Science.gov

Sample records for neutron personnel monitoring

  1. Personnel neutron monitoring in space

    NASA Technical Reports Server (NTRS)

    Schaefer, H. J.

    1978-01-01

    A brief review is presented of available information on the galactic neutron spectrum. An examination is made of the difficulties encountered in the determination of the dose equivalent of neutron recoil protons in the presence of a substantially larger background of trapped and star-produced protons as well as other ionizing particles in space.

  2. Neutron personnel dosimetry

    SciTech Connect

    Griffith, R.V.

    1981-06-16

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments. (ACR)

  3. PERSONNEL NEUTRON DOSIMETER

    DOEpatents

    Fitzgerald, J.J.; Detwiler, C.G. Jr.

    1960-05-24

    A description is given of a personnel neutron dosimeter capable of indicating the complete spectrum of the neutron dose received as well as the dose for each neutron energy range therein. The device consists of three sets of indium foils supported in an aluminum case. The first set consists of three foils of indium, the second set consists of a similar set of indium foils sandwiched between layers of cadmium, whereas the third set is similar to the second set but is sandwiched between layers of polyethylene. By analysis of all the foils the neutron spectrum and the total dose from neutrons of all energy levels can be ascertained.

  4. Personnel electronic neutron dosimeter

    DOEpatents

    Falk, R.B.; Tyree, W.H.

    1982-03-03

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  5. Personnel electronic neutron dosimeter

    DOEpatents

    Falk, Roger B.; Tyree, William H.

    1984-12-18

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  6. Advances in personnel neutron dosimetry

    SciTech Connect

    Vallario, E.; Faust, L.

    1983-07-01

    A program to assess current personnel neutron dosimeter capabilities and to develop improved personnel neutron dosimeters examines the two types of passive dosimeters in use at DOE facilities: NTA film and TLD-albedo dosimeters. Two new neutron dosimeters under development to overcome some of their problems are combination/track-etch dosimeters and pocket rem-meters. The DOE program is investigating new materials and improved manufacturing processes using the CR-39 polymer and that is nearly free of surface defects. 1 figure.

  7. Personnel neutron dose assessment upgrade: Volume 1, Personnel neutron dosimetry assessment: (Final report)

    SciTech Connect

    Hadlock, D.E.; Brackenbush, L.W.; Griffith, R.V.; Hankins, D.E.; Parkhurst, M.A.; Stroud, C.M.; Faust, L.G.; Vallario, E.J.

    1988-07-01

    This report provides guidance on the characteristics, use, and calibration criteria for personnel neutron dosimeters. The report is applicable for neutrons with energies ranging from thermal to less than 20 MeV. Background for general neutron dosimetry requirements is provided, as is relevant federal regulations and other standards. The characteristics of personnel neutron dosimeters are discussed, with particular attention paid to passive neutron dosimetry systems. Two of the systems discussed are used at DOE and DOE-contractor facilities (nuclear track emulsion and thermoluminescent-albedo) and another (the combination TLD/TED) was recently developed. Topics discussed in the field applications of these dosimeters include their theory of operation, their processing, readout, and interpretation, and their advantages and disadvantages for field use. The procedures required for occupational neutron dosimetry are discussed, including radiation monitoring and the wearing of dosimeters, their exchange periods, dose equivalent evaluations, and the documenting of neutron exposures. The coverage of dosimeter testing, maintenance, and calibration includes guidance on the selection of calibration sources, the effects of irradiation geometries, lower limits of detectability, fading, frequency of calibration, spectrometry, and quality control. 49 refs., 6 figs., 8 tabs.

  8. Advances in personnel neutron dosimetry: part 2

    SciTech Connect

    Vallario, E.; Faust, L.

    1983-08-01

    A continuation of the advances in personnel neutron dosimetry research programs and technology transfer reviews work on active dosimeters, electronic devices that determine the dose equivalent to a worker during an exposure to neutron radiation. Active dosemeters are routinely used for gamma radiation dosimetry. Experience with neutron-sensitive pocket rem-meters at several DOE laboratories covers three prototypes. Pocket rem-meters work well for detecting neutrons over a wide energy range. They give instantaneous readout of the accumulated neutron dose-equivalent. 1 figure.

  9. Advances in personnel neutron dosimetry: part 3

    SciTech Connect

    Vallario, E.J.; Faust, L.G.

    1983-09-01

    DOE-sponsored evaluation and upgrading of personnel neutron dosimetry includes a review of new devices involving unique concepts: resonance ionization spectroscopy and organic semiconductor detectors. Resonance ionization spectroscopy uses a laser to detect atoms released by neutron interactions, while organic semiconductors contain large amounts of hydrogen. Although these and other research and evaluation projects reviewed in the first two articles appear promising, there is much more research needed, such as finding a chemically stable organic semiconductor that will be suitable.

  10. Intercomparison of high energy neutron personnel dosimeters

    SciTech Connect

    McDonald, J.C.; Akabani, G.; Loesch, R.M.

    1993-03-01

    An intercomparison of high-energy neutron personnel dosimeters was performed to evaluate the uniformity of the response characteristics of typical neutron dosimeters presently in use at US Department of Energy (DOE) accelerator facilities. It was necessary to perform an intercomparison because there are no national or international standards for high-energy neutron dosimetry. The testing that is presently under way for the Department of Energy Laboratory Accreditation Program (DOELAP) is limited to the use of neutron sources that range in energy from about 1 keV to 2 MeV. Therefore, the high-energy neutron dosimeters presently in use at DOE accelerator facilities are not being tested effectively. This intercomparison employed neutrons produced by the {sup 9}Be(p,n){sup 9}B interaction at the University of Washington cyclotron, using 50-MeV protons. The resulting neutron energy spectrum extended to a maximum of approximately 50-MeV, with a mean energy of about 20-MeV. Intercomparison results for currently used dosimeters, including Nuclear Type A (NTA) film, thermoluminescent dosimeter (TLD)-albedo, and track-etch dosimeters (TEDs), indicated a wide variation in response to identical doses of high-energy neutrons. Results of this study will be discussed along with a description of plans for future work.

  11. Personnel neutron dosimetry at Department of Energy facilities

    SciTech Connect

    Brackenbush, L.W.; Endres, G.W.R.; Selby, J.M.; Vallario, E.J.

    1980-08-01

    This study assesses the state of personnel neutron dosimetry at DOE facilities. A survey of the personnel dosimetry systems in use at major DOE facilities was conducted, a literature search was made to determine recent advances in neutron dosimetry, and several dosimetry experts were interviewed. It was concluded that personnel neutron dosimeters do not meet current needs and that serious problems exist now and will increase in the future if neutron quality factors are increased and/or dose limits are lowered.

  12. 1983 ORNL intercomparison of personnel neutron and gamma dosemeters

    SciTech Connect

    Swaja, R.E.; Sims, C.S.; Greene, R.T.

    1985-01-01

    The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables.

  13. Eleventh DOE workshop on personnel neutron dosimetry

    SciTech Connect

    Not Available

    1991-12-31

    Since its formation, the Office of Health (EH-40) has stressed the importance of the exchange of information related to and improvements in neutron dosimetry. This Workshop was the eleventh in the series sponsored by the Department of Energy (DOE). It provided a forum for operational personnel at DOE facilities to discuss current issues related to neutron dosimetry and for leading investigators in the field to discuss promising approaches for future research. A total of 26 papers were presented including the keynote address by Dr. Warren K. Sinclair, who spoke on, ``The 1990 Recommendations of the ICRP and their Biological Background.`` The first several papers discussed difficulties in measuring neutrons of different energies and ways of compensating or deriving correction factors at individual facilities. Presentations were also given by the US Navy and Air Force. Current research in neutron dosimeter development was the subject of the largest number of papers. These included a number on the development of neutron spectrometers. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  14. Response characteristics of selected personnel neutron dosimeters

    SciTech Connect

    McDonald, J.C.; Fix, J.J.; Hadley, R.T.; Holbrook, K.L.; Yoder, R.C.; Roberson, P.L.; Endres, G.W.R.; Nichols, L.L.; Schwartz, R.B.

    1983-09-01

    Performance characteristics of selected personnel neutron dosimeters in current use at Department of Energy (DOE) facilities were determined from their evaluation of neutron dose equivalent received after irradiations with specific neutron sources at either the National Bureau of Standards (NBS) or the Pacific Northwest Laboratory (PNL). The characteristics assessed included: lower detection level, energy response, precision and accuracy. It was found that when all of the laboratories employed a common set of calibrations, the overall accuracy was approximately +-20%, which is within uncertainty expected for these dosimeters. For doses above 80 mrem, the accuracy improved to better than 10% when a common calibration was used. Individual differences found in this study may reflect differences in calibration technique rather than differences in the dose rates of actual calibration standards. Second, at dose rates above 100 mrem, the precision for the best participants was generally below +-10% which is also within expected limits for these types of dosimeters. The poorest results had a standard deviation of about +-25%. At the lowest doses, which were sometimes below the lower detection limit, the precision often approached or exceeded +-100%. Third, the lower level of detection for free field /sup 252/Cf neutrons generally ranged between 20 and 50 mrem. Fourth, the energy dependence study provided a characterization of the response of the dosimeters to neutron energies far from the calibration energy. 11 references, 22 figures, 26 tables.

  15. 10 CFR 39.65 - Personnel monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Personnel monitoring. 39.65 Section 39.65 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Radiation Safety Requirements § 39.65 Personnel monitoring. (a) The licensee may not permit an individual to act as a...

  16. 10 CFR 39.65 - Personnel monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Personnel monitoring. 39.65 Section 39.65 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Radiation Safety Requirements § 39.65 Personnel monitoring. (a) The licensee may not permit an individual to act as a...

  17. 10 CFR 39.65 - Personnel monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Personnel monitoring. 39.65 Section 39.65 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Radiation Safety Requirements § 39.65 Personnel monitoring. (a) The licensee may not permit an individual to act as a...

  18. 10 CFR 39.65 - Personnel monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Personnel monitoring. 39.65 Section 39.65 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Radiation Safety Requirements § 39.65 Personnel monitoring. (a) The licensee may not permit an individual to act as a...

  19. 10 CFR 39.65 - Personnel monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Personnel monitoring. 39.65 Section 39.65 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Radiation Safety Requirements § 39.65 Personnel monitoring. (a) The licensee may not permit an individual to act as a...

  20. Neutron personnel dosimetry intercomparison studies at the Oak Ridge National Laboratory: a summary (1981-1986).

    PubMed

    Swaja, R E; Sims, C S

    1988-09-01

    To provide an opportunity for dosimetrists to test and calibrate their neutron personnel monitoring systems, the staff of the Dosimetry Applications Research (DOSAR) Facility at the Oak Ridge National Laboratory (ORNL) has conducted personnel dosimetry intercomparison studies (PDIS) periodically since 1974. During these studies, personnel dosimeters are mailed to ORNL, exposed to low-level (less than 15 mSv) neutron dose equivalents in a variety of mixed-radiation fields, and then returned to the participants for evaluation. These intercomparisons have provided more data on neutron dosimeter performance than any other periodic test program conducted to date. This report presents a summary and analysis of about 3450 neutron dose equivalent measurements reported for PDIS 7 through 12 (1981-1986) with emphasis on low dose equivalent sensitivity, accuracy and precision, and performance relative to accreditation standards for the basic types of personnel dosimetry systems. Relationships of the PDIS results to occupational neutron monitoring, accreditation testing, and methods to improve personnel neutron dosimetry performance are also discussed.

  1. 10 CFR 36.55 - Personnel monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators... requirements of this paragraph, a check of their response to radiation must be done at least...

  2. 10 CFR 36.55 - Personnel monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators... requirements of this paragraph, a check of their response to radiation must be done at least...

  3. 10 CFR 36.55 - Personnel monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators... requirements of this paragraph, a check of their response to radiation must be done at least...

  4. 10 CFR 36.55 - Personnel monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators... requirements of this paragraph, a check of their response to radiation must be done at least...

  5. 10 CFR 36.55 - Personnel monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators... requirements of this paragraph, a check of their response to radiation must be done at least...

  6. Neutron monitoring: Past, present, future

    NASA Astrophysics Data System (ADS)

    Bieber, John William

    2013-02-01

    Ground-based detectors were instrumental in establishing the nature of cosmic rays in the early days of the field, and they continue to provide invaluable information now and for the foreseeable future. This article begins with homage to Scott Forbush and the fundamental discoveries he made with the Carnegie Institution ionization chambers in the 1930s and 1940s. Circa 1950 John Simpson invented the neutron monitor, an instrument more capable, sensitive, and stable than the ionization chamber. An early landmark of the neutron monitor era was the famous 1956 solar cosmic ray event that proved diffusion theory is essential for describing charged particle transport in space. In the modern era, the instrument of choice is an array. The days are gone when a lone neutron monitor placed anywhere on Earth can make discoveries. Now and in the future, science with neutron monitors will require coordinated arrays of detectors that enable continuous, realtime measurement of the cosmic ray directional distribution and energy spectrum. An emerging application for neutron monitors is in the field of space weather prediction and specification, especially as concerns major radiation hazard from solar particles.

  7. Personnel neutron dose assessment upgrade: Volume 2, Field neutron spectrometer for health physics applications

    SciTech Connect

    Brackenbush, L.W.; Reece, W.D.; Miller, S.D.; Endres, G.W.R.; Durham, J.S.; Scherpelz, R.I.; Tomeraasen, P.L.; Stroud, C.M.; Faust, L.G.; Vallario, E.J.

    1988-07-01

    Both the (ICRP) and the (NCPR) have recommended an increase in neutron quality factors and the adoption of effective dose equivalent methods. The series of reports entitled Personnel Neutron Dose Assessment Upgrade (PNL-6620) addresses these changes. Volume 1 in this series of reports (Personnel Neutron Dosimetry Assessment) provided guidance on the characteristics, use, and calibration of personnel neutron dosimeters in order to meet the new recommendations. This report, Volume 2: Field Neutron Spectrometer for Health Physics Applications describes the development of a portable field spectrometer which can be set up for use in a few minutes by a single person. The field spectrometer described herein represents a significant advance in improving the accuracy of neutron dose assessment. It permits an immediate analysis of the energy spectral distribution associated with the radiation from which neutron quality factor can be determined. It is now possible to depart from the use of maximum Q by determining and realistically applying a lower Q based on spectral data. The field spectrometer is made up of two modules: a detector module with built-in electronics and an analysis module with a IBM PC/reg sign/-compatible computer to control the data acquisition and analysis of data in the field. The unit is simple enough to allow the operator to perform spectral measurements with minimal training. The instrument is intended for use in steady-state radiation fields with neutrons energies covering the fission spectrum range. The prototype field spectrometer has been field tested in plutonium processing facilities, and has been proven to operate satisfactorily. The prototype field spectrometer uses a /sup 3/He proportional counter to measure the neutron energy spectrum between 50 keV and 5 MeV and a tissue equivalent proportional counter (TEPC) to measure absorbed neutron dose.

  8. A sensate liner for personnel monitoring applications

    NASA Astrophysics Data System (ADS)

    Lind, Eric J.; Jayaraman, Sundaresan; Park, Ms. Sungmee; Rajamanickam, Rangaswamy; Eisler, Robert, , Dr.; Burghart, Mr. George; McKee, Mr. Tony

    This program develops and demonstrates technologies useful for implementing a manageable cost effective systems approach to monitoring the medical condition of personnel by way of an instrumented uniform hereafter referred to as a Sensate Liner (SL). The SL consists of a form fitting garment which contains and interconnects sensing elements and devices to an electronics pack containing a processor and transmitter. The SL prototype requires fiber, textile, garment and sensor development. The SL textile consists of a mesh of electrically and optically conductive fibers integrated into the normal structure (woven or knitted) of fibers and yarns selected for comfort and durability. A suite of SL garment compatible embedded biological and physical sensors are then integrated into the SL. The initial SL sensor suite is selected to improve triage for combat casualties. Additional SL sensor concepts for medical monitoring will be discussed.

  9. A Sensate Liner for personnel monitoring applications.

    PubMed

    Lind, E J; Jayaraman, S; Park, S; Rajamanickam, R; Eisler, R; Burghart, G; McKee, T

    1998-01-01

    This program develops and demonstrates technologies useful for implementing a manageable cost effective systems approach to monitoring the medical condition of personnel by way of an instrumented uniform hereafter referred to as a Sensate Liner (SL). The SL consists of a form fitting garment which contains and interconnects sensing elements and devices to an electronics pack containing a processor and transmitter. The SL prototype requires fiber, textile, garment and sensor development. The SL textile consists of a mesh of electrically and optically conductive fibers integrated into the normal structure (woven or knitted) of fibers and yarns selected for comfort and durability. A suite of SL garment compatible embedded biological and physical sensors are then integrated into the SL. The initial SL sensor suite is selected to improve triage for combat casualties. Additional SL sensor concepts for medical monitoring will be discussed.

  10. [Current state and prospects of military personnel health monitoring].

    PubMed

    Rezvantsev, M V; Kuznetsov, S M; Ivanov, V V; Zakurdaev, V V

    2014-01-01

    The current article is dedicated to some features of the Russian Federation Armed Forces military personnel health monitoring such as legal and informational provision, methodological basis of functioning, historical aspect of formation and development of the social and hygienic monitoring in the Russian Federation Armed Forces. The term "military personnel health monitoring" is defined as an analytical system of constant and long-term observation, analysis, assessment, studying of factors determined the military personnel health, these factors correlations, health risk factors management in order to minimize them. The current state of the military personnel health monitoring allows coming to the conclusion that the military health system does have forces and resources for state policy of establishing the population health monitoring system implementation. The following directions of the militarily personnel health monitoring improvement are proposed: the Russian Federation Armed Forces medical service record and report system reorganization bringing it closer to the civilian one, implementation of the integrated approach to the medical service informatisation, namely, military personnel health status and medical service resources monitoring. The leading means in this direction are development and introduction of a military serviceman individual health status monitoring system on the basis of a serviceman electronic medical record card. Also it is proposed the current Russian Federation Armed Forces social and hygienic monitoring improvement at the expense of informational interaction between the two subsystems on the basis of unified military medical service space.

