect

    Beyer, C.J.; Cromaz, M.; Radford, D.C.

    1998-08-10

    Historically, {gamma}-{gamma} and {gamma}-{gamma}-{gamma} coincidence spectra were utilized to build nuclear level schemes. With the development of large detector arrays, it has became possible to analyze higher fold coincidence data sets. This paper briefly reports on software to analyze 4-fold coincidence data sets that allows creation of 4-fold histograms (hypercubes) of at least 1024 channels per side (corresponding to a 43 gigachannel data space) that will fit onto a few gigabytes of disk space, and extraction of triple-gated spectra in a few seconds. Future detector arrays may have even higher efficiencies, and detect an many as 15 or 20 {gamma} rays simultaneously; such data will require very different algorithms for storage and analysis. Difficulties inherent in the analysis of such data are discussed, and two possible new solutions are presented, namely adaptive list-mode systems and list-list-mode storage.

  12. AI gamma-ray burst classification: Methodology/preliminary results

    NASA Astrophysics Data System (ADS)

    Hakkila, Jon; Haglin, David J.; Roiger, Richard J.; Mallozzi, Robert S.; Pendleton, Geoffrey N.; Meegan, Charles A.

    1998-05-01

    Artificial intelligence (AI) classifiers can be used to classify unknowns, refine existing classification parameters, and identify/screen-out ineffectual parameters. We present an AI methodology for classifying gamma-ray bursts, along with some preliminary results.

  13. A comparative analysis of gamma and hadron families at the superhigh energies recorded in experiment Pamir

    NASA Technical Reports Server (NTRS)

    Azimov, S. A.; Mulladjanov, E. J.; Nosov, A. N.; Nuritdinov, H.; Talipov, D. A.; Halilov, D. A.; Yuldashbaev, T. S.

    1985-01-01

    A comparative analysis of hadron and gamma families which have undergone the decascading procedure is made. Results are compared with different models of interactions. In hadron families with energies Summary E sub H sup gamma 20 TeV as well as in gamma families with energies Summary E sub gamma 70 TeV, increasing azimuthal anisotropy is observed.

  14. TEST RESULTS FROM GAMMA IRRADIATION OF ALUMINUM OXYHYDROXIDES

    SciTech Connect

    Fisher, D.; Westbrook, M.; Sindelar, R.

    2012-02-01

    Hydrated metal oxides or oxyhydroxides boehmite and gibbsite that can form on spent aluminum-clad nuclear fuel assemblies during in-core and post-discharge wet storage were exposed as granular powders to gamma irradiation in a {sup 60}Co irradiator in closed laboratory test vessels with air and with argon as separate cover gases. The results show that boehmite readily evolves hydrogen with exposure up to a dose of 1.8 x 10{sup 8} rad, the maximum tested, in both a full-dried and moist condition of the powder, whereas only a very small measurable quantity of hydrogen was generated from the granular powder of gibbsite. Specific information on the test setup, sample characteristics, sample preparation, irradiation, and gas analysis are described.

  15. First Results from the Swift Gamma Ray Burst Mission

    NASA Technical Reports Server (NTRS)

    Gehreis, Neil

    2005-01-01

    Swift is now in orbit after a beautiful launch on November 20, 2004. It is a multiwavelength observatory designed specifically to study the fascinating gamma-ray bursts. The goals are to determine the origin of bursts and use them to probe the early Universe. A new-technology wide-field gamma-ray camera detects more than a hundred bursts per year. Sensitive narrow-field X-ray and UV/optical telescopes are pointed at the burst location in 20 to 70 sec by an autonomously controlled "swift" spacecraft. For each burst, arcsec positions are determined and optical/UV/X-ray/gamma-ray spectrophotometry performed. Information is also rapidly sent to the ground to a team of more than 50 observers at telescopes around the world. First results from the mission will be presented, including observations of bright GRBs, faint GRBs, short GRBs and a super-giant flare from the soft gamma repeater SGRl806-20.

  16. A Three-Dimensional Analysis of the Galactic Gamma-Ray Emission Resulting from Cosmic-Ray Interactions with the Interstellar Gas and Radiation Fields

    NASA Technical Reports Server (NTRS)

    Sodroski, Thomas J.; Dwek, Eli

    2000-01-01

    The primary task objective is to construct a 3-D model for the distribution of high-energy (20 MeV - 30 GeV) gamma-ray emission in the Galactic disk. Under this task the contractor will utilize data from the EGRET instrument on the Compton Gamma-Ray Observatory, H I and CO surveys, radio-continuum surveys at 408 MHz, 1420 MHz, 5 GHz, and 19 GHz, the COBE Diffuse Infrared Background Experiment (DIRBE) all-sky maps from 1 to 240 microns, and ground-based B, V, J, H, and K photometry. The respective contributions to the gamma-ray emission from cosmic ray/matter interactions, inverse Compton scattering, and extragalactic emission will be determined.

  17. A mass spectrometric analysis of {gamma}-GPS films

    SciTech Connect

    Dillingham, R.G.; Boerio, F.J.; Bertelsen, C.; Savina, M.R.; Lykke, K.R.; Calaway, W.F.

    1996-06-01

    {gamma}-glycidoxypropyltrimethoxysilane ({gamma}-GPS) is used for pre-treatment of grit-blasted aluminum before adhesive bonding. This paper discusses analysis of non-reflective grit-blasted surfaces using mass spectrometry of species that were either sputtered off using an ion beam or thermally desorbed as neutrals using a pulsed laser and then post-ionized using a secondary laser. Results show that fragmentation is excessive and structural information is difficult to obtain from the spectra.

  18. Elemental PGNAA analysis using gamma-gamma coincidence counting with the library least-squares approach

    NASA Astrophysics Data System (ADS)

    Metwally, Walid A.; Gardner, Robin P.; Mayo, Charles W.

    2004-01-01

    An accurate method for determining elemental analysis using gamma-gamma coincidence counting is presented. To demonstrate the feasibility of this method for PGNAA, a system of three radioisotopes (Na-24, Co-60 and Cs-134) that emit coincident gamma rays was used. Two HPGe detectors were connected to a system that allowed both singles and coincidences to be collected simultaneously. A known mixture of the three radioisotopes was used and data was deliberately collected at relatively high counting rates to determine the effect of pulse pile-up distortion. The results obtained, with the library least-squares analysis, of both the normal and coincidence counting are presented and compared to the known amounts. The coincidence results are shown to give much better accuracy. It appears that in addition to the expected advantage of reduced background, the coincidence approach is considerably more resistant to pulse pile-up distortion.

  19. Gamma-Ray Library and Uncertainty Analysis: Passively Emitted Gamma Rays Used in Safeguards Technology

    SciTech Connect

    Parker, W

    2009-09-18

    Non-destructive gamma-ray analysis is a fundamental part of nuclear safeguards, including nuclear energy safeguards technology. Developing safeguards capabilities for nuclear energy will certainly benefit from the advanced use of gamma-ray spectroscopy as well as the ability to model various reactor scenarios. There is currently a wide variety of nuclear data that could be used in computer modeling and gamma-ray spectroscopy analysis. The data can be discrepant (with varying uncertainties), and it may difficult for a modeler or software developer to determine the best nuclear data set for a particular situation. To use gamma-ray spectroscopy to determine the relative isotopic composition of nuclear materials, the gamma-ray energies and the branching ratios or intensities of the gamma-rays emitted from the nuclides in the material must be well known. A variety of computer simulation codes will be used during the development of the nuclear energy safeguards, and, to compare the results of various codes, it will be essential to have all the {gamma}-ray libraries agree. Assessing our nuclear data needs allows us to create a prioritized list of desired measurements, and provides uncertainties for energies and especially for branching intensities. Of interest are actinides, fission products, and activation products, and most particularly mixtures of all of these radioactive isotopes, including mixtures of actinides and other products. Recent work includes the development of new detectors with increased energy resolution, and studies of gamma-rays and their lines used in simulation codes. Because new detectors are being developed, there is an increased need for well known nuclear data for radioactive isotopes of some elements. Safeguards technology should take advantage of all types of gamma-ray detectors, including new super cooled detectors, germanium detectors and cadmium zinc telluride detectors. Mixed isotopes, particularly mixed actinides found in nuclear reactor

  20. COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

    EPA Science Inventory



    COMPUTER ANALYSIS OF PLANAR GAMMA CAMERA IMAGES

    T Martonen1 and J Schroeter2

    1Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. EPA, Research Triangle Park, NC 27711 USA and 2Curriculum in Toxicology, Unive...

  1. Recent high energy gamma-ray results from SAS-2

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Ogelman, H. B.; Ozel, M. E.; Tumer, T.; Lamb, R. C.

    1977-01-01

    Recent developments in gamma-ray astronomy due to the results from SAS-2 have focused on two areas. First, the emission from the plane of the Galaxy is the dominant feature in the gamma-ray sky. The galactic latitude and longitude distributions are consistent with the concept that the high-energy radiation originates from cosmic rays interacting with interstellar matter, and the measurements support a galactic origin for cosmic rays. Second, searches of the SAS-2 data for emission from localized sources have shown three strong discrete gamma-ray sources: the Crab nebula and PSR 0531 + 21, the Vela supernova remnant and PSR 0833-45, and a source near galactic coordinates 193 deg longitude, +3 deg latitude, which does not appear to be associated with other known celestial objects. Evidence has also been found for pulsed gamma-ray emission from two other radio pulsars, PSR 1818-04 and PSR 1747-46. A localized source near longitudes 76-80 deg may be associated with the X-ray source Cyg X-3.

  2. Titanium-Water Thermosyphon Gamma Radiation Effects and Results

    NASA Technical Reports Server (NTRS)

    Sanzi, James L.; Jaworske, Donald A.; Goodenow, Debra A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some exposure to gamma irradiation. Non-condensable gas formation from radiation may breakdown water over time and render a portion of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature with accelerated gamma irradiation exposures on the same order of magnitude that is expected in eight years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon; evaporator, condenser, and condenser end cap. Some non-condensable gas was evident, however thermosyphon performance was not affected because the non-condensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of non-condensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the non-condensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of selected thermosyphons at temperature and in a vacuum chamber revealed that the non-condensable gas likely diffused out of the thermosyphons over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  3. Titanium-Water Thermosyphon Gamma Radiation Exposure and Results

    NASA Technical Reports Server (NTRS)

    Sanzi, James, L.A; Jaworske, Donald, A.; Goodenow, Debra, A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of water over time may render portions of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature under accelerated gamma irradiation, with exposures on the same order of magnitude as that expected in 8 years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon: evaporator, condenser, and condenser end cap. Some noncondensable gas was evident; however, thermosyphon performance was not affected because the noncondensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of noncondensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the noncondensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of one thermosyphon in a vacuum chamber and at temperature revealed that the noncondensable gas diffused out of the thermosyphon over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  4. Results of mobile gamma scanning activities in Tonawanda, New York

    SciTech Connect

    Cottrell, W.D.; Witt, D.A.; Rodriguez, R.E.; Carrier, R.F.

    1990-12-01

    During the 1940s, the Linde Air Products Division of Union Carbide operated a plant in Tonawanda, New York, for the Manhattan Engineer District (MED) and the Atomic Energy Commission (AEC). Uranium production and some nickel processing were conducted at the site. It is the policy of the US Department of Energy (DOE) to verify that radiological conditions at such sites or facilities comply with current DOE guidelines. Guidelines for release and use of such sites have become more stringent as research has provided more information since previous cleanups. The Formerly Utilized Sites Remedial Action Program (FUSRAP) was established as part of that effort to confirm the closeout status of facilities under contract to agencies preceding DOE during early nuclear energy development. Under the FUSRAP program, the Linde site itself has been previously investigated to determine the extent of on-site radiological contamination. As a precaution to insure that no residual radioactive materials were transported off-site, the Department of Energy requested that ORNL survey the area in the vicinity of the Linde Plant, the waste water treatment facility on Tower Road, the Sheridan Park Fire Station (District 4), and the Tonawanda Landfill to assess whether any residual radioactive material could be detected. The survey was conducted the week of April 3, 1990. Results of analysis of soil samples from the Tonawanda Landfill revealed slightly elevated concentrations of {sup 238}U and {sup 226}Ra suggestive of residuals from former Linde Plant operations. Therefore, it is recommended that additional surveying of the landfill property and of Sheridan Creek from south of the Linde property to its confluence with the Niagara River be conducted. The survey should include the measurement of gamma radiation levels and radionuclide analysis of silt samples. 6 refs., 4 figs., 1 tab.

  5. Recent Results from Gamma-Ray Energy Tracking Array GRETINA

    NASA Astrophysics Data System (ADS)

    Lee, I.-Yang

    2012-10-01

    The gamma-ray energy tracking array GRETINA uses 28 Ge crystals, each with 36 segments, to cover .5ex1 -.1em/ -.15em.25ex4 of the 4π solid angle. The gamma ray tracking technique uses detailed pulse shape information from each of the segments. These pulses are analyzed to determine the energy, time, and three-dimensional positions of all gamma-ray interactions. This information is then utilized, together with the characteristics of Compton scattering and pair-production processes, to track the scattering sequences of the gamma rays. Tracking arrays will give higher efficiency, better peak-to-total ratio and much higher position resolution, and thus increases the detection sensitivity by factors of several hundred compared to current arrays used in nuclear physics research. Particularly, for fast beam experiments tracking will provide spectra quality comparable to that from a Compton suppressed array, such as Gammasphere, while having the position resolution needed for the accurate Doppler correction comparable to detectors designed for good position resolution such as SeGA. GRETINA construction at the 88-Inch Cyclotron at LBNL was completed in March 2011. Extensive engineering and commissioning runs were carried out using radioactive sources, and beams from the Cyclotron until March 2012. The data obtained have been used to debug and improve its performance. After the commissioning period, GRETINA was moved to NSCL MSU and installed at the target position of the S800 spectrograph. The experimental program with a total of twenty four experiments will start in July 2012 after successful commissioning runs. I will present preliminary results from these runs and discuss future research plans.

  6. Analysis of noise power spectrum of gamma rays camera

    NASA Astrophysics Data System (ADS)

    Xie, Hongwei; Zhang, Faqiang; Zhang, Jianhua; Chen, Jinchuan; Chen, Dingyang; Li, Linbo

    2014-01-01

    Gamma rays camera is widely used in many studies, including the image diagnostics of the radiation sources, flash photography, and nondestructive assessment (NDA), etc. As a major component of the high sensitivity gamma rays camera, the MCP image intensifier is characterized in the intensified image, tunable shutter time and gain. The gamma rays camera is consisting with rays-fluorescence convertor, the optical imaging system, the MCP image intensifier, CCD and other devices. The performance of the gamma rays camera is mainly dependent on such parameters as the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE), etc. All of the parameters are somewhat limited by the noise characteristics of the system. Compared with the standard derivative noise distribution, the NPS, which can reflect the evolution characteristics of the noise of the imaging system with the change of the spatial frequency, could convey more information on the noise distribution in the system. In this paper, theoretical analysis is presented on the major sources of the noise in the gamma rays camera. Based on the analysis, the noise power spectra of the gamma rays camera were calibrated under various radiation dosages respectively with the visible light and gamma rays radiation sources (0.2MeV and 1.25MeV in energy, respectively). As indicated by the experimental results, the noise is majorly induced by the fluctuations of the gain of the MCP image intensifier. And the remarkable noise peak occurs nearby the spatial frequency of about 0.633 Hz/mm. And almost the same phenomena were found with both the 0.2MeV and 1.25MeV radiation energy. Besides, the noise power spectra are in circular symmetrical distribution, whose intensities are rapidly decreased with the increasing spatial frequencies.

  7. Gamma-400 Science Objectives Built on the Current HE Gamma-Ray and CR Results

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander; Mitchell, John; Thompson, David

    2012-01-01

    The main scientific interest of the Russian Gamma-400 team: Observe gamma-rays above approximately 50 GeV with excellent energy and angular resolution with the goals of: (1) Studying the fine spectral structure of the isotropic high-energy gamma-radiation, (2) Attempting to identify the many still-unidentified Fermi-LAT gamma-ray sources. Gamma-400 will likely be the only space-based gamma-ray observatory operating at the end of the decade. In our proposed Gamma-400-LE version, it will substantially improve upon the capabilities of Fermi LAT and AGILE in both LE and HE energy range. Measuring gamma-rays from approx 20 MeV to approx 1 TeV for at least 7 years, Gamma-400-LE will address the topics of dark matter, cosmic ray origin and propagation, neutron stars, flaring pulsars, black holes, AGNs, GRBs, and actively participate in multiwavelength campaigns.

  8. Taking into account photofission effects in gamma-activation analysis

    SciTech Connect

    Dayvdov, M.G.; Kishel'gof, V.V.; Naumov, A.P.; Trukhov, A.V.

    1986-11-01

    The authors proposed a method for calculating the effect of photofission of U and Th, which is based on the well-known laws of physics of photofission and methods for calculating the activity of fission products. The authors compared the results of numerical calculations of the gamma spectra of photofission products with the measurements performed with a Ge (Li) detector with the spectra from activated model samples of U and Th. The method developed enables calculating the coefficients of interference and is also applicable to the solution of the problems of optimization of gamma activation analysis taking into account U and Th fission.

  9. 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.

  10. SAS-2 galactic gamma-ray results. 1: Diffuse emission

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Lamb, R. C.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    Continuing analysis of the data from the SAS-2 high energy gamma ray experiment has produced an improved picture of the sky at photon energies above 35 MeV. On a large scale, the diffuse emission from the galactic plane is the dominant feature observed by SAS-2. This galactic plane emission is most intense between galactic longitudes 310 deg and 45 deg, corresponding to a region within 7 kpc of the galactic center. Within the high-intensity region, SAS-2 observes peaks around galactic longitudes 315, 330, 345, 0, and 35 deg. These peaks appear to be correlated with galactic features and components such as molecular hydrogen, atomic hydrogen, magnetic fields, cosmic-ray concentrations, and photon fields.

  11. [Qualitative and quantitative gamma-hydroxybutyrate analysis].

    PubMed

    Petek, Maja Jelena; Vrdoljak, Ana Lucić

    2006-12-01

    Gamma-hydroxybutyrate (GHB) is a naturally occurring compound present in the brain and peripheral tissues of mammals. It is a minor metabolite and precursor of gamma-aminobutyric acid (GABA). Just as GABA, GHB is believed to play a role in neurotransmission. GHB was first synthesized in vitro in 1960, when it revealed depressive and hypnotic effects on the central nervous system. In 1960s it was used as an anaesthetic and later as an alternative to anabolic steroids, in order to enhance muscle growth. However, after it was shown that it caused strong physical dependence and severe side effects, GHB was banned. For the last fifteen years, GHB has been abused for its intoxicating effects such as euphoria, reduced inhibitions and sedation. Illicitly it is available as white powder or as clear liquid. Paradoxically GHB can easily be manufactured from its precursor gamma-butyrolactone (GBL), which has not yet been banned. Because of many car accidents and criminal acts in which it is involved, GHB has become an important object of forensic laboratory analysis. This paper describes gas and liquid chromatography, infrared spectroscopy, microscopy, colourimetry and nuclear magnetic resonance as methods for detection and quantification of GHB in urine and illicit products. PMID:17265679

  12. SAS-2 galactic gamma ray results. 2. Localized sources

    NASA Technical Reports Server (NTRS)

    Hartman, R. C.; Fichtel, C. E.; Kniffen, D. A.; Lamb, R. C.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1976-01-01

    Gamma-ray emission was detected from the radio pulsars PSR1818-04 and PSR1747-46, in addition to the previously reported gamma-ray emission from the Crab and Vela pulsars. Since the Crab pulsar is the only one observed in the optical and X-ray bands, these gamma-ray observations suggest a uniquely gamma-ray phenomenon occurring in a fraction of the radio pulsars. Using distance estimates it is found that PSR1818-04 has a gamma-ray luminosity comparable to that of the Crab pulsar, while the luminosities of PSR1747-46 and the Vela pulsar are approximately an order of magnitude lower. This survey of SAS-2 data for pulsar correlations has also yielded upper limits to gamma-ray luminosity for 71 other radio pulsars.

  13. SAS-2 galactic gamma-ray results. 2: Localized sources

    NASA Technical Reports Server (NTRS)

    Hartman, R. C.; Fichtel, C. E.; Kniffen, D. A.; Lamb, R. C.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    Gamma ray emission was detected from the radio pulsars PSR 1818-04 and PSR 1747-46, in addition to the previously reported gamma ray emission from the Crab and Vela pulsars. Because the Crab pulsar is the only one observed in the optical and X-ray bands, these gamma ray observations suggest a uniquely gamma ray phenomenon occurring in a fraction of the radio pulsars. PSR 1818-04 has a gamma ray luminosity comparable to that of the Crab pulsar, whereas the luminosities of PSR 1747-46 and the Vela pulsar are approximately an order of magnitude lower. SAS-2 data for pulsar correlations yielded upper limits to gamma ray luminosity for 71 other radio pulsars. For five of the closest pulsars, upper limits for gamma ray luminosity are found to be at least three orders of magnitude lower than that of the Crab pulsar. Gamma ray enhancement near the Milky Way satellite galaxy and the galactic plane in the Cygnus region is also discussed.

  14. Results of mobile gamma scanning activities in St. Louis, Missouri

    SciTech Connect

    Rodriguez, R E; Witt, D A; Cottrell, W D; Carrier, R F

    1991-06-01

    From 1942 through approximately 1966, the Mallinckrodt Chemical Works operated four plants in St. Louis, Missouri, for the Manhattan Engineer District and the Atomic Energy Commission. A variety of production processes using uranium- and radium-bearing ore materials were performed at the plants. It is the policy of the DOE to verify that radiological conditions at such sites or facilities comply with current DOE guidelines. Guidelines for release and use of such sites have become more stringent as research has provided more information since previous cleanups. The Formerly Utilized Sites Remedial Action Program (FUSRAP) was established as part of that effort to confirm the closeout status of facilities under contract to agencies preceding DOE during early nuclear energy development. Under the FUSRAP program, the Mallinckrodt properties have been previously investigated to determine the extent of on-site radiological contamination. At the request of DOE, Oak Ridge National Laboratory (ORNL) conducted a survey in May 1990, of public roadways and suspected haul routes between the Mallinckrodt plant and storage sites in St. Louis to ensure that no residual radioactive materials were conveyed off-site. A mobile gamma scanning van with an on-board computer system was used to identify possible anomalies. Suspect areas are those displaying measurements deviating from gamma exposure rates identified as typical for radiologically unenhanced areas in the vicinity of the areas of interest. The instrumentation highlighted three anomaly locations each of which measured less than 1m{sup 2} in size. None of the slightly elevated radiation levels originated from material associated with former AEC-related processing operations in the area. The anomalies resulted from elevated concentrations of radionuclides present in phosphate fertilizers, increased thorium in road-base gravel, and emanations from the radioactive storage site near the Latty Avenue airport. 9 refs., 3 figs.

  15. Analysis of Phobos mission gamma ray spectra from Mars

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Evans, L. G.; Starr, R.; Floyd, S. R.; Squyres, S. W.; Whelan, J. T.; Bamford, G. J.; Coldwell, R. L.; Rester, A. C.; Surkov, Iu. A.

    1992-01-01

    The determination of the elemental composition of the surface of a planetary body can be achieved, in many cases, by remote-sensing gamma ray spectroscopy. A gamma ray spectrometer was carried on the Soviet spacecraft Phobos-2, and obtained data while in an elliptical orbit around Mars. Results of two independent approaches to data analysis, one by the Soviet group and one by an American group are reported. The results for five elements are given for two different orbits of Mars. Major geologic units that contribute to the signal for each orbit have been identified. The results from the two techniques are in general agreement and there appear to be no geologically significant differences between the results for each orbit.

  16. Gamma Detector Response and Analysis Software - Light

    Energy Science and Technology Software Center (ESTSC)

    2004-06-14

    GADRAS is used to analyze gamma-ray spectra, which may be augmented by neutron count rate information. The fundamental capabilities of GADRAS are imparted by physics-based detector response functions for a variety of gamma ray and neufron detectors. The software has provisions for characterizing detector response parameters so that specta can be computed accurately over the range 30keV key to II MeV. Associated neutron detector count rates can also be computed for characterized detectors. GADRAS incorporatesmore » a variety of analysis algorithms that utilize the computed spectra. The full version of GADRAS incorporates support for computation of radiation leakages from complex source models, but this capability is not supported by GADRAS-LT. GADRAS has been and will continue to be disseminated free of charge to government agencies and National Laboratories as OUO software. GADRAS-LT is a limited software version that was prepared for exclusive use of our Technology Transfer parnter Thermo Electron (TE). TE will use the software to characterize and test radiation detectors that are fabricated under the terms of our partnership. The development of these sensors has been defined as a National Security priority by our sponsor, NNSA/NA-20, by DHS/S&T, and by SNL president Paul Robinson. Although GADRAS-LT is OUO, features that are not essential to the detector development have been removed. TE will not be licensed to commercialize GADRAS-LT or to distribute it to third parties.« less

  17. Structure in gamma ray burst time profiles: Statistical Analysis 1

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1992-01-01

    Since its launch on April 5, 1991, the Burst And Transient Source Experiment (BATSE) has observed and recorded over 500 gamma-ray bursts (GRB). The analysis of the time profiles of these bursts has proven to be difficult. Attempts to find periodicities through Fourier analysis have been fruitless except one celebrated case. Our goal is to be able to qualify the observed time-profiles structure. Before applying this formation to bursts, we have tested it on profiles composed of random Poissonian noise. This paper is a report of those preliminary results.

  18. Final Results from the KTeV Experiment on the Decay K(L) ---> pi0 gamma gamma

    SciTech Connect

    Abouzaid, E.; Arenton, M.; Barker, A.R.; Bellantoni, L.; Blucher, E.; Bock, G.J.; Cheu, E.; Coleman, R.; Corcoran, M.D.; Cox, B.; Erwin, A.R.; /Wisconsin U., Madison /Campinas State U.

    2008-05-01

    The authors report on a new measurement of the branching ratio B(K{sub L} {yields} {pi}{sup 0}{gamma}{gamma}) using the KTeV detector. They reconstruct 1982 events with an estimated background of 608, that results in B(K{sub L} {yields} {pi}{sup 0}{Gamma}{gamma}) = (1.29 {+-} 0.03{sub stat} {+-} 0.05{sub syst}) x 10{sup -6}. They also measure the parameter, a{sub V}, which characterizes the strength of vector meson exchange terms in this decay. They find a{sub V} = -0.31 {+-} 0.05{sub stat} {+-} 0.07{sub syst}. These results utilize the full KTeV data set collected from 1997 to 2000 and supersede earlier KTeV measurements of the branching ratio and a{sub V}.

  19. Plutonium Isotopic Gamma-Ray Analysis

    Energy Science and Technology Software Center (ESTSC)

    1992-01-08

    The MGA8 (Multiple Group Analysis) program determines the relative abundances of plutonium and other actinide isotopes in different materials. The program analyzes spectra taken of such samples using a 4096-channel germanium (Ge) gamma-ray spectrometer. The code can be run in a one or two detector mode. The first spectrum, which is required and must be taken at a gain of 0.075 Kev/channel with a high resolution planar detector, contains the 0-300 Kev energy region. Themore » second spectrum, which is optional, must be taken at a gain of 0.25 Kev/channel; it becomes important when analyzing high burnup samples (concentration of Pu241 greater than one percent). Isotopic analysis precisions of one percent or better can be obtained, and no calibrations are required. The system also measures the abundances of U235, U238, Np237, and Am241. A special calibration option is available to perform a one-time peak-shape characterization when first using a new detector system.« less

  20. Gamma-ray spectral analysis algorithm library

    Energy Science and Technology Software Center (ESTSC)

    2013-05-06

    The routines of the Gauss Algorithms library are used to implement special purpose products that need to analyze gamma-ray spectra from Ge semiconductor detectors as a part of their function. These routines provide the ability to calibrate energy, calibrate peakwidth, search for peaks, search for regions, and fit the spectral data in a given region to locate gamma rays.

  1. Gamma-ray Spectral Analysis Algorithm Library

    Energy Science and Technology Software Center (ESTSC)

    1997-09-25

    The routines of the Gauss Algorithm library are used to implement special purpose products that need to analyze gamma-ray spectra from GE semiconductor detectors as a part of their function. These routines provide the ability to calibrate energy, calibrate peakwidth, search for peaks, search for regions, and fit the spectral data in a given region to locate gamma rays.

  2. Mu2e Neutron/Gamma Background Analysis

    NASA Astrophysics Data System (ADS)

    Rosendahl, Morgan; Ahmed, Mohamed; Alexander, Damien; Daniel, Aji; Hungerford, Ed; Sikora, Mark; Alcap Collaboration

    2015-10-01

    In Mu2e, a muon-to-electron conversion experiment that will search for neutrinoless lepton conversion with a single event sensitivity of 10-16, a large flux of neutrons with energies less than 10 MeV are emitted after muon capture in the stopping target. These neutrons, and gamma radiation resulting from their absorption, comprise a major component of experimental backgrounds. However, they are not currently sufficiently understood to reliably mitigate single-event-upsets in the readout electronics and time-to-failure of the detector components. At the Paul Scherrer Institute, PSI, a program was undertaken to measure neutron and charged particle emission after muon capture in targets of interest. Two BC501A neutron counters, a Ge, and a LaBr3 detector were used to measure the rates and spectra of emitted neutrons, X-rays, and gammas. The ongoing analysis of this data will provide characterization of the neutron and gamma spectra at low energies. Because the lifetime of a captured muon is nearly a microsecond, the neutron energy spectrum must be determined by unfolding methods. This presentation will discuss the experiment, neutron detector calibrations, and the progress of the analysis.

  3. GRABGAM Analysis of Ultra-Low-Level HPGe Gamma Spectra

    SciTech Connect

    Winn, W.G.

    1999-07-28

    The GRABGAM code has been used successfully for ultra-low level HPGe gamma spectrometry analysis since its development in 1985 at Savannah River Technology Center (SRTC). Although numerous gamma analysis codes existed at that time, reviews of institutional and commercial codes indicated that none addressed all features that were desired by SRTC. Furthermore, it was recognized that development of an in-house code would better facilitate future evolution of the code to address SRTC needs based on experience with low-level spectra. GRABGAM derives its name from Gamma Ray Analysis BASIC Generated At MCA/PC.

  4. Fast Fourier transformation results from gamma-ray burst profiles

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa; Norris, Jay P.; Fishman, Gerald J.; Meegan, Charles A.; Wilson, Robert B.; Paciesas, W. S.

    1992-01-01

    Several gamma-ray bursts in the BATSE data have sufficiently long durations and complex temporal structures with pulses that appear to be spaced quasi-periodically. In order to test and quantify these periods we have applied fast Fourier transformations (FFT) to all these events. We have also performed cross spectral analyses of the FFT of the two extreme (high-low) energy bands in each case to determine the lead/lag of the pulses in different energies.

  5. Dipole analysis on EGRET data of extragalactic gamma ray background radiation

    NASA Technical Reports Server (NTRS)

    Lin, Ying-Chi

    1990-01-01

    A dipole analysis on the EGRET (Energetic Gamma-Ray Experimental Telescope) data seems to be one of the numerous subjects that can be investigated for the extragalactic gamma ray background radiation. By the end of the first one and half years after launch, the all-sky survey program of GRO (Gamma Ray Observatory) will be completed. The EGRET detector will cover the full sky area fairly well by that time. A set of gamma ray data suitable for dipole moment calculations will be available. Furthermore, there now exist in the literature several dipole anisotropy results calculated for optical and infrared observations on the distribution of galaxies in the full sky. The results of dipole moment analysis from gamma ray observation can be compared with those at other wavebands, and hopefully some deeper understanding can be gained on the large scale structure of the Universe.

  6. RADSAT Benchmarks for Prompt Gamma Neutron Activation Analysis Measurements

    SciTech Connect

    Burns, Kimberly A.; Gesh, Christopher J.

    2011-07-01

    The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples. High-resolution gamma-ray spectrometers are used in these applications to measure the spectrum of the emitted photon flux, which consists of both continuum and characteristic gamma rays with discrete energies. Monte Carlo transport is the most commonly used simulation tool for this type of problem, but computational times can be prohibitively long. This work explores the use of multi-group deterministic methods for the simulation of coupled neutron-photon problems. The main purpose of this work is to benchmark several problems modeled with RADSAT and MCNP to experimental data. Additionally, the cross section libraries for RADSAT are updated to include ENDF/B-VII cross sections. Preliminary findings show promising results when compared to MCNP and experimental data, but also areas where additional inquiry and testing are needed. The potential benefits and shortcomings of the multi-group-based approach are discussed in terms of accuracy and computational efficiency.

  7. Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis

    NASA Astrophysics Data System (ADS)

    Xie, Xufei; Zhang, Xing; Yuan, Xi; Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Fan, Tieshuan; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2012-09-01

    Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

  8. Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis

    SciTech Connect

    Xie Xufei; Zhang Xing; Yuan Xi; Chen Jinxiang; Li Xiangqing; Zhang Guohui; Fan Tieshuan; Yuan Guoliang; Yang Jinwei; Yang Qingwei

    2012-09-15

    Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

  9. Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis.

    PubMed

    Xie, Xufei; Zhang, Xing; Yuan, Xi; Chen, Jinxiang; Li, Xiangqing; Zhang, Guohui; Fan, Tieshuan; Yuan, Guoliang; Yang, Jinwei; Yang, Qingwei

    2012-09-01

    Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described. PMID:23020376

  10. Preliminary results on SAS-2 observations of greater than 30 MeV gamma radiation

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Fichtel, C. E.; Hartman, R. C.

    1963-01-01

    A description is given of the SAS-2 detector and its measurements of gamma ray sources greater than 30 MeV. Results indicate that gamma rays come from discrete energetic sources, the galactic plane, and diffuse presumably extragalactic regions not associated with the galactic plane.

  11. Measurement and analysis of quadruple ({alpha}{gamma}{gamma}) angular correlations for high spin states of {sup 24}Mg.

    SciTech Connect

    Wiedenhover, I.; Wuosmaa, A. H.; Lister, C. J.; Carpenter, M. P.; Janssens, R. V. F.; Amro, H.; Caggiano, J.; Heinz, A.; Kondev, F. G.; Lauritsen, T.; Siem, S.; Sonzogni, A.; Bhattacharyya, P.; Devlin, M.; Sarantites, D. G.; Sobotka, L. G.

    2000-10-30

    The high-lying, {alpha}-decaying states in {sup 24}Mg have been studied by measuring the complete decay path of {alpha} and {gamma} emissions using five segmented Silicon detectors in conjunction with GAMMASPHERE. The authors analyzed the ({alpha}{gamma}) triple angular correlations and, for the first time, ({alpha}{gamma}{gamma}) quadruple correlations. The data analysis is based on a new Fourier transformation technique. The power of the technique is demonstrated.

  12. Total Gamma Count Rate Analysis Method for Nondestructive Assay Characterization

    SciTech Connect

    Cecilia R. Hoffman; Yale D. Harker

    2006-03-01

    A new approach to nondestructively characterize waste for disposal, based on total gamma response, has been developed at the Idaho Cleanup Project by CH2M-WG Idaho, LLC and Idaho State University, and is called the total gamma count rate analysis method. The total gamma count rate analysis method measures gamma interactions that produce energetic electrons or positrons in a detector. Based on previous experience with waste assays, the radionuclide content of the waste container is then determined. This approach potentially can yield minimum detection limits of less than 10 nCi/g. The importance of this method is twofold. First, determination of transuranic activity can be made for waste containers that are below the traditional minimum detection limits. Second, waste above 10 nCi/g and below 100 nCi/g can be identified, and a potential path for disposal resolved.

  13. Spreadsheet analysis of gamma spectra for nuclear material measurements

    SciTech Connect

    Mosby, W.R.; Pace, D.M.

    1990-01-01

    A widely available commercial spreadsheet package for personal computers is used to calculate gamma spectra peak areas using both region of interest and peak fitting methods. The gamma peak areas obtained are used for uranium enrichment assays and for isotopic analyses of mixtures of transuranics. The use of spreadsheet software with an internal processing language allows automation of routine analysis procedures increasing ease of use and reducing processing errors while providing great flexibility in addressing unusual measurement problems. 4 refs., 9 figs.

  14. New Results on Soft Gamma Repeaters and Gamma-Ray Bursts with INTEGRAL

    NASA Astrophysics Data System (ADS)

    Hurley, K.

    2005-12-01

    INTEGRAL has proven to be an excellent mission for the study of bursts, with speed, accuracy, and sensitivity rivalling those of Swift. Gamma-ray bursts are detected both within the IBIS field of view at a rate of about 10/year, and by the SPI anticoincidence system at a rate of about 100/year, as well as by the SPI. Hundreds of SGR bursts have been detected from SGR1806-20 by IBIS during Galactic center observations and ToO pointings. I will review some of the highlights of these observations, which include the closest securely identified GRB (z=0.105) after 980425/SN1998bw, and the discovery of a hardness-intensity anticorrelation for SGR bursts. I will also mention some of the more exotic possibilities offered by INTEGRAL, such as the measurement of GRB polarization and the study of quantum gravity using bursts. This work was supported by NASA INTEGRAL Guest Investigator program grants.

  15. Southern analysis of genomic alterations in gamma-ray-induced aprt- hamster cell mutants

    SciTech Connect

    Grosovsky, A.J.; Drobetsky, E.A.; deJong, P.J.; Glickman, B.W.

    1986-06-01

    The role of genomic alterations in mutagenesis induced by ionizing radiation has been the subject of considerable speculation. By Southern blotting analysis we show here that 9 of 55 (approximately 1/6) gamma-ray-induced mutants at the adenine phosphoribosyl transferase (aprt) locus of Chinese hamster ovary (CHO) cells have a detectable genomic rearrangement. These fall into two classes: intragenic deletions and chromosomal rearrangements. In contrast, no major genomic alterations were detected among 67 spontaneous mutants, although two restriction site loss events were observed. Three gamma-ray-induced mutants were found to be intragenic deletions; all may have identical break-points. The remaining six gamma-ray-induced mutants demonstrating a genomic alteration appear to be the result of chromosomal rearrangements, possibly translocation or inversion events. None of the remaining gamma-ray-induced mutants showed any observable alteration in blotting pattern indicating a substantial role for point mutation in gamma-ray-induced mutagenesis at the aprt locus.

  16. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    SciTech Connect

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  17. Gamma bang time analysis at OMEGA

    SciTech Connect

    McEvoy, A. M.; Herrmann, H. W.; Young, C. S.; Mack, J. M.; Kim, Y.; Evans, S.; Sedillo, T.; Horsfield, C. J.; Rubery, M.; Miller, E. K.; Stoeffl, W.; Ali, Z. A.

    2010-10-15

    Absolute bang time measurements with the gas Cherenkov detector (GCD) and gamma reaction history (GRH) diagnostic have been performed to high precision at the OMEGA laser facility at the University of Rochester with bang time values for the two diagnostics agreeing to within 5 ps on average. X-ray timing measurements of laser-target coupling were used to calibrate a facility-generated laser timing fiducial with rms spreads in the measured coupling times of 9 ps for both GCD and GRH. Increased fusion yields at the National Ignition Facility (NIF) will allow for improved measurement precision with the GRH easily exceeding NIF system design requirements.

  18. Covariance Analysis of Gamma Ray Spectra

    SciTech Connect

    Trainham, R.; Tinsley, J.

    2013-01-01

    The covariance method exploits fluctuations in signals to recover information encoded in correlations which are usually lost when signal averaging occurs. In nuclear spectroscopy it can be regarded as a generalization of the coincidence technique. The method can be used to extract signal from uncorrelated noise, to separate overlapping spectral peaks, to identify escape peaks, to reconstruct spectra from Compton continua, and to generate secondary spectral fingerprints. We discuss a few statistical considerations of the covariance method and present experimental examples of its use in gamma spectroscopy.

  19. Covariance analysis of gamma ray spectra

    SciTech Connect

    Trainham, R.; Tinsley, J.

    2013-01-15

    The covariance method exploits fluctuations in signals to recover information encoded in correlations which are usually lost when signal averaging occurs. In nuclear spectroscopy it can be regarded as a generalization of the coincidence technique. The method can be used to extract signal from uncorrelated noise, to separate overlapping spectral peaks, to identify escape peaks, to reconstruct spectra from Compton continua, and to generate secondary spectral fingerprints. We discuss a few statistical considerations of the covariance method and present experimental examples of its use in gamma spectroscopy.

  20. The optimization of gamma spectra processing in prompt gamma neutron activation analysis (PGNAA)

    NASA Astrophysics Data System (ADS)

    Pinault, Jean-Louis; Solis, Jose

    2009-04-01

    The uncertainty of the elemental analysis is one of the major factors governing the utility of on-line Prompt Gamma Neutron Activation Analysis (PGNAA) in the blending and sorting of bulk materials. In this paper, a general method applicable to Gamma spectra processing is presented and applied to PGNAA in mineral industry. Based on the Fourier transform of spectra and their de-correlation in the Fourier space (the improvement of the conditioning of the correlation matrix), processing of overlapping of characteristic peaks minimizes the propagation of random errors, which optimizes the accuracy and decreases the detection limits of elemental analyses. In comparison with classical methods based on the linear combinations of relevant regions of spectra the improvement may be considerable, especially when several elements are interfering. The method is applied to four case stories covering both borehole logging and on-line analysis on conveyor belt of raw materials.

  1. An Overview of the XGAM Code and Related Software for Gamma-ray Analysis

    SciTech Connect

    Younes, W.

    2014-11-13

    The XGAM spectrum-fitting code and associated software were developed specifically to analyze the complex gamma-ray spectra that can result from neutron-induced reactions. The XGAM code is designed to fit a spectrum over the entire available gamma-ray energy range as a single entity, in contrast to the more traditional piecewise approaches. This global-fit philosophy enforces background continuity as well as consistency between local and global behavior throughout the spectrum, and in a natural way. This report presents XGAM and the suite of programs built around it with an emphasis on how they fit into an overall analysis methodology for complex gamma-ray data. An application to the analysis of time-dependent delayed gamma-ray yields from 235U fission is shown in order to showcase the codes and how they interact.

  2. Monte Carlo models and analysis of galactic disk gamma-ray burst distributions

    NASA Technical Reports Server (NTRS)

    Hakkila, Jon

    1989-01-01

    Gamma-ray bursts are transient astronomical phenomena which have no quiescent counterparts in any region of the electromagnetic spectrum. Although temporal and spectral properties indicate that these events are likely energetic, their unknown spatial distribution complicates astrophysical interpretation. Monte Carlo samples of gamma-ray burst sources are created which belong to Galactic disk populations. Spatial analysis techniques are used to compare these samples to the observed distribution. From this, both quantitative and qualitative conclusions are drawn concerning allowed luminosity and spatial distributions of the actual sample. Although the Burst and Transient Source Experiment (BATSE) experiment on Gamma Ray Observatory (GRO) will significantly improve knowledge of the gamma-ray burst source spatial characteristics within only a few months of launch, the analysis techniques described herein will not be superceded. Rather, they may be used with BATSE results to obtain detailed information about both the luminosity and spatial distributions of the sources.

  3. High energy gamma ray results from the second small astronomy satellite

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. F.; Tuemer, T.

    1974-01-01

    A high energy (35 MeV) gamma ray telescope employing a thirty-two level magnetic core spark chamber system was flown on SAS 2. The high energy galactic gamma radiation is observed to dominate over the general diffuse radiation along the entire galactic plane, and when examined in detail, the longitudinal and latitudinal distribution seem generally correlated with galactic structural features, particularly with arm segments. The general high energy gamma radiation from the galactic plane, explained on the basis of its angular distribution and magnitude, probably results primarily from cosmic ray interactions with interstellar matter.

  4. Passive gamma analysis of the boiling-water-reactor assemblies

    NASA Astrophysics Data System (ADS)

    Vo, D.; Favalli, A.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S.; Trellue, H.; Vaccaro, S.

    2016-09-01

    This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden's Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative-Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in the count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: 137Cs, 154Eu, 134Cs, and to a lesser extent, 106Ru and 144Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.

  5. Passive gamma analysis of the boiling-water-reactor assemblies

    DOE PAGESBeta

    Vo, D.; Favalli, A.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S.; Trellue, H.; et al

    2016-06-04

    This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden’s Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative–Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in themore » past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in the count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: 137Cs, 154Eu, 134Cs, and to a lesser extent, 106Ru and 144Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.« less

  6. Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

    NASA Astrophysics Data System (ADS)

    Lopes, F.; Silva, H. G.; Bárias, S.; Barbosa, S. M.

    2015-10-01

    The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon (222Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed.

  7. Wimp searches with gamma rays in the Fermi era: Challenges, methods and results

    SciTech Connect

    Conrad, J.; Cohen-Tanugi, J.

    2015-12-15

    The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments.

  8. Mapping the elemental composition of the moon: Current results of the Lunar Prospector gamma ray spectrometer

    SciTech Connect

    Lawrence, D.J.; Feldman, W.C.; Barraclough, B.L.; Elphic, R.C.; Binder, A.B.; Maurice, S.

    1998-12-01

    One of the instruments on board the recently launched Lunar Prospector spacecraft is a Gamma-Ray Spectrometer (GRS) designed to map the surface elemental composition of the Moon. Specifically, the objectives of the GRS are to map abundances of Fe, Ti, U, Th, K, Si, O and if possible Mg, Al, and Ca. The GRS consists of a bismuth germanate (BGO) crystal placed within a well shaped borated plastic scintillator anti-coincidence (ACS) shield. Events triggering only the BGO are labeled as accepted events; events triggering both the BGO and ACS are labeled as rejected events. BGO spectra for both accepted and rejected events are telemetered to the ground for later analysis. Results of the study are given.

  9. Gamma ray spectrometry of LDEF samples: Results of 1992 analyses

    SciTech Connect

    Winn, W.G.

    1993-09-01

    In January 1990, NASA retrieved the Long Duration Exposure Facility (LDEF), which had orbited the Earth since April 1984. The satellite had become slightly radioactive due to cosmic exposure, and the SRTC Underground Counting Facility was used to analyze LDEF samples of Al and Ta for activations of {sup 22}Na, {sup 172}Lu, and {sup 173}Lu. Background steel trunnion samples, not irradiated in space, were analyzed for {sup 60}Co. This report summarizes results for 15 samples analyzed in 1992.

  10. Use of new spectral analysis methods in gamma spectra deconvolution

    NASA Astrophysics Data System (ADS)

    Pinault, Jean Louis

    1991-07-01

    A general deconvolution method applicable to X and gamma ray spectrometry is proposed. Using new spectral analysis methods, it is applied to an actual case: the accurate on-line analysis of three elements (Ca, Si, Fe) in a cement plant using neutron capture gamma rays. Neutrons are provided by a low activity (5 μg) 252Cf source; the detector is a BGO 3 in. × 8 in. scintillator. The principle of the method rests on the Fourier transform of the spectrum. The search for peaks and determination of peak areas are worked out in the Fourier representation, which enables separation of background and peaks and very efficiently discriminates peaks, or elements represented by several peaks. First the spectrum is transformed so that in the new representation the full width at half maximum (FWHM) is independent of energy. Thus, the spectrum is arranged symmetrically and transformed into the Fourier representation. The latter is multiplied by a function in order to transform original Gaussian into Lorentzian peaks. An autoregressive filter is calculated, leading to a characteristic polynomial whose complex roots represent both the location and the width of each peak, provided that the absolute value is lower than unit. The amplitude of each component (the area of each peak or the sum of areas of peaks characterizing an element) is fitted by the weighted least squares method, taking into account that errors in spectra are independent and follow a Poisson law. Very accurate results are obtained, which would be hard to achieve by other methods. The DECO FORTRAN code has been developed for compatible PC microcomputers. Some features of the code are given.

  11. Gamma-Ray Spectrum Analysis Method for Minicomputers.

    Energy Science and Technology Software Center (ESTSC)

    1984-01-24

    Version 00 SAMPO80 is a rapid and accurate analysis program for gamma-ray spectra measured with Ge(Li) or HPGe detectors. SAMPO80 consists of three separate parts, the shape calibration part SAMPOSHAPE, the peak search and fitting part SAMPOFIT, and the nuclide identification part SAMPOID.

  12. Cowplex usage of the gold gamma - activation analysis information

    SciTech Connect

    Degtyarev, S.I.

    1993-12-31

    A simultaneous gold assay method, evaluation of gold`s grain number and weight, and lithologic type, of ore bearing rock, is described. The basis of this method is gamma activation analysis which permits the assay of 500 grams of gold samples crushed up to 3 mm.

  13. PC/FRAM plutonium isotopic analysis of CdTe gamma-ray spectra

    NASA Astrophysics Data System (ADS)

    Vo, D. T.; Russo, P. A.

    2002-07-01

    This paper reports the results of isotopics measurements of plutonium with the new CdTe gamma-ray spectrometer. These are the first wide-range plutonium gamma-ray isotopics analysis results obtained with other than germanium spectrometers. The CdTe spectrometer measured small plutonium reference samples in reasonable count times, covering the range from low to high burnup. The complete experimental hardware included the new, commercial, portable CdTe detector and two commercial portable multichannel analyzers. Version 4 of FRAM is the software that performed the isotopics analysis.

  14. Terrestrial Gamma-ray Flashes: Twentieth Anniversary and Recent Fermi GBM Results

    NASA Astrophysics Data System (ADS)

    Briggs, Michael

    2014-05-01

    The TGF field has advanced remarkably in the twenty years since the publication of the paper "Discovery of intense gamma-ray flashes of atmospheric origin" by G. J. Fishman et al. I will review the BATSE observations and how the following space-based observations of RHESSI, AGILE and Fermi advanced the field. BATSE discovered TGFs, including multi-pulse ones, and established the correlation of TGFs with thunderstorms. Retrospective analysis of BATSE data identified electron-beam events. RHESSI observations extended the spectra to higher energies and indicated a lower source altitude. The shape of the spectrum measured with AGILE challenges the predictions of the large-scale relativistic runaway electron avalanche (RREA) model. Much progress has been made with the combination of space-based gamma-ray and ground-based radio observations. Finally, I will review Fermi GBM results. The high effective area of GBM enables improved measurements of pulse profiles. Some multi-pulse events have separations as short as 1/4 ms, so that the pulses partially overlap. Short events are typically asymmetric, consistent with a Compton tail, while longer events are commonly symmetric, consistent with the Compton tail being hidden within the longer pulse. GBM also found electron-beam events to include positrons. Recent ground-based search of individual photon data uncovered fainter and shorter TGFs. Radio observations of GBM TGFs and a strong TGF duration / radio-detection anti-correlation show that the radio detections that are very close in time (< tens of microseconds) to a TGF are due to the TGF itself rather than from lightning. Analysis of the first year of continuous individual photon data found more than 800 TGFs.

  15. Analysis of gamma prime shape changes in a single crystal Ni-base superalloy

    NASA Technical Reports Server (NTRS)

    Gayda, J.; Mackay, R. A.

    1989-01-01

    The microstructural evolution of a commercial single crystal superalloy, NASAIR 100, is analyzed using the existing high-temperature lattice mismatch data and high-temperature moduli obtained from tests on single crystals of gamma and gamma prime. A multiparticle analysis of the microstructural evolution is performed using a novel microstructural lattice simulation technique, MCFET. Under a uniaxial stress, a regular array of gamma prime particles in the simulated microstructure is predicted to coalesce and form a plate morphology, with the broad faces of the plates and stress axis perpendicular in tension but parallel in compression. These results are consistent with changes in gamma prime shape observed in NASAIR 100 following creep testing at 1000 C.

  16. Results from GROCSE I: A real-time search for gamma ray burst optical counterparts

    SciTech Connect

    Lee, B.; Akerlof, C.; Ables, E.

    1995-10-27

    The GROCSE I experiment (Gamma-Ray Optical Counterpart Search Experiment) is a rapid slewing wide field of view optical telescope at Lawrence Livermore National Laboratory which responds to triggers from the BATSE GRB data telemetry stream that have been processed and distributed by the BACODINE network. GROCSE 1 has been in continuous automated operation since January 1994. As of October 1995, sky images for 22 GRB triggers have been recorded, in some cases while the burst was still emitting gamma rays. The preliminary analysis of eight of these events are presented here. No optical counterparts have yet been detected. Limits for optical emission are given.

  17. Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) for Elemental Analysis

    SciTech Connect

    Robin P. Gardner

    2006-04-11

    This research project was to improve the prompt gamma-ray neutron activation analysis (PGNAA) measurement approach for bulk analysis, oil well logging, and small sample thermal enutron bean applications.

  18. A de-noising algorithm to improve SNR of segmented gamma scanner for spectrum analysis

    NASA Astrophysics Data System (ADS)

    Li, Huailiang; Tuo, Xianguo; Shi, Rui; Zhang, Jinzhao; Henderson, Mark Julian; Courtois, Jérémie; Yan, Minhao

    2016-05-01

    An improved threshold shift-invariant wavelet transform de-noising algorithm for high-resolution gamma-ray spectroscopy is proposed to optimize the threshold function of wavelet transforms and reduce signal resulting from pseudo-Gibbs artificial fluctuations. This algorithm was applied to a segmented gamma scanning system with large samples in which high continuum levels caused by Compton scattering are routinely encountered. De-noising data from the gamma ray spectrum measured by segmented gamma scanning system with improved, shift-invariant and traditional wavelet transform algorithms were all evaluated. The improved wavelet transform method generated significantly enhanced performance of the figure of merit, the root mean square error, the peak area, and the sample attenuation correction in the segmented gamma scanning system assays. We also found that the gamma energy spectrum can be viewed as a low frequency signal as well as high frequency noise superposition by the spectrum analysis. Moreover, a smoothed spectrum can be appropriate for straightforward automated quantitative analysis.

  19. EGAF: Measurement and Analysis of Gamma-ray Cross Sections

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Abusaleem, K.; Basunia, M. S.; Bečvář, F.; Belgya, T.; Bernstein, L. A.; Choi, H. D.; Escher, J. E.; Genreith, C.; Hurst, A. M.; Krtička, M.; Renne, P. R.; Révay, Zs.; Rogers, A. M.; Rossbach, M.; Siem, S.; Sleaford, B.; Summers, N. C.; Szentmiklosi, L.; van Bibber, K.; Wiedeking, M.

    2014-05-01

    The Evaluated Gamma-ray Activation File (EGAF) is the result of a 2000-2007 IAEA Coordinated Research Project to develop a database of thermal, prompt γ-ray cross sections, σγ, for all elemental and selected radioactive targets. No previous database of this kind had existed. EGAF was originally based on measurements using guided neutron beams from the Budapest Reactor on all elemental targets from Z=1-82, 90 and 92, except for He and Pm. The EGAF σγ data were published in the Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis [1]. An international collaboration has formed to continue the EGAF measurements with isotopically enriched targets, derive total radiative thermal neutron cross sections, σ0, extend the σγ data from thermal to 20 MeV neutrons, compile a completed activation data file, improve sections of the Reference Input Parameter Library (RIPL) with more complete and up to date level and γ-ray data, evaluate statistical γ-ray data from reaction studies, and determine recommended neutron separations energies, Sn, for atomic mass evaluations. A new guided neutron beam facility has become available at the Garching (Munich) FRM II Reactor, and high energy neutron experimental facilities are being developed by a Berkeley area collaboration where 5-33 MeV neutron beams are available at the LBNL 88” cyclotron, 2.5 and 14 MeV beams at the University of California, Berkeley neutron generator laboratory, and high flux, 10 nṡcmṡ-2 s-1, neutron pulses available from the LLNL National Ignition Facility (NIF).

  20. First Results & Future Prospects for 30 GeV Gamma Rays from CELESTE

    NASA Astrophysics Data System (ADS)

    de Naurois, Mathieu

    The CELESTE solar farm gamma-ray telescope detected the Crab Nebula at 80 GeV ( Hz) using 18 heliostats in 1998. In March 1999, observations began with a setup extended to 40 heliostats, and with upgraded electronics. Technical delays and bad weather only permitted a very small data set for the Crab nebula. hours of data were taken simultaneously with the CAT imaging telescope showing evidence for a gamma signal. In this talk the analysis method of these data is described. CELESTE has passed major milestones and the groundwork is laid for the blazar and pulsar studies presented elsewhere in this conference (OG 2.1.20, OG 2.2.31). DEDICATION : CELESTE is the brainchild of Eric Pare, who died at the age of 39 in an automobile accident, two weeks after finding our first gamma ray signal. Eric also played a major role in the conception and design of CAT. We dedicate this work to his memory.

  1. Data analysis of the COMPTEL instrument on the NASA gamma ray observatory

    NASA Technical Reports Server (NTRS)

    Diehl, R.; Bennett, K.; Collmar, W.; Connors, A.; Denherder, J. W.; Hermsen, W.; Lichti, G. G.; Lockwood, J. A.; Macri, J.; Mcconnell, M.

    1992-01-01

    The Compton imaging telescope (COMPTEL) on the Gamma Ray Observatory (GRO) is a wide field of view instrument. The coincidence measurement technique in two scintillation detector layers requires specific analysis methods. Straightforward event projection into the sky is impossible. Therefore, detector events are analyzed in a multi-dimensional dataspace using a gamma ray sky hypothesis convolved with the point spread function of the instrument in this dataspace. Background suppression and analysis techniques have important implications on the gamma ray source results for this background limited telescope. The COMPTEL collaboration applies a software system of analysis utilities, organized around a database management system. The use of this system for the assistance of guest investigators at the various collaboration sites and external sites is foreseen and allows different detail levels of cooperation with the COMPTEL institutes, dependent on the type of data to be studied.

  2. A review of recent results in gamma-ray astronomy obtained from high-altitude balloons

    NASA Astrophysics Data System (ADS)

    Teegarden, B. J.

    1994-06-01

    This paper reviews recent results in gamma-ray astronomy obtained from experiments flown on high-altitude balloons. New generation balloon-borne imaging experiments have produced the first gamma-ray maps of the Galactic center (GC) region. Balloon flights of new gamma-ray spectrometers with improved sensitivity have provided important new information on the GC annihilation line. For the first time, the narrow 511 keV line as been resolved (FWHM approx. = 3 keV). A very interesting spectral feature at approximately 170 keV has been attributed to backscattered annihilation, probably from the vicinity of a compact object. New results from the Compton Gamma-Ray Observatory (CGRO)/OSSE and Granat/SIGMA experiments on the annihilation line, when considered together with the recent balloon results, have added greatly to our knowledge and understanding of the origin and distribution of this emission. Balloon-borne instruments have made important measurements of gamma-ray continuum and line emission from SN 1987A. The GRIS spectrometer unambiguously resolved the 847 and 1238 keV line emission from radioactive Co-56 synthesized during the explosion. This data indicated that simple spherically symmetric and homogeneous models did not provide an adequate description of the expanding SN shell.

  3. A review of recent results in gamma-ray astronomy obtained from high-altitude balloons

    NASA Technical Reports Server (NTRS)

    Teegarden, B. J.

    1994-01-01

    This paper reviews recent results in gamma-ray astronomy obtained from experiments flown on high-altitude balloons. New generation balloon-borne imaging experiments have produced the first gamma-ray maps of the Galactic center (GC) region. Balloon flights of new gamma-ray spectrometers with improved sensitivity have provided important new information on the GC annihilation line. For the first time, the narrow 511 keV line as been resolved (FWHM approx. = 3 keV). A very interesting spectral feature at approximately 170 keV has been attributed to backscattered annihilation, probably from the vicinity of a compact object. New results from the Compton Gamma-Ray Observatory (CGRO)/OSSE and Granat/SIGMA experiments on the annihilation line, when considered together with the recent balloon results, have added greatly to our knowledge and understanding of the origin and distribution of this emission. Balloon-borne instruments have made important measurements of gamma-ray continuum and line emission from SN 1987A. The GRIS spectrometer unambiguously resolved the 847 and 1238 keV line emission from radioactive Co-56 synthesized during the explosion. This data indicated that simple spherically symmetric and homogeneous models did not provide an adequate description of the expanding SN shell.

  4. Computational techniques in gamma-ray skyshine analysis

    SciTech Connect

    George, D.L.

    1988-12-01

    Two computer codes were developed to analyze gamma-ray skyshine, the scattering of gamma photons by air molecules. A review of previous gamma-ray skyshine studies discusses several Monte Carlo codes, programs using a single-scatter model, and the MicroSkyshine program for microcomputers. A benchmark gamma-ray skyshine experiment performed at Kansas State University is also described. A single-scatter numerical model was presented which traces photons from the source to their first scatter, then applies a buildup factor along a direct path from the scattering point to a detector. The FORTRAN code SKY, developed with this model before the present study, was modified to use Gauss quadrature, recent photon attenuation data and a more accurate buildup approximation. The resulting code, SILOGP, computes response from a point photon source on the axis of a silo, with and without concrete shielding over the opening. Another program, WALLGP, was developed using the same model to compute response from a point gamma source behind a perfectly absorbing wall, with and without shielding overhead. 29 refs., 48 figs., 13 tabs.