  11. 10 CFR 34.47 - Personnel monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in place of ion-chamber pocket dosimeters. (2) Each personnel dosimeter must be assigned to and worn... associated with licensed material use until a determination of the individual's radiation exposure has...

  12. 10 CFR 34.47 - Personnel monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... in place of ion-chamber pocket dosimeters. (2) Each personnel dosimeter must be assigned to and worn... associated with licensed material use until a determination of the individual's radiation exposure has...

  13. 10 CFR 34.47 - Personnel monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in place of ion-chamber pocket dosimeters. (2) Each personnel dosimeter must be assigned to and worn... associated with licensed material use until a determination of the individual's radiation exposure has...

  14. 10 CFR 34.47 - Personnel monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... in place of ion-chamber pocket dosimeters. (2) Each personnel dosimeter must be assigned to and worn... associated with licensed material use until a determination of the individual's radiation exposure has...

  15. Neutron monitors : self-indication of shielding

    SciTech Connect

    Menlove, Howard O.; Swinhoe, M. T.

    2004-01-01

    Neutron monitoring is extensively used in safeguards to detect the passage of nuclear material. In many of these applications neutron monitors are coupled with camera surveillance systems. In addition to recording movement of items of interest, the camera system has also been traditionally used to confirm that no neutron shielding has been placed around the monitors and that therefore they are still effectively monitoring the area. Using cameras for this purpose means that the neutron monitoring system cannot be considered a single layer of containment and surveillance by itself because it needs the camera system to ensure that it is still operational. However, the potential diverter would need to apply a significant amount of shielding to mask the movement of a typical item. This shelding would affect the 'background' counting rate of each neutron monitor, due to cosmic rays or nuclear material in the vicinity. This change in counting rate can be used to determine if shielding has been applied to the monitor. Thus, the neutron monitor provides a self-indication that shielding has been applied and the dependence on the camera data is removed. This paper gives numerical examples for the case of a nuclear material storage area and proposes that neutron monitors can be used as a stand-alone layer for containment and surveillance purposes.

  16. Application of the TLD albedo technique for monitoring and interpretation of neutron stray radiation fields

    NASA Astrophysics Data System (ADS)

    Piesch, E.; Burgkhardt, B.

    1980-09-01

    A single sphere albedo technique with TLD 600/TLD 700 detectors has been applied in neutron monitoring to calibrate albedo dosimeters and to interpret neutron stray radiation fields in terms of neutron dose equivalent separated for the energy groups below 0.4 eV, 0.4-10 keV and 10 keV-10 MeV, and Eeff for fast neutrons. The paper describes the technique for field and personnel monitoring under the aspect of an on-line computer program for data recording and processing.

  17. Heliospheric modulation strength: effective neutron monitor energy

    NASA Astrophysics Data System (ADS)

    Alanko, K.; Usoskin, I. G.; Mursula, K.; Kovaltsov, G. A.

    2003-08-01

    The widely used concept of the neutron monitor energy range is not well defined. Also, the median energy of a neutron monitor varies in the course of the solar cycle. Here we present a new concept of the effective energy of cosmic rays as measured by neutron monitors. Using a spherically-symmetric model of the heliospheric transport of cosmic rays and the specific yield function of a neutron monitor, we show that there is such an effective energy that the count rate of a given neutron monitor is directly proportional to the flux of cosmic rays with energy above this effective energy, irrespectively of the phase of the solar cycle. The new concept of the effective energy allows to regard the neutron monitor count rate as a direct measurement of the galactic cosmic ray flux with energy above this value. The effective energy varies from about 6 GeV for polar up to about 50 GeV for equatorial stations (e.g., it is about 6.5 GeV for high-latitude Oulu, 8 GeV for mid-latitude Climax and 40 GeV for equatorial Huancayo NM).

  18. DOE personnel neutron dosimetry evaluation and upgrade program

    SciTech Connect

    Faust, L.G.; Stroud, C.M.; Vallario, E.J.

    1988-10-01

    The US Department of Energy (DOE) sponsors an extensive research program to improve the methods, dosimeters, and instruments available to DOE facilities for measuring neutron dose and assessing its effects on the work force. The Total Dose Meter was recently developed for measuring in real time the adsorbed dose of mixed neutron and gamma radiation and for calculating the dose equivalent. The Field Neutron Spectrometer was developed to provide a portable instrument for determining neutron spectra in the workplace for flux-to-dose equivalent conversion and quality factor calculation. The Combination Thermoluminescence/Track Etch Dosimeter (TLD/TED) was developed to extend the effective neutron energy range of the conventional TLDs to improve detection of fast-energy neutrons. An Optically Stimulated Luminescence Dosimeter is presently being developed for application to gamma, neutron, and beta radiation. An Effective Dose Equivalent System is being developed to provide guidance in implementing the January 1987 Presidential Directive to determine effective dose equivalent. Superheated Drop Detectors are being investigated for their potential as real time neutron dosimeters. This paper includes discussions of these improvements brought about by the DOE research program. 3 refs.

  19. 10 CFR 34.83 - Records of personnel monitoring procedures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Records of personnel monitoring procedures. 34.83 Section 34.83 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.83 Records of...

  20. 10 CFR 34.83 - Records of personnel monitoring procedures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Records of personnel monitoring procedures. 34.83 Section 34.83 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.83 Records of...

  1. 10 CFR 34.83 - Records of personnel monitoring procedures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of personnel monitoring procedures. 34.83 Section 34.83 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.83 Records of...

  2. Neutron Exposure for DoD Nuclear Test Personnel.

    DTIC Science & Technology

    1985-08-15

    We would appreciate your providing the requested information . El Add the individual listed to your distribution list. El Delete the cited...X E -1 kilo pascal IkPa) -71 hi becquerel (1q) is ii SI unit of radioactivit ). 1 Bq I event/8 *-The Grai (G)) is the SI unit of absorbed radiation...individual’s total dose. The most important parameters required are the neutron environment generated by a particular detonation and the participant’s

  3. Retrospective assessment of personnel neutron dosimetry for workers at the Hanford Site

    SciTech Connect

    Fix, J.J.; Wilson, R.H.; Baumgartner, W.B.

    1996-09-01

    This report was prepared to examine the specific issue of the potential for unrecorded neutron dose for Hanford workers, particularly in comparison with the recorded whole body (neutron plus photon) dose. During the past several years, historical personnel dosimetry practices at Hanford have been documented in several technical reports. This documentation provides a detailed history of the technology, radiation fields, and administrative practices used to measure and record dose for Hanford workers. Importantly, documentation has been prepared by personnel whose collective experience spans nearly the entire history of Hanford operations beginning in the mid-1940s. Evaluations of selected Hanford radiation dose records have been conducted along with statistical profiles of the recorded dose data. The history of Hanford personnel dosimetry is complex, spanning substantial evolution in radiation protection technology, concepts, and standards. Epidemiologic assessments of Hanford worker mortality and radiation dose data were initiated in the early 1960s. In recent years, Hanford data have been included in combined analyses of worker cohorts from several Department of Energy (DOE) sites and from several countries through the International Agency for Research on Cancer (IARC). Hanford data have also been included in the DOE Comprehensive Epidemiologic Data Resource (CEDR). In the analysis of Hanford, and other site data, the question of comparability of recorded dose through time and across the respective sites has arisen. DOE formed a dosimetry working group composed of dosimetrists and epidemiologists to evaluate data and documentation requirements of CEDR. This working group included in its recommendations the high priority for documentation of site-specific radiation dosimetry practices used to measure and record worker dose by the respective DOE sites.

  4. A High Count Rate Neutron Beam Monitor for Neutron Scattering Facilities

    SciTech Connect

    Barnett, Amanda; Crow, Lowell; Diawara, Yacouba; Hayward, J P; Hayward, Jason P; Menhard, Kocsis; Sedov, Vladislav N; Funk, Loren L

    2013-01-01

    Abstract Beam monitors are an important diagnostic tool in neutron science facilities. Present beam monitors use either ionization chambers in integration mode, which are slow and have no timing information, or pulse counters which can easily be saturated by high beam intensities. At high flux neutron scattering facilities, neutron beam monitors with very low intrinsic efficiency (10-5) are presently selected to keep the counting rate within a feasible range, even when a higher efficiency would improve the counting statistics and yield a better measurement of the incident beam. In this work, we report on a high count rate neutron beam monitor. This beam monitor offers good timing with an intrinsic efficiency of 10-3 and a counting rate capability of over 1,000,000 cps without saturation.

  5. Integrated neutron/gamma-ray portal monitors for nuclear safeguards

    NASA Astrophysics Data System (ADS)

    Fehlau, Paul E.

    1994-08-01

    Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. We compared the influence of the two methods of integration on detecting neutrons and gamma rays, and we examined the effectiveness of other design factors and the methods for signal detection as well.

  6. Integrated neutron/gamma-ray portal monitors for nuclear safeguards

    SciTech Connect

    Fehlau, P.E. )

    1994-08-01

    Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. The authors compared the influence of the two methods of integration on detecting neutrons and gamma rays, and they examined the effectiveness of other design factors and the methods for signal detection as well.

  7. Integrated neutron/gamma-ray portal monitors for nuclear safeguards

    SciTech Connect

    Fehlau, P.E.

    1993-09-01

    Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. We compared the influence of the two methods of integration on detecting neutrons and gamma rays, and we examined the effectiveness of other design factors and the methods for signal detection as well.

  8. Improved monitoring system of neutron flux during boron-neutron capture therapy

    SciTech Connect

    Harasawa, S.; Nakamoto, A.; Hayakawa, Y.; Egawa, J.

    1981-10-01

    Continuous and simultaneous monitoring of neutron flux in the course of a boron-neutron capture operation on a brain tumor has been achieved using a new monitoring system. A silicon surface barrier diode mounted with /sup 6/LiF instead of the previously reported borax is used to sense neutrons. The pulse heights of /sup 3/H and ..cap alpha.. particles from /sup 6/Li(n, ..cap alpha..)/sup 2/H reaction are sufficiently high and well separated from noises due to ..gamma.. rays. The effect of pulse-height reduction due to the radiation damage of the diode thus becomes smaller, permitting continuous monitoring. The relative error of the monitoring is within 2% over 5 hr for a neutron-flux density of 2 x 10/sup 9/ n/cm/sup 2/ sec.

  9. Ultra Wide Band RFID Neutron Tags for Nuclear Materials Monitoring

    SciTech Connect

    Nekoogar, F; Dowla, F; Wang, T

    2010-01-27

    Recent advancements in the ultra-wide band Radio Frequency Identification (RFID) technology and solid state pillar type neutron detectors have enabled us to move forward in combining both technologies for advanced neutron monitoring. The LLNL RFID tag is totally passive and will operate indefinitely without the need for batteries. The tag is compact, can be directly mounted on metal, and has high performance in dense and cluttered environments. The LLNL coin-sized pillar solid state neutron detector has achieved a thermal neutron detection efficiency of 20% and neutron/gamma discrimination of 1E5. These performance values are comparable to a fieldable {sup 3}He based detector. In this paper we will discuss features about the two technologies and some potential applications for the advanced safeguarding of nuclear materials.

  10. A proposed fiber-optic neutron monitor

    NASA Astrophysics Data System (ADS)

    Weiss, Jonathan D.

    2013-02-01

    An interferometric fiber-optic sensor is proposed as a neutron detector. The basic mechanism is the absorption of neutrons by the constituent atoms of the fiber: silicon, germanium, and oxygen. As a result, the isotopic mass of these elements increases and thereby decreases certain infrared vibrational frequencies. These changes impact the refractive index of the core and cladding of the fiber and therefore the propagation constant of the fundamental mode of the singlemode fibers constitutes the interferometer. This neutron-induced shift in the propagation constant produces a corresponding shift in the phase of the light emerging from one fiber of a Mach-Zehnder interferometer. A review of the basics of singlemode fibers is presented, and the changes in indexes and the propagation constant are calculated under varying shifts in isotopic mass. Reference is made to the computational tool available for a simulated sensor response. Some neutron absorption cross-sections as functions of neutron kinetic energy are presented, along with a possible design of the sensor.

  11. Athens Neutron Monitor Data Processing Center - ANMODAP Center

    NASA Astrophysics Data System (ADS)

    Mavromichalaki, H.; Gerontidou, M.; Mariatos, G.; Papailiou, M.; Papaioannou, A.; Plainaki, C.; Sarlanis, C.; Souvatzoglou, G.

    2009-11-01

    Cosmic ray measurements in Athens were initiated in November 2000 with a standard 6NM-64 neutron monitor. Within the last years an effort has been made in order to construct an effective database of neutron monitor (NM) and satellite data in real-time, regarding the necessities of space weather monitoring (Athens Neutron Monitor Data Processing Center - ANMODAP Center). The prospective goal of this network is to make possible the receiving of all data in real-time in close sequence from all servers around the globe. The graphical representation of all these data in real-time is available through the website of the station ( http://cosray.phys.uoa.gr). Moreover, a second database that collects data with 1-min resolution operates in a parallel mode. The online services as a special 'Alert' algorithm for Ground Level Enhancements (GLEs) and some models created to analyze aspects of GLEs as the neutron monitor Basic Anisotropic Neutron Ground Level Enhancement (BANGLE) model and the Forbush Decreases (FORD) model as well, are presented. Moreover, a short account on work performed on the possible relationship between the geomagnetic activity level and the biological effects is given.

  12. Neutron flux profile monitor for use in a fission reactor

    DOEpatents

    Kopp, Manfred K.; Valentine, Kenneth H.

    1983-01-01

    A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occured. Neutron flux profiles of reactor cores can be more accurately measured as a result.

  13. Neutron monitoring of plutonium at the ZPPR storage vault

    SciTech Connect

    Caldwell, J.T.; Kuckertz, T.H.; Bieri, J.M.; France, S.W.; Goin, R.W.; Hastings, R.D.; Pratt, J.C.; Shunk, E.R.

    1981-12-01

    We investigated a method for monitoring a typical large storage vault for unauthorized removal of plutonium. The method is based on the assumption that the neutron field in a vault produced by a particular geometric configuration of bulk plutonium remains constant in time and space as long as the configuration is undisturbed. To observe such a neutron field, we installed an array of 25 neutron detectors in the ceiling of a plutonium storage vault at Argonne National Laboratory West. Each neutron detector provided an independent spatial measurement of the vault neutron field. Data collected by each detector were processed to determine whether statistically significant changes had occurred in the neutron field. Continuous observation experiments measured the long-term stability of the system. Removal experiments were performed in which known quantities of plutonium were removed from the vault. Both types of experiments demonstrated that the neutron monitoring system can detect removal or addition of bulk plutonium (11% /sup 240/Pu) whose mass is as small as 0.04% of the total inventory.

  14. Mini Neutron Monitors at Concordia Research Station, Central Antarctica

    NASA Astrophysics Data System (ADS)

    Poluianov, Stepan; Usoskin, Ilya; Mishev, Alexander; Moraal, Harm; Kruger, Helena; Casasanta, Giampietro; Traversi, Rita; Udisti, Roberto

    2015-12-01

    Two mini neutron monitors are installed at Concordia research station (Dome C, Central Antarctica, 75° 06' S, 123° 23' E, 3,233 m.a.s.l.). The site has unique properties ideal for cosmic ray measurements, especially for the detection of solar energetic particles: very low cutoff rigidity < 0.01 GV, high elevation and poleward asymptotic acceptance cones pointing to geographical latitudes > 75° S. The instruments consist of a standard neutron monitor and a "bare" (lead-free) neutron monitor. The instrument operation started in mid-January 2015. The barometric correction coefficients were computed for the period from 1 February to 31 July 2015. Several interesting events, including two notable Forbush decreases on 17 March 2015 and 22 June 2015, and a solar particle event of 29 October 2015 were registered. The data sets are available at cosmicrays.oulu.fi and nmdb.eu.

  15. Suggestions for improving the efficiency of ground-based neutron monitors for detecting solar neutrons

    NASA Technical Reports Server (NTRS)

    Iucci, N.; Parisi, M.; Signorini, C.; Storini, M.; Villoresi, G.

    1985-01-01

    On the occasion of the June 3, 1982 intense gamma-ray solar flare a significant increase in counting rate due to solar neutrons was observed by the neutron monitors of Junsfraujoch and Lomnicky Stit located at middle latitudes and high altitudes. In spite of a larger detector employed and of the smaller solar zenith angle, the amplitude of the same event observed at Rome was much smaller and the statistical fluctuations of the salactic cosmic ray background higher than the ones registered at the two mountain stations, because of the greater atmospheric depth at which the Rome monitor is located. The effeciency for detecting a solar neutron event by a NM-64 monitor as a function of the Sun zenith angle, atmospheric depth and threshold rigidity of the station was studied.

  16. Optical Sensors for Monitoring Gamma and Neutron Radiation

    NASA Technical Reports Server (NTRS)

    Boyd, Clark D.

    2011-01-01

    For safety and efficiency, nuclear reactors must be carefully monitored to provide feedback that enables the fission rate to be held at a constant target level via adjustments in the position of neutron-absorbing rods and moderating coolant flow rates. For automated reactor control, the monitoring system should provide calibrated analog or digital output. The sensors must survive and produce reliable output with minimal drift for at least one to two years, for replacement only during refueling. Small sensor size is preferred to enable more sensors to be placed in the core for more detailed characterization of the local fission rate and fuel consumption, since local deviations from the norm tend to amplify themselves. Currently, reactors are monitored by local power range meters (LPRMs) based on the neutron flux or gamma thermometers based on the gamma flux. LPRMs tend to be bulky, while gamma thermometers are subject to unwanted drift. Both electronic reactor sensors are plagued by electrical noise induced by ionizing radiation near the reactor core. A fiber optic sensor system was developed that is capable of tracking thermal neutron fluence and gamma flux in order to monitor nuclear reactor fission rates. The system provides near-real-time feedback from small- profile probes that are not sensitive to electromagnetic noise. The key novel feature is the practical design of fiber optic radiation sensors. The use of an actinoid element to monitor neutron flux in fiber optic EFPI (extrinsic Fabry-Perot interferometric) sensors is a new use of material. The materials and structure used in the sensor construction can be adjusted to result in a sensor that is sensitive to just thermal, gamma, or neutron stimulus, or any combination of the three. The tested design showed low sensitivity to thermal and gamma stimuli and high sensitivity to neutrons, with a fast response time.