  5. Support vector machines for prediction and analysis of beta and gamma-turns in proteins.

    PubMed

    Pham, Tho Hoan; Satou, Kenji; Ho, Tu Bao

    2005-04-01

    Tight turns have long been recognized as one of the three important features of proteins, together with alpha-helix and beta-sheet. Tight turns play an important role in globular proteins from both the structural and functional points of view. More than 90% tight turns are beta-turns and most of the rest are gamma-turns. Analysis and prediction of beta-turns and gamma-turns is very useful for design of new molecules such as drugs, pesticides, and antigens. In this paper we investigated two aspects of applying support vector machine (SVM), a promising machine learning method for bioinformatics, to prediction and analysis of beta-turns and gamma-turns. First, we developed two SVM-based methods, called BTSVM and GTSVM, which predict beta-turns and gamma-turns in a protein from its sequence. When compared with other methods, BTSVM has a superior performance and GTSVM is competitive. Second, we used SVMs with a linear kernel to estimate the support of amino acids for the formation of beta-turns and gamma-turns depending on their position in a protein. Our analysis results are more comprehensive and easier to use than the previous results in designing turns in proteins. PMID:15852509

  6. Feasibility study of plutonium isotopic analysis of resin beads by nondestructive gamma-ray spectroscopy

    SciTech Connect

    Li, T.K.

    1985-01-01

    We have initiated a feasibility study on the use of nondestructive low-energy gamma-ray spectroscopy for plutonium isotopic analysis on resin beads. Seven resin bead samples were measured, with each sample containing an average of 9 ..mu..g of plutonium; the isotopic compositions of the samples varied over a wide range. The gamma-ray spectroscopy results, obtained from 4-h counting-time measurements, were compared with mass spectrometry results. The average ratios of gamma-ray spectroscopy to mass spectrometry were 1.014 +- 0.025 for /sup 238/Pu//sup 239/Pu, 0.996 +- 0.018 for /sup 240/Pu//sup 239/Pu, and 0.980 +- 0.038 for /sup 241/Pu//sup 239/Pu. The rapid, automated, and accurate nondestructive isotopic analysis of resin beads may be very useful to process technicians and International Atomic Energy Agency inspectors. 3 refs., 1 fig., 3 tabs.

  7. GammaLib and ctools. A software framework for the analysis of astronomical gamma-ray data

    NASA Astrophysics Data System (ADS)

    Knödlseder, J.; Mayer, M.; Deil, C.; Cayrou, J.-B.; Owen, E.; Kelley-Hoskins, N.; Lu, C.-C.; Buehler, R.; Forest, F.; Louge, T.; Siejkowski, H.; Kosack, K.; Gerard, L.; Schulz, A.; Martin, P.; Sanchez, D.; Ohm, S.; Hassan, T.; Brau-Nogué, S.

    2016-08-01

    The field of gamma-ray astronomy has seen important progress during the last decade, yet to date no common software framework has been developed for the scientific analysis of gamma-ray telescope data. We propose to fill this gap by means of the GammaLib software, a generic library that we have developed to support the analysis of gamma-ray event data. GammaLib was written in C++ and all functionality is available in Python through an extension module. Based on this framework we have developed the ctools software package, a suite of software tools that enables flexible workflows to be built for the analysis of Imaging Air Cherenkov Telescope event data. The ctools are inspired by science analysis software available for existing high-energy astronomy instruments, and they follow the modular ftools model developed by the High Energy Astrophysics Science Archive Research Center. The ctools were written in Python and C++, and can be either used from the command line via shell scripts or directly from Python. In this paper we present the GammaLib and ctools software versions 1.0 that were released at the end of 2015. GammaLib and ctools are ready for the science analysis of Imaging Air Cherenkov Telescope event data, and also support the analysis of Fermi-LAT data and the exploitation of the COMPTEL legacy data archive. We propose using ctools as the science tools software for the Cherenkov Telescope Array Observatory.

  8. Coincidence Prompt Gamma-Ray Neutron Activation Analysis

    SciTech Connect

    R.P. gandner; C.W. Mayo; W.A. Metwally; W. Zhang; W. Guo; A. Shehata

    2002-11-10

    The normal prompt gamma-ray neutron activation analysis for either bulk or small beam samples inherently has a small signal-to-noise (S/N) ratio due primarily to the neutron source being present while the sample signal is being obtained. Coincidence counting offers the possibility of greatly reducing or eliminating the noise generated by the neutron source. The present report presents our results to date on implementing the coincidence counting PGNAA approach. We conclude that coincidence PGNAA yields: (1) a larger signal-to-noise (S/N) ratio, (2) more information (and therefore better accuracy) from essentially the same experiment when sophisticated coincidence electronics are used that can yield singles and coincidences simultaneously, and (3) a reduced (one or two orders of magnitude) signal from essentially the same experiment. In future work we will concentrate on: (1) modifying the existing CEARPGS Monte Carlo code to incorporate coincidence counting, (2) obtaining coincidence schemes for 18 or 20 of the common elements in coal and cement, and (3) optimizing the design of a PGNAA coincidence system for the bulk analysis of coal.

  9. Combined Gamma-Ray Spectrometer and Pulsed Neutron Generator System for In-Situ Planetary Geochemical Analysis

    SciTech Connect

    Starr, R. D.; Evans, L. G.; Parsons, A. M.; Akkurt, Hatice; Floyd, H.; Wraight, P.; Ziegler, W.; Schweitzer, J.

    2007-01-01

    A combined pulsed neutron/gamma-ray system can be used on planetary surfaces to provide valuable geochemical analysis of surface materials to depths of {approx}1 m. We describe experimental results that demonstrate the capabilities of such a system.

  10. New results from FRECOPA analysis

    NASA Technical Reports Server (NTRS)

    Durin, Christian

    1993-01-01

    New results from the ongoing analysis of the FRECOPA's (FREnch COoperative PAssive payload) system hardware are discussed. FRECOPA (AO138) was one of the 57 experiments flown on the LDEF satellite. The experiment was located on the trailing edge (Tray B3) and was exposed to UV radiation (11,100 equivalent sun hours), approximately equal to 34,000 thermal cycles, higher vacuum levels than the leading edge, a low atomic oxygen flux, and minor doses of protons and electrons. Due to LDEF's extended mission (5.8 years), CNES decided to set up a team to analyze the FRECOPA system. Initial results were presented at the First Post-Retrieval Conference, June, 1991. The results obtained since then are summarized.

  11. Analysis of data from the energetic gamma-ray experiment of the Gamma Ray Observatory

    NASA Technical Reports Server (NTRS)

    Kniffen, Donald A.

    1995-01-01

    The work under the Grant has involved continued participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The EGRET team continues to submit IAU Astronomical telegrams and present many papers at scientific meetings. The EGRET Team was also successful on many proposals for the Cycle 4 portion of the mission, including long high galactic latitude studies of the diffuse extragalactic radiation in both the Northern and Southern Galactic Sky. These studies will be used in an effort to establish whether this radiation is truly diffuse or the sum of radiation from unresolved discrete sources such as radio-loud quasars. Data analysis is complete for papers on behalf of the EGRET Team by the author on general sources in the anticenter region of the galaxy, with galactic latitudes from 125 to 220 deg. A paper on this subject is in preparation for publication in the Astrophysical Journal. Another is being prepared on EGRET observations of the COS-B source 2CG135. Work is in progress for a third on the contribution of unresolved pulsars to the galactic diffuse radiations; two other papers are in analysis phase. A number of papers have been published in the last reporting period, and several others are in press currently. A summary of the publications is described.

  12. Image Artifacts Resulting from Gamma-Ray Tracking Algorithms Used with Compton Imagers

    SciTech Connect

    Seifert, Carolyn E.; He, Zhong

    2005-10-01

    For Compton imaging it is necessary to determine the sequence of gamma-ray interactions in a single detector or array of detectors. This can be done by time-of-flight measurements if the interactions are sufficiently far apart. However, in small detectors the time between interactions can be too small to measure, and other means of gamma-ray sequencing must be used. In this work, several popular sequencing algorithms are reviewed for sequences with two observed events and three or more observed events in the detector. These algorithms can result in poor imaging resolution and introduce artifacts in the backprojection images. The effects of gamma-ray tracking algorithms on Compton imaging are explored in the context of the 4π Compton imager built by the University of Michigan.

  13. Final SAS-2 gamma-ray results on sources in the galactic anticenter region

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Lamb, R. C.

    1977-01-01

    Final results are presented for SAS-2 observations of high-energy gamma-rays from the galactic anticenter region. Three main gamma-ray features are shown to characterize this region: a localized source associated with the Crab Nebula and its pulsar, another localized source near galactic coordinates 195 deg, +5 deg, and a general enhancement of the diffuse background 10 to 15 deg south of the galactic plane, which is associated with the Gould Belt. For the Crab, it is found that the radiation is mostly pulsed, the pulsed fraction increases with energy, and the intensity of the radiation in the main and interpulse peaks is approximately the same. The other localized source, provisionally designated as gamma 195+5, is found to have a harder spectrum than the Crab but no obvious radio counterpart; emission from an external galaxy is ruled out.

  14. Preliminary Results from the European Space Agency's COS-B satellite for gamma-ray astronomy

    NASA Technical Reports Server (NTRS)

    Swanenburg, B.

    1976-01-01

    The COS-B satellite carries a single experiment, capable of detecting gamma rays with energies greater than 30 MeV. Its objectives are to study the spatial, energy, and time characteristics of high energy radiation of galactic and extragalactic origin. The capability to search for gamma ray pulsations is enhanced by the inclusion in the payload of a proportional counter sensitive to X-rays of 2-12 Kev. The experiment was calibrated using particle accelerators. The results of these measurements are presented and the performance of the system in orbit is discussed.

  15. Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis

    SciTech Connect

    Firestone, Richard B; Perry, D.L.; English, G.A.; Firestone, R.B.; Leung, K.-N.; Garabedian, G.; Molnar, G.L.; Revay, Zs.

    2008-03-24

    Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed.

  16. Advanced gamma ray balloon experiment ground checkout and data analysis

    NASA Technical Reports Server (NTRS)

    Blackstone, M.

    1976-01-01

    A software programming package to be used in the ground checkout and handling of data from the advanced gamma ray balloon experiment is described. The Operator's Manual permits someone unfamiliar with the inner workings of the software system (called LEO) to operate on the experimental data as it comes from the Pulse Code Modulation interface, converting it to a form for later analysis, and monitoring the program of an experiment. A Programmer's Manual is included.

  17. A compact neutron beam generator system designed for prompt gamma nuclear activation analysis.

    PubMed

    Ghassoun, J; Mostacci, D

    2011-08-01

    In this work a compact system was designed for bulk sample analysis using the technique of PGNAA. The system consists of (252)Cf fission neutron source, a moderator/reflector/filter assembly, and a suitable enclosure to delimit the resulting neutron beam. The moderator/reflector/filter arrangement has been optimised to maximise the thermal neutron component useful for samples analysis with a suitably low level of beam contamination. The neutron beam delivered by this compact system is used to irradiate the sample and the prompt gamma rays produced by neutron reactions within the sample elements are detected by appropriate gamma rays detector. Neutron and gamma rays transport calculations have been performed using the Monte Carlo N-Particle transport code (MCNP5). PMID:21129990

  18. Analysis of Data from the Energetic Gamma-ray Experiment on the Gamma Ray Observatory

    NASA Technical Reports Server (NTRS)

    Kniffen, Donald A.

    1996-01-01

    The work under the Grant has involved participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The Principal Investigator (PI) has been a co-author on a total of 90 papers published in refereed professional journals since the beginning of 1991, plus many other non-refereed publications, and contributed and invited papers at professional meetings and IAU telegrams. On seven of these papers he was the lead author. The EGRET team continues to submit IAU Astronomical telegrams and present many papers at scientific meetings. The effort by the PI has involved working remotely by internet connection on the Goddard Space Flight Center Computers where the EGRET data are archived. Students have monitored instrument performance, performed Viewing Period Analyses and analyzed data remotely. The PI has completed the detailed analysis of over 20 viewing periods to search for point sources and this work has been used in developing the first and second EGRET catalog of sources, published in Supplements to the Astrophysical Journal.

  19. Analysis of data from the energetic gamma-ray experiment on the gamma ray observatory

    NASA Technical Reports Server (NTRS)

    Kniffen, Donald A.

    1993-01-01

    The work under the Grant has involved continued participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The EGRET team was also successful on many proposals for the Phase 3 portion of the mission, including long high galactic latitude studies of the diffuse extragalactic radiation. These studies will be used in a effort to establish whether this radiation is truly diffuse or the sum of radiation from unresolved discrete sources such as radio-loud quasars. The effort involved working remotely by internet connection on the Goddard Space Flight Center Computers where the EGRET data are archived. Students have monitored instrument performance and analyzed data remotely and will continue to do so. The PI has completed the detailed analysis of five viewing periods to search for point sources and this work has been used in developing the first EGRET catalog of sources, soon to be released.

  20. Analysis of Data from the Energetic Gamma-ray Experiment on the Gamma Ray Observatory

    NASA Astrophysics Data System (ADS)

    Kniffen, Donald A.

    1996-08-01

    The work under the Grant has involved participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The Principal Investigator (PI) has been a co-author on a total of 90 papers published in refereed professional journals since the beginning of 1991, plus many other non-refereed publications, and contributed and invited papers at professional meetings and IAU telegrams. On seven of these papers he was the lead author. The EGRET team continues to submit IAU Astronomical telegrams and present many papers at scientific meetings. The effort by the PI has involved working remotely by internet connection on the Goddard Space Flight Center Computers where the EGRET data are archived. Students have monitored instrument performance, performed Viewing Period Analyses and analyzed data remotely. The PI has completed the detailed analysis of over 20 viewing periods to search for point sources and this work has been used in developing the first and second EGRET catalog of sources, published in Supplements to the Astrophysical Journal.

  1. Scintillation gamma spectrometer for analysis of hydraulic fracturing waste products.

    PubMed

    Ying, Leong; O'Connor, Frank; Stolz, John F

    2015-01-01

    Flowback and produced wastewaters from unconventional hydraulic fracturing during oil and gas explorations typically brings to the surface Naturally Occurring Radioactive Materials (NORM), predominantly radioisotopes from the U238 and Th232 decay chains. Traditionally, radiological sampling are performed by sending collected small samples for laboratory tests either by radiochemical analysis or measurements by a high-resolution High-Purity Germanium (HPGe) gamma spectrometer. One of the main isotopes of concern is Ra226 which requires an extended 21-days quantification period to allow for full secular equilibrium to be established for the alpha counting of its progeny daughter Rn222. Field trials of a sodium iodide (NaI) scintillation detector offers a more economic solution for rapid screenings of radiological samples. To achieve the quantification accuracy, this gamma spectrometer must be efficiency calibrated with known standard sources prior to field deployments to analyze the radioactivity concentrations in hydraulic fracturing waste products. PMID:25734826

  2. First Year Results from the Fermi Gamma-Ray Space Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    After one year of survey observations and more than 70 billion triggers, Fermi is revealing an unprecedented view of the high energy gamma-ray sky. The observatory .carries two instruments, the Gamma-ray Burst Monitor (GB, 8 keV - 40 MeV) and the Large Area Telescope (LAT, 20 MeV greater than or equal to 300 GeV), which in combination cover over 7 orders of magnitude in energy for transient phenomena. The LAT provides substantially more sensitivity than previous instruments in this waveband and has opened up the energy window from 10-100 GeV. The first year has produced many important results, from detections of extremely energetic and distant gamma-ray bursts, to monitoring daily variations in emission caused by massive black holes at the cores of galaxies, to identifying a new population of gamma-ray bright pulsars, to measuring the spectrum of diffuse emission from our own. Galaxy and the spectrum of the local cosmic electrons. I'll review highlights from the first year and discuss how the data are answering questions from the past and raising new ones for the future.

  3. Dosimetric comparison of tools for intensity modulated radiation therapy with gamma analysis: a phantom study

    NASA Astrophysics Data System (ADS)

    Akbas, Ugur; Okutan, Murat; Demir, Bayram; Koksal, Canan

    2015-07-01

    Dosimetry of the Intensity Modulated Radiation Therapy (IMRT) is very important because of the complex dose distributions. Diode arrays are the most common and practical measurement tools for clinical usage for IMRT. Phantom selection is critical for QA process. IMRT treatment plans are recalculated for the phantom irradiation in QA. Phantoms are made in different geometrical shapes to measure the doses of different types of irradiation techniques. Comparison of measured and calculated dose distributions for IMRT can be made by using gamma analysis. In this study, 10 head-and-neck IMRT QA plans were created with Varian Eclipse 8.9 treatment planning system. Water equivalent RW3-slab phantoms, Octavius-2 phantom and PTW Seven29 2D-array were used for QA measurements. Gantry, collimator and couch positions set to 00 and QA plans were delivered to RW3 and Octavius phantoms. Then the positions set to original angles and QA plans irradiated again. Measured and calculated fluence maps were evaluated with gamma analysis for different DD and DTA criteria. The effect of different set-up conditions for RW3 and Octavius phantoms in QA plan delivery evaluated by gamma analysis. Results of gamma analysis show that using RW3-slab phantoms with setting parameters to 00 is more appropriate for IMRT QA.

  4. New Statistical Results on the Angular Distribution of Gamma-Ray Bursts

    SciTech Connect

    Balazs, Lajos G.; Horvath, Istvan; Vavrek, Roland

    2008-05-22

    We presented the results of several statistical tests of the randomness in the angular sky-distribution of gamma-ray bursts in BATSE Catalog. Thirteen different tests were presented based on Voronoi tesselation, Minimal spanning tree and Multifractal spectrum for five classes (short1, short2, intermediate, long1, long2) of gamma-ray bursts, separately. The long1 and long2 classes are distributed randomly. The intermediate subclass, in accordance with the earlier results of the authors, is distributed non-randomly. Concerning the short subclass earlier statistical tests also suggested some departure from the random distribution, but not on a high enough confidence level. The new tests presented in this article suggest also non-randomness here.

  5. Highlights of recent results from the VERITAS gamma-ray observatory

    NASA Astrophysics Data System (ADS)

    Fortson, Lucy; VERITAS Collaboration

    2016-05-01

    VERITAS is a major ground-based gamma-ray observatory comprising an array of four 12 meter air Cherenkov telescopes operating at the Fred Lawrence Whipple Observatory near Tucson, Arizona. Data taking has continued from 2007 with a major camera upgrade completed in 2012 resulting in the current sensitivity to very-high-energy (VHE) gamma rays between 85 GeV and 30 TeV. VERITAS has detected 54 sources (half of which have been discoveries) leading to many significant contributions to the field of VHE astronomy. These proceedings highlight some of the more recent VERITAS results from the blazar and galactic observing programs as well as measurements of the cosmic-ray electron spectrum, constraints on dark matter and a follow-up program for astrophysical neutrinos.

  6. Prompt gamma activation analysis: An old technique made new

    SciTech Connect

    English, Jerry; Firestone, Richard; Perry, Dale; Leung, Ka-Ngo; Reijonen, Jani; Garabedian, Glenn; Bandong, Bryan; Molnar, Gabor; Revay, Zsolt

    2002-12-01

    The long list of contributors to the prompt gamma activation analysis (PGAA) project is important because it highlights the broad cast of active PGAA researchers from various facilities and backgrounds. PGAA is basically a simple process in principle that was traditionally difficult in application. It is an old technique that has for years been tied to and associated exclusively with nuclear reactor facilities, which has limited its acceptance as a general, analytical tool for identifying and quantifying elements or, more precisely, isotopes, whether radioactive or nonradioactive. Field use was not a viable option.

  7. Final SAS-2 gamma ray results on sources in the galactic anticenter region

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Lamb, R. C.

    1976-01-01

    Analysis of SAS-2 high energy Gamma ray data from the direction of the galactic anticenter shows that this region is characterized by: a diffuse emission from the galactic plane which has a maximum along b=0 deg and an enhancement toward negative latitudes associated with Gould's Belt, a strong point source in the direction of the Crab nebula, and a second intense localized source near galactic coordinates 195 deg, +5 deg. Gamma ray emission from the Crab source is dominated by a pulsed flux from PSR 0531+21. The total flux above 100MeV is 3.7 + or - 0.8 million/sq cm s. The source near 195 deg, + 5 deg has a flux above 100 MeV of 4.3 + or - 0.9 million/sq cm s. Its spectrum appears flatter than that of the Crab. The diffuse galactic plane emission at negative lattitudes shows a general correlation with the local matter distribution associated with Gould's Belt. The calculated Gamma ray intensity agrees well with the SAS-2 observations.

  8. Online Analysis of {gamma}-ray Sources with H.E.S.S

    SciTech Connect

    Fuessling, M.; Dalton, M.; Kerschhaggl, M.; Schwanke, U.; Jung, I.; Stegmann, C.

    2008-12-24

    Some of the {gamma}-ray sources detected by the H.E.S.S. experiment display irregular, often flare-like emission behaviour. A method to detect these outbursts as fast as possible is highly desirable. At H.E.S.S., first results from an offline analysis of pre-calibrated data can be obtained on-site approximately one hour after run end. We present a development and implementation of online analysis software that performs calibration and analysis of data at the time they are being taken allowing for a fast confirmation of observational results and appropriate reaction by the on-site shift crew.

  9. {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma} and {eta} Prime {yields}{eta}{gamma}{gamma}: A primer analysis

    SciTech Connect

    Escribano, Rafel

    2012-10-23

    The electromagnetic rare decays {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma} and {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma} are analysed for the first time and their predicted branching ratios given. The vector meson exchange dominant contribution is treated using Vector Meson Dominance and the scalar component is estimated by means of the Linear Sigma Model. The agreement between our calculation and the measurement of the related process {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma} is a check of the procedure. Scalar meson effects are seen to be irrelevant for {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma}, while a significant scalar contribution due to the {sigma}(500) resonance seems to emerge in the case of {eta} Prime {yields}{pi}{sup 0}{gamma}{gamma}. Future measurements coming from KLOE-2, Crystal Ball, WASA, and BES-III will elucidate if any of these processes carry an important scalar contribution or they are simply driven by the exchange of vector mesons.

  10. Results of Gamma-Ray Measurements from a Recent Demonstration for Russian Technical Experts

    SciTech Connect

    Luke, S J; Archer, D E; Gosnell, T B; Lochner, R T; Morgan, J F; White, G K; Weitz, R

    2001-06-01

    In August 2001, a group of U.S. technical experts demonstrated an Attribute Measurement System with an Information Barrier (AMSIB) for a delegation of Russian technical experts. The purpose of the demonstration was to show that attributes of a classified plutonium item of potential interest to arms control and nonproliferation transparency regimes could be ascertained without releasing any sensitive information. For this demonstration, both gamma-ray and neutron attributes were determined. We consider only the gamma-ray attributes here. The specific plutonium attributes measured were the isotopic ratio of {sup 240}Pu to {sup 239}Pu, the ''age'' of the plutonium (time elapsed since the most recent chemical purification of the plutonium), and the absence of plutonium oxide in the item's storage container. In this paper, we briefly review the technologies employed for the attribute measurements used in the gamma-ray portion of the demonstration, concentrating on the results of the test measurements of the isotopic and age attributes made on unclassified items.

  11. Apollo 17 mission Report. Supplement 6: Calibration results for gamma ray spectrometer sodium iodide crystal

    NASA Technical Reports Server (NTRS)

    Dyer, C.; Trombka, J. I.

    1975-01-01

    A major difficulty in medium energy gamma-ray remote sensing spectroscopy and astronomy measurements was the high rate of unwanted background resulting from the following major sources: (1) prompt secondary gamma-rays produced by cosmic-ray interactions in satellite materials; (2) direct charged-particle counts; (3) radioactivity induced in the detector materials by cosmic-ray and trapped protons; (4) radioactivity induced in detector materials by the planetary (e.g., earth or moon) albedo neutron flux; (5) radioactivity induced in the detector materials by the interaction of secondary neutrons produced throughout the spacecraft by cosmic-ray and trapped proton interactions; (6) radioactivity induced in spacecraft materials by the mechanisms outlined in 3, 4, and 5; and (7) natural radioactivity in spacecraft and detector materials. The purpose of this experiment was to obtain information on effects 3, 4, and 5, and from this information start developing calculational methods for predicting the background induced in the crystal detector in order to correct the Apollo gamma-ray spectrometer data for this interference.

  12. Monte Carlo Modeling of Cascade Gamma Rays in 86Y PET imaging: Preliminary results

    PubMed Central

    Zhu, Xuping; El Fakhri, Georges

    2011-01-01

    86Y is a PET agent that could be used as an ideal surrogate to allow personalized dosimetry in 90Y radionuclide therapy. However, 86Y also emits cascade gamma rays. We have developed a Monte Carlo program based on SimSET to model cascade gamma rays in PET imaging. The new simulation was validated with the GATE simulation package. Agreements within 15% were found in spatial resolution, apparent scatter fraction (ratio of coincidences outside peak regions in line source sinograms), singles and coincidences statistics and detected photons energy distribution within the PET energy window. A 20% discrepancy was observed in the absolute scatter fraction, likely caused by differences in the tracking of higher-energy cascade gamma photons. On average the new simulation is 6 times faster than GATE, and the computing time can be further improved by using variance reduction techniques currently available in SimSET. Comparison with phantom acquisitions showed agreements in spatial resolutions and the general shape of projection profiles; however, the standard scatter correction method on the scanner is not directly applicable for 86Y PET as it leads to incorrect scatter fractions. The new simulation was used to characterize 86Y PET. Compared with conventional 18F PET, in which major contamination at low count rates comes from scattered events, cascade gamma-involved events are more important in 86Y PET. The two types of contaminations have completely different distribution patterns, which should be considered for the corrections of their effects. Our approach will be further improved in the future in the modeling of random coincidences and tracking of high energy photons, and simulation results will be used for the development of correction methods in 86Y PET. PMID:19521011

  13. Monte Carlo modeling of cascade gamma rays in 86Y PET imaging: preliminary results

    NASA Astrophysics Data System (ADS)

    Zhu, Xuping; El Fakhri, Georges

    2009-07-01

    86Y is a PET agent that could be used as an ideal surrogate to allow personalized dosimetry in 90Y radionuclide therapy. However, 86Y also emits cascade gamma rays. We have developed a Monte Carlo program based on SimSET (Simulation System for Emission Tomography) to model cascade gamma rays in PET imaging. The new simulation was validated with the GATE simulation package. Agreements within 15% were found in spatial resolution, apparent scatter fraction (ratio of coincidences outside peak regions in line source sinograms), single and coincidence statistics and detected photons energy distribution within the PET energy window. A discrepancy of 20% was observed in the absolute scatter fraction, likely caused by differences in the tracking of higher energy cascade gamma photons. On average, the new simulation is 6 times faster than GATE, and the computing time can be further improved by using variance reduction techniques currently available in SimSET. Comparison with phantom acquisitions showed agreements in spatial resolutions and the general shape of projection profiles; however, the standard scatter correction method on the scanner is not directly applicable to 86Y PET as it leads to incorrect scatter fractions. The new simulation was used to characterize 86Y PET. Compared with conventional 18F PET, in which major contamination at low count rates comes from scattered events, cascade gamma-involved events are more important in 86Y PET. The two types of contaminations have completely different distribution patterns, which should be considered for the corrections of their effects. Our approach will be further improved in the future in the modeling of random coincidences and tracking of high-energy photons, and simulation results will be used for the development of correction methods in 86Y PET.

  14. U235: a gamma ray analysis code for uranium isotopic determination

    SciTech Connect

    Clark, D.

    1997-12-01

    A {sup 235}U analysis code, U235, has been written that can nondestructively determine the percentage of {sup 235}U in a uranium sample from the analysis of the emitted gamma rays. The code is operational and work is now underway to improve the accuracy of the calculation, particularly at the high (>90%) and low (<0.7%) {sup 235}U concentrations. A technique has been found to evaluate low {sup 235}U concentrations that works well on the existing standards. Work is now under way to evaluate this technique for other detectors and other types of samples. Work is also proceeding on: (1) ways to better determine gamma backgrounds, (2) techniques to determine the equivalent thickness of the sample to correct for gamma attenuation, (3) evaluation of the existing data base of branching ratios of {sup 235}U, {sup 238}U and their daughters gamma rays to allow better results and (4) evaluation of the existing data base on the emission ratios for uranium, thorium, and protactinium x-rays.

  15. Integral-moment analysis of the BATSE gamma-ray burst intensity distribution

    NASA Technical Reports Server (NTRS)

    Horack, John M.; Emslie, A. Gordon

    1994-01-01

    We have applied the technique of integral-moment analysis to the intensity distribution of the first 260 gamma-ray bursts observed by the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. This technique provides direct measurement of properties such as the mean, variance, and skewness of the convolved luminosity-number density distribution, as well as associated uncertainties. Using this method, one obtains insight into the nature of the source distributions unavailable through computation of traditional single parameters such as V/V(sub max)). If the luminosity function of the gamma-ray bursts is strongly peaked, giving bursts only a narrow range of luminosities, these results are then direct probes of the radial distribution of sources, regardless of whether the bursts are a local phenomenon, are distributed in a galactic halo, or are at cosmological distances. Accordingly, an integral-moment analysis of the intensity distribution of the gamma-ray bursts provides for the most complete analytic description of the source distribution available from the data, and offers the most comprehensive test of the compatibility of a given hypothesized distribution with observation.

  16. APREF Project: Results and Analysis

    NASA Astrophysics Data System (ADS)

    Moore, M. J.; Dawson, J.; Hu, G.

    2010-12-01

    The Asia-Pacific Reference Frame (APREF) Project is a regional initiative that seeks to improve the geodetic infrastructure of the Asia-Pacific region. As a joint effort of the Permanent Committee on GIS Infrastructure for Asia and the Pacific (PCGIAP) and the International Association of Geodesy (IAG), APREF is developing a start-of-the-art regional geodetic reference frame. In the Asia-Pacific region there are a substantial number of state-of-the-art GNSS networks, which are commonly operated by national mapping agencies or private sector organisations. These networks represent an important and significant investment by the respective governments and industry in their own spatial infrastructure. In the APREF initiative these networks are combined to realize a high-standard regional reference frame. The GNSS data of the network is processed by different Analysis Centres (ACs). The contributions of the different ACs are combined into a weekly solution by the APREF Central Bureau. This weekly solution is the core product of the APREF; it contains weekly estimates of the coordinates of the participating Asia-Pacific GNSS tracking stations and their covariance information. The APREF product, which is available since the first quarter of 2010, gives a reliable time-series of a regional reference frame in the International Terrestrial Reference Frame and a quality assessment of the performance of the GNSS CORS stations included in the network. This contribution gives an overview of the current status of the APREF network and an analysis of the first APREF products

  17. Gamma-ray Full Spectrum Analysis for Environmental Radioactivity by HPGe Detector

    NASA Astrophysics Data System (ADS)

    Jeong, Meeyoung; Lee, Kyeong Beom; Kim, Kyeong Ja; Lee, Min-Kie; Han, Ju-Bong

    2014-12-01

    Odyssey, one of the NASA¡¯s Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of 40K, 232Th and 238U in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

  18. Analysis of EUVE Experiment Results

    NASA Technical Reports Server (NTRS)

    Horan, Stephen

    1996-01-01

    A series of tests to validate an antenna pointing concept for spin-stabilized satellites using a data relay satellite are described. These tests show that proper antenna pointing on an inertially-stabilized spacecraft can lead to significant access time through the relay satellite even without active antenna pointing. We summarize the test results, the simulations to model the effects of antenna pattern and space loss, and the expected contact times. We also show how antenna beam width affects the results.

  19. Hardening anisotropy of {gamma}/{gamma}{prime} superalloy single crystals. 2: Numerical analysis of heterogeneity effects

    SciTech Connect

    Estevez, R.; Hoinard, G.; Franciosi, P.

    1997-04-01

    In the first part of this study, the {gamma}/{gamma}{prime} superalloy single crystals yield stress and hardening anisotropy were experimentally estimated at 650 C, assuming homogeneous plasticity, G. Hoinard, R. Estevez and P. Franciosi, Acta Metall. 43, 1593 (1995). Here alloy morphology is regarded in two different ways: first as a two-phase anisotropic material with a uniform {gamma} matrix, describing the {gamma}{prime} precipitates arrangement with the help of an elementary pattern of inclusions; then treating the {gamma} matrix as a three (geometrical) phase medium, i.e., the three families of orthogonal {gamma} layers separating the precipitates, to estimate the matrix behavior heterogeneity in a 4-phase modelling of the alloy. Both {gamma} and {gamma}{prime} phases are treated as elastic-plastic crystalline media deforming by octahedral and cubic slip, and the models are based on the self consistent approximation. The alloy elasticity limit, internal stresses and hardening anisotropy are discussed with regard to the chosen behavior description for each phase, and behavior simulations are compared to experimental information.

  20. Advanced concepts for gamma ray isotopic analysis and instrumentation

    NASA Astrophysics Data System (ADS)

    Buckley, W. M.; Carlson, J. B.

    1994-07-01

    The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing actinide isotopic analysis technologies in response to needs that address issues of flexibility of analysis, robustness of analysis, ease-of-use, automation and portability. Recent developments such as the Intelligent Actinide Analysis System (IAAS), begin to address these issues. We are continuing to develop enhancements on this and other instruments that improve ease-of-use, automation and portability. Requests to analyze samples with unusual isotopics, contamination, or containers have made us aware of the need for more flexible and robust analysis. We have modified the MGA program to extend its plutonium isotopic analysis capability to samples with greater Am-241 content or U isotopics. We are looking at methods for dealing with tantalum or lead contamination and contamination with high-energy gamma emitters, such as U-233. We are looking at ways to allow the program to use additional information about the sample to further extend the domain of analyzable samples. These unusual analyses will come from the domain of samples that need to be measured because of complex reconfiguration or environmental cleanup.

  1. Preliminary Results from a New Analysis Method for EGRET Data

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Bertsch, D. L.; Hunter, S. D.; Deines-Jones, P.; Dingus, B. L.; Kniffen, D. A.; Sreekumar, P.

    1999-01-01

    In order to extend the life of EGRET, the gas in the spark chamber was allowed to deteriorate more than was originally planned for the nominal two year Compton Observatory mission. Gamma ray events are lost because the pattern recognition analysis rules are not optimized for the poorer quality data. By changing the rules used by the data analysts, we can recover a significant fraction of the lost events, allowing improved statistics for detection and study of sources. Preliminary results from the Crab, Geminga, and BL Lacertae indicate the feasibility of this analysis.

  2. Accuracy and stability of positioning in radiosurgery: long-term results of the Gamma Knife system.

    PubMed

    Heck, Bernhard; Jess-Hempen, Anja; Kreiner, Hans Jürg; Schöpgens, Hans; Mack, Andreas

    2007-04-01

    The primary aim of this investigation was to determine the long term overall accuracy of an irradiation position of Gamma Knife systems. The mechanical accuracy of the system as well as the overall accuracy of an irradiation position was examined by irradiating radiosensitive films. To measure the mechanical accuracy, the GafChromic film was fixed by a special tool at the unit center point (UCP). For overall accuracy the film was mounted inside a phantom at a target position given by a two-dimensional cross. Its position was determined by CT or MRI scans, a treatment was planned to hit this target by use of the standard planning software and the radiation was finally delivered. This procedure is named "system test" according to DIN 6875-1 and is equivalent to a treatment simulation. The used GafChromic films were evaluated by high resolution densitometric measurements. The Munich Gamma Knife UCP coincided within x; y; z: -0.014 +/- 0.09 mm; 0.013 +/- 0.09 mm; -0.002 +/- 0.06 mm (mean +/- SD) to the center of dose distribution. There was no trend in the measured data observed over more than ten years. All measured data were within a sphere of 0.2 mm radius. When basing the target definition in the system test on MRI scans, we obtained an overall accuracy of an irradiation position in the x direction of 0.21 +/- 0.32 mm and in the y direction 0.15 +/- 0.26 mm (mean +/- SD). When a CT-based target definition was used, we measured distances in x direction 0.06 +/- 0.09 mm and in y direction 0.04 +/- 0.09 mm (mean +/- SD), respectively. These results were compared with those obtained with a Gamma Knife equipped with an automatic positioning system (APS) by use of a different phantom. This phantom was found to be slightly less accurate due to its mechanical construction and the soft fixation into the frame. The phantom related position deviation was found to be about +/- 0.2 mm, and therefore the measured accuracy of the APS Gamma Knife was evidently less precise by

  3. Gamma self-shielding correction factors calculation for aqueous bulk sample analysis by PGNAA technique.

    PubMed

    Nasrabadi, M N; Mohammadi, A; Jalali, M

    2009-01-01

    In this paper bulk sample prompt gamma neutron activation analysis (BSPGNAA) was applied to aqueous sample analysis using a relative method. For elemental analysis of an unknown bulk sample, gamma self-shielding coefficient was required. Gamma self-shielding coefficient of unknown samples was estimated by an experimental method and also by MCNP code calculation. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the gamma self-shielding within the sample volume is required. PMID:19328700

  4. Results of a comparison study using tomographic and segmented gamma scanner technology

    SciTech Connect

    Hurd, J. R.; Estep, R. J.; Dittrich, S.; Grimes, L. V.; Gomez, C. D.

    2004-01-01

    In order to support the many on-going research and programmatic activities at Los Alamos Plutonium and Chemistry and Metallurgy Research (CMR) Facilities in as accurate, efficient, and cost-effective manner possible, every reasonable effort is made to equip the nondestructive assay (NDA) laboratories with the most modern and technologically advanced instrumentation available. Recently, new state-of-the-art tomographic gamma scanner (TGS) instruments were installed to replace aging and outmoded segmented gamma scanner (SGS) instruments. Through the implementation of a translation axis, in addition to the vertical and rotation axes of the SGS, the TGS technique is able to employ axial tomography to determine the spatial distribution and quantity of nuclear material using high-resolution gamma-ray spectroscopy. Because the attenuation matrix and source distributions are known more accurately than with the SGS technology, biases due to matrix and source distributions should be reduced. In principle, a single calibration should suffice for the determination of isotopic mass for a wide range of material and matrix types. A number of questions naturally arise concerning these purported advantages of the TGS. Perhaps the most fundamental of these is to understand how the TGS measurement results compare with those of a typical SGS on the same well-characterized standards differing in matrix and material type. To that end, the TGS operating parameters were optimized to assay 55-gallon drum waste identical to that measured by our SGS. The calibration and measurement results on these standards, placed in typical low-density waste matrices, are presented and discussed. These results should enable more confident use of the TGS as well as point the way toward even more studies to enable more effective employment of the new TGS technology.

  5. Preliminary Results of the Analysis

    NASA Technical Reports Server (NTRS)

    Pap, Judit

    1995-01-01

    The preliminary results of the photometry of CaII K spectroheliograms taken at the NationalSolar Observatory at Sacramento peak are presented in this paper. We have digitizedspectroheliograms for 1980 (maximum of SC21), 1985 (minimum of SC21), 1987 (beginning of theascending phase of SC22), 1988 and 1989 (ascending phase and maximum of SC22), and 1992(declining phase of SC22). We have analyzed images for 1992 and separated the plages, the magneticnetwork, internetwork elements and the chromospheric background using histogram method. Wehave derived the intensity and area of these features as well as the full disk intensity (Spatial KIndex). The Spatial K Index has been compared to the spectral Ca K index derived from the lineprofiles and total solar and UV irradiance measured by the UARS and NOAA9 satellites. Thecontribution of plages, the magnetic network and internetwork element to the changes observed intotal solar and UV irradiances are also estimated.

  6. Stabilization of prompt gamma-ray neutron activation analysis (PGNAA) spectra from NaI detectors

    NASA Astrophysics Data System (ADS)

    Metwally, W. A.; Gardner, R. P.

    2004-06-01

    NaI detectors are still used frequently in industrial Prompt Gamma-Ray Neutron Activation Analysis applications such as in bulk material analysis. They have the advantages of being efficient for high-energy gamma rays, being relatively rugged, and being able to be used without cooling. When using NaI detectors, and consequently photomultiplier tubes, the quality of the data can drastically deteriorate through gain and zero shifts that result in spectral smearing due to temperature and/or counting rate changes. A new offline approach is presented to stabilize the NaI spectral drift. The approach is not sensitive to the cause of the drift and takes into account the NaI and ADC non-linearities. Peak resolution is improved substantially when this approach is used in the presence of spectral drift.

  7. Preliminary Results of Indoor Radon/thoron Concentrations and Terrestrial Gamma Doses in Gejiu, Yunnan, China

    NASA Astrophysics Data System (ADS)

    Ishikawa, Tetsuo; Tokonami, Shinji; Sun, Quafu; Kobayashi, Yosuke; Min, Xiangdong; Yoshinaga, Shinji

    2008-08-01

    A preliminary survey on indoor radon/thoron and external gamma ray dose rate was conducted for houses in Gejiu city and its neighboring village in Yunnan Province, China. As a result of the radon/thoron measurements for about 50 houses, very high thoron concentrations were found in some hoses (maximum: 7,900 Bq/m3). The mean annual dose from thoron decay products was estimated to be larger than that from radon decay products (2.9 mSv vs. 1.6 mSv). Further dosimetric and epidemiological studies are needed to investigate the possible effects of radon and thoron.

  8. Preliminary Results of Indoor Radon/thoron Concentrations and Terrestrial Gamma Doses in Gejiu, Yunnan, China

    SciTech Connect

    Ishikawa, Tetsuo; Tokonami, Shinji; Kobayashi, Yosuke; Yoshinaga, Shinji; Sun Quafu; Min Xiangdong

    2008-08-07

    A preliminary survey on indoor radon/thoron and external gamma ray dose rate was conducted for houses in Gejiu city and its neighboring village in Yunnan Province, China. As a result of the radon/thoron measurements for about 50 houses, very high thoron concentrations were found in some hoses (maximum: 7,900 Bq/m{sup 3}). The mean annual dose from thoron decay products was estimated to be larger than that from radon decay products (2.9 mSv vs. 1.6 mSv). Further dosimetric and epidemiological studies are needed to investigate the possible effects of radon and thoron.

  9. Natural Gamma Emitters after a Selective Chemical Separation of a TENORM residue: Preliminary Results

    SciTech Connect

    Alves de Freitas, Antonio; Abrao, Alcidio; Godoy dos Santos, Adir Janete; Pecequilo, Brigitte Roxana Soreanu

    2008-08-07

    An analytical procedure was established in order to obtain selective fractions containing radium isotopes ({sup 228}Ra), thorium ({sup 232}Th), and rare earths from RETOTER (REsiduo de TOrio e TErras Raras), a solid residue rich in rare earth elements, thorium isotopes and small amount of natural uranium generated from the operation of a thorium pilot plant for purification and production of pure thorium nitrate at IPEN -CNEN/SP. The paper presents preliminary results of {sup 228}Ra, {sup 226}Ra, {sup 238}U, {sup 210}Pb, and {sup 40}K concentrations in the selective fractions and total residue determined by high-resolution gamma spectroscopy, considering radioactive equilibrium of the samples.

  10. Results of PLACES data analysis

    NASA Astrophysics Data System (ADS)

    Prettie, C. W.

    1982-09-01

    The results of analyses performed to support PLACES data reduction and data interpretation are presented. Beacon receiver measurements of the scattering of a 100 MHz pseudo-noise beacon signal BPSK modulated at a 10 MHz rate were made during an occulatation by the structured IRIS ion cloud. The scattering produced features in the received St. George Island signal that are shown to be in good quantitative agreement with propagation effect predictions produced from an optically derived model of the ion cloud extent. The features in the received data are also in qualitative agreement with the optical features in a coincident St. George Island photograph. Neutral wind shear rate is determined in the optical analyses to be directed with a 351 deg azimuth with a 1.5 meter per second per kilometer of altitude magnitude. Aircraft propagation measurements of the JAN ion cloud reveal a steady decay of the TEC until the cloud effects vanish at roughly 200 minutes after release. The following mechanism is proposed to explain late time barium cloud decay: Barium ions are removed from the ion cloud as current carriers and are replaced by molecular air ions which quickly recombine. The mechanism is found to be highly efficient. The kHz frequency spurs in the NRL density probe data from JAN are briefly investigated. The spur frequency is found to have no clear-cut dependence on local density, is not confined to the ion cloud region, and at times two spurs are visible in the data.

  11. Correlation Analysis of Prompt Emission from Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Pothapragada, Sriharsha

    Prompt emission from gamma-ray bursts (GRBs) exhibits very rapid, complicated temporal and spectral evolution. This diverse variability in the light-curves reflects the complicated nature of the underlying physics, in which inter-penetrating relativistic shells in the outflow are believed to generate strong magnetic fields that vary over very small scales. We use the theory of jitter radiation to model the emission from such regions and the resulting overall prompt gamma ray emission from a series of relativistic collisionless shocks. We present simulated GRB light-curves developed as a series of "pulses" corresponding to instantaneously illuminated "thin-shell" regions emitting via the jitter radiation mechanism. The effects of various geometries, viewing angles, and bulk Lorentz factor profiles of the radiating outflow jets on the spectral features and evolution of these light-curves are explored. Our results demonstrate how an anisotropic jitter radiation pattern, in conjunction with relativistic shock kinematics, can produce certain features observed in the GRB prompt emission spectra, such as the occurrence of hard, synchrotron violating spectra, the "tracking" of observed flux with spectral parameters, and spectral softening below peak energy within individual episodes of the light curve. We highlight predictions in the light of recent advances in the observational sphere of GRBs.

  12. Transitions, cross sections and neutron binding energy in 186Re by Prompt Gamma Activation Analysis

    NASA Astrophysics Data System (ADS)

    Lerch, A. G.; Hurst, A. M.; Firestone, R. B.; Revay, Zs.; Szentmiklosi, L.; McHale, S. R.; McClory, J. W.; Detwiler, B.; Carroll, J. J.

    2014-03-01

    The nuclide 186Re possesses an isomer with 200,000 year half-life while its ground state has a half-life of 3.718 days. It is also odd-odd and well-deformed nucleus, so should exhibit a variety of other interesting nuclear-structure phenomena. However, the available nuclear data is rather sparse; for example, the energy of the isomer is only known to within + 7 keV and, with the exception of the J?=1- ground state, every proposed level is tentative in the ENSDF. Previously, Prompt Gamma Activation Analysis (PGAA) was utilized to study natRe with 186,188Re being produced via thermal neutron capture. Recently, an enriched 185Re target was irradiated by thermal neutrons at the Budapest Research Reactor to build on those results. Prompt (primary and secondary) and delayed gamma-ray transitions were measured with a large-volume, Compton-suppressed HPGe detector. Absolute cross sections for each gamma transition were deduced and corrected for self attenuation within the sample. Fifty-two primary gamma-ray transitions were newly identified and used to determine a revised value of the neutron binding energy. DICEBOX was used to simulate the decay scheme and the total radiative thermal neutron capture cross section was found to be 97+/-3 b Supported by DTRA (Detwiler) through HDTRA1-08-1-0014.

  13. Results from the first year of the HAWC Gamma Ray Observatory

    NASA Astrophysics Data System (ADS)

    Goodman, Jordan

    2016-07-01

    The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory in the high mountains of Mexico was completed in March of 2015 and is now giving us a new view of the TeV sky. HAWC is 15 times more sensitive than the previous generation of wide-field EAS gamma-ray instruments and is able to detect the Crab nebula at >6 σ with each daily transit. In our first year of operation, HAWC has a 5σ detection sensitivity for a source of ~50mCrab. Unlike Imaging Atmospheric Cherenkov Telescopes (IACTs), HAWC operates 24hrs/day with over a 95% on-time and observes the entire overhead sky (~2sr). HAWC's peak energy sensitivity is 2-10 TeV which is ~10x higher than IACTs such as VERITAS and HESS, which makes their observations quite complementary. This talk will present results from the first year of HAWC data including our study of the galactic plane including new sources not yet detected by IACTs as well as spectra and morphology of bright sources. In addition, results of our monitoring of transient AGN will be presented.

  14. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    SciTech Connect

    Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh��user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K��ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

    2014-08-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  15. Multi-shot analysis of the gamma reaction history diagnostic

    SciTech Connect

    Sayre, D. B.; Bernstein, L. A.; Church, J. A.; Stoeffl, W.; Herrmann, H. W.

    2012-10-15

    The gamma reaction history diagnostic at the National Ignition Facility has the capability to determine a number of important performance metrics for cryogenic deuterium-tritium implosions: the fusion burn width, bang time and yield, as well as the areal density of the compressed ablator. Extracting those values from the measured {gamma} rays of an implosion, requires accounting for a {gamma}-ray background in addition to the impulse response function of the instrument. To address these complications, we have constructed a model of the {gamma}-ray signal, and are developing a simultaneous multi-shot fitting routine to constrain its parameter space.

  16. PSR J0007+7303 in the CTA1 SNR: New Gamma-ray Results from Two Years of Fermi-LAT Observations

    NASA Technical Reports Server (NTRS)

    Abdo, A. A.; Wood, K. S.; DeCesar, M. E.; Gargano, F.; Giordano, F.; Ray, P. S.; Parent, D.; Harding, A. K.; Miller, M. Coleman; Wood, D. L.; Wolff, M. T.

    2011-01-01

    One of the main results of the Fermi Gamma-Ray Space Telescope is the discovery of gamma-ray selected pulsars. The high magnetic field pulsar, PSR J0007+7303 in CTA1, was the first ever to be discovered through its gamma-ray pulsations. Based on analysis of 2 years of LAT survey data, we report on the discovery of I-ray emission in the off-pulse phase interval at the approx. 6sigma level. The flux from this emission in the energy range E > or =::: 100 MeV is F(sub 100) = (1.73+/-0.40) x 10(exp -8) photons/sq cm/s and is best fitted by a power law with a photon index of Gamma = 2.54+/-0.14. The pulsed gamma-ray flux in the same energy range is F(sub 100) = (3.95+/-0.07) x 10(exp -7) photons/sq cm/s and is best fitted by an exponentially-cutoff power-law spectrum with a photon index of Gamma = 1.41+/-0.23 and a cutoff energy E(sub c) = 4.04+/-0.20 GeV. We find no flux variability neither at the 2009 May glitch nor in the long term behavior. We model the gamma-ray light curve with two high-altitude emission models, the outer gap and slot gap, and find that the model that best fits the data depends strongly on the assumed origin of the off-pulse emission. Both models favor a large angle between the magnetic axis and observer line of sight, consistent with the nondetection of radio emission being a geometrical effect. Finally we discuss how the LAT results bear on the understanding of the cooling of this neutron star.

  17. A mass spectroscopic analysis of {gamma}-GPS films

    SciTech Connect

    Dillingham, R.G.; Boerio, F.J.; Bertelsen, C.; Savina, M.R.; Lykke, K.; Calaway, W.

    1996-12-31

    Preparation of substrates for painting or adhesive bonding frequently includes roughening through sanding, chemical etching, or gritblasting. Increased roughness can improve interfacial strength and durability due to increased mechanical interlocking, increased surface area, and improved wettability of the substrate. The chemical reactivity of the surface with the organic phase may be affected as well, perhaps related to the strain energy stored in the surface regions through the intense plastic deformation that occurs. Unfortunately, the chemistry of interactions taking place near a surface that has been roughened is difficult to access analytically by some of the more useful techniques such as infrared spectroscopy. This paper discusses analysis of nonreflective grit-blasted surfaces using mass spectroscopy of species which were either sputtered off using an ion beam (Static Secondary Ion Mass Spectroscopy, or SSIMS) or thermally desorbed as neutrals using a pulsed laser and then post-ionized using a secondary laser (Laser Desorption-Laser Ionization Mass Spectroscopy, or LDLIMS). Both of these techniques exhibit sub-nanometer sensitivity and provide significant information as to the chemistry and structure of the surface regions. In a current application of {gamma}-glycidoxypropyltrimethoxysilane ({gamma}-GPS) for the pre-treatment of grit-blasted aluminum before adhesive bonding, certain factors related to the handling of the primer solution and to the application technique were found to significantly affect the performance of the adhesive bond under long-term aging conditions including stress and humidity. To understand why these parameters are important and to potentially improve the pretreatment process even further, the authors have been investigating how the structure and reactivity of these silane films are related to the application techniques.

  18. A revised analysis of gamma-ray bursts' prompt efficiencies

    NASA Astrophysics Data System (ADS)

    Beniamini, Paz; Nava, Lara; Piran, Tsvi

    2016-09-01

    The prompt gamma-ray bursts' (GRBs) efficiency is an important clue on the emission mechanism producing the γ-rays. Previous estimates of the kinetic energy of the blast waves, based on the X-ray afterglow luminosity LX, suggested that this efficiency is large, with values above 90 per cent in some cases. This poses a problem to emission mechanisms and in particular to the internal shocks model. These estimates are based, however, on the assumption that the X-ray emitting electrons are fast cooling and that their Inverse Compton (IC) losses are negligible. The observed correlations between LX (and hence the blast wave energy) and Eγ, iso, the isotropic equivalent energy in the prompt emission, has been considered as observational evidence supporting this analysis. It is reasonable that the prompt gamma-ray energy and the blast wave kinetic energy are correlated and the observed correlation corroborates, therefore, the notion LX is indeed a valid proxy for the latter. Recent findings suggest that the magnetic field in the afterglow shocks is significantly weaker than was earlier thought and its equipartition fraction, ɛB, could be as low as 10-4 or even lower. Motivated by these findings we reconsider the problem, taking now IC cooling into account. We find that the observed LX - Eγ, iso correlation is recovered also when IC losses are significant. For small ɛB values the blast wave must be more energetic and we find that the corresponding prompt efficiency is significantly smaller than previously thought. For example, for ɛB ˜ 10-4 we infer a typical prompt efficiency of ˜15 per cent.

  19. A Revised Analysis of Gamma Ray Bursts' prompt efficiencies

    NASA Astrophysics Data System (ADS)

    Beniamini, Paz; Nava, Lara; Piran, Tsvi

    2016-06-01

    The prompt Gamma-Ray Bursts' (GRBs) efficiency is an important clue on the emission mechanism producing the γ-rays. Previous estimates of the kinetic energy of the blast waves, based on the X-ray afterglow luminosity LX, suggested that this efficiency is large, with values above 90% in some cases. This poses a problem to emission mechanisms and in particular to the internal shocks model. These estimates are based, however, on the assumption that the X-ray emitting electrons are fast cooling and that their Inverse Compton (IC) losses are negligible. The observed correlations between LX (and hence the blast wave energy) and E_{γ ,iso}, the isotropic equivalent energy in the prompt emission, has been considered as observational evidence supporting this analysis. It is reasonable that the prompt gamma-ray energy and the blast wave kinetic energy are correlated and the observed correlation corroborates, therefore, the notion LX is indeed a valid proxy for the latter. Recent findings suggest that the magnetic field in the afterglow shocks is significantly weaker than was earlier thought and its equipartition fraction, ɛB, could be as low as 10-4 or even lower. Motivated by these findings we reconsider the problem, taking now IC cooling into account. We find that the observed L_X-E_{γ ,iso} correlation is recovered also when IC losses are significant. For small ɛB values the blast wave must be more energetic and we find that the corresponding prompt efficiency is significantly smaller than previously thought. For example, for ɛB ˜ 10-4 we infer a typical prompt efficiency of ˜15%.

  20. In situ capture gamma-ray analysis of coal in an oversize borehole

    USGS Publications Warehouse

    Mikesell, J.L.; Dotson, D.W.; Senftle, F.E.; Zych, R.S.; Koger, J.; Goldman, L.

    1983-01-01

    In situ capture gamma-ray analysis in a coal seam using a high resolution gamma-ray spectrometer in a close-fitting borehole has been reported previously. In order to check the accuracy of the method under adverse conditions, similar measurements were made by means of a small-diameter sonde in an oversize borehole in the Pittsburgh seam, Greene County, Pennsylvania. The hole was 5 times the diameter of the sonde, a ratio that substantially increased the contribution of water (hydrogen) to the total spectral count and reduced the size of the sample measured by the detector. The total natural count, the 40K,count, and the intensities of capture gamma rays from Si, Ca, H, and Al were determined as a function of depth above, through, and below the coal seam. From these logs, the depth and width of the coal seam and its partings were determined. Spectra were accumulated in the seam for 1 h periods by using neutron sources of different strengths. From the spectra obtained by means of several 252Cf neutron sources of different sizes, the ultimate elemental analysis and ash content were determined. The results were not as good as those obtained previously in a close-fitting borehole. However, the results did improve with successively larger source-to-detector distances, i.e.,as the count contribution due to hydrogen in the water decreased. It was concluded that in situ borehole analyses should be made in relatively close-fitting boreholes. ?? 1983.

  1. Airborne gamma radiation measurements of soil moisture during FIFE: Activities and results

    NASA Technical Reports Server (NTRS)

    Peck, Eugene L.

    1992-01-01

    Soil moisture measurements were obtained during the summer of 1987 and 1989 near Manhattan, Kansas, using the National Weather Service (NWS) airborne gamma radiation system. A network of 24 flight lines were established over the research area. Airborne surveys were flown daily during two intensive field campaigns. The data collected was sufficient to modify the NWS standard operational method for estimating soil moisture for the Field Experiment (FIFE) flight lines. The average root mean square error of the soil moisture estimates for shorter FIFE flight lines was found to be 2.5 percent, compared with a reported value of 3.9 percent for NWS flight lines. Techniques were developed to compute soil moisture estimates for portions of the flight lines. Results of comparisons of the airborne gamma radiation soil moisture estimates with those obtained using the NASA Pushbroom Microwave Radiation (PBMR) system and hydrological model are presented. The airborne soil moisture measurements, and real averages computed using all remotely sensed and ground data, have been in support of the research of the many FIFE investigators whose overall goal was the upscale integration of models and the application of satellite remote sensing.

  2. Analysis of Br(anti-B ---> X(s gamma)) at NNLO with a cut on photon energy

    SciTech Connect

    Becher, Thomas; Neubert, Matthias; /Cornell U., LEPP /Mainz U., Inst. Phys.

    2006-10-01

    By combining a recent estimate of the total {bar B} {yields} X{sub s}{gamma} branching fraction at O({alpha}{sub s}{sup 2}) with a detailed analysis of the effects of a cut E{sub {gamma}} {ge} 1.6 GeV on photon energy, a prediction for the partial {bar B} {yields} X{sub s}{gamma} branching fraction at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained, in which contributions from all relevant scales are properly factorized. The result Br({bar B} {yields} X{sub s}{gamma}) = (2.98 {+-} 0.26) {center_dot} 10{sup -4} is about 1.4{sigma} lower than the experimental world average. This opens a window for significant New Physics contributions in rare radiative B decays.

  3. In-situ gamma-analysis support for Phase I, Middlesex cleanup project, Middlesex, New Jersey

    SciTech Connect

    Reiman, R.T.

    1983-07-01

    At the request of the Department of Energy, the Energy Measurements Group of EG and G participated in the Remedial Action program for the former Middlesex Sampling Plant and associated properties at Middlesex, New Jersey from July to November 1980. EG and G provided real time analysis of the radiological character of the soil of each property included in the Phase I cleanup before, during, and after decontamination. The method used for the analysis was in situ gamma spectroscopy employing a high purity germanium detector. This report describes the in situ system and displays the results of the in situ measurements before and after decontamination of the properties surveyed during Phase I.

  4. FociCounter: a freely available PC programme for quantitative and qualitative analysis of gamma-H2AX foci.

    PubMed

    Jucha, Anna; Wegierek-Ciuk, Aneta; Koza, Zbigniew; Lisowska, Halina; Wojcik, Andrzej; Wojewodzka, Maria; Lankoff, Anna

    2010-02-01

    Gamma-H2AX foci are sensitive and specific indicator for the induction of DNA double-strand breaks (DSBs) and an immunocytochemical assay with antibodies recognizing gamma-H2AX has become the gold standard for the detection of this type of DNA lesion. Quantification of gamma-H2AX foci can be achieved by various methods such as Western blotting, flow cytometry, visual analysis and computational analysis with a fluorescence microscope. The best sensitivity is achieved by computer analysis. Since no freeware programme for the analysis of gamma-H2AX foci exists for a PC platform, the aim of our study was to develop a simple and user-friendly public-domain software. The algorithm applied in our programme allows determination of the number of foci in a single cell, a focus intensity per cell, as well as a cell intensity. Its graphical user interface is based on a GTK+ library and the whole application can be run under a variety of operating systems, including MS Windows and Linux. The programme called FociCounter is publicly available at http://focicounter.sourceforge.net. Application of the programme was tested by analysing gamma-H2AX foci in CHO and MO59K cells irradiated in vitro with X-rays and validated by comparing the results obtained with the outcome of automated image analysis and flow cytometry. PMID:20018253

  5. New Mexico Play Fairway Analysis: Gamma Ray Logs and Heat Generation Calculations for SW New Mexico

    DOE Data Explorer

    Shari Kelley

    2015-10-23

    For the New Mexico Play fairway Analysis project, gamma ray geophysical well logs from oil wells penetrating the Proterozoic basement in southwestern New Mexico were digitized. Only the portion of the log in the basement was digitized. The gamma ray logs are converted to heat production using the equation (Bucker and Rybach, 1996) : A[µW/m3] = 0.0158 (Gamma Ray [API] – 0.8).

  6. SAS-2 gamma-ray results from the galactic plane and their implications for galactic structure and galactic cosmic-ray dynamics

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Kniffen, D. A.; Thompson, D. J.

    1977-01-01

    The final SAS-2 results related to high energy galactic gamma-ray emission show a strong correlation with galactic structural features seen at other wavelenghts, when the known gamma-ray sources are subtracted. Theoretical considerations and analysis of the gamma-ray data suggest that the galactic cosmic rays are dynamically coupled to the interstellar matter through the magnetic fields, and hence the cosmic ray density is enhanced where the matter density is greatest on the scale of the galactic arms. This concept has been explored in a galactic model that assumes: (1) cosmic rays are galactic and not universal; (2)on the scale of the galactic arms, the cosmic ray column (surface) density is proportional to the total interstellar gas column density; (3)the cosmic ray scale height is significantly larger than the scale height to the matter; and (4) ours is a spiral galaxy characterized by an arm to interarm density ratio of over 2:1.

  7. Radiative-neutron-capture gamma-ray analysis by a linear combination technique

    USGS Publications Warehouse

    Tanner, A.B.; Bhargava, R.C.; Senftle, F.E.; Brinkerhoff, J.M.

    1972-01-01

    The linear combination technique, when applied to a gamma-ray spectrum, gives a single number indicative of the extent to which the spectral lines of a sought element are present in a complex spectrum. Spectra are taken of the sought element and of various other substances whose spectra interfere with that of the sought element. A weighting function is then computed for application to spectra of unknown materials. The technique was used to determine calcium by radiative-neutron-capture gamma-ray analysis in the presence of interfering elements, notably titanium, and the results were compared with those for two popular methods of peak area integration. Although linearity of response was similar for the methods, the linear combination technique was much better at rejecting interferences. For analyses involving mixtures of unknown composition the technique consequently offers improved sensitivity. ?? 1972.

  8. Results of the gamma-neutron mapper performance test on 55-gallon drums at the RWMC

    SciTech Connect

    Gehrke, R.J.; Lawrence, R.S.; Roybal, L.G.; Svoboda, J.M.; Harker, D.J.; Thompson, D.N.; Carpenter, M.V.; Josten, N.E.

    1995-07-01

    The primary purpose of the gamma-neutron mapper (G@) is to provide accurate and quantitative spatial information of the gamma-ray and neutron radiation fields as a function of position about the excavation of a radioactive waste site. The GNM is designed to operate remotely and can be delivered to any point on an excavation by the robotic gantry crane developed by the dig-face project at the Idaho National Engineering Laboratory (INEL). It can also be easily adapted to other delivery systems. The GNM can be deployed over a waste site at a predetermined scan rate and has sufficient accuracy to identify and quantify radioactive contaminants of importance. The results reported herein are from a performance test conducted at the Transuranic Storage Area, Building 628, of the Radioactive Waste Management Complex located at the INEL. This building is an active interim-storage area for 55-gal drums of transuranic waste from the Department of Energy`s Rocky Flats Plant. The performance test consisted of scanning a stack of drums five high by five wide. Prior to the test, radiation fields were measured by a health physicist at the center of the drums and ranged from 0.5 mR/h to 35 mR/h. Scans of the drums using the GNM were taken at standoff distances from the vertical drum stack of 15 cm, 30 cm, 45 cm, and 90 cm. Data were acquired at scan speeds of 7.5 cm/s and 15 cm/s. The results of these scans and a comparison of these results with the manifests of these drums are compared and discussed.

  9. Leksell Gamma Knife treatment for pilocytic astrocytomas: long-term results.

    PubMed

    Simonova, Gabriela; Kozubikova, Petra; Liscak, Roman; Novotny, Josef

    2016-07-01

    OBJECTIVE The purpose of this study was to evaluate long-term treatment results, radiation-related toxicity, and prognostic factors for the progression-free survival (PFS) of patients with pilocytic astrocytomas treated by means of stereotactic radiosurgery with a Leksell Gamma Knife. METHODS A total of 25 patients with pilocytic astrocytomas underwent Gamma Knife surgery during the period 1992-2002. The median target volume was 2700 mm(3) (range 205-25,000 mm(3)). The 18 patients treated with 5 daily fractions received a median minimum target dose of 25 Gy. Doses for the 2 patients treated with 10 fractions over 5 days (2 fractions delivered on the same day at least 6 hours apart) were 23 and 28 Gy. For the 5 patients treated with a single fraction, the minimum target dose ranged from 13 to 20 Gy (median 16 Gy). RESULTS Complete regression occurred in 10 patients (40%) and partial regression in 10 patients (40%). The 10-year overall survival rate was 96% and the 10-year PFS rate was 80%. Target volume appeared to be a significant prognostic factor for PFS (p = 0.037). Temporary Grade 3 toxicity appeared in 2 patients (8%), and these patients were treated with corticosteroids for 2 months. Permanent Grade 4 toxicity appeared in 2 patients (8%) and was associated with neurocognitive dysfunction. In these 2 individuals, the neurocognitive dysfunction was also felt to be in part the result of the additional therapeutic interventions (4 in one case and 6 in the other) required to achieve durable control of their tumors. CONCLUSIONS Radiosurgery represents an alternative treatment modality for small residual or recurrent volumes of pilocytic astrocytomas and provides long-term local control. Target volume appears to be the most important factor affecting PFS. PMID:26991883

  10. Timing and Fermi LAT Analysis of Four Millisecond Pulsars Discovered in Parkes Radio Searches of Gamma-ray Sources

    NASA Astrophysics Data System (ADS)

    Ray, Paul S.; Ransom, Scott M.; Camilo, Fernando M.; Kerr, Matthew; Reynolds, John; Sarkissian, John; Freire, Paulo; Thankful Cromartie, H.; Barr, Ewan D.

    2016-01-01

    We present phase-connected timing solutions for four binary millisecond pulsars discovered in searches of Fermi LAT gamma-ray sources using the Parkes radio telescope. Follow-up timing observations of PSRs J0955-6150, J1012-4235, J1036-8317, and J1946-5403 have yielded timing models with precise orbital and astrometric parameters. For each pulsar, we also did a gamma-ray spectral analysis using LAT Pass 8 data and generated photon probabilities for use in a weighted H-test pulsation test. In all 4 cases, we detect significant gamma-ray pulsations, confirming the identification with the gamma-ray source originally targeted in the discovery observations. We describe the results of the pulse timing and gamma-ray spectral and timing analysis and the characteristics of each of the systems. The Fermi-LAT Collaboration acknowledges support for LAT development, operation and data analysis from NASA and DOE (United States), CEA/Irfu and IN2P3/CNRS (France), ASI and INFN (Italy), MEXT, KEK, and JAXA (Japan), and the K.A. Wallenberg Foundation, the Swedish Research Council and the National Space Board (Sweden). Science analysis support in the operations phase from INAF (Italy) and CNES (France) is also gratefully acknowledged. NRL participation was funded by NASA.

  11. Recent results in a search for inorganic scintillators for x- and gamma-ray detection

    SciTech Connect

    Moses, W.W.; Weber, M.J.; Derenzo, S.E.; Perry, D.; Berahl, P.

    1997-10-01

    We present recent results from an ongoing search for inorganic scintillators for gamma ray detection in which we measure the scintillation properties (luminous efficiency, decay time, and emission wavelength) of powdered samples excited by brief x-ray pulses. Recent promising candidates include cerium doped lutetium borate (LuBO{sub 3}) and the lutetium double phosphates K{sub 3}Lu(PO{sub 4}){sub 2} and Rb{sub 3}Lu(PO{sub 4}){sub 2}, which have luminous intensities above 25,000 photons/MeV. In order to find scintillators that are compatible with silicon photodetectors, we have tested over 1,100 samples using a photomultiplier tube with a GaAs:Cs photocathode, which is sensitive to emissions from 200-950 nm. While many samples exhibited strong emissions in the 600-900 nm range, all had decay times that were larger than 10 {mu}s.

  12. TPASS: a gamma-ray spectrum analysis and isotope identification computer code

    SciTech Connect

    Dickens, J.K.

    1981-03-01

    The gamma-ray spectral data-reduction and analysis computer code TPASS is described. This computer code is used to analyze complex Ge(Li) gamma-ray spectra to obtain peak areas corrected for detector efficiencies, from which are determined gamma-ray yields. These yields are compared with an isotope gamma-ray data file to determine the contributions to the observed spectrum from decay of specific radionuclides. A complete FORTRAN listing of the code and a complex test case are given.

  13. Analysis of proposed gamma-ray detection system for the monitoring of core water inventory in a pressurized water reactor

    SciTech Connect

    Markoff, D.M.

    1987-12-01

    An initial study has been performed of the feasibility of employing an axial array of gamma detectors located outside the pressure vessel to monitor the coolant in a PWR. A one-dimensional transport analysis model is developed for the LOFT research reactor and for a mock-PWR geometry. The gamma detector response to coolant voiding in the core and downcomer has been determined for both geometries. The effects of various conditions (for example, time after shutdown, materials in the transport path, and the relative void fraction in different water regions) on the detector response are studied. The calculational results have been validated by a favorable comparison with LOFT experimental data. Within the limitations and approximations considered in the analysis, the results indicate that the gamma-ray detection scheme is able to unambiguously respond to changes in the coolant inventory within any vessel water region.

  14. FIRST-YEAR RESULTS OF BROADBAND SPECTROSCOPY OF THE BRIGHTEST FERMI-GBM GAMMA-RAY BURSTS

    SciTech Connect

    Bissaldi, Elisabetta; Von Kienlin, Andreas; Greiner, Jochen; Gruber, David; Lichti, Giselher; Diehl, Roland; Foley, Suzanne; Kouveliotou, Chryssa; Fishman, Gerald J.; Fitzpatrick, Gerard; Gibby, Melissa H.; Giles, Misty M.; Van der Horst, Alexander J.

    2011-06-01

    We present our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (2008 July-2009 July).Our sample was selected from a total of 253 GBM GRBs based on the event peak count rate measured between 0.2 and 40 MeV. The final sample comprised of 34 long and 18 short GRBs. These numbers show that the GBM sample contains a much larger fraction of short GRBs than the CGRO/BATSE data set, which we explain as the result of our (different) selection criteria, which favor collection of short, bright GRBs over BATSE. A first by-product of our selection methodology is the determination of a detection threshold from the GBM data alone, above which GRBs most likely will be detected in the MeV/GeV range with the Large Area Telescope on board Fermi. This predictor will be very useful for future multi-wavelength GRB follow-ups with ground- and space-based observatories. Further, we have estimated the burst durations up to 10 MeV and for the first time expanded the duration-energy relationship in the GRB light curves to high energies. We confirm that GRB durations decline with energy as a power law with index approximately -0.4, as was found earlier with the BATSE data and we also notice evidence of a possible cutoff or break at higher energies. Finally, we performed time-integrated spectral analysis of all 52 bursts and compared their spectral parameters with those obtained with the larger data sample of the BATSE data. We find that the two parameter data sets are similar and confirm that short GRBs are in general harder than longer ones.

  15. First-year Results of Broadband Spectroscopy of the Brightest Fermi-GBM Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Bissaldi, Elisabetta; von Kienlin, Andreas; Kouveliotou, Chryssa; Briggs, Michael S.; Connaughton, Valerie; Greiner, Jochen; Gruber, David; Lichti, Giselher; Bhat, P. N.; Burgess, Michael; Chaplin, Vandiver; Diehl, Roland; Fishman, Gerald J.; Fitzpatrick, Gerard; Foley, Suzanne; Gibby, Melissa H.; Giles, Misty M.; Goldstein, Adam; Guiriec, Sylvain; van der Horst, Alexander J.; Kippen, R. Marc; Lin, Lin; McBreen, Sheila; Meegan, Charles A.; Paciesas, William S.; Preece, Robert D.; Rau, Arne; Tierney, Dave; Wilson-Hodge, Colleen

    2011-06-01

    We present our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (2008 July-2009 July).Our sample was selected from a total of 253 GBM GRBs based on the event peak count rate measured between 0.2 and 40 MeV. The final sample comprised of 34 long and 18 short GRBs. These numbers show that the GBM sample contains a much larger fraction of short GRBs than the CGRO/BATSE data set, which we explain as the result of our (different) selection criteria, which favor collection of short, bright GRBs over BATSE. A first by-product of our selection methodology is the determination of a detection threshold from the GBM data alone, above which GRBs most likely will be detected in the MeV/GeV range with the Large Area Telescope on board Fermi. This predictor will be very useful for future multi-wavelength GRB follow-ups with ground- and space-based observatories. Further, we have estimated the burst durations up to 10 MeV and for the first time expanded the duration-energy relationship in the GRB light curves to high energies. We confirm that GRB durations decline with energy as a power law with index approximately -0.4, as was found earlier with the BATSE data and we also notice evidence of a possible cutoff or break at higher energies. Finally, we performed time-integrated spectral analysis of all 52 bursts and compared their spectral parameters with those obtained with the larger data sample of the BATSE data. We find that the two parameter data sets are similar and confirm that short GRBs are in general harder than longer ones.

  16. Early Results for the Geochemistry of Vesta from Gamma Ray and Neutron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Prettyman, T. H.; Toplis, M. J.; Beck, A.; Feldman, W. C.; Forni, O.; Joy, S. P.; Lawrence, D. J.; McCoy, T. J.; McFadden, L. A.; McSween, H. Y.; Mittlefehldt, D. W.; Polanskey, C. A.; Rayman, M. D.; Raymond, C. A.; Reedy, R. C.; Russell, C. T.; Titus, T. N.

    2012-04-01

    ) spectrometer and framing camera (FC). We will present our initial analyses of GRaND data acquired in LAMO. Results from a few weeks of mapping are promising. Strong neutron and gamma ray signatures have been detected that can be analyzed to determine the abundance of H, Fe, Mg, Si, neutron absorption, and average atomic mass. The data acquired by GRaND reinforce the conclusion that Vesta is unusual compared to smaller asteroids, because its surface elemental composition shows considerable variation on a global scale. By this conference, we will be able to answer many of the science questions addressed by Dawn's Geochemistry investigation.1 1Prettyman T.H. et al. (2011), Dawn's Gamma Ray and Neutron Detector, Space Sci. Rev., DOI 10.1007/s11214-011-9862-0.

  17. Analysis of fissionable material using delayed gamma rays from photofission

    SciTech Connect

    Hollas, C.L.; Close, D.A.; Moss, C.E.

    1986-09-01

    The energetic gamma-ray spectra from the fission products of photofission have been investigated to determine whether photofission can identify heavily shielded fissionable material. Target samples of natural thorium, 93% enriched /sup 235/U, natural uranium, and 93% enriched /sup 239/Pu were irradiated with bremsstrahlung gamma rays produced by 10-MeV electrons from a small linear accelerator. The gamma-ray spectra for each of the four isotopes studied reveals a distinctive intensity distribution. For example, the intensity ratio of the pair of gamma rays at 1436 keV (/sup 138/Cs) and 1428 keV (/sup 94/Sr) is 1.9 for /sup 235/U, 2.4 for /sup 238/U, 1.7 for /sup 232/Th and 1.4 for /sup 239/Pu. 6 refs., 2 figs., 1 tab.

  18. Depleted uranium in Kosovo: results of a survey by gamma spectrometry on soil samples.

    PubMed

    Uyttenhove, J; Lemmens, M; Zizi, M

    2002-10-01

    The presence of depleted uranium in the soil of former Yugoslavia after the 1999 conflict raised great public concern all over the world. The so-called Balkan-syndrome is often linked with depleted uranium contamination. An excellent compilation of data about DU and its possible impact on health and environment can be found in the 1999 UNEP report and publications from the Swedish Radiation Protection Institute. Unfortunately, very few systematic and reliable data on the possible depleted uranium concentrations were until now available. Some of these rare data are only available on the web, without adequate information about the experimental procedure used. To clarify the situation, a systematic survey was started in the summer of 2000 as a collaborative effort between Ghent University (Physics Laboratory) and the Belgian Ministry of Defense (Medical Service). From 50 sites selected all over Kosovo, 150 soil samples were measured in the laboratory with a high-resolution gamma-spectrometer. Some sites (14) were explicitly selected based on military information on the use of depleted uranium munitions in the vicinity. After careful analysis we can conclude that there is no indication of any depleted uranium contamination on these 50 sites with a minimal detectable activity of 15 Bq; this corresponds approximately to 1 mg depleted uranium in a typical sample (100-150 g). PMID:12240731

  19. Hint1 knockout results in a compromised activation of protein kinase C gamma in the brain.

    PubMed

    Zhang, Fan; Fang, Zhenfei; Wang, Jia Bei

    2015-10-01

    Previous studies have implicated a role of the histidine triad nucleotide-binding protein 1 (Hint1) in the pathogenesis of schizophrenia. Protein kinase C gamma (PKCγ) could be potentially involved in the Hint1-implicated pathogenesis since PKCγ was identified as a Hint1 interacting protein. Recently, a debate was brought forward from the understanding how Hint1 affects the expression and activity of PKCγ in the brain. In the present study, we use Hint1 knockout mice and biochemical analysis to define the effect of Hint1 on protein PKCγ. Our data reveal that Hint1-deficiency in mouse brains led to increased protein levels of PKCγ in the cortex and hippocampus, the striatum and thalamus and amygdala. Without stimulation, PKCγ protein in Hint1-deficient brain displayed a basal activity that was reflected by control-leveled phosphorylations of PKCγ T514 and T674 at its kinase domain. Upon psycho-stimulation, both sites of PKCγ T514 and T674 were activated in these brain structures via phosphorylation; however, the phosphorylation level at the site of PKCγ T674 apparently attenuated in Hint1-deficient mice compared to wild-type control. Thus, we conclude that Hint1 deficiency leads to an increased protein level of PKCγ in the brain and a compromised activation response of PKCγ upon stimulation. These findings suggest an inhibitory role of Hint1 on the protein PKCγ in the brain and an impaired PKCγ-mediated phosphorylation signal in Hint1-deficient neuron. PMID:26133792

  20. Random amplified polymorphic DNA analysis of salt-tolerant tobacco mutants generated by gamma radiation.

    PubMed

    Çelik, Ö; Atak, Ç

    2015-01-01

    Salinity is one of the major problems limiting the yield of agricultural products. Radiation mutagenesis is used to improve salt-tolerant mutant plants. In this study, we aimed to improve salt-tolerant mutants of two oriental tobacco varieties. One thousand seeds of each variety (M₀) were irradiated with 100, 200, 300, and 400 Gy gamma rays by Cs-137 gamma. In the M₁ generation, 2999 single plants were harvested. The next season, these seeds were bulked and planted to obtain M₂ progeny. The seeds of 1900 M₂ plants were picked separately. Salinity tolerance was tested in the M₃ generation. Among M₃ plantlets, 10 salt-tolerant tobacco mutants were selected. According to the results of the selection studies, 100- and 200-Gy gamma radiation doses were the effective doses to obtain the desired mutants. Glutathione reductase enzyme activities of salt-tolerant tobacco mutants were determined biochemically as a stress-tolerance marker. The differences between control and salt-tolerant mutants belonging to the Akhisar 97 and İzmir Özbaş tobacco varieties were evaluated by random amplified polymorphic DNA analysis. The total polymorphism rate was 73.91%. PMID:25730072

  1. High Resolution Gamma Ray Analysis of Medical Isotopes

    NASA Astrophysics Data System (ADS)

    Chillery, Thomas

    2015-10-01

    Compton-suppressed high-purity Germanium detectors at the University of Massachusetts Lowell have been used to study medical radioisotopes produced at Brookhaven Linac Isotope Producer (BLIP), in particular isotopes such as Pt-191 used for cancer therapy in patients. The ability to precisely analyze the concentrations of such radio-isotopes is essential for both production facilities such as Brookhaven and consumer hospitals across the U.S. Without accurate knowledge of the quantities and strengths of these isotopes, it is possible for doctors to administer incorrect dosages to patients, thus leading to undesired results. Samples have been produced at Brookhaven and shipped to UML, and the advanced electronics and data acquisition capabilities at UML have been used to extract peak areas in the gamma decay spectra. Levels of Pt isotopes in diluted samples have been quantified, and reaction cross-sections deduced from the irradiation parameters. These provide both cross checks with published work, as well as a rigorous quantitative framework with high quality state-of-the-art detection apparatus in use in the experimental nuclear physics community.

  2. SER Analysis of MPPM-Coded MIMO-FSO System over Uncorrelated and Correlated Gamma-Gamma Atmospheric Turbulence Channels

    NASA Astrophysics Data System (ADS)

    Khallaf, Haitham S.; Garrido-Balsells, José M.; Shalaby, Hossam M. H.; Sampei, Seiichi

    2015-12-01

    The performance of multiple-input multiple-output free space optical (MIMO-FSO) communication systems, that adopt multipulse pulse position modulation (MPPM) techniques, is analyzed. Both exact and approximate symbol-error rates (SERs) are derived for both cases of uncorrelated and correlated channels. The effects of background noise, receiver shot-noise, and atmospheric turbulence are taken into consideration in our analysis. The random fluctuations of the received optical irradiance, produced by the atmospheric turbulence, is modeled by the widely used gamma-gamma statistical distribution. Uncorrelated MIMO channels are modeled by the α-μ distribution. A closed-form expression for the probability density function of the optical received irradiance is derived for the case of correlated MIMO channels. Using our analytical expressions, the degradation of the system performance with the increment of the correlation coefficients between MIMO channels is corroborated.

  3. Recent Results from the Excitation of Dipole States at the HI{gamma}S Facility

    SciTech Connect

    Tonchev, A. P.; Hutcheson, A.; Kwan, E.; Rusev, G.; Tornow, W.; Angell, C.; Hammond, S.; Karwowski, H. J.; Kelley, J. H.; Tsoneva, N.

    2009-01-28

    High-sensitivity studies of E1 and M1 excitations observed in the {sup 138}Ba({gamma},{gamma}') reaction at energies below the neutron emission threshold have been performed. The electric dipole character of the so-called 'pygmy' mode was experimentally verified for excitations from 4.0-8.6 MeV. The fine structure of the M1 'spin-flip' mode was observed for the first time in N = 82 nuclei.

  4. The Fermi Gamma-Ray Space Telescope - Overview and Early Science Results

    NASA Technical Reports Server (NTRS)

    Leibee, Jack; Seidleck, Mark; McEnery, Julie

    2009-01-01

    The Fermi Gamma-ray Space Telescope (formerly named GLAST) was designed and built by NASA, many cooperating foreign space agencies, and the United States Department of Energy. It launched in June of 2008 and has been observing gamma-ray bursts for over 8 months. This paper describes the mission systems and the mission overview; how the instruments work; summarizes the on-orbit activation, and discusses the most recent science highlights.

  5. Analysis of spectra from portable handheld gamma-ray spectrometry for terrain comparative assessment.

    PubMed

    Dias, Flávio; Lima, Marco; Sanjurjo-Sánchez, Jorge; Alves, Carlos

    2016-04-01

    Geological characteristics can have impacts on societal development by, e.g., geotechnical issues and radiological hazard levels. Due to urban sprawl, there is an increasing need for detailed geological assessment. In this work are analysed data from portable handheld gamma-ray spectra (K, eU and eTh) obtained in granitic and Silurian metaclastic outcrops as well as in an profile, roughly N-S, on soil covered terrains transecting a mapped contact between these rock types (the profile's northern extremity is at locations mapped as granite). Estimations from gamma-ray spectra were studied by univariate and multivariate analyses. K, eU and eTh values were higher on granite in relation to Silurian metaclastic rocks. The northern extremity of the profile showed clearly higher contents of eTh and this contrast was supported by univariate statistical tools (normality plot and Wilk-Shapiro test; boxplots). A ternary plot with the contribution of the elements to gamma-ray absorbed dose showed the separation of granite from Silurian metaclastic rocks with the former being nearer the eTh vertex. The points in the northern extremity of the profile are nearer the eTh vertex than the other points on the profile. These visual suggestions were supported by hierarchical cluster analysis, which was able to differentiate between granite and metaclastic outcrops and separate portions of the profile located on different terrains. Portable gamma-ray spectrometry showed, hence, the potential to distinguish granite and metaclastic terrains at a scale useful for engineering works. These results can also be useful for a first comparative zoning of radiological hazards (which are higher for granite). PMID:26867098

  6. BATSE software for the analysis of the gamma ray burst spatial distribution

    NASA Technical Reports Server (NTRS)

    Hakkila, Jon

    1990-01-01

    The Burst and Transient Source Experiment (BATSE) on the Gamma Ray Observatory (GRO) is designed to study astronomical gamma ray sources and to provide better positional, spectral, and time resolution about these objects than has previously been possible from one experiment. The procedure to be used in the analysis of the gamma ray burst spatial distribution is presented. Data is input from BATSE via the Gamma Ray Burst Catalog (listing individual burst positions, flux values, and associated errors) and the Sky Sensitivity Map (which summarizes observational selection effects in table format). A FORTRAN program generates Monte Carlo burst catalogs, which are models to be compared to the actual distribution. The Monte Carlo models are then filtered through the Sky Sensitivity Map so that they suffer from the same selection effects as the actual catalog data. Additionally, each burst position is converted into a probability distribution to mimic BATSE positional sensitivity. The Burst Catalog, Monte Carlo burst catalog, and Sky Sensitivity Map are then passed onto an IDL program that compares the catalogs for statistical significance. The Sky Sensitivity Map is used to estimate how often each sky area is observed above the minimum flux level in question. Each burst found in this sky area is then weighted according to the frequency with which this sky area is observed. The catalogs are then compared via tests of homogeneity (based on their radial distributions) and isotropy (based upon their angular distributions). The results of the statistical comparisons along with graphs and charts of the summaries, are output from the IDL program for study.

  7. PSR J0007+7303 IN THE CTA1 SUPERNOVA REMNANT: NEW GAMMA-RAY RESULTS FROM TWO YEARS OF FERMI LARGE AREA TELESCOPE OBSERVATIONS

    SciTech Connect

    Abdo, A. A.; Parent, D.; Wood, K. S.; Ray, P. S.; Wolff, M. T.; DeCesar, M. E.; Harding, A. K.; Gargano, F.; Giordano, F.; Coleman Miller, M.; Wood, D. L.

    2012-01-10

    One of the main results of the Fermi Gamma-Ray Space Telescope is the discovery of {gamma}-ray selected pulsars. The high magnetic field pulsar, PSR J0007+7303 in CTA1, was the first ever to be discovered through its {gamma}-ray pulsations. Based on analysis of two years of Large Area Telescope (LAT) survey data, we report on the discovery of {gamma}-ray emission in the off-pulse phase interval at the {approx}6{sigma} level. The emission appears to be extended at the {approx}2{sigma} level with a disk of extension {approx}0.{sup 0}6. level. The flux from this emission in the energy range E {>=} 100 MeV is F{sub 100} = (1.73 {+-} 0.40{sub stat} {+-} 0.18{sub sys}) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1} and is best fitted by a power law with a photon index of {Gamma} = 2.54 {+-} 0.14{sub stat} {+-} 0.05{sub sys}. The pulsed {gamma}-ray flux in the same energy range is F{sub 100} = (3.95 {+-} 0.07{sub stat} {+-} 0.30{sub sys}) Multiplication-Sign 10{sup -7} photons cm{sup -2} s{sup -1} and is best fitted by an exponentially cutoff power-law spectrum with a photon index of {Gamma} = 1.41 {+-} 0.23{sub stat} {+-} 0.03{sub sys} and a cutoff energy E{sub c} = 4.04 {+-} 0.20{sub stat} {+-} 0.67{sub sys} GeV. We find no flux variability either at the 2009 May glitch or in the long-term behavior. We model the {gamma}-ray light curve with two high-altitude emission models, the outer gap and slot gap, and find that the preferred model depends strongly on the assumed origin of the off-pulse emission. Both models favor a large angle between the magnetic axis and observer line of sight, consistent with the nondetection of radio emission being a geometrical effect. Finally, we discuss how the LAT results bear on the understanding of the cooling of this neutron star.

  8. Strong constraints on gamma-ray burst emission in TeV using recent results from VERITAS

    NASA Astrophysics Data System (ADS)

    Weiner, Ori

    2016-04-01

    Recent VERITAS gamma-ray upper limits in the energy range 100 GeV to 30 TeV suggest that gamma-ray burst (GRB) emission in TeV is substantially suppressed compared to X-ray emission, and even compared to typically-observed Fermi-LAT emission in GeV. These results impact on our understanding of the GRB environment. We will present VERITAS results on GRB150323A and put them in context of what has been seen at lower energies by Swift and Fermi, both for this particular burst and for others.

  9. Gamma knife radiosurgery of craniopharyngioma: results of 30 cases treated at Nagoya Radiosurgery Center

    PubMed Central

    Kobayashi, Tatsuya; Tsugawa, Takahiko; Hatano, Manabu; Hashizume, Chisa; Mori, Yoshimasa; Shibamoto, Yuta

    2015-01-01

    ABSTRACT Evaluation of 30 cases of craniopharyngioma treated by Gamma Knife at Nagoya Radiosurgery Center (NRC), Nagoya Kyoritsu Hospital since July, 2004 has been made. The mean volume of the tumor was 2.64 ml, which was treated with the marginal dose of 11.7 Gy. Mean follow-up period was 79.9 months. The effects were evaluated by MRI findings, neuro-endocrine and hypothalamic signs and symptoms, complications and KPS every 3~6 months. As the results, complete remission was obtained in 8, partial remission in 12, no change in 6, progression in 3, in which two died by hypothalamic invasion. Tumor response rate was 68.9% and control rate 87.9%. Actuarial survival was 96% at 5 and 86% at 10 years. However, progression free survival was 76% and 76%, respectively. Using marginal dose of 11.7Gy to a smaller tumor, better control without complications has been obtained. KPS was excellent in 14, good in 9, fair in 2, poor in 1 and unknown in a case. Finally, there were three deaths, where two were died of tumor progression and one by infirmity. The progression of hypothalamic symptoms other than diabetes insipidus were found in two cases. Volume reduction and effective dose setting will be important for the improvement of QOL and survival after combined microsurgery and radiosurgery of craniopharyngioma. PMID:26412891

  10. Performance analysis of satellite-to-ground downlink optical communications with spatial diversity over Gamma-Gamma atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Li, Kangning; Ma, Jing; Belmonte, Aniceto; Tan, Liying; Yu, Siyuan

    2015-12-01

    The performances of satellite-to-ground downlink optical communications over Gamma-Gamma distributed turbulence are studied for a multiple-aperture receiver system. Equal gain-combining (EGC) and selection-combining (SC) techniques are considered as practical schemes to mitigate the atmospheric turbulence under thermal-noise-limited conditions. Bit-error rate (BER) performances for on-off keying-modulated direct detection and outage probabilities are analyzed and compared for SC diversity receptions using analytical results and for EGC diversity receptions through an approximation method. To show the net diversity gain of a multiple-aperture receiver system, BER performances and outage probabilities of EGC and SC receiver systems are compared with a single monolithic-aperture receiver system with the same total aperture area (same average total incident optical power) for satellite-to-ground downlink optical communications. All the numerical results are also verified by Monte-Carlo simulations.

  11. Performance analysis of satellite-to-ground downlink coherent optical communications with spatial diversity over Gamma-Gamma atmospheric turbulence.

    PubMed

    Ma, Jing; Li, Kangning; Tan, Liying; Yu, Siyuan; Cao, Yubin

    2015-09-01

    The performances of satellite-to-ground downlink optical communications over Gamma-Gamma distributed atmospheric turbulence are studied for a coherent detection receiving system with spatial diversity. Maximum ratio combining (MRC) and selection combining (SC) techniques are considered as practical schemes to mitigate the atmospheric turbulence. Bit-error rate (BER) performances for binary phase-shift keying modulated coherent detection and outage probabilities are analyzed and compared for SC diversity using analytical results and for MRC diversity through an approximation method with different numbers of receiving aperture each with the same aperture area. To show the net diversity gain of a multiple aperture receiver system, BER performances and outage probabilities of MRC and SC multiple aperture receiver systems are compared with a single monolithic aperture with the same total aperture area (same total average incident optical power) for satellite-to-ground downlink optical communications. All the numerical results are verified by Monte-Carlo simulations. PMID:26368880

  12. A single nucleotide insertion in the canine interleukin-2 receptor gamma chain results in X-linked severe combined immunodeficiency disease.

    PubMed

    Somberg, R L; Pullen, R P; Casal, M L; Patterson, D F; Felsburg, P J; Henthorn, P S

    1995-08-01

    The immunologic and genetic analysis of a 14-week-old-male cardigan Welsh corgi puppy that presented with failure to thrive, diarrhea, and intermittent vomiting are described. The lack of palpable lymph nodes, the premature death of a male sibling, and similar clinical signs in a male cousin suggested that a primary immunodeficiency disease might be responsible for his poor clinical condition. Quantitation of serum immunoglobulins revealed low concentrations of IgG and undetectable IgA, yet normal concentrations of IgM. A complete blood cell count showed a slight anemia and lymphopenia. Although the peripheral blood contained a normal percentage of T cells, with an increased CD4:CD8 ratio, they were unable to proliferate in response to phytohemagglutinin (PHA) and/or interleukin 2 (IL-2). Furthermore, following PHA activation, the peripheral blood lymphocytes (PBL) demonstrated a nearly complete lack of IL-2 binding. All of these laboratory findings were identical with our previous findings from dogs with X-linked severe combined immunodeficiency (XSCID) that is due to a mutation in their IL-2 receptor gamma (IL-2R gamma) chain. Examination of the corgi's IL-2R gamma cDNA revealed an insertion of a cytosine following nucleotide 582, resulting in a premature stop codon prior to the transmembrane domain. The insertion also created an EcoO109 restriction enzyme site that enabled us to detect the mutation in the patient's genomic DNA. This new mutation in the IL-2R gamma chain discovered in a cardigan Welsh corgi puppy results in XSCID with similar immunologic abnormalities as observed in dogs with the same disease resulting from a different IL-2R gamma chain mutation. PMID:8571541

  13. Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

    SciTech Connect

    Stamatikos, Michael; Sakamoto, Takanori; Band, David L.

    2008-05-22

    We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (E{sub peak}) values, for a conservative annual estimate of {approx}30 GRBs. The addition of BAT/s spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the {approx}20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade.

  14. Empirical correlation of residual gamma radiation resulting from operation of the Health Physics Research Reactor

    SciTech Connect

    Chou, T.L.; Ragan, G.E.; Sims, C.S.

    1985-04-01

    An empirical equation has been developed which gives gamma dose equivalent rate as a function of time, distance, and fission yield after a pulsed operation of Oak Ridge National Laboratory's (ORNL) unshielded Health Physics Research Reactor (HPRR). A related expression which is applicable to steady-state reactor operation has been mathematically derived from the aforementioned empirical equation. The two relations can be used to predict the gamma dose equivalent rate to within 25% for times between 1 minute and 90 minutes after reactor shutdown. Similar agreement is expected for up to several days. In most cases the relations are expected to overestimate the gamma dose equivalent rate. 5 refs., 4 figs., 1 tab.

  15. Observations of the galactic center with the GSFC low-energy gamma-ray spectrometer - Preliminary results

    NASA Technical Reports Server (NTRS)

    Paciesas, W. S.; Tueller, J.; Cline, T. L.; Teegarden, B. J.; Durouchoux, P.; Hameury, J. M.

    1982-01-01

    The results of measurements made of the gamma ray emission originating from the galactic center are reviewed. The data were gathered with balloon borne gamma ray spectrometers, with the scans centering on 511 keV. Minimum Chi-sq fits were calculated for the recorded emissions, assuming a constant source modulated by the detector response and superimposed on a constant background. A time history of the 511 keV line intensity demonstrated variability in the feature, whereas the continuum spectrum showed a high correlation with previous measurements. An excess in the continuum just below the 511 keV line was taken as an indication of positronium formation.

  16. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1991-01-01

    Miscellaneous tasks related to the development of the Bursts and Transient Source Experiment on the Gamma Ray Observatory and to analysis of archival data from balloon flight experiments were performed. The results are summarized and relevant references are included.

  17. A NEW RESULT ON THE ORIGIN OF THE EXTRAGALACTIC GAMMA-RAY BACKGROUND

    SciTech Connect

    Zhou Ming; Wang Jiancheng

    2013-06-01

    In this paper, we repeatedly use the method of image stacking to study the origin of the extragalactic gamma-ray background (EGB) at GeV bands, and find that the Faint Images of the Radio Sky at Twenty centimeters (FIRST) sources undetected by the Large Area Telescope on the Fermi Gamma-ray Space Telescope can contribute about (56 {+-} 6)% of the EGB. Because FIRST is a flux-limited sample of radio sources with incompleteness at the faint limit, we consider that point sources, including blazars, non-blazar active galactic nuclei, and starburst galaxies, could produce a much larger fraction of the EGB.

  18. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    SciTech Connect

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  19. Long-Term Results for Trigeminal Schwannomas Treated With Gamma Knife Surgery

    SciTech Connect

    Hasegawa, Toshinori Kato, Takenori; Iizuka, Hiroshi; Kida, Yoshihisa

    2013-12-01

    Purpose: Surgical resection is considered the desirable curative treatment for trigeminal schwannomas. However, complete resection without any complications remains challenging. During the last several decades, stereotactic radiosurgery (SRS) has emerged as a minimally invasive treatment modality. Information regarding long-term outcomes of SRS for patients harboring trigeminal schwannomas is limited because of the rarity of this tumor. The aim of this study was to evaluate long-term tumor control and functional outcomes in patients harboring trigeminal schwannomas treated with SRS, specifically with gamma knife surgery (GKS). Methods and Materials: Fifty-three patients harboring trigeminal schwannomas treated with GKS were evaluated. Of these, 2 patients (4%) had partial irradiation of the tumor, and 34 patients (64%) underwent GKS as the initial treatment. The median tumor volume was 6.0 cm{sup 3}. The median maximum and marginal doses were 28 Gy and 14 Gy, respectively. Results: The median follow-up period was 98 months. On the last follow-up image, 7 patients (13%) had tumor enlargement, including the 2 patients who had partial treatment. Excluding the 2 patients who had partial treatment, the actuarial 5- and 10-year progression-free survival (PFS) rates were 90% and 82%, respectively. Patients with tumors compressing the brainstem with deviation of the fourth ventricle had significantly lower PFS rates. If those patients with tumors compressing the brainstem with deviation of the fourth ventricle are excluded, the actuarial 5- and 10-year PFS rates increased to 95% and 90%, respectively. Ten percent of patients had worsened facial numbness or pain in spite of no tumor progression, indicating adverse radiation effect. Conclusions: GKS can be an acceptable alternative to surgical resection in patients with trigeminal schwannomas. However, large tumors that compress the brainstem with deviation of the fourth ventricle should be surgically removed first and then

  20. Contralateral parahippocampal gamma-band activity determines noise-like tinnitus laterality: a region of interest analysis.

    PubMed

    Vanneste, S; Heyning, P Van de; Ridder, D De

    2011-12-29

    Tinnitus is described as an auditory perception in the absence of any external sound source. Tinnitus loudness has been correlated to sustained high frequency gamma-band activity in auditory cortex. It remains unknown whether unilateral tinnitus is always generated in the left auditory cortex, irrespective of the side on which the tinnitus is perceived, or in the contralateral auditory cortex. In order to solve this enigma source localized electroencephalographic (EEG) recordings of a homogenous group of unilateral left and right-sided tinnitus patients presenting with noise-like tinnitus was analyzed. Based on a region of interest analysis, the most important result of this study is that tinnitus lateralization depended on the gamma-band activity of the contralateral parahippocampal area. As for the auditory cortex no differences were found between left-sided and right-sided tinnitus patients. However, in comparison to a control group both left and right-sided tinnitus patients had an increased gamma-band activity in both the left and right primary and secondary auditory cortex. Thus whereas in tinnitus the primary and secondary auditory cortices of both sides are characterized by increased gamma-band activity, the side on which the tinnitus is perceived relates to gamma-band activity in the contralateral parahippocampal area. PMID:21920411

  1. Database of prompt gamma rays from slow neutron capture forelemental analysis

    SciTech Connect

    Firestone, R.B.; Choi, H.D.; Lindstrom, R.M.; Molnar, G.L.; Mughabghab, S.F.; Paviotti-Corcuera, R.; Revay, Zs; Trkov, A.; Zhou,C.M.; Zerkin, V.

    2004-12-31

    The increasing importance of Prompt Gamma-ray ActivationAnalysis (PGAA) in a broad range of applications is evident, and has beenemphasized at many meetings related to this topic (e.g., TechnicalConsultants' Meeting, Use of neutron beams for low- andmedium-fluxresearch reactors: radiography and materialscharacterizations, IAEA Vienna, 4-7 May 1993, IAEA-TECDOC-837, 1993).Furthermore, an Advisory Group Meeting (AGM) for the Coordination of theNuclear Structure and Decay Data Evaluators Network has stated that thereis a need for a complete and consistent library of cold- and thermalneutron capture gammaray and cross-section data (AGM held at Budapest,14-18 October 1996, INDC(NDS)-363); this AGM also recommended theorganization of an IAEA CRP on the subject. The International NuclearData Committee (INDC) is the primary advisory body to the IAEA NuclearData Section on their nuclear data programmes. At a biennial meeting in1997, the INDC strongly recommended that the Nuclear Data Section supportnew measurements andupdate the database on Neutron-induced PromptGamma-ray Activation Analysis (21st INDC meeting, INDC/P(97)-20). As aconsequence of the various recommendations, a CRP on "Development of aDatabase for Prompt Gamma-ray Neutron Activation Analysis (PGAA)" wasinitiated in 1999. Prior to this project, several consultants had definedthe scope, objectives and tasks, as approved subsequently by the IAEA.Each CRP participant assumed responsibility for the execution of specifictasks. The results of their and other research work were discussed andapproved by the participants in research co-ordination meetings (seeSummary reports: INDC(NDS)-411, 2000; INDC(NDS)-424, 2001; andINDC(NDS)-443, 200). PGAA is a non-destructive radioanalytical method,capable of rapid or simultaneous "in-situ" multi-element analyses acrossthe entire Periodic Table, from hydrogen to uranium. However, inaccurateand incomplete data were a significant hindrance in the qualitative andquantitative

  2. Chang’E-1 gamma ray spectrometer and preliminary radioactive results on the lunar surface

    NASA Astrophysics Data System (ADS)

    Zhu, Meng-Hua; Ma, Tao; Chang, Jin

    2010-10-01

    The Chang'E-1(CE-1) spacecraft took a gamma-ray spectrometer (hereafter, CGRS) to detect the element distributions on the lunar surface in a circular, 200 km altitude, polar orbit with approximately 2 h periodicity. CGRS consists of two large CsI(Tl) crystals as the main and anticoincidence detectors. The large CsI crystal of CGRS has a higher detector effective area than other lunar gamma ray spectrometers. For its 1-year mission, gamma ray spectra including many peaks of major elements and trace elements on the lunar surface have been measured by CGRS. Global measurement within 0.55-0.75 MeV is given here to describe the distribution of radioactive composition (e.g., uranium and thorium) on the lunar surface. Although CGRS has a lower energy resolution that cannot separate the uranium peak from others in this energy region, 609 keV uranium gamma ray line dominates the shape of the spectrum in this energy region. Therefore, the radioactive map can indirectly describe the uranium distribution on the lunar surface. The radioactive map shows that the higher radiation is concentrated in the Procellarum KREEP Terrene (PKT) on the nearside with an oval shape. The secondary high-radiation is located in South Pole-Aitken (SPA) basin. Lunar highlands have lower concentration. The relationship between radiation and topography displays different linear correlations for lunar highlands and SPA basin, which imply the different processes for these two regions.

  3. Tom Bonner Prize: Gamma-ray energy tracking array GRETINA and its early science results

    NASA Astrophysics Data System (ADS)

    Lee, I.-Yang

    2016-03-01

    Gamma-ray detector with good energy resolution has been one of the essential instruments for the study of nuclear structure. To push these studies toward the exotic nuclei near the particle stability line, we need detectors with higher peak efficiency and good peak-to-total ratio. In addition, radioactive ion beams needed for such studies are often produced by the projectile fragmentation method. They have high velocities, and detectors must provide adequate position resolution for accurate Doppler correction. To fulfill these requirements, the new concept of gamma ray energy tracking array was developed. GRETINA, with 1 π solid angle coverage, is the first implementation of this concept. It uses electrically segmented Ge crystals in a close packed geometry, fast digital electronics, and signal decomposition to determine the position and energy of the individual interaction points. Then the path of a gamma ray can be tracked using the angle-energy relation of the scattering process. GRETINA was completed at LBNL and started physics operation in 2012. It has been used at NSCL at MSU and ATLAS at ANL for a large number of experiments addressing diverse topics from nuclear structure to nuclear astrophysics. In this talk I will describe the concept of gamma-ray energy tracking and the technology developed for GRETINA. A few representative experiments showing the breadth of the science and the power of the instrument will be discussed. Finally the plan toward the full 4 π array GRETA will be presented.

  4. Report on Ultra-high Resolution Gamma- / X-ray Analysis of Uranium Skull Oxide

    SciTech Connect

    Friedrich, S; Velazquez, M; Drury, O; Salaymeh, S

    2009-11-02

    We have utilized the high energy resolution and high peak-to-background ratio of superconducting TES {gamma}-detectors at very low energies for non-destructive analysis of a skull oxide derived from reprocessed nuclear fuel. Specifically, we demonstrate that superconducting detectors can separate and analyze the strong actinide emission lines in the spectral region below 60 keV that are often obscured in {gamma}-measurements with conventional Ge detectors.

  5. Exploratory visual analysis of pharmacogenomic results.

    PubMed

    Reif, David M; Dudek, Scott M; Shaffer, Christian M; Wang, Janey; Moore, Jason H

    2005-01-01

    Comprehensive analysis of expansive pharmacogenomic datasets is a daunting challenge. A thorough exploration of experimental results requires both statistical and annotative information. Therefore, appropriate analysis tools must bring a readily-accessible, flexible combination of statistics and biological annotation to the user's desktop. We present the Exploratory Visual Analysis (EVA) software and database as such a tool and demonstrate its utility in replicating the findings of an earlier pharmacogenomic study as well as elucidating novel biologically plausible hypotheses. EVA brings all of the often disparate pieces of analysis together in an infinitely flexible visual display that is amenable to any type of statistical result and biological question. Here, we describe the motivations for developing EVA, detail the database and custom graphical user interface (GUI), provide an example of its application to a publicly available pharmacogenomic dataset, and discuss the broad utility of the EVA tool for the pharmacogenomics community. PMID:15759635

  6. "Chiron": A Proposed Remote Sensing Prompt Gamma Ray Activation Analysis Instrument for a Nuclear Powered Prometheus Mission

    NASA Technical Reports Server (NTRS)

    Floyd, Samuel R.; Keller, John W.; Dworkin, Jason P.; Mildner, David F. R.

    2004-01-01

    Prompt Gamma Ray Activation Analysis (PGAA) from neutron capture is an important experimental method that yields information on the elemental abundance of target materials. Gamma ray analysis has been used in planetary exploration missions by taking advantage of the production of neutrons as a result of Galactic Cosmic Ray interaction within the planetary surfaces. The .gamma ray signal that can be obtained from the GCR production of neutrons is very low, so we seek a superior neutron source. NASA s Project Prometheus and the Dept. of Energy aim to develop a nuclear power system for planetary exploration. This provides us with a tremendous opportunity to harness the reactor as a source of neutrons that can be used for PGAA. We envision a narrow stream of neutrons from the reactor directed toward the surface of an asteroid or comet producing the prompt gamma ray signal for analysis. Under ideal conditions of neutron flux and spacecraft orbit, both the signal strength and the spatial resolution will improved by several orders of magnitude over previously missions.

  7. Analysis of the Swift Gamma-Ray Bursts duration

    SciTech Connect

    Horvath, I.; Veres, P.; Balazs, L. G.; Kelemen, J.; Bagoly, Z.

    2008-10-22

    Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanalyze the durations and their distribution and also the classification of GRBs. Using The First BAT Catalog the maximum likelihood estimation was used to analyzed the duration distribution of GRBs. The three log-normal fit is significantly (99.54% probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2%)

  8. Gamma Detector Response and Analysis Software - Detector Response Function

    Energy Science and Technology Software Center (ESTSC)

    2014-05-13

    GADRAS-DRF uses a Detector Response Function (DRF) to compute the response of gamma-ray detectors incident radiation. The application includes provision for plotting measured and computed spectra and for characterizing detector response parameters based on measurements of a series of calibration sources (e.g., Ba-133, Cs-137, Co-60, and Th-228). An application program interface enables other programs to access the dynamic-link library that is used to compute spectra.

  9. Relativity concept inventory: Development, analysis, and results

    NASA Astrophysics Data System (ADS)

    Aslanides, J. S.; Savage, C. M.

    2013-06-01

    We report on a concept inventory for special relativity: the development process, data analysis methods, and results from an introductory relativity class. The Relativity Concept Inventory tests understanding of relativistic concepts. An unusual feature is confidence testing for each question. This can provide additional information; for example, high confidence correlated with incorrect answers suggests a misconception. A novel aspect of our data analysis is the use of Monte Carlo simulations to determine the significance of correlations. This approach is particularly useful for small sample sizes, such as ours. Our results show a gender bias that was not present in course assessment, similar to that reported for the Force Concept Inventory.

  10. Prompt gamma ray evaluation for chlorine analysis in blended cement concrete.

    PubMed

    Naqvi, A A; Maslehuddin, M; Kalakada, Zameer; Al-Amoudi, O S B

    2014-12-01

    Single prompt gamma ray energy has been evaluated to measure chlorine concentration in fly ash (FA), Super-Pozz (SPZ) and blast furnace slag (BFS) cement concrete specimens using a portable neutron generator-based Prompt Gamma Neutron Activation (PGNAA) setup. The gamma ray yield data from chloride concentration measurement in FA, SPZ and BFS cement concretes for 2.86-3.10, 5.72 and 6.11MeV chlorine gamma rays were analyzed to identify a gamma ray with common slope (gamma ray yield/Cl conc. wt%) for the FA, BFS and SPZ cement concretes. The gamma ray yield data for FA and SPZ cement concretes with varying chloride concentration were measured previously using a portable neutron generator-based PGNAA setup. In the current study, new data have been measured for chlorine detection in the BFS cement concrete using a portable neutron generator-based PGNAA setup for 2.86-3.10, 5.72, and 6.11MeV chlorine gamma rays. The minimum detection limit of chlorine in BFS cement concrete (MDC) was found to be 0.034±0.010, 0.032±0.010, 0.033±0.010 for 2.86-3.10, 5.72 and 6.11MeV gamma ray, respectively. The new BFS cement concrete data, along with the previous measurements for FA and SPZ cement concretes, have been utilized to identify a gamma ray with a common slope to analyze the Cl concentration in all of these blended cement concretes. It has been observed that the 6.11MeV chlorine gamma ray has a common slope of 5295±265 gamma rays/wt % Cl concentration for the portable neutron generator-based PGNAA setup. The minimum detectable concentration (MDC) of chlorine in blended cement concrete was measured to be 0.033±0.010wt % for the portable neutron generator-based PGNAA. Thus, the 6.11MeV chlorine gamma ray can be used for chlorine analysis of blended cement concretes. PMID:25063940

  11. Application of the V-Gamma map to vehicle breakup analysis

    NASA Technical Reports Server (NTRS)

    Salama, Ahmed; McRonald, Angus; Ahmadi, Reza; LIng, Lisa; Accad, Elie; Kim, Alex

    2003-01-01

    The V-Gamma map consists of all possible pairs of speed and flight path angle at atmospheric entry interface for accidental Earth reentries resulting from steady misaligned burns, incomplete burns, or no burn.

  12. Analysis of Data from the Balloon Borne Gamma RAy Polarimeter Experiment (GRAPE)

    NASA Astrophysics Data System (ADS)

    Wasti, Sambid K.; Bloser, Peter F.; Legere, Jason S.; McConnell, Mark L.; Ryan, James M.

    2016-04-01

    The Gamma Ray Polarimeter Experiment (GRAPE), a balloon borne polarimeter for 50~300 keV gamma rays, successfully flew in 2011 and 2014. The main goal of these balloon flights was to measure the gamma ray polarization of the Crab Nebula. Analysis of data from the first two balloon flights of GRAPE has been challenging due to significant changes in the background level during each flight. We have developed a technique based on the Principle Component Analysis (PCA) to estimate the background for the Crab observation. We found that the background depended mostly on the atmospheric depth, pointing zenith angle and instrument temperatures. Incorporating Anti-coincidence shield data (which served as a surrogate for the background) was also found to improve the analysis. Here, we present the calibration data and describe the analysis done on the GRAPE 2014 flight data.

  13. Expert system for imaging spectrometer analysis results

    NASA Technical Reports Server (NTRS)

    Borchardt, Gary C.

    1985-01-01

    Information on an expert system for imaging spectrometer analysis results is outlined. Implementation requirements, the Simple Tool for Automated Reasoning (STAR) program that provides a software environment for the development and operation of rule-based expert systems, STAR data structures, and rule-based identification of surface materials are among the topics outlined.

  14. Relativity Concept Inventory: Development, Analysis, and Results

    ERIC Educational Resources Information Center

    Aslanides, J. S.; Savage, C. M.

    2013-01-01

    We report on a concept inventory for special relativity: the development process, data analysis methods, and results from an introductory relativity class. The Relativity Concept Inventory tests understanding of relativistic concepts. An unusual feature is confidence testing for each question. This can provide additional information; for example,…

  15. TOPICAL REVIEW: Human soft tissue analysis using x-ray or gamma-ray techniques

    NASA Astrophysics Data System (ADS)

    Theodorakou, C.; Farquharson, M. J.

    2008-06-01

    This topical review is intended to describe the x-ray techniques used for human soft tissue analysis. X-ray techniques have been applied to human soft tissue characterization and interesting results have been presented over the last few decades. The motivation behind such studies is to provide improved patient outcome by using the data obtained to better understand a disease process and improve diagnosis. An overview of theoretical background as well as a complete set of references is presented. For each study, a brief summary of the methodology and results is given. The x-ray techniques include x-ray diffraction, x-ray fluorescence, Compton scattering, Compton to coherent scattering ratio and attenuation measurements. The soft tissues that have been classified using x-rays or gamma rays include brain, breast, colon, fat, kidney, liver, lung, muscle, prostate, skin, thyroid and uterus.

  16. Early results utilizing high-energy fission product (gamma) rays to detect fissionable material in cargo

    SciTech Connect

    Slaughter, D R; Accatino, M R; Bernstein, A; Church, J A; Descalle, M A; Gosnell, T B; Hall, J M; Loshak, A; Manatt, D R; Mauger, G J; McDowell, M; Moore, T M; Norman, E B; Pohl, B A; Pruet, J A; Petersen, D C; Walling, R S; Weirup, D L; Prussin, S G

    2004-09-30

    A concept for detecting the presence of special nuclear material ({sup 235}U or {sup 239}Pu) concealed in intermodal cargo containers is described. It is based on interrogation with a pulsed beam of 7 MeV neutrons that produce fission events and their {beta}-delayed neutron emission or {beta}-delayed high-energy {gamma}-radiation between beam pulses provide the detection signature. Fission product {beta}-delayed {gamma}-rays above 3 MeV are nearly ten times more abundant than {beta}-delayed neutrons and are distinct from natural radioactivity and from nearly all of the induced activity in a normal cargo. Detector backgrounds and potential interferences with the fission signature radiation have been identified and quantified. An important goal in the US is the detection of nuclear weapons or special nuclear material (SNM) concealed in intermodal cargo containers. This must be done with high detection probability, low false alarm rates, and without impeding commerce, i.e. about one minute for an inspection. The concept for inspection has been described before and its components are now being evaluated. While normal radiations emitted from plutonium may allow its detection, the majority of {sup 235}U {gamma} ray emission is at 186 keV, is readily attenuated by cargo, and thus not a reliable detection signature for passive detection. Delayed neutron detection following a neutron or photon beam pulse has been used successfully to detect lightly or unshielded SNM targets. While delayed neutrons can be easily distinguished from beam neutrons they have relatively low yield in fission, approximately 0.008 per fission in {sup 239}Pu and 0.017 per fission in {sup 235}U, and are rapidly attenuated in hydrogenous materials making that technique unreliable when challenged by thick hydrogenous cargo overburden. They propose detection of {beta}-delayed high-energy {gamma} radiation as a more robust signature characteristic of SNM.

  17. Utilization of recycled neutron source to teach prompt gamma analysis activation-PGNA

    NASA Astrophysics Data System (ADS)

    Delgado-Correal, Camilo; Munera, Hector

    2008-03-01

    Neutron activation analysis based on prompt gamma ray emission has significantly developed during the past twenty years. The technique is particularly suited for the identification of low atomic number elements, as nitrogen that is a main component of drugs and explosives. Identification of these substances is important in the context of humanitarian demining, and in the control of illicit traffic of drugs and explosives. As a good example of recycling of radioactive sources, a ^241Am-Be neutron source emitting 10^7neutron/s, that was not longer in use for other purposes at Ingeominas, was used to build a neutron irradiator that can be used to teach prompt gamma ray analysis, and other nuclear techniques. We irradiated individual samples, each about 4 gram, of three different elements: nitrogen in urea, silicon in milled rock, and cadmium in cadmium oxide. The prompt gamma rays emitted in the nuclear reactions ^112Cd (neutron,gamma) ^113Cd, ^28Si (neutron,gamma) ^29Si and ^14N (neutron,gamma) ^15N were identified using a well-type NaI (Tl) detector, connected to a multi-channel analyzer.

  18. Primary gamma rays. [resulting from cosmic ray interaction with interstellar matter

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.

    1974-01-01

    Within this galaxy, cosmic rays reveal their presence in interstellar space and probably in source regions by their interactions with interstellar matter which lead to gamma rays with a very characteristic energy spectrum. From the study of the intensity of the high energy gamma radiation as a function of galactic longitude, it is already clear that cosmic rays are almost certainly not uniformly distributed in the galaxy and are not concentrated in the center of the galaxy. The galactic cosmic rays appear to be tied to galactic structural features, presumably by the galactic magnetic fields which are in turn held by the matter in the arm segments and the clouds. On the extragalactic scale, it is now possible to say that cosmic rays are not universal at the density seen near the earth. The diffuse celestial gamma ray spectrum that is observed presents the interesting possibility of cosmological studies and possible evidence for a residual universal cosmic ray density, which is much lower than the present galactic cosmic ray density.

  19. Development and analysis for core power gamma thermometer adaptation

    SciTech Connect

    Ren-Tai Chiang; Leong, T.

    1996-12-31

    The gamma thermometer (GT) has gained increasing interest to replace the local power range monitor (LPRM) and the traversing in-core probe (TIP) as the core monitoring device in new boiling water reactor (BWR) designs. The number of GTs is designed between the number of LPRMs, 4, and the number of TIPs, 24, per string, but its optimal number is yet to be determined. The authors have modified the BWR core Simulator PANACEA for analyzing the core power GT adaptation and have compared the axial core-averaged relative power distributions and two thermal limits of the GT 8- and 12-point adaptations against those of the TIP 24-point adaptation.

  20. Treatment of Trochanteric Fractures with the Gamma3 Nail - Methodology and Early Results of a Prospective Consecutive Monitored Clinical Case Series

    PubMed Central

    A.C, Unger; E, Wilde; B, Kienast; C, Jürgens; A. P, Schulz

    2014-01-01

    Objectives: There is only sparse data on clinical results and complications of the third-generation Gamma nailing system (Gamma3, Stryker). Therefore, we started a large multi-centre case series in 2008. The aim of this paper is to present the study design and early results of a single arm of a prospective, consecutive, monitored, post-market follow-up evaluation of Gamma3 nails. Methods: From September 2009 to January 2012, 154 consecutive patients with an average age of 80 ± 1.43 years (50-99 years) and a trochanteric femoral fracture were included in the local arm of the trial. All patients that fulfilled the inclusion criteria were treated with a Gamma3 nail. Preoperative variables included age, gender, fracture classification, walking ability (Merle d’Aubigné score), daily activity level (retrospective Zuckerman score), ASA rating of operative risk, waiting time for operation, use of walker or crutches and body mass index (BMI). Skin-to-skin time, fluoroscopy time, blood loss, intraoperative complications and device information were recorded for each patient. Follow-up postoperative assessment was undertaken at 4, 12 and 24 months. Hip range of motion, pain around the hip and the tight, walking ability (Merle d’Aubigné score, Sahlgrenska mobility score) and management of daily life (Zuckerman score) were used to evaluate the outcome. Results: The descriptive data of age, gender, BMI, ASA classification, fracture type and skin-to-skin time is similar to other studies. Median fluoroscopy time was 62 seconds (range: 4-225 seconds) and significantly shorter in closed reductions. No intraoperative implant-related complication was recorded. A cut-out of the leg-screw during assessment period occurred in 2.6% patients (n = 4). At the 12-month assessment two (1.8%) non-unions were identified and two patients (1.8%) had broken the femoral shaft below the 180 mm nail after a fall. Analysis of the scores showed significantly declined mobility and activity in daily

  1. CAFNA{reg{underscore}sign}, coded aperture fast neutron analysis for contraband detection: Preliminary results

    SciTech Connect

    Zhang, L.; Lanza, R.C.