  17. New instruments for plant area and personnel monitoring

    SciTech Connect

    Gammage, R. B.; Hawthorne, A. R.; Vo-Dinh, T.; Schuresko, D. D.

    1980-01-01

    Advances in portable monitoring instruments and simple luminescence techniques for analyzing polynuclear aromatic hydrocarbons (PNAs) are reported. A small, derivative ultra-violet absorption spectrometer is suitable for multipollutant real-time monitoring of several mono- and bicyclic aromatic vapors. A non-compound selective fluorescence spill spotter and lightpipe luminoscope are active instruments for measuring general surface and skin contamination, respectively. A small passive integrating filter paper exposure device that responds to PNA vapors such a pyrene is a very promising and recent development. Synchronous luminescence and room temperature phosphoresence are two attractive and simple to use analytical methodologies for the rapid assaying of major PNA compounds. Their potential for analyzing the cyclohexane extract of particulate matter, or incorporation into a device for the continuous monitoring of select PNAs in aerosols in near-real-time, are discussed.

  18. Factors Affecting the Application of a Simple Ratio Technique for Spectral Correction of a Neutron Personnel Albedo Dosimeter.

    NASA Astrophysics Data System (ADS)

    Nelson, Robert Clifton

    To accurately assess the dose equivalent indicated by the albedo response of a neutron personnel dosimeter, additional knowledge is generally required in order to apply the needed spectral specific correction factors. This work was designed to evaluate the capability of the USAF Personnel Neutron Dosimeter to "self-calibrate" for moderated fission neutron spectra. The boron/bare ratio technique is compared with a simple theoretical model of the dosimeter and with the 23 cm (9 in) to 7.6 cm (3 in) Hankins' remmeter calibration technique. The overall goal was to provide dose-equivalent estimates comparable to those provided by the remmeter technique without the necessity of special on-site measurements. Although the boron/bare technique with the present dosimeter design fails to provide calibration factors needed for moderated fission neutron spectra, theoretical predictions based upon the model and the measured dosimeter responses are used to propose a dosimeter design which might fulfill the desired goal. Ancillary data gathered during the study are also presented.

  19. Installation of Neutron Monitor at the Jang Bogo Station in Antarctica

    NASA Astrophysics Data System (ADS)

    Jung, Jongil; Oh, Suyeon; Yi, Yu; Evenson, Paul; Pyle, Roger; Jee, Geonhwa; Kim, Jeong-Han; Lee, Changsup; Sohn, Jongdae

    2016-12-01

    In December 2015, we have installed neutron monitor at the Jang Bogo station in Antarctica. The Jang Bogo station is the second science station which is located at the coast (74° 37.4'S, 164° 13.7'E) of Terra Nova Bay in Northern Victoria Land of Antarctica. A neutron monitor is an instrument to detect neutrons from secondary cosmic rays collided by the atmosphere. The installation of neutron monitor at Jang Bogo station is a part of transferred mission for neutron monitor at McMurdo station of USA. Among 18 tubes of 18-NM64 neutron monitor, we have completed relocation of 6 tubes and the rest will be transferred in December 2017. Currently, comparison of data from both neutron monitors is under way and there is a good agreement between the data. The neutron monitor at Jang Bogo station will be quite useful to study the space weather when the installation is completed.

  20. Measuring and monitoring KIPT Neutron Source Facility Reactivity

    SciTech Connect

    Cao, Yan; Gohar, Yousry; Zhong, Zhaopeng

    2015-08-01

    Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on developing and constructing a neutron source facility at Kharkov, Ukraine. The facility consists of an accelerator-driven subcritical system. The accelerator has a 100 kW electron beam using 100 MeV electrons. The subcritical assembly has keff less than 0.98. To ensure the safe operation of this neutron source facility, the reactivity of the subcritical core has to be accurately determined and continuously monitored. A technique which combines the area-ratio method and the flux-to-current ratio method is purposed to determine the reactivity of the KIPT subcritical assembly at various conditions. In particular, the area-ratio method can determine the absolute reactivity of the subcritical assembly in units of dollars by performing pulsed-neutron experiments. It provides reference reactivities for the flux-to-current ratio method to track and monitor the reactivity deviations from the reference state while the facility is at other operation modes. Monte Carlo simulations are performed to simulate both methods using the numerical model of the KIPT subcritical assembly. It is found that the reactivities obtained from both the area-ratio method and the flux-to-current ratio method are spatially dependent on the neutron detector locations and types. Numerical simulations also suggest optimal neutron detector locations to minimize the spatial effects in the flux-to-current ratio method. The spatial correction factors are calculated using Monte Carlo methods for both measuring methods at the selected neutron detector locations. Monte Carlo simulations are also performed to verify the accuracy of the flux-to-current ratio method in monitoring the reactivity swing during a fuel burnup cycle.

  1. Application of an ultraminiature thermal neutron monitor for irradiation field study of accelerator-based neutron capture therapy.

    PubMed

    Ishikawa, Masayori; Tanaka, Kenichi; Endo, Satrou; Hoshi, Masaharu

    2015-03-01

    Phantom experiments to evaluate thermal neutron flux distribution were performed using the Scintillator with Optical Fiber (SOF) detector, which was developed as a thermal neutron monitor during boron neutron capture therapy (BNCT) irradiation. Compared with the gold wire activation method and Monte Carlo N-particle (MCNP) calculations, it was confirmed that the SOF detector is capable of measuring thermal neutron flux as low as 10(5) n/cm(2)/s with sufficient accuracy. The SOF detector will be useful for phantom experiments with BNCT neutron fields from low-current accelerator-based neutron sources.

  2. Application of an ultraminiature thermal neutron monitor for irradiation field study of accelerator-based neutron capture therapy

    PubMed Central

    Ishikawa, Masayori; Tanaka, Kenichi; Endo, Satrou; Hoshi, Masaharu

    2015-01-01

    Phantom experiments to evaluate thermal neutron flux distribution were performed using the Scintillator with Optical Fiber (SOF) detector, which was developed as a thermal neutron monitor during boron neutron capture therapy (BNCT) irradiation. Compared with the gold wire activation method and Monte Carlo N-particle (MCNP) calculations, it was confirmed that the SOF detector is capable of measuring thermal neutron flux as low as 105 n/cm2/s with sufficient accuracy. The SOF detector will be useful for phantom experiments with BNCT neutron fields from low-current accelerator-based neutron sources. PMID:25589504

  3. Monitoring of health care personnel employee and occupational health immunization program practices in the United States.

    PubMed

    Carrico, Ruth M; Sorrells, Nikka; Westhusing, Kelly; Wiemken, Timothy

    2014-01-01

    Recent studies have identified concerns with various elements of health care personnel immunization programs, including the handling and management of the vaccine. The purpose of this study was to assess monitoring processes that support evaluation of the care of vaccines in health care settings. An 11-question survey instrument was developed for use in scripted telephone surveys. State health departments in all 50 states in the United States and the District of Columbia were the target audience for the surveys. Data from a total of 47 states were obtained and analyzed. No states reported an existing monitoring process for evaluation of health care personnel immunization programs in their states. Our assessment indicates that vaccine evaluation processes for health care facilities are rare to nonexistent in the United States. Identifying existing practice gaps and resultant opportunities for improvements may be an important safety initiative that protects patients and health care personnel.

  4. Assessing and Monitoring Student Progress in an E-Learning Personnel Preparation Environment.

    ERIC Educational Resources Information Center

    Meyen, Edward L.; Aust, Ronald J.; Bui, Yvonne N.; Isaacson, Robert

    2002-01-01

    Discussion of e-learning in special education personnel preparation focuses on student assessment in e-learning environments. It includes a review of the literature, lessons learned by the authors from assessing student performance in e-learning environments, a literature perspective on electronic portfolios in monitoring student progress, and the…

  5. 41 CFR 50-204.23 - Precautionary procedures and personnel monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... present. (b) Every employer shall supply appropriate personnel monitoring equipment, such as film badges, pocket chambers, pocket dosimeters, or film rings, to, and shall require the use of such equipment by: (1... received (e.g., film badges, pocket chambers, pocket dosimeters, film rings, etc.); (2) “Radiation...

  6. 41 CFR 50-204.23 - Precautionary procedures and personnel monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... materials and equipment, and measurements of levels of radiation or concentrations of radioactive material present. (b) Every employer shall supply appropriate personnel monitoring equipment, such as film badges... receive, a dose in any calendar quarter in excess of 25 percent of the applicable value specified...

  7. MONITORING SHORT-TERM COSMIC-RAY SPECTRAL VARIATIONS USING NEUTRON MONITOR TIME-DELAY MEASUREMENTS

    SciTech Connect

    Ruffolo, D.; Sáiz, A.; Mangeard, P.-S.; Kamyan, N.; Muangha, P.; Nutaro, T.; Rujiwarodom, M.; Tooprakai, P.; Sumran, S.; Chaiwattana, C.; Gasiprong, N.; Channok, C.; Wuttiya, C.; Asavapibhop, B.; Bieber, J. W.; Clem, J.; Evenson, P.; Munakata, K.

    2016-01-20

    Neutron monitors (NMs) are ground-based detectors of cosmic-ray showers that are widely used for high-precision monitoring of changes in the Galactic cosmic-ray (GCR) flux due to solar storms and solar wind variations. In the present work, we show that a single neutron monitor station can also monitor short-term changes in the GCR spectrum, avoiding the systematic uncertainties in comparing data from different stations, by means of NM time-delay histograms. Using data for 2007–2014 from the Princess Sirindhorn Neutron Monitor, a station at Doi Inthanon, Thailand, with the world’s highest vertical geomagnetic cutoff rigidity of 16.8 GV, we have developed an analysis of time-delay histograms that removes the chance coincidences that can dominate conventional measures of multiplicity. We infer the “leader fraction” L of neutron counts that do not follow a previous neutron count in the same counter from the same atmospheric secondary, which is inversely related to the actual multiplicity and increases for increasing GCR spectral index. After correction for atmospheric pressure and water vapor, we find that L indicates substantial short-term GCR spectral hardening during some but not all Forbush decreases in GCR flux due to solar storms. Such spectral data from Doi Inthanon provide information about cosmic-ray energies beyond the Earth’s maximum geomagnetic cutoff, extending the reach of the worldwide NM network and opening a new avenue in the study of short-term GCR decreases.

  8. Monitoring Short-term Cosmic-ray Spectral Variations Using Neutron Monitor Time-delay Measurements

    NASA Astrophysics Data System (ADS)

    Ruffolo, D.; Sáiz, A.; Mangeard, P.-S.; Kamyan, N.; Muangha, P.; Nutaro, T.; Sumran, S.; Chaiwattana, C.; Gasiprong, N.; Channok, C.; Wuttiya, C.; Rujiwarodom, M.; Tooprakai, P.; Asavapibhop, B.; Bieber, J. W.; Clem, J.; Evenson, P.; Munakata, K.

    2016-01-01

    Neutron monitors (NMs) are ground-based detectors of cosmic-ray showers that are widely used for high-precision monitoring of changes in the Galactic cosmic-ray (GCR) flux due to solar storms and solar wind variations. In the present work, we show that a single neutron monitor station can also monitor short-term changes in the GCR spectrum, avoiding the systematic uncertainties in comparing data from different stations, by means of NM time-delay histograms. Using data for 2007-2014 from the Princess Sirindhorn Neutron Monitor, a station at Doi Inthanon, Thailand, with the world’s highest vertical geomagnetic cutoff rigidity of 16.8 GV, we have developed an analysis of time-delay histograms that removes the chance coincidences that can dominate conventional measures of multiplicity. We infer the “leader fraction” L of neutron counts that do not follow a previous neutron count in the same counter from the same atmospheric secondary, which is inversely related to the actual multiplicity and increases for increasing GCR spectral index. After correction for atmospheric pressure and water vapor, we find that L indicates substantial short-term GCR spectral hardening during some but not all Forbush decreases in GCR flux due to solar storms. Such spectral data from Doi Inthanon provide information about cosmic-ray energies beyond the Earth’s maximum geomagnetic cutoff, extending the reach of the worldwide NM network and opening a new avenue in the study of short-term GCR decreases.

  9. Cosmic ray modulation studies with Lead-Free Gulmarg Neutron Monitor

    NASA Astrophysics Data System (ADS)

    Darzi, M. A.; Ishtiaq, P. M.; Mir, T. A.; Mufti, S.; Shah, G. N.

    2014-02-01

    A lead-free neutron monitor operating at High Altitude Research Laboratory (HARL), Gulmarg optimized for detecting 2.45 MeV neutron bursts produced during the atmospheric lightning discharges is also concurrently used for studying background neutron component present in the atmosphere. These background neutrons are produced due to the interaction of primary cosmic rays with the atmospheric constituents. In order to study and extract the information about the yield of the neutron production during transient atmospheric lightning discharges, the system is continuously operated to monitor and record the cosmic ray produced background secondary neutrons in the atmosphere. The data analysis of the background neutrons recorded by Lead-Free Gulmarg Neutron Monitor (LFGNM) has convincingly established that the modulation effects due to solar activity phenomena compare very well with those monitored by the worldwide IGY or NM64 type neutron monitors which have optimum energy response relatively towards the higher energy regime of the cosmic rays. The data has revealed various types of modulation phenomena like diurnal variation, Forbush decrease etc. during its entire operational period. However, a new kind of a periodic/seasonal variation pattern is also revealed in the data from September 2007 to September 2012, which is seen to be significantly consistent with the data recorded by Emilio Segre observatory, Israel (ESOI) Neutron Monitor. Interestingly, both these neutron monitors have comparable latitude and altitude. However, the same type of consistency is not observed in the data recorded by the other conventional neutron monitors operating across the globe.

  10. Performance study of polycrystalline CVD diamond detectors for fast neutron monitoring

    SciTech Connect

    Singh, Arvind Kumar, Amit Topkar, Anita

    2014-04-24

    Diamond detectors using polycrystalline CVD diamond substrates of thickness 300μm and 100μm were fabricated for fast neutron monitoring application.. The characterization of detectors was carried out using various tests such as leakage current, capacitance and alpha particle response. The performance of detectors was evaluated for fast neutrons at different neutron yields. The results presented in this work demonstrate that the diamond detectors will be suitable for monitoring fast neutrons.

  11. A single-crystal diamond-based thermal neutron beam monitor for instruments at pulsed neutron sources

    NASA Astrophysics Data System (ADS)

    Pietropaolo, A.; Verona Rinati, G.; Verona, C.; Schooneveld, E. M.; Angelone, M.; Pillon, M.

    2009-11-01

    Single-crystal diamond detectors manufactured through a Chemical Vapour Deposition (CVD) technique are recent technology devices that have been employed in reactor and Tokamak environments in order to detect both thermal and almost monochromatic 14 MeV neutrons produced in deuterium-tritium ( d-t) nuclear fusion reactions. Their robustness and compactness are the key features that can be exploited for different applications as well. Aim of the present experimental investigation is the assessment of the performance of a diamond detector as a thermal neutron beam monitor at pulsed neutron sources. To this aim, a test measurement was carried out on the Italian Neutron Experimental Station (INES) beam line at the ISIS spallation neutron source (Great Britain). The experiment has shown the capability of these devices to work at a pulsed neutron source for beam monitoring purposes. Other interesting possible applications are also suggested.

  12. Neutron monitor generated data distributions in quantum variational Monte Carlo

    NASA Astrophysics Data System (ADS)

    Kussainov, A. S.; Pya, N.

    2016-08-01

    We have assessed the potential applications of the neutron monitor hardware as random number generator for normal and uniform distributions. The data tables from the acquisition channels with no extreme changes in the signal level were chosen as the retrospective model. The stochastic component was extracted by fitting the raw data with splines and then subtracting the fit. Scaling the extracted data to zero mean and variance of one is sufficient to obtain a stable standard normal random variate. Distributions under consideration pass all available normality tests. Inverse transform sampling is suggested to use as a source of the uniform random numbers. Variational Monte Carlo method for quantum harmonic oscillator was used to test the quality of our random numbers. If the data delivery rate is of importance and the conventional one minute resolution neutron count is insufficient, we could always settle for an efficient seed generator to feed into the faster algorithmic random number generator or create a buffer.

  13. Demonstration of the importance of a dedicated neutron beam monitoring system for BNCT facility.

    PubMed

    Chao, Der-Sheng; Liu, Yuan-Hao; Jiang, Shiang-Huei

    2016-01-01

    The neutron beam monitoring system is indispensable to BNCT facility in order to achieve an accurate patient dose delivery. The neutron beam monitoring of a reactor-based BNCT (RB-BNCT) facility can be implemented through the instrumentation and control system of a reactor provided that the reactor power level remains constant during reactor operation. However, since the neutron flux in reactor core is highly correlative to complicated reactor kinetics resulting from such as fuel depletion, poison production, and control blade movement, some extent of variation may occur in the spatial distribution of neutron flux in reactor core. Therefore, a dedicated neutron beam monitoring system is needed to be installed in the vicinity of the beam path close to the beam exit of the RB-BNCT facility, where it can measure the BNCT beam intensity as closely as possible and be free from the influence of the objects present around the beam exit. In this study, in order to demonstrate the importance of a dedicated BNCT neutron beam monitoring system, the signals originating from the two in-core neutron detectors installed at THOR were extracted and compared with the three dedicated neutron beam monitors of the THOR BNCT facility. The correlation of the readings between the in-core neutron detectors and the BNCT neutron beam monitors was established to evaluate the improvable quality of the beam intensity measurement inferred by the in-core neutron detectors. In 29 sampled intervals within 16 days of measurement, the fluctuations in the mean value of the normalized ratios between readings of the three BNCT neutron beam monitors lay within 0.2%. However, the normalized ratios of readings of the two in-core neutron detectors to one of the BNCT neutron beam monitors show great fluctuations of 5.9% and 17.5%, respectively.