    1999-12-01

    The authors have developed a near field coded aperture imaging system for use with fast neutron techniques as a tool for the detection of contraband and hidden explosives through nuclear elemental analysis. The technique relies on the prompt gamma rays produced by fast neutron interactions with the object being examined. The position of the nuclear elements is determined by the location of the gamma emitters. For existing fast neutron techniques, in Pulsed Fast Neutron Analysis (PFNA), neutrons are used with very low efficiency; in Fast Neutron Analysis (FNS), the sensitivity for detection of the signature gamma rays is very low. For the Coded Aperture Fast Neutron Analysis (CAFNA{reg{underscore}sign}) the authors have developed, the efficiency for both using the probing fast neutrons and detecting the prompt gamma rays is high. For a probed volume of n{sup 3} volume elements (voxels) in a cube of n resolution elements on a side, they can compare the sensitivity with other neutron probing techniques. As compared to PFNA, the improvement for neutron utilization is n{sup 2}, where the total number of voxels in the object being examined is n{sup 3}. Compared to FNA, the improvement for gamma-ray imaging is proportional to the total open area of the coded aperture plane; a typical value is n{sup 2}/2, where n{sup 2} is the number of total detector resolution elements or the number of pixels in an object layer. It should be noted that the actual signal to noise ratio of a system depends also on the nature and distribution of background events and this comparison may reduce somewhat the effective sensitivity of CAFNA. They have performed analysis, Monte Carlo simulations, and preliminary experiments using low and high energy gamma-ray sources. The results show that a high sensitivity 3-D contraband imaging and detection system can be realized by using CAFNA.

  2. Preliminary Results of a Full Hauser-feshbach Simulation of the Prompt Neutron and Gamma Emission from Fission Fragments

    NASA Astrophysics Data System (ADS)

    Regniera, D.; Litaizea, O.; Serota, O.

    The prompt neutron and gamma emission from fission fragments are investigated through the Monte Carlo code FIFRELIN which is developed at the CEA Cadarache research center. In a previous release of the code, the de-excitation of the fragments was treated in a two steps process. First the emission of all the prompt neutrons was simulated using a Weisskopf spectrum for the distribution of their kinetic energy. In a second step, the excitation energy still available was dissipated by the fragments as an electromagnetic decay cascade. This paper presents a new procedure for fragment de-excitation using an Hauser-Feshbach treatment of prompt particles emission. The neutron/gamma competition is then accounted for during the whole cascade. Moreover, the neutron emission is now ruled by the transmission coefficients directly coming from an optical model calculation performed with TALYS-1.4. The implementation of these models in the code FIFRELIN is quickly highlighted. The results in terms of neutrons and gamma multiplicities and spectra for one simulation of a 252Cf spontaneous fission are emphasized. The neutron multiplicity experimental data are used to constraint the parameters of our simulation. The prompt gamma spectrum calculated is then consistent with experimental data and the structures observed experimentally in the low energy range are well reproduced. However, the same simulation performed with several different nuclear models and parameters reveals high variation of these fission observables. For example, the average total gamma energy (Eγ,tot) is shown to vary up to 20% with changes in the level density or radiative strength function model.

  3. Development of a database for prompt gamma-ray neutron activation analysis: Summary report of the third research coordination meeting

    SciTech Connect

    Lindstrom, Richard M.; Firestone, Richard B.; Pavi, ???

    2003-04-01

    The main discussions and conclusions from the Third Co-ordination Meeting on the Development of a Database for Prompt Gamma-ray Neutron Activation Analysis are summarized in this report. All results were reviewed in detail, and the final version of the TECDOC and the corresponding software were agreed upon and approved for preparation. Actions were formulated with the aim of completing the final version of the TECDOC and associated software by May 2003.

  4. Modeling particle acceleration and transport during high-energy solar gamma-ray events: Results from the HESPERIA project

    NASA Astrophysics Data System (ADS)

    Afanasiev, Alexandr; Battarbee, Markus; Vainio, Rami; Rouillard, Alexis; Aran, Angels; Sipola, Robert; Pomoell, Jens

    2016-04-01

    The EU/H2020 project "High Energy Solar Particle Events foRecastIng and Analysis" (HESPERIA) has an objective to gain improved understanding of solar energetic particle (SEP) acceleration, release and transport related to long-duration gamma-ray emissions recently observed by Fermi/LAT. We have performed simulation studies for particle acceleration and transport for the 17 May 2012 event, which is also a Ground Level Enhancement (GLE) of solar cosmic rays. The particle event is modeled assuming that it is accelerated by the shock wave driven by the erupting coronal mass ejection (CME). We first analyze the 3-dimensional propagation of the shock through the corona using imaging observations from SDO, SOHO and STEREO spacecraft. The derived kinematics of the shock is combined with magnetohydrodynamic and potential field modeling of the ambient corona to derive the evolution of the shock parameters on a large set of field lines. We then employ the self-consistent Coronal Shock Acceleration (CSA) simulation model of the University of Turku to study the acceleration process on selected field lines and combine it with a new model of downstream particle transport to assess the energy spectrum and time profile of accelerated particles precipitating in the dense surface regions below the corona. We also employ the Shock and Particle (SaP) simulation model of the University of Barcelona to analyze the interplanetary counterpart of the Fermi event. In this paper, we will present the observations of the event, our approach to the modeling and the first results of the analysis. The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA).

  5. Method for on-line evaluation of materials using prompt gamma ray analysis

    DOEpatents

    Akers, Douglas W.

    2009-12-08

    A method for evaluating a material specimen comprises: Mounting a neutron source and a detector adjacent the material specimen; bombarding the material specimen with neutrons from the neutron source to create prompt gamma rays within the material specimen, some of the prompt gamma rays being emitted from the material specimen, some of the prompt gamma rays resulting in the formation of positrons within the material specimen by pair production; collecting positron annihilation data by detecting with the detector at least one emitted annihilation gamma ray resulting from the annihilation of a positron; storing the positron annihilation data on a data storage system for later retrieval and processing; and continuing to collect and store positron annihilation data, the continued collected and stored positron annihilation data being indicative of an accumulation of lattice damage over time.

  6. The optimum Ga-67-citrate gamma camera imaging quality factors as first calculated and shown by the Taguchi's analysis.

    PubMed

    Yeh, Da Ming; Chang, Pai Jung; Pan, Lung Kwang

    2013-01-01

    In this work gallium-67 ((67)Ga) gamma camera imaging quality was optimized using the Taguchi's analysis and a planar phantom. The acrylic planar phantom was LASER-cut to form groups of slits 1mm wide and 5mm deep, to determine the spatial resolution and contrast ratio that could be achieved in a (67)Ga citrate nuclear medicine examination. The (67)Ga-citrate solution was injected into the slits to form an active radioactive line source which was placed between regular acrylic plates for optimization. Then, nine combinations of four operating factors: L9 (3((4)), of the gamma camera imaging system were used and followed the Taguchi's analysis. The four operating factors were: a) the type of collimator in front of the NaI(Tl) detector, b) the region of interest of (67)Ga gamma rays spectrum, c) the scanning speed of NaI(Tl) detector head and d) the activity of (67)Ga. The original judged grade of the planar phantom image quality was increased 36% and factors a) and b) were confirmed to dominate. The cross interaction among factors was also discussed. Our results showed that the optimal factor settings of the gamma camera imaging system were verified by performing a routine nuclear medicine examination in ten cases. Nine cases showed the same optimal settings as estimated by three highly trained radio-diagnostic physicians. Additionally, the optimal setting yielded clearer images with greater contrast than did the conventional settings. In conclusion, this work suggests for practical use an optimized process for determining both the spatial resolution and the contrast ratio of a gamma camera imaging system using Taguchi's optimal analysis and a planar phantom. The Taguchi's method is most effective in targeting a single quality characteristic but can also be extended to satisfy multiple requirements under specific conditions by revising the definition of signal to noise ratio. PMID:23529390

  7. Outcrop Gamma-ray Analysis of the Cretaceous mesaverde Group: Jicarilla Apache Indian Reservation, New Mexico

    SciTech Connect

    Ridgley, Jennie; Dunbar, Robyn Wright

    2001-04-25

    This report presents the results of an outcrop gamma-ray survey of six selected measured sections included in the original report. The primary objective of this second study is to provide a baseline to correlate from the outcrop and reservoir model into Mesaverde strata in the San Juan Basin subsurface. Outcrop logs were generated using a GAD-6 gamma-ray spectrometer that simultaneously recorded total counts, potassium, uranium, and thorium data.

  8. Analysis of AGS polarimeter data at G{gamma}=7.5.

    SciTech Connect

    Huang, H.; Cadman, R. V.; Spinka, H. M.; Underwood, D. G.

    2003-02-18

    Data were collected with the AGS internal polarimeter at G{gamma} = 7.5 during the recent FY02 polarized proton run. The addition of new forward scintillation counters permitted an absolute calibration of the polarimeter for both nylon and carbon targets. The results are summarized, and the polarization measured at G{gamma} = 7.5 is compared to that at 200 MeV.

  9. Analysis of T cell receptor-gamma gene rearrangements by denaturing gradient gel electrophoresis of GC-clamped polymerase chain reaction products. Correlation with tumor-specific sequences.

    PubMed Central

    Greiner, T. C.; Raffeld, M.; Lutz, C.; Dick, F.; Jaffe, E. S.

    1995-01-01

    We describe a modified denaturing gradient gel electrophoresis (DGGE) procedure with a 40-nucleotide GC clamp in the polymerase chain reaction to improve resolution in amplifying T cell receptor-gamma (TCR-gamma) rearrangements. DNA from 46 cases of lymphoblastic leukemia/lymphoma, 5T cell lines, 2 B cell lines, 7 normal lymphocytes, and 3 cases of Hodgkin's disease was amplified by polymerase chain reaction. In addition, 20 cases of paraffin-embedded T cell lymphomas and 5 cases of reactive hyperplasia were also studied. Clonal TCR-gamma rearrangements were identified on DGGE by the presence of a predominant band. Results obtained from 5 T cell lines and 12 lymphoblastic leukemia/lymphomas containing known TCR-gamma gene rearrangements revealed 100% concordance in detecting clonal rearrangements between DGGE and traditional Southern blot analysis. Of the remaining 34 lymphoblastic leukemia/lymphoma cases studied by DGGE alone, 30 were positive. DGGE analysis of 10 lymphoblastic leukemia/lymphoma cases with known group IV gamma to J gamma 1 or J gamma 2 rearrangement sequences confirmed that the electrophoretic migration was dependent on the tumor-specific rearranged TCR-gamma sequence. In addition, 17 of 20 cases of paraffin-embedded T cell lymphomas were positive by DGGE, 6 of which had the clonal population also identified in fresh tissue DNA. DGGE analysis of GC-clamped polymerase chain reaction products can provide a way to more accurately detect TCR-gamma clonality of lymphoid tumors and can be applied to archival tissues. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:7856738

  10. Identifiability of UHE Gamma-ray Air Showers by Neural-Network-Analysis

    NASA Astrophysics Data System (ADS)

    Wada, Y.; Inoue, N.; Miyazawa, K.; Vankov, H.P.

    The chemical composition of Ultra-High-Energy (UHE) comic rays is one of unsolved mysteries, and its study will give us fruitful information on the origin and acceleration mechanism of UHE cosmic rays. Especially, a detection of UHE gamma-rays by hybrid experiments, such as AUGER and TA, will be a key to solve these questions. The characteristics of UHE gamma-ray showers have been studied on lateral and longitudinal structure of shower particles by AIRES and our own simulation code, so far. There are apparent differences in a slope of lateral distribution (Eta) and a depth of shower maximum (Xmax) between gamma-ray and proton induced showers because UHE gamma-ray showers are affected by the LPM effect and the geomagnetic cascading process in an energy region of > 1019.5eV. Different features between gamma-ray and proton showers are pointed out from the simulation study and an identifiability of gamma-ray showers from proton ones is also discussed by the method of Neural-Network-Analysis.

  11. Comparison of cell repair mechanisms by means of chromosomal aberration induced by proton and gamma irradiation - preliminary results

    NASA Astrophysics Data System (ADS)

    Kowalska, A.; Czerski, K.; Kaczmarski, M.; Lewocki, M.; Masojć, B.; Łukowiak, A.

    2015-03-01

    DNA damage of peripheral blood lymphocytes exposed to gamma and proton irradiation is studied by means of chromosome aberrations to validate the efficiency of the repair mechanisms of individual cells. A new method based on an observed deviation from the Poisson statistics of the chromosome aberration number is applied for estimation of a repair factor ( RF) defined as a ratio between originally damaged cells to the amount of finally observed aberrations. The repair factors are evaluated by studying the variance of individual damage factors in a collective of healthy persons at a given dose as well as by using the chi-square analysis for the dose-effect curves. The blood samples from fifteen donors have been irradiated by Co60 gamma rays and from nine persons by 150 MeV protons with different doses up to 2 Gy. A standard extraction of lymphocyte has been used whereby dicentrics, acentrics and rings have been scored under a microscope. The RF values determined for the proton radiation are slightly larger than for gamma rays, indicating that up to 70% DNA double strand breaks can be repaired.

  12. Model-Independent Results for the Decay B \\to L Nu(L) Gamma at BaBar

    SciTech Connect

    Lindemann, D.M.; /McGill U.

    2012-04-09

    We present a search for the radiative leptonic decays B{sub +} {yields} e{sup +} {nu}{sub e}{gamma} and B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{gamma} using data collected by the BABAR detector at the PEP-II B factory. We fully reconstruct the hadronic decay of one of the B mesons in {Upsilon}(4S) {yields} B{sup +}B{sup -} and then search for evidence of the signal decay within the rest of the event. This method provides clean kinematic information on the signal's missing energy and high momentum photon and lepton, and allows for a model-independent analysis of this decay. Using a data sample of 465 million B-meson pairs, we obtain sensitivity to branching fractions of the same order as predicted by the Standard Model. We report a model-independent branching fraction upper limit of {Beta}(B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma}) < 15.6 x 10{sup -6} ({ell} = e or {mu}) at the 90% confidence level.

  13. Recent Results in Ring-Diagram Analysis

    NASA Astrophysics Data System (ADS)

    Rabello-Soares, M. C.

    2013-12-01

    The ring-diagram technique was developed by Frank Hill 25 years ago and matured quickly during the late 1990s. It is nowadays one of the most commonly used techniques in local helioseismology. The method consists in the power spectral analysis of solar acoustic oscillations on small regions (2° to 30°) of the solar surface. The power spectrum resembles a set of trumpets nested inside each other and for a given frequency, it looks like a ring, hence the technique's name. It provides information on the horizontal flow field and thermodynamic structure in the layers immediately below the photosphere. With data regularly provided by MDI, GONG, and more recently HMI, many important results have been achieved. In recently years, these results include estimations of the meridional circulation and its evolution with solar cycle; flows associated with active regions, as well as, flow divergence and vorticity, and thermal structure beneath and around active regions. Much progress is expected with data now provided by HMI's high spatial resolution observations and high duty cycle. There are two data processing pipelines (GONG and HMI) providing free access to the data and the results of the ring-diagram analysis. Here we will discuss the most recent results and improvements in the technique, as well as, the many challenges that still remain.

  14. Pulse-shape analysis for gamma background rejection in thermal neutron radiation using CVD diamond detectors

    NASA Astrophysics Data System (ADS)

    Kavrigin, P.; Finocchiaro, P.; Griesmayer, E.; Jericha, E.; Pappalardo, A.; Weiss, C.

    2015-09-01

    A novel technique for the rejection of gamma background from charged-particle spectra was demonstrated using a CVD diamond detector with a 6Li neutron converter installed at a thermal neutron beamline of the TRIGA research reactor at the Atominstitut (Vienna University of Technology). Spectra of the alpha particles and tritons of 6Li(n,T)4He thermal neutron capture reaction were separated from the gamma background by a new algorithm based on pulse-shape analysis. The thermal neutron capture in 6Li is already used for neutron flux monitoring, but the ability to remove gamma background allows using a CVD diamond detector for thermal neutron counting. The pulse-shape analysis can equally be applied to all cases where the charged products of an interaction are absorbed in the diamond and to other background particles that fully traverse the detector.

  15. Isotopic composition analysis and age dating of uranium samples by high resolution gamma ray spectrometry

    NASA Astrophysics Data System (ADS)

    Apostol, A. I.; Pantelica, A.; Sima, O.; Fugaru, V.

    2016-09-01

    Non-destructive methods were applied to determine the isotopic composition and the time elapsed since last chemical purification of nine uranium samples. The applied methods are based on measuring gamma and X radiations of uranium samples by high resolution low energy gamma spectrometric system with planar high purity germanium detector and low background gamma spectrometric system with coaxial high purity germanium detector. The "Multigroup γ-ray Analysis Method for Uranium" (MGAU) code was used for the precise determination of samples' isotopic composition. The age of the samples was determined from the isotopic ratio 214Bi/234U. This ratio was calculated from the analyzed spectra of each uranium sample, using relative detection efficiency. Special attention is paid to the coincidence summing corrections that have to be taken into account when performing this type of analysis. In addition, an alternative approach for the age determination using full energy peak efficiencies obtained by Monte Carlo simulations with the GESPECOR code is described.

  16. Three-dimensional gamma analysis of dose distributions in individual structures for IMRT dose verification.

    PubMed

    Tomiyama, Yuuki; Araki, Fujio; Oono, Takeshi; Hioki, Kazunari

    2014-07-01

    Our purpose in this study was to implement three-dimensional (3D) gamma analysis for structures of interest such as the planning target volume (PTV) or clinical target volume (CTV), and organs at risk (OARs) for intensity-modulated radiation therapy (IMRT) dose verification. IMRT dose distributions for prostate and head and neck (HN) cancer patients were calculated with an analytical anisotropic algorithm in an Eclipse (Varian Medical Systems) treatment planning system (TPS) and by Monte Carlo (MC) simulation. The MC dose distributions were calculated with EGSnrc/BEAMnrc and DOSXYZnrc user codes under conditions identical to those for the TPS. The prescribed doses were 76 Gy/38 fractions with five-field IMRT for the prostate and 33 Gy/17 fractions with seven-field IMRT for the HN. TPS dose distributions were verified by the gamma passing rates for the whole calculated volume, PTV or CTV, and OARs by use of 3D gamma analysis with reference to MC dose distributions. The acceptance criteria for the 3D gamma analysis were 3/3 and 2 %/2 mm for a dose difference and a distance to agreement. The gamma passing rates in PTV and OARs for the prostate IMRT plan were close to 100 %. For the HN IMRT plan, the passing rates of 2 %/2 mm in CTV and OARs were substantially lower because inhomogeneous tissues such as bone and air in the HN are included in the calculation area. 3D gamma analysis for individual structures is useful for IMRT dose verification. PMID:24796955

  17. Surface chemistry of Rh-Mo/{gamma}-Al{sub 2}O{sub 3}: An analysis of surface acidity

    SciTech Connect

    Lowenthal, E.E.; Schwarz, S.; Foley, H.C.

    1995-09-15

    This study highlights the nature of the interactions between the transition metals in the Rh-Mo/{gamma}-Al{sub 2}O{sub 3} system and the underlying alumina surface. The investigation was carried out in the context of exploring the retrograde dehydration to dimethyl ether of primary alcohols produced at active metal sites during CO hydrogenation. Both native {gamma}-Al{sub 2}O{sub 3} and Rh-Mo/{gamma}-Al{sub 2}O{sub 3} samples were doped with KNO{sub 3} in an attempt to create an alkaline-metal oxide layer on the support surface which would screen alcohols from underlying Lewis acidity. The samples were characterized by microreactor-based methanol dehydration studies, analysis of infrared spectra of adsorbed pyridine, and ammonia saturation and temperature-programmed desorption. As expected, the dehydration activity of the samples was strongly correlated to their potassium loading and, hence, their Lewis acidity. More intriguing, however, are the insights gained in this analysis concerning the nature of the interactions between Mo, Rh, and the Lewis acid sites on the alumina surface. Our results are consistent with the principle, suggested in the Mo/{gamma}-Al{sub 2}O{sub 3} literature, that our Mo(CO){sub 6} precursor interacts primarily with nonacidic hydroxyl groups on the dehydrated alumina surface. Furthermore, we provide strong evidence for the diminution of acidity brought on by the adsorption of Rh on Lewis acid sites of Mo/{gamma}-Al{sub 2}O{sub 3}. 30 refs., 9 figs., 1 tab.

  18. Morphometric analysis in gamma-ray astronomy using Minkowski functionals. Source detection via structure quantification

    NASA Astrophysics Data System (ADS)

    Göring, D.; Klatt, M. A.; Stegmann, C.; Mecke, K.

    2013-07-01

    Aims: H.E.S.S. observes an increasing number of large extended sources. A new technique based on the structure of the sky map is developed to account for these additional structures by comparing them with the common point source analysis. Methods: Minkowski functionals are powerful measures from integral geometry. They can be used to quantify the structure of the counts map, which is then compared with the expected structure of a pure Poisson background. Gamma-ray sources lead to significant deviations from the expected background structure. The standard likelihood ratio method is exclusively based on the number of excess counts and discards all further structure information of large extended sources. The morphometric data analysis incorporates this additional geometric information in an unbiased analysis, i.e., without the need of any prior knowledge about the source. Results: We have successfully applied our method to data of the H.E.S.S. experiment. The morphometric analysis presented here is dedicated to detecting faint extended sources.

  19. The Impact of Gamma Hydroxybutyrate (GHB) Legal Restrictions on Patterns of Use: Results from an International Survey

    PubMed Central

    Anderson, IB; Kim-Katz, SY; Dyer, JE; Blanc, PD

    2009-01-01

    Aims To conduct an Internet-based survey of GHB use, identifying differences by respondent residence. Methods We recruited GHB-knowledgeable persons via “social networking Internet sites.” Individuals (n=314) or groups (n=66) were approached based on GHB-use testimonials. Data collected location, use, reason for cessation (if applicable). Findings We recruited 155 GHB users. U.S. respondents (53 of 70; 76%) compared to non-U.S. respondents (38 of 85; 45%) were older and more highly educated (p<0.05) but manifest a 3-fold greater adjusted odds of GHB cessation (Odds Ratio [OR] 3.1; 95% CI 1.4–6.9; p < 0.05). Of the 80 respondents stating reason for cessation, 36 (45%) cited legal risk, price, or access; 44 (55%) cited health or related concerns. U.S. compared to non-U.S. respondents more frequently invoked legal and related concerns (OR 2.5; 95% CI 0.99–6.3; p=0.05). In a nested analysis, narrowly stated legal (n=4/5 U.S.) versus health (n=6/18 U.S.) reasons differed by location (p=0.048, one-tailed). Conclusions In the U.S., where GHB has stricter legal penalties, GHB cessation is more likely, with legal and related reasons more commonly invoked for cessation. These findings support a link between declining U.S. GHB abuse and more stringent restrictions; although other un-assessed factors may also explain this association. The Impact of Gamma Hydroxybutyrate (GHB) Legal Restrictions on Patterns of Use: Results from an International Survey PMID:20953310

  20. A Search for Nontriggered Gamma-Ray Bursts in the BATSE Continuous Records: First Results

    NASA Astrophysics Data System (ADS)

    Stern, B. E.; Tikhomirova, Ya.; Stepanov, M.; Kompaneets, D.; Berezhnoy, A.; Svensson, R.

    2000-09-01

    An off-line scan for nontriggered gamma-ray bursts (GRBs) in the BATSE daily records at 1024 ms time resolution covering about 7 yr of observations gave 1353 nontriggered and 1581 triggered GRBs. The scan efficiency was measured by adding artificial test bursts to the data. The logN-logP distribution could be extended down to peak fluxes, P~0.1 photons cm-2 s-1. Previous indications of a turnover at small P are not confirmed. The logN-logP distribution cannot be fitted with a standard candle model with a nonevolving GRB source population, assuming that there are no large non-GRB contaminations. It is likely that the intrinsic luminosity function of GRBs is wide.

  1. Results of a study to build a gamma-ray telescope in an external tank

    NASA Technical Reports Server (NTRS)

    Koch, D.

    1985-01-01

    In response to the ever-present need for a very large gamma-ray detector for energies greater than 100 MeV, a concept to build a telescope of 250,000 sq cm sensitive area using a Space Shuttle External Tank (ET) is presented. In the Space Station era, for the first time, large detectors can be constructed on-orbit which would otherwise be limited in size by the launch vehicle. The ET will serve both as the spacecraft and the Cherenkov pressure vessel. The significant feature is that the sensitive area will be forty times that of the high energy detector on GRO and will be able to locate even the faintest sources from the GRO survey to a few arc minutes. The detection technique is based upon that originally proposed by Greisen.

  2. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1992-01-01

    Miscellaneous tasks related to mission operations and data analysis for the Burst and Transient Source Experiment on the Gamma Ray Observatory, to collection, analysis, and interpretation of data from the Marshall Space Flight Center Very Low Frequency transient monitoring program, and to compilation and analysis of induced radioactivity data were performed. The results are summarized and relevant references are included.

  3. On Ultra-high-energy Cosmic Rays and Their Resultant Gamma-Rays

    NASA Astrophysics Data System (ADS)

    Gavish, Eyal; Eichler, David

    2016-05-01

    The Fermi Large Area Telescope collaboration has recently reported on 50 months of measurements of the isotropic extragalactic gamma-ray background (EGRB) spectrum between 100 MeV and 820 GeV. Ultra-high-energy cosmic ray (UHECR) protons interact with the cosmic microwave background photons and produce cascade photons of energies 10 MeV–1 TeV that contribute to the EGRB flux. We examine seven possible evolution models for UHECRs and find that UHECR sources that evolve as the star formation rate (SFR), medium low luminosity active galactic nuclei type-1 (L = 1043.5 erg s‑1 in the [0.5–2] KeV band), and BL Lacertae objects (BL Lacs) are the most acceptable given the constraints imposed by the observed EGRB. Other possibilities produce too much secondary γ-radiation. In all cases, the decaying dark matter (DM) contribution improves the fit at high energy, but the contribution of still unresolved blazars, which would leave the smallest role for decaying DM, may yet provide an alternative improvement. The possibility that the entire EGRB can be fitted with resolvable but not-yet-resolved blazars, as recently claimed by Ajello et al., would leave little room in the EGRB to accommodate γ-rays from extragalactic UHECR production, even for many source evolution rates that would otherwise be acceptable. We find that under the assumption of UHECRs being mostly protons, there is not enough room for producing extragalactic UHECRs with active galactic nucleus, gamma-ray burst, or even SFR source evolution. Sources that evolve as BL Lacs, on the other hand, would produce much less secondary γ-radiation and would remain a viable source of UHECRs, provided that they dominate.

  4. CHAMP Tracking and Accelerometer Data Analysis Results

    NASA Technical Reports Server (NTRS)

    Lemoine, Frank G.; Luthcke, S. B.; Rowlands, D. D.; Pavlis, D. E.; Colombo, O. L.; Ray, Richard D.; Thompson, B.; Nerem, R. S.; Williams, Teresa A.; Smith, David E. (Technical Monitor)

    2002-01-01

    The CHAMP (Challenging Minisatellite Payload) mission's unique combination of sensors and orbit configuration will enable unprecedented improvements in modeling and understanding the Earth's static gravity field and its temporal variations. CHAMP is the first of two missions (GRACE (Gravity Recovery and Climate Experiment) to be launched in the later part of '01) that combine a new generation of GPS (Global Positioning System) receivers, a high precision three axis accelerometer, and star cameras for the precision attitude determination. In order to isolate the gravity signal for science investigations, it is necessary to perform a detailed reduction and analysis of the GPS and SLR tracking data in conjunction with the accelerometer and attitude data. Precision orbit determination based on the GPS and SLR (Satellite Laser Ranging) tracking data will isolate the orbit perturbations, while the accelerometer data will be used to distinguish the surface forces from those due to the geopotential (static, and time varying). In preparation for the CHAMP and GRACE missions, extensive modifications have been made to NASA/GSFC's GEODYN orbit determination software to enable the simultaneous reduction of spacecraft tracking (e.g. GPS and SLR), three axis accelerometer and precise attitude data. Several weeks of CHAMP tracking and accelerometer data have been analyzed and the results will be presented. Precision orbit determination analysis based on tracking data alone in addition to results based on the simultaneous reduction of tracking and accelerometer data will be discussed. Results from a calibration of the accelerometer will be presented along with the results from various orbit determination strategies. Gravity field modeling status and plans will be discussed.

  5. High resolution gamma-ray spectroscopy applied to bulk sample analysis

    SciTech Connect

    Kosanke, K.L.; Koch, C.D.; Wilson, R.D.

    1980-01-01

    A high resolution Ge(Li) gamma-ray spectrometer has been installed and made operational for use in routine bulk sample analysis by the Bendix Field Engineering Corporation (BFEC) geochemical analysis department. The Ge(Li) spectrometer provides bulk sample analyses for potassium, uranium, and thorium that are superior to those obtained by the BFEC sodium iodide spectrometer. The near term analysis scheme permits a direct assay for uranium that corrects for bulk sample self-absorption effects and is independent of the uranium/radium disequilibrium condition of the sample. A more complete analysis scheme has been developed that fully utilizes the gamma-ray data provided by the Ge(Li) spectrometer and that more properly accounts for the sample self-absorption effect. This new analysis scheme should be implemented on the BFEC Ge(Li) spectrometer at the earliest date.

  6. Semiconductor arrays with multiplexer readout for gamma-ray imaging: results for a 48 × 48 Ge array

    NASA Astrophysics Data System (ADS)

    Barber, H. B.; Augustine, F. L.; Barrett, H. H.; Dereniak, E. L.; Matherson, K. L.; Meyers, T. J.; Perry, D. L.; Venzon, J. E.; Woolfenden, J. M.; Young, E. T.

    1994-12-01

    We are developing a new kind of gamma-ray imaging device that has sub-millimeter spatial resolution and excellent energy resolution. The device is composed of a slab of semiconductor detector partitioned into an array of detector cells by photolithography and connected to a monolithic circuit chip called a multiplexer (MUX) for readout. Our application is for an ultra-high-resolution SPECT system for functional brain imaging using an injected radiotracer. We report here on results obtained with a Hughes 48 × 48 Ge PIN-photodiode array with MUX readout, originally developed as an infrared focal-plane-array imaging sensor. The device functions as an array of individual gamma-ray detectors with minimal interpixel crosstalk. Linearity of energy response is excellent up to at least 140 keV. The array exhibits excellent energy resolution, ˜ 2 keV at ≤ 140 keV or 1.5% FWHM at 140 keV. The energy resolution is dominated by MUX readout noise and so should improve with MUX optimization for gamma-ray detection. The spatial resolution of the 48 × 48 Ge array is essentially the same as the pixel spacing, 125 μm. The quantum efficiency is limited by the thin Ge detector (0.25 mm), but this approach is readily applicable to thicker Ge detectors and room-temperature semiconductor detectors such as CdTe, HgI 2 and CdZnTe.

  7. Continuous versus pulse neutron induced gamma spectroscopy for soil carbon analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neutron induced gamma spectra analysis (NGA) provides a means of measuring carbon in large soil volumes without destructive sampling. Calibration of the NGA system must account for system background and the interference of other nuclei on the carbon peak at 4.43 MeV. Accounting for these factors pro...

  8. Documentation of the data analysis system for the gamma ray monitor aboard OSO-H

    NASA Technical Reports Server (NTRS)

    Croteau, S.; Buck, A.; Higbie, P.; Kantauskis, J.; Foss, S.; Chupp, D.; Forrest, D. J.; Suri, A.; Gleske, I.

    1973-01-01

    The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs.

  9. Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

    SciTech Connect

    Staples, P.; Prettyman, T.; Lestone, J.

    1998-12-01

    The authors have used a tomographic gamma scanner (TGS) to produce tomographic prompt gamma-ray neutron activation analysis imaging (PGNAA) of heterogeneous matrices. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. The authors are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis (NDA) technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source-to-sample coupling term. To assist in the determination of the coupling term, the authors have obtained images for a range of sample that are very well characterized, such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. They then compare the measurements to MCNP calculations. For an accurate quantitative measurement, it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes.

  10. PROTON INDUCED GAMMA-RAY ANALYSIS OF ATMOSPHERIC AEROSOLS FOR CARBON, NITROGEN, AND SULFUR COMPOSITION

    EPA Science Inventory

    A technique for the simultaneous quantitative analysis of carbon, nitrogen, and sulfur using in-beam gamma-ray spectrometry has been developed for use with atmospheric aerosol samples. Samples are collected on quartz filters, and the aerosol composition is determined by analyzing...

  11. Gamma Detector Response and Analysis Software%u2013Detector Response Function

    Energy Science and Technology Software Center (ESTSC)

    2015-04-01

    Version 00 GADRAS-DRF contains a suite of capabilities related to radiation detection. Its primary function is the simulation of gamma-ray and neutron detector signals to radiation sources. It also contains limited analysis functionality. GADRAS-DRF is the public version of the full version of GADRAS with capabilities such as radiation transport and advanced analyses removed.

  12. GC-MS Analysis of [gamma]-Hydroxybutyric Acid Analogs: A Forensic Chemistry Experiment

    ERIC Educational Resources Information Center

    Henck, Colin; Nally, Luke

    2007-01-01

    An upper-division forensic chemistry experiment is described. It involves using glycolic acid and sodium glycolate as analogs of [gamma]-hydroxybutyric acid and its sodium salt. The experiment shows the use of silylation in GC-MS analysis and gives students the opportunity to work with a commonly used silylating reagent,…

  13. Searching for Variability in the Gamma-ray Sky using the Fermi All-sky Variability Analysis (FAVA)

    NASA Astrophysics Data System (ADS)

    Kocevski, Daniel; Buehler, Rolf; Ajello, Marco; Giomi, Matteo; Fermi LAT Collaboration

    2016-01-01

    We present the results of the second Fermi All-sky Variability Analysis (FAVA) catalog, consisting of a search for week long variability above 100 MeV using the new Pass 8 data selection. The catalog includes over 2000 flares, spanning 6 years of the Fermi mission, with hundreds of flares that are not associated with any known catalog source. FAVA was designed to efficiently search for variable sources over a wide range of energies and timescales. Unlike a traditional likelihood analysis, the analysis performed by FAVA uses the mission averaged emission as a background, and is as such independent of any model for the diffuse gamma-ray emission. This makes the FAVA analysis especially sensitive to variable sources in the Galactic plane. This analysis is also computationally inexpensive, allowing for blind searches for flux variations over the entire sky. We will present some of the interesting flares identified through this analysis, and highlight those that are typically missed through traditional analysis methods. We will also present the new public FAVA webpage, which is designed to alert the community of new gamma-ray flares in real time and allow users to create relative flux light curves for any position on the sky; a task that is currently computationally intensive to perform over long intervals using traditional analysis tools.

  14. X-ray fluorescence and gamma-ray spectrometry combined with multivariate analysis for topographic studies in agricultural soil.

    PubMed

    de Castilhos, Natara D B; Melquiades, Fábio L; Thomaz, Edivaldo L; Bastos, Rodrigo Oliveira

    2014-10-15

    Physical and chemical properties of soils play a major role in the evaluation of different geochemical signature, soil quality, discrimination of land use type, soil provenance and soil degradation. The objectives of the present study are the soil elemental characterization and soil differentiation in topographic sequence and depth, using Energy Dispersive X-Ray Fluorescence (EDXRF) as well as gamma-ray spectrometry data combined with Principal Component Analysis (PCA). The study area is an agricultural region of Boa Vista catchment which is located at Guamiranga municipality, Brazil. PCA analysis was performed with four different data sets: spectral data from EDXRF, spectral data from gamma-ray spectrometry, concentration values from EDXRF measurements and concentration values from gamma-ray spectrometry. All PCAs showed similar results, confirmed by hierarchical cluster analysis, allowing the data grouping into top, bottom and riparian zone samples, i.e. the samples were separated due to its landscape position. The two hillslopes present the same behavior independent of the land use history. There are distinctive and characteristic patterns in the analyzed soil. The methodologies presented are promising and could be used to infer significant information about the region to be studied. PMID:25464179

  15. An Analysis Methodology for the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Morris, Robin D.; Cohen-Tanugi, Johann

    2004-01-01

    The Large Area Telescope (LAT) instrument on the Gamma Ray Large Area Space Telescope (GLAST) has been designed to detect high-energy gamma rays and determine their direction of incidence and energy. We propose a reconstruction algorithm based on recent advances in statistical methodology. This method, alternative to the standard event analysis inherited from high energy collider physics experiments, incorporates more accurately the physical processes occurring in the detector, and makes full use of the statistical information available. It could thus provide a better estimate of the direction and energy of the primary photon.

  16. Gamma Detector Response and Analysis Software (GADRAS) v. 16.0

    Energy Science and Technology Software Center (ESTSC)

    2009-12-24

    GADRAS is a general purpose application for the modeling and analysis of radiation detector responses, primarily gamma spectroscopic instruments and neutron detectors based on proportional counters. It employs radiation source and detector response models to predict the response of user-defined detectors to user-defined sources. It implements methods to identify radiation sources from their measured signatures, primarily the measured gamma spectrum and neutron count rate. Radiation source emissions are calculated using analytical and numerical radiation transportmore » models. Detector responses are calculated using point models of the detector material, dimensions, collimation, and scattering environment. Analytical methods are implemented using linear and nonlinear regression techniques.« less

  17. Gamma Detector Response and Analysis Software (GADRAS) v. 16.0

    SciTech Connect

    Mitchell, Dean; & Mattingly, John

    2009-12-24

    GADRAS is a general purpose application for the modeling and analysis of radiation detector responses, primarily gamma spectroscopic instruments and neutron detectors based on proportional counters. It employs radiation source and detector response models to predict the response of user-defined detectors to user-defined sources. It implements methods to identify radiation sources from their measured signatures, primarily the measured gamma spectrum and neutron count rate. Radiation source emissions are calculated using analytical and numerical radiation transport models. Detector responses are calculated using point models of the detector material, dimensions, collimation, and scattering environment. Analytical methods are implemented using linear and nonlinear regression techniques.

  18. Gamma-ray pulse height spectrum analysis on systems with multiple Ge detectors using spectrum summing

    SciTech Connect

    Killian, E.W.

    1997-11-01

    A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radionuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radio-nuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogeneous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in each individual spectrum are poor. The spectrum summing technique adds the spectra collected by each detector into a single spectrum which has better counting statistics than each individual spectrum. A normal spectral analysis program can then be used to analyze the sum spectrum to obtain radio-nuclide values which have smaller errors and do not have to be further manipulated to obtain results for the total waste container. 2 refs., 2 figs.

  19. Enhanced Analysis Techniques for an Imaging Neutron and Gamma Ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Madden, Amanda C.

    The presence of gamma rays and neutrons is a strong indicator of the presence of Special Nuclear Material (SNM). The imaging Neutron and gamma ray SPECTrometer (NSPECT) developed by the University of New Hampshire and Michigan Aerospace corporation detects the fast neutrons and prompt gamma rays from fissile material, and the gamma rays from radioactive material. The instrument operates as a double scatter device, requiring a neutron or a gamma ray to interact twice in the instrument. While this detection requirement decreases the efficiency of the instrument, it offers superior background rejection and the ability to measure the energy and momentum of the incident particle. These measurements create energy spectra and images of the emitting source for source identification and localization. The dual species instrument provides superior detection than a single species alone. In realistic detection scenarios, few particles are detected from a potential threat due to source shielding, detection at a distance, high background, and weak sources. This contributes to a small signal to noise ratio, and threat detection becomes difficult. To address these difficulties, several enhanced data analysis tools were developed. A Receiver Operating Characteristic Curve (ROC) helps set instrumental alarm thresholds as well as to identify the presence of a source. Analysis of a dual-species ROC curve provides superior detection capabilities. Bayesian analysis helps to detect and identify the presence of a source through model comparisons, and helps create a background corrected count spectra for enhanced spectroscopy. Development of an instrument response using simulations and numerical analyses will help perform spectra and image deconvolution. This thesis will outline the principles of operation of the NSPECT instrument using the double scatter technology, traditional analysis techniques, and enhanced analysis techniques as applied to data from the NSPECT instrument, and an

  20. 2015 Long-Term Hydrologic Monitoring Program Sampling and Analysis Results at Rio Blanco, Colorado

    SciTech Connect

    Findlay, Rick; Kautsky, Mark

    2015-12-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 20–21, 2015. This report documents the analytical results of the Rio Blanco annual monitoring event, the trip report, and the data validation package. The groundwater and surface water monitoring samples were shipped to the GEL Group Inc. laboratories for conventional analysis of tritium and analysis of gamma-emitting radionuclides by high-resolution gamma spectrometry. A subset of water samples collected from wells near the Rio Blanco site was also sent to GEL Group Inc. for enriched tritium analysis. All requested analyses were successfully completed. Samples were collected from a total of four onsite wells, including two that are privately owned. Samples were also collected from two additional private wells at nearby locations and from nine surface water locations. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry, and they were analyzed for tritium using the conventional method with a detection limit on the order of 400 picocuries per liter (pCi/L). Four locations (one well and three surface locations) were analyzed using the enriched tritium method, which has a detection limit on the order of 3 pCi/L. The enriched locations included the well at the Brennan Windmill and surface locations at CER-1, CER-4, and Fawn Creek 500 feet upstream.

  1. Gamma-ray and neutron radiography as part of a pulsed fast neutron analysis inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, J.; Bendahan, J.; Gozani, T.; Loveman, R.; Stevenson, J.; Bell, C.

    1999-02-01

    A gamma-ray and neutron radiography system has been developed to provide useful supplemental information for a Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. PFNA uses a collimated beam of pulsed neutrons to interrogate cargoes using (n, γx) reactions. The PFNA source produces both gamma rays as well as neutrons. The transmission of both species through the cargo is measured with an array of plastic scintillators. Since the neutron and gamma-ray signals are easily separated by arrival time a separate image can be made for both species. The radiography measurement is taken simultaneously with the PFNA measurement turning PFNA into an emission and transmission imaging system, thus enhancing the PFNA radiography system.

  2. Prompt gamma-ray analysis of chlorine in superpozz cement concrete

    NASA Astrophysics Data System (ADS)

    Naqvi, A. A.; Kalakada, Zameer; Al-Matouq, Faris A.; Maslehuddin, M.; Al-Amoudi, O. S. B.; ur-Rehman, Khateeb

    2012-11-01

    The chlorine concentration in Superpozz (SPZ) cement concrete was analyzed using a newly designed prompt gamma-ray neutron activation (PGNAA) setup utilizing a portable neutron generator. The setup, which mainly consists of a neutron source along with its moderator placed side by side with a shielded gamma-ray detector, allows determining chloride concentration in a concrete structure from one side. The setup has been tested through chlorine detection in chloride-contaminated Superpozz (SPZ) cement concrete specimens using 6.11 and 2.86±3.10 MeV chlorine prompt gamma-rays. The optimum 0.032±0.012 wt% value of Minimum Detectable Concentration (MDC) of chlorine in SPZ cement concrete measured in this study shows a successful application of a portable neutron generator in chloride analysis of concrete structure for corrosion studies.

  3. Geothermal industry employment: Survey results & analysis

    SciTech Connect

    Not Available

    2005-09-01

    The Geothermal Energy Association (GEA) is ofteh asked about the socioeconomic and employment impact of the industry. Since available literature dealing with employment involved in the geothermal sector appeared relatively outdated, unduly focused on certain activities of the industry (e.g. operation and maintenance of geothermal power plants) or poorly reliable, GEA, in consultation with the DOE, decided to conduct a new employment survey to provide better answers to these questions. The main objective of this survey is to assess and characterize the current workforce involved in geothermal activities in the US. Several initiatives have therefore been undertaken to reach as many organizations involved in geothermal activities as possible and assess their current workforce. The first section of this document describes the methodology used to contact the companies involved in the geothermal sector. The second section presents the survey results and analyzes them. This analysis includes two major parts. The first part analyzes the survey responses, presents employment numbers that were captured and describes the major characteristics of the industry that have been identified. The second part of the analysis estimates the number of workers involved in companies that are active in the geothermal business but did not respond to the survey or could not be reached. Preliminary conclusions and the study limits and restrictions are then presented. The third section addresses the potential employment impact related to manufacturing and construction of new geothermal power facilities. Indirect and induced economic impacts related with such investment are also investigated.

  4. Recent ADI iteration analysis and results

    SciTech Connect

    Wachspress, E.L.

    1994-12-31

    Some recent ADI iteration analysis and results are discussed. Discovery that the Lyapunov and Sylvester matrix equations are model ADI problems stimulated much research on ADI iteration with complex spectra. The ADI rational Chebyshev analysis parallels the classical linear Chebyshev theory. Two distinct approaches have been applied to these problems. First, parameters which were optimal for real spectra were shown to be nearly optimal for certain families of complex spectra. In the linear case these were spectra bounded by ellipses in the complex plane. In the ADI rational case these were spectra bounded by {open_quotes}elliptic-function regions{close_quotes}. The logarithms of the latter appear like ellipses, and the logarithms of the optimal ADI parameters for these regions are similar to the optimal parameters for linear Chebyshev approximation over superimposed ellipses. W.B. Jordan`s bilinear transformation of real variables to reduce the two-variable problem to one variable was generalized into the complex plane. This was needed for ADI iterative solution of the Sylvester equation.

  5. Gap analysis: Concepts, methods, and recent results

    USGS Publications Warehouse

    Jennings, M.D.

    2000-01-01

    Rapid progress is being made in the conceptual, technical, and organizational requirements for generating synoptic multi-scale views of the earth's surface and its biological content. Using the spatially comprehensive data that are now available, researchers, land managers, and land-use planners can, for the first time, quantitatively place landscape units - from general categories such as 'Forests' or 'Cold-Deciduous Shrubland Formation' to more categories such as 'Picea glauca-Abies balsamea-Populus spp. Forest Alliance' - in their large-area contexts. The National Gap Analysis Program (GAP) has developed the technical and organizational capabilities necessary for the regular production and analysis of such information. This paper provides a brief overview of concepts and methods as well as some recent results from the GAP projects. Clearly, new frameworks for biogeographic information and organizational cooperation are needed if we are to have any hope of documenting the full range of species occurrences and ecological processes in ways meaningful to their management. The GAP experience provides one model for achieving these new frameworks.

  6. Analysis of gamma-ray dosimetry experiments in the zero power MINERVE facility

    SciTech Connect

    Amharrak, H.; Di Salvo, J.; Lyoussi, A.; Roche, A.; Masson-Fauchier, M.; Bosq, J. C.; Carette, M.

    2011-07-01

    The objective of this study is to develop nuclear heating measurement methods in zero power experimental reactors. These developments contribute to the qualification of photonics calculation schemes for the assessment of gamma heating in the future Jules Horowitz Material Testing Reactor. This paper presents the analysis of thermoluminescent detector (TLD) experiments in the UO{sub 2} core of the MINERVE Research Reactor at the French Alternative Energies and Atomic Energy Commission center in Cadarache. The experimental sources of uncertainty in the gamma dose have been reduced by improving the measurement conditions and the repeatability of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account the calculation of cavity correction factors related to calibration and irradiation configurations, as well as neutron correction calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. The comparison between calculated and measured integral gamma-ray absorbed doses in the aluminum material surrounding the TLD shows that calculations slightly overestimate the measurement, with a calculated versus experimental ratio equal to 1.04 {+-} 5.7 % (k=2). (authors)

  7. SPECTRAL ANALYSIS AND INTERPRETATION OF THE {gamma}-RAY EMISSION FROM THE STARBURST GALAXY NGC 253

    SciTech Connect

    Abramowski, A.; Acero, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Brucker, J.; Barnacka, A.; Becherini, Y.; Birsin, E.; Biteau, J.; Brun, F.; Bolmont, J.; Brun, P.; Collaboration: H.E.S.S. Collaboration; and others

    2012-10-01

    Very high energy (VHE; E {>=} 100 GeV) and high-energy (HE; 100 MeV {<=} E {<=} 100 GeV) data from {gamma}-ray observations performed with the H.E.S.S. telescope array and the Fermi-LAT instrument, respectively, are analyzed in order to investigate the non-thermal processes in the starburst galaxy NGC 253. The VHE {gamma}-ray data can be described by a power law in energy with differential photon index {Gamma} = 2.14 {+-} 0.18{sub stat} {+-} 0.30{sub sys} and differential flux normalization at 1 TeV of F{sub 0} = (9.6 {+-} 1.5{sub stat}(+ 5.7, -2.9){sub sys}) Multiplication-Sign 10{sup -14} TeV{sup -1} cm{sup -2} s{sup -1}. A power-law fit to the differential HE {gamma}-ray spectrum reveals a photon index of {Gamma} 2.24 {+-} 0.14{sub stat} {+-} 0.03{sub sys} and an integral flux between 200 MeV and 200 GeV of F(0.2-200 GeV) = (4.9 {+-} 1.0{sub stat} {+-} 0.3{sub sys}) Multiplication-Sign 10{sup -9} cm{sup -2} s{sup -1}. No evidence for a spectral break or turnover is found over the dynamic range of both the LAT instrument and the H.E.S.S. experiment: a combined fit of a power law to the HE and VHE {gamma}-ray data results in a differential photon index {Gamma} = 2.34 {+-} 0.03 with a p-value of 30%. The {gamma}-ray observations indicate that at least about 20% of the energy of the cosmic rays (CRs) capable of producing hadronic interactions is channeled into pion production. The smooth alignment between the spectra in the HE and VHE {gamma}-ray domain suggests that the same transport processes dominate in the entire energy range. Advection is most likely responsible for charged particle removal from the starburst nucleus from GeV to multiple TeV energies. In a hadronic scenario for the {gamma}-ray production, the single overall power-law spectrum observed would therefore correspond to the mean energy spectrum produced by the ensemble of CR sources in the starburst region.

  8. Kinetic analysis of the thermal decomposition of pristine and gamma-irradiated zinc uranyl acetate

    NASA Astrophysics Data System (ADS)

    Al-Muhaimid, T. I. A.; Al-Qunaibit, M. H.; Al-Farhan, K. A.; Mahfouz, R. M.

    2004-11-01

    Thermal decomposition of pristine and gamma-irradiated zinc uranyl acetate was investigated in air using isothermal and dynamic thermogravimetric techniques. The decomposition proceeded via one major process with the formation of triuranates ZnU3O10 as solid residues. Kinetic analysis of isothermal data, when compared with various solid-state reaction models, showed that the decomposition reaction is best fitted by the phase-boundary model. Kinetic analysis of the cynamic TG curves was discussed with reference to integral methods of modified Coats and Redfern equations. Kinetic and thermodynamic parameters were calculated and evaluated. IR spectroscopy and X-ray powder diffraction techniques were employed to follow the chemical composition of solid residue at different calcination temperatures. The results display that the triuranate ZnU3O10 starts forming by calcination of zinc uranyl acetate at temperatures >300 degrees C and undergoes decomposition at higher temperatures (>600 degrees C) with the formation Of U3O8. The results were evaluated regarding the utilization of zinc uranyl acetate as an important source of diuranates and triuranates.

  9. Molecular cloning, characterization and expression analysis of PPAR gamma in the orange-spotted grouper (Epinephelus coioides) after the Vibrio alginolyticus challenge.

    PubMed

    Luo, Shengwei; Huang, Youhua; Xie, Fuxing; Huang, Xiaohong; Liu, Yuan; Wang, Weina; Qin, Qiwei

    2015-04-01

    PPAR gamma was a key nuclear receptor, playing an important role in the immune defense and the anti-inflammatory mechanism. In this study, the full-length PPAR gamma (EcPPAR gamma) was obtained, containing a 5'UTR of 133 bp, an ORF of 1602 bp and a 3'UTR of 26 bp besides the poly (A) tail. The EcPPAR gamma gene encoded a protein of 533 amino acids with an estimated molecular mass of 60.02 KDa and a predicted isoelectric point (pI) of 6.26. The deduced amino acid sequence showed that EcPPAR gamma consisted of the conserved residues and the domains known to be critical for the PPAR gamma function. The quantitative real-time PCR analysis revealed that EcPPAR gamma transcript was expressed in all the examined tissue, while the strong expression was observed in intestine, followed by the expression in liver, gill, spleen heart, kidney and muscle. Vibrio challenge could stimulate the inflammatory response in grouper and induce a sharp increase of pro-inflammatory cytokines expression, lipid peroxidation and DNA damage, while the up-regulation of vibrio-induced inflammation could also increase the non-specific immune defense. The groupers challenged with Vibrio alginolyticus showed a sharp increase of EcPPAR gamma transcript in immune tissues. Subcellular localization analysis revealed that EcPPAR gamma was distributed in the nucleus. Furthermore, overexpression of EcPPAR gamma could down-regulated the expression of IL1b, IL6, TNF1 and TNF2. In addition, the administration of PPAR gamma antagonist, GW9662, could up-regulate the expression of pro-inflammatory genes, including IL1b, IL6, TNF1 and TNF2. Together, these results indicated that EcPPAR gamma serving as a negative regulator of pro-inflammatory cytokines may play an important role in the immune defense against vibrio-induced inflammation in grouper. PMID:25592876

  10. Natural Time Analysis of Seismicity: Recent Results

    NASA Astrophysics Data System (ADS)

    Varotsos, P.; Uyeda, S.; Sarlis, N. V.; Skordas, E. S.; Nagao, T.; Kamogawa, M.

    2013-12-01

    Natural time analysis introduced almost a decade ago[1] may uncover novel dynamic features hidden in the time series of complex systems and has been applied[2] to diverse fields. For a time series comprising N events, the natural time for the occurrence of the k-th event of energy Qk is defined by χk=k/N and the analysis is made by studying the evolution of the pair (χk,pk ), where pk=Qk/ΣQn is the normalized energy. In natural time analysis of seismicity, the variance κ1 of natural time χ weighted for pk calculated from seismic catalogues serves as an order parameter [2]. The Japan seismic catalog was analyzed in natural time by employing a sliding natural time window of fixed length comprised of the number of events that would occur in a few months. This is a crucial time scale since it corresponds to the average lead time of the observed Seismic Electric Signals (SES) activities [2]. The following results are obtained: First, the fluctuations of the order parameter of seismicity exhibit [3] a clearly detectable minimum approximately at the time of the initiation of the pronounced SES activity observed [4] almost two months before the onset of the volcanic-seismic swarm activity in 2000 in the Izu Island region, Japan. This is the first time that before the occurrence of major earthquakes, anomalous changes are found to appear almost simultaneously in two different geophysical observables. Second, these two phenomena were shown to be also linked in space[3]. Third, minima of the order parameter fluctuations of seismicity were observed [5] a few months before all shallow earthquakes of magnitude 7.6 or larger that occurred from 1 January 1984 to 11 March 2011 (the day of the M9 Tohoku earthquake) in Japanese area. Among these minima, the minimum before the M9 Tohoku earthquake was the deepest. Additional recent results are forwarded which shed more light on the importance of the aforementioned minima for earthquake prediction purposes. [1] Varotsos, P. A

  11. New method of analysis for TeV gamma-ray data collected by the TACTIC telescope

    NASA Astrophysics Data System (ADS)

    Krishen, Chand

    2016-08-01

    We describe a new fractal and wavelet based framework for analysing atmospheric Cerenkov images of extensive air showers. The methodology developed using simulated data has been tested with the data collected from Mrk421 and Crab nebula directions during 10 October 2009-16 May 2010 by the TACTIC telescope. The telescope detected flaring activity in TeV gamma-rays from Mrk421 during 15th-17th February 2010. Hillas parameter analysis of Cerenkov images showed presence of TeV γ-ray signal with statistical significance of 12.5 σ beyond 1TeV energy for the 265 hours data set. Based on a Monte-Carlo simulated database of Cerenkov images recorded by the TACTIC telescope, the wavelet dimension B6 can be exploited as a useful parameter to segregate gamma-ray initiated events from hadron initiated events with better efficiency. We derive a preliminary value of the relevant significance for gamma initiated events using wavelet parameter B6 for the 265 hours long observation spell of Mrk421 including the flaring episode during 15th-17th February 2010 and 66 hours data of observations on Crab nebula. Wavelet analysis approach has also been tested on Crab OFF- source data of 27 hours. Application of wavelet parameter B6 on the recorded Cerenkov images of the TACTIC telescope reveals better results in terms of segregation efficiency and enhancement of the determined value of statistical significance as compared to the Hillas parameters approach.

  12. Results from the Third RHESSI Catalog of Terrestrial Gamma-ray Flashes

    NASA Astrophysics Data System (ADS)

    Smith, D. M.; Buzbee, P.; Infanger, A.; Dwyer, J. R.; Cummer, S. A.; Lu, G.; Holzworth, R. H.; Hutchins, M. L.; Splitt, M. E.; Lazarus, S. M.; Gjesteland, T.; Ostgaard, N.

    2013-12-01

    We present a new catalog of terrestrial gamma-ray flashes (TGFs) from the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) satellite. The new catalog includes a large set of new events not detected by either the original algorithm (Grefenstette et al. 2009 JGR 114, A02314) or the more sensitive algorithm of Gjesteland et al. 2012 (GRL 39, L05102). In the new algorithm, searches are conducted separately at time scales of 60, 100, and 300 microseconds and 1, 3, 10, and 30 milliseconds (the original catalog searched only at 1 millisecond binning of the counts). We will discuss the differences between TGFs of different duration in terms of geographical distribution, detailed characteristics of radio sferics observed by the Duke University sensors, and rate of matches with sferics detected by the World Wide Lightning Location Network (WWLLN). We will report in depth on the rare events occurring over the continental United States and off its eastern seaboard, where the expected height of the tropopause is generally lower than the expected production height of TGFs detected from orbit. In addition, we will present detailed modeling of the two bright TGF electron-beam events observed by RHESSI, over northern Africa on 2004 January 17 and over the eastern Mediterranean on 2013 January 18. The new algorithm, using its 10 ms and 30 ms time scales, should be sensitive to such events at a much lower brightness, but has not begun to detect such a population as of this writing. We will present any new events of this type that appear at higher sensitivity, and speculate on why they seem to be so difficult to detect.

  13. COHN analysis: Body composition measurements based on the associated particle imaging and prompt-gamma neutron activation analysis techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The measurement of the body's carbon (C), oxygen (O), hydrogen (H), and nitrogen (N) content can be used to calculate the relative amounts of fat, protein, and water. A system based on prompt-gamma neutron activation analysis (PGNAA), coupled with the associated particle imaging (API) technique, is...

  14. Gamma ray emission from spheres pulsed with D-T neutrons: Results of May 1987 experiments at RTNS-1

    SciTech Connect

    Goldberg, E.; Hansen, L.F.; Howerton, R.J.; Komoto, T.T.; Pohl, B.A.

    1987-11-01

    Subsequent to the analysis of the June 1986 series of experiments at RTNS-1, we thought it sensible to repeat some of the experiments with greater care given to the high energy portions of the effluent gamma ray spectra. In addition, some new materials were recommended for study, such as silicon. And since among our earlier experiments we observed data which was not highly reproducible, repeated runs would provide a quantitative assessment of the precision of the experiments. Accordingly, we followed the procedure outlined in UCID-20884. First, we calibrated the NE-213 detector with standard gamma ray sources and checked for linearity of pulse height with energy deposited by electrons. We then conducted experiments at RTNS-1, using spherical configurations of C, Si, Al, H/sub 2/O, N/sub 2/,Ti, Fe, and C/sub 2/F/sub 4/. The H/sub 2/O was contained in a modified glass flask, while the liquid nitrogen was held in a double-walled steel dewar. 25 refs., 17 figs., 9 tabs.

  15. Gamma Spectra Resulting From the Annihilation of Positrons with Electrons in Single, Selected Core Levels of Cu, Ag and Au

    SciTech Connect

    Kim, S; Eshed, A; Goktepeli, S; Sterne, P A; Koymen, A R; Chen, W C; Weiss, A H

    2005-07-25

    The {gamma}-ray energy spectra due to positron annihilation with the 3p core-level of Cu, the 4p core-level of Ag, and 5p core level of Au were obtained separately from the total annihilation spectrum by measuring the energies of {gamma}-rays time coincident with Auger electrons emitted as a result of filling the core-hole left by annihilation. The results of these measurements are compared to the total annihilation spectra and with LDA based theoretical calculations. A comparison of area normalized momentum distributions with the individual cores extracted from the Doppler measurements shows good qualitative agreement, however, in all three spectra, the calculated values of the momentum density appears to fall below the measured values as the momentum increases. The discrepancies between theory and experiment are well outside the statistical uncertainties of the experiment and become more pronounced with increasing Z going down the column from Cu to Ag to Au. The comparison with the experimental results clearly indicates that the calculations are not predicting the correct ratio of high momentum to low momentum spectral weight and suggest the need to improve the treatment of many body electron-positron correlation effects in annihilation as they pertain to core levels.