  14. A scientific database for real-time Neutron Monitor measurements - taking Neutron Monitors into the 21st century

    NASA Astrophysics Data System (ADS)

    Steigies, Christian

    2012-07-01

    The Neutron Monitor Database project, www.nmdb.eu, has been funded in 2008 and 2009 by the European Commission's 7th framework program (FP7). Neutron monitors (NMs) have been in use worldwide since the International Geophysical Year (IGY) in 1957 and cosmic ray data from the IGY and the improved NM64 NMs has been distributed since this time, but a common data format existed only for data with one hour resolution. This data was first distributed in printed books, later via the World Data Center ftp server. In the 1990's the first NM stations started to record data at higher resolutions (typically 1 minute) and publish in on their webpages. However, every NM station chose their own format, making it cumbersome to work with this distributed data. In NMDB all European and some neighboring NM stations came together to agree on a common format for high-resolution data and made this available via a centralized database. The goal of NMDB is to make all data from all NM stations available in real-time. The original NMDB network has recently been joined by the Bartol Research Institute (Newark DE, USA), the National Autonomous University of Mexico and the North-West University (Potchefstroom, South Africa). The data is accessible to everyone via an easy to use webinterface, but expert users can also directly access the database to build applications like real-time space weather alerts. Even though SQL databases are used today by most webservices (blogs, wikis, social media, e-commerce), the power of an SQL database has not yet been fully realized by the scientific community. In training courses, we are teaching how to make use of NMDB, how to join NMDB, and how to ensure the data quality. The present status of the extended NMDB will be presented. The consortium welcomes further data providers to help increase the scientific contributions of the worldwide neutron monitor network to heliospheric physics and space weather.

  15. Absolute monitoring of DD and DT neutron fluences using the associated-particle technique

    NASA Astrophysics Data System (ADS)

    Hertel, N. E.; Wehring, B. W.

    1980-06-01

    An associated-particle system was constructed for use with a Texas Nuclear neutron generator. Associated-particle and neutron energy spectra were measured simultaneously using this system and an NE-213 proton recoil spectrometer, respectively. The associated-particle system proved to be not only an accurate monitor of DT neutron fluence, but also an accurate monitor of DD contamination in the DT spectrum. The DD and DT neutron fluences calculated from the measured associated-particle counting rates showed the best agreement with the measured neutron fluences when the laboratory distributions were assumed to be isotropic.

  16. Monte Carlo simulation of the neutron monitor yield function

    NASA Astrophysics Data System (ADS)

    Mangeard, P.-S.; Ruffolo, D.; Sáiz, A.; Madlee, S.; Nutaro, T.

    2016-08-01

    Neutron monitors (NMs) are ground-based detectors that measure variations of the Galactic cosmic ray flux at GV range rigidities. Differences in configuration, electronics, surroundings, and location induce systematic effects on the calculation of the yield functions of NMs worldwide. Different estimates of NM yield functions can differ by a factor of 2 or more. In this work, we present new Monte Carlo simulations to calculate NM yield functions and perform an absolute (not relative) comparison with the count rate of the Princess Sirindhorn Neutron Monitor (PSNM) at Doi Inthanon, Thailand, both for the entire monitor and for individual counter tubes. We model the atmosphere using profiles from the Global Data Assimilation System database and the Naval Research Laboratory Mass Spectrometer, Incoherent Scatter Radar Extended model. Using FLUKA software and the detailed geometry of PSNM, we calculated the PSNM yield functions for protons and alpha particles. An agreement better than 9% was achieved between the PSNM observations and the simulated count rate during the solar minimum of December 2009. The systematic effect from the electronic dead time was studied as a function of primary cosmic ray rigidity at the top of the atmosphere up to 1 TV. We show that the effect is not negligible and can reach 35% at high rigidity for a dead time >1 ms. We analyzed the response function of each counter tube at PSNM using its actual dead time, and we provide normalization coefficients between count rates for various tube configurations in the standard NM64 design that are valid to within ˜1% for such stations worldwide.

  17. Evaluation of H*(10) using the developed spherical type neutron dose monitor.

    PubMed

    Bhuiya, S H; Yamanishi, H; Uda, T

    2010-10-01

    An instrument for evaluating the neutron ambient dose equivalent has been developed. It has the characteristic of uniform response to wide energy of neutrons. The monitor is four-layered spherically shaped, based on moderation and absorption of neutrons. Neutron dose can be evaluated from the linear combination of three specific responses of thermoluminescent dosimeters (TLDs), which are located at three depths in the moderator. TLDs were arranged between layers of two consecutive depths on 12 radial axes at even intervals so that the monitor is equally sensitive to all directions of neutrons. In order to verify the usefulness of dose evaluation by the monitor, irradiation experiments were conducted at the FRS, JAEA. The D2O-moderated 252Cf was used for the calibration of the monitor. Experiments were also conducted by using two neutron sources of 252Cf bare and 241Am-Be. As a result, the evaluated dose for each irradiation was obtained close to the actual irradiated dose. It was confirmed that the method of dose evaluation by the developed monitor can be applied to practical neutron fields where the distance of neutron source is unknown.

  18. An estimate of the propagated uncertainty for a dosemeter algorithm used for personnel monitoring.

    PubMed

    Veinot, K G

    2015-03-01

    The Y-12 National Security Complex utilises thermoluminescent dosemeters (TLDs) to monitor personnel for external radiation doses. The TLD consist of four elements positioned behind various filters, and dosemeters are processed on site and input into an algorithm to determine worker dose. When processing dosemeters and determining the dose equivalent to the worker, a number of steps are involved, including TLD reader calibration, TLD element calibration, corrections for fade and background, and inherent sensitivities of the dosemeter algorithm. In order to better understand the total uncertainty in calculated doses, a series of calculations were performed using certain assumptions and measurement data. Individual contributions to the uncertainty were propagated through the process, including final dose calculations for a number of representative source types. Although the uncertainty in a worker's calculated dose is not formally reported, these calculations can be used to verify the adequacy of a facility's dosimetry process.

  19. PRD3000: A novel Personnel Radiation Detector with Radiation Exposure Monitoring

    SciTech Connect

    Fallu-Labruyere, A.; Micou, C.; Schulcz, F.; Fellinger, J.

    2015-07-01

    PRD3000{sup TM} is a novel Personal Radiation Detector (PRD) with personnel radiation dose exposure monitoring. It is intended for First Responders, Law Enforcement, Customs Inspectors protecting critical infrastructures for detecting unexpected radioactive sources, who also need real time Hp(10) dose equivalent information. Traditional PRD devices use scintillator materials instrumented through either a photomultiplier tube or a photodiode photodetector. While the former is bulky and sensitive to magnetic fields, the latter has to compromise radiation sensitivity and energy threshold given its current noise per unit of photo-detection surface. Recently, solid state photodetectors (SiPM), based on arrays of Geiger operated diodes, have emerged as a scalable digital photodetector for photon counting. Their strong breakdown voltage temperature dependence (on the order of tens of milli-volts per K) has however limited their use for portable instruments where strong temperature gradients can be experienced, and limited power is available to temperature stabilize. The PRD3000 is based on the industry standard DMC3000 active dosimeter that complies with IEC 61526 Ed. 3 and ANSI 42.20 for direct reading personal dose equivalent meters and active personnel radiation monitors. An extension module is based on a CsI(Tl) scintillator readout by a temperature compensated SiPM. Preliminary nuclear tests combined with a measured continuous operation in excess of 240 hours from a single AAA battery cell indicate that the PRD3000 complies with the IEC 62401 Ed.2 and ANSI 42.32 without sacrificing battery life time. We present a summary of the device test results, starting with performance stability over a temperature range of - 20 deg. C to 50 deg. C, false alarm rates and dynamic response time. (authors)

  20. Biological monitoring of hospital pharmacy personnel occupationally exposed to cytostatic drugs: urinary excretion and cytogenetics studies.

    PubMed

    Ensslin, A S; Huber, R; Pethran, A; Römmelt, H; Schierl, R; Kulka, U; Fruhmann, G

    1997-01-01

    For evaluation of the risk borne by hospital pharmacy personnel exposed to antineoplastic agents, the incorporation of cyclophosphamide, ifosfamide, and platinum-containing drugs was quantified by the determination of urinary concentrations. In addition, the induction of micronuclei (MN) and sister-chromatid-exchange (SCE) rates in peripheral blood lymphocytes were studied for correlation with the urinary excretion of cytostatic drugs. Cyclophosphamide and ifosfamide were determined in 24-h urine samples using gas chromatography with electron capture (detection limit 2.5 micrograms/l). Voltammetric analysis enabled the determination of platinum concentrations of 4 ng/l. Heparinized blood (20 ml) was drawn and lymphocytes were cultured for MN and SCE studies. In all, 13 hospital pharmacists and pharmacy technicians regularly involved in the preparation of cytostatic drugs participated in this investigation (7 persons represent a follow-up group). All subjects applied standard safety precautions, including the use of a vertical laminar air-flow hood, protective gowns, and latex gloves. On the day of urine sampling an average of 4,870 mg cyclophosphamide, 5,580 mg ifosfamide, and 504 mg platinum-containing drugs were handled. The excretion of 5 and 9 micrograms cyclophosphamide/l urine was measured in two samples, respectively. An elevated level of urinary platinum was found in one pharmacist (22.3 ng/g creatinine) in comparison with a nonexposed control group. Mean frequencies of MN and SCE did not differ significantly between the drug exposed group and control group. The employees who had incorporated chemotherapeutic agents were part of the follow-up group and, thus, particularly cautious and sensitive to a possible hazard. The results emphasize the necessity of improving personal protection of hospital pharmacy personnel occupationally exposed to cytostatic drugs and support the importance of biological monitoring. In an ongoing project in our department the

  1. Optimal design of an internal monitoring program for personnel in the Chornobyl exclusion zone radwaste management industrial complex.

    PubMed

    Bondarenko, O O; Medvedev, S Yu; Novikov, O E; Andreyev, V V

    2007-01-01

    Modern state and approach regarding organisation of individual internal dose monitoring of the personnel of industrial complex for radioactive waste management at the Chornobyl exclusion zone (CEZ) is presented. Sensitivity and adequacy of the acknowledged instrumental methods is considered taking into account the features of interpretation using indirect methods in the specific working conditions of industrial complex for radioactive waste management at the CEZ. The performed analysis enables clear recommendations to be made with regard to optimum design of an internal monitoring program for personnel, including application of specific techniques.

  2. INVESTIGATION OF A FAST NEUTRON MONITORING SYSTEM USING SEMICONDUCTOR DETECTORS.

    DTIC Science & Technology

    EFFECTS, PREAMPLIFIERS, INTEGRATED CIRCUITS, SOLAR CELLS, CALIFORNIUM , RADIOACTIVE ISOTOPES, SENSITIVITY, GAMMA RAYS, TEMPERATURE, SILICON ALLOYS, GALLIUM ALLOYS, ARSENIC ALLOYS, CARBIDES, FAST NEUTRONS.

  3. Wireless, in-vessel neutron monitor for initial core-loading of advanced breeder reactors

    NASA Technical Reports Server (NTRS)

    Delorenzo, J. T.; Kennedy, E. J.; Blalock, T. V.; Rochelle, J. M.; Chiles, M. M.; Valentine, K. H.

    1981-01-01

    An experimental wireless, in-vessel neutron monitor was developed to measure the reactivity of an advanced breeder reactor as the core is loaded for the first time to preclude an accidental critically incident. The environment is liquid sodium at a temperature of approx. 220 C, with negligible gamma or neutron radiation. With ultrasonic transmission of neutron data, no fundamental limitation was observed after tests at 230 C for 2000 h. The neutron sensitivity was approx. 1 count/s-nv, and the potential data transmission rate was approx. 10,000 counts/s.

  4. Diamond detector for high rate monitors of fast neutrons beams

    SciTech Connect

    Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G.

    2012-06-19

    A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

  5. Neutron intensity monitor with activation foil for p-Li neutron source for BNCT--Feasibility test of the concept.

    PubMed

    Murata, Isao; Otani, Yuki; Sato, Fuminobu

    2015-12-01

    Proton-lithium (p-Li) reaction is being examined worldwide as a candidate nuclear production reaction for accelerator based neutron source (ABNS) for BNCT. In this reaction, the emitted neutron energy is not so high, below 1 MeV, and especially in backward angles the energy is as low as about 100 keV. The intensity measurement was thus known to be difficult so far. In the present study, a simple method was investigated to monitor the absolute neutron intensity of the p-Li neutron source by employing the foil activation method based on isomer production reactions in order to cover around several hundreds keV. As a result of numerical examination, it was found that (107)Ag, (115)In and (189)Os would be feasible. Their features found out are summarized as follows: (107)Ag: The most convenient foil, since the half life is short. (115)In: The accuracy is the best at 0°, though it cannot be used for backward angles. And (189)Os: Suitable nuclide which can be used in backward angles, though the gamma-ray energy is a little too low. These would be used for p-Li source monitoring depending on measuring purposes in real BNCT scenes.

  6. Space Environment Forecasting with Neutron Monitors: Establishing a novel service for the ESA SSA Program

    NASA Astrophysics Data System (ADS)

    Papaioannou, Athanasios; Mavromichalaki, Helen; Souvatzoglou, George; Paschalis, Pavlos; Sarlanis, Christos; Dimitroulakos, John; Gerontidou, Maria

    2013-04-01

    High-energy particles released at the Sun during a solar flare or a very energetic coronal mass ejection, result to a significant intensity increase at neutron monitor measurements known as Ground Level Enhancements (GLEs). Due to their space weather impact (i.e. risks and failures at communication and navigation systems, spacecraft electronics and operations, space power systems, manned space missions, and commercial aircraft operations) it is crucial to establish a real-time operational system that would be in place to issue reliable and timely GLE Alerts. Currently, the Cosmic Ray group of the National and Kapodistrian University of Athens is working towards the establishment of a Neutron Monitor Service that will be made available via the Space Weather Portal operated by the European Space Agency (ESA), under the Space Situational Awareness (SSA) Program. To this end, a web interface providing data from multiple Neutron Monitor stations as well as an upgraded GLE Alert will be provided. Both services are now under testing and validation and they will probably enter to an operational phase next year. The core of this Neutron Monitor Service is the GLE Alert software, and therefore, the main goal of this research effort is to upgrade the existing GLE Alert software, to minimize the probability of a false alarm and to enhance the usability of the corresponding results. The ESA Neutron Monitor Service is building upon the infrastructure made available with the implementation of the High-Resolution Neutron Monitor Database (NMDB). In this work the structure of the Neutron Monitor Service for ESA SSA Program and the impact of the novel GLE Alert Service that will be made available to future users via ESA SSA web portal will be presented and further discussed.

  7. Silicon detectors for monitoring neutron beams in n-TOF beamlines

    SciTech Connect

    Cosentino, L.; Pappalardo, A.; Piscopo, M.; Finocchiaro, P.; Musumarra, A.; Barbagallo, M.; Colonna, N.; Damone, L.

    2015-07-15

    During 2014, the second experimental area (EAR2) was completed at the n-TOF neutron beam facility at CERN (n-TOF indicates neutron beam measurements by means of time of flight technique). The neutrons are produced via spallation, by means of a high-intensity 20 GeV pulsed proton beam impinging on a thick target. The resulting neutron beam covers the energy range from thermal to several GeV. In this paper, we describe two beam diagnostic devices, both exploiting silicon detectors coupled with neutron converter foils containing {sup 6}Li. The first one is based on four silicon pads and allows monitoring of the neutron beam flux as a function of the neutron energy. The second one, in beam and based on position sensitive silicon detectors, is intended for the reconstruction of the beam profile, again as a function of the neutron energy. Several electronic setups have been explored in order to overcome the issues related to the gamma flash, namely, a huge pulse present at the start of each neutron bunch which may blind the detectors for some time. The two devices were characterized with radioactive sources and also tested at the n-TOF facility at CERN. The wide energy and intensity range they proved capable of sustaining made them attractive and suitable to be used in both EAR1 and EAR2 n-TOF experimental areas, where they became immediately operational.

  8. Seventh Personnel Dosimetry Intercomparison Study

    SciTech Connect

    Swaja, R.E.; Sims, C.S.; Greene, R.T.

    1981-12-01

    The Seventh Personnel Dosimetry Intercomparison Study was conducted March 31-April 10, 1981, at the Oak Ridge National Laboratory. Dosimeters from 34 participating agencies were mounted on anthropomorphic phantoms and exposed to a range of low-level dose equivalents (1.5-15.0mSv neutron and 0.1-2.8 mSv gamma) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor, operating in the steady-state mode, served as the source of radiation for two equivalent sets of six separate exposures. Lucite and concrete shields along with the unshielded reactor provided three different neutron and gamma spectra for five of the exposures in each set. Results reported by the participating agencies showed that no single type of neutron dosimeter exhibited acceptable performance characteristics for all mixed-field environments encountered in this study. Film, TLD, and TLD-albed dosimeters were found to be inadequate for neutron dose equivalent measurements when large numbers of slow neutrons are present unless significant corrections are made to measured results. Track dosimeters indicated the least sensitivity to spectral characteristics, but did not always yield to the most accurate results. Gamma dose measurements showed that TLD-700 dosimeters produced significantly more accurate results than film dosimeters which tend to overestimate gamma doses in mixed radiation fields.

  9. Neutron Monitoring Systems for the Characterisation of Nuclear Fuel and Waste - Methodology and Applications - 12055

    SciTech Connect

    Sokcic-Kostic, M.; Langer, F.; Schultheis, R.; Braehler, G.

    2012-07-01

    The most characteristic behaviour of nuclear fuel or waste contaminated by fission material or isotopes resulting from fissile processes is the emission of neutrons. At the same time because of the high penetration of the material by neutrons, they are an ideal probe for measurement by non-destructive assay. The detection and data analysis in this case is quite different compared to methods using gamma measuring techniques. Neutron detection monitors have been in routine operation for a long time, showing their excellent detection capabilities. The neutron monitors designed for different applications have demonstrated their capabilities during daily operation in the field of burned up fuel elements and for nuclear waste with alpha activity. Lately the data analysis was refined and the quality of the results was improved by using MCNP calculations. Last but not least the layout and the calibration of neutron monitors are nowadays unfeasible without support by MCNP simulations. In the field of non-destructive assay the neutron monitors are undisputed. (authors)

  10. 41 CFR 50-204.23 - Precautionary procedures and personnel monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... materials and equipment, and measurements of levels of radiation or concentrations of radioactive material...” means any area, accessible to personnel, in which there exists radiation at such levels that a major... personnel, in which there exists radiation at such levels that a major portion of the body could receive...

  11. 41 CFR 50-204.23 - Precautionary procedures and personnel monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... materials and equipment, and measurements of levels of radiation or concentrations of radioactive material...” means any area, accessible to personnel, in which there exists radiation at such levels that a major... personnel, in which there exists radiation at such levels that a major portion of the body could receive...

  12. 41 CFR 50-204.23 - Precautionary procedures and personnel monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... materials and equipment, and measurements of levels of radiation or concentrations of radioactive material...” means any area, accessible to personnel, in which there exists radiation at such levels that a major... personnel, in which there exists radiation at such levels that a major portion of the body could receive...

  13. Neutron-flux profile monitor for use in a fission reactor

    DOEpatents

    Kopp, M.K.; Valentine, K.H.

    1981-09-15

    A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occurred. Neutron flux profiles of reactor cores can be more accurately measured as a result.

  14. Progress in development of the neutron profile monitor for the large helical device

    NASA Astrophysics Data System (ADS)

    Ogawa, K.; Isobe, M.; Takada, E.; Uchida, Y.; Ochiai, K.; Tomita, H.; Uritani, A.; Kobuchi, T.; Takeiri, Y.

    2014-11-01

    The neutron profile monitor stably operated at a high-count-rate for deuterium operations in the Large Helical Device has been developed to enhance the research on the fast-ion confinement. It is composed of a multichannel collimator, scintillation-detectors, and a field programmable gate array circuit. The entire neutron detector system was tested using an accelerator-based neutron generator. This system stably acquires the pulse data without any data loss at high-count-rate conditions up to 8 × 105 counts per second.

  15. Progress in development of the neutron profile monitor for the large helical device

    SciTech Connect

    Ogawa, K. Kobuchi, T.; Isobe, M.; Takeiri, Y.; Takada, E.; Uchida, Y.; Ochiai, K.; Tomita, H.; Uritani, A.

    2014-11-15

    The neutron profile monitor stably operated at a high-count-rate for deuterium operations in the Large Helical Device has been developed to enhance the research on the fast-ion confinement. It is composed of a multichannel collimator, scintillation-detectors, and a field programmable gate array circuit. The entire neutron detector system was tested using an accelerator-based neutron generator. This system stably acquires the pulse data without any data loss at high-count-rate conditions up to 8 × 10{sup 5} counts per second.

  16. Progress in development of the neutron profile monitor for the large helical device.

    PubMed

    Ogawa, K; Isobe, M; Takada, E; Uchida, Y; Ochiai, K; Tomita, H; Uritani, A; Kobuchi, T; Takeiri, Y

    2014-11-01

    The neutron profile monitor stably operated at a high-count-rate for deuterium operations in the Large Helical Device has been developed to enhance the research on the fast-ion confinement. It is composed of a multichannel collimator, scintillation-detectors, and a field programmable gate array circuit. The entire neutron detector system was tested using an accelerator-based neutron generator. This system stably acquires the pulse data without any data loss at high-count-rate conditions up to 8 × 10(5) counts per second.

  17. On the solar cycle variation in the barometer coefficients of high latitude neutron monitors

    NASA Technical Reports Server (NTRS)

    Kusunose, M.; Ogita, N.

    1985-01-01

    Evaluation of barometer coefficients of neutron monitors located at high latitudes has been performed by using the results of the spherical harmonic analysis based on the records from around twenty stations for twelve years from January 1966 to December 1977. The average of data at eight stations, where continuous records are available for twelve years, show that the absolute value of barometer coefficient is in positive correlation with the cosmic ray neutron intensity. The variation rate of the barometer coefficient to the cosmic ray neutron intensity is influenced by the changes in the cutoff rigidity and in the primary spectrum.

  18. RESULTS OF BACKGROUND SUBTRACTION TECHNIQUES ON THE SPALLATION NEUTRON SOURCE BEAM LOSS MONITORS

    SciTech Connect

    Pogge, James R; Zhukov, Alexander P

    2010-01-01

    Recent improvements to the Spallation Neutron Source (SNS) beam loss monitor (BLM) designs have been made with the goal of significantly reducing background noise. This paper outlines this effort and analyzes the results. The significance of this noise reduction is the ability to use the BLM sensors [1], [2], [3] distributed throughout the SNS accelerator as a method to monitor activation of components as well as monitor beam losses.

  19. Responses to solar cosmic rays of neutron monitors of a various design

    NASA Astrophysics Data System (ADS)

    Vashenyuk, E. V.; Balabin, Yu. V.; Stoker, P. H.

    The modeled and observed responses of neutron monitors of two various types: the standard 3-NM-64 and a leadless neutron moderated detector 4NMD at the SANAE South African Antarctic station during a number of large GLE events were compared to precise the specific yield of the NMD at low rigidity range. The parameters of primary relativistic solar protons outside magnetosphere: rigidity spectrum, anisotropy direction and pitch angle distribution were determined on data of the worldwide NM-64 neutron monitor network by modeling technique. The modeling included: definition of asymptotic viewing cones of the neutron monitor (NM) stations under study by the particle trajectory computations in a model magnetosphere [Tsyganenko, N.A. A model of the near magnetosphere with a down-dusk asymmetry: 1. Mathematical structure. Geophys. Res. 107(A8) 1176, doi: 10.101029/2001JA000219, 2002a; Tsyganenko, N.A. A model of the near magnetosphere with a down-dusk asymmetry: 2. Parameterization and fitting to observations. J. Geophys. Res. 107(A8) 1179, doi: 10.1029/2001JA000220, 2002b.]; calculation of the NM responses at variable primary solar proton flux parameters; determination of primary solar proton parameters outside the magnetosphere by a least square procedure at comparison of computed NM responses with observations. Then the response of both neutron monitors NM-64 and leadless NMD was calculated using the specific yield functions obtained earlier in the latitude and high-altitude survey of both instruments [Stoker, P.H. Spectra of solar proton ground level events using neutron monitor and neutron moderated detector recordings. in: Proc. 19th ICRC La Jolla, vol. 4, pp. 114-117, 1985; Stoker, P.H. Relativistic solar proton events, Space Sci. Rev. 73, 327-385, 1994.]. By fitting modeled responses to observations in a number of large GLEs the specific yield function for the NMD detector was adjusted so that it precisely described the response to solar cosmic rays.

  20. Comparisons of monthly mean cosmic ray counting rates observes from worldwide network of neutron monitors

    NASA Technical Reports Server (NTRS)

    Ryu, J. Y.; Wada, M.

    1985-01-01

    In order to examine the stability of neutron monitor observation, each of the monthly average counting rates of a neutron monitors is correlated to those of Kiel neutron monitor. The regression coefficients thus obtained are compared with the coupling coefficients of isotropic intensity radiation. The results of the comparisons for five year periods during 1963 to 1982, and for whole period are given. The variation spectrum with a single power law with an exponent of -0.75 up to 50 GV is not so unsatisfactory one. More than one half of the stations show correlations with the coefficient greater than 0.9. Some stations have shifted the level of mean counting rates by changing the instrumental characteristics which can be adjusted.

  1. Prototype development for real-time monitoring of neutron energy spectra in space

    NASA Astrophysics Data System (ADS)

    Yasuda, Hiroshi; Takada, Masashi; Yajima, Kazuaki; Goka, Tateo; Sato, Tatsuhiko; Nakamura, Takashi

    A prototype instrument for real-time monitoring of neutron spectra in a spacecraft has been developed for ISS and future interplanetary missions to moon and Mars. The monitor consists of a phoswich-type scintillation detector with a photomultiplier and a data processing unit including an unfolding program running on Windows PC. The monitor detects the signals of high-energy neutrons(>5MeV) separately from other particles and can give a whole energy spectra by incorporating the low to middle energy spectra that are estimated by calculation or with another detector such as a Bonner-Ball neutron spectrometer. The prototype has been processed in calibrations at accelerator facilities in Japan and measurements on a business jet aircraft. Results of the observations were compared to model calculations using the PHITS code.

  2. ITER Generic Diagnostic Upper Port Plug Nuclear Heating and Personnel Dose Rate Assesment Neutronics Analysis using the ATTILA Discrete Ordinates Code

    SciTech Connect

    Russell Feder and Mahmoud Z. Yousef

    2009-05-29

    Neutronics analysis to find nuclear heating rates and personnel dose rates were conducted in support of the integration of diagnostics in to the ITER Upper Port Plugs. Simplified shielding models of the Visible-Infrared diagnostic and of the ECH heating system were incorporated in to the ITER global CAD model. Results for these systems are representative of typical designs with maximum shielding and a small aperture (Vis-IR) and minimal shielding with a large aperture (ECH). The neutronics discrete-ordinates code ATTILA® and SEVERIAN® (the ATTILA parallel processing version) was used. Material properties and the 500 MW D-T volume source were taken from the ITER “Brand Model” MCNP benchmark model. A biased quadrature set equivelant to Sn=32 and a scattering degree of Pn=3 were used along with a 46-neutron and 21-gamma FENDL energy subgrouping. Total nuclear heating (neutron plug gamma heating) in the upper port plugs ranged between 380 and 350 kW for the Vis-IR and ECH cases. The ECH or Large Aperture model exhibited lower total heating but much higher peak volumetric heating on the upper port plug structure. Personnel dose rates are calculated in a three step process involving a neutron-only transport calculation, the generation of activation volume sources at pre-defined time steps and finally gamma transport analyses are run for selected time steps. ANSI-ANS 6.1.1 1977 Flux-to-Dose conversion factors were used. Dose rates were evaluated for 1 full year of 500 MW DT operation which is comprised of 3000 1800-second pulses. After one year the machine is shut down for maintenance and personnel are permitted to access the diagnostic interspace after 2-weeks if dose rates are below 100 μSv/hr. Dose rates in the Visible-IR diagnostic model after one day of shutdown were 130 μSv/hr but fell below the limit to 90 μSv/hr 2-weeks later. The Large Aperture or ECH style shielding model exhibited higher and more persistent dose rates. After 1-day the dose rate was 230

  3. Cosmic ray heliospheric transport study with neutron monitor data

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.; Ygbuhay, R. C.; Modzelewska, R.; Dorman, L. I.; Alania, M. V.

    2015-10-01

    Determining transport coefficients for galactic cosmic ray (GCR) propagation in the turbulent interplanetary magnetic field (IMF) poses a fundamental challenge in modeling cosmic ray modulation processes. GCR scattering in the solar wind involves wave-particle interaction, the waves being Alfven waves which propagate along the ambient field (B). Empirical values at 1 AU are determined for the components of the diffusion tensor for GCR propagation in the heliosphere using neutron monitor (NM) data. At high rigidities, particle density gradients and mean free paths at 1 AU in B can only be computed from the solar diurnal anisotropy (SDA) represented by a vector A (components Ar, Aϕ, and Aθ) in a heliospherical polar coordinate system. Long-term changes in SDA components of NMs (with long track record and the median rigidity of response Rm ~ 20 GV) are used to compute yearly values of the transport coefficients for 1963-2013. We confirm the previously reported result that the product of the parallel (to B) mean free path (λ||) and radial density gradient (Gr) computed from NM data exhibits a weak Schwabe cycle (11y) but strong Hale magnetic cycle (22y) dependence. Its value is most depressed in solar activity minima for positive (p) polarity intervals (solar magnetic field in the Northern Hemisphere points outward from the Sun) when GCRs drift from the polar regions toward the helioequatorial plane and out along the heliospheric current sheet (HCS), setting up a symmetric gradient Gθs pointing away from HCS. Gr drives all SDA components and λ|| Gr contributes to the diffusive component (Ad) of the ecliptic plane anisotropy (A). GCR transport is commonly discussed in terms of an isotropic hard sphere scattering (also known as billiard-ball scattering) in the solar wind plasma. We use it with a flat HCS model and the Ahluwalia-Dorman master equations to compute the coefficients α (=λ⊥/λ∥) and ωτ (a measure of turbulence in the solar wind) and transport

  4. Factors Affecting the Application of a Simple Ratio Technique for Spectral Correction of a Neutron Personnel Albedo Dosimeter.

    DTIC Science & Technology

    1983-11-01

    nY reaction (Ha79). The effect pof the Boron-lO pouch can be theoretically calculated for known spectra by using the Boron-lO neutron absorption cross section curve...14 MeV the 6LiF response curve can be appropriately approximated by utilizing the Lithium-6 neutron absorption cross section curve (Ga76,GI83

  5. The new Athens center on data processing from the neutron monitor network in real time

    NASA Astrophysics Data System (ADS)

    Mavromichalaki, H.; Souvatzoglou, G.; Sarlanis, C.; Mariatos, G.; Gerontidou, M.; Papaioannou, A.; Plainaki, C.; Tatsis, S.; Belov, A.; Eroshenko, E.; Yanke, V.

    2005-11-01

    The ground-based neutron monitors (NMs) record galactic and solar relativistic cosmic rays which can play a useful key role in space weather forecasting, as a result of their interaction with interplanetary disturbances. The Earth's-based neutron monitor network has been used in order to produce a real-time prediction of space weather phenomena. Therefore, the Athens Neutron Monitor Data Processing Center (ANMODAP) takes advantage of this unique multi-directional device to solve problems concerning the diagnosis and forecasting of space weather. At this moment there has been a multi-sided use of neutron monitors. On the one hand, a preliminary alert for ground level enhancements (GLEs) may be provided due to relativistic solar particles and can be registered around 20 to 30 min before the arrival of the main part of lower energy particles responsible for radiation hazard. To make a more reliable prognosis of these events, real time data from channels of lower energy particles and X-ray intensity from the GOES satellite are involved in the analysis. The other possibility is to search in real time for predictors of geomagnetic storms when they occur simultaneously with Forbush effects, using hourly, on-line accessible neutron monitor data from the worldwide network and applying a special method of processing. This chance of prognosis is only being elaborated and considered here as one of the possible uses of the Neutron Monitor Network for forecasting the arrival of interplanetary disturbance to the Earth. The achievements, the processes and the future results, are discussed in this work.

  6. New cathode design boron lined proportional counters for neutron area monitoring application

    NASA Astrophysics Data System (ADS)

    Dighe, Priyamvada M.

    2007-06-01

    A new cathode design boron lined proportional counter of 26 mm ID×100 mm sensitive length SS304 cathode has been developed with boron-coated baffles separated by 3 mm spacers inserted in the sensitive volume perpendicular to the axis. The baffles and the spacers were coated with indigenously available 27.7% enriched 10B. The introduction of baffles enhanced the boron coated surface area by a factor of 2.8. Tests in 120 nv thermal neutron flux show that the counter has 0.84 cps/nv thermal neutron sensitivity, which shows enhancement in the sensitivity by a factor of 2.78 due to baffle structure. For comparison standard cylindrical cathode geometry counter coated with 92% enriched 10B on its inner wall with a coating thickness of 0.8 mg/cm2 is developed with same outer dimensions for neutron area monitoring applications. The counter has 1 cps/nv thermal neutron sensitivity. Comparative tests carried out on counters with and without baffle structure show that the baffles enhance the neutron sensitivity and in 2 kR/h gamma background the effect of gamma pile up is similar on both the counters. The variation in cathode internal diameter due to baffle structure gives higher voltage plateau slope (2.8%/10 V) as compared to conventional cylindrical geometry counter (1.2%/10 V). The usability of boron lined counters for neutron area monitoring applications for the cylindrical geometry counter has been studied.

  7. Determination of barometric coefficients for total neutron intensity and neutron multiplicities on the base of Emilio Segre' Observatory data corrected for primary variations according to Rome neutron monitor data

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    By the barometric coefficients determined in a first approximation in the way from sea level to the place of stationary operation, we corrected for barometric effect the total neutron intensity and intensities of neutron multiplicities detected by a 6NM-64 neutron monitor installed inside the Emilio Segre' Israelo-Italian moving laboratory (Mt. Hermon, Israel, 2020 m a.s.l.). The period June-December 1998 was analysed. We compared the obtained results with the Rome 17NM-64 neutron monitor data and corrected the Emilio Segre' Observatory data for primary variations. We determined with high accuracy barometric coefficients for the total neutron monitor counting rate and for the intensities of detected neutron multiplicities m=1, m=2, m=3, m=4, m=5, m=6, m=7 and m≥8.

  8. Footprint Characteristics of Cosmic-Ray Neutron Sensors for Soil Moisture Monitoring

    NASA Astrophysics Data System (ADS)

    Schrön, Martin; Köhli, Markus; Zreda, Marek; Dietrich, Peter; Zacharias, Steffen

    2015-04-01

    Cosmic-ray neutron sensing is a unique and an increasingly accepted method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources are quickly mixed in a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights into probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact on calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  9. Footprint Characteristics of Cosmic-Ray Neutron Sensing for Soil Moisture Monitoring

    NASA Astrophysics Data System (ADS)

    Schrön, M.; Köhli, M.; Zreda, M. G.; Dietrich, P.; Zacharias, S.

    2014-12-01

    Cosmic-ray neutron sensing has become an increasingly accepted and unique method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources quickly mixes a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights to energy spectra, probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  10. Assessment of neutron monitoring of the TMI-2 core using the installed source range monitors

    SciTech Connect

    Baratta, A.J.; Wu, H.Y.; Bandini, B.R.; Fricke, V.R.; Eidam, G.R.

    1986-01-01

    A major uncertainty facing Three Mile Island Unit 2 (TMI-2) defueling efforts involved understanding the response of the source range monitor (SRM) to core conditions prior to defueling, to changing core conditions experienced during various defueling operations, and to hypothetical changes in core reactivity. Since the accident, the SRMs were observed to be reading more than two orders of magnitude higher than could be accounted for by estimates of the neutron source strengths in the core and the k/sub eff/ of the core. If these instruments were to be used as indicators of core status during the defueling, it was essential to understand this anomaly. This paper reports a series of analyses that showed the SRMs are in fact operating correctly and that the anomaly could be explained in terms of redistribution of fuel into the lower head of the pressure vessel. In addition, the authors analyzed a series of planned defueling operations and hypothetical reactivity changes. These analyses showed that the SRMs were insensitive as expected to minor changes in fuel distribution but would respond to changes in k/sub eff/ provided these changes resulted in values of k/sub eff/ close to 1.