  16. Multi-componenet diffusion analysis and assessment of Gamma code and improved RELAP5 code

    SciTech Connect

    Chang Oh

    2007-05-01

    A loss-of-coolant accident (LOCA) has been considered a critical event for very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break by molecular diffusion and ultimately by natural convection leading to oxidation of the in-core graphite structure. Thus, without any mitigating features, a LOCA will lead to an air ingress event, which will lead to exothermic chemical reactions of graphite with oxygen, potentially resulting in significant increases of the core temperature. New and safer nuclear reactors (Generation IV) are now in the early planning stages in many countries throughout the world. One of the reactor concepts being seriously considered is the VHTR. To achieve public acceptance, these reactor concepts must show an increased level of inherent safety over current reactor designs (i.e., a system must be designed to eliminate any concerns of large radiological releases outside the site boundary). A computer code developed from this study, gas multi-component mixture analysis (GAMMA) code, was assessed using a two-bulb experiment and in addition the molecular diffusion behavior in the prismatic-core gas-cooled reactor was investigated following the guillotine break of the main pipe between the reactor vessel and the power conversion unit. The RELAP5 code was improved for the VHTR air ingress analysis and was assessed using inverse U-tube and NACOK natural circulation data.

  17. USEPA EXAMPLE EXIT LEVEL ANALYSIS RESULTS

    EPA Science Inventory

    Developed by NERL/ERD for the Office of Solid Waste, the enclosed product provides an example uncertainty analysis (UA) and initial process-based sensitivity analysis (SA) of hazardous waste "exit" concentrations for 7 chemicals and metals using the 3MRA Version 1.0 Modeling Syst...

  18. Portable microcomputer for the analysis of plutonium gamma-ray spectra. Volume I. Data analysis methodology and hardware description

    SciTech Connect

    Ruhter, W.D.

    1984-05-01

    A portable microcomputer has been developed and programmed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra. The unit includes a 16-bit LSI-11/2 microprocessor, 32-K words of memory, a 20-character display for user prompting, a numeric keyboard for user responses, and a 20-character thermal printer for hard-copy output of results. The unit weights 11 kg and had dimensions of 33.5 x 30.5 x 23.0 cm. This compactness allows the unit to be stored under an airline seat. Only the positions of the 148-keV /sup 241/Pu and 208-keV /sup 237/U peaks are required for spectral analysis that gives plutonium isotopic ratios and weight percent abundances. Volume I of this report provides a detailed description of the data analysis methodology, operation instructions, hardware, and maintenance and troubleshooting. Volume II describes the software and provides software listings.

  19. Empirical evidence and stability analysis of the linear car-following model with gamma-distributed memory effect

    NASA Astrophysics Data System (ADS)

    Pei, Xin; Pan, Yan; Wang, Haixin; Wong, S. C.; Choi, Keechoo

    2016-05-01

    Car-following models, which describe the reactions of the driver of a following car to the changes of the leading car, are essential for the development of traffic flow theory. A car-following model with a stochastic memory effect is considered to be more realistic in modeling drivers' behavior. Because a gamma-distributed memory function has been shown to outperform other forms according to empirical data, in this study, we thus focus on a car-following model with a gamma-distributed memory effect; analytical and numerical studies are then conducted for stability analysis. Accordingly, the general expression of undamped and stability points is achieved by analytical study. The numerical results show great agreement with the analytical results: introducing the effect of the driver's memory causes the stable regions to weaken slightly, but the metastable region is obviously enlarged. In addition, a numerical study is performed to further analyze the variation of the stable and unstable regions with respect to the different profiles of gamma distribution.

  20. Measurement and Analysis of Gamma-Rays Emitted From Spent Nuclear Fuel Above 3 MeV

    SciTech Connect

    Rodriguez, Douglas C.; Anderson, Elaina R.; Anderson, Kevin K.; Campbell, Luke W.; Fast, James E.; Jarman, Kenneth D.; Kulisek, Jonathan A.; Orton, Christopher R.; Runkle, Robert C.; Stave, Sean C.

    2013-12-01

    The gamma-ray spectrum of spent nuclear fuel in the 3- to 6-MeV energy range is important for active interrogation since emitted gamma rays emitted from nuclear decay are not expected to interfere with measurements in this energy region. There is, unfortunately, a dearth of empirical measurements from spent nuclear fuel in this region. This work is an initial attempt to partially ll this gap by presenting an analysis of gamma-ray spectra collected from a set of spent nuclear fuel sources using a high-purity germanium detector array. This multi-crystal array possesses a large collection volume, providing high energy resolution up to 16 MeV. The results of these measurements establish the continuum count-rate in the energy region between 3- and 6-MeV. Also assessed is the potential for peaks from passive emissions to interfere with peak measurements resulting from active interrogation delayed emissions. As one of the first documented empirical measurements of passive emissions from spent fuel for energies above 3 MeV, this work provides a foundation for active interrogation model validation and detector development.

  1. Measurement and analysis of gamma-rays emitted from spent nuclear fuel above 3 MeV.

    PubMed

    Rodriguez, Douglas C; Anderson, Elaina; Anderson, Kevin K; Campbell, Luke W; Fast, James E; Jarman, Kenneth; Kulisek, Jonathan; Orton, Christopher R; Runkle, Robert C; Stave, Sean

    2013-12-01

    The gamma-ray spectrum of spent nuclear fuel in the 3-6 MeV energy range is important for active interrogation since gamma rays emitted from nuclear decay are not expected to interfere with measurements in this energy region. There is, unfortunately, a dearth of empirical measurements from spent nuclear fuel in this region. This work is an initial attempt to partially fill this gap by presenting an analysis of gamma-ray spectra collected from a set of spent nuclear fuel sources using a high-purity germanium detector array. This multi-crystal array possesses a large collection volume, providing high energy resolution up to 16 MeV. The results of these measurements establish the continuum count-rate in the energy region between 3 and 6 MeV. Also assessed is the potential for peaks from passive emissions to interfere with peak measurements resulting from active interrogation delayed emissions. As one of the first documented empirical measurements of passive emissions from spent fuel for energies above 3 MeV, this work provides a foundation for active interrogation model validation and detector development. PMID:24035928

  2. GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

    SciTech Connect

    Turick, C.; Ekechukwu, A.; Milliken, C.

    2011-05-17

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

  3. Gamma radiation interacts with melanin to alter its oxidation-reduction potential and results in electric current production.

    PubMed

    Turick, Charles E; Ekechukwu, Amy A; Milliken, Charles E; Casadevall, Arturo; Dadachova, Ekaterina

    2011-08-01

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials. PMID:21632287

  4. Cloning, Expression and Biological Analysis of Recombinant Chicken IFN-gamma Expressed in Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The interferon-gamma (CHIFN-') derived from the spleen cells of White Leghorns chicken, a local Chinese breeding species was amplified by RT-PCR. The gene encoding CHIFN-' with the deletion of the N-terminal signal peptide was cloned into prokaryotic expression vector pET30a, resulting in a recombin...

  5. Improved neutron-gamma discrimination for a 6Li-glass neutron detector using digital signal analysis methods

    DOE PAGESBeta

    Wang, Cai -Lin; Riedel, Richard A.

    2016-01-14

    A 6Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at SNS. Traditional pulse-height analysis (PHA) for neutron-gamma discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 104. The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, five digital signal analysis methods of individual waveforms from PMTs were proposed using: i). pulse-amplitude histogram; ii). power spectrum analysis combined with the maximum pulse amplitude; iii). two event parameters (a1, b0) obtained from Wiener filter; iv). an effective amplitude (m)more » obtained from an adaptive least-mean-square (LMS) filter; and v). a cross-correlation (CC) coefficient between an individual waveform and a reference. The NGD ratios can be 1-102 times those from traditional PHA method. A brighter scintillator GS2 has better NGD ratio than GS20, but lower neutron detection efficiency. The ultimate NGD ratio is related to the ambient, high-energy background events. Moreover, our results indicate the NGD capability of neutron Anger cameras can be improved using digital signal analysis methods and brighter neutron scintillators.« less

  6. Improved neutron-gamma discrimination for a 6Li-glass neutron detector using digital signal analysis methods

    NASA Astrophysics Data System (ADS)

    Wang, C. L.; Riedel, R. A.

    2016-01-01

    A 6Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at Spallation Neutron Source. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 104. The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, six digital signal analysis methods of individual waveforms acquired from photomultiplier tubes were proposed using (i) charge integration, (ii) pulse-amplitude histograms, (iii) power spectrum analysis combined with the maximum pulse-amplitude, (iv) two event parameters (a1, b0) obtained from a Wiener filter, (v) an effective amplitude (m) obtained from an adaptive least-mean-square filter, and (vi) a cross-correlation coefficient between individual and reference waveforms. The NGD ratios are about 70 times those from the traditional PHA method. Our results indicate the NGD capabilities of neutron Anger cameras based on GS20 scintillators can be significantly improved with digital signal analysis methods.

  7. Improved neutron-gamma discrimination for a (6)Li-glass neutron detector using digital signal analysis methods.

    PubMed

    Wang, C L; Riedel, R A

    2016-01-01

    A (6)Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at Spallation Neutron Source. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 10(4). The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, six digital signal analysis methods of individual waveforms acquired from photomultiplier tubes were proposed using (i) charge integration, (ii) pulse-amplitude histograms, (iii) power spectrum analysis combined with the maximum pulse-amplitude, (iv) two event parameters (a1, b0) obtained from a Wiener filter, (v) an effective amplitude (m) obtained from an adaptive least-mean-square filter, and (vi) a cross-correlation coefficient between individual and reference waveforms. The NGD ratios are about 70 times those from the traditional PHA method. Our results indicate the NGD capabilities of neutron Anger cameras based on GS20 scintillators can be significantly improved with digital signal analysis methods. PMID:26827314

  8. Furan formation from fatty acids as a result of storage, gamma irradiation, UV-C and heat treatments.

    PubMed

    Fan, Xuetong

    2015-05-15

    The effects of gamma and UV-C irradiation in comparison with thermal processing and storage at 25°C on formation of furan from different fatty acids were investigated. Results showed that furan was generated from polyunsaturated fatty acids such as linoleic and linolenic acid during thermal (120°C, 25 min) and UV-C (11.5 J/cm(2)) treatments. Gamma irradiation (up to 20 kGy) did not induce formation of significant amounts of furan from any of the fatty acids studied. Storage of unsaturated fatty acid emulsions at 25°C for 3 days led to the formation of furan (7-11 ng/mL) even without prior thermal or non-thermal treatments. pH significantly impacted furan formation with >3.5 times more furan formed at pH 9 than at pHs 3 or 6 during 3 days at 25°C. The addition of Trolox, BHA, and propyl gallate had no significant effect on furan formation from linolenic acid while α-tocopherol and FeSO4 promoted furan formation. PMID:25577103

  9. Photon Activation Analysis Of Light Elements Using 'Non-Gamma' Radiation Spectroscopy - The Instrumental Determination Of Phosphorus

    SciTech Connect

    Segebade, Christian; Goerner, Wolf

    2011-06-01

    Unlike metal determinations the analysis of light elements (e.g., carbon, oxygen, phosphorus) is frequently problematic, in particular if analysed instrumentally. In photon activation analysis (PAA) the respective activation products do not emit gamma radiation in the most cases. Usually, annihilation quanta counting and subsequent decay curve analysis have been used for determinations of C, N, O, and F. However, radiochemical separation of the respective radioisotopes mostly is indispensable. For several reasons, some of the light elements cannot be analysed following this procedure, e.g. phosphorus. In this contribution the instrumental PAA of phosphorus in organic matrix by activation with bremsstrahlung of an electron linear accelerator and subsequent beta spectroscopy is described. The accuracy of the results was excellent as obtained by analysis of a BCR Reference Material.

  10. Lunar elemental analysis obtained from the Apollo gamma-ray and X-ray remote sensing experiment

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Arnold, J. R.; Adler, I.; Metzger, A. E.; Reedy, R. C.

    1977-01-01

    Gamma-ray and X-ray spectrometers carried in the service modules of the Apollo 15 and Apollo 16 spacecraft were employed for compositional mapping of the lunar surface. The measurements involved the observation of the intensity and characteristic energy distribution of gamma rays and X-rays emitted from the lunar surface. A large-scale compositional map of over 10 percent of the lunar surface was obtained from an analysis of the observed spectra. The objective of the X-ray experiment was to measure the K spectral lines from Mg, Al, and Si. Spectra were obtained and the data were reduced to Al/Si and Mg/Si intensity ratios and ultimately to chemical ratios. Analyses of the results have indicated (1) that the Al/Si ratios are highest in the lunar highlands and considerably lower in the maria, and (2) that the Mg/Si concentrations generally show the opposite relationship. The objective of the gamma-ray experiment was to measure the natural and cosmic-ray-induced activity emission spectrum. At this time, the elemental abundances for Th, U, K, Fe, Ti, Si, and O have been determined over a number of major lunar regions. Regions of relatively high natural radioactivity were found in the Mare Imbrium and Oceanus Procellarum regions.

  11. EBAC-DCC Analysis of World Data of pi N, gamma N, and N(e,e') Reactions

    SciTech Connect

    Hiroyuki Kamano,Tsung-Shung Lee

    2012-04-01

    The development, results, and prospect of the Dynamical Coupled-Channels analysis at Excited Baryon Analysis Center (EBAC-DCC) are reported. In this contribution, we report on the development, results, and prospect of EBAC. The EBAC project has three components, as illustrated in Fig. 1. The first task is to perform a dynamical coupled-channels analysis of the world data of {pi}N, {gamma}*N {yields} {pi}N, {eta}N, {pi}{pi}N, K{Lambda}, K{Sigma}, {omega}N, {hor_ellipsis} to determine the meson-baryon partial-wave amplitudes. The second step is to develop a procedure to extract the N* parameters from the determined partial-wave amplitudes. The third step is to investigate the interpretations of the extracted N* properties in terms of the available hadron models and Lattice QCD.

  12. Overexpression of the 14-3-3gamma protein in embryonic mice results in neuronal migration delay in the developing cerebral cortex.

    PubMed

    Cornell, Brett; Wachi, Tomoka; Zhukarev, Vladimir; Toyo-Oka, Kazuhito

    2016-08-15

    The 14-3-3 protein family is a group of multifunctional proteins that are highly expressed in the brain; however, their functions in brain development are largely unknown. Williams Syndrome is a neurodevelopmental disorder caused by a deletion in the 7q11.23 chromosome locus, including the gene encoding 14-3-3gamma, resulting in developmental delay, intellectual disabilities and epilepsy. We have previously shown that knocking down the 14-3-3gamma protein in utero in mice results in delays in neuronal migration of pyramidal neurons in the cortex. Importantly, there is a reciprocal duplication syndrome to Williams Syndrome where the 7q11.23 locus is duplicated, resulting in epilepsy and intellectual disabilities. Thus, the deletion or the duplication of the 7q11.23 chromosome locus results in epilepsy. Taken together with the fact that defects in neuronal migration are one of main causes for epilepsy, we analyzed if the overexpression of 14-3-3gamma causes neuronal migration defects. In this work, we found that the overexpression of 14-3-3gamma in utero in the developing mouse cortex results in delays in pyramidal neuron migration, similar to what was previously observed when 14-3-3gamma was knocked down. These results, in conjunction with our previous research, indicate that a balance of 14-3-3gamma expression is required during cortical development to prevent delays in neuronal migration. This work provides clear evidence as to the involvement of 14-3-3gamma in neurodevelopmental disorders and how a disruption in 14-3-3gamma expression may contribute to the neurodevelopmental disorders that manifest when the 7q11.23 locus is altered. PMID:27288018

  13. Analysis of positional isotope exchange in ATP by cleavage of the. beta. P-O. gamma. P bond. Demonstration of negligible positional isotope exchange by myosin

    SciTech Connect

    Dale, M.P.; Hackney, D.D.

    1987-12-15

    A method for analysis of positional isotope exchange (PIX) during ATP in equilibrium HOH oxygen exchange is presented that uses a two-step degradation of ATP resulting in cleavage of the ..beta..P-O..gamma..P bond. This cleavage yields P/sub i/ derived from the ..gamma..-phosphoryl of ATP that contains all four of the ..gamma.. oxygens. Both PIX between the ..beta.., ..gamma..-bridge and ..beta..-nonbridge positions and washout of the ..gamma..-nonbridge oxygens can be simultaneously followed by using ATP labeled with /sup 17/O at the ..beta..-nonbridge positions and /sup 18/O at the ..beta..,..gamma..-bridge and ..gamma..-nonbridge positions. Application of this method to ATP in equilibrium HOH exchange during single turnovers of myosin indicates that the bulk of the ATP undergoes rapid washout of ..gamma..-nonbridge oxygens in the virtual absence of PIX. At 25/sup 0/C with subfragment 1 the scrambling rate is at the limit of detectability of approximately 0.001 s/sup -1/, which is 50-fold slower than the steady-state rate. This corresponds to a probability of scrambling for the ..beta..-oxygens of bound ADP of 1 in 10,000 for each cycle of reversible hydrolysis of bound ATP. A fraction of the ATP, however, does not undergo rapid washout. With myosin and stoichiometric ATP at 0/sup 0/C, this fraction correspond to 10% of the ATP remaining at 36 s, or 2% of the initial ATP, and an equivalent level of ATP is found that does not bind irreversibly to myosin in a cold chase experiment. A significant level of apparent PIX is observed with subfragment 1 in the fraction that resists washout, and this apparent PIX is shown to be due to contaminant adenylate kinase activity. This apparent PIX due to adenylate kinase provides a possible explanation for the PIX observed by Geeves et al. with subfragment 1.

  14. Gamma radiological surveys of the Oak Ridge Reservation, Paducah Gaseous Diffusion Plant, and Portsmouth Gaseous Diffusion Plant, 1990-1993, and overview of data processing and analysis by the Environmental Restoration Remote Sensing Program, Fiscal Year 1995

    SciTech Connect

    Smyre, J.L.; Moll, B.W.; King, A.L.

    1996-06-01

    Three gamma radiological surveys have been conducted under auspices of the ER Remote Sensing Program: (1) Oak Ridge Reservation (ORR) (1992), (2) Clinch River (1992), and (3) Portsmouth Gaseous Diffusion Plant (PORTS) (1993). In addition, the Remote Sensing Program has acquired the results of earlier surveys at Paducah Gaseous Diffusion Plant (PGDP) (1990) and PORTS (1990). These radiological surveys provide data for characterization and long-term monitoring of U.S. Department of Energy (DOE) contamination areas since many of the radioactive materials processed or handled on the ORR, PGDP, and PORTS are direct gamma radiation emitters or have gamma emitting daughter radionuclides. High resolution airborne gamma radiation surveys require a helicopter outfitted with one or two detector pods, a computer-based data acquisition system, and an accurate navigational positioning system for relating collected data to ground location. Sensors measure the ground-level gamma energy spectrum in the 38 to 3,026 KeV range. Analysis can provide gamma emission strength in counts per second for either gross or total man-made gamma emissions. Gross count gamma radiation includes natural background radiation from terrestrial sources (radionuclides present in small amounts in the earth`s soil and bedrock), from radon gas, and from cosmic rays from outer space as well as radiation from man-made radionuclides. Man-made count gamma data include only the portion of the gross count that can be directly attributed to gamma rays from man-made radionuclides. Interpretation of the gamma energy spectra can make possible the determination of which specific radioisotopes contribute to the observed man-made gamma radiation, either as direct or as indirect (i.e., daughter) gamma energy from specific radionuclides (e.g., cesium-137, cobalt-60, uranium-238).

  15. Preliminary results of oxygen isotope ratio measurement with a particle-gamma coincidence method

    NASA Astrophysics Data System (ADS)

    Borysiuk, Maciek; Kristiansson, Per; Ros, Linus; Abdel, Nassem S.; Elfman, Mikael; Nilsson, Charlotta; Pallon, Jan

    2015-04-01

    The possibility to study variations in the oxygen isotopic ratio with photon tagged nuclear reaction analysis (pNRA) is evaluated in the current work. The experiment described in the article was performed at Lund Ion Beam Analysis Facility (LIBAF) with a 2 MeV deuteron beam. Isotopic fractionation of light elements such as carbon, oxygen and nitrogen is the basis of many analytical tools in hydrology, geology, paleobiology and paleogeology. IBA methods provide one possible tool for measurement of isotopic content. During this experimental run we focused on measurement of the oxygen isotopic ratio. The measurement of stable isotopes of oxygen has a number of applications; the particular one driving the current investigation belongs to the field of astrogeology and specifically evaluation of fossil extraterrestrial material. There are three stable isotopes of oxygen: 16O, 17O and 18O. We procured samples highly enriched with all three isotopes. Isotopes 16O and 18O were easily detected in the enriched samples, but no significant signal from 17O was detected in the same samples. The measured yield was too low to detect 18O in a sample with natural abundances of oxygen isotopes, at least in the current experimental setup, but the spectral line from the reaction with 16O was clearly visible.

  16. N-SAP and G-SAP neutron and gamma ray albedo model scatter shield analysis program

    NASA Technical Reports Server (NTRS)

    Sapovchak, B. J.; Stephenson, L. D.

    1967-01-01

    Computer program calculates neutron or gamma ray first order scattering from a plane or cylindrical surface to a detector point. The SAP Codes, G-SAP and N-SAP, constitute a multiple scatter albedo model shield analysis.

  17. Two-loop effective theory analysis of pi (K)-->enu[over ]_{e}[gamma] branching ratios.

    PubMed

    Cirigliano, Vincenzo; Rosell, Ignasi

    2007-12-01

    We study the ratios R_{e/mu};{(P)} identical withGamma(P-->enu[over ]_{e}[gamma])/Gamma(P-->munu[over ]_{mu}[gamma]) (P=pi, K) in Chiral Perturbation Theory to order e;{2}p;{4}. We complement the two-loop effective theory results with a matching calculation of the counterterm, finding R_{e/mu};{(pi)}=(1.2352+/-0.0001)x10;{-4} and R_{e/mu};{(K)}=(2.477+/-0.001)x10;{-5}. PMID:18233356

  18. Gamma-ray bursts associated with supernovae: a systematic analysis of BATSE GRB candidates

    NASA Astrophysics Data System (ADS)

    Bosnjak, Z.; Celotti, A.; Ghirlanda, G.; Della Valle, M.; Pian, E.

    2006-02-01

    We examined the properties of a sample of BATSE Gamma-Ray Bursts (GRBs) comprising events which have indications of association with a supernova (SN), some on the basis of indications of re-brightening in the optical afterglow light curve, but in most cases based only on the "loose" temporal and directional coincidence inferred from the cross correlation of catalogs. Despite the large uncertainties in the latter selection method, the temporal and spectral analysis reveal three interesting statistical results when the sample is compared with that of all the BATSE GRBs: the GRBs tentatively associated with SNe are found to predominantly (in ~80% of the cases) have single-peaked light curves, a softer spectrum (i.e. low energy power law index α ˜ -1.5) and tend not to follow the Lag-Luminosity and Isotropic Energy-Peak Energy correlations. These three independent statistical properties point toward the existence of a significant number of under-luminous, GRB 980425-like events constituting - at least from an observational point of view - a tail or a separate class with respect to the whole of the BATSE GRB events. The unusually high percentage of SN Ibc among those identified by the catalog cross-correlation (a factor ~four higher than expected from SN catalog statistics) reinforces the non-randomness of some of the selected events.

  19. New method for estimation of fluence complexity in IMRT fields and correlation with gamma analysis

    NASA Astrophysics Data System (ADS)

    Hanušová, T.; Vondráček, V.; Badraoui-Čuprová, K.; Horáková, I.; Koniarová, I.

    2015-01-01

    A new method for estimation of fluence complexity in Intensity Modulated Radiation Therapy (IMRT) fields is proposed. Unlike other previously published works, it is based on portal images calculated by the Portal Dose Calculation algorithm in Eclipse (version 8.6, Varian Medical Systems) in the plane of the EPID aS500 detector (Varian Medical Systems). Fluence complexity is given by the number and the amplitudes of dose gradients in these matrices. Our method is validated using a set of clinical plans where fluence has been smoothed manually so that each plan has a different level of complexity. Fluence complexity calculated with our tool is in accordance with the different levels of smoothing as well as results of gamma analysis, when calculated and measured dose matrices are compared. Thus, it is possible to estimate plan complexity before carrying out the measurement. If appropriate thresholds are determined which would distinguish between acceptably and overly modulated plans, this might save time in the re-planning and re-measuring process.

  20. Analysis of VLF signals associated to AGILE Terrestrial Gamma-ray Flashes detected over Central America

    NASA Astrophysics Data System (ADS)

    Marisaldi, Martino; Lyu, Fanchao; Cummer, Steven; Ursi, Alessandro

    2016-04-01

    Analysis of radio signals detected on ground and associated to Terrestrial Gamma-ray Flashes (TGFs) have proven to be a successful tool to extract information on the TGF itself and the possible associated lightning process. Triangulation of Very Low Frequency (VLF) signals by means of the Time Of Arrival technique provides TGF location with few km accuracy. The AGILE satellite is routinely observing TGFs on a narrow band across the Equator, limited by the small satellite orbital inclination (2.5°). However, until recently it was not possible to provide firm associations between AGILE TGFs and radio signals, because of two main limiting factors. First, dead-time effects led to a bias towards long duration events in AGILE TGF sample, which are less likely associated to strong radio pulses. In addition, most VLF detection networks are less sensitive along the equatorial region. Since the end of March 2015 a major change in the AGILE MiniCalorimeter instrument configuration resulted in a ten fold increase in TGF detection rate, and in the detection of events as short as 20 microseconds. 14% of the events in the new sample resulted simultaneous (within 200 microseconds) to sferics detected by the World Wide Lightning Location Network (WWLLN), therefore a source localisation is available for these events. We present here the first analysis of VLF waveforms associated to AGILE TGFs observed above Central America, detected by magnetic field sensors deployed in Puerto Rico. Among the seven TGFs with a WWLLN location at a distance lower than 10000 km from the sensors, four of them have detectable signals. These events are the closest to the sensors, with distance less than 7500 km. We present here the properties of these TGFs and the characteristics of the associated radio waveforms.

  1. Summary of CPAS EDU Testing Analysis Results

    NASA Technical Reports Server (NTRS)

    Romero, Leah M.; Bledsoe, Kristin J.; Davidson, John.; Engert, Meagan E.; Fraire, Usbaldo, Jr.; Galaviz, Fernando S.; Galvin, Patrick J.; Ray, Eric S.; Varela, Jose

    2015-01-01

    The Orion program's Capsule Parachute Assembly System (CPAS) project is currently conducting its third generation of testing, the Engineering Development Unit (EDU) series. This series utilizes two test articles, a dart-shaped Parachute Compartment Drop Test Vehicle (PCDTV) and capsule-shaped Parachute Test Vehicle (PTV), both of which include a full size, flight-like parachute system and require a pallet delivery system for aircraft extraction. To date, 15 tests have been completed, including six with PCDTVs and nine with PTVs. Two of the PTV tests included the Forward Bay Cover (FBC) provided by Lockheed Martin. Advancements in modeling techniques applicable to parachute fly-out, vehicle rate of descent, torque, and load train, also occurred during the EDU testing series. An upgrade from a composite to an independent parachute simulation allowed parachute modeling at a higher level of fidelity than during previous generations. The complexity of separating the test vehicles from their pallet delivery systems necessitated the use the Automatic Dynamic Analysis of Mechanical Systems (ADAMS) simulator for modeling mated vehicle aircraft extraction and separation. This paper gives an overview of each EDU test and summarizes the development of CPAS analysis tools and techniques during EDU testing.

  2. Determination of boron in materials by cold neutron prompt gamma-ray activation analysis.

    PubMed

    Paul, Rick L

    2005-01-01

    An instrument for cold neutron prompt gamma-ray activation analysis (PGAA), located at the NIST Center for Neutron Research (NCNR), has proven useful for the measurement of boron in a variety of materials. Neutrons, moderated by passage through liquid hydrogen at 20 K, pass through a (58)Ni coated guide to the PGAA station in the cold neutron guide hall of the NCNR. The thermal equivalent neutron fluence rate at the sample position is 9 x 10(8) cm(-2) s(-1). Prompt gamma rays are measured by a cadmium- and lead-shielded high-purity germanium detector. The instrument has been used to measure boron mass fractions in minerals, in NIST SRM 2175 (Refractory Alloy MP-35-N) for certification of boron, and most recently in semiconductor-grade silicon. The limit of detection for boron in many materials is <10 ng g(-1). PMID:15614360

  3. Gamma-Ray Spectrometer based on a Transition Edge Sensor for Nuclear Materials Analysis

    NASA Astrophysics Data System (ADS)

    Hatakeyama, S.; Ohno, M.; Takahashi, H.; Damayanthi, R. M. T.; Otani, C.; Yasumune, T.; Ohnishi, T.; Takasaki, K.; Koyama, S.

    2014-08-01

    We designed and fabricated a hard X-ray and gamma-ray TES spectrometer for nuclear materials analysis. The superconducting tin absorber is coupled to an Ir/Au TES by using a gold post to improve the thermal contact between the absorber and the TES. The reported energy resolution is 156 eV FWHM at 59.5 keV and 166 eV FWHM at 122 keV gamma-rays. We performed measurement of a Pu sample and clearly separated the Pu (56.828 keV) and the Am (59.5 keV) peaks by this TES microcalorimeter which cannot be resolved by the HPGe detector.

  4. Design of a program in Matlab environment for gamma spectrum analysis of geological samples

    NASA Astrophysics Data System (ADS)

    Rojas, M.; Correa, R.

    2016-05-01

    In this work we present the analysis of gamma ray spectra Ammonites found in different places. One of the fossils was found near the city of Cusco (Perú) and the other in “Cajón del Maipo” in Santiago (Chile). Spectra were taken with a hyperpure germanium detector (HPGe) in an environment cooled with liquid nitrogen, with the technique of high-resolution gamma spectroscopy. A program for automatic detection and classifying of the samples was developed in Matlab. It program has the advantage of being able to make direct interventions or generalize it even more, or make it automate for specific spectra and make comparison between them. For example it can calibrate the spectrum automatically, only by giving the calibration spectrum, without the necessity of putting them. Finally, it also erases the external noise.

  5. Event-sequence time series analysis in ground-based gamma-ray astronomy

    SciTech Connect

    Barres de Almeida, U.; Chadwick, P.; Daniel, M.; Nolan, S.; McComb, L.

    2008-12-24

    The recent, extreme episodes of variability detected from Blazars by the leading atmospheric Cerenkov experiments motivate the development and application of specialized statistical techniques that enable the study of this rich data set to its furthest extent. The identification of the shortest variability timescales supported by the data and the actual variability structure observed in the light curves of these sources are some of the fundamental aspects being studied, that answers can bring new developments on the understanding of the physics of these objects and on the mechanisms of production of VHE gamma-rays in the Universe. Some of our efforts in studying the time variability of VHE sources involve the application of dynamic programming algorithms to the problem of detecting change-points in a Poisson sequence. In this particular paper we concentrate on the more primary issue of the applicability of counting statistics to the analysis of time-series on VHE gamma-ray astronomy.

  6. Principal Component Analysis of Long-Lag,Wide-Pulse Gamma-Ray Burst Data

    NASA Astrophysics Data System (ADS)

    Peng, Zhao-Yang; Liu, Wen-Shuai

    2014-09-01

    We have carried out a Principal Component Analysis (PCA) of the temporal and spectral variables of 24 long-lag, wide-pulse gamma-ray bursts (GRBs) presented by Norris et al. (2005). Taking all eight temporal and spectral parameters into account, our analysis shows that four principal components are enough to describe the variation of the temporal and spectral data of long-lag bursts. In addition, the first-two principal components are dominated by the temporal variables while the third and fourth principal components are dominated by the spectral parameters.

  7. Continuous versus pulse neutron induced gamma spectroscopy for soil carbon analysis.

    PubMed

    Kavetskiy, A; Yakubova, G; Torbert, H A; Prior, S A

    2015-02-01

    Neutron induced gamma spectra analysis (NGA) provides a means of measuring carbon in large soil volumes without destructive sampling. Calibration of the NGA system must account for system background and the interference of other nuclei on the carbon peak at 4.43 MeV. Accounting for these factors produced measurements in agreement with theoretical considerations. The continuous NGA mode was twice as fast and just as accurate as the pulse mode, thus this mode was preferable for routine soil carbon analysis. PMID:25497322

  8. Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

    SciTech Connect

    Firestone, Richard B; English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Leung, Ka-Ngo; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

    2008-02-13

    Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents.1-3. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity.

  9. Application of PERALS™ alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects.

    PubMed

    Borysenko, A; Ostrowski, A; Bellifemine, D; Palmer, G; Haigh, P; Johnston, A

    2014-03-01

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project-prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS™ alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g(-1) by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring. PMID:24270399

  10. Biochemical analysis of proteasomes from mouse microglia: induction of immunoproteasomes by interferon-gamma and lipopolysaccharide.

    PubMed

    Stohwasser, R; Giesebrecht, J; Kraft, R; Müller, E C; Häusler, K G; Kettenmann, H; Hanisch, U K; Kloetzel, P M

    2000-02-15

    The 20S proteasome is a multicatalytic threonine protease and serves to process peptides that are subsequently presented as antigenic epitopes by MHC class I molecules. In the brain, microglial cells are the major antigen presenting cells and they respond sensitive to pathologic events. We used cultured mouse microglia and a microglial cell line, the BV-2 line, as a model to study the correlation between microglial activation parameters and structural plasticity of the 20S/26S proteasome. Lipopolysaccharide (LPS)- or interferon-gamma (IFN-gamma)-stimulated microglia or BV-2 cells exhibit properties of activated microglia such as high levels of TNFalpha and IL-6 release. In response to IFN-gamma or LPS, three constitutive beta subunits (beta1/Delta, beta2/MC14, beta5/MB1) were replaced by the immunoproteasome subunits ibeta1/LMP2, ibeta2/MECL-1, and ibeta5/LMP7, indicating that activated microglia adapts its proteasomal subunit composition to the requirements of an optimized MHC class I epitope processing. Induction of immunoproteasomes in BV-2 cells was solely provoked by IFN-gamma, but not by LPS. Moreover, LPS (but not IFN-gamma) triggered the expression of a novel protein of approximately 50 kD as part of the proteasome activator PA700, that is the substrate-recognizing and unfolding unit of the 26S proteasome. These results indicate that both the 20S core protease as well as the proteasome activator PA700 are targets of modulatory subunit replacements or transient association of regulatory components in the course of microglial activation. PMID:10652445

  11. Intracranial aneurysms: analysis of results of microneurosurgery.

    PubMed Central

    Adams, C B; Loach, A B; O'laoire, S A

    1976-01-01

    Subarachnoid haemorrhage from intracranial aneurysms has a poor prognosis. Operative management of intracranial aneurysms was once considered ineffective. The first 100 cases treated by micorsurgery were analysed to see whether mortality and morbidity were reduced. Modern surgical techniques halved the total mortality but the morbidity was unaltered. Results can be improved by delaying surgery seven days and by treating any hypertension before surgery. PMID:963461

  12. Closed form analysis of a gamma, back-to-back free displacer Stirling engine

    SciTech Connect

    Lewis, K.L.; Kilgour, D.B.; Lazarides, Y.G.; Rallis, C.J.

    1983-08-01

    A back-to-back, free displacer, gamma type Stirling engine has been designed and is currently under manufacture and development at the University of the Witwatersrand. This paper presents a simple idealized analysis for such an engine. It involves the coupling together of the thermodynamic and mechanical equations, and by the use of classical control and vibration theory, closed form solutions are obtained. This work follows up on previous methods of analysis developed by Berchowitz, WyattMair and Goldberg for similar types of engines. A numerical application of the analysis has been carried out for the design in order to evaluate the operating frequency, phase displacements, amplitude of oscillation and basic output power. Performance characteristics are obtained and detailed in the paper. The analysis has provided analytic proof of the viability of the proposed engine configuration, highlighted weak areas and provided a background to higher order analysis. A programme of experimental validation is under way.

  13. Gamma Knife Radiosurgery for Patients With Nonfunctioning Pituitary Adenomas: Results From a 15-Year Experience

    SciTech Connect

    Pollock, Bruce E. Cochran, Joseph; Natt, Neena; Brown, Paul D.; Erickson, Dana; Link, Michael J.; Garces, Yolanda I.; Foote, Robert L.; Stafford, Scott L.; Schomberg, Paula J.

    2008-04-01

    Purpose: To evaluate the efficacy and complications of stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas (NFA). Methods and Materials: This was a retrospective review of 62 patients with NFA undergoing radiosurgery between 1992 and 2004, of whom 59 (95%) underwent prior tumor resection. The median treatment volume was 4.0 cm{sup 3} (range, 0.8-12.9). The median treatment dose to the tumor margin was 16 Gy (range, 11-20). The median maximum point dose to the optic apparatus was 9.5 Gy (range, 5.0-12.6). The median follow-up period after radiosurgery was 64 months (range, 23-161). Results: Tumor size decreased for 37 patients (60%) and remained unchanged for 23 patients (37%). Two patients (3%) had tumor growth outside the prescribed treatment volume and required additional treatment (fractionated radiation therapy, n = 1; repeat radiosurgery, n 1). Tumor growth control was 95% at 3 and 7 years after radiosurgery. Eleven (27%) of 41 patients with normal (n = 30) or partial (n = 11) anterior pituitary function before radiosurgery developed new deficits at a median of 24 months after radiosurgery. The risk of developing new anterior pituitary deficits at 5 years was 32%. The 5-year risk of developing new anterior pituitary deficits was 18% for patients with a tumor volume of {<=}4.0 cm{sup 3} compared with 58% for patients with a tumor volume >4.0 cm{sup 3} (risk ratio 4.5; 95% confidence interval = 1.3-14.9, p = 0.02). No patient had a decline in visual function. Conclusions: Stereotactic radiosurgery is effective in the management of patients with residual or recurrent NFA, although longer follow-up is needed to evaluate long-term outcomes. The primary complication is hypopituitarism, and the risk of developing new anterior pituitary deficits correlates with the size of the irradiated tumor.

  14. Evaluation of an in vivo prompt gamma neutron activation facility for body composition studies in critically ill intensive care patients: results on 41 normals

    SciTech Connect

    Beddoe, A.H.; Streat, S.J.; Hill, G.L.

    1984-03-01

    A programme of metabolic and nutritional research is being undertaken in critically ill patients requiring intensive care. Central to this research is the measurement of the three nutritionally important compartments of body composition, protein, fat, and water by a combination of tritium dilution and prompt gamma in vivo neutron activation analysis (IVNAA). In this paper a calibration technique is presented that enables absolute estimates of total body nitrogen (TBN) to be made using prompt gamma IVNAA in critically ill patients with gross abnormalities in body composition, especially in their state of hydration. This technique, which is independent of skinfold anthropometry and does not make a priori assumptions about the ratios of major body compartments, has been applied to 41 normal volunteers and the derived values for nitrogen compared with values obtained by applying three currently used calibration methods to the same experimental data. The empirical equations relate TBN in normal people to age, height, weight and sex. The mean ratios of experimental to predicted TBN (with SEMs) are 1.013 +/- 0.017 and 1.002 +/- 0.014, respectively. Mean values of the ratio of TBN to fat-free mass (0.0340 +/- 0.0004) and of total body water to fat-free mass (0.716 +/- 0.002) agree closely with values reported elsewhere for normals by a variety of techniques including chemical analysis. Finally, TBN results based on the four different calibration methods are presented for five surgical patients, demonstrating the importance of the calibration method on estimates of TBN in patients with abnormal body composition. It is concluded that this technique will provide accurate estimates of the total body content of protein, water, and fat in intensive care patients.

  15. Correlation analysis of 1 to 30 MeV celestial gamma rays

    SciTech Connect

    Long, J.L.

    1984-01-01

    This paper outlines the development of a method of producing celestial sky maps from the data generated by the University of California, Riverside's double Compton scatter gamma ray telescope. The method makes use of a correlation between the telescope's data and theoretical calculated response functions. The results of applying this technique to northern hemisphere data obtained from a 1978 balloon flight from Palestine, Texas are included.

  16. The analysis of failed nuclear fuel rods by gamma computed tomography

    NASA Astrophysics Data System (ADS)

    Dobrin, Relu; Craciunescu, Teddy; Tuturici, Ioan Liviu

    1997-07-01

    The failure of the cladding of an irradiated nuclear fuel rod can lead to the loss of some γ-radioactive fission products. Consequently the distribution of these fission products is altered in the cross-section of the fuel rod. The modification of the distribution, obtained by gamma computed tomography, is used to determine the integrity of the fuel cladding. The paper reports an experimental result, obtained for a CANDU-type fuel rod, irradiated in a TRIGA 14 MWth reactor.

  17. Analysis of Line Candidates in Gamma-Ray Bursts Observed by BATSE

    NASA Technical Reports Server (NTRS)

    Briggs, M. S.; Band, D. L.; Preece, R. D.; Paciesas, W. S.; Pendleton, G. N.

    1999-01-01

    A comprehensive search of BATSE Spectroscopy Detector data from 117 Gamma Ray Bursts (GRBs) has uncovered 13 statistically significant line candidates. The case of a candidate in GRB-930916 is discussed. In the data of SD-2 there appears to be a emission line at 46 keV, however the line is not seen in the data of SD-7. Simulations indicate that the lack of agreement between the results from SD-2 and SD-7 is implausible but not impossible.

  18. SU-E-T-77: Comparison of 2D and 3D Gamma Analysis in Patient-Specific QA for Prostate VMAT Plans

    SciTech Connect

    Clemente, F; Perez, C

    2014-06-01

    Purpose: Patient-specific QA procedures for IMRT and VMAT are traditionally performed by comparing TPS calculations with measured single point values and plane dose distributions by means of gamma analysis. New QA devices permit us to calculate 3D dose distributions on patient anatomy as redundant secondary check and reconstruct it from measurements taken with 2D and 3D detector arrays. 3D dose calculations allow us to perform DVH-based comparisons with clinical relevance, as well as 3D gamma analysis. One of these systems (Compass, IBA Dosimetry) combines traditional 2D with new anatomical-based 3D gamma analysis. This work shows the ability of this system by comparing 2D and 3D gamma analysis in pre-treatment QA for several VMAT prostate plans. Methods: Compass is capable of calculating dose as secondary check from DICOM TPS data and reconstructing it from measurements taken by a 2D ion chamber array (MatriXX Evolution, IBA Dosimetry). Both 2D and 3D gamma tests are available to compare calculated and reconstructed dose in Compass with TPS RT Dose. Results: 15 VMAT prostate plans have been measured with Compass. Dose is reconstructed with Compass for these plans. 2D gamma comparisons can be done for any plane from dose matrix. Mean gamma passing rates for isocenter planes (axial, coronal, sagittal) are (99.7±0.2)%, (99.9±0.1)%, (99.9±0.1)% for reconstructed dose planes. 3D mean gamma passing rates are (98.5±1.7)% for PTVs, (99.1±1.5)% for rectum, (100.0±0.0)% for bladder, (99.6±0.7)% for femoral heads and (98.1±4.1)% for penile bulb. Conclusion: Compass is a powerful tool to perform a complete pre-treatment QA analysis, from 2D techniques to 3D DVH-based techniques with clinical relevance. All reported values for VMAT prostate plans are in good agreement with TPS values. This system permits us to ensure the accuracy in the delivery of VMAT treatments completing a full patient-specific QA program.

  19. Prompt gamma-ray analysis using cold and thermal guided neutron beams at JAERI.

    PubMed

    Yonezawa, C

    1999-01-01

    A highly sensitive neutron-induced prompt gamma-ray analysis (PGA) system, usable at both cold and thermal neutron beam guides of JRR-3M, has been constructed. The system was designed to achieve the lowest gamma-ray background by using lithium fluoride tiles as neutron shielding, by placing the samples in a He atmosphere and by using a Ge-bismuth germanate detector system for Compton suppression. The gamma-ray spectrometer can acquire three modes of spectra simultaneously: single, Compton suppression, and pair modes. Because of the low-energy guided neutron beams and the low-background system, analytical sensitivities and detection limits better than those in usual PGA systems have been achieved. Boron and multielemental determination by a comparative standardization have been investigated, and accuracy, precision, and detection limits for the elements in various materials were evaluated. The system has been applied to the determination of B and multielements in samples of various fields such as medical, environmental, and geological sciences. PMID:10676516

  20. Gamma scintigraphic analysis of albumin flux in patients with acute respiratory distress syndrome

    SciTech Connect

    Sugerman, H.J.; Tatum, J.L.; Burke, T.S.; Strash, A.M.; Glauser, F.L.

    1984-06-01

    Computerized gamma-scintigraphy provides a new method for the analysis of albumin flux in patients with pulmonary permeability edema. In this technique, 10 mCi of /sup 99/mTc -tagged human serum albumin is administered and lung:heart radioactivity ratios are determined. This ratio remains constant unless there is a leak of albumin, when a rising ratio with time, called the ''slope index'' (SI), is seen. Thirty-five scintigraphic studies were obtained in 28 patients by means of a portable computerized gamma-camera. Thirteen of these patients had clinical evidence of the acute respiratory distress syndrome (ARDS) and six had or were recovering from left ventricular induced congestive heart failure (CHF). Five of the patients with CHF and pulmonary capillary wedge pressure (PCWP) below 30 mm Hg had normal scintigraphic studies. The patients with ARDS were found to have significantly higher SIs than patients who did not have, or had recovered from, ARDS. Positive SIs were present from 1 to 8 days following the apparent onset of ARDS in seven studies in five patients. Recovery of gas exchange was associated with a return to a normal SI in four patients. In conclusion, computerized gamma-scintigraphy was a sensitive, noninvasive tool for the detection of a pathologic increase in pulmonary protein flux. Positive scintigraphic findings were associated with significantly impaired gas exchange. The method documented that the leak of albumin in patients with ARDS may last for days but resolves with recovery.

  1. Prompt gamma neutron activation analysis of toxic elements in radioactive waste packages.

    PubMed

    Ma, J-L; Carasco, C; Perot, B; Mauerhofer, E; Kettler, J; Havenith, A

    2012-07-01

    The French Alternative Energies and Atomic Energy Commission (CEA) and National Radioactive Waste Management Agency (ANDRA) are conducting an R&D program to improve the characterization of long-lived and medium activity (LL-MA) radioactive waste packages. In particular, the amount of toxic elements present in radioactive waste packages must be assessed before they can be accepted in repository facilities in order to avoid pollution of underground water reserves. To this aim, the Nuclear Measurement Laboratory of CEA-Cadarache has started to study the performances of Prompt Gamma Neutron Activation Analysis (PGNAA) for elements showing large capture cross sections such as mercury, cadmium, boron, and chromium. This paper reports a comparison between Monte Carlo calculations performed with the MCNPX computer code using the ENDF/B-VII.0 library and experimental gamma rays measured in the REGAIN PGNAA cell with small samples of nickel, lead, cadmium, arsenic, antimony, chromium, magnesium, zinc, boron, and lithium to verify the validity of a numerical model and gamma-ray production data. The measurement of a ∼20kg test sample of concrete containing toxic elements has also been performed, in collaboration with Forschungszentrum Jülich, to validate the model in view of future performance studies for dense and large LL-MA waste packages. PMID:22406218

  2. Results of places data analysis. Technical report

    SciTech Connect

    Prettie, C.W.

    1982-09-01

    The results of analyses performed to support PLACES data reduction and data interpretation are presented. Beacon receiver measurements of the scattering of a 100 MHz pseudo-noise beacon signal BPSK modulated at a 10 MHz rate were made during an occultatation by the structured IRIS ion cloud. The scattering produced features in the received St. George Island signal that are shown to be in good quantitative agreement with propagation effect predictions produced from an optically derived model of the ion cloud extent. The features in the received data are also in qualitative agreement with the optical features in a coincident St. George Island photograph. Neutral wind shear rate is determined in the optical analyses to be directed with a 351 deg azimuth with a 1.5 meter per second per kilometer of altitude magnitude. Aircraft propagation measurements of the JAN ion cloud reveal a steady decay of the TEC until the cloud effects vanish at roughly 200 minutes after release. The following mechanism is proposed to explain late time barium cloud decay: Barium ions are removed from the ion cloud as current carriers and are replaced by molecular air ions which quickly recombine. The mechanism is found to be highly efficient. The kHz frequency spurs in the NRL density probe data from JAN are briefly investigated. The spur frequency is found to have no clear-cut dependence on local density, is not confined to the ion cloud region, and at times two spurs are visible in the data.

  3. A meta-analysis of leukaemia risk from protracted exposure to low-dose gamma radiation

    PubMed Central

    Schubauer-Berigan, M K

    2010-01-01

    Context More than 400 000 workers annually receive a measurable radiation dose and may be at increased risk of radiation-induced leukaemia. It is unclear whether leukaemia risk is elevated with protracted, low-dose exposure. Objective We conducted a meta-analysis examining the relationship between protracted low-dose ionising radiation exposure and leukaemia. Data sources Reviews by the National Academies and United Nations provided a summary of informative studies published before 2005. PubMed and Embase databases were searched for additional occupational and environmental studies published between 2005 and 2009. Study selection We selected 23 studies that: (1) examined the association between protracted exposures to ionising radiation and leukaemia excluding chronic lymphocytic subtype; (2) were a cohort or nested case–control design without major bias; (3) reported quantitative estimates of exposure; and (4) conducted exposure–response analyses using relative or excess RR per unit exposure. Methods Studies were further screened to reduce information overlap. Random effects models were developed to summarise between-study variance and obtain an aggregate estimate of the excess RR at 100 mGy. Publication bias was assessed by trim and fill and Rosenthal's file drawer methods. Results We found an ERR at 100 mGy of 0.19 (95% CI 0.07 to 0.32) by modelling results from 10 studies and adjusting for publication bias. Between-study variance was not evident (p=0.99). Conclusions Protracted exposure to low-dose gamma radiation is significantly associated with leukaemia. Our estimate agreed well with the leukaemia risk observed among exposed adults in the Life Span Study (LSS) of atomic bomb survivors, providing increased confidence in the current understanding of leukaemia risk from ionising radiation. However, unlike the estimates obtained from the LSS, our model provides a precise, quantitative summary of the direct estimates of excess risk from studies of

  4. An updated gamma-ray analysis of the Be-BH binary HD 215227

    NASA Astrophysics Data System (ADS)

    Alexander, Michael J.; McSwain, M. Virginia

    2015-05-01

    We report an updated analysis of the gamma-ray source AGL J2241+4454 that was detected as a brief two-day flare in 2010 by the AGILE satellite. The high-energy emission of AGL J2241+4454 has been attributed to the binary system HD 215227, which consists of a Be star being orbited by a black hole making it the first known Be-black hole binary system. We have analysed the AGILE data and find a gamma-ray flux of (1.8 ± 0.7) × 10-6 ph cm-2 s-1, in agreement with the initial report. Additionally, we examined data from the Fermi Large Area Telescope over several time intervals including the two-day flare, the folded orbital phase, and the entire mission (˜6 yr). We do not detect AGL J2241+4454 over any of these time periods with Fermi and find upper limits of 1.1 × 10-7 and 5.2 × 10-10 ph cm-2 s-1 for the flare and the full mission, respectively. We conclude that the HD 215227 Be-black hole binary is not a true gamma-ray binary as previously speculated. While analysing the Fermi data of the AGL J2241+4454 region, we discovered a previously unknown gamma-ray source with average flux of (13.56 ± 0.02) × 10-8 ph cm-2 s-1 that is highly variable on monthly time-scales. We associate this emission with the known quasar 87GB 215950.2+503417.

  5. Flexible ureterorenoscopy results: Analysis of 279 cases

    PubMed Central

    Elbir, Fatih; Başıbüyük, İsmail; Topaktaş, Ramazan; Kardaş, Sina; Tosun, Muhammed; Tepeler, Abdulkadir; Armağan, Abdullah

    2015-01-01

    Objective In this study, the outcomes of 279 cases in whom we performed retrograde intrarenal surgery (RIRS) were evaluated retrospectively. Material and methods RIRS was performed on 279 cases with the aid of access sheath of guidewire between March 2011 and February 2015. All patients were operated in the standard lithotomy position. A hydrophilic guidewire was inserted with the aid of rigid ureterorenoscopy and we checked whether there were any residual ureteral stones and other pathologies. Fluoroscopy was used routinely in all cases. Stone fragments smaller than 3 mm were left off but those bigger than 3 mm were removed by grasper after stone fragmentation. Controls of the patients were assessed by plain films (KUB), urinary tract ultrasonography (US) and/or computed tomography (CT) 1 month after the operation. Success rate of the procedure was defined as the stone-free status or presence of residual fragments less than 3 mm. Results 152 of the patients were male and 127 were female. The median ages of the male and female patients were 47.7 (1–86) ve 45.9 (3–79) years respectively. The median stone size was 13.5 mm (8–25). Preoperatively 34 (12.1%) patients had double-J ureteral stent. 19 (6.8%) patients were operated while they were still receiving antithrombotic and antiplatelet therapy Solitary kidney was present in 24 patients while the remaining patients had kyphoscoliosis (n=3), rotation anomaly (n=6), pelvic kidney (n=2), double collecting system (n=3), and horseshoe kidney (n=6). In 264 patients access sheath was used, in 15 patients operation was performed with the help of the guidewire. Double-J stents were inserted to 14 patients because of ureteral stricture and they underwent operation after 2 weeks later. Renal stones of 219 patients among all cases were fragmented completely and the patients were discharged as stone free (SF). Our success rate (SF or presence of clinically insignificant residual [CIRF]) was 78.4%. Stone size (p=0

  6. The results of the in-flight attitude sensor calibration for the Arthur Holly Compton Gamma Ray Observatory

    NASA Technical Reports Server (NTRS)

    Davis, W. S.; Eudell, A. H.; Kulp, L. S.; Lindrose, L. A.; Harman, R. R.

    1993-01-01

    The Arthur Holly Compton Gamma Ray Observatory (GRO) was launched by the shuttle Atlantis in April 1991. This paper presents the results of the attitude sensor calibration that was performed during the early mission. The GSFC Flight Dynamics Facility (FDF) performed an alignment calibration of the two fixed-head star trackers (FHST's) and two fine Sun sensors (FSS's) on board Compton GRO. The results show a 27-arcsecond shift between the bore sights of the FHST's with respect to prelaunch measurements. The alignments of the two FSS's shifted by 0.20 and 0.05 degree. During the same time period, the Compton GRO science teams performed an alignment calibration of the science instruments with respect to the attitude reported by the on board computer (OBC). In order to preserve these science alignments, FDF adjusted the overall alignments of the FHST's and FSS's, obtained by the FDF calibration, such that when up linked to the OBC, the shift in the OBC-determined attitude is minimized. FDF also calibrated the inertial reference unit (IRU), which consists of three dual-axis gyroscopes. The observed gyro bias matched the bias that was solved for by the OBC. This bias drifted during the first 6 days after release. The results of the FDF calibration of scale factor and alignment shifts showed changes that were of the same order as their uncertainties.

  7. The results of the in-flight attitude sensor calibration for the Arthur Holly Compton Gamma Ray Observatory

    NASA Astrophysics Data System (ADS)

    Davis, W. S.; Eudell, A. H.; Kulp, L. S.; Lindrose, L. A.; Harman, R. R.

    1993-02-01

    The Arthur Holly Compton Gamma Ray Observatory (GRO) was launched by the shuttle Atlantis in April 1991. This paper presents the results of the attitude sensor calibration that was performed during the early mission. The GSFC Flight Dynamics Facility (FDF) performed an alignment calibration of the two fixed-head star trackers (FHST's) and two fine Sun sensors (FSS's) on board Compton GRO. The results show a 27-arcsecond shift between the bore sights of the FHST's with respect to prelaunch measurements. The alignments of the two FSS's shifted by 0.20 and 0.05 degree. During the same time period, the Compton GRO science teams performed an alignment calibration of the science instruments with respect to the attitude reported by the on board computer (OBC). In order to preserve these science alignments, FDF adjusted the overall alignments of the FHST's and FSS's, obtained by the FDF calibration, such that when up linked to the OBC, the shift in the OBC-determined attitude is minimized. FDF also calibrated the inertial reference unit (IRU), which consists of three dual-axis gyroscopes. The observed gyro bias matched the bias that was solved for by the OBC. This bias drifted during the first 6 days after release. The results of the FDF calibration of scale factor and alignment shifts showed changes that were of the same order as their uncertainties.

  8. Exact error rate analysis of free-space optical communications with spatial diversity over Gamma-Gamma atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Ma, Jing; Li, Kangning; Tan, Liying; Yu, Siyuan; Cao, Yubin

    2016-02-01

    The error rate performances and outage probabilities of free-space optical (FSO) communications with spatial diversity are studied for Gamma-Gamma turbulent environments. Equal gain combining (EGC) and selection combining (SC) diversity are considered as practical schemes to mitigate turbulence. The exact bit-error rate (BER) expression and outage probability are derived for direct detection EGC multiple aperture receiver system. BER performances and outage probabilities are analyzed and compared for different number of sub-apertures each having aperture area A with EGC and SC techniques. BER performances and outage probabilities of a single monolithic aperture and multiple aperture receiver system with the same total aperture area are compared under thermal-noise-limited and background-noise-limited conditions. It is shown that multiple aperture receiver system can greatly improve the system communication performances. And these analytical tools are useful in providing highly accurate error rate estimation for FSO communication systems.

  9. Analysis and Preliminary Results of The NPDGamma Experiment

    NASA Astrophysics Data System (ADS)

    Fry, Jason

    2014-03-01

    The NPDGamma Experiment measures the parity violating gamma asymmetry from polarized neutrons captured on protons at the Spallation Neutron Source at ORNL. The parity violating asymmetry Aγ between the neutron spin and the photon momentum is proportional to the ΔI = 1 long range weak meson coupling hπ1 between nucleons in the hadronic weak interaction. Liquid para-hydrogen production data has been taken since May 2012 and will continue in 2014 to measure Aγ to a precision of 1 ×10-8. Various aspects of the experiment, preliminary results, and plans to complete NPDGamma in 2014 will be discussed.

  10. Isotopic analysis of uranium in U3O8 by passive gamma-ray spectrometry

    PubMed

    Nir-El

    2000-03-01

    Passive gamma-ray spectrometry was applied to analyze the isotopic composition of uranium in U3O8. Depleted and enriched U3O8 standard reference materials were used to calibrate the system. An independent calibration was performed by standard gamma-ray point sources. U3O8 SRM samples of the 950 series were analyzed. The present results show that the isotopic abundances of 235U in SRMs 950, 950a and 950b are higher by +3.6, +0.9 and +0.9% (relative deviation) than the natural value 0.7200%, while relative precisions were +/-0.4, +/-0.7 and +/-0.3%, respectively. PMID:10724436

  11. Gamma-ray spectrometry analysis of pebble bed reactor fuel using Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Chen, Jianwei; Hawari, Ayman I.; Zhao, Zhongxiang; Su, Bingjing

    2003-06-01

    Monte Carlo simulations were used to study the gamma-ray spectra of pebble bed reactor fuel at various levels of burnup. A fuel depletion calculation was performed using the ORIGEN2.1 code, which yielded the gamma-ray source term that was introduced into the input of an MCNP4C simulation. The simulation assumed the use of a 100% efficient high-purity coaxial germanium (HPGe) detector, a pebble placed at a distance of 100 cm from the detector, and accounted for Gaussian broadening of the gamma-ray peaks. Previously, it was shown that 137Cs, 60Co (introduced as a dopant), and 134Cs are the relevant burnup indicators. The results show that the 662 keV line of 137Cs lies in close proximity to the intense 658 keV of 197Nb, which results in spectral interference between the lines. However, the 1333 keV line of 60Co, and selected 134Cs lines (e.g., at 605 keV) are free from spectral interference, which enhances the possibility of their utilization as relative burnup indicators.

  12. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1991-01-01

    Miscellaneous tasks related to the development of the Burst and Transient Source Experiment on the Gamma Ray Observatory and to collection, analysis, and interpretation of data from the MSFC Very Low Frequency transient monitoring program were performed. The results are summarized and relevant references are included.

  13. Magnetic Microcalorimeter Gamma Detectors for High-Precision Non-Destructive Analysis, FY14 Extended Annual Report

    SciTech Connect

    Friedrich, S.

    2015-02-06

    Cryogenic gamma (γ) detectors with operating temperatures of ~0.1 K or below offer 10× better energy resolution than conventional high-purity germanium detectors that are currently used for non-destructive analysis (NDA) of nuclear materials. This can greatly increase the accuracy of NDA, especially at low-energies where gamma rays often have similar energies and cannot be resolved by Ge detectors. We are developing cryogenic γ–detectors based on metallic magnetic calorimeters (MMCs), which have the potential of higher resolution, faster count rates and better linearity than other cryogenic detector technologies. High linearity is essential to add spectra from different pixels in detector arrays that are needed for high sensitivity. Here we discuss the fabrication of a new generation of MMC γ–detectors in FY2014, and the resulting improvements in energy resolution and linearity of the new design. As an example of the type of NDA that cryogenic detectors enable, we demonstrate the direct detection of Pu-242 emissions with our MMC γ–detectors in the presence of Pu-240, and show that a quantitative NDA analysis agrees with the mass spectrometry

  14. Determination of hydrogen in metals, semiconductors, and other materials by cold neutron prompt gamma-ray activation analysis

    SciTech Connect

    Paul, R.L.; Lindstrom, R.M.