  11. Applying the neutron scatter camera to treaty verification and warhead monitoring.

    SciTech Connect

    Cooper, Robert Lee; Gerling, Mark; Brennan, James S.; Mascarenhas, Nicholas; Mrowka, Stanley; Marleau, Peter

    2010-12-01

    The neutron scatter camera was originally developed for a range of SNM detection applications. We are now exploring the feasibility of applications in treaty verification and warhead monitoring using experimentation, maximum likelihood estimation method (MLEM), detector optimization, and MCNP-PoliMi simulations.

  12. Used fuel storage monitoring using novel 4He scintillation fast neutron detectors and neutron energy discrimination analysis

    NASA Astrophysics Data System (ADS)

    Kelley, Ryan P.

    With an increasing quantity of spent nuclear fuel being stored at power plants across the United States, the demand exists for a new method of cask monitoring. Certifying these casks for transportation and long-term storage is a unique dilemma: their sealed nature lends added security, but at the cost of requiring non-invasive measurement techniques to verify their contents. This research will design and develop a new method of passively scanning spent fuel casks using 4He scintillation detectors to make this process more accurate. 4He detectors are a relatively new technological development whose full capabilities have not yet been exploited. These detectors take advantage of the high 4He cross section for elastic scattering at fast neutron energies, particularly the resonance around 1 MeV. If one of these elastic scattering interactions occurs within the detector, the 4He nucleus takes energy from the incident neutron, then de-excites by scintillation. Photomultiplier Tubes (PMTs) at either end of the detector tube convert this emitted light into an electrical signal. The goal of this research is to use the neutron spectroscopy features of 4He scintillation detectors to maintain accountability of spent fuel in storage. This project will support spent fuel safeguards and the detection of fissile material, in order to minimize the risk of nuclear proliferation and terrorism.

  13. Responses of selected neutron monitors to cosmic radiation at aviation altitudes.

    PubMed

    Yasuda, Hiroshi; Yajima, Kazuaki; Sato, Tatsuhiko; Takada, Masashi; Nakamura, Takashi

    2009-06-01

    Cosmic radiation exposure of aircraft crew, which is generally evaluated by numerical simulations, should be verified by measurements. From the perspective of radiological protection, the most contributing radiation component at aviation altitude is neutrons. Measurements of cosmic neutrons, however, are difficult in a civilian aircraft because of the limitations of space and electricity; a small, battery-operated dosimeter is required whereas larger-size instruments are generally used to detect neutrons with a broad range of energy. We thus examined the applicability of relatively new transportable neutron monitors for use in an aircraft. They are (1) a conventional rem meter with a polyethylene moderator (NCN1), (2) an extended energy-range rem meter with a tungsten-powder mixed moderator (WENDI-II), and (3) a recoil-proton scintillation rem meter (PRESCILA). These monitors were installed onto the racks of a business jet aircraft that flew two times near Japan. Observed data were compared to model calculations using a PHITS-based Analytical Radiation Model in the Atmosphere (PARMA). Excellent agreement between measured and calculated values was found for the WENDI-II. The NCN1 showed approximately half of predicted values, which were lower than those expected from its response function. The observations made with PRESCILA showed much higher than expected values; which is attributable to the presence of cosmic-ray protons and muons. These results indicate that careful attention must be paid to the dosimetric properties of a detector employed for verification of cosmic neutron dose.

  14. Neutron Imager and Flux Monitor Based on Micro Channel Plates (MCP) in Electrostatic Mirror Configuration

    NASA Astrophysics Data System (ADS)

    Variale, V.

    In this paper, a new high transparency device based on MCP for the monitoring the flux and spatial profile of a neutron beam will be described. The assembly consists of a carbon foil with a 6Li deposit, placed in the beam, and a MCP equipped with a phosphor screen readout viewed by a CCD camera, placed outside the beam. Secondary emitted electrons (SEE) produced in the carbon foil by the alpha-particles and tritons from the 6Li+n reaction, are deflected to the MCP detector by means of an electrostatic mirror, suitably designed to preserve the spatial resolution. The conductive layer on the phosphor can be used for neutron counting, and to obtain time-of-flight information. A peculiar feature of this device is that the use of an electrostatic mirror minimizes the perturbation of the neutron beam, i.e. absorption and scattering. It can be used at existing time-of-flight (TOF) facilities, in particular at the n_TOF facility at CERN, for monitoring the flux and special profile of the neutron beam in the thermal and epithermal region. In this work, the device principle and design will be presented, together with the main features in terms of resolution and neutron detection efficiency.

  15. Development and application of CVD diamond detectors to 14 MeV neutron flux monitoring.

    PubMed

    Angelone, M; Pillon, M; Marinelli, M; Milani, E; Paoletti, A; Tucciarone, A; Pucella, G; Verona-Rinati, G

    2004-01-01

    CVD diamond is an interesting material for radiation detection, its atomic number (Z = 6) is close to that of soft tissues (Z = 7.1) and it can also work in harsh environments. Since many years CVD diamond films have been grown at the Faculty of Engineering, Rome 'Tor Vergata' University, and in 1998 a collaboration with ENEA Fusion Division was established to develop fast neutron monitors to be used in fusion tokamak environment. In this paper the first test of a 120 microm thick polycrystalline CVD diamond detector used for monitoring 14.7 MeV neutrons emission produced with the Frascati Neutron Generator (FNG) is reported. The detector operates in air and in pulse mode. The time irradiation profiles recorded with the CVD diamond detector were compared with those recorded by the standard monitors available at FNG (SSD, fission chamber, NE-213). Good stability and capability to operate in neutron flux up to 1.5 x 10(8) n cm(-2) s(-1) was observed. The radiation hardness property was also investigated using a 460 microm thick film and these results are also reported.

  16. The Cosmic Ray Nucleonic Component: The Invention and Scientific Uses of the Neutron Monitor - (Keynote Lecture)

    NASA Astrophysics Data System (ADS)

    Simpson, John A.

    2000-07-01

    The invention of the neutron monitor pile for the study of cosmic-ray intensity-time and energy changes began with the discovery in 1948 that the nucleonic component cascade in the atmosphere had a huge geomagnetic latitude dependence. For example, between 0° and 60° this dependence was a ˜ 200-400% effect - depending on altitude - thus opening the opportunity to measure the intensity changes in the arriving cosmic-ray nuclei down to ˜1-2 GeV nucl-1 for the first time. In these measurements the fast (high energy) neutron intensity was shown to be a surrogate for the nuclear cascade intensity in the atmosphere. The development of the neutron monitor in 1948-1951 and the first geomagnetic latitude network will be discussed. Among its early applications were: (1) to prove that there exists interplanetary solar modulation of galactic cosmic-rays (1952), and; (2) to provide the evidence for a dynamical heliosphere (1956). With the world-wide distribution of neutron monitor stations that are presently operating (˜ 50) many novel investigations are still to be carried out, especially in collaborations with spacecraft experiments.

  17. Monitoring the implementation of the WHO Global Code of Practice on the International Recruitment of Health Personnel

    PubMed Central

    Zurn, Pascal; Rø, Otto Christian; Gedik, Gulin; Ronquillo, Kenneth; Joan Co, Christine; Vaillancourt-Laflamme, Catherine; dela Rosa, Jennifer; Perfilieva, Galina; Dal Poz, Mario Roberto

    2013-01-01

    Abstract Objective To present the findings of the first round of monitoring of the global implementation of the WHO Global Code of Practice on the International Recruitment of Health Personnel (“the Code”), a voluntary code adopted in 2010 by all 193 Member States of the World Health Organization (WHO). Methods WHO requested that its Member States designate a national authority for facilitating information exchange on health personnel migration and the implementation of the Code. Each designated authority was then sent a cross-sectional survey with 15 questions on a range of topics pertaining to the 10 articles included in the Code. Findings A national authority was designated by 85 countries. Only 56 countries reported on the status of Code implementation. Of these, 37 had taken steps towards implementing the Code, primarily by engaging relevant stakeholders. In 90% of countries, migrant health professionals reportedly enjoy the same legal rights and responsibilities as domestically trained health personnel. In the context of the Code, cooperation in the area of health workforce development goes beyond migration-related issues. An international comparative information base on health workforce mobility is needed but can only be developed through a collaborative, multi-partnered approach. Conclusion Reporting on the implementation of the Code has been suboptimal in all but one WHO region. Greater collaboration among state and non-state actors is needed to raise awareness of the Code and reinforce its relevance as a potent framework for policy dialogue on ways to address the health workforce crisis. PMID:24347705

  18. Integration of Neutron Monitor Data with Spacecraft Observations: a Historical Perspective

    NASA Astrophysics Data System (ADS)

    McDonald, Frank B.

    2000-07-01

    Beginning in the early 1950s, data from neutron monitors placed the taxonomy of cosmic ray temporal variations on a firm footing, extended the observations of the Sun as a transient source of high energy particles and laid the foundation of our early concepts of a heliosphere. The first major impact of the arrival of the Space Age in 1957 on our understanding of cosmic rays came from spacecraft operating beyond the confines of our magnetosphere. These new observations showed that Forbush decreases were caused by interplanetary disturbances and not by changes in the geomagnetic field; the existence of both the predicted solar wind and interplanetary magnetic field was confirmed; the Sun was revealed as a frequent source of energetic ions and electrons in the 10 100 MeV range; and a number of new, low-energy particle populations was discovered. Neutron monitor data were of great value in interpreting many of these new results. With the launch of IMP 6 in 1971, followed by a number of other spacecraft, long-term monitoring of low and medium energy galactic and anomalous cosmic rays and solar and interplanetary energetic particles, and the interplanetary medium were available on a continuous basis. Many synoptic studies have been carried out using both neutron monitor and space observations. The data from the Pioneer 10/11 and Voyagers 1/2 deep space missions and the journey of Ulysses over the region of the solar poles have significantly extended our knowledge of the heliosphere and have provided enhanced understanding of many effects that were first identified in the neutron monitor data. Solar observations are a special area of space studies that has had great impact on interpreting results from neutron monitors, in particular the identification of coronal holes as the source of high-speed solar wind streams and the recognition of the importance of coronal mass ejections in producing interplanetary disturbances and accelerating solar energetic particles. In the

  19. A multi-detector neutron spectrometer with nearly isotropic response for environmental and workplace monitoring

    NASA Astrophysics Data System (ADS)

    Gómez-Ros, J. M.; Bedogni, R.; Moraleda, M.; Delgado, A.; Romero, A.; Esposito, A.

    2010-01-01

    This communication describes an improved design for a neutron spectrometer consisting of 6Li thermoluminescent dosemeters located at selected positions within a single moderating polyethylene sphere. The spatial arrangement of the dosemeters has been designed using the MCNPX Monte Carlo code to calculate the response matrix for 56 log-equidistant energies from 10 -9 to 100 MeV, looking for a configuration that permits to obtain a nearly isotropic response for neutrons in the energy range from thermal to 20 MeV. The feasibility of the proposed spectrometer and the isotropy of its response have been evaluated by simulating exposures to different reference and workplace neutron fields. The FRUIT code has been used for unfolding purposes. The results of the simulations as well as the experimental tests confirm the suitability of the prototype for environmental and workplace monitoring applications.

  20. Possible theoretical explanations for occasional days of non-field-aligned diffusion at neutron monitor energies

    NASA Technical Reports Server (NTRS)

    Forman, M. A.

    1975-01-01

    It has been shown previously (Anath et al., 1973 and Kane, 1974) that 20 to 25% of days, the diffusion component of the cosmic-ray neutron diurnal anisotropy is directed more than 30 degrees away from the ecliptic projection of the interplanetary magnetic field averaged over the same 24 hours. A number of explanations for this deviation are discussed and it is concluded that transverse gradient drifts due to gradients perpendicular to the ecliptic are likely, that diurnal variations in the diffusion component of the neutron anisotropy may affect results from single stations and that the 24 hour mean interplanetary magnetic field may not be the field appropriate to the streaming equation at neutron monitor energies.

  1. Calculation of neutron die-away times in a large-vehicle portal monitor

    SciTech Connect

    Lillie, R.A.; Santoro, R.T.; Alsmiller, R.G. Jr.

    1980-05-01

    Monte Carlo methods have been used to calculate neutron die-away times in a large-vehicle portal monitor. These calculations were performed to investigate the adequacy of using neutron die-away time measurements to detect the clandestine movement of shielded nuclear materials. The geometry consisted of a large tunnel lined with He/sup 3/ proportional counters. The time behavior of the (n,p) capture reaction in these counters was calculated when the tunnel contained a number of different tractor-trailer load configurations. Neutron die-away times obtained from weighted least squares fits to these data were compared. The change in neutron die-away time due to the replacement of cargo in a fully loaded truck with a spherical shell containing 240 kg of borated polyethylene was calculated to be less than 3%. This result together with the overall behavior of neutron die-away time versus mass inside the tunnel strongly suggested that measurements of this type will not provide a reliable means of detecting shielded nuclear materials in a large vehicle. 5 figures, 4 tables.

  2. Personnel Department Automation.

    ERIC Educational Resources Information Center

    Wilkinson, David

    In 1989, the Austin Independent School District's Office of Research and Evaluation was directed to monitor the automation of personnel information and processes in the district's Department of Personnel. Earlier, a study committee appointed by the Superintendent during the 1988-89 school year identified issues related to Personnel Department…

  3. Design and operation of a passive neutron monitor for assaying the TRU content of solid wastes

    SciTech Connect

    Brodzinski, R.L.; Brown, D.P.; Rieck, H.G. Jr.; Rogers, L.A.

    1984-02-01

    A passive neutron monitor has been designed and built for determining the residual transuranic (TRU) and plutonium content of chopped leached fuel hulls and other solid wastes from spent Fast Flux Test Facility (FFTF) fuel. The system was designed to measure as little as 8 g of plutonium or 88 mg of TRU in a waste package as large as a 208-l drum which could be emitting up to 220,000 R/hr of gamma radiation. For practical purposes, maximum assay times were chosen to be 10,000 sec. The monitor consists of 96 /sup 10/BF/sub 3/ neutron sensitive proportional counting tubes each 5.08 cm in diameter and 183 cm in active length. Tables of neutron emission rates from both spontaneous fission and (..cap alpha..,n) reactions on oxygen are given for all contributing isotopes expected to be present in spent FFTF fuel. Tables of neutron yeilds from isotopic compositions predicted for various exposures and cooling times are also given. Methods of data reduction and sources, magnitude, and control of errors are discussed. Backgrounds and efficiencies have been measured and are reported. A section describing step-by-step operational procedures is included. Guidelines and procedures for quality control and troubleshooting are also given. 13 references, 15 figures, 4 tables.

  4. Dependence of the neutron monitor count rate and time delay distribution on the rigidity spectrum of primary cosmic rays

    NASA Astrophysics Data System (ADS)

    Mangeard, P.-S.; Ruffolo, D.; Sáiz, A.; Nuntiyakul, W.; Bieber, J. W.; Clem, J.; Evenson, P.; Pyle, R.; Duldig, M. L.; Humble, J. E.

    2016-12-01

    Neutron monitors are the premier instruments for precisely tracking time variations in the Galactic cosmic ray flux at GeV-range energies above the geomagnetic cutoff at the location of measurement. Recently, a new capability has been developed to record and analyze the neutron time delay distribution (related to neutron multiplicity) to infer variations in the cosmic ray spectrum as well. In particular, from time delay histograms we can determine the leader fraction L, defined as the fraction of neutrons that did not follow a previous neutron detection in the same tube from the same atmospheric secondary particle. Using data taken during 2000-2007 by a shipborne neutron monitor latitude survey, we observe a strong dependence of the count rate and L on the geomagnetic cutoff. We have modeled this dependence using Monte Carlo simulations of cosmic ray interactions in the atmosphere and in the neutron monitor. We present new yield functions for the count rate of a neutron monitor at sea level. The simulation results show a variation of L with geomagnetic cutoff as observed by the latitude survey, confirming that these changes in L can be attributed to changes in the cosmic ray spectrum arriving at Earth's atmosphere. We also observe a variation in L with time at a fixed cutoff, which reflects the evolution of the cosmic ray spectrum with the sunspot cycle, known as solar modulation.

  5. Monitoring the latest stages of a transient neutron star X-ray binary

    NASA Astrophysics Data System (ADS)

    Campana, Sergio

    2012-10-01

    Neutron star transient low mass X-ray binaries (TLMXB) are among the brightest sources in the X-ray sky. Their outbursts are well known and studied. Despite this, their return to quiescence has been studied only in a handful of cases. This return is quite fast making even more difficult. Recently we monitor in high detail the return to quiescence of the archetypal TLMXB Aql X-1 thanks to XMM-Newton observations. We probed for the first time the cooling of the neutron star after a (short) outburst, finding a very short cooling time ( 3d). Thanks to an approved Swift XRT program for monitoring every day for 5 ks (for 30 d) the latest stages of a TLMXB, we are aiming assessing the spectral properties of a transient LMXB close to the quiescent level.

  6. 1987 Neutron and gamma personnel dosimeter intercomparison study using a D/sub 2/O-moderated /sup 252/Cf source

    SciTech Connect

    Swaja, R.E.; West, L.E.; Sims, C.S.; Welty, T.J.

    1989-05-01

    The thirteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 13) was conducted during April 1987 as a joint effort by Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Group and the Southwest Radiation Calibration Center at the University of Arkansas. A total of 48 organizations (34 from the US and 14 from abroad) participated in PDIS 13. Participants submitted a total of 1,113 neutron and gamma dosimeters for this mixed field study. The dosimeters were transferred by mail and were handled by experimental personnel at ORNL and the University of Arkansas. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (49%), direct interaction TLD (31%), CR-39 (17%), film (3%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: Li/sub 2/B/sub 4/O/sub 7/, alone or in combination with CaSO/sub 4/, (69%), /sup 7/LiF (28%), natural LiF (3%). Radiation exposures in PDIS 13 were limited to 0.5 and 1.5 mSv from /sup 252/Cf moderated by 15-cm of D/sub 2/O. Traditional exposures using the Health Physics Research Reactor (HPRR) were not possible due to the fact that all reactors at ORNL, including the HPRR, were shutdown by order of the Department of Energy at the time the intercomparison was performed. Planned exposures using a /sup 238/PuBe source were negated by a faulty timing mechanism. Based on accuracy and precision, direct interaction TLD dosimeters exhibited the best performance in PDIS 13 neutron measurements. They were followed, in order of best performance, by CR-39, TLD albedo, and film. The Li/sub 2/B/sub 4/O/sub 7/ type TLD dosimeters exhibited the best performance in PDIS 13 gamma measurements. They were followed by natural LiF, /sup 7/LiF, and film. 12 refs., 1 fig., 5 tabs.

  7. Analysis of the Ground-Level Enhancements on 14 July 2000 and 13 December 2006 Using Neutron Monitor Data

    NASA Astrophysics Data System (ADS)

    Mishev, A.; Usoskin, I.

    2016-04-01

    On the basis of neutron monitor data, we estimate the energy spectrum, anisotropy axis direction, and pitch-angle distribution of solar energetic particles during two major ground-level enhancements (GLE 59 on 14 July 2000 and GLE 70 on 13 December 2006). For the analysis we used a newly computed neutron monitor yield function. The method consists of several consecutive steps: definition of the asymptotic viewing cones of neutron monitor stations considered for the data analysis by computing the cosmic ray particle propagation in a model magnetosphere with the MAGNETOCOSMICS code, computing the neutron monitor model responses, and deriving the solar energetic particle characteristics on the basis of inverse problem solution. The pitch-angle distribution and rigidity spectrum of high-energy protons are obtained as a function of time in the course of ground-level enhancements. A comparison with previously reported results is performed and reasonable agreement is achieved. A discussion of the obtained results is included.

  8. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    DOEpatents

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  9. Study of the triton-burnup process in different JET scenarios using neutron monitor based on CVD diamond

    NASA Astrophysics Data System (ADS)

    Nemtsev, G.; Amosov, V.; Meshchaninov, S.; Popovichev, S.; Rodionov, R.

    2016-11-01

    We present the results of analysis of triton burn-up process using the data from diamond detector. Neutron monitor based on CVD diamond was installed in JET torus hall close to the plasma center. We measure the part of 14 MeV neutrons in scenarios where plasma current varies in a range of 1-3 MA. In this experiment diamond neutron monitor was also able to detect strong gamma bursts produced by runaway electrons arising during the disruptions. We can conclude that CVD diamond detector will contribute to the study of fast particles confinement and help predict the disruption events in future tokamaks.

  10. Assisted living nursing practice: medication management: part 2 supervision and monitoring of medication administration by unlicensed assistive personnel.

    PubMed

    Mitty, Ethel; Flores, Sandi

    2007-01-01

    More than half the states permit assistance with or administration of medications by unlicensed assistive personnel or med techs. Authorization of this nursing activity (or task) is more likely because of state assisted living regulation than by support and approval of the state Board of Nursing. In many states, the definition of "assistance with" reads exactly like "administration of" thereby raising concern with regard to delegation, accountability, and liability for practice. It is, as well, a hazardous path for the assisted living nurse who must monitor and evaluate the performance of the individual performing this nursing task. This article, the second in a series on medication management, addresses delegation, standards of practice of medication administration, types of medication errors, the components of a performance evaluation tool, and a culture of safety. Maintaining professional standards of assisted living nursing practice courses throughout the suggested recommendations.

  11. Neutron spectrometry with Bonner Spheres for area monitoring in particle accelerators.

    PubMed

    Bedogni, Roberto

    2011-07-01

    Selecting the instruments to determine the operational quantities in the neutron fields produced by particle accelerators involves a combination of aspects, which is peculiar to these environments: the energy distribution of the neutron field, the continuous or pulsed time structure of the beam, the presence of other radiations to which the neutron instruments could have significant response and the large variability in the dose rate, which can be observed when moving from areas near the beam line to free-access areas. The use of spectrometric techniques in support of traditional instruments is highly recommended to improve the accuracy of dosimetric evaluations. The multi-sphere or Bonner Sphere Spectrometer (BSS) is certainly the most used device, due to characteristics such as the wide energy range, large variety of active and passive detectors suited for different workplaces, good photon discrimination and the simple signal management. Disadvantages are the poor energy resolution, weight and need to sequentially irradiate the spheres, leading to usually long measurement sessions. Moreover, complex unfolding analyses are needed to obtain the neutron spectra. This work is an overview of the BSS for area monitoring in particle accelerators.

  12. An investigation into the accuracy of the albedo dosimeter DVGN-01 in measuring personnel irradiation doses in the fields of neutron radiation at nuclear power installations of the joint institute for nuclear research

    NASA Astrophysics Data System (ADS)

    Beskrovnaya, L. G.; Goroshkova, E. A.; Mokrov, Yu. V.

    2010-05-01

    The calculated results of research into the accuracy of an individual albedo dosimeter DVGN-01 as it corresponds to the personal equivalent dose for neutrons H p (10) and to the effective dose for neutrons E eff in the neutron fields at Joint Institute for Nuclear Research Nuclear Power Installations (JNPI) upon different geometries of irradiations are presented. It has been shown that correction coefficients are required for the specific estimation of doses by the dosimeter. These coefficients were calculated using the energy sensitivity curve of the dosimeter and the known neutron spectra at JNPI. By using the correction factors, the uncertainties of both doses will not exceed the limits given to the personnel according to the standards.

  13. Applications and usage of the real-time Neutron Monitor Database

    NASA Astrophysics Data System (ADS)

    Mavromichalaki, H.; Papaioannou, A.; Plainaki, C.; Sarlanis, C.; Souvatzoglou, G.; Gerontidou, M.; Papailiou, M.; Eroshenko, E.; Belov, A.; Yanke, V.; Flückiger, E. O.; Bütikofer, R.; Parisi, M.; Storini, M.; Klein, K.-L.; Fuller, N.; Steigies, C. T.; Rother, O. M.; Heber, B.; Wimmer-Schweingruber, R. F.; Kudela, K.; Strharsky, I.; Langer, R.; Usoskin, I.; Ibragimov, A.; Chilingaryan, A.; Hovsepyan, G.; Reymers, A.; Yeghikyan, A.; Kryakunova, O.; Dryn, E.; Nikolayevskiy, N.; Dorman, L.; Pustil'Nik, L.

    2011-06-01

    A high-time resolution Neutron Monitor Database (NMDB) has started to be realized in the frame of the Seventh Framework Programme of the European Commission. This database will include cosmic ray data from at least 18 neutron monitors distributed around the world and operated in real-time. The implementation of the NMDB will provide the opportunity for several research applications most of which will be realized in real-time mode. An important one will be the establishment of an Alert signal when dangerous solar cosmic ray particles are heading to the Earth, resulting into ground level enhancements effects registered by neutron monitors. Furthermore, on the basis of these events analysis, the mapping of all ground level enhancement features in near real-time mode will provide an overall picture of these phenomena and will be used as an input for the calculation of the ionization of the atmosphere. The latter will be useful together with other contributions to radiation dose calculations within the atmosphere at several altitudes and will reveal the absorbed doses during flights. Moreover, special algorithms for anisotropy and pitch angle distribution of solar cosmic rays, which have been developed over the years, will also be set online offering the advantage to give information about the conditions of the interplanetary space. All of the applications will serve the needs of the modern world which relies at space environment and will use the extensive network of neutron monitors as a multi-directional spectrographic detector. On top of which, the decreases of the cosmic ray intensity - known as Forbush decreases - will also be analyzed and a number of important parameters such as galactic cosmic ray anisotropy will be made available to the users of NMDB. A part of the NMDB project is also dedicated to the creation of a public outreach website with the scope to inform about cosmic rays and their possible effects on humans, technological systems and space

  14. Analysis of the ambient dose variation due to cosmic rays in Daejeon by using a neutron monitor

    NASA Astrophysics Data System (ADS)

    Kim, Yun Ho; Kang, Jeongsoo; Jang, Doh-Yun; Son, Jae Bum; Kim, Yong-Kyun; Kim, Sung Joong

    2013-12-01

    The Basic Atomic Energy Research Institute of Hanyang University in Korea has constructed a cosmic-ray detection system that is presently being operated. In this study, the impact of cosmic-rays on 18-tube NM64-type neutron monitor installed in Daejeon was confirmed for the first time. In order to evaluate the reliability of the neutron monitor, we predicted the count rates from the neutron flux by using the Excel-based Program for calculating Atmospheric Cosmic-ray Spectrum (EXPACS); these predictions were then compared with experimental results. The predictions agree well with the results, with differences no greater than 3.95%. Also, changes in the neutron ambient dose equivalent rate from cosmic rays due to different environmental conditions were analyzed using EXPACS; the results obtained were compared with those of previous studies and were thus, confirmed to be reliable, suggesting that the detection system is suitable for making the relevant measurements. That detection system was then used to evaluate the neutron ambient dose equivalent rate for various environmental conditions in Daejeon. Finally, a conversion coefficient, defined as the ratio of counts from the neutron monitor to the neutron ambient dose equivalent, was obtained and included considerations of the impacts of geological factors and of meteorological factors of relative humidity and atmospheric depth. The derived formula fit the source data with an adjusted coefficient of determination ( R 2) of 0.9894 and a root-mean-square error of 1.7056 × 10-10, equivalent to about 1%. This confirmed satisfactory accuracy and reliability of the formula, thereby showing this methodology to be legitimate for use in evaluating the neutron ambient dose equivalent by using the Daejeon neutron monitor.

  15. Environmental assessment and planning at Mound - environmental monitoring capabilities and personnel profiles

    SciTech Connect

    1996-07-01

    Through its long experience with radioactive materials, Mound has developed a comprehensive, routine, offsite, environmental surveillance program to safeguard its employees, the physical plant, and the integrity of the surrounding environment from any potential adverse effects of its widely diverse operations. Effluent samples are analyzed for radiological and non-radiological parameters. The environment surrounding Mound Facility is continuously monitored - air, water, foodstuffs, vegetation, soil, and silt samples are analyzed to ensure that radioisotopic concentrations and other possible pollutants are well within the stringent standards adopted by the Department of Energy, the Environmental Protection Agencies (both federal and state), and various regional and local agencies. Moreover, this environmental surveillance program has been designed to ensure that the facility is designed, constructed, managed, operated, and maintained in a manner that continues to meet all federal, state, and local standards for environmental protection. Work in environmental science has been broadened to assess environmental factors associated with various aspects of the National Energy Plan. Both the management and staff at Mound have undertaken a firm commitment to make Mound`s environmental monitoring capabilities available to agencies that have the responsibility for the resolution of important environmental issues.

  16. Mini neutron monitor measurements at the Neumayer III station and on the German research vessel Polarstern

    NASA Astrophysics Data System (ADS)

    Heber, B.; Galsdorf, D.; Herbst, K.; Gieseler, J.; Labrenz, J.; Schwerdt, C.; Walter, M.; Benadé, G.; Fuchs, R.; Krüger, H.; Moraal, H.

    2015-08-01

    Neutron monitors (NMs) are ground-based devices to measure the variation of cosmic ray intensities, and although being reliable they have two disadvantages: their size as well as their weight. As consequence, [1] suggested the development of a portable, and thus much smaller and lighter, calibration neutron monitor that can be carried to any existing station around the world [see 2; 3]. But this mini neutron monitor, moreover, can also be installed as an autonomous station at any location that provides ’’office” conditions such as a) temperatures within the range of around 0 to less than 40 degree C as well as b) internet and c) power supply. However, the best location is when the material above the NM is minimized. In 2011 a mini Neutron Monitor was installed at the Neumayer III station in Antarctica as well as the German research vessel Polarstern, providing scientific data since January 2014 and October 2012, respectively. The Polarstern, which is in the possession of the Federal Republic of Germany represented by the Ministry of Education and Research and operated by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research and managed by the shipping company Laeisz, was specially designed for working in the polar seas and is currently one of the most sophisticated polar research vessels worldwide. It spends almost 310 days a year at sea usually being located in the waters of Antarctica between November and March while spending the northern summer months in Arctic waters. Therefore, the vessel scans the rigidity range below the atmospheric threshold and above 10 GV twice a year. In contrast to spacecraft measurements NM data are influenced by variations of the geomagnetic field as well as the atmospheric conditions. Thus, in order to interpret the data a detailed knowledge of the instrument sensitivity with geomagnetic latitude (rigidity) and atmospheric pressure is essential. In order to determine the atmospheric response data from the

  17. Deriving the properties of relativistic SEPs by using neutron monitor data

    NASA Astrophysics Data System (ADS)

    Plainaki, Christina; Laurenza, Monica; Mavromichalaki, Helen; Storini, Marisa; Gerontidou, Maria; Kanellakopoulos, Anastasios

    2014-05-01

    Ground Level Enhancements (GLEs), observed in cosmic ray intensity records of ground-based particle detectors, are related to the most energetic class of solar energetic particle (SEP) events, being them associated with both solar flares and coronal mass ejections (CMEs) and requiring acceleration processes that produce particles with energies ≥~500 MeV/part. upon entry in the Earth's atmosphere. The Neutron Monitor Based Anisotropic GLE Pure Power Law (NMBANGLE PPOLA) model (Plainaki et al. 2010), is an effective modeling tool that treats the neutron monitor network as an integrated omnidirectional spectrometer able to measure the characteristics of the relativistic primary solar proton flux, at some point of the near-Earth magnetosphere. In this context, modeling of the neutron monitor response to an anisotropic SCR flux, registered during a GLE event, and solving the inverse problem, can provide the actual characteristics of the relativistic SEPs that are responsible for the event. In this work, we apply the NMBANGLE PPOLA model to the recent GLE of 2012 May 17 (also known as GLE71). Our results are summarized as follows: (i) the SEP spectrum related to GLE71 was rather soft during the whole duration of the event, manifesting some weak acceleration episodes only during the initial phase (at ~ 01:55-02:00 UT) and at ~02:30-02:35 UT and ~02:55-03:00 UT; (ii) the spectral index of the modeled SEP spectrum supports the CME-shock driven particle acceleration scenario, in agreement with past results based on the analysis of satellite measurements; (iii) during the very initial phase of GLE71, the solar proton source at the top of the atmosphere was located above the northern hemisphere, implying that the asymptotic directions of viewing of the northern hemisphere NMs were more favourably located for registering the event than the southern ones; (iv) the spatial distribution of the solar proton fluxes at the top of the atmosphere, during the main phase manifested a

  18. Rhodium self-powered neutron detector as a suitable on-line thermal neutron flux monitor in BNCT treatments

    SciTech Connect

    Miller, Marcelo E.; Sztejnberg, Manuel L.; Gonzalez, Sara J.; Thorp, Silvia I.; Longhino, Juan M.; Estryk, Guillermo

    2011-12-15

    Purpose: A rhodium self-powered neutron detector (Rh SPND) has been specifically developed by the Comision Nacional de Energia Atomica (CNEA) of Argentina to measure locally and in real time thermal neutron fluxes in patients treated with boron neutron capture therapy (BNCT). In this work, the thermal and epithermal neutron response of the Rh SPND was evaluated by studying the detector response to two different reactor spectra. In addition, during clinical trials of the BNCT Project of the CNEA, on-line neutron flux measurements using the specially designed detector were assessed. Methods: The first calibration of the detector was done with the well-thermalized neutron spectrum of the CNEA RA-3 reactor thermal column. For this purpose, the reactor spectrum was approximated by a Maxwell-Boltzmann distribution in the thermal energy range. The second calibration was done at different positions along the central axis of a water-filled cylindrical phantom, placed in the mixed thermal-epithermal neutron beam of CNEA RA-6 reactor. In this latter case, the RA-6 neutron spectrum had been well characterized by both calculation and measurement, and it presented some marked differences with the ideal spectrum considered for SPND calibrations at RA-3. In addition, the RA-6 neutron spectrum varied with depth in the water phantom and thus the percentage of the epithermal contribution to the total neutron flux changed at each measurement location. Local (one point-position) and global (several points-positions) and thermal and mixed-field thermal neutron sensitivities were determined from these measurements. Thermal neutron flux was also measured during BNCT clinical trials within the irradiation fields incident on the patients. In order to achieve this, the detector was placed on patient's skin at dosimetric reference points for each one of the fields. System stability was adequate for this kind of measurement. Results: Local mixed-field thermal neutron sensitivities and global

  19. Implementation and Impact of an Automated Group Monitoring and Feedback System to Promote Hand Hygiene Among Health Care Personnel

    PubMed Central

    Conway, Laurie J.; Riley, Linda; Saiman, Lisa; Cohen, Bevin; Alper, Paul; Larson, Elaine L.

    2015-01-01

    Article-at-a-Glance Background Despite substantial evidence to support the effectiveness of hand hygiene for preventing health care–associated infections, hand hygiene practice is often inadequate. Hand hygiene product dispensers that can electronically capture hand hygiene events have the potential to improve hand hygiene performance. A study on an automated group monitoring and feedback system was implemented from January 2012 through March 2013 at a 140-bed community hospital. Methods An electronic system that monitors the use of sanitizer and soap but does not identify individual health care personnel was used to calculate hand hygiene events per patient-hour for each of eight inpatient units and hand hygiene events per patient-visit for the six outpatient units. Hand hygiene was monitored but feedback was not provided during a six-month baseline period and three-month rollout period. During the rollout, focus groups were conducted to determine preferences for feedback frequency and format. During the six-month intervention period, graphical reports were e-mailed monthly to all managers and administrators, and focus groups were repeated. Results After the feedback began, hand hygiene increased on average by 0.17 events/patient-hour in inpatient units (interquartile range = 0.14, p = .008). In outpatient units, hand hygiene performance did not change significantly. A variety of challenges were encountered, including obtaining accurate census and staffing data, engendering confidence in the system, disseminating information in the reports, and using the data to drive improvement. Conclusions Feedback via an automated system was associated with improved hand hygiene performance in the short term. PMID:25252389

  20. Application of magnetomechanical hysteresis modeling of magnetic techniques for monitoring neutron embrittlement and biaxial stress

    SciTech Connect

    Sablik, M.J.; Kwun, H.; Burkhardt, G.L.; Rollwitz, W.L.; Cadena, D.G.