    1998-12-31

    Cold neutron prompt gamma-ray activation analysis has proven useful for nondestructive measurement of trace hydrogen. The sample is irradiated in a beam of neutrons; the presence of hydrogen is confirmed by the emission of a 2223 keV gamma-ray. Detection limits for hydrogen are 3 mg/kg in quartz and 8 mg/kg in titanium. The authors have used the technique to measure hydrogen in titanium alloys, germanium, quartz, fullerenes and their derivatives, and other materials.

  15. Microbial analysis and survey test of gamma-irradiated freeze-dried fruits for patient's food

    NASA Astrophysics Data System (ADS)

    Park, Jae-Nam; Sung, Nak-Yun; Byun, Eui-Hong; Byun, Eui-Baek; Song, Beom-Seok; Kim, Jae-Hun; Lee, Kyung-A.; Son, Eun-Joo; Lyu, Eun-Soon

    2015-06-01

    This study examined the microbiological and organoleptic qualities of gamma-irradiated freeze-dried apples, pears, strawberries, pineapples, and grapes, and evaluated the organoleptic acceptability of the sterilized freeze-dried fruits for hospitalized patients. The freeze-dried fruits were gamma-irradiated at 0, 1, 2, 3, 4, 5, 10, 12, and 15 kGy, and their quality was evaluated. Microorganisms were not detected in apples after 1 kGy, in strawberries and pears after 4 kGy, in pineapples after 5 kGy, and in grapes after 12 kGy of gamma irradiation. The overall acceptance score, of the irradiated freeze-dried fruits on a 7-point scale at the sterilization doses was 5.5, 4.2, 4.0, 4.1, and 5.1 points for apples, strawberries, pears, pineapples, and grapes, respectively. The sensory survey of the hospitalized cancer patients (N=102) resulted in scores of 3.8, 3.7, 3.9, 3.9, and 3.7 on a 5-point scale for the gamma-irradiated freeze-dried apples, strawberries, pears, pineapples, and grapes, respectively. The results suggest that freeze-dried fruits can be sterilized with a dose of 5 kGy, except for grapes, which require a dose of 12 kGy, and that the organoleptic quality of the fruits is acceptable to immuno-compromised patients. However, to clarify the microbiological quality and safety of freeze-dried fruits should be verified by plating for both aerobic and anaerobic microorganisms.

  16. In vivo Prompt Gamma Neutron Activation Analysis Facility for Total Body Nitrogen and Cd

    SciTech Connect

    Munive, Marco; Revilla, Angel; Solis, Jose L.

    2007-10-26

    A Prompt Gamma Neutron Activation Analysis (PGNAA) system has been designed and constructed to measure the total body nitrogen and Cd for in vivo studies. An aqueous solution of KNO{sub 3} was used as phantom for system calibration. The facility has been used to monitor total body nitrogen (TBN) of mice and found that is related to their diet. Some mice swallowed diluted water with Cl{sub 2}Cd, and the presence of Cd was detected in the animals. The minimum Cd concentration that the system can detect was 20 ppm.

  17. Gamma-ray spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Arnold, J. R.; Peterson, L. E.; Metzger, A. E.; Trombka, J. I.

    1972-01-01

    The experiments in gamma-ray spectrometry to determine the geochemical composition of the lunar surface are reported. The theory is discussed of discrete energy lines of natural radioactivity, and the lines resulting from the bombardment of the lunar surface by high energy cosmic rays. The gamma-ray spectrometer used in lunar orbit and during transearth coast is described, and a preliminary analysis of the results is presented.

  18. Test 6, Test 7, and Gas Standard Analysis Results

    NASA Technical Reports Server (NTRS)

    Perez, Horacio, III

    2007-01-01

    This viewgraph presentation shows results of analyses on odor, toxic off gassing and gas standards. The topics include: 1) Statistical Analysis Definitions; 2) Odor Analysis Results NASA Standard 6001 Test 6; 3) Toxic Off gassing Analysis Results NASA Standard 6001 Test 7; and 4) Gas Standard Results NASA Standard 6001 Test 7;

  19. Interferon Gamma Release Assays for Diagnosis of Pleural Tuberculosis: a Systematic Review and Meta-Analysis

    PubMed Central

    Agarwal, Ritesh; Gupta, Dheeraj; Dhooria, Sahajal; Behera, Digambar

    2015-01-01

    The role of interferon gamma release assays (IGRAs), although established for identifying latent tuberculosis, is still evolving in the diagnosis of active extrapulmonary tuberculosis. We systematically evaluated the diagnostic performance of blood- and pleural fluid-based IGRAs in tuberculous pleural effusion (TPE). We searched the PubMed and Embase databases for studies evaluating the use of commercially available IGRAs on blood and/or pleural fluid samples for diagnosing TPE. The quality of the studies included was assessed through the QUADAS-2 tool. The pooled estimates of sensitivity and specificity with 95% confidence intervals (95% CI) were generated using a bivariate random-effects model and examined using forest plots and hierarchical summary receiver operating characteristic (HSROC) curves. Indeterminate IGRA results were included for sensitivity calculations. Heterogeneity was explored through subgroup analysis and meta-regression based on prespecified covariates. We identified 19 studies assessing the T.SPOT.TB and/or QuantiFERON assays. There were 20 and 14 evaluations, respectively, of whole-blood and pleural fluid assays, involving 1,085 and 727 subjects, respectively. There was only one good-quality study, and five studies used nonstandard assay thresholds. The pooled sensitivity and specificity for the blood assays were 0.77 (95% CI, 0.71 to 0.83) and 0.71 (95% CI, 0.65 to 0.76), respectively. The pooled sensitivity and specificity for the pleural fluid assays were 0.72 (95% CI, 0.55 to 0.84) and 0.78 (95% CI, 0.65 to 0.87), respectively. There was considerable heterogeneity; however, multivariate meta-regression did not identify any covariate with significant influence. There was no publication bias for blood assays. We conclude that commercial IGRAs, performed either on whole-blood or pleural fluid samples, have poor diagnostic accuracy in patients suspected to have TPE. PMID:25994163

  20. Spectral analysis of shielded gamma ray sources using precalculated library data

    NASA Astrophysics Data System (ADS)

    Holmes, Thomas Wesley; Gardner, Robin P.

    2015-11-01

    In this work, an approach has been developed for determining the intensity of a shielded source by first determining the thicknesses of three different shielding materials from a passively collected gamma-ray spectrum by making comparisons with predetermined shielded spectra. These evaluations are dependent on the accuracy and validity of the predetermined library spectra which were created by changing the thicknesses of the three chosen materials lead, aluminum and wood that are used to simulate any actual shielding. Each of the spectra produced was generated using MCNP5 with a sufficiently large number of histories to ensure a low relative error at each channel. The materials were held in the same respective order from source to detector, where each material consisted of three individual thicknesses and a null condition. This then produced two separate data sets of 27 total shielding material situations and subsequent predetermined libraries that were created for each radionuclide source used. The technique used to calculate the thicknesses of the materials implements a Levenberg-Marquardt nonlinear search that employs a tri-linear interpolation with the respective predetermined libraries within each channel for the supplied input unknown spectrum. Given that the nonlinear parameters require an initial guess for the calculations, the approach demonstrates first that when the correct values are input, the correct thicknesses are found. It then demonstrates that when multiple trials of random values are input for each of the nonlinear parameters, the average of the calculated solutions that successfully converges also produced the correct thicknesses. Under situations with sufficient information known about the detection situation at hand, the method was shown to behave in a manner that produces reasonable results and can serve as a good preliminary solution. This technique has the capability to be used in a variety of full spectrum inverse analysis problems

  1. Report on the analysis of common beverages spiked with gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL) using NMR and the PURGE solvent-suppression technique.

    PubMed

    Lesar, Casey T; Decatur, John; Lukasiewicz, Elaan; Champeil, Elise

    2011-10-10

    In forensic evidence, the identification and quantitation of gamma-hydroxybutyric acid (GHB) in "spiked" beverages is challenging. In this report, we present the analysis of common alcoholic beverages found in clubs and bars spiked with gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL). Our analysis of the spiked beverages consisted of using (1)H NMR with a water suppression method called Presaturation Utilizing Relaxation Gradients and Echoes (PURGE). The following beverages were analyzed: water, 10% ethanol in water, vodka-cranberry juice, rum and coke, gin and tonic, whisky and diet coke, white wine, red wine, and beer. The PURGE method allowed for the direct identification and quantitation of both compounds in all beverages except red and white wine where small interferences prevented accurate quantitation. The NMR method presented in this paper utilizes PURGE water suppression. Thanks to the use of a capillary internal standard, the method is fast, non-destructive, sensitive and requires no sample preparation which could disrupt the equilibrium between GHB and GBL. PMID:21775083

  2. Analysis of Gamma-Ray Data from Solar Flares in Cycles 21 and 22

    NASA Technical Reports Server (NTRS)

    Vestrand, W. Thomas

    1998-01-01

    One of our primary accomplishments under grant NAGW-35381 was the systematic derivation and compilation, for the first time, of physical parameters for all gamma-ray flares detected by the SMM GRS during its ten year lifetime. The flare parameters derived from the gamma-ray spectra include: bremsstrahlung fluence and best-fit power-law parameters, narrow nuclear line fluence, positron annihilation line fluence, neutron capture line fluence, and an indication of whether or not greater than 10 MeV emissions were present. We combined this compilation of flare parameters with our plots of counting rate time histories and flare spectra to construct an atlas of gamma-ray flare characteristics. The atlas time histories display four energy bands: 56-199 kev, 298526 keV, 4-8 MeV, and 10-25 MeV. These energy bands respectively measure nonrelativistic bremsstrahlung, trans-relativistic bremsstrahlung, nuclear de-excitation, and ultra-relativistic bremsstrahlung. The atlas spectra show the integrated high-energy spectra measured for all GRS flares and dissects them into electron bremsstrahlung, positron annihilation and nuclear emission components. The atlas has been accepted for publication in the Astrophysical Journal Supplements and is currently in press. The atlas materials were also supplied to the Solar Data Analysis Center at Goddard Space Flight Center and were made available through a web site at the University of New Hampshire. Since a uniform methodology was adopted for deriving the flare parameters, this atlas will be very useful for future statistical and correlative studies of solar flares-three independent groups are presently using it to correlate interplanetary energetic particle measurements with our gamma-ray measurements. A better model for the response of the GRS instrument to high energy radiation was also developed. A refined response model was needed because the old model was not adequate for predicting the first and second escape peaks associated with

  3. GRABGAM: A Gamma Analysis Code for Ultra-Low-Level HPGe SPECTRA

    SciTech Connect

    Winn, W.G.

    1999-07-28

    The GRABGAM code has been developed for analysis of ultra-low-level HPGe gamma spectra. The code employs three different size filters for the peak search, where the largest filter provides best sensitivity for identifying low-level peaks and the smallest filter has the best resolution for distinguishing peaks within a multiplet. GRABGAM basically generates an integral probability F-function for each singlet or multiplet peak analysis, bypassing the usual peak fitting analysis for a differential f-function probability model. Because F is defined by the peak data, statistical limitations for peak fitting are avoided; however, the F-function does provide generic values for peak centroid, full width at half maximum, and tail that are consistent with a Gaussian formalism. GRABGAM has successfully analyzed over 10,000 customer samples, and it interfaces with a variety of supplementary codes for deriving detector efficiencies, backgrounds, and quality checks.

  4. A portable medium-resolution gamma-ray spectrometer and analysis software

    SciTech Connect

    Lavietes, A.D.; McQuaid, J.H.; Ruhter, W.D.; Buckley, W.M.; Clark, D-L.; Paulus, T.J.

    1996-07-01

    There is a strong need for portable radiometric instrumentation that can both accurately confirm the presence of nuclear materials and allow isotopic analysis of radionuclides in the field. To fulfill this need the Safeguards Technology Program at LLNL has developed a hand-held, non-cryogenic, low-power gamma-ray and x-ray measurements and analysis instrument that can both search for and then accurately verify the presence of nuclear materials. We will report on the use of cadmium zinc telluride (CZT) detectors, detector electronics, and the new field-portable instrument being developed. We will also describe the isotopic analysis that allows enrichment measurements to be made accurately in the field. These systems provide capability for safeguards inspection and verification applications and could find application in counter-smuggling operations.

  5. The Prompt Gamma Neutron Activation Analysis Facility at ICN-Pitesti

    SciTech Connect

    Barbos, D.; Paunoiu, C.; Mladin, M.; Cosma, C.

    2008-08-14

    PGNAA is a very widely applicable technique for determining the presence and amount of many elements simultaneously in samples ranging in size from micrograms to many grams. PGNAA is characterized by its capability for nondestructive multi-elemental analysis and its ability to analyse elements that cannot be determined by INAA. By means of this PGNAA method we are able to increase the performance of INAA method. A facility has been developed at Institute for Nuclear Research-Pitesti so that the unique features of prompt gamma-ray neutron activation analysis can be used to measure trace and major elements in samples. The facility is linked at the radial neutron beam tube at ACPR-TRIGA reactor. During the PGNAA-facility is in use the ACPR reactor will be operated in steady-state mode at 250 KW maximum power. The facility consists of a radial beam-port, external sample position with shielding, and induced prompt gamma-ray counting system.Thermal neutron flux with energy lower than cadmium cut-off at the sample position was measured using thin gold foil is: {phi}{sub scd} = 1.10{sup 6} n/cm{sup 2}/s with a cadmium ratio of:80.The gamma-ray detection system consist of an HpGe detector of 16% efficiency (detector model GC1518) with 1.85 keV resolution capability. The HpGe is mounted with its axis at 90 deg. with respect to the incident neutron beam at distance about 200mm from the sample position. To establish the performance capabilities of the facility, irradiation of pure element or sample compound standards were performed to identify the gama-ray energies from each element and their count rates.

  6. Assessment of measurement result uncertainty in determination of (210)Pb with the focus on matrix composition effect in gamma-ray spectrometry.

    PubMed

    Iurian, A R; Pitois, A; Kis-Benedek, G; Migliori, A; Padilla-Alvarez, R; Ceccatelli, A

    2016-03-01

    Reference materials were used to assess measurement result uncertainty in determination of (210)Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter (210)Po in radioactive equilibrium. Combined standard uncertainties of (210)Pb massic activities obtained by liquid scintillation counting are in the range 2-12%, depending on matrices and massic activity values. They are in the range 1-3% for the measurement of its daughter (210)Po using alpha-particle spectrometry. Three approaches (direct computation of counting efficiency and efficiency transfer approaches based on the computation and, respectively, experimental determination of the efficiency transfer factors) were applied for the evaluation of (210)Pb using gamma-ray spectrometry. Combined standard uncertainties of gamma-ray spectrometry results were found in the range 2-17%. The effect of matrix composition on self-attenuation was investigated and a detailed assessment of uncertainty components was performed. PMID:26653212

  7. Scalable analysis tools for sensitivity analysis and UQ (3160) results.

    SciTech Connect

    Karelitz, David B.; Ice, Lisa G.; Thompson, David C.; Bennett, Janine C.; Fabian, Nathan; Scott, W. Alan; Moreland, Kenneth D.

    2009-09-01

    The 9/30/2009 ASC Level 2 Scalable Analysis Tools for Sensitivity Analysis and UQ (Milestone 3160) contains feature recognition capability required by the user community for certain verification and validation tasks focused around sensitivity analysis and uncertainty quantification (UQ). These feature recognition capabilities include crater detection, characterization, and analysis from CTH simulation data; the ability to call fragment and crater identification code from within a CTH simulation; and the ability to output fragments in a geometric format that includes data values over the fragments. The feature recognition capabilities were tested extensively on sample and actual simulations. In addition, a number of stretch criteria were met including the ability to visualize CTH tracer particles and the ability to visualize output from within an S3D simulation.

  8. Understanding Doppler Broadening of Gamma Rays

    SciTech Connect

    Rawool-Sullivan, Mohini; Sullivan, John P.

    2014-07-03

    Doppler-broadened gamma ray peaks are observed routinely in the collection and analysis of gamma-ray spectra. If not recognized and understood, the appearance of Doppler broadening can complicate the interpretation of a spectrum and the correct identification of the gamma ray-emitting material. We have conducted a study using a simulation code to demonstrate how Doppler broadening arises and provide a real-world example in which Doppler broadening is found. This report describes that study and its results.

  9. mBAND Analysis of Late Chromosome Aberrations in Human Lymphocytes Induced by Gamma Rays and Fe Ions

    NASA Technical Reports Server (NTRS)

    Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2014-01-01

    Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

  10. Ablation of the 14-3-3gamma Protein Results in Neuronal Migration Delay and Morphological Defects in the Developing Cerebral Cortex.

    PubMed

    Wachi, Tomoka; Cornell, Brett; Marshall, Courtney; Zhukarev, Vladimir; Baas, Peter W; Toyo-Oka, Kazuhito

    2016-06-01

    14-3-3 proteins are ubiquitously-expressed and multifunctional proteins. There are seven isoforms in mammals with a high level of homology, suggesting potential functional redundancy. We previously found that two of seven isoforms, 14-3-3epsilon and 14-3-3zeta, are important for brain development, in particular, radial migration of pyramidal neurons in the developing cerebral cortex. In this work, we analyzed the function of another isoform, the protein 14-3-3gamma, with respect to neuronal migration in the developing cortex. We found that in utero 14-3-3gamma-deficiency resulted in delays in neuronal migration as well as morphological defects. Migrating neurons deficient in 14-3-3gamma displayed a thicker leading process stem, and the basal ends of neurons were not able to reach the boundary between the cortical plate and the marginal zone. Consistent with the results obtained from in utero electroporation, time-lapse live imaging of brain slices revealed that the ablation of the 14-3-3gamma proteins in pyramidal neurons slowed down their migration. In addition, the 14-3-3gamma deficient neurons showed morphological abnormalities, including increased multipolar neurons with a thicker leading processes stem during migration. These results indicate that the 14-3-3gamma proteins play an important role in radial migration by regulating the morphology of migrating neurons in the cerebral cortex. The findings underscore the pathological phenotypes of brain development associated with the disruption of different 14-3-3 proteins and will advance the preclinical data regarding disorders caused by neuronal migration defects. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 600-614, 2016. PMID:26297819

  11. Spectrophotometric analysis of gamma-ray burst afterglow extinction curves with X-Shooter

    NASA Astrophysics Data System (ADS)

    Japelj, J.; Covino, S.; Gomboc, A.; Vergani, S. D.; Goldoni, P.; Selsing, J.; Cano, Z.; D'Elia, V.; Flores, H.; Fynbo, J. P. U.; Hammer, F.; Hjorth, J.; Jakobsson, P.; Kaper, L.; Kopač, D.; Krühler, T.; Melandri, A.; Piranomonte, S.; Sánchez-Ramírez, R.; Tagliaferri, G.; Tanvir, N. R.; de Ugarte Postigo, A.; Watson, D.; Wijers, R. A. M. J.

    2015-07-01

    We use gamma-ray burst (GRB) afterglow spectra observed with the VLT/X-Shooter spectrograph to measure rest-frame extinction in GRB lines-of-sight by modelling the broadband near-infrared (NIR) to X-ray afterglow spectral energy distributions (SEDs). Our sample consists of nine Swift GRBs, of which eight belong to the long-duration and one to the short-duration class. Dust is modelled using the average extinction curves of the Milky Way and the two Magellanic Clouds. We derive the rest-frame extinction of the entire sample, which fall in the range 0 ≲ AV ≲ 1.2. Moreover, the SMC extinction curve is the preferred extinction curve template for the majority of our sample, a result that is in agreement with those commonly observed in GRB lines of sights. In one analysed case (GRB 120119A), the common extinction curve templates fail to reproduce the observed extinction. To illustrate the advantage of using the high-quality, X-Shooter afterglow SEDs over the photometric SEDs, we repeat the modelling using the broadband SEDs with the NIR-to-UV photometric measurements instead of the spectra. The main result is that the spectroscopic data, thanks to a combination of excellent resolution and coverage of the blue part of the SED, are more successful in constraining extinction curves and therefore dust properties in GRB hosts with respect to photometric measurements. In all cases but one the extinction curve of one template is preferred over the others. We show that themodelled values of the extinction AV and the spectral slope, obtained through spectroscopic and photometric SED analysis, can differ significantly for individual events, though no apparent trend in the differences is observed. Finally we stress that, regardless of the resolution of the optical-to-NIR data, the SED modelling gives reliable results only when the fit is performed on a SED covering a broader spectral region (in our case extending to X-rays). Based on observations collected at the European

  12. An analysis of the Kalman filter in the Gamma Ray Observatory (GRO) onboard attitude determination subsystem

    NASA Technical Reports Server (NTRS)

    Snow, Frank; Harman, Richard; Garrick, Joseph

    1988-01-01

    The Gamma Ray Observatory (GRO) spacecraft needs a highly accurate attitude knowledge to achieve its mission objectives. Utilizing the fixed-head star trackers (FHSTs) for observations and gyroscopes for attitude propagation, the discrete Kalman Filter processes the attitude data to obtain an onboard accuracy of 86 arc seconds (3 sigma). A combination of linear analysis and simulations using the GRO Software Simulator (GROSS) are employed to investigate the Kalman filter for stability and the effects of corrupted observations (misalignment, noise), incomplete dynamic modeling, and nonlinear errors on Kalman filter. In the simulations, on-board attitude is compared with true attitude, the sensitivity of attitude error to model errors is graphed, and a statistical analysis is performed on the residuals of the Kalman Filter. In this paper, the modeling and sensor errors that degrade the Kalman filter solution beyond mission requirements are studied, and methods are offered to identify the source of these errors.

  13. Partial wave analysis of the reaction gamma p -> p omega$ and the search for nucleon resonances

    SciTech Connect

    M. Williams, D. Applegate, M. Bellis, C.A. Meyer

    2009-12-01

    An event-based partial wave analysis (PWA) of the reaction gamma p -> p omega has been performed on a high-statistics dataset obtained using the CLAS at Jefferson Lab for center-of-mass energies from threshold up to 2.4 GeV. This analysis benefits from access to the world's first high precision spin density matrix element measurements, available to the event-based PWA through the decay distribution of omega-> pi+ pi - pi0. The data confirm the dominance of the t-channel pi0 exchange amplitude in the forward direction. The dominant resonance contributions are consistent with the previously identified states F[15](1680) and D[13](1700) near threshold, as well as the G[17](2190) at higher energies. Suggestive evidence for the presence of a J(P)=5/2(+) state around 2 GeV, a "missing" state, has also been found. Evidence for other states is inconclusive.

  14. Cyclic oxidation behavior of beta+gamma overlay coatings on gamma and gamma+gamma-prime alloys

    NASA Technical Reports Server (NTRS)

    Nesbitt, J. A.; Pilsner, B. H.; Carol, L. A.; Heckel, R. W.

    1984-01-01

    Detailed experimental studies of the cyclic oxidation behavior of low-pressure plasma sprayed beta+gamma coasting on gamma-phase Ni-Cr-Al alloys have shown the correlation of weight change, oxide type, and Cr and Al concentration-distance profiles as a function of oxidation time. Of special interest was the transition to breakway oxidation due to the loss of the Al flux to the oxide and the failure of the coated alloy to form an Al2O3-rich oxide scale. The experimental results on beta+gamma/gamma coating systems were used as the basis of a numerical model (ternary, semi-infinite, finite-difference analysis) which accurately predicted changes in Cr and Al concentration-distance profiles. The model was used to study parameters critical to enhancing the life of coatings which fail by a combination of Al loss in forming the oxide scale and Al loss via interdiffusion with the substrate alloy. Comparisons of beta+gamma/gamma coating behavior are made to the oxidation of coated gamma+gamma-prime substrates, both ternary Ni-Cr-Al alloys and Mar-M 247-type alloys.

  15. First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10

    SciTech Connect

    Yoshikawa, M. Nagasu, K.; Shimamura, Y.; Shima, Y.; Kohagura, J.; Sakamoto, M.; Nakashima, Y.; Imai, T.; Ichimura, M.; Yasuhara, R.; Yamada, I.; Funaba, H.; Kawahata, K.; Minami, T.

    2014-11-15

    A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system.

  16. Quantitative analysis of gamma-ray emitters radioisotopes in commercialised bottled water in Tunisia.

    PubMed

    Ben Fredj, A; Hizem, N; Chelbi, M; Ghedira, L

    2005-01-01

    A set of measurements have been conducted in order to determine the annual effective dose resulting from the ingestion of natural radionuclides present in eight different brands of bottled water commercialised in Tunisia. Using high-resolution gamma spectrometry technique, we have noted the presence of the following radionuclides: 214Bi, 226Ra, 228Ac, 212Pb, 235U and 40K. For all classes of age, only the radium concentration was found to be significant in the calculation of the equivalent dose. Some of the studied samples exceeded the reference level of 0.1 mSv y(-1) of effective dose. PMID:15985499

  17. Results of calculations of external gamma radiation exposure rates from local fallout and the related radionuclide compositions of two hypothetical 1-MT nuclear bursts. Final report

    SciTech Connect

    Hicks, H.

    1984-12-01

    This report presents data on calculated gamma radiation exposure rates and local surface deposition of related radionuclides resulting from two hypothetical 1-Mt nuclear bursts. Calculations are made of the debris from two types of bombs: one containing /sup 235/U as a fissionable material (designated oralloy), the other containing /sup 238/U (designated tuballoy). 4 references.

  18. Gamma-ray and neutron radiography for a pulsed fast- neutron analysis cargo inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, Joel Christian

    1999-11-01

    This dissertation presents the design, optimization, and characterization of a gamma-ray and neutron radiographic subsystem that was developed for the Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. The PFNA inspection system uses nanosecond pulsed neutrons to produce three-dimensional elemental density images of cargo. Contraband in the cargo can be detected by its elemental content. The PFNA neutron source produces gamma rays as well as neutrons. The radiographic subsystem measures these radiations in an array of plastic scintillators to produce gamma-ray and neutron transmission images of the cargo simultaneously with the PFNA measurement. Although the radiographic subsystem improves PFNA performance in many forms of contraband detection, it was specifically designed to detect Special Nuclear Material (SNM) in cargo containers and trucks. A feasibility study, including experiments and modeling, was performed to determine the usefulness of gamma-ray radiography in this application. The study assumed a baseline configuration of the PFNA source, a relatively small rectangular radiation beam, and a plastic detector with a 5.1 cm diameter and a 7.6 cm length. The study showed that the baseline configuration was useful in cargoes up to 144 g/cm2 thick. At this thickness, a signal-to-noise ratio of three was obtainable per pixel. The maximum cargo thickness was later increased to 180 g/cm2 by increasing the detector length to 17.0 cm and by changing the source beam stop from gold to copper. An experiment was then performed that determined a 3.5 cm radiographic resolution was adequate for SNM detection. The detector configuration and the source motion were optimized to obtain a resolution of approximately 3.5 cm using the minimal number of detectors and the maximum detector diameter. The source is moved up and down as the cargo is pulled through the system to irradiate the entire surface of the cargo with the radiation beam. The final design consisted of

  19. The Multi-Isotope Process Monitor: Multivariate Analysis of Gamma Spectra

    SciTech Connect

    Orton, Christopher R.; Rutherford, Crystal E.; Fraga, Carlos G.; Schwantes, Jon M.

    2011-10-30

    The International Atomic Energy Agency (IAEA) has established international safeguards standards for fissionable material at spent fuel reprocessing plants to ensure that significant quantities of nuclear material are not diverted from these facilities. Currently, methods to verify material control and accountancy (MC&A) at these facilities require time-consuming and resource-intensive destructive assay (DA). The time delay between sampling and subsequent DA provides a potential opportunity to divert the material out of the appropriate chemical stream. Leveraging new on-line nondestructive assay (NDA) techniques in conjunction with the traditional and highly precise DA methods may provide a more timely, cost-effective and resource efficient means for MC&A verification at such facilities. Pacific Northwest National Laboratory (PNNL) is developing on-line NDA process monitoring technologies, including the Multi-Isotope Process (MIP) Monitor. The MIP Monitor uses gamma spectroscopy and pattern recognition software to identify off-normal conditions in process streams. Recent efforts have been made to explore the basic limits of using multivariate analysis techniques on gamma-ray spectra. This paper will provide an overview of the methods and report our on-going efforts to develop and demonstrate the technology.

  20. Characterization of HPGe gamma spectrometric detectors systems for Instrumental Neutron Activation Analysis (INAA) at the Colombian Geological Survey

    NASA Astrophysics Data System (ADS)

    Sierra, O.; Parrado, G.; Cañón, Y.; Porras, A.; Alonso, D.; Herrera, D. C.; Peña, M.; Orozco, J.

    2016-07-01

    This paper presents the progress made by the Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey (SGC in its Spanish acronym), towards the characterization of its gamma spectrometric systems for Instrumental Neutron Activation Analysis (INAA), with the aim of introducing corrections to the measurements by variations in sample geometry. Characterization includes the empirical determination of the interaction point of gamma radiation inside the Germanium crystal, through the application of a linear model and the use of a fast Monte Carlo N-Particle (MCNP) software to estimate correction factors for differences in counting efficiency that arise from variations in sample density between samples and standards.

  1. Furan formation from fatty acids as a result of storage, gamma irradiation, UV-C and heat treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furan is a possible human carcinogen that has been found in many thermally processed foods. The effects of thermal processing, gamma and UV-C irradiation on formation of furan from different fatty acids was studied. In addition, formation of furan from fatty acid emulsions during storage at 25C and...

  2. Stress analysis, thermomechanical fatique evaluation, and root subcomponent testing of gamma/gamma prime-delta eutectic alloy

    NASA Technical Reports Server (NTRS)

    Sheffler, K. D.; Jackson, J. J.

    1976-01-01

    Thermomechanical fatigue (TMF) and root subcomponent tensile, creep, and low cycle fatigue (LCF) tests were conducted to determine the capability of a fully lamellar directionally solidified eutectic alloy to sustain the airfoil thermal fatigue and root attachment loads anticipated in advanced, hollow, high work turbine blades. A three dimensional finite element elastic stress analysis was performed on typical advanced hollow eutectic airfoil and root-platform designs to determine appropriate conditions for these tests. Results of TMF tests conducted on longitudinal specimens (stress axis parallel to the solidification direction) containing a simulated leading edge cooling hole pattern indicated the longitudinal TMF properties to be more than adequate for the particular advanced hollow blade analyzed, with the strain range for a 10,000 cycle life being more than 50% above the maximum strain range calculated for the advanced hollow blade.

  3. Future Prospects for Space-Based Gamma Ray Astronomy

    NASA Astrophysics Data System (ADS)

    McConnell, Mark

    2015-04-01

    The gamma-ray sky offers a unique view into broad range of astrophysical phenomena, from nearby solar flares, to galactic pulsars, to gamma-ray bursts at the furthest reaches of the Universe. The Fermi mission has dramatically demonstrated the broad range of topics that can be addressed by gamma-ray observations. The full range of gamma-ray energies is quite broad, covering the electromagnetic spectrum at energies above about 100 keV. The energy range below several hundred GeV is the domain of space-based gamma-ray observatories, a range that is not completely covered by the Fermi LAT instrument. The gamma ray community has recently embarked on an effort to define the next steps for space-based gamma ray astronomy. These discussions are being facilitated through the Gamma-ray Science Interest Group (GammaSIG), which exists to provide community input to NASA in regards to current and future needs of the gamma-ray astrophysics community. The GammaSIG, as a part of the Physics of the Cosmos Program Analysis Group, provides a forum open to all members of the gamma-ray community. The GammaSIG is currently working to bring the community together with a common vision that will be expressed in the form of a community roadmap. This talk will summarize some of the latest results from active gamma ray observatories, including both Fermi and INTEGRAL, and will summarize the status of the community roadmap effort.

  4. Phantom experiment and calculation for in vivo 10boron analysis by prompt gamma ray spectroscopy.

    PubMed

    Matsumoto, T; Aoki, M; Aizawa, O

    1991-03-01

    In order to determine 10B concentrations in a tumour in vivo without injuring tissues, phantom experiments and calculations were carried out for boron neutron capture therapy. The experiment was based on prompt gamma ray spectroscopy and a single-crystal silicon-filtered neutron beam from a TRIGA-II reactor. Calibration curves to determine the 10B concentrations in the tumours were experimentally generated from known 10B values for simulated tumours with various volumes in a phantom. The 10B distributions in a tumour were also investigated and it was possible to distinguish the tumour with 10B from normal tissue without 10B. In addition, the 10B concentrations were estimated by calculations. A two-dimensional discrete ordinate transport code, DOT3.5, was employed for the calculations of the neutron fluence rate distributions in a phantom. The number of incidental gamma rays entering a germanium detector, which were produced in a tumour as a result of neutron reaction, were calculated by an analytical method. The results were in good agreement with the experiments. PMID:2038605

  5. Boron analysis for neutron capture therapy using particle-induced gamma-ray emission.

    PubMed

    Nakai, Kei; Yamamoto, Yohei; Okamoto, Emiko; Yamamoto, Tetsuya; Yoshida, Fumiyo; Matsumura, Akira; Yamada, Naoto; Kitamura, Akane; Koka, Masashi; Satoh, Takahiro

    2015-12-01

    The neutron source of BNCT is currently changing from reactor to accelerator, but peripheral facilities such as a dose-planning system and blood boron analysis have still not been established. To evaluate the potential application of particle-induced gamma-ray emission (PIGE) for boron measurement in clinical boron neutron capture therapy, boronophenylalanine dissolved within a cell culture medium was measured using PIGE. PIGE detected 18 μgB/mL f-BPA in the culture medium, and all measurements of any given sample were taken within 20 min. Two hours of f-BPA exposure was required to create a boron distribution image. However, even though boron remained in the cells, the boron on the cell membrane could not be distinguished from the boron in the cytoplasm. PMID:26242558

  6. Activation of macrophage peroxisome proliferator-activated receptor-gamma by diclofenac results in the induction of cyclooxygenase-2 protein and the synthesis of anti-inflammatory cytokines.

    PubMed

    Ayoub, Samir S; Botting, Regina M; Joshi, Amrish N; Seed, Michael P; Colville-Nash, Paul R

    2009-07-01

    Cyclooxygenase-2 (COX-2) is an inducible isoform of the COX family of enzymes central to the synthesis of pro-inflammatory prostaglandins. Induction of COX-2 is mediated by many endogenous and exogenous molecules that include pro-inflammatory cytokines and bacterial lipopolysaccharide (LPS). It has been demonstrated that COX-2 can also be induced by diclofenac in cultured J774.2 macrophages. This induction was delayed compared to COX-2 induced by LPS and paracetamol selectively inhibited activity of this protein. The aim of the present study was to determine the transcription factor involved in the production of COX-2 after treatment of J774.2 cells with 500 microM diclofenac. Pre-treatment of cells with the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) antagonists GW9662 (0.1-1 microM) or biphenol A Diglycidyl Ether (100-200 microM) resulted in reduction of the induction of COX-2 by diclofenac, but not by LPS. Induction of COX-2 by the PPAR-gamma agonist 15deoxyDelta(12,14)prostaglandin J(2) was also reduced when the cells were pre-treated with the PPAR-gamma antagonists BADGE or GW9662. On the other hand, pre-treatment of cells with the nuclear factor-kappa-B (NF-kappaB) Super-repressor IkappaBalpha (150-600 nM) reduced the induction of COX-2 by LPS, but not by diclofenac. We, therefore, have identified that PPAR-gamma activation is a requirement for COX-2 induction after diclofenac stimulation of J774.2 cells. These results along with the finding that treatment of J774.2 macrophages with diclofenac resulted in the release of the anti-inflammatory cytokines, interleukin-10 and transforming growth factor-beta suggest that the diclofenac-induced COX-2 protein may possess anti-inflammatory actions. PMID:19219624

  7. Quality analysis of in vivo near-infrared fluorescence and conventional gamma images acquired using a dual-labeled tumor-targeting probe.

    PubMed

    Houston, Jessica P; Ke, Shi; Wang, Wei; Li, Chun; Sevick-Muraca, Eva M

    2005-01-01

    The cyclic peptide, cyclopentapeptide cyclo(lys-Arg-Gly-Asp-phe) (c(KRGDf)), which is known to target alpha(v)beta3 integrin, is dual-labeled with a radiotracer, (111)indium, for gamma scintigraphy as well as with a near-infrared dye, IRDye800, for continuous-wave (cw) imaging of alpha(v)beta3 positive human M21 melanoma in xenografts. Twenty-four hours after administration of the dual-labeled peptide at a dose equivalent to 90 microCi of (111)In and 5 nmol of near-infrared (NIR) dye, whole-body gamma scintigraphy and cw imaging was conducted. Image acquisition time was 15 min for the gamma scintigraphy images and 800 ms for the optical images acquired using an NIR sensitive intensified charge-coupled device. The results show that while the target-to-background ratio (TBR) of nuclear and optical imaging were similar for surface regions of interest and consistent with the origin of gamma and NIR radiation from a common targeted peptide, the signal-to-noise ratio (SNR) was significantly higher for optical than nuclear imaging. Furthermore, an analysis of SNR versus contrast showed greater sensitivity of optical over nuclear imaging for the subcutaneous tumor targets. While tomographic reconstructions are necessary to probe TBR, SNR, and contrast for interior tissues, this work demonstrates for the first time the direct comparison of molecular optical and planar nuclear imaging for surface and subsurface cancers. PMID:16292970

  8. Analysis of New Orion Gamma Ray Data and Monte Carlo Simulations of BATSE Gamma Ray Bursts. Part 1

    NASA Technical Reports Server (NTRS)

    Lingenfelter, Richard E.

    1998-01-01

    These studies were stimulated by the reported COMPTEL detection of nuclear gamma ray line emission from the Orion star formation region. Although the observation have very recently been retracted, the detailed analyses that we carried out clearly showed that the low energy cosmic rays that would have been required to explain the reported fluxes were exceedingly restrictive and thus highly improbable. Moreover, these studies proved to be the trigger for very productive new work. In particular, they led us into carefully re-examining the problem of the origin of the light elements, Li, Be and B, where we showed that the light elements could, in fact, be produced primarily by Galactic cosmic rays and did not require an unobserved low energy cosmic ray source , as had been suggested. We further showed that the observed abundances of Be and B in old halo stars contradicted the common belief that the Galactic cosmic rays were accelerated out of the well mixed interstellar medium, and required instead that they be accelerated out of freshly synthesized matter from supernovae. This work, in turn, led us to propose a new origin of Galactic cosmic rays from the refractory grains in supernova enriched cores of superbubbles.

  9. First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10.

    PubMed

    Yoshikawa, M; Yasuhara, R; Nagasu, K; Shimamura, Y; Shima, Y; Kohagura, J; Sakamoto, M; Nakashima, Y; Imai, T; Ichimura, M; Yamada, I; Funaba, H; Kawahata, K; Minami, T

    2014-11-01

    A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system. PMID:25430214

  10. 81.114- University Reactor Infrastructure and Education Support / Prompt Gamma-ray Activation Analysis of Lithioum Ion Battery Cathodes

    SciTech Connect

    Manthiram, Arumugam; Landsberger, S.

    2006-11-11

    This project focuses on the use of the Prompt Gamma-ray Activation Analysis (PGAA) technique available at the Nuclear Engineering Teaching Laboratory of the University of Texas at Austin to precisely determine the hydrogen (proton) contents in layered oxide cathode samples obtained by chemical lithium extraction in order to obtain a better understanding of the factors limiting the practical capacities and overall performance of lithium ion battery cathodes. The project takes careful precautionary experimental measures to avoid proton contamination both from solvents used in chemical delithiation and from ambient moisture. The results obtained from PGAA are complemented by the data obtained from other techniques such as thermogravimetric analysis, redox titration, atomic absorption spectroscopy, X-ray diffraction, and mass spectroscopic analysis of the evolved gas on heating. The research results broaden our understanding of the structure-property-performance relationships of lithium ion battery cathodes and could aid the design and development of new better performing lithium ion batteries for consumer (portable and electric vehicles), military, and space applications.

  11. Lunar surface radioactivity - Preliminary results of the Apollo 15 and Apollo 16 gamma-ray spectrometer experiments.

    NASA Technical Reports Server (NTRS)

    Metzger, A. E.; Trombka, J. I.; Peterson, L. E.; Reedy, R. C.; Arnold, J. R.

    1973-01-01

    Gamma-ray spectrometers on the Apollo 15 and Apollo 16 missions have been used to map the moon's radioactivity over 20 percent of its surface. The highest levels of natural radioactivity are found in Mare Imbrium and Oceanus Procellarum with contrastingly lower enhancements in the eastern maria. The ratio of potassium to uranium is higher on the far side than on the near side, although it is everywhere lower than commonly found on the earth.

  12. POST-PERIASTRON GAMMA-RAY FLARE FROM PSR B1259-63/LS 2883 AS A RESULT OF COMPTONIZATION OF THE COLD PULSAR WIND

    SciTech Connect

    Khangulyan, Dmitry; Bogovalov, Sergey V.; Ribo, Marc E-mail: felix.aharonian@dias.ie E-mail: mribo@am.ub.es

    2012-06-10

    We argue that the bright flare of the binary pulsar PSR B1259-63/LS2883 detected by the Fermi Large Area Telescope is due to the inverse Compton scattering of the unshocked electron-positron pulsar wind with a Lorentz factor {Gamma}{sub 0} Almost-Equal-To 10{sup 4}. The combination of two effects both linked to the circumstellar disk (CD) is a key element in the proposed model. The first effect is related to the impact of the surrounding medium on the termination of the pulsar wind. Inside the disk, the 'early' termination of the wind results in suppression of its gamma-ray luminosity. When the pulsar escapes the disk, the conditions for termination of the wind undergo significant changes. This would lead to a dramatic increase of the pulsar wind zone, and thus to the proportional increase of the gamma-ray flux. On the other hand, if the parts of the CD disturbed by the pulsar can supply infrared photons of density high enough for efficient Comptonization of the wind, almost the entire kinetic energy of the pulsar wind would be converted to radiation, thus the gamma-ray luminosity of the wind could approach the level of the pulsar's spin-down luminosity as reported by the Fermi Collaboration.

  13. Very-long-baseline radio interferometry (VLBI) observations of gamma-ray blazars: results from millimeter-VLBI observations.

    PubMed Central

    Krichbaum, T P; Britzen, S; Standke, K J; Witzel, A; Schalinski, C J; Zensus, J A

    1995-01-01

    VLBI observations of the extremely gamma-bright blazar PKS 0528+134 at 8, 22, 43, and 86 GHz reveal a strongly bent one-sided-core jet structure with at least three moving and two apparently stationary jet components. At the highest observing frequencies the brightest and most compact jet component (the VLBI core) is unresolved with an upper limit to its size of approximately 50 microarcsec corresponding to approximately 0.2 parsec [H0 = 100 km.s-1.Mpc-1 (megaparsec-1), q0 = 0.5, where H0 is Hubble constant and q0 is the deceleration parameter]. Two 86-GHz VLBI observations performed in 1993.3 and 1994.0 reveal a new jet component emerging with superluminal speed from the core. Linear back-extrapolation of its motion yields strong evidence that the ejection of this component is related to an outburst in the millimeter regime and a preceding intense flare of the gamma-flux density observed in early 1993. This and the radio/optical "light curves" and VLBI data for two other sources (S5 0836+710 and 3C 454.3) suggest that the observed gamma-radiation might be Doppler-boosted and perhaps is closely related to the physical processes acting near the "base" of the highly relativistic jets observed in quasars. PMID:11607602

  14. Very-long-baseline radio interferometry (VLBI) observations of gamma-ray blazars: results from millimeter-VLBI observations.

    PubMed

    Krichbaum, T P; Britzen, S; Standke, K J; Witzel, A; Schalinski, C J; Zensus, J A

    1995-12-01

    VLBI observations of the extremely gamma-bright blazar PKS 0528+134 at 8, 22, 43, and 86 GHz reveal a strongly bent one-sided-core jet structure with at least three moving and two apparently stationary jet components. At the highest observing frequencies the brightest and most compact jet component (the VLBI core) is unresolved with an upper limit to its size of approximately 50 microarcsec corresponding to approximately 0.2 parsec [H0 = 100 km.s-1.Mpc-1 (megaparsec-1), q0 = 0.5, where H0 is Hubble constant and q0 is the deceleration parameter]. Two 86-GHz VLBI observations performed in 1993.3 and 1994.0 reveal a new jet component emerging with superluminal speed from the core. Linear back-extrapolation of its motion yields strong evidence that the ejection of this component is related to an outburst in the millimeter regime and a preceding intense flare of the gamma-flux density observed in early 1993. This and the radio/optical "light curves" and VLBI data for two other sources (S5 0836+710 and 3C 454.3) suggest that the observed gamma-radiation might be Doppler-boosted and perhaps is closely related to the physical processes acting near the "base" of the highly relativistic jets observed in quasars. PMID:11607602

  15. Determination of the optimum-size californium-252 neutron source for borehole capture gamma-ray analysis

    USGS Publications Warehouse

    Senftle, F.E.; Macy, R.J.; Mikesell, J.L.

    1979-01-01

    The fast- and thermal-neutron fluence rates from a 3.7 ??g 252Cf neutron source in a simulated borehole have been measured as a function of the source-to-detector distance using air, water, coal, iron ore-concrete mix, and dry sand as borehole media. Gamma-ray intensity measurements were made for specific spectral lines at low and high energies for the same range of source-to-detector distances in the iron ore-concrete mix and in coal. Integral gamma-ray counts across the entire spectrum were also made at each source-to-detector distance. From these data, the specific neutron-damage rate, and the critical count-rate criteria, we show that in an iron ore-concrete mix (low hydrogen concentration), 252Cf neutron sources of 2-40 ??g are suitable. The source size required for optimum gamma-ray sensitivity depends on the energy of the gamma ray being measured. In a hydrogeneous medium such as coal, similar measurements were made. The results show that sources from 2 to 20 ??g are suitable to obtain the highest gamma-ray sensitivity, again depending on the energy of the gamma ray being measured. In a hydrogeneous medium, significant improvement in sensitivity can be achieved by using faster electronics; in iron ore, it cannot. ?? 1979 North-Holland Publishing Co.

  16. 46 CFR 164.007-7 - Analysis of results.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Analysis of results. 164.007-7 Section 164.007-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Structural Insulations § 164.007-7 Analysis of results. (a) When only...

  17. 46 CFR 164.007-7 - Analysis of results.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Analysis of results. 164.007-7 Section 164.007-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Structural Insulations § 164.007-7 Analysis of results. (a) When only...

  18. 46 CFR 164.007-7 - Analysis of results.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Analysis of results. 164.007-7 Section 164.007-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Structural Insulations § 164.007-7 Analysis of results. (a) When only...

  19. 46 CFR 164.007-7 - Analysis of results.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Analysis of results. 164.007-7 Section 164.007-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Structural Insulations § 164.007-7 Analysis of results. (a) When only...

  20. Gamma-ray pulse height spectrum analysis on systems with multiple Ge detectors using a spectrum summing

    SciTech Connect

    Killian, E.W.

    1997-05-01

    A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radio nuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radionuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogenous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in each individual spectrum are poor. The spectrum summing technique adds the spectra collected by each detector into a single spectrum which has better counting statistics than each individual spectrum. A normal spectral analysis program can then be used to analyze the sum spectrum to obtain radio nuclide values which have smaller errors and do not have to be further manipulated to obtain results for the total waste container.

  1. Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

    NASA Astrophysics Data System (ADS)

    Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

    2013-04-01

    The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity

  2. Lunar elemental analysis obtained from the Apollo gamma-ray and X-ray remote sensing experiment

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Arnold, J. R.; Adler, I.; Metzger, A. E.; Reedy, R. C.

    1974-01-01

    Gamma ray and X-ray spectrometers carried in the service module of the Apollo 15 and 16 spacecraft were employed for compositional mapping of the lunar surface. The measurements involved the observation of the intensity and characteristics energy distribution of gamma rays and X-rays emitted from the lunar surface. A large scale compositional map of over 10 percent of the lunar surface was obtained from an analysis of the observed spectra. The objective of the X-ray experiment was to measure the K spectral lines from Mg, Al, and Si. Spectra were obtained and the data were reduced to Al/Si and Mg/Si intensity ratios and ultimately to chemical ratios. The objective of the gamma-ray experiment was to measure the natural and cosmic ray induced activity emission spectrum. At this time, the elemental abundances for Th, U, K, Fe, Ti, Si, and O have been determined over a number of major lunar regions.

  3. Portable microcomputer for the analysis of plutonium gamma-ray spectra. Volume II. Software description and listings. [IAEAPU

    SciTech Connect

    Ruhter, W.D.

    1984-05-01

    A portable microcomputer has been developed and programmed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra. The unit includes a 16-bit LSI-11/2 microprocessor, 32-K words of memory, a 20-character display for user prompting, a numeric keyboard for user responses, and a 20-character thermal printer for hard-copy output of results. The unit weights 11 kg and has dimensions of 33.5 x 30.5 x 23.0 cm. This compactness allows the unit to be stored under an airline seat. Only the positions of the 148-keV /sup 241/Pu and 208-keV /sup 237/U peaks are required for spectral analysis that gives plutonium isotopic ratios and weight percent abundances. Volume I of this report provides a detailed description of the data analysis methodology, operation instructions, hardware, and maintenance and troubleshooting. Volume II describes the software and provides software listings.

  4. Fermi/Gamma-ray Burst Monitor Analysis of SGR J1550-5418 Bursts During an Extreme Outburst in January 2009

    NASA Astrophysics Data System (ADS)

    Van Der Horst, Alexander Jonathan; Kouveliotou, C.; Kaneko, Y.; Gogus, E.; Gorgone, N.; GBM Magnetar Team

    2011-05-01

    In 2008 October, the Soft Gamma Repeater (SGR) J1550-5418 entered a burst active period that lasted one week. On 2009 January 22, the source entered a second, extremely active period, which lasted for one month, and was followed by a third, small episode in 2009 March. The highest number of bursts from the SGR ( 450) was observed on January 22 with the Fermi/Gamma-ray Burst Monitor (GBM). The combination of the unique GBM temporal and spectral capabilities has enabled us to study spectra of most of these SGR bursts in great detail. We present here the results of our time integrated spectral and temporal analysis of all the bursts observed with GBM during the source's active period in January 2009. Further, we compare the properties of these bursts with bursts observed from other SGR sources during extreme activations.

  5. PSR J0007+7303 in the CTA1I Supenova Remnant: New Gamma-Ray Results from Two Years of Fermi Large Area Telescope Observations

    NASA Technical Reports Server (NTRS)

    Abdo, A.; Wood, K.; DeCesar, M.; Gargano, F.; Giordano, F.; Ray, P. S.; Parent, D.; Harding, A.; Coleman, M.; Wood, D. L.; Wolff, M.

    2012-01-01

    One of the main results of the Fermi Gamma-Ray Space Telescope is the discovery of -ray selected pulsars. The high magnetic field pulsar, PSR J0007+7303 in CTA1, was the first ever to be discovered through its -ray pulsations. Based on analysis of two years of Large Area Telescope (LAT) survey data, we report on the discovery of -ray emission in the off-pulse phase interval at the 6 level. The emission appears to be extended at the 2 level with a disk of extension 0.6. level. The flux from this emission in the energy range E 100 MeV is F 100 = (1.73 0.40stat 0.18sys) 108photonscm2 s1 and is best fitted by a power law with a photon index of = 2.54 0.14stat 0.05sys. The pulsed -ray flux in the same energy range is F 100 = (3.95 0.07stat 0.30sys) 107photonscm2 s1 and is best fitted by an exponentially cutoff power-law spectrum with a photon index of = 1.41 0.23stat 0.03sys and a cutoff energy Ec = 4.04 0.20stat 0.67sysGeV. We find no flux variability either at the 2009 May glitch or in the long-term behavior. We model the -ray light curve with two high-altitude emission models, the outer gap and slot gap, and find that the preferred model depends strongly on the assumed origin of the off-pulse emission. Both models favor a large angle between the magnetic axis and observer line of sight, consistent with the nondetection of radio emission being a geometrical effect. Finally, we discuss how the LAT results bear on the understanding of the cooling of this neutron star.

  6. Whole-Genome Sequencing in Microbial Forensic Analysis of Gamma-Irradiated Microbial Materials

    PubMed Central

    Broomall, Stacey M.; Ait Ichou, Mohamed; Krepps, Michael D.; Johnsky, Lauren A.; Karavis, Mark A.; Hubbard, Kyle S.; Insalaco, Joseph M.; Betters, Janet L.; Redmond, Brady W.; Rivers, Bryan A.; Liem, Alvin T.; Hill, Jessica M.; Fochler, Edward T.; Roth, Pierce A.; Rosenzweig, C. Nicole; Skowronski, Evan W.

    2015-01-01

    Effective microbial forensic analysis of materials used in a potential biological attack requires robust methods of morphological and genetic characterization of the attack materials in order to enable the attribution of the materials to potential sources and to exclude other potential sources. The genetic homogeneity and potential intersample variability of many of the category A to C bioterrorism agents offer a particular challenge to the generation of attributive signatures, potentially requiring whole-genome or proteomic approaches to be utilized. Currently, irradiation of mail is standard practice at several government facilities judged to be at particularly high risk. Thus, initial forensic signatures would need to be recovered from inactivated (nonviable) material. In the study described in this report, we determined the effects of high-dose gamma irradiation on forensic markers of bacterial biothreat agent surrogate organisms with a particular emphasis on the suitability of genomic DNA (gDNA) recovered from such sources as a template for whole-genome analysis. While irradiation of spores and vegetative cells affected the retention of Gram and spore stains and sheared gDNA into small fragments, we found that irradiated material could be utilized to generate accurate whole-genome sequence data on the Illumina and Roche 454 sequencing platforms. PMID:26567301

  7. Experimental and vector analysis on gamma type Stirling engine with hot power cylinder

    SciTech Connect

    Isshiki, Naotsugu; Tsukahara, Shigeji; Ohtomo, Michihiro

    1995-12-31

    In 1993, the superiority of hot end connected power cylinder gamma type Stirling engine (HEC) compared to the conventional cold end connected power cylinder engine (CEC) was reported by Prof. J.Kentfield of the University of Calgary. It is a great thing that he introduced the HEC engine, and it reminded the authors that in 1980, they built and experimented with a three cylinder 3kW Stirling engine SRI-1, in which two cylinders are positively heated by gas, that is called HCH (Hot, Cold and Hot) engine as shown in a figure, and having similarity to the above HEC. The authors have developed a quite simple and understandable approximate harmonic vector analysis method for Stirling machines. By this, Kentfield`s HEC engine and their HCH engine are expressed by the same figure as shown in the paper. The similarity and superiority of HEC and HCH compared to CEC and CHC are easily shown by the vector analysis method with physical reason.

  8. Whole-Genome Sequencing in Microbial Forensic Analysis of Gamma-Irradiated Microbial Materials.

    PubMed

    Broomall, Stacey M; Ait Ichou, Mohamed; Krepps, Michael D; Johnsky, Lauren A; Karavis, Mark A; Hubbard, Kyle S; Insalaco, Joseph M; Betters, Janet L; Redmond, Brady W; Rivers, Bryan A; Liem, Alvin T; Hill, Jessica M; Fochler, Edward T; Roth, Pierce A; Rosenzweig, C Nicole; Skowronski, Evan W; Gibbons, Henry S

    2016-01-01

    Effective microbial forensic analysis of materials used in a potential biological attack requires robust methods of morphological and genetic characterization of the attack materials in order to enable the attribution of the materials to potential sources and to exclude other potential sources. The genetic homogeneity and potential intersample variability of many of the category A to C bioterrorism agents offer a particular challenge to the generation of attributive signatures, potentially requiring whole-genome or proteomic approaches to be utilized. Currently, irradiation of mail is standard practice at several government facilities judged to be at particularly high risk. Thus, initial forensic signatures would need to be recovered from inactivated (nonviable) material. In the study described in this report, we determined the effects of high-dose gamma irradiation on forensic markers of bacterial biothreat agent surrogate organisms with a particular emphasis on the suitability of genomic DNA (gDNA) recovered from such sources as a template for whole-genome analysis. While irradiation of spores and vegetative cells affected the retention of Gram and spore stains and sheared gDNA into small fragments, we found that irradiated material could be utilized to generate accurate whole-genome sequence data on the Illumina and Roche 454 sequencing platforms. PMID:26567301

  9. Abundance and distribution of radioelements in lunar terranes: Results of Chang'E-1 gamma ray spectrometer data

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Ling, Zongcheng; Li, Bo; Zhang, Jiang; Sun, Lingzhi; Liu, Jianzhong

    2016-02-01

    The gamma ray spectrometer (GRS) onboard Chang'E-1 has acquired valuable datasets recording the gamma ray intensities from radioelements (Potassium (K), Thorium (Th) and Uranium (U), etc.) on lunar surface. We extracted the elemental concentrations from the GRS data with spectral fitting techniques and mapped the global absolute abundance of radioelements in terms of the ground truths from lunar samples and meteorites. The obtained global concentration maps of these radioelements indicate heterogeneous distribution among three major lunar crustal terranes (i.e., Procellarum KREEP Terrane (PKT), Feldspathic Highlands Terrane (FHT), and South Pole Aitken Terrane (SPAT)) in relation with their origin and distinct geologic history. The majority of radioelements are restricted in PKT, approving the scenario of KREEP (Potassium (K), rare earth elements (REE), Phosphorus (P)) residua concentrating under the Procellarum region. Moreover, we found the consistency of distribution for radioelements and basalts, concluding that the subsequent volcanism might be associated with local concentrations of radioelements in western Oceanus Procellarum and northwestern South Pole Aitken Basin. The prominent and asymmetric radioactive signatures were confirmed in SPAT comparing to FHT dominated by low level radioactivity, while the magnitudes are much lower than that of PKT, indicating a primary geochemical heterogeneity for the Moon.

  10. Using Transaction Log Analysis To Improve OPAC Retrieval Results.

    ERIC Educational Resources Information Center

    Blecic, Deborah D.; Bangalore, Nirmala S.; Dorsch, Josephine L.; Henderson, Cynthia L.; Koenig, Melissa H.; Weller, Ann C.

    1998-01-01

    An OPAC transaction log analysis at the University of Illinois at Chicago revealed that users had trouble with basic search techniques. After the introductory screens were simplified, a second analysis showed improved search results, indicating that monitoring OPACs can lead to improved information retrieval when changes are made in response to…

  11. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    SciTech Connect

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-12-13

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.

  12. Analysis of gamma-ray spectra from foils activated in a range-thick lead target by 800-MeV protons. Final technical report

    SciTech Connect

    Laird, C.E.; Mullins, D.H.

    1995-06-12

    Approximately 400 gamma-ray spectra have been analyzed to obtain the types and quantities of radioisotopes produced when 800-MeV protons interact with a range-thick lead target. These spectra were obtained from the radioactive decay of product isotopes in lead disks placed at various depths and radial positions within the target. These spectra were analyzed with the computer code HYPERMET and the photopeak areas were reduced to nuclei produced per incident proton per cubic centimeter of material. Product nuclei ranged from atomic mass 160 to mass 206 and over a range of half lives from a few minutes to several weeks. The results of this analysis have been outlined in this report and transmitted on computer disk to Los Alamos National Laboratory. The consistency of these analyses have been confirmed by a comparison of photopeak areas obtained at LANL with the computer code GAMANAL with those from HYPERMET for two gamma-ray spectra. Also, the nuclear production per proton per cm{sub 3} obtained from these two spectra analyzed both at LANL and at EKU have been found to agree to within the statistical accuracy of the peak-fitting programs. This analysis of these 400 gamma-ray spectra has determined the nuclear production per incident proton per cm{sub 3} at five regularly-spaced radial positions and depths up to 40 cm into a range-thick lead target.

  13. 46 CFR 164.007-7 - Analysis of results.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL MATERIALS Structural Insulations § 164.007-7 Analysis of results. (a) When only one... to correction for inaccurate furnace control in accordance with § 164.007-4(d)(4)....

  14. DOE 2009 Geothermal Risk Analysis: Methodology and Results (Presentation)

    SciTech Connect

    Young, K. R.; Augustine, C.; Anderson, A.

    2010-02-01

    This presentation summarizes the methodology and results for a probabilistic risk analysis of research, development, and demonstration work-primarily for enhanced geothermal systems (EGS)-sponsored by the U.S. Department of Energy Geothermal Technologies Program.

  15. An analysis of a spreader bar crane mounted gamma-ray radiation detection system

    NASA Astrophysics Data System (ADS)

    Grypp, Matthew David

    Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192 Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 +/- 0.4 microcuries (muCi), 19.3 +/- 1.1 muCi, 11.7 +/- 0.6 muCi, 3.5 +/- 0.3 kilograms (kg), and 30.6 +/- 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.

  16. Catalytic oxidation of 2-Propanol over (Cr,Mn,Fe)-Pt/gamma-Al2O3 bimetallic catalysts and modeling of experimental results by artificial neural networks.

    PubMed

    Niaei, A; Salari, D; Aghazadeh, F; Caylak, N; Sepehrianazar, A

    2010-01-01

    The catalytic activity of transition metals (Cr,Mn,Fe) supported on the Pt/gamma -Al(2)O(3) industrial catalyst was investigated to bring about the complete oxidation of 2-Propanol. Catalytic studies were carried out under atmospheric pressure in a fixed bed reactor. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and ICP-AES techniques were used to characterize a series of catalysts. Results showed that the Pt-Mn/gamma -Al(2)O(3) (3.88 wt.%Mn) at calcination temperature of 300 degrees C was the most promising catalyst based on activity, which might be contributed to the quantity of manganese loading, the favorable synergetic effects between Pt and Mn and the well-dispersed bimetallic phase. An artificial neural networks (ANN) model was developed to predict the performance of catalytic oxidation process over Pt-Mn/gamma -Al(2)O(3) bimetallic catalyst based on experimental data. For this purpose the Levenberg-Marquardt (LM) learning algorithm was employed to train the model by using laboratory experimental data. A comparison between the predicted results of the designed ANN model and experimental data was also conducted. The developed model can describe the catalytic oxidation over bimetallic catalysts under different conditions. PMID:20390890

  17. Gamma Knife

    MedlinePlus

    ... results are sent to the Gamma Knife®'s planning computer system. Together, physicians ( radiation oncologists and neurosurgeons) and medical physicists delineate targets and normal anatomical structures. They use a planning computer program to determine the exact spatial relationship between ...

  18. 2015 Long-Term Hydrologic Monitoring Program Sampling and Analysis Results Report for Project Rulison, Co

    SciTech Connect

    Findlay, Rick; Kautsky, Mark

    2015-12-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 20–22 and 27, 2015. Several of the land owners were not available to allow access to their respective properties, which created the need for several sample collection trips. This report documents the analytical results of the Rulison monitoring event and includes the trip report and the data validation package (Appendix A). The groundwater and surface water monitoring were shipped to the GEL Group Inc. laboratories for analysis. All requested analyses were successfully completed. Samples were analyzed for gamma-emitting radionuclides by high- resolution gamma spectrometry. Tritium was analyzed using two methods, the conventional tritium method, which has a detection limit on the order of 400 picocuries per liter (pCi/L), and the enriched method (for selected samples), which has a detection limit on the order of 3 pCi/L.

  19. Transgenic Overexpression of Tcfap2c/AP-2gamma Results in Liver Failure and Intestinal Dysplasia

    PubMed Central

    Woynecki, Tatiana; Egert, Angela; Becker, Astrid; Huss, Sebastian; Stabenow, Dirk; Zimmer, Andreas; Knolle, Percy; Tolba, René; Fischer, Hans-Peter; Schorle, Hubert

    2011-01-01

    Background The transcription factor Tcfap2c has been demonstrated to be essential for various processes during mammalian development. It has been found to be upregulated in various undifferentiated tumors and is implicated with poor prognosis. Tcfap2c is reported to impinge on cellular proliferation, differentiation and apoptosis. However, the physiological consequences of Tcfap2c-expression remain largely unknown. Methodology/Principal Findings Therefore we established a gain of function model to analyze the role of Tcfap2c in development and disease. Induction of the transgene led to robust expression in all tissues (except brain and testis) and lead to rapid mortality within 3–7 days. In the liver cellular proliferation and apoptosis was detected. Accumulation of microvesicular lipid droplets and breakdown of major hepatic metabolism pathways resulted in steatosis. Serum analysis showed a dramatic increase of enzymes indicative for hepatic failure. After induction of Tcfap2c we identified a set of 447 common genes, which are deregulated in both liver and primary hepatocyte culture. Further analysis showed a prominent repression of the cytochrome p450 system, PPARA, Lipin1 and Lipin2. These data indicate that in the liver Tcfap2c represses pathways, which are responsible for fatty acid metabolism. In the intestine, Tcfap2c expression resulted in expansion of Sox9 positive and proliferative active epithelial progenitor cells resulting in dysplastic growth of mucosal crypt cells and loss of differentiated mucosa. Conclusions The transgenic mice show that ectopic expression of Tcfap2c is not tolerated. Due to the phenotype observed, iTcfap2c-mice represent a model system to study liver failure. In intestine, Tcfap2c induced cellular hyperplasia and suppressed terminal differentiation indicating that Tcfap2c serves as a repressor of differentiation and inducer of proliferation. This might be achieved by the Tcfap2c mediated activation of Sox9 known to be expressed

  20. Targeted disruption of retinoic acid receptor alpha (RAR alpha) and RAR gamma results in receptor-specific alterations in retinoic acid-mediated differentiation and retinoic acid metabolism.

    PubMed Central

    Boylan, J F; Lufkin, T; Achkar, C C; Taneja, R; Chambon, P; Gudas, L J

    1995-01-01

    F9 embryonic teratocarcinoma stem cells differentiate into an epithelial cell type called extraembryonic endoderm when treated with retinoic acid (RA), a derivative of retinol (vitamin A). This differentiation is presumably mediated through the actions of retinoid receptors, the RARs and RXRs. To delineate the functions of each of the different retinoid receptors in this model system, we have generated F9 cell lines in which both copies of either the RAR alpha gene or the RAR gamma gene are disrupted by homologous recombination. The absence of RAR alpha is associated with a reduction in the RA-induced expression of both the CRABP-II and Hoxb-1 (formerly 2.9) genes. The absence of RAR gamma is associated with a loss of the RA-inducible expression of the Hoxa-1 (formerly Hox-1.6), Hoxa-3 (formerly Hox-1.5), laminin B1, collagen IV (alpha 1), GATA-4, and BMP-2 genes. Furthermore, the loss of RAR gamma is associated with a reduction in the metabolism of all-trans-RA to more polar derivatives, while the loss of RAR alpha is associated with an increase in metabolism of RA relative to wild-type F9 cells. Thus, each of these RARs exhibits some specificity with respect to the regulation of differentiation-specific gene expression. These results provide an explanation for the expression of multiple RAR types within one cell type and suggest that each RAR has specific functions. PMID:7823950

  1. A Quantitative Proteomic Analysis of Urine from Gamma-Irradiated Non-Human Primates

    PubMed Central

    Byrum, Stephanie D; Burdine, Marie S; Orr, Lisa; Moreland, Linley; Mackintosh, Samuel G; Authier, Simon; Pouliot, Mylene; Hauer-Jensen, Martin; Tackett, Alan J

    2016-01-01

    The molecular effects of total body gamma-irradiation exposure are of critical importance as large populations of people could be exposed either by terrorists, nuclear blast, or medical therapy. In this study, we aimed to identify changes in the urine proteome using a non-human primate model system, Rhesus macaque, in order to characterize effects of acute radiation syndrome following whole body irradiation (Co-60) at 6.7 Gy and 7.4 Gy with a twelve day observation period. The urine proteome is potentially a valuable and non-invasive diagnostic for radiation exposure. Using high-resolution mass spectrometry, we identified 2346 proteins in the urine proteome. We show proteins involved in disease, cell adhesion, and metabolic pathway were significantly changed upon exposure to differing levels and durations of radiation exposure. Cell damage increased at a faster rate at 7.4 Gy compared with 6.7 Gy exposures. We report sets of proteins that are putative biomarkers of time- and dose-dependent radiation exposure. The proteomic study presented here is a comprehensive analysis of the urine proteome following radiation exposure. PMID:26962295

  2. Molecular characterization and expression analysis of interferon-gamma in the large yellow croaker Larimichthys crocea.

    PubMed

    Chen, Ruan-Ni; Su, Yong-Quan; Wang, Jun; Liu, Min; Qiao, Ying; Mao, Yong; Ke, Qiao-Zhen; Han, Kun-Huang; Zheng, Wei-Qiang; Zhang, Jian-She; Wu, Chang-Wen

    2015-10-01

    The large yellow croaker Larimichthys crocea is an important mariculture fish species in China, and the bacterium Vibrio harveyi (V. harveyi) and the ciliate protozoan Cryptocaryon irritans (C. irritans) are the two major pathogens in its aquaculture sector. Interferon-gamma (IFN-γ) plays important roles in regulating both innate and cell mediated immune responses as an inflammatory cytokine. In this study, we obtained the nucleotide sequence of IFN-γ from the large yellow croaker (LcIFN-γ). The phylogenetic relationship tree of 18 available IFN-γ genes was constructed based on their sequences. Expression analyses in 10 various tissues were conducted after the croaker challenged with V. harveyi and C. irritans, respectively. Real time PCR analysis showed that the expression of LcIFN-γ was observed broadly in health individuals. After injected with V. harveyi, the 10 tissues had a higher expression of IFN-γ at the first day (1 d); only spleen, muscle, intestine, heart and skin had higher expressions after infected with C. irritans at 1 d. Major immune tissues (skin, gill, head kidney and spleen) and detoxification tissue (liver) were sampled at 0 h, 6 h, 1 d, 2 d, 3 d, 4 d, 5 d and 7 d to understand the expression trends of LcIFN-γ after challenged with C. irritans. The expressions of LcIFN-γ in skin and gill (the primary immune organs) showed a clear correlative relationship with the life cycle of C. irritans. PMID:26193669

  3. Thermal analysis for study of the gamma radiation effects in poly(vinylidene fluoride)

    NASA Astrophysics Data System (ADS)

    Medeiros, Adriana S.; Gual, Maritza R.; Pereira, Claubia; Faria, Luiz O.

    2015-11-01

    Poly(vinylidene fluoride) (PVDF) has attracted interest in the technology and industrial sectors, due to its mechanical and electrical properties, its resistance to weathering and its thermostability. It is well known that polymer properties change after irradiation. Thermal degradation studies after irradiation of the polymers play an important role in establishing the threshold temperature for breakdown and information about the molecular and crystalline structure. A systematic study of the effects of gamma irradiation on PVDF using DSC, TG, DTA, FTIR and XRD techniques has been conducted. The samples were irradiated with a Co-60 source at constant dose rate (12.0 kGy/h), with doses ranging from 100 kGy to 3000 kGy. The DSC data reveals a decrease in the melting temperature and melting latent heat for increasing doses. There is a remarkable decrease in the melting latent heat ranging from 46 J/kg (pristine sample) to 26 J/kg (3000 kGy). The data analysis suggests that the decrease observed in the onset decomposition temperature is due to the radio-induction of C=C bonds in the crosslinking process and that the increase of the residual amount is due to the radio-induction of C=O bonds, via chain scission.

  4. Analysis and recent advances in gamma heating measurements in MINERVE facility by using TLD and OSLD techniques

    SciTech Connect

    Amharrak, H.; Di Salvo, J.; Lyoussi, A.; Roche, A.; Masson-Fauchier, M.; Bosq, J. C.

    2011-07-01

    The objective of this study is to develop nuclear heating measurement methods in Zero Power experimental reactors. This paper presents the analysis of Thermo-Luminescent Detector (TLD) and Optically Stimulated Luminescent Detectors (OSLD) experiments in the UO{sub 2} core of the MINERVE research reactor at the CEA Cadarache. The experimental sources of uncertainties on the gamma dose have been reduced by improving the conditions, as well as the repeatability, of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account calculation of cavity correction factors, related to calibration and irradiation configurations, as well as neutron corrections calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. TLD and OSLD are positioned inside aluminum pillboxes. The comparison between calculated and measured integral gamma-ray absorbed doses using TLD, shows that calculation slightly overestimates the measurement with a C/E value equal to 1.05 {+-} 5.3 % (k = 2). By using OSLD, the calculation slightly underestimates the measurement with a C/E value equal to 0.96 {+-} 7.0% (k = 2. (authors)

  5. Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

    SciTech Connect

    Mitra,S.

    2008-11-17

    In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described.

  6. The gamma-ray telescope Gamma-1

    NASA Technical Reports Server (NTRS)

    Akimov, V. V.; Nesterov, V. E.; Rodin, V. G.; Kalinkin, L. F.; Balibanov, V. M.; Prilutsky, O. F.; Leikov, N. G.; Bielaoussov, A. S.; Dobrian, L. B.; Poluektov, V. P.

    1985-01-01

    French and Soviet specialists have designed and built the gamma-ray telescope GAMMA-1 to detect cosmic gamma rays above 50 MeV. The sensitive area of the detector is 1400 sq cm, energy resolution is 30% at 300 MeV, and angular resolution 1.2 deg at 300 MeV (and less than 20' arc when a coded aperture mask is used). Results on calibration of the qualification model and Monte-Carlo calculations are presented.

  7. The Northern Marshall Islands radiological survey: A quality control program for radiochemical and gamma spectroscopy analysis

    SciTech Connect

    Kehl, S.R.; Mount, M.E.; Robison, W.L.

    1995-09-01

    From 1979 to 1989, approximately 25,000 Post Northern Marshall Islands Radiological Survey (PNMIRS) samples were collected, and over 71,400 radiochemical and gamma spectroscopy analyses were performed to establish the concentration of {sup 90}Sr, {sup 137}Cs, {sup 241}Am, and plutonium isotopes in soil, vegetation, fish, and animals in the Northern Marshall Islands. While the Low Level Gamma Counting Facility (B379) in the Health and Ecological Assessment (HEA) division accounted for over 80% of all gamma spectroscopy analyses, approximately 4889 radiochemical and 5437 gamma spectroscopy analyses were performed on 4784 samples of soil, vegetation, terrestrial animal, and marine organisms by outside laboratories. Four laboratories were used by Lawrence Livermore National Laboratory (LLNL) to perform the radiochemical analyses: Thermo Analytical Norcal, Richmond, California (TMA); Nuclear Energy Services, North Carolina State University (NCSU); Laboratory of Radiation Ecology, University of Washington (LRE); and Health and Ecological Assessment (HEA) division, LLNL, Livermore, California. Additionally, LRE and NCSU were used to perform gamma spectroscopy analyses. The analytical precision and accuracy were monitored by including blind duplicates and natural matrix standards in each group of samples analyzed. On the basis of reported analytical values for duplicates and standards, 88% of the gamma and 87% of the radiochemical analyses in this survey were accepted. By laboratory, 93% of the radiochemical analyses by TMA; 88% of the gamma-ray spectrometry and 100% of the radiochemistry analyses by NCSU; 89% of the gamma spectroscopy and 87% of the radiochemistry analyses by LRE; and 90% of the radiochemistry analyses performed by HEA`s radiochemistry department were accepted.

  8. Analysis of historical gross gamma logging data from BY tank farm

    SciTech Connect

    MYERS, D.A.

    1999-10-13

    Gross gamma ray logs, recorded from January 1975 through mid-year 1994 as part of the Single-Shell Tank Farm Dry Well Surveillance Program, have been reanalyzed for the BY tank farm to locate the presence of mobile radionuclides in the subsurface. This report presents the BY tank farm gross gamma ray data in such a way as to assist others in their study of vadose zone mechanisms.

  9. Analysis of historical gross gamma logging data from TY tank farm

    SciTech Connect

    MYERS, D.A.

    1999-10-19

    Gross gamma ray logs, recorded from January 1975 through mid-year 1994 as part of the Single-Shell Tank Farm Dry Well Surveillance Program, have been reanalyzed for the TY tank farm to locate the presence of mobile radionuclides in the subsurface. This report presents the TY tank farm gross gamma ray data in such a way as to assist others in their study of vadose zone mechanism.

  10. Analysis of Chromosomal Aberrations after Low and High Dose Rate Gamma Irradiation in ATM or NBS Suppressed Human Fibroblast Cells

    NASA Technical Reports Server (NTRS)

    Hada, M.; Huff, J. L.; Patel, Z.; Pluth, J. M.; George, K. A.; Cucinotta, F. A.

    2009-01-01

    A detailed understanding of the biological effects of heavy nuclei is needed for space radiation protection and for cancer therapy. High-LET radiation produces more complex DNA lesions that may be non-repairable or that may require additional processing steps compared to endogenous DSBs, increasing the possibility of misrepair. Interplay between radiation sensitivity, dose, and radiation quality has not been studied extensively. Previously we studied chromosome aberrations induced by low- and high- LET radiation in several cell lines deficient in ATM (ataxia telangactasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. We found that the yields of both simple and complex chromosomal aberrations were significantly increased in the DSB repair defective cells compared to normal cells. The increased aberrations observed for the ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex aberrations, while the linear dose-response term was significantly higher in NBS cells only for simple exchanges. These results point to the importance of the functions of ATM and NBS in chromatin modifications that function to facilitate correct DSB repair and minimize aberration formation. To further understand the sensitivity differences that were observed in ATM and NBS deficient cells, in this study, chromosomal aberration analysis was performed in normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, or Mirin, an MRN complex inhibitor involved in activation of ATM. We are also testing siRNA knockdown of these proteins. Normal and ATM or NBS suppressed cells were irradiated with gamma-rays and chromosomes were collected with a premature chromosome

  11. Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

    NASA Astrophysics Data System (ADS)

    Nasrabadi, M. N.; Bakhshi, F.; Jalali, M.; Mohammadi, A.

    2011-12-01

    Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by 14N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A 252Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C3H6N6). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

  12. RDV Analysis and Mark 4/VLBA Comparison Results

    NASA Technical Reports Server (NTRS)

    Gordon, David

    2002-01-01

    The processing of the RDV sessions and problems encountered in their analysis axe briefly discussed. Results of a VLBA/Mark 4 correlator comparison are presented. Comparison of group delays in session RDV22 processed by two different correlating/fringing systems shows good agreement, with an RMS of approx. 12 psec. Group delay formal errors may be underestimated in the RDV processing.

  13. SIMS prototype system 3 test results: Engineering analysis

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The results obtained during testing of a closed hydronic drain down solar system designed for space and hot water heating is presented. Data analysis is included which documents the system performance and verifies the suitability of SIMS Prototype System 3 for field installation.

  14. Total-body calcium estimated by delayed gamma neutron activation analysis and dual-energy X-ray absorptiometry.

    PubMed

    Aloia, J F; Ma, R; Vaswani, A; Feuerman, M

    1999-01-01

    Total body calcium (TBCa) in 270 black and white women age 21-79 years was measured concurrently by delayed gamma neutron activation analysis (DGNA) and dual-energy X-ray absorptiometry (DXA). The mean value for TBCa calculated from DXA was 933 g compared with 730 g for DGNA. By regression, TBCa(DXA(g)) = 1.35 x TBCa(DGNA(g)) -54 (r = 0. 90, r(2) = 81.4%, SEE = 66.9 g). This remarkable difference of 203 g suggests that one or both these methods is not accurate. Adjustment of the regression of DXA versus DGNA for body mass index or trunk thickness explained 8.5-10% of the variability between methods. The unadjusted slope for the DXA values regressed against the DGNA values was 1.35, indicating significant discordance between the methods. There is greater agreement between the two DGNA facilities (Brookhaven National Laboratory and Baylor College of Medicine) and between the various DXA instruments. Either DGNA underestimates TBCa or DXA overestimates total-body bone mineral content. Resolution of these disparate results may possibly be achieved by concurrent measurement of whole human cadavers of different sizes with chemical determination of the calcium content of the ash. In the interim, cross-calibration equations between DGNA and standardized values for DXA for total-body bone mineral content may be used, which will permit reporting of consistent values for TBCa from the two technologies. PMID:10663353

  15. A benchmarked MCNP model of the in vivo detection of gadolinium by prompt gamma neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Gräfe, J. L.; McNeill, F. E.; Byun, S. H.; Chettle, D. R.; Noseworthy, M. D.

    2010-08-01

    Gadolinium (Gd)-based contrast agents are a valuable diagnostic aid for magnetic resonance imaging (MRI). The amount of free Gd deposited in tissues following contrast enhanced MRI is of toxicological concern. The McMaster University in vivo prompt gamma neutron activation analysis facility has been adapted for the detection of Gd in the kidney, liver, and the leg muscle. A simple model of the HPGe detector used for detection of the prompt γ-rays following Gd neutron capture has been created using Monte Carlo simulation. A separate simulation describing the neutron collimation and shielding apparatus has been modified to determine the neutron capture rate in the Gd phantoms. The MCNP simulation results have been confirmed by experimental measurement. The deviations between MCNP and the experiment were between 1% and 18%, with an average deviation of 3.8 ± 6.7%. The validated MCNP model is to be used to improve the Gd in vivo measurement sensitivity by determining the best neutron moderator/reflector arrangement.

  16. 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.

  17. Spectral analysis of paramagnetic centers induced in human tooth enamel by x-rays and gamma radiation

    NASA Astrophysics Data System (ADS)

    Kirillov, V. A.; Kuchuro, I. I.

    2010-03-01

    Based on study of spectral and relaxation characteristics, we have established that paramagnetic centers induced in tooth enamel by x-rays and gamma radiation are identical in nature. We show that for the same exposure dose, the intensity of the electron paramagnetic resonance (EPR) signal induced by x-radiation with effective energy 34 keV is about an order of magnitude higher than the amplitude of the signal induced by gamma radiation. We have identified a three-fold attenuation of the EPR signal along the path of the x-radiation from the buccal to the lingual side of a tooth, which is evidence that the individual had undergone diagnostic x-ray examination of the dentition or skull. We have shown that the x-ray exposure doses reconstructed from the EPR spectra are an order of magnitude higher than the applied doses, while the dose loads due to gamma radiation are equal to the applied doses. The data obtained indicate that for adequate reconstruction of individual absorbed doses from EPR spectra of tooth enamel in the population subjected to the combined effect of x-radiation and accidental external gamma radiation as a result of the disaster at the Chernobyl nuclear power plant, we need to take into account the contribution to the dose load from diagnostic x-rays in examination of the teeth, jaw, or skull.

  18. NATURAL CONVECTION IN PASSIVE SOLAR BUILDINGS: EXPERIMENTS, ANALYSIS AND RESULTS

    SciTech Connect

    Gadgil, A.; Bauman, F.; Kammerud, R.

    1981-04-01

    Computer programs have been developed to numerically simulate natural convection in two- and three-dimensional room geometries. The programs have been validated using published data from the literature, results from a full-scale experiment performed at the Massachusetts Institute of Technology, and results from a small-scale experiment performed at LBL. One of the computer programs has been used to study the influence of natural convection on the thermal performance of a single zone in a direct-gain passive solar building. It is found that the convective heat transfer coefficients between the air and the enclosure surfaces can be substantially different from the values assumed in the standard building energy analysis methods, and can exhibit significant variations across a given surface. This study implies that the building heating loads calculated by standard building energy analysis methods may have substantial errors as a result of their use of common assumptions regarding the convection processes which occur in an enclosure.

  19. Gamma-ray peak shapes from cadmium zinc telluride detectors

    SciTech Connect

    Namboodiri, M.N.; Lavietes, A.D.; McQuaid, J.H.

    1996-09-01

    We report the results of a study of the peak shapes in the gamma spectra measured using several 5 x 5 x 5 mm{sup 3} cadmium zinc telluride (CZT) detectors. A simple parameterization involving a Gaussian and an exponential low energy tail describes the peak shapes sell. We present the variation of the parameters with gamma energy. This type of information is very useful in the analysis of complex gamma spectra consisting of many peaks.

  20. Representation of analysis results involving aleatory and epistemic uncertainty.

    SciTech Connect

    Johnson, Jay Dean; Helton, Jon Craig; Oberkampf, William Louis; Sallaberry, Cedric J.

    2008-08-01

    Procedures are described for the representation of results in analyses that involve both aleatory uncertainty and epistemic uncertainty, with aleatory uncertainty deriving from an inherent randomness in the behavior of the system under study and epistemic uncertainty deriving from a lack of knowledge about the appropriate values to use for quantities that are assumed to have fixed but poorly known values in the context of a specific study. Aleatory uncertainty is usually represented with probability and leads to cumulative distribution functions (CDFs) or complementary cumulative distribution functions (CCDFs) for analysis results of interest. Several mathematical structures are available for the representation of epistemic uncertainty, including interval analysis, possibility theory, evidence theory and probability theory. In the presence of epistemic uncertainty, there is not a single CDF or CCDF for a given analysis result. Rather, there is a family of CDFs and a corresponding family of CCDFs that derive from epistemic uncertainty and have an uncertainty structure that derives from the particular uncertainty structure (i.e., interval analysis, possibility theory, evidence theory, probability theory) used to represent epistemic uncertainty. Graphical formats for the representation of epistemic uncertainty in families of CDFs and CCDFs are investigated and presented for the indicated characterizations of epistemic uncertainty.

  1. Uncertainty of calculation results in vehicle collision analysis.

    PubMed

    Wach, Wojciech; Unarski, Jan

    2007-04-11

    In the analysis of road accidents two types of calculation result uncertainty can be distinguished: modelling uncertainty and uncertainty in calculation results [R.M. Brach, M. Brach, Vehicle Accident Analysis & Reconstruction Methods, SAE International Publisher, Warrendale, 2005]. The problem becomes very important first of all when minor modifications of input parameters or application of different models of the phenomenon lead to a fundamentally different answer to the question posed by the court. The aim of the paper was to prove the necessity of including the problem of uncertainty in calculations related to vehicle collision mechanics and to justify the application of different error analysis methods recommendable in vehicle collision reconstruction. The data file from crash test No. 7 [H. Burg, M. Lindenmann, Unfallversuche, Verlag Information Ambs, Kippenheim, 1982] was used, the selection restricted to the range typical of average police records of collision place. Collision speeds were calculated using two methods: reconstruction and simulation. The analysis of uncertainty was carried out. Maximum and mean square uncertainty were calculated by means of total differential of relevant forms. Since the reconstruction resulted in very broad error intervals of uniform distribution, additional calculations were performed by the Monte Carlo method using algorithm described in [W. Wach, J. Unarski, Determination of vehicle velocities and collision location by means of Monte Carlo simulation method, Special Publication Accident Reconstruction SP-1999, SAE Paper No. 2006-01-0907, 2006]. PMID:16884874

  2. Recent results on parametric analysis of differential Omega error

    NASA Technical Reports Server (NTRS)

    Baxa, E. G., Jr.; Piserchia, P. V.

    1974-01-01

    Previous tests of the differential Omega concept and an analysis of the characteristics of VLF propagation make it possible to delineate various factors which might contribute to the variation of errors in phase measurements at an Omega receiver site. An experimental investigation is conducted to determine the effect of each of a number of parameters on differential Omega accuracy and to develop prediction equations. The differential Omega error form is considered and preliminary results are presented of the regression analysis used to study differential error.

  3. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus

    SciTech Connect

    Giacomelli, L.; Conroy, S.; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-15

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  4. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus

    NASA Astrophysics Data System (ADS)

    Giacomelli, L.; Conroy, S.; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-01

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  5. Proximal Gamma-Ray Spectroscopy to Predict Soil Properties Using Windows and Full-Spectrum Analysis Methods

    PubMed Central

    Mahmood, Hafiz Sultan; Hoogmoed, Willem B.; van Henten, Eldert J.

    2013-01-01

    Fine-scale spatial information on soil properties is needed to successfully implement precision agriculture. Proximal gamma-ray spectroscopy has recently emerged as a promising tool to collect fine-scale soil information. The objective of this study was to evaluate a proximal gamma-ray spectrometer to predict several soil properties using energy-windows and full-spectrum analysis methods in two differently managed sandy loam fields: conventional and organic. In the conventional field, both methods predicted clay, pH and total nitrogen with a good accuracy (R2 ≥ 0.56) in the top 0–15 cm soil depth, whereas in the organic field, only clay content was predicted with such accuracy. The highest prediction accuracy was found for total nitrogen (R2 = 0.75) in the conventional field in the energy-windows method. Predictions were better in the top 0–15 cm soil depths than in the 15–30 cm soil depths for individual and combined fields. This implies that gamma-ray spectroscopy can generally benefit soil characterisation for annual crops where the condition of the seedbed is important. Small differences in soil structure (conventional vs. organic) cannot be determined. As for the methodology, we conclude that the energy-windows method can establish relations between radionuclide data and soil properties as accurate as the full-spectrum analysis method. PMID:24287541

  6. Design, construction, and characterization of a facility for neutron capture gamma ray analysis of sulfur in coal using californium-252

    SciTech Connect

    Layfield, J.R.

    1980-03-01

    A study of neutron capture gamma ray analysis of sulfur in coal using californium-252 as a neutron source is reported. Both internal and external target geometries are investigated. The facility designed for and used in this study is described. The external target geometry is found to be inappropriate because of the low thermal neutron flux at the sample location, which must be outside the biological shielding. The internal target geometry is found to have a sufficient thermal neutron flux, but an excessive gamma ray background. A water filled plastic facility, rather than the paraffin filled steel one used in this study, is suggested as a means of increasing flexibility and decreasing the beackground in the internal target geometry.

  7. Analysis of vehicle fuel release resulting in waste tank fire

    SciTech Connect

    STEPHENS, L.S.

    2003-03-21

    This document reevaluates several aspects of the in-tank vehicle fuel fire/deflagration accident formally documented as an independent accident (representative accident [rep acc] 2). This reevaluation includes frequencies for the accidents and incorporates the behavior of gasoline and diesel fuel in more detail than previous analysis. This reevaluation uses data from RPP-13121, ''Historical Summary of Occurrences from the Tank Farm Safety Analysis Report'', Table B-1, ''Tank Farm Events, Off-Normal and Critiques,'' and B-2, ''Summary of Occurrences,'' and from the River Protection Project--Occurrence Reporting & Processing System (ORPS) reports as a basis for changing some of the conclusions formally reported in HNF-SD-WM-CN-037, ''Frequency Analysis of Vehicle Fuel Releases Resulting in Waste Tank Fire''. This calculation note will demonstrate that the in-tank vehicle fuel fire/deflagration accident event may be relocated to other, more bounding accidents.

  8. Bioelectrical impedance analysis for bovine milk: Preliminary results

    NASA Astrophysics Data System (ADS)

    Bertemes-Filho, P.; Valicheski, R.; Pereira, R. M.; Paterno, A. S.

    2010-04-01

    This work reports the investigation and analysis of bovine milk quality by using biological impedance measurements using electrical impedance spectroscopy (EIS). The samples were distinguished by a first chemical analysis using Fourier transform midinfrared spectroscopy (FTIR) and flow citometry. A set of milk samples (100ml each) obtained from 17 different cows in lactation with and without mastitis were analyzed with the proposed technique using EIS. The samples were adulterated by adding distilled water and hydrogen peroxide in a controlled manner. FTIR spectroscopy and flow cytometry were performed, and impedance measurements were made in a frequency range from 500Hz up to 1MHz with an implemented EIS system. The system's phase shift was compensated by measuring saline solutions. It was possible to show that the results obtained with the Bioelectrical Impedance Analysis (BIA) technique may detect changes in the milk caused by mastitis and the presence of water and hydrogen peroxide in the bovine milk.

  9. THE FERMI ALL-SKY VARIABILITY ANALYSIS: A LIST OF FLARING GAMMA-RAY SOURCES AND THE SEARCH FOR TRANSIENTS IN OUR GALAXY

    SciTech Connect

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bottacini, E.; Antolini, E.; Bonamente, E.; Baldini, L.; Ballet, J.; Bastieri, D.; Bellazzini, R.; Bregeon, J.; Bouvier, A.; Brandt, T. J.; Brigida, M.; Bruel, P. E-mail: allafort@stanford.edu [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS and others

    2013-07-01

    In this paper, we present the Fermi All-sky Variability Analysis (FAVA), a tool to systematically study the variability of the gamma-ray sky measured by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. For each direction on the sky, FAVA compares the number of gamma-rays observed in a given time window to the number of gamma-rays expected for the average emission detected from that direction. This method is used in weekly time intervals to derive a list of 215 flaring gamma-ray sources. We proceed to discuss the 27 sources found at Galactic latitudes smaller than 10 Degree-Sign and show that, despite their low latitudes, most of them are likely of extragalactic origin.

  10. The Fermi All-Sky Variability Analysis: A List of Flaring Gamma-Ray Sources and the Search for Transients in our Galaxy

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Brandt, T. J.; Ferrara, E. C.; Guiriec, S.; Harding, A. K.; Hays, E.; Hewitt, J.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Scargle, J. D; Thompson, D. J.; Troja, E.

    2013-01-01

    In this paper, we present the Fermi All-sky Variability Analysis (FAVA), a tool to systematically study the variability of the gamma-ray sky measured by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope.For each direction on the sky, FAVA compares the number of gamma-rays observed in a given time window to the number of gamma-rays expected for the average emission detected from that direction. This method is used in weekly time intervals to derive a list of 215 flaring gamma-ray sources. We proceed to discuss the 27 sources found at Galactic latitudes smaller than 10 and show that, despite their low latitudes, most of them are likely of extragalactic origin.

  11. Thermal analysis evaluation of mechanical properties changes promoted by gamma radiation on surgical polymeric textiles

    NASA Astrophysics Data System (ADS)

    Ferreira, L. M.; Casimiro, M. H.; Oliveira, C.; Cabeço Silva, M. E.; Marques Abreu, M. J.; Coelho, A.

    2002-05-01

    The large number of surgical operations with post-operative infection problems and the appearing of new infectious diseases, contribute to the development of new materials in order to answer the needs of health care services. This development must take into account the modifications promoted by sterilisation methods in materials, namely by gamma radiation. The differential scanning calorimetry (DSC) and thermogravimetry (TGA) techniques show that a nonwoven and a laminate textiles maintain a good molecular cohesion, do not showing high levels of degradation, for gamma radiation dose values lower than 100 kGy in nonwoven and 200 kGy in laminate materials. The tensile strength and the elongation decrease slowly for the nonwoven textile and decrease faster for the laminate textile for 25 and 80 kGy absorbed dose. This paper shows that the DSC and TGA techniques can be helpful for the prevision of mechanical changes occurred in the materials as a consequence of the gamma irradiation.

  12. Does the Blazar Gamma-ray Spectrum Harden with Increasing Flux? - Analysis of Nine Years of EGRET Data

    NASA Technical Reports Server (NTRS)

    Nandikotkur, Giridhar; Jahoda, Keith M.; Hartman, R. C.; Mukherjee, R.; Sreekumar, P.; Boettcher, M.

    2007-01-01

    The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) discovered gamma-ray emission from more than 67 blazars during its nine-year lifetime. We conducted an exhaustive search of the EGRET archives and selected all the blazars that were observed multiple times and were bright enough to enable a spectral analysis using standard powerlaw models. The sample consists of 18 flat-spectrum radio quasars (FSRQs), 6 low-frequency-peaked BL Lacs (LBLs) and 2 high-frequency-peaked BL Lacs (HBLs). We do not detect any clear pattern in'the variation of spectral index with flux. Some of the blazars do not show any statistical evidence for spectral variability. The spectrum hardens with increasing flux in a few cases. There is also evidence for a flux-hardness anticorrelation at lo\\v fluxes in five blazars. The well observed blazars (3C 279,3C 273, PKS 0528-i-134, PKS 1622-297, PKS 0208- 512) do not show any overall trend in the long-term spectral dependence on flux, but the sample shows a mixture of hard and soft states. We observed spectral hysteresis at weekly timescales in all the three FSRQs for which data from flares lasting for 3 approx. 4 weeks were available. All three sources show a counterclockwise rotation despite the widely different flux profiles. Hysteresis in the spectral index vs. flux space has never been observed in FSRQs in gamma-rays at weekly timescales. itre analyze the observed spectral behavior in the context of various inverse-Compton mechanisms believed to be responsible for emission in the EGRET energy range. Our analysis uses the EGRET skymaps that were regenerated to include the changes in performance during the mission.

  13. Mathematical model of gamma-ray spectrometry borehole logging for quantitative analysis

    USGS Publications Warehouse

    Schimschal, Ulrich

    1981-01-01

    A technique for analyzing gamma-ray spectral-logging data has been developed, in which a digital computer is used to calculate the effects of gamma-ray attentuation in a borehole environment. The computer model allows for the calculation of the effects of lithology, porosity, density, and the thickness of a horizontal layer of uniformly distributed radioactive material surrounding a centralized probe in a cylindrical borehole. The computer program also contains parameters for the calculation of the effects of well casing, drilling fluid, probe housing, and losses through the sodium-iodide crystal. Errors associated with the commonly used mathematical assumption of a point detector are eliminated in this model. (USGS)

  14. An Analysis of Gamma-ray Burst Time Profiles from the Burst and Transient Source Experiment

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1996-01-01

    This proposal requested funding to measure the durations of gamma-ray bursts (GRB) in the 4B catalog as well as to study the structure of GRB time profiles returned by the Burst And Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory. The duration (T90) was to be measured using the same techniques and algorithms developed by the principal investigator for the 3B data. The profile structure studies fall into the two categories of variability and fractal analyses.

  15. Analysis and results of the 104Sn Coulomb excitation experiment

    NASA Astrophysics Data System (ADS)

    Guastalla, G.; DiJulio, D. D.; Górska, M.; Cederkäll, J.; Boutachkov, P.; Golubev, P.; Pietri, S.; Grawe, H.; Nowacki, F.; Algora, A.; Ameil, F.; Arici, T.; Atac, A.; Bentley, M. A.; Blazhev, A.; Bloor, D.; Brambilla, S.; Braun, N.; Camera, F.; Domingo Pardo, C.; Estrade, A.; Farinon, F.; Gerl, J.; Goel, N.; Grȩbosz, J.; Habermann, T.; Hoischen, R.; Jansson, K.; Jolie, J.; Jungclaus, A.; Kojouharov, I.; Knoebel, R.; Kumar, R.; Kurcewicz, J.; Kurz, N.; Lalović, N.; Merchan, E.; Moschner, K.; Naqvi, F.; Nara Singh, B. S.; Nyberg, J.; Nociforo, C.; Obertelli, A.; Pfützner, M.; Pietralla, N.; Podolyák, Z.; Prochazka, A.; Ralet, D.; Reiter, P.; Rudolph, D.; Schaffner, H.; Schirru, F.; Scruton, L.; Swaleh, T.; Taprogge, J.; Wadsworth, R.; Warr, N.; Weick, H.; Wendt, A.; Wieland, O.; Winfield, J. S.; Wollersheim, H. J.

    2014-09-01

    The analysis of the Coulomb excitation experiment conducted on 104Sn required a strict selection of the data in order to reduce the large background present in the γ-ray energy spectra and identify the γ-ray peak corresponding to the Coulomb excitation events. As a result the B(E2; 0+ → 2+) value could be extracted, which established the downward trend towards 100Sn and therefore the robustness of the N=Z=50 core against quadrupole excitations.

  16. ETRAN--R Extension Package for Eye Tracking Results Analysis.

    PubMed

    Zhegallo, Alexander V; Marmalyuk, Pavel A

    2015-01-01

    Novel open source R extension package for general-purpose eye tracking results analysis proposed. Now supported features are data loading from SMI eye trackers, different methods of fixations detection, various imaging techniques for raw data, and detected fixations (time sequence, scanpath, heatmap, and dynamic visualization). The modular structure of the package and a detailed description of each function provide a convenient way to further extend the functionality. Effective use of package requires knowledge of R programming language and environment. PMID:26562926

  17. The GLOBE Contrail Protocol: Initial Analysis of Results

    NASA Technical Reports Server (NTRS)

    Chambers, Lin; Duda, David

    2004-01-01

    The GLOBE contrail protocol was launched in March 2003 to obtain surface observer reports of contrail occurrence to complement satellite and model studies underway at NASA Langley, among others. During the first year, more than 30,000 ground observations of contrails were submitted to GLOBE. An initial analysis comparing the GLOBE observations to weather prediction model results for relative humidity at flight altitudes is in progress. This paper reports on the findings to date from this effort.

  18. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

  19. STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  20. STATISTICAL ANALYSIS OF TANK 19F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 19F as per the statistical sampling plan developed by Harris and Shine. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL95%) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current scrape sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 19F. The uncertainty is quantified in this report by an UCL95% on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL95% was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  1. SCD1 thermal design and test result analysis

    NASA Technical Reports Server (NTRS)

    Cardoso, Humberto Pontes; Muraoka, Issamu; Mantelli, Marcia Barbosa Henriques; Leite, Rosangela M. G.

    1990-01-01

    The SCD 01 (Satelite de Coleta de Dados 01) is a spin stabilized low Earth orbit satellite dedicated to the collection and distribution of environmental data. It was completely developed at the Brazilian Institute for Space Research (INPE) and is scheduled to be launched in 1992. The SCD 01 passive thermal control design configuration is presented and the thermal analysis results are compared with the temperatures obtained from a Thermal Balance Test. The correlation between the analytical and experimental results is considered very good. Numerical flight simulations show that the thermal control design can keep all the subsystem temperatures within their specified temperature range.

  2. Methods and results of a search for gravitational waves associated with gamma-ray bursts using the GEO 600, LIGO, and Virgo detectors

    NASA Astrophysics Data System (ADS)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Affeldt, C.; Agathos, M.; Aggarwal, N.; Aguiar, O. D.; Ajith, P.; Alemic, A.; Allen, B.; Allocca, A.; Amariutei, D.; Andersen, M.; Anderson, R. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Areeda, J. S.; Ast, S.; Aston, S. M.; Astone, P.; Aufmuth, P.; Augustus, H.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P. T.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barbet, M.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bauchrowitz, J.; Bauer, Th. S.; Baune, C.; Bavigadda, V.; Behnke, B.; Bejger, M.; Beker, M. G.; Belczynski, C.; Bell, A. S.; Bell, C.; Bergmann, G.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biscans, S.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bond, C.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, Sukanta; Bosi, L.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brückner, F.; Buchman, S.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burman, R.; Buskulic, D.; Buy, C.; Cadonati, L.; Cagnoli, G.; Cain, J.; Calderón Bustillo, J.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannon, K. C.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Carbone, L.; Caride, S.; Castaldi, G.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Celerier, C.; Cella, G.; Cepeda, C.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, X.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S. S. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J. A.; Clayton, J. H.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C.; Colombini, M.; Cominsky, L.; Constancio, M.; Conte, A.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Coulon, J.-P.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Croce, R. P.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, C.; Dahl, K.; Dal Canton, T.; Damjanic, M.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daveloza, H.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; Dayanga, T.; DeBra, D.; Debreczeni, G.; Degallaix, J.; Deléglise, S.; Del Pozzo, W.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Virgilio, A.; Dolique, V.; Dominguez, E.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S.; Eberle, T.; Edo, T.; Edwards, M.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Endrőczi, G.; Essick, R.; Etzel, T.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fazi, D.; Fehrmann, H.; Fejer, M. M.; Feldbaum, D.; Feroz, F.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Fotopoulos, N.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S.; Garufi, F.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, C.; Gleason, J.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Goßler, S.; Gouaty, R.; Gräf, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Groot, P.; Grote, H.; Grover, K.; Grunewald, S.; Guidi, G. M.; Guido, C. J.; Gushwa, K.; Gustafson, E. K.; Gustafson, R.; Ha, J.; Hall, E. D.; Hamilton, W.; Hammer, D.; Hammond, G.; Hanke, M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Haris, K.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hart, M.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Holt, K.; Hopkins, P.; Horrom, T.; Hoske, D.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hu, Y.; Huerta, E.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh, M.; Huynh-Dinh, T.; Idrisy, A.; Ingram, D. R.; Inta, R.; Islas, G.; Isogai, T.; Ivanov, A.; Iyer, B. R.; Izumi, K.; Jacobson, M.; Jang, H.; Jaranowski, P.; Ji, Y.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Jonker, R. J. G.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karlen, J.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Keiser, G. M.; Keitel, D.; Kelley, D. B.; Kells, W.; Keppel, D. G.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, C.; Kim, K.; Kim, N. G.; Kim, N.; Kim, S.; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kline, J.; Koehlenbeck, S.; Kokeyama, K.; Kondrashov, V.; Koranda, S.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, A.; Kumar, D. Nanda; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lam, P. K.; Landry, M.; Lantz, B.; Larson, S.; Lasky, P. D.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, J.; Lee, P. J.; Leonardi, M.; Leong, J. R.; Le Roux, A.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B.; Lewis, J.; Li, T. G. F.; Libbrecht, K.; Libson, A.; Lin, A. C.; Littenberg, T. B.; Lockerbie, N. A.; Lockett, V.; Lodhia, D.; Loew, K.; Logue, J.; Lombardi, A. L.; Lopez, E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J.; Lubinski, M. J.; Lück, H.; Lundgren, A. P.; Ma, Y.; Macdonald, E. P.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R.; Mageswaran, M.; Maglione, C.; Mailand, K.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Manca, G. M.; Mandel, I.; Mandic, V.; Mangano, V.; Mangini, N. M.; Mansell, G.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Martinelli, L.; Martynov, D.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Matichard, F.; Matone, L.; Mavalvala, N.; May, G.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIver, J.; McLin, K.; Meacher, D.; Meadors, G. D.; Mehmet, M.; Meidam, J.; Meinders, M.; Melatos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, A.; Meyer, M. S.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Mikhailov, E. E.; Milano, L.; Miller, J.; Minenkov, Y.; Mingarelli, C. M. F.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Morgado, N.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nagy, M. F.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nelemans, G.; Neri, I.; Neri, M.; Newton, G.; Nguyen, T.; Nielsen, A. B.; Nissanke, S.; Nitz, A. H.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Ochsner, E.; O'Dell, J.; Oelker, E.; Oh, J. J.; Oh, S. H.; Ohme, F.; Omar, S.; Oppermann, P.; Oram, R.; O'Reilly, B.; Ortega, W.; O'Shaughnessy, R.; Osthelder, C.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Padilla, C.; Pai, A.; Palashov, O.; Palomba, C.; Pan, H.; Pan, Y.; Pankow, C.; Paoletti, F.; Papa, M. A.; Paris, H.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patel, P.; Pedraza, M.; Pele, A.; Penn, S.; Perreca, A.; Phelps, M.; Pichot, M.; Pickenpack, M.; Piergiovanni, F.; Pierro, V.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poeld, J.; Poggiani, R.; Poteomkin, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qin, J.; Quetschke, V.; Quintero, E.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Raja, S.; Rajalakshmi, G.; Rakhmanov, M.; Ramet, C.; Ramirez, K.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Recchia, S.; Reed, C. M.; Regimbau, T.; Reid, S.; Reitze, D. H.; Reula, O.; Rhoades, E.; Ricci, F.; Riesen, R.; Riles, K.; Robertson, N. A.; Robinet, F.; Rocchi, A.; Roddy, S. B.; Rogstad, S.; Rolland, L.; Rollins, J. G.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Salemi, F.; Sammut, L.; Sandberg, V.; Sanders, J. R.; Sankar, S.; Sannibale, V.; Santiago-Prieto, I.; Saracco, E.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Savage, R.; Scheuer, J.; Schilling, R.; Schilman, M.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shah, S.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sidery, T. L.; Siellez, K.; Siemens, X.; Sigg, D.; Simakov, D.; Singer, A.; Singer, L.; Singh, R.; Sintes, A. M.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, R. J. E.; Smith-Lefebvre, N. D.; Son, E. J.; Sorazu, B.; Souradeep, T.; Staley, A.; Stebbins, J.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Stephens, B. C.; Steplewski, S.; Stevenson, S.; Stone, R.; Stops, D.; Strain, K. A.; Straniero, N.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tao, J.; Tarabrin, S. P.; Taylor, R.; Tellez, G.; Thirugnanasambandam, M. P.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Travasso, F.; Traylor, G.; Trias, M.; Tse, M.; Tshilumba, D.; Tuennermann, H.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; van der Sluys, M. V.; van Heijningen, J.; van Veggel, A. A.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vincent-Finley, R.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vousden, W. D.; Vyachanin, S. P.; Wade, A. R.; Wade, L.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, M.; Wang, X.; Ward, R. L.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; White, D. J.; Whiting, B. F.; Wiesner, K.; Wilkinson, C.; Williams, K.; Williams, L.; Williams, R.; Williams, T. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Wittel, H.; Woan, G.; Wolovick, N.; Worden, J.; Wu, Y.; Yablon, J.; Yakushin, I.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yang, H.; Yoshida, S.; Yvert, M.; ZadroŻny, A.; Zanolin, M.; Zendri, J.-P.; Zhang, Fan; Zhang, L.; Zhao, C.; Zhu, H.; Zhu, X. J.; Zucker, M. E.; Zuraw, S.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

    2014-06-01

    In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz-1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO 600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties, for example the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well localized, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of O(10) for GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the method of the linear grid in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO 600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, under an assumption of a fixed GW emission energy of 10-2M⊙c2, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events once the advanced LIGO and Virgo detectors begin operation.

  3. Methods and Results of a Search for Gravitational Waves Associated with Gamma-Ray Bursts Using the GEO 600, LIGO, and Virgo Detectors

    NASA Technical Reports Server (NTRS)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Blackburn, Lindy L.; Camp, Jordan B.; Gehrels, N.; Graff, P. B.; Slutsky, J. P.

    2013-01-01

    In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz-1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties such as the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well-localized, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of O(10) for GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the linear search grid method in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, assuming a fixed GW emission energy of 10(exp -2)Stellar Mass sq c, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events in the Advanced detector era.

  4. Recent results from TRISTAN

    SciTech Connect

    Enomoto, Ryoji

    1997-01-01

    TRISTAN results on {gamma}{gamma} physics from 1994 to 1995 are reviewed in this report. We have systematically investigated jet production, the {gamma}-structure function, and charm pair production in {gamma}{gamma} processes. The results are discussed, and future prospects are presented.

  5. Dalitz Analysis of D0 to K0(S) Pi+ Pi- and Measurement of the CKM Angle Gamma in Charged B+- Decays to D(*) K+- Decays

    SciTech Connect

    Lau, Yan-Pan

    2007-07-10

    Despite more than thirty years having elapsed since the discovery of CP violation, our understanding about the source and the nature of this phenomenon is still very limited. In the standard model of particle physics, CP violation is due to the presence of an non-irreducible weak phase in the Cabibbo-Kabayashi-Maskawa(CKM) matrix. Up to now, all the experimental results are in good agreement with the standard model. However, it is important for us to over-constrain the CKM quark-mixing matrix and explore the possibility of new physics beyond the standard model. The B meson provides an ideal place to measure CP violation due to its heavy mass and potentially large CP-violating effects. In particular, the angle {gamma} of the Unitary Triangle relating the elements of the CKM matrix is extremely crucial in terms of CP violation and constraints on the new physics models. Various methods using B{sup -} {yields} D{sup 0}K{sup -} decays have been proposed to measure based on the interference between the V{sub cb} and V{sub ub} amplitudes. Despite the simple concept, the measurement turns out to be experimentally challenging due to the small branching fraction and the small value of {tau}{sub B}, the amplitude ratio between the two contributing Feynman diagrams. In this thesis a novel technique to measure {gamma} in B{sup -} {yields} D{sup (*)} K{sup -} decay using a Dalitz plot analysis of D{sup 0} {yields} K{sub s}{pi}{sup +}{pi}{sup -} is presented. Until the turn on of LHC{sub b} [1] later in the decade, this remains the most promising method to measure {gamma}. This thesis is roughly separated into two parts. The first part involves a study of hadron spectroscopy and the Dalitz plot analysis of the D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -}. The second part of the thesis involves the measurement of {gamma} in B{sup -} {yields} D{sup (*)} K{sup -} using the results of the D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} dalitz plot analysis.

  6. Nano {gamma}'/{gamma}'' composite precipitates in Alloy 718

    SciTech Connect

    Phillips, P. J.; McAllister, D.; Gao, Y.; Lv, D.; Williams, R. E. A.; Wang, Y.; Mills, M. J.; Peterson, B.

    2012-05-21

    Nanoscale composite precipitates of Alloy 718 have been investigated with both high-resolution scanning transmission electron microscopy and phase field modeling. Chemical analysis via energy-dispersive x-ray spectroscopy allowed for the differentiation of {gamma}' and {gamma}'' particles, which is not otherwise possible through traditional Z-contrast methods. Phase field modeling was applied to determine the stress distribution and elastic interaction around and between the particles, respectively, and it was determined that a composite particle (of both {gamma}' and {gamma}'') has an elastic energy that is significantly lower than, for example, single {gamma}' and {gamma}'' precipitates which are non-interacting.

  7. Analysis and Summary of Historical Dry Well Gamma Logs for S Tank Farm 200 West

    SciTech Connect

    MYERS, D.A.

    1999-11-22

    Gross gamma ray logs, recorded from January 1975 through mid-year 1994 as part of the Single-Shell Tank Farm Dry Well Surveillance Program, have been reanalyzed for the S tank farm to locate the presence of mobile radionuclides in the subsurface.

  8. A validated method for gas chromatographic analysis of gamma-aminobutyric acid in tall fescue herbage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gamma-Aminobutyric acid (GABA) is an inhibitory neurotransmitter in animals that is also found in plants and has been associated with plant responses to stress. A simple and relatively rapid method of GABA separation and quantification was developed from a commercially available kit for serum amino...

  9. Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Source output stability is important for accurate measurement in prompt gamma neutron activation. This is especially true when measuring low-concentration elements such as in vivo nitrogen (~2.5% of body weight). We evaluated the stability of the compact DT neutron generator within an in vivo nitrog...

  10. Gamma ray spectroscopic analysis of building materials used in Tiruvannamalai, Tamilnadu, India

    SciTech Connect

    Ravisankar, R.; Vanasundari, K.; Suganya, M.; Chandrasekaran, A.; Raghu, Y.; Sivakumar, S.; Vijayagopal, P.; Meenakshisundaram, V.

    2012-06-05

    Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials in Tiruvannamalai, city, have been collected randomly over the city. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. All samples under investigation are within the recommended safety limit when used as building construction.

  11. Analysis of Induced Gamma Activation by D-T Neutrons in Selected Fusion Reactor Relevant Materials with EAF-2010

    NASA Astrophysics Data System (ADS)

    Klix, Axel; Fischer, Ulrich; Gehre, Daniel

    2016-02-01

    Samples of lanthanum, erbium and titanium which are constituents of structural materials, insulating coatings and tritium breeder for blankets of fusion reactor designs have been irradiated in a fusion peak neutron field. The induced gamma activities were measured and the results were used to check calculations with the European activation system EASY-2010. Good agreement for the prediction of major contributors to the contact dose rate of the materials was found, but for minor contributors the calculation deviated up to 50%.

  12. The particle-gamma coincidence method: A brief introduction

    SciTech Connect

    Mayer, J.; Derya, V.; Endres, J.; Hennig, A.; Netterdon, L.; Pascu, S.; Pickstone, S. G.; Sauerwein, A.; Scholz, P.; Spieker, M.; Streit, T.-M.; Zilges, A.

    2013-06-10

    Excitation energy information from particle detectors can significantly improve the analysis process of {gamma}-ray spectra and result in more detailed nuclear structure information. Therefore, a new setup at the HORUS {gamma}-ray spectrometer at the University of Cologne has been installed, housing silicon particle detectors at up to eight positions.

  13. Determination of the illicit drug gamma-hydroxybutyrate (GHB) in human saliva and beverages by 1H NMR analysis.

    PubMed

    Grootveld, Martin; Algeo, Deborah; Silwood, Christopher J L; Blackburn, John C; Clark, Anthony D

    2006-01-01

    High resolution 1H NMR spectroscopy has been employed to investigate the detection and quantification of the illicit "date-rape" drug gamma-hydroxybutyrate (GHB) in both human saliva and a commonly-consumed low-alcohol beer product. Data acquired revealed that this multicomponent analytical technique provided unequivocal evidence for the detection of this agent by this technique in both of these matrices, i.e., all three of its resonances [those ascribable to the alpha-CH2 (t, delta=2.25 ppm), beta-CH2 (tt, delta=1.81 ppm) and gamma-CH2 (t, delta=3.61 ppm) group protons] were present in spectra acquired on human saliva, and two of these (the alpha- and beta-CH2 group signals) in the beverage product examined, the latter observation attributable to overlap of the gamma-CH2 1H resonance with those of carbohydrates. Since good linear calibration relationships between the intensities of each of the NMR-visible signals and added GHB concentration (the former normalised to that of an external 3-trimethylsilyl [2,2,3,3-2H4]- propionate standard present in a coaxial NMR tube insert) were observed, this illicit drug is also readily quantifiable in such multicomponent samples. Our data demonstrate the advantages offered by this technique when applied to the analysis of illicit drugs in multicomponent sample matrices such as human biofluids and beverage products. PMID:17012769

  14. Synchronization of Firing in Cortical Fast-Spiking Interneurons at Gamma Frequencies: A Phase-Resetting Analysis

    PubMed Central

    Tsumoto, Kunichika; Tateno, Takashi; Aihara, Kazuyuki; Robinson, Hugh P. C.

    2010-01-01

    Fast-spiking (FS) cells in the neocortex are interconnected both by inhibitory chemical synapses and by electrical synapses, or gap-junctions. Synchronized firing of FS neurons is important in the generation of gamma oscillations, at frequencies between 30 and 80 Hz. To understand how these synaptic interactions control synchronization, artificial synaptic conductances were injected in FS cells, and the synaptic phase-resetting function (SPRF), describing how the compound synaptic input perturbs the phase of gamma-frequency spiking as a function of the phase at which it is applied, was measured. GABAergic and gap junctional conductances made distinct contributions to the SPRF, which had a surprisingly simple piecewise linear form, with a sharp midcycle break between phase delay and advance. Analysis of the SPRF showed how the intrinsic biophysical properties of FS neurons and their interconnections allow entrainment of firing over a wide gamma frequency band, whose upper and lower frequency limits are controlled by electrical synapses and GABAergic inhibition respectively. PMID:20941393

  15. Recent Results from CHAMP Tracking and Accelerometer Data Analysis

    NASA Technical Reports Server (NTRS)

    Luthcke, S. B.; Rowlands, D. D.; Lemoine, F. G.; Nerem, R. S.; Thompson, B.; Pavlis, E.; Williams, T. A.; Colombo, O. L.; Chao, Benjamin F. (Technical Monitor)

    2002-01-01

    The CHAMP mission's unique combination of sensors and orbit configuration will enable unprecedented improvements in modeling and understanding the Earth's static gravity field and its temporal variations. CHAMP is the first of two missions (GRACE to be launched in the early part of 02') that combine a new generation of Global Positioning System (GPS) receivers, a high precision three-axis accelerometer, and star cameras for the precision attitude determination. In order to isolate the gravity signal for science investigations, it is necessary to perform a detailed reduction and analysis of the GPS and Satellite Laser Ranging (SLR) tracking data in conjunction with the accelerometer and attitude data. Precision orbit determination based on the GPS and SLR tracking data will isolate the orbit perturbations, while the accelerometer data will be used to distinguish the non-gravitational forces from those due to the geopotential (static, and time varying). In preparation for the CHAMP and GRACE missions, extensive modifications have been made to NASA/GSFC's GEODYN orbit determination software to enable the simultaneous reduction of spacecraft tracking (e.g. GPS and SLR), three-axis accelerometer and precise attitude data. Several weeks of CHAMP tracking and accelerometer data have been analyzed and the results will be presented. Precision orbit determination analysis based on tracking data alone in addition to results based on the simultaneous reduction of tracking and accelerometer data will be discussed. Results from a calibration of the accelerometer will be presented along with the results from various orbit determination strategies.

  16. Analysis of Data from the Transient Gamma-Ray Spectrometer Experiment on the GGS/Wind Spacecraft

    NASA Technical Reports Server (NTRS)

    Hurley, K.

    1997-01-01

    The data analysis from the TGRS experiment is continuing, although the UC Berkeley PI, K. Hurley, is no longer funded for this effort. This experiment has been returning data on the energy spectra and time histories of cosmic gamma-ray bursts since November 1994, and continues to operate in good health. Over a 3 year period ending in November 1997, 41 bursts have been detected simultaneously by TGRS and Dr. Hurley's Ulysses gamma-ray burst experiment. By comparing the times of arrival of a burst at Ulysses and TGRS, we can obtain an annulus of arrival directions for the event. Typical 3sigma annulus widths range from several arcminutes to tens of arcminutes. Because the WIND spacecraft is as far as several light-seconds from Earth, it is sometimes possible to obtain a second annulus using the Burst and Transient Source Experiment (BATSE) aboard the GRO spacecraft. 23 of the 41 bursts were also observed by this experiment. Generally, the two annuli intersect at grazing incidence, leading to a long, narrow error box which reduces somewhat the error circles obtained from BATSE alone. Table 1 summarizes the burst data from TGRS. We plan to defer the publication of these locations until a larger number of events has been accumulated. Measuring the energy spectra of cosmic gamma-ray bursts to search for line emission is one of the prime objectives of this experiment. However, an intense gamma-ray burst is required, or the statistics become too weak to draw meaningful conclusions. One such event has occurred to date, on August 22, 1995, and we have examined it in detail. The spectrum shows no evidence for lines, however.

  17. Solar neutrinos results and oscillation analysis from Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Koshio, Yusuke

    The results of the solar neutrino spectrum measurement in Super-Kamiokande is presented. The precise measurement of the solar neutrino enegy spectrum is one of the most important key issue to understand neutrino oscillations. In order to measure the spectrum, it is very important to precisely determin the energy scale of the detector. For this purpose, we have used an electron LINAC. This calibration can be done at several positions, directions and energy points, and it can reduce the systematic errors of energy scale less than 1. Neutrino oscillations are essentially energy dependent phenomena. Actually different solar neutrino oscillation solutions require the different energy dependece. In addition, such a measurement is independent the absolute flux results of solar models. Therefore an observation of the deviation from the expected energy spectrum not only show the definite evidence of the solar neutrino oscillation, but also differenciate the possible oscillation solutions. The results of the extensive analysis on neutrino oscillation is presented.