    1993-01-31

    Objective of this project is to investigate experimentally and theoretically the effects of neutron embrittlement and biaxial stress on magnetic properties in steels, using various magnetic measurement techniques. If neutron embrittlement and biaxial stress can be measured via changes in magnetic properties, this should ultimately assist in safety monitoring of nuclear power plants and of gas and oil pipelines. This first-year report addresses the issue of using magnetic property changes to detect neutron embrittlement. The magnetic measurements were all done on irradiated specimens previously broken in two in a Charpy test to determine their embrittlement. The magnetic properties of the broken charpy specimens from D.C. Cook did not correlate well with fluence or embrittlement parameters, possible due to metallurgical reasons. correlation was better with Indian Point 2 specimens, with the nonlinear harmonic amplitudes showing the best correlation (R[sup 2][approximately]0.7). However, correlation was not good enough. It is recommended that tests be done on unbroken irradiated Charpy specimens, for which magnetic characterization data prior to irradiation is available, if possible.

  1. Optimising the neutron environment of Radiation Portal Monitors: A computational study

    NASA Astrophysics Data System (ADS)

    Gilbert, Mark R.; Ghani, Zamir; McMillan, John E.; Packer, Lee W.

    2015-09-01

    Efficient and reliable detection of radiological or nuclear threats is a crucial part of national and international efforts to prevent terrorist activities. Radiation Portal Monitors (RPMs), which are deployed worldwide, are intended to interdict smuggled fissile material by detecting emissions of neutrons and gamma rays. However, considering the range and variety of threat sources, vehicular and shielding scenarios, and that only a small signature is present, it is important that the design of the RPMs allows these signatures to be accurately differentiated from the environmental background. Using Monte-Carlo neutron-transport simulations of a model 3He detector system we have conducted a parameter study to identify the optimum combination of detector shielding, moderation, and collimation that maximises the sensitivity of neutron-sensitive RPMs. These structures, which could be simply and cost-effectively added to existing RPMs, can improve the detector response by more than a factor of two relative to an unmodified, bare design. Furthermore, optimisation of the air gap surrounding the helium tubes also improves detector efficiency.

  2. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

    NASA Astrophysics Data System (ADS)

    Geslot, B.; Vermeeren, L.; Filliatre, P.; Lopez, A. Legrand; Barbot, L.; Jammes, C.; Bréaud, S.; Oriol, L.; Villard, J.-F.

    2011-03-01

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 × 1020 n/cm2. A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  3. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

    SciTech Connect

    Geslot, B.; Filliatre, P.; Barbot, L.; Jammes, C.; Breaud, S.; Oriol, L.; Villard, J.-F.; Lopez, A. Legrand

    2011-03-15

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 x 10{sup 20} n/cm{sup 2}. A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  4. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions.

    PubMed

    Geslot, B; Vermeeren, L; Filliatre, P; Lopez, A Legrand; Barbot, L; Jammes, C; Bréaud, S; Oriol, L; Villard, J-F

    2011-03-01

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 × 10(20) n∕cm(2). A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  5. Characteristics of cosmic ray pole-equator anisotropy derived from spherical harmonic analysis of neutron monitor data

    NASA Technical Reports Server (NTRS)

    Takahashi, H.; Yahagi, N.

    1985-01-01

    The spherical harmonic analysis of cosmic ray neutron data from the worldwide network neutron monitor stations during the years, 1966 to 1969 was carried out. The second zonal harmonic component obtained from the analysis corresponds to the Pole-Equator anisotropy of the cosmic ray neutron intensity. Such an anisotropy makes a semiannual variation. In addition to this, it is shown that the Pole-Equator anisotropy makes a variation depending on the interplanetary magnetic field (IMF) sector polarities around the passages of the IMF sector boundary. A mechanism to interpret these results is also discussed.

  6. In-situ monitoring the realkalisation process by neutron diffraction: Electroosmotic flux and portlandite formation

    SciTech Connect

    Castellote, Marta . E-mail: martaca@ietcc.csic.es; Llorente, Irene; Andrade, Carmen; Turrillas, Xavier; Alonso, Cruz; Campo, Javier

    2006-05-15

    Even though the electroosmotic flux through hardened cementitious materials during laboratory realkalisation trials had been previously noticed, it has never been in-situ monitored, analysing at the same time the establishment of the electroosmotic flux and the microstructure changes in the surroundings of the rebar. In this paper, two series of cement pastes, cast with CEM I and CEM I substituted in a 35% by fly ash, previously carbonated at 100% CO{sub 2}, were submitted to realkalisation treatments followed on line by simultaneous acquisition of neutron diffraction data. As a result, it has been possible to confirm the electroosmosis as the driving force of carbonates towards the rebar and to determine the range of pH in the anolyte in which most of the relevant electroosmotic phenomena takes place. On the other hand, the behaviour of the main crystalline phases involved in the process has been monitored during the treatment, with the precipitation of portlandite as main result.

  7. Simulation of the temporal variations of the galactic cosmic-ray intensity at neutron monitor energies

    NASA Astrophysics Data System (ADS)

    Exarhos, G.; Moussas, X.

    2001-05-01

    We show that the temporal variations of the integrated galactic cosmic-ray intensity at neutron monitor energies (approximately above 3 GeV) can be reproduced applying a semi-empirical 1-D diffusion-convection model for the cosmic-ray transport in interplanetary space. We divide the interplanetary region into `magnetic shells' and find the relative reduction that each shell causes to the cosmic-ray intensity. Then the cosmic-ray intensity at the Earth is reproduced by the successive influence of all shells between the Earth and the heliospheric termination shock. We find that the position of the termination shock does not significantly affect the cosmic-ray intensity although there are some differences between the results for a constant and a variable termination shock radius. We also reproduce the cosmic-ray intensity applying the analytical solution of the force-field approximation (Perko, 1987) and find that the results cannot fit the observed data. Our results are compared with the Climax (geomagnetic cut-off ~ 3 GV) and Huancayo (geomagnetic cut-off ~ 13 GV) neutron monitor measurements for almost two solar cycles (1976-1996).

  8. An estimation of the yield and response functions for the mini neutron monitor

    NASA Astrophysics Data System (ADS)

    Caballero-Lopez, R. A.

    2016-08-01

    The present study estimates the yield and response functions of the mini neutron monitor (miniNM). This relatively new cosmic ray detector is the mobile version of the standard NM64. It can be use not only to calibrate the NM64 but also to study the modulation processes. Due to its portability, the miniNM can be easily placed in a suitable location to measure secondary particles, which give information about the intensity variations of galactic and solar cosmic rays. In order to perform these modulation studies with miniNMs, it is crucial to know their sensitivity to detect secondary cosmic ray flux, i.e., we must know their yield function. A previous study found that miniNM and NM64 have slightly different response functions. This work analyzes the observed counting rate ratio (miniNM to NM64) and gives for the first time an useful expression for the yield function of the miniNM. The results found here will allow to interpret the new measurements with this mobile neutron monitor. For comparison, a brief summary of the NM64 yield functions reported by other authors is presented.

  9. In vivo monitoring of toxic metals: assessment of neutron activation and x-ray fluorescence techniques

    SciTech Connect

    Ellis, K.J.

    1986-01-01

    To date, cadmium, lead, aluminum, and mercury have been measured in vivo in humans. The possibilities of monitoring other toxic metals have also been demonstrated, but no human studies have been performed. Neutron activation analysis appears to be most suitable for Cd and Al measurements, while x-ray fluorescence is ideally suited for measurement of lead in superficial bone. Filtered neutron beams and polarized x-ray sources are being developed which will improve in vivo detection limits. Even so, several of the current facilities are already suitable for use in epidemiological studies of selected populations with suspected long-term low-level ''environmental'' exposures. Evaluation and diagnosis of patients presenting with general clinical symptoms attributable to possible toxic metal exposure may be assisted by in vivo examination. Continued in vivo monitoring of industrial workers, especially follow-up measurements, will provide the first direct assessment of changes in body burden and a direct measure of the biological life-times of these metals in humans. 50 refs., 4 figs., 2 tabs.

  10. Thunderstorms' atmospheric electric field effects in the intensity of cosmic ray muons and in neutron monitor data

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Dorman, I. V.; Iucci, N.; Parisi, M.; Ne'Eman, Y.; Pustil'Nik, L. A.; Signoretti, F.; Sternlieb, A.; Villoresi, G.; Zukerman, I. G.

    2003-05-01

    Theoretical and experimental results on the influence of thunderstorms' atmospheric electric field on cosmic ray secondary components are presented. On the basis of the approach proposed by [1987], theoretical models for a correct numerical evaluation of these effects on hard muon, soft muon, and neutron monitor component are developed. For hard and soft muons the validity of the models are checked by their comparison with experimental results of the Baksan muon detector. For the first time, the effect of thunderstorms' atmospheric electric field on cosmic rays is investigated by simultaneous measurements of one-minute neutron monitor intensity and of atmospheric electric field at the Emilio Segre' Observatory on Mt. Hermon (Israel). A series of large thunderstorms during February 2000 is investigated; for each thunderstorm the maximum atmospheric electric field intensity was ranging from 10 to about 100 kV/m. Clear correlation between field intensity and neutron monitor intensity variations is presented for total intensity and for different detected multiplicity channels. This correlation is quantitatively in agreement with the developed model which takes into account the formation of short-living meso-atoms by the capture of slow negative muons in the lead of the monitor. The effect is relevant only for neutron events with detected multiplicity m = 1 and evident for multiplicity m = 2; the other multiplicity channels are not influenced by neutrons from meso-atoms.

  11. Measurement result of the neutron monitor onboard Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP)

    NASA Astrophysics Data System (ADS)

    Koga, K.; Matsumoto, H.; Okudaira, O.; Obara, T.; Yamamoto, T.; Muraki, Y.

    2011-12-01

    To support future space activities, it is very important to acquire the space environmental data which causes the degradation of space parts and spacecraft anomalies. Such data are useful for spacecraft design and manned space activity. Space Environment Data Acquisition - Attached Payload (SEDA-AP) measures the space environment around the International Space Station (ISS) by being attached to the Exposed Facility(EF) of the Japanese Experimental Module ("Kibo"). The Neutron Monitor (NEM) is one of the detectors in SEDA-AP. This instrument was developed to measure the solar neutrons which are produced by solar flare event. The solar neutron is a good indicator to clarify the acceleration mechanism of charged particles at the solar flare. Because of the energy of solar neutron is not influenced by the interplanetary magnetic field, it has the information of the energy of the accelerated charged particle directly. We have been analyzing the neutron data at several M or X class solar flare from September 2009. The mission objectives, instrumentation and measurement status of the neutron monitor are reported.

  12. Forbush effects in total neutron monitor counting rate and neutron multiplicities recorded by the 6NM-64 of the E. Segre' Observatory at 2025 m and by the Rome 17NM-64

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    We show some Forbush-decrease events by using 5-minute and 1-hourly data of total neutron monitor counting rate and of detected neutron multiplicities according to observations by the Emilio Segre' Observatory 6NM-64 at the height of 2025 m (Rc=10.8 GV) and by the Rome 17NM-64 neutron monitor (Rc=6.2 GV). By these data it is possible in principle to evaluate approximately the cosmic ray primary variations for each Forbush-decrease (by using the method of coupling functions); also the detected neutron multiplicities can provide additional important information.

  13. Study and presentation of a fast neutron and photon dosemeter for area and criticality monitoring using radiophotoluminescent glass.

    PubMed

    Girod, M; Bourgois, L; Cornillaux, G; Andre, S; Postaük, J

    2004-01-01

    This paper describes the results of a study performed on a mixed field neutron/gamma (n/gamma) area dosemeter incorporating radiophotoluminescent (RPL) glass detectors. RPL glass is known to be virtually insensitive to neutrons. The aim of the study was therefore to determine the neutron response of a dosemeter designed to combine n/gamma conversion with RPL detection capability. Monte Carlo calculations as well as measurements using monoenergetic beams and isotopic neutron sources showed this response to be constant, to within 30% in terms of H*(10), and independent of neutron energy from 250 keV to 10 MeV. For area monitoring, tests carried out in nuclear facilities (around PuO2 glove box and shipping casks containing PWR, MOX spent fuels or vitrified fission product) demonstrated that dosemeter response was accurate to within 15%, where the gamma component of the mixed n,gamma field remained below 1 MeV. When exposed in the Silene reactor simulating a criticality accident (10(17) fissions-liquid 235U--e.g. 1 Gy neutron and 1 Gy photon), the dosemeter exhibited good correlation with reference values and other measurement technologies (again to within 30%), for both neutron and gamma absorbed dose.

  14. Application of the new neutron monitor yield function computed for different altitudes to an analysis of GLEs

    NASA Astrophysics Data System (ADS)

    Mishev, Alexander; Usoskin, Ilya

    2016-07-01

    A precise analysis of SEP (solar energetic particle) spectral and angular characteristics using neutron monitor (NM) data requires realistic modeling of propagation of those particles in the Earth's magnetosphere and atmosphere. On the basis of the method including a sequence of consecutive steps, namely a detailed computation of the SEP assymptotic cones of acceptance, and application of a neutron monitor yield function and convenient optimization procedure, we derived the rigidity spectra and anisotropy characteristics of several major GLEs. Here we present several major GLEs of the solar cycle 23: the Bastille day event on 14 July 2000 (GLE 59), GLE 69 on 20 January 2005, and GLE 70 on 13 December 2006. The SEP spectra and pitch angle distributions were computed in their dynamical development. For the computation we use the newly computed yield function of the standard 6NM64 neutron monitor for primary proton and alpha CR nuclei. In addition, we present new computations of NM yield function for the altitudes of 3000 m and 5000 m above the sea level The computations were carried out with Planetocosmics and CORSIKA codes as standardized Monte-Carlo tools for atmospheric cascade simulations. The flux of secondary neutrons and protons was computed using the Planetocosmics code appliyng a realistic curved atmospheric. Updated information concerning the NM registration efficiency for secondary neutrons and protons was used. The derived results for spectral and angular characteristics using the newly computed NM yield function at several altitudes are compared with the previously obtained ones using the double attenuation method.

  15. Application of magnetomechanical hysteresis modeling to magnetic techniques for monitoring neutron embrittlement and biaxial stress

    SciTech Connect

    Sablik, M.J.; Kwun, H.; Rollwitz, W.L.; Cadena, D.

    1992-01-01

    The objective is to investigate experimentally and theoretically the effects of neutron embrittlement and biaxial stress on magnetic properties in steels, using various magnetic measurement techniques. Interaction between experiment and modeling should suggest efficient magnetic measurement procedures for determining neutron embrittlement biaxial stress. This should ultimately assist in safety monitoring of nuclear power plants and of gas and oil pipelines. In the first six months of this first year study, magnetic measurements were made on steel surveillance specimens from the Indian Point 2 and D.C. Cook 2 reactors. The specimens previously had been characterized by Charpy tests after specified neutron fluences. Measurements now included: (1) hysteresis loop measurement of coercive force, permeability and remanence, (2) Barkhausen noise amplitude; and (3) higher order nonlinear harmonic analysis of a 1 Hz magnetic excitation. Very good correlation of magnetic parameters with fluence and embrittlement was found for specimens from the Indian Point 2 reactor. The D.C. Cook 2 specimens, however showed poor correlation. Possible contributing factors to this are: (1) metallurgical differences between D.C. Cook 2 and Indian Point 2 specimens; (2) statistical variations in embrittlement parameters for individual samples away from the stated men values; and (3) conversion of the D.C. Cook 2 reactor to a low leakage core configuration in the middle of the period of surveillance. Modeling using a magnetomechanical hysteresis model has begun. The modeling will first focus on why Barkhausen noise and nonlinear harmonic amplitudes appear to be better indicators of embrittlement than the hysteresis loop parameters.

  16. Monitoring Exposure to Ebola and Health of U.S. Military Personnel Deployed in Support of Ebola Control Efforts - Liberia, October 25, 2014-February 27, 2015.

    PubMed

    Cardile, Anthony P; Murray, Clinton K; Littell, Christopher T; Shah, Neel J; Fandre, Matthew N; Drinkwater, Dennis C; Markelz, Brian P; Vento, Todd J

    2015-07-03

    In response to the unprecedented Ebola virus disease (Ebola) outbreak in West Africa, the U.S. government deployed approximately 2,500 military personnel to support the government of Liberia. Their primary missions were to construct Ebola treatment units (ETUs), train health care workers to staff ETUs, and provide laboratory testing capacity for Ebola. Service members were explicitly prohibited from engaging in activities that could result in close contact with an Ebola-infected patient or coming in contact with the remains of persons who had died from unknown causes. Military units performed twice-daily monitoring of temperature and review of exposures and symptoms ("unit monitoring") on all persons throughout deployment, exit screening at the time of departure from Liberia, and post-deployment monitoring for 21 days at segregated, controlled monitoring areas on U.S. military installations. A total of 32 persons developed a fever during deployment from October 25, 2014, through February 27, 2015; none had a known Ebola exposure or developed Ebola infection. Monitoring of all deployed service members revealed no Ebola exposures or infections. Given their activity restrictions and comprehensive monitoring while deployed to Liberia, U.S. military personnel constitute a unique population with a lower risk for Ebola exposure compared with those working in the country without such measures.

  17. Cosmic ray sidereal diurnal variation of galactic origin observed by neutron monitors

    NASA Technical Reports Server (NTRS)

    Ishida, Y.; Nagashima, K.; Mori, S.; Morishita, I.

    1985-01-01

    Cosmic ray sidereal diurnal variations observed by neutron monitors are analyzed for the period 1961 to 1978, by adding 134 station years data to the previous paper (Nagashima, et al., 1983). Also the dependence of the sidereal variations on Sun's polar magnetic field polarity is examined for two periods; the period of negative polarity in the northern region, 1961 to 1969 and the period of positive polarity, 1970 to 1978. It is obtained that for the former period, the amplitude A=0.0203 + or 0.0020% and the phase phi=6.1 + or - 0.4 h LST and for the latter period, 0.0020% and phi=8.6 + or - 4 h LST, respectively.

  18. Cosmic Ray Modulation Observed by the Princess Sirindhorn Neutron Monitor at High Rigidity Cutoff

    NASA Astrophysics Data System (ADS)

    Mangeard, Pierre-Simon; Pyle, Roger; Evenson, Paul; Ruffolo, David; Saiz, Alejandro; Clem, John; Madlee, Suttiwat; Nutaro, Tanin

    2016-07-01

    Neutron monitors (NMs) are the premier instruments