  18. Analysis of vehicle fuel release resulting in waste tank fire

    SciTech Connect

    HARRIS, J.P.

    2003-10-14

    The purpose of the calculation documented here is to support in-tank vehicle fuel fire accident frequencies in the Documented Safety Analysis. This analysis demonstrates that the frequency of the pool fire and deflagration scenarios of the in-tank vehicle fuel fire/deflagration accident are ''extremely unlikely'' to ''unlikely.'' The chains of events that result in each scenario are presented in this document and are the same as used in previous analyses of this accident. Probabilities and frequencies are developed for each event, using wherever possible, information from RPP-13121, Tables B-1 and B-2, and from the River Protection Project ORPS. The estimated probabilities are considered reasonably conservative, but do not necessarily assume the worst possible outcomes or the most conservative possible cases. A sensitivity analysis performed in Section 4.2 shows that if the probability of either the ignition of fuel event or the fuel flows into riser event were underestimated by an order of magnitude, the accident frequency for a pool fire could increase and shift into the ''unlikely'' category. If the probability of an increase in riser strikes, or an increase in broken risers, unignited fuel entering a riser, or a fuel ignition source being present in a tank were underestimated by an order of magnitude, the accident frequency for a deflagration would remain in the ''unlikely'' category. When the likelihood of a broken riser is increased by an order of magnitude, a pool fire remains in the ''extremely unlikely'' category. The DSA accident analysis indicates that an unmitigated flammable gas deflagration resulting from an induced gas release event or an organic solvent fire occurring in either an SST or a DST is an anticipated event (> 10{sup -2}). Deflagration in a DST annulus is considered unlikely (> 10{sup -4} to {le}10{sup -2}). These frequencies clearly bound those of the in-tank vehicle fuel fire family of accidents.

  19. mBAND Analysis of Early and Late Damages in the Chromosome of Human Lymphocytes after Exposures to Gamma Rays and Fe Ions

    NASA Technical Reports Server (NTRS)

    Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2013-01-01

    Stable type chromosome aberrations that survive multiple generations of cell division include translocation and inversions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. At the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Detailed analysis of breaks participating in total chromosome exchanges within the first cell cycle post irradiation revealed a common hotspot located in the 3p21 region, which is a known fragile site corresponding to the band 6 in the mBand analysis. The breakpoint distribution in chromosomes collected at 7 days, but not at 14 days, post irradiation appeared similar to the distribution in cells collected within the first cell cycle post irradiation. The breakpoint distribution for human lymphocytes after radiation exposure was different from the previously published distribution for human

  20. An analysis of nuclear fuel burnup in the AGR-1 TRISO fuel experiment using gamma spectrometry, mass spectrometry, and computational simulation techniques

    DOE PAGESBeta

    Harp, Jason M.; Demkowicz, Paul A.; Winston, Philip L.; Sterbentz, James W.

    2014-09-03

    AGR 1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR 1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR 1 experiment. Two methodsmore » for evaluating burnup by gamma spectrometry were developed, one based on the Cs 137 activity and the other based on the ratio of Cs 134 and Cs 137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1% FIMA for the direct method and 20.0% FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3% FIMA to 10.7% FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma spectrometry burnup evaluations and the expected burnup from simulation. For all four compacts analyzed by mass spectrometry, the maximum range in the three experimentally determined values and the predicted value was 6% or less. Furthermore, the results confirm the accuracy of the nondestructive burnup evaluation from gamma

  1. An analysis of nuclear fuel burnup in the AGR-1 TRISO fuel experiment using gamma spectrometry, mass spectrometry, and computational simulation techniques

    SciTech Connect

    Harp, Jason M.; Demkowicz, Paul A.; Winston, Philip L.; Sterbentz, James W.

    2014-09-03

    AGR 1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR 1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR 1 experiment. Two methods for evaluating burnup by gamma spectrometry were developed, one based on the Cs 137 activity and the other based on the ratio of Cs 134 and Cs 137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1% FIMA for the direct method and 20.0% FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3% FIMA to 10.7% FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma spectrometry burnup evaluations and the expected burnup from simulation. For all four compacts analyzed by mass spectrometry, the maximum range in the three experimentally determined values and the predicted value was 6% or less. Furthermore, the results confirm the accuracy of the nondestructive burnup evaluation from gamma spectrometry

  2. Wind tunnel test IA300 analysis and results, volume 1

    NASA Technical Reports Server (NTRS)

    Kelley, P. B.; Beaufait, W. B.; Kitchens, L. L.; Pace, J. P.

    1987-01-01

    The analysis and interpretation of wind tunnel pressure data from the Space Shuttle wind tunnel test IA300 are presented. The primary objective of the test was to determine the effects of the Space Shuttle Main Engine (SSME) and the Solid Rocket Booster (SRB) plumes on the integrated vehicle forebody pressure distributions, the elevon hinge moments, and wing loads. The results of this test will be combined with flight test results to form a new data base to be employed in the IVBC-3 airloads analysis. A secondary objective was to obtain solid plume data for correlation with the results of gaseous plume tests. Data from the power level portion was used in conjunction with flight base pressures to evaluate nominal power levels to be used during the investigation of changes in model attitude, eleveon deflection, and nozzle gimbal angle. The plume induced aerodynamic loads were developed for the Space Shuttle bases and forebody areas. A computer code was developed to integrate the pressure data. Using simplified geometrical models of the Space Shuttle elements and components, the pressure data were integrated to develop plume induced force and moments coefficients that can be combined with a power-off data base to develop a power-on data base.

  3. Analysis of gunshot residue test results in 112 suicides.

    PubMed

    Reed, G E; McGuire, P J; Boehm, A

    1990-01-01

    The results of gunshot residue (GSR) tests in 112 suicide cases investigated by the U.S. Army Criminal Investigation Command over a ten-year period are described. Only suicide cases in which there was certainty that the victim fired a weapon were examined in an effort to reduce ambiguous results. Previous case work research by Rudzitis indicated that positive GSR test results were encountered in suicides 62% of the time using various combinations of neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS). Threshold values of 0.2-micrograms antimony and 0.3-micrograms barium (0.2-micrograms antimony and 0.5-micrograms barium after 1985) used by the U.S. Army Criminal Investigation Laboratory resulted in positive GSR results in suicide cases 38% of the time. The effects of time, location of body, handling of the body, weapon type, caliber, and condition of the hands on GSR results are examined. Case studies involving suicides by unit armorers are discussed. PMID:2313262

  4. Preliminary results of a gamma-ray burst study in the Konus experiment on the Venera-11 and Venera-12 space probes

    NASA Technical Reports Server (NTRS)

    Mazets, Y. P.; Golentskiy, S. V.; Ilinskiy, V. N.; Panov, V. N.; Aptekar, R. L.; Guryan, Y. A.; Sokolov, I. A.; Sokolova, Z. Y.; Kharitonova, T. V.

    1979-01-01

    Twenty-one gamma-ray bursts and 68 solar flares in the hard X-ray range were detected on Venera-11 and Venera-12 space probes during the initial 50-day observation period. Major characteristics of the equipment used and preliminary data on the temporal structure and energy spectra of the gamma-ray bursts are considered. The pattern of gamma-ray burst frequency distribution vs. intensity, N(S), is established.

  5. Genetic aspect of Alzheimer disease: Results of complex segregation analysis

    SciTech Connect

    Sadonvick, A.D.; Lee, I.M.L.; Bailey-Wilson, J.E.

    1994-09-01

    The study was designed to evaluate the possibility that a single major locus will explain the segregation of Alzheimer disease (AD). The data were from the population-based AD Genetic Database and consisted of 402 consecutive, unrelated probands, diagnosed to have either `probable` or `autopsy confirmed` AD and their 2,245 first-degree relatives. In this analysis, a relative was considered affected with AD only when there were sufficient medical/autopsy data to support diagnosis of AD being the most likely cause of the dementia. Transmission probability models allowing for a genotype-dependent and logistically distributed age-of-onset were used. The program REGTL in the S.A.G.E. computer program package was used for a complex segregation analysis. The models included correction for single ascertainment. Regressive familial effects were not estimated. The data were analyzed to test for single major locus (SML), random transmission and no transmission (environmental) hypotheses. The results of the complex segregation analysis showed that (1) the SML was the best fit, and (2) the non-genetic models could be rejected.

  6. Analysis and modelling results using CHAMP/STAR density data

    NASA Astrophysics Data System (ADS)

    Bruinsma, S. L.

    The CHAMP mission profile is particularly interesting for upper atmosphere studies since it provides a nearly complete latitudinal coverage while complete solar local time sampling is achieved approximately every four months Total atmospheric densities have been derived from STAR accelerometer measurements from May 2001 through December 2005 During that time CHAMP has measured the response of the thermosphere to virtually every significant geomagnetic storm including the largest one ever recorded Satellite and instruments are still healthy in a few years CHAMP will very probably be the first mission to provide the community with consistent and geographically well-distributed density data covering solar maximum to minimum Since March 2002 accelerometer data from the GRACE satellites can also be used to derive densities although a more complex processing is required A short analysis of CHAMP and GRACE density observations made when both satellites were in the same orbital plane will be given These densities can be used to study the following non-exhaustive list of topics 1-analysis of short- and long-term thermospheric variability 2-evaluation of proxy-indicators for solar or geomagnetic activity such as F10 7 the chromospheric Mg II index E10 7 sectorial kp 3-thermospheric wave activity travelling atmospheric disturbances related to solar storm events 4-thermosphere model error analysis and improvement An overview of results obtained over the last 5 years for these 4 topics is given Fall 2006 will mark the start of a major revision of

  7. Complete leading order analysis in Chiral Perturbation Theory of the decays K{sub L}{r_arrow}{gamma}{gamma} and K{sub L}{r_arrow}l{sub +}l{sub {minus}}{gamma}

    SciTech Connect

    J. L. Goity; Longzhe Zhang

    1997-02-01

    The decays K{sub L}{r_arrow}{gamma}{gamma} and K{sub L}{r_arrow}l{sup +}l{sup {minus}}{gamma} are studied at the leading order p{sup 6} in Chiral Perturbation Theory. One-loop contributions stemming from the odd intrinsic parity {vert_bar}{Delta}S{vert_bar}=1 effective Lagrangian of order p{sup 4} are included and shown to be of possible relevance. They affect the decay K{sub L}{r_arrow}{gamma}{gamma} adding to the usual pole terms a piece free of counterterm uncertainties. In the case of the K{sub L}{r_arrow}l{sup +}l{sup {minus}}{gamma} decays the dependence of the form factor on the dilepton invariant mass requires a counterterm. The form factor may receive a sizeable contribution from chiral logarithms. Including considerations from the K{sub L}{r_arrow}{pi}{sup +}{pi}{sup {minus}}{gamma} direct emission amplitude, the authors obtain two consistent scenarios. In one scenario the long distance contributions from the one-loop terms are important, while in the other they are marginal. In both cases the counterterm is shown to be significant.

  8. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    NASA Astrophysics Data System (ADS)

    Lambertin, D.; Boher, C.; Dannoux-Papin, A.; Galliez, K.; Rooses, A.; Frizon, F.

    2013-11-01

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with 60Co sources up to 1000 kGy. Various Na-geopolymer with three H2O/Na2O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation.

  9. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

    PubMed

    Schütz, C L; Brochhausen, C; Hampel, G; Iffland, D; Kuczewski, B; Otto, G; Schmitz, T; Stieghorst, C; Kratz, J V

    2012-10-01

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis. PMID:22918535

  10. Gamma ray transients

    NASA Technical Reports Server (NTRS)

    Cline, Thomas L.

    1987-01-01

    The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

  11. Critical composite joint subcomponents: Analysis and test results

    NASA Technical Reports Server (NTRS)

    Bunin, B. L.

    1983-01-01

    This program has been conducted to develop the technology for critical structural joints of a composite wing structure meeting design requirements for a 1990 commercial transport aircraft. A prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Load sharing between bolts in multirow joints was computed by a nonlinear analysis program (A4FJ) which was used both to assess the efficiency of different joint design concepts and to predict the strengths of large test articles representing a section from a wing root chord-wise splice. In most cases, the predictions were accurate to within a few percent of the test results. A highlight of these tests was the consistent ability to achieve gross-section failure strains on the order of 0.005 which represents a considerable improvement over the state of the art. The improvement was attained largely as the result of the better understanding of the load sharing in multirow joints provided by the analysis. The typical load intensity on the structural joints was about 40 to 45 thousand pound per inch in laminates having interspersed 37 1/2-percent 0-degree plies, 50-percent + or - 45-degrees plies and 12 1/2-percent 90-degrees plies. The composite material was Toray 300 fiber and Ciba-Geigy 914 resin, in the form of 0.010-inch thick unidirectional tape.

  12. Relationships proximate analysis results and higher heating values of lignites

    SciTech Connect

    Demirbas, A.

    2008-07-01

    In this study, the higher heating values (HHVs) of 26 lignite samples were calculated by using the proximate and elemental analyses data. The proximate analysis results such as volatile materials (VM), fixed carbon (FC) and HHV and the elemental analysis results such as carbon, hydrogen (H), oxygen (O), nitrogen (N) and sulfur (S) were determined for 26 lignite samples from different areas of Turkey. The lignite samples have been tested with particle size of 0-0.05 mm. The HHVs of 26 lignite samples obtained from different Turkish sources were determined experimentally and calculated from both ultimate and proximate analyses. HHVs of 26 the lignite samples can be calculated from the equation based modeling. The HHVs (MJ/kg) of the lignite samples as a function of fixed carbon (FC, wt%) or volatile materials (VM, %) was calculated from the following equations: HHV = 0.300FC + 11.117 (1) HHV = -0.323VM + 42.223 (2) where the correlation coefficients for Eqs. (1) and (2) were 0.9907 and 0.9862, respectively. The combustion heats calculated from Eqs. (1) and (2) showed mean differences of +3.9% and +0.3%, respectively. The HHVs (MJ/kg) of the lignite samples as a function of C, H, O, N, and S were calculated from a given equation where the correlation coefficients for the equation was 0.9891. HHVs calculated from this equation showed a mean deviation of +0.1.

  13. Multicomponent analysis of total COS-B gamma-ray data at intermediate lattitudes

    NASA Technical Reports Server (NTRS)

    Strong, A. W.; Bloemen, J. B. G. M.; Hemsen, W.; Mayer-Hasselwander, H. A.

    1985-01-01

    The final COS-B database was used to study the gamma ray emission in the latitude range 10 deg /b/ 20 deg in terms of a four component model. The emissivity spectrum of the local interstellar medium is derived and compared with that found in previous studies. The intensity-Compton component is determined from the fitting procedure and is in good agreement with theoretical values.

  14. An analysis of the structure of gamma ray burst time histories

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick; Fishman, G. J.; Meegan, C. A.; Wilson, R.B.; Paciesas, W. S.; Pendleton, G. N.; Moore, P.; Cody, H. E.

    1992-01-01

    If gamma-ray bursts (GRB) arise from a small number of distinctly different physical phenomena, then this might be revealed by a clustering of time profile characteristics into a small number of groups. A 'spike' counting algorithm was applied to 107 GRB profiles. Graphs of spike frequency and spike amplitude versus burst intensity and duration are presented. So far, no evidence of grouping is seen.

  15. Heterogeneity of Particle Deposition by Pixel Analysis of 2D Gamma Scintigraphy Images

    PubMed Central

    Xie, Miao; Zeman, Kirby; Hurd, Harry; Donaldson, Scott

    2015-01-01

    Abstract Background: Heterogeneity of inhaled particle deposition in airways disease may be a sensitive indicator of physiologic changes in the lungs. Using planar gamma scintigraphy, we developed new methods to locate and quantify regions of high (hot) and low (cold) particle deposition in the lungs. Methods: Initial deposition and 24 hour retention images were obtained from healthy (n=31) adult subjects and patients with mild cystic fibrosis lung disease (CF) (n=14) following inhalation of radiolabeled particles (Tc99m-sulfur colloid, 5.4 μm MMAD) under controlled breathing conditions. The initial deposition image of the right lung was normalized to (i.e., same median pixel value), and then divided by, a transmission (Tc99m) image in the same individual to obtain a pixel-by-pixel ratio image. Hot spots were defined where pixel values in the deposition image were greater than 2X those of the transmission, and cold spots as pixels where the deposition image was less than 0.5X of the transmission. The number ratio (NR) of the hot and cold pixels to total lung pixels, and the sum ratio (SR) of total counts in hot pixels to total lung counts were compared between healthy and CF subjects. Other traditional measures of regional particle deposition, nC/P and skew of the pixel count histogram distribution, were also compared. Results: The NR of cold spots was greater in mild CF, 0.221±0.047(CF) vs. 0.186±0.038 (healthy) (p<0.005) and was significantly correlated with FEV1 %pred in the patients (R=−0.70). nC/P (central to peripheral count ratio), skew of the count histogram, and hot NR or SR were not different between the healthy and mild CF patients. Conclusions: These methods may provide more sensitive measures of airway function and localization of deposition that might be useful for assessing treatment efficacy in these patients. PMID:25393109

  16. Evaluation of comparison and proficiency test results of gamma ray spectrometry at Jožef Stefan Institute from 1986 to 2014.

    PubMed

    Glavič-Cindro, Denis; Korun, Matjaž; Nečemer, Marijan; Vodenik, Branko; Zorko, Benjamin

    2016-03-01

    One of the best ways to demonstrate the performance and capabilities of testing laboratories is to participate successfully in different international comparison schemes and proficiency tests. The overview of all results of such schemes in the field of high resolution gamma-ray spectrometry where the Laboratory for Radioactivity Measurements (LMR) of the Jožef Stefan Institute (JSI), Slovenia, participated in years 1986-2014 is presented. Different schemes are compared, strong points and drawbacks of different providers and schemes regarding evaluation procedures, determination of reference values, reporting time, sets of radionuclides included in the samples and range of activities of different radionuclides are discussed. One of the main conclusions is that the comparison and proficiency test samples normally contain substantially larger activities than are usually detected in environmental samples. Therefore the capability of determination of activities close to detection limits is usually covered only by few schemes. PMID:26706285

  17. Results of 1998 spectral gamma-ray monitoring of boreholes at the 216-Z-1A tile field, 216-Z-9 trench, and 216-Z-12 crib

    SciTech Connect

    Horton, D.G.; Randall, R.R.

    1998-09-01

    This document describes the results of fiscal year 1998 vadose zone monitoring of three inactive liquid waste disposal facilities associated with the Plutonium Finishing Plant: the 216-Z-1A tile field, the 216-Z-9 trench, and the 216-Z-12 crib. Monitoring consisted of spectral gamma-ray logging of 21 boreholes. This work was performed by Pacific Northwest National Laboratory in conjunction with Three Rivers Scientific and Waste management Federal Services, inc. Northwest Operations. These three liquid waste disposal facilities were chosen for monitoring because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford Site vadose zone. The basic question addressed by this logging activity is ``Has the configuration of subsurface contamination changed since it was last measured?`` Previous borehole logging and laboratory analyses provide the baseline data to help answer this question.

  18. Statistical Analysis Of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2012-08-01

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  19. STATISTICAL ANALYSIS OF TANK 5 FLOOR SAMPLE RESULTS

    SciTech Connect

    Shine, E.

    2012-03-14

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, radionuclide, inorganic, and anion concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements above their

  20. Statistical Analysis of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2013-01-31

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide1, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  1. EGRET Observations of the Diffuse Gamma-Ray Emission in Orion: Analysis Through Cycle 6

    NASA Technical Reports Server (NTRS)

    Digel, S. W.; Aprile, E.; Hunter, S. D.; Mukherjee, R.; Xu, F.

    1999-01-01

    We present a study of the high-energy diffuse emission observed toward Orion by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory. The total exposure by EGRET in this region has increased by more than a factor of two since a previous study. A simple model for the diffuse emission adequately fits the data; no significant point sources are detected in the region studied (1 = 195 deg to 220 deg and b = -25 deg to -10 deg) in either the composite dataset or in two separate groups of EGRET viewing periods considered. The gamma-ray emissivity in Orion is found to be (1.65 +/- 0.11) x 10(exp -26)/s.sr for E > 100 MeV, and the differential emissivity is well-described as a combination of contributions from cosmic-ray electrons and protons with approximately the local density. The molecular mass calibrating ratio is N(H2)/W(sub CO) = (1.35 +/- 0.15) x 10(exp 20)/sq cm.(K.km/s).

  2. Analysis of Numerical Simulation Results of LIPS-200 Lifetime Experiments

    NASA Astrophysics Data System (ADS)

    Chen, Juanjuan; Zhang, Tianping; Geng, Hai; Jia, Yanhui; Meng, Wei; Wu, Xianming; Sun, Anbang

    2016-06-01

    Accelerator grid structural and electron backstreaming failures are the most important factors affecting the ion thruster's lifetime. During the thruster's operation, Charge Exchange Xenon (CEX) ions are generated from collisions between plasma and neutral atoms. Those CEX ions grid's barrel and wall frequently, which cause the failures of the grid system. In order to validate whether the 20 cm Lanzhou Ion Propulsion System (LIPS-200) satisfies China's communication satellite platform's application requirement for North-South Station Keeping (NSSK), this study analyzed the measured depth of the pit/groove on the accelerator grid's wall and aperture diameter's variation and estimated the operating lifetime of the ion thruster. Different from the previous method, in this paper, the experimental results after the 5500 h of accumulated operation of the LIPS-200 ion thruster are presented firstly. Then, based on these results, theoretical analysis and numerical calculations were firstly performed to predict the on-orbit lifetime of LIPS-200. The results obtained were more accurate to calculate the reliability and analyze the failure modes of the ion thruster. The results indicated that the predicted lifetime of LIPS-200's was about 13218.1 h which could satisfy the required lifetime requirement of 11000 h very well.

  3. Gamma-ray dosimetry measurements of the Little Boy replica

    SciTech Connect

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We present the current status of our gamma-ray dosimetry results for the Little Boy replica. Both Geiger-Mueller and thermoluminescent detectors were used in the measurements. Future work is needed to test assumptions made in data analysis.

  4. New Applications of Gamma Spectroscopy: Characterization Tools for D&D Process Development, Inventory Reduction Planning & Shipping, Safety Analysis & Facility Management During the Heavy Element Facility Risk Reduction Program

    SciTech Connect

    Mitchell, M; Anderson, B; Gray, L; Vellinger, R; West, M; Gaylord, R; Larson, J; Jones, G; Shingleton, J; Harris, L; Harward, N

    2006-01-23

    Novel applications of gamma ray spectroscopy for D&D process development, inventory reduction, safety analysis and facility management are discussed in this paper. These applications of gamma spectroscopy were developed and implemented during the Risk Reduction Program (RPP) to successfully downgrade the Heavy Element Facility (B251) at Lawrence Livermore National Laboratory (LLNL) from a Category II Nuclear Facility to a Radiological Facility. Non-destructive assay in general, gamma spectroscopy in particular, were found to be important tools in project management, work planning, and work control (''Expect the unexpected and confirm the expected''), minimizing worker dose, and resulted in significant safety improvements and operational efficiencies. Inventory reduction activities utilized gamma spectroscopy to identify and confirm isotopics of legacy inventory, ingrowth of daughter products and the presence of process impurities; quantify inventory; prioritize work activities for project management; and to supply information to satisfy shipper/receiver documentation requirements. D&D activities utilize in-situ gamma spectroscopy to identify and confirm isotopics of legacy contamination; quantify contamination levels and monitor the progress of decontamination efforts; and determine the point of diminishing returns in decontaminating enclosures and glove boxes containing high specific activity isotopes such as {sup 244}Cm and {sup 238}Pu. In-situ gamma spectroscopy provided quantitative comparisons of several decontamination techniques (e.g. TLC-free Stripcoat{trademark}, Radiac{trademark} wash, acid wash, scrubbing) and was used as a part of an iterative process to determine the appropriate level of decontamination and optimal cost to benefit ratio. Facility management followed a formal, rigorous process utilizing an independent, state certified, peer-reviewed gamma spectroscopy program, in conjunction with other characterization techniques, process knowledge, and

  5. Supervised DNA Barcodes species classification: analysis, comparisons and results

    PubMed Central

    2014-01-01

    Background Specific fragments, coming from short portions of DNA (e.g., mitochondrial, nuclear, and plastid sequences), have been defined as DNA Barcode and can be used as markers for organisms of the main life kingdoms. Species classification with DNA Barcode sequences has been proven effective on different organisms. Indeed, specific gene regions have been identified as Barcode: COI in animals, rbcL and matK in plants, and ITS in fungi. The classification problem assigns an unknown specimen to a known species by analyzing its Barcode. This task has to be supported with reliable methods and algorithms. Methods In this work the efficacy of supervised machine learning methods to classify species with DNA Barcode sequences is shown. The Weka software suite, which includes a collection of supervised classification methods, is adopted to address the task of DNA Barcode analysis. Classifier families are tested on synthetic and empirical datasets belonging to the animal, fungus, and plant kingdoms. In particular, the function-based method Support Vector Machines (SVM), the rule-based RIPPER, the decision tree C4.5, and the Naïve Bayes method are considered. Additionally, the classification results are compared with respect to ad-hoc and well-established DNA Barcode classification methods. Results A software that converts the DNA Barcode FASTA sequences to the Weka format is released, to adapt different input formats and to allow the execution of the classification procedure. The analysis of results on synthetic and real datasets shows that SVM and Naïve Bayes outperform on average the other considered classifiers, although they do not provide a human interpretable classification model. Rule-based methods have slightly inferior classification performances, but deliver the species specific positions and nucleotide assignments. On synthetic data the supervised machine learning methods obtain superior classification performances with respect to the traditional DNA Barcode

  6. Skin test and Gamma Interferon enzyme-linked Immunosorbent assay results in Sheep exposed to dead Mycobacterium avium subspecies paratuberculosis Organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cell mediated immunity (CMI) diagnostic tests, such as the gamma interferon enzyme-linked immunosorbent assay (IFN-gamma ELISA) and the johnin skin test, have the potential to detect animals infected with Mycobacterium avium subspecies paratuberculosis (MAP) early in the course of the disease. While...

  7. Radioactive Waste Characterization Strategies; Comparisons Between AK/PK, Dose to Curie Modeling, Gamma Spectroscopy, and Laboratory Analysis Methods- 12194

    SciTech Connect

    Singledecker, Steven J.; Jones, Scotty W.; Dorries, Alison M.; Henckel, George; Gruetzmacher, Kathleen M.

    2012-07-01

    In the coming fiscal years of potentially declining budgets, Department of Energy facilities such as the Los Alamos National Laboratory (LANL) will be looking to reduce the cost of radioactive waste characterization, management, and disposal processes. At the core of this cost reduction process will be choosing the most cost effective, efficient, and accurate methods of radioactive waste characterization. Central to every radioactive waste management program is an effective and accurate waste characterization program. Choosing between methods can determine what is classified as low level radioactive waste (LLRW), transuranic waste (TRU), waste that can be disposed of under an Authorized Release Limit (ARL), industrial waste, and waste that can be disposed of in municipal landfills. The cost benefits of an accurate radioactive waste characterization program cannot be overstated. In addition, inaccurate radioactive waste characterization of radioactive waste can result in the incorrect classification of radioactive waste leading to higher disposal costs, Department of Transportation (DOT) violations, Notice of Violations (NOVs) from Federal and State regulatory agencies, waste rejection from disposal facilities, loss of operational capabilities, and loss of disposal options. Any one of these events could result in the program that mischaracterized the waste losing its ability to perform it primary operational mission. Generators that produce radioactive waste have four characterization strategies at their disposal: - Acceptable Knowledge/Process Knowledge (AK/PK); - Indirect characterization using a software application or other dose to curie methodologies; - Non-Destructive Analysis (NDA) tools such as gamma spectroscopy; - Direct sampling (e.g. grab samples or Surface Contaminated Object smears) and laboratory analytical; Each method has specific advantages and disadvantages. This paper will evaluate each method detailing those advantages and disadvantages

  8. Acoustic analysis in Mudejar-Gothic churches: experimental results.

    PubMed

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. PMID:15957758

  9. Acoustic analysis in Mudejar-Gothic churches: Experimental results

    NASA Astrophysics Data System (ADS)

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. .

  10. Oceanographic results from analysis of ERS-1 altimetry

    NASA Technical Reports Server (NTRS)

    Tapley, B. D.; Shum, C. K.; Chambers, D. P.; Peterson, G. E.; Ries, J. C.

    1994-01-01

    Large scale dynamic ocean topography and its variations were observed using ERS-1 radar altimeter measurements. The altimeter measurements analyzed are primarily from the ESA ocean product (OPR02) and from the Interim Geophysical Data Records (IGDR) generated by NOAA from the fast delivery (FD) data during the ERS-1 35 day repeat orbit phase. The precise orbits used for the dynamic topography solution are computed using dual satellite crossover measurements from ERS-1 and TOPEX (Topology Ocean Experiment)/Poseidon (T/P) as additional tracking data, and using improved models and constants which are consistent with T/P. Analysis of the ERS-1 dynamic topography solution indicates agreement with the T/P solution at the 5 cm root mean square level, with regional differences as large as 15 cm tide gauges at the 8 to 9 cm level. There are differences between the ERS-1 OPR02 and IGDR determined dynamic topography solutions on the order of 5 cm root mean square. Mesoscale oceanic variability time series obtained using collinear analysis of the ERS-1 altimeter data show good qualitative agreement when compared with the T/P results.

  11. {gamma} production at CDF

    SciTech Connect

    Abe, F.

    1995-07-01

    We report on preliminary measurements of the {gamma}(1S), {gamma}(2S) and {gamma}(3S) differential and integrated cross sections in p{bar p} at {radical}s = 1.8 TeV using a sample of 16.6 {+-} 0.6 pb{sup -1} collected by the Collider Detector at Fermilab. The three resonances were reconstructed through the decay {gamma} {yields} {mu}{sup +}{mu}{sup -} in the rapidity region {vert_bar}y{vert_bar} < 0.4. The cross section results are compared to theoretical models of direct bottomonium production.

  12. EPR investigation of some gamma-irradiated excipients

    NASA Astrophysics Data System (ADS)

    Aleksieva, Katerina; Yordanov, Nicola D.

    2012-09-01

    The results of electron paramagnetic resonance (EPR) studies on some excipients: lactose, microcrystalline cellulose (avicel), starch, dioxosilane (aerosil), talc and magnesium stearate before and after gamma-irradiation are reported. Before irradiation, all samples are EPR silent except talc. After gamma-irradiation, they show complex spectra except magnesium stearate, which is EPR silent. Studies show the influence of gamma-irradiation on EPR spectra and stability of gamma-induced radicals. Analysis of the EPR spectrum of gamma-irradiated talc shows that this material is radiation insensitive. Only lactose forms stable-free radicals upon gamma sterilization and can be used for identification of radiation processing for a long time period thereafter.

  13. The geomagnetic storms of 2015: Statistical analysis and forecasting results

    NASA Astrophysics Data System (ADS)

    Paouris, Evangelos; Gerontidou, Maria; Mavromichalaki, Helen

    2016-04-01

    The year 2015 was characterized by long geomagnetic quiet periods with a lot of geomagnetically active breaks although it is on the declining phase of the current solar cycle. As a result a number of geomagnetic storms in the G1 up to G4 scale were noticed. In this work the characteristics of these geomagnetic storms like the scale level, the origin of the storm (CME or CIR) and the duration have been studied. Furthermore, a statistical analysis of these events and a comparative study of the forecasting and the actual geomagnetic conditions are performed using data from the NOAA space weather forecasting center and from the Athens Space Weather Forecasting Center as well. These forecasting centers estimate and provide every day the geomagnetic conditions for the upcoming days giving the values of the geomagnetic index Ap. The forecasting values of Ap index for the year 2015 from these two centers and their comparison in terms of the actual values are discussed.

  14. Disc Motor: Conventional and Superconductor Simulated Results Analysis

    NASA Astrophysics Data System (ADS)

    Inácio, David; Martins, João; Neves, Mário Ventim; Álvarez, Alfredo; Rodrigues, Amadeu Leão

    Taking into consideration the development and integration of electrical machines with lower dimensions and higher performance, this paper presents the design and development of a three-phase axial flux disc motor, with 50 Hz frequency supply. It is made with two conventional semi-stators and a rotor, which can be implemented with a conventional aluminum disc or a high temperature-superconducting disc. The analysis of the motor characteristics is done with a 2D commercial finite elements package, being the modeling performed as a linear motor. The obtained results allow concluding that the superconductor motor provides a higher force than the conventional one. The conventional disc motor presents an asynchronous behavior, like a conventional induction motor, while the superconductor motor presents both synchronous and asynchronous behaviors.

  15. Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011

    SciTech Connect

    2011-12-21

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco site for the LTHMP on May 16 and 17, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method, because the laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

  16. Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2011 at Rulison, Colorado

    SciTech Connect

    2012-05-10

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 18, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method. The laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.

  17. Performance analysis of relay-aided free-space optical communication system over gamma-gamma fading channels with pointing errors

    NASA Astrophysics Data System (ADS)

    Fu, Hui-hua; Wang, Ping; Wang, Ran-ran; Liu, Xiao-xia; Guo, Li-xin; Yang, Yin-tang

    2016-07-01

    The average bit error rate ( ABER) performance of a decode-and-forward (DF) based relay-assisted free-space optical (FSO) communication system over gamma-gamma distribution channels considering the pointing errors is studied. With the help of Meijer's G-function, the probability density function (PDF) and cumulative distribution function (CDF) of the aggregated channel model are derived on the basis of the best path selection scheme. The analytical ABER expression is achieved and the system performance is then investigated with the influence of pointing errors, turbulence strengths and structure parameters. Monte Carlo (MC) simulation is also provided to confirm the analytical ABER expression.

  18. ISS Expeditions 16 & 17: Chemical Analysis Results for Potable Water

    NASA Technical Reports Server (NTRS)

    Straub, John E., II; Plumlee, Debrah K.; Schultz, John R.

    2009-01-01

    During the twelve month span of Expeditions 16 and 17 beginning October of 2007, the chemical quality of the potable water onboard the International Space Station (ISS) was verified safe for crew consumption through the return and chemical analysis of water samples by the Water and Food Analytical Laboratory (WAFAL) at Johnson Space Center (JSC). Reclaimed cabin humidity condensate and Russian ground-supplied water were the principle sources of potable water and for the first time, European groundsupplied water was also available. Although water was transferred from Shuttle to ISS during Expeditions 16 and 17, no Shuttle potable water was consumed during this timeframe. A total of 12 potable water samples were collected using U.S. hardware during Expeditions 16 and 17 and returned on Shuttle flights 1E (STS122), 1JA (STS123), and 1J (STS124). The average sample volume was sufficient for complete chemical characterization to be performed. The results of JSC chemical analyses of these potable water samples are presented in this paper. The WAFAL also received potable water samples for analysis from the Russian side collected inflight with Russian hardware, as well as preflight samples of Rodnik potable water delivered to ISS on Russian Progress vehicles 28 to 30. Analytical results for these additional potable water samples are also reported and discussed herein. Although the potable water supplies available during Expeditions 16 and 17 were judged safe for crew consumption, a recent trending of elevated silver levels in the SVOZV water is a concern for longterm consumption and efforts are being made to lower these levels.

  19. Pulse-shape analysis of Cs 2LiYCl 6:Ce scintillator for neutron and gamma-ray discrimination

    NASA Astrophysics Data System (ADS)

    Lee, D. W.; Stonehill, L. C.; Klimenko, A.; Terry, J. R.; Tornga, S. R.

    2012-02-01

    Cs 2LiYCl 6:Ce (CLYC) is one of the most promising new scintillators for detecting both neutrons and gamma-rays. Its neutron and gamma-ray discrimination capability using pulse-shape analysis has drawn much attention, and there is significant interest in its use in field applications. For such applications, compact and low-power readout electronics capable of exploiting the pulse-shape discrimination (PSD) capabilities of CLYC will be essential. A readout system centered around a PSD-capable application specific integrated circuit (ASIC) that is well-suited for use with CLYC has been characterized, tested, and validated. As part of this study, automated analysis of CLYC data collected with a fast waveform digitizer extracted optimized charge integration windows for PSD. Additionally, several different CLYC samples were studied in order to gain understanding of the dependance of pulse shapes on parameters such as crystal size, 6Li enrichment level, crystal packaging, and choice of PMT. Extremely good PSD performance was obtained from CLYC scintillator and the ASIC-based readout system.

  20. A time-variant processing approach for the analysis of alpha and gamma MEG oscillations during flicker stimulus generated entrainment.

    PubMed

    Wacker, Matthias; Galicki, Miroslav; Putsche, Peter; Milde, Thomas; Schwab, Karin; Haueisen, Jens; Ligges, Carolin; Witte, Herbert

    2011-11-01

    Repetitive flicker stimulation (photic driving) offers the possibility to study the properties and coupling characteristics of stimulation-sensitive neuronal oscillators by means of the MEG/EEG analysis. With flicker frequencies in the region of the individual alpha band frequency, the dynamics of the entrainment process of the alpha oscillation, as well as the dynamics of the accompanying gamma oscillations and the coupling between the oscillations, are investigated by means of an appropriate combination of time-variant analysis methods. The Hilbert and the Gabor transformation reveal time-variant properties (frequency entrainment, phase locking, and n:m synchronization) of the entrainment process in the whole frequency range. Additionally, time-variant partial directed coherence is applied to identify ocular saccadic interferences and to study the directed information transfer between the recording sites of the simultaneously derived MEG/EEG data during the entrainment. The MEG data is the focus of this methodological study as the entrainment effects of the alpha oscillation are stronger in MEG than in the EEG. The occipital brain region (visual cortex) was mainly investigated and the dynamics of the alpha entrainment quantified. It can be shown that at the beginning of this entrainment, a transient, strongly phase-locked "40-Hz" gamma oscillation occurs. PMID:21712153

  1. Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. IV. Results of the 2014 Follow-up Campaign

    NASA Astrophysics Data System (ADS)

    Ricci, F.; Massaro, F.; Landoni, M.; D'Abrusco, R.; Milisavljevic, D.; Stern, D.; Masetti, N.; Paggi, A.; Smith, Howard A.; Tosti, G.

    2015-05-01

    The extragalactic γ-ray sky is dominated by the emission arising from blazars, one of the most peculiar classes of radio-loud active galaxies. Since the launch of Fermi several methods were developed to search for blazars as potential counterparts of unidentified γ-ray sources (UGSs). To confirm the nature of the selected candidates, optical spectroscopic observations are necessary. In 2013 we started a spectroscopic campaign to investigate γ-ray blazar candidates selected according to different procedures. The main goals of our campaign are: (1) to confirm the nature of these candidates, and (2) whenever possible, determine their redshifts. Optical spectroscopic observations will also permit us to verify the robustness of the proposed associations and check for the presence of possible source class contaminants to our counterpart selection. This paper reports the results of observations carried out in 2014 in the northern hemisphere with Kitt Peak National Observatory and in the southern hemisphere with the Southern Astrophysical Research telescopes. We also report three sources observed with the Magellan and Palomar telescopes. Our selection of blazar-like sources that could be potential counterparts of UGSs is based on their peculiar infrared colors and on their combination with radio observations both at high and low frequencies (i.e., above and below ˜1 GHz) in publicly available large radio surveys. We present the optical spectra of 27 objects. We confirm the blazar-like nature of nine sources that appear to be potential low-energy counterparts of UGSs. Then we present new spectroscopic observations of 10 active galaxies of uncertain type associated with Fermi sources, classifying all of them as blazars. In addition, we present the spectra for five known γ-ray blazars with uncertain redshift estimates and three BL Lac candidates that were observed during our campaign. We also report the case for WISE J173052.85-035247.2, candidate counterpart of the

  2. Results from Action Analysis in an Interactive Learning Environment

    ERIC Educational Resources Information Center

    Scheuer, Oliver; Muhlenbrock, Martin; Melis, Erica

    2007-01-01

    Recently, there is a growing interest in the automatic analysis of learner activity in web-based learning environments. The approach and system SIAM (System for Interaction Analysis by Machine learning) presented in this article aims at helping to establish a basis for the automatic analysis of interaction data by developing a data logging and…

  3. Nuclear chemistry of returned lunar samples: Nuclide analysis by gamma-ray spectrometry

    NASA Technical Reports Server (NTRS)

    Okelley, G. D.

    1975-01-01

    Primordial and cosmogenic radionuclide concentrations are determined nondestructively by gamma-ray spectrometry in soil and rock samples from the returned Apollo 17 sample collection from Taurus-Littrow and Descartes. Geochemical evidence in support of field geology speculation concerning layering of the subfloor basalt flows is demonstrated along with a possible correlation of magmatic fractionation of K/U as a function of depth. The pattern of radionuclide concentrations observed in these samples is distinct due to proton bombardment by the intense solar flares of August 4-9, 1972. Such radionuclide determinations are used in determining lunar sample orientation and characterizing solar flare activity.

  4. The effect of gamma-ray transport on afterheat calculations for accident analysis

    SciTech Connect

    Reyes, S.; Latkowski, J.F.; Sanz, J.

    2000-05-01

    Radioactive afterheat is an important source term for the release of radionuclides in fusion systems under accident conditions. Heat transfer calculations are used to determine time-temperature histories in regions of interest, but the true source term needs to be the effective afterheat, which considers the transport of penetrating gamma rays. Without consideration of photon transport, accident temperatures may be overestimated in others. The importance of this effect is demonstrated for a simple, one-dimensional problem. The significance of this effect depends strongly on the accident scenario being analyzed.

  5. Digital Architecture – Results From a Gap Analysis

    SciTech Connect

    Oxstrand, Johanna Helene; Thomas, Kenneth David; Fitzgerald, Kirk

    2015-09-01

    The digital architecture is defined as a collection of IT capabilities needed to support and integrate a wide-spectrum of real-time digital capabilities for nuclear power plant performance improvements. The digital architecture can be thought of as an integration of the separate I&C and information systems already in place in NPPs, brought together for the purpose of creating new levels of automation in NPP work activities. In some cases, it might be an extension of the current communication systems, to provide digital communications where they are currently analog only. This collection of IT capabilities must in turn be based on a set of user requirements that must be supported for the interconnected technologies to operate in an integrated manner. These requirements, simply put, are a statement of what sorts of digital work functions will be exercised in a fully-implemented seamless digital environment and how much they will be used. The goal of the digital architecture research is to develop a methodology for mapping nuclear power plant operational and support activities into the digital architecture, which includes the development of a consensus model for advanced information and control architecture. The consensus model should be developed at a level of detail that is useful to the industry. In other words, not so detailed that it specifies specific protocols and not so vague that it is only provides a high level description of technology. The next step towards the model development is to determine the current state of digital architecture at typical NPPs. To investigate the current state, the researchers conducted a gap analysis to determine to what extent the NPPs can support the future digital technology environment with their existing I&C and IT structure, and where gaps exist with respect to the full deployment of technology over time. The methodology, result, and conclusions from the gap analysis are described in this report.

  6. Accuracy of the interferon-gamma release assay for the diagnosis of tuberculous pleurisy: an updated meta-analysis

    PubMed Central

    Zhu, Jing; Feng, Mei; Wan, Chun

    2015-01-01

    Background and Objectives. The best method for diagnosing tuberculous pleurisy (TP) remains controversial. Since a growing number of publications focus on the interferon-gamma release assay (IGRA), we meta-analyzed the available evidence on the overall diagnostic performance of IGRA applied to pleural fluid and peripheral blood. Materials and Methods. PubMed and Embase were searched for relevant English papers up to October 31, 2014. Statistical analyses were performed using Stata and Meta-DiSc. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV), negative predictive value (NPV) and diagnostic odds ratio (DOR) were count. Summary receiver operating characteristic curves and area under the curve (AUC) were used to summarize the overall diagnostic performance. Results. Fifteen publications met our inclusion criteria and were included in the meta analysis. The following pooled estimates for diagnostic parameters of pleural IGRA were obtained: sensitivity, 0.82 (95% CI [0.79–0.85]); specificity, 0.87 (95% CI [0.84–0.90]); PLR, 4.94 (95% CI [2.60–9.39]); NLR, 0.22 (95% CI [0.13–0.38]); PPV, 0.91 (95% CI [0.85–0.96]); NPV, 0.79 (95% CI [0.71–0.85]); DOR, 28.37 (95% CI [10.53–76.40]); and AUC, 0.91. The corresponding estimates for blood IGRA were as follows: sensitivity, 0.80 (95% CI [0.76–0.83]); specificity, 0.70 (95% CI [0.65–0.75]); PLR, 2.48 (95% CI [1.95–3.17]); NLR, 0.30 (95% CI [0.24–0.37]); PPV, 0.79 (95% CI [0.60–0.87]); NPV, 0.75 (95% CI [0.62–0.83]); DOR, 9.96 (95% CI [6.02–16.48]); and AUC, 0.89. Conclusions. This meta analysis suggested that pleural IGRA has potential for serving as a complementary method for diagnosing TP; however, its cost, high turn around time, and sub-optimal performance make it unsuitable as a stand-alone diagnostic tool. Better tests for the diagnosis of TP are required. PMID:26038718

  7. Statistical Analysis of the Long Baseline Variability Properties of a Large Gamma-Ray Selected Blazar AGN Sample

    NASA Astrophysics Data System (ADS)

    Shrader, Chris R.

    2013-06-01

    The Fermi Gamma-Ray Space Telescope has cataloged over 1800 gamma-ray (>100 MeV) point sources of which more than 1100 are identified with AGN. These AGN, and a large number of unidentified high-latitude objects of which a large fraction are also likely AGN, are predominantly representative of the radio-loud “blazar” subclass. The emission from these objects is well known to be beaming dominated and is almost always variable, often exhibiting high-amplitude flaring. To date there have been numerous studies of individual objects including multi-wavelength campaigns in some cases including parsec-scale radio jet morphological study. Collectively, this has led to new insight in to our understanding of the blazar phenomena and jet propagation in general. However, there remains a dearth of information on the collective variability characteristics of the population as a statistical ensemble. What, for example, are the distributions of flare amplitudes, durations, temporal profiles and recurrence histories among the gamma-ray blazar subclasses? Given the unprecedented sky coverage of Fermi - the full sky is observed approximately every two orbits leading to an approximate one part in 6 monitoring duty cycle for any point on the sky - we have begun to explore this issue. A light curve database compiled and maintained (weekly) by the Fermi Science Support Center contains flux histories for every source in the Fermi 2FGL catalog. In this contribution, we present our analysis of the statistical properties of the high-latitude component of this light curve database.

  8. Measurement of gamma in B-+ to D(*) K-+ and B-+ to D K*-+ Decays with a Dalitz Analysis of D to Ks pi- pi+

    SciTech Connect

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /Pisa, Scuola Normale Superiore /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Vanderbilt U. /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.

    2005-08-04

    We present a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase {gamma} with a Dalitz plot analysis of neutral D-meson decays to the K{sub S}{sup 0} {pi}{sup -}{pi}{sup +} final state from B{sup {-+}} {yields} D{sup (*)}K{sup {-+}} and B{sup {-+}} {yields} DK*{sup {-+}} decays, using a sample of 227 million B{bar B} pairs collected by the BABAR detector. We measure {gamma} = (67 {+-} 28 {+-} 13 {+-} 11){sup o}, where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the Dalitz model uncertainty. This result suffers from a two-fold ambiguity. The contribution to the Dalitz model uncertainty due to the description of the {pi}{pi} S-wave in D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup -}{pi}{sup +}, evaluated using a K-matrix formalism, is found to be 3{sup o}.

  9. Measurement of the Cabibbo-Kobayashi-Maskawa angle gamma in B+/--->D*K+/- decays with a Dalitz analysis of D-->K0(S)pi-pi+.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Klose, V; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Petersen, T C; Pierini, M; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Li, X; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pacetti, S; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Graziani, G; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Suzuki, K; Thompson, J M; Va'vra, J; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-09-16

    We report on a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase gamma through a Dalitz analysis of neutral D decays to K0(S)pi-pi+ in the processes B+/- -->D*K+/-, D*-->Dpi0, Dgamma. Using a sample of 227 x 10(6) BB pairs collected by the BABAR detector, we measure the amplitude ratios r(B)=0.12+/-0.03+/-0.04 and r*(B)=0.17+/-0.10+/-0.03+/-0.03, the relative strong phases delta(B)=(104+/-45(+17+16)(-21-24))degrees and delta*(B)=(-64+/-41(+14)(-12)+/-15) degrees between the amplitudes A(B- -->D*0K-) and A(B- -->D*0)K-), and gamma=(70+/-31(+12+14)(-10-11))degrees. The first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the Dalitz model uncertainty. The results for the strong and weak phases have a twofold ambiguity. PMID:16197065

  10. Plutonium Mobility Studies: 216-Z-9 Trench Sample Analysis Results

    SciTech Connect

    Cantrell, Kirk J.; Geiszler, Keith N.; Arey, Bruce W.

    2008-09-05

    A variety of analyses were conducted on selected sediment samples collected from two wells (299 W15-46 and 299-W15-48) drilled near the 216-Z-9 Trench to elucidate the form and potential for Pu and Am to be mobilized under present conditions and those that could be expected in future remediation scenarios. Analyses included moisture content, determination of the less than sand size fraction (silt plus clay), carbon analysis, SEM/EDS analysis, microwave-assisted acid digestions for total element analysis, and extraction tests using Hanford groundwater as the leachate. Results of the extraction tests were used as input to conduct equilibrium geochemical modeling of the solutions with Geochemist’s Workbench®. Geochemical modeling results for Pu were evaluated in terms of recent conclusions regarding the solubility and redox reactions of Pu by Neck et al. (2007a, 2007b). It was found that the highest concentrations of Pu and Am were associated with sediments of low silt/clay content and occur above silt/clay rich layers within the sediment profile. It was also found that the Pu and Am were relatively enriched in the silt/clay portion of these samples. The fact that the highest concentrations of Pu and Am occurred in sediments with low silt/clay contents suggests that waste solutions had perched on top of the low permeability silt/clay rich layers and interactions with the high silt/clay layers was minimal. SEM/EDS analysis indicated that the Pu and Am in these sediments does not occur as discrete micron size particles, and therefore must occur as mononuclear or polynuclear/ nanoclusters size particles adsorbed throughout the sediment samples. Leaching of these samples with Hanford groundwater indicates that release of Pu and Am from the sediments is correlated most significantly with the acidity of the water and not the initial concentrations of Pu and Am in the sediments. Only extracts that were acidic after contact with the sediments (pH 4.3 to 5.4) contained

  11. Gamma spectroscopic analysis and associated radiation hazards of building materials used in Egypt.

    PubMed

    El-Taher, A

    2010-02-01

    Radiation exposure of the population can be increased appreciably by the use of building materials containing above-normal levels of naturally occurring radionuclides of terrestrial origin. Using gamma-ray spectrometry, the natural radioactivity levels of 55 samples of natural and manufactured Egyptian building materials have been investigated. The samples were collected from local market and construction sites. From the measured gamma-ray spectra, activity concentrations were determined. The activities were in the ranges 11.7-35.6, 12.4-55.2 and 60-350 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The activities are compared with available reported data from other countries and with the world average value for soils. The radium equivalent activity Ra(eq), the external hazard index H(ex) and the absorbed dose rate in air D in each sample was evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. All building materials have shown Ra(eq) (range from 37.76 to 116.87 Bq kg(-1)) lower than the limit of 370 Bq kg(-1) adopted by the Organization for Economic Cooperation and Development (OECD). The absorbed dose rate in indoor air is lower than the international recommended value of 55 nGy h(-1) for all test samples. All the materials examined are acceptable for use as building materials as defined by the OECD criterion. PMID:19841012

  12. An Alternative View of the Dynamical Origin of the P11 Nucleon Resonances: Results from the Excited Baryon Analysis Center

    SciTech Connect

    Hiroyuki Kamano

    2012-04-01

    We present an alternative interpretation for the dynamical origin of the P{sub 11} nucleon resonances, which results from the dynamical coupled-channels analysis at Excited Baryon Analysis Center of Jefferson Lab. The results indicate the crucial role of the multichannel reaction dynamics in determining the N* spectrum. An understanding of the spectrum and structure of the excited nucleon (N*) states is a fundamental challenge in the hadron physics. The N* states, however, couple strongly to the meson-baryon continuum states and appear only as resonance states in the {gamma}N and {pi}N reactions. One can expect from such strong couplings that the (multichannel) reaction dynamics will affect significantly the N* states and cannot be neglected in extracting the N* parameters from the data and giving physical interpretations. It is thus well recognized nowadays that a comprehensive study of all relevant meson production reactions with {pi}N,{eta}N,{pi}{pi}N,KY, {hor_ellipsis} final states is necessary for a reliable extraction of the N* parameters. To address this challenging issue, the Excited Baryon Analysis Center (EBAC) of Jefferson Lab has been conducting the comprehensive analysis of the world data of {gamma}N,{pi}N {yields} {pi}N,{eta}N,{pi}{pi}N,KY, {hor_ellipsis} reactions systematically, covering the wide energy and kinematic regions. The analysis is pursued with a dynamical coupled-channels (DCC) model, the EBAC-DCC model, within which the unitarity among relevant meson-baryon channels, including the three-body {pi}{pi}N channel, is fully taken into account.

  13. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer E.; Aitchison, Lindsay

    2009-01-01

    A space suit s mobility is critical to an astronaut s ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. The term mobility, with respect to space suits, is defined in terms of two key components: joint range of motion and joint torque. Individually these measures describe the path which in which a joint travels and the force required to move it through that path. Previous space suits mobility requirements were defined as the collective result of these two measures and verified by the completion of discrete functional tasks. While a valid way to impose mobility requirements, such a method does necessitate a solid understanding of the operational scenarios in which the final suit will be performing. Because the Constellation space suit system requirements are being finalized with a relatively immature concept of operations, the Space Suit Element team elected to define mobility in terms of its constituent parts to increase the likelihood that the future pressure garment will be mobile enough to enable a broad scope of undefined exploration activities. The range of motion requirements were defined by measuring the ranges of motion test subjects achieved while performing a series of joint maximizing tasks in a variety of flight and prototype space suits. The definition of joint torque requirements has proved more elusive. NASA evaluated several different approaches to the problem before deciding to generate requirements based on unmanned joint torque evaluations of six different space suit configurations being articulated through 16 separate joint movements. This paper discusses the experiment design, data analysis and results, and the process used to determine the final values for the Constellation pressure garment joint torque requirements.

  14. Advanced Thermal Simulator Testing: Thermal Analysis and Test Results

    SciTech Connect

    Bragg-Sitton, Shannon M.; Dickens, Ricky; Dixon, David; Reid, Robert; Adams, Mike; Davis, Joe

    2008-01-21

    Work at the NASA Marshall Space Flight Center seeks to develop high fidelity, electrically heated thermal simulators that represent fuel elements in a nuclear reactor design to support non-nuclear testing applicable to the potential development of a space nuclear power or propulsion system. Comparison between the fuel pins and thermal simulators is made at the outer fuel clad surface, which corresponds to the outer sheath surface in the thermal simulator. The thermal simulators that are currently being tested correspond to a liquid metal cooled reactor design that could be applied for Lunar surface power. These simulators are designed to meet the geometric and power requirements of a proposed surface power reactor design, accommodate testing of various axial power profiles, and incorporate imbedded instrumentation. This paper reports the results of thermal simulator analysis and testing in a bare element configuration, which does not incorporate active heat removal, and testing in a water-cooled calorimeter designed to mimic the heat removal that would be experienced in a reactor core.

  15. Advanced Thermal Simulator Testing: Thermal Analysis and Test Results

    NASA Technical Reports Server (NTRS)

    Bragg-Sitton, Shannon M.; Dickens, Ricky; Dixon, David; Reid, Robert; Adams, Mike; Davis, Joe

    2008-01-01

    Work at the NASA Marshall Space Flight Center seeks to develop high fidelity, electrically heated thermal simulators that represent fuel elements in a nuclear reactor design to support non-nuclear testing applicable to the development of a space nuclear power or propulsion system. Comparison between the fuel pins and thermal simulators is made at the outer fuel clad surface, which corresponds to the outer sheath surface in the thermal simulator. The thermal simulators that are currently being tested correspond to a SNAP derivative reactor design that could be applied for Lunar surface power. These simulators are designed to meet the geometric and power requirements of a proposed surface power reactor design, accommodate testing of various axial power profiles, and incorporate imbedded instrumentation. This paper reports the results of thermal simulator analysis and testing in a bare element configuration, which does not incorporate active heat removal, and testing in a water-cooled calorimeter designed to mimic the heat removal that would be experienced in a reactor core.

  16. Results and Analysis from Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Matty, Jennifer

    2010-01-01

    A space suit's mobility is critical to an astronaut's ability to perform work efficiently. As mobility increases, the astronaut can perform tasks for longer durations with less fatigue. Mobility can be broken down into two parts: range of motion (ROM) and torque. These two measurements describe how the suit moves and how much force it takes to move. Two methods were chosen to define mobility requirements for the Constellation Space Suit Element (CSSE). One method focuses on range of motion and the second method centers on joint torque. A joint torque test was conducted to determine a baseline for current advanced space suit joint torques. This test utilized the following space suits: Extravehicular Mobility Unit (EMU), Advanced Crew Escape Suit (ACES), I-Suit, D-Suit, Enhanced Mobility (EM)- ACES, and Mark III (MK-III). Data was collected data from 16 different joint movements of each suit. The results were then reviewed and CSSE joint torque requirement values were selected. The focus of this paper is to discuss trends observed during data analysis.

  17. IUS guidance algorithm gamma guide assessment

    NASA Technical Reports Server (NTRS)

    Bray, R. E.; Dauro, V. A.

    1980-01-01

    The Gamma Guidance Algorithm which controls the inertial upper stage is described. The results of an independent assessment of the algorithm's performance in satisfying the NASA missions' targeting objectives are presented. The results of a launch window analysis for a Galileo mission, and suggested improvements are included.

  18. Age depth-model based on cyclostratigraphic analysis of gamma ray data for the past 675 ka in Lake Ohrid (Macedonia/Albania)

    NASA Astrophysics Data System (ADS)

    Baumgarten, Henrike; Wonik, Thomas; Francke, Alexander; Wagner, Bernd; Zanchetta, Giovanni

    2015-04-01

    Lake Ohrid is located at the border between Macedonia and Albania (40°70' N, 20°42 E) and is assumed as the oldest lake in Europe. The lake with a surface area of 360 km² has trapped sediments and volcanic ashes over more than 1.5 Ma and hence, contains essential information of major climatic and environmental change of the central northern Mediterranean region. Seismic investigations indicate a sediment fill of the lake basin up to a thickness of 700 m. In the frame of the ICDP project SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid), several scientific questions are addressed: age and origin of the lake, paleoclimatic change during the Quaternary, tephrostratigraphy, and driving forces for the outstanding biodiversity. The "Deep site" is located in the central deep basin of Lake Ohrid and was targeted for drilling operation to a depth of 569 m below lake floor (mblf) in spring 2013. First results revealed that the bottom part (below 430 mblf) is characterized by coarser grained deposits while the upper part yields fine grained pelagic sediments. High-quality continuous downhole logging data have been achieved by the use of the following tools: spectral gamma ray, magnetic susceptibility, resistivity, dipmeter, borehole televiewer and sonic. The borehole logging data shows strong contrasts in all physical properties, in particular in spectral gamma ray, magnetic susceptibility, resistivity and seismic velocity (vp). Strong cyclicity is evident in Lake Ohrid's pelagic sediment facies, whereas the signal is most pronounced in the total gamma ray and potassium content. The data shows high correlation (R² = 0.75) with the global climate reference curve from benthic foraminifera (LRO4 stack) and undisturbed and continuous sedimentation was preserved. Low potassium (and gamma ray) correlates with interglacial periods and therefore glacial-interglacial dynamics can be read from these data easily. To further investigate the cyclic

  19. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  20. Analysis of T cells bearing different isotypic forms of the gamma/delta T cell receptor in patients with systemic autoimmune diseases.

    PubMed

    Gerli, R; Agea, E; Bertotto, A; Tognellini, R; Flenghi, L; Spinozzi, F; Velardi, A; Grignani, F

    1991-10-01

    The expression of gamma/delta T cell receptor (TCR) on peripheral blood CD3+ cells circulating in 74 patients with different systemic autoimmune diseases was evaluated. There was a significant increase in the gamma/delta T cell number only in patients with primary Sjögren's syndrome (SS) and in untreated patients with systemic lupus erythematosus (SLE). Unlike healthy subjects, a subgroup of patients with SLE and SS displayed a marked increase in gamma/delta T cells. Immunosuppressive treatment of patients with active SLE led to a normalization of the gamma/delta T cell number. Analysis of surface phenotype showed that when patient gamma/delta T cells were expanded in the peripheral blood, they were not activated but bore "memory" markers. In addition, they preferentially expressed the disulfide linked form of the TCR, except in progressive systemic sclerosis where the nondisulfide form was displayed. Serial determinations in single patients demonstrated that the gamma/delta T cell increase is a persistent immunological feature in these patient subgroups. PMID:1837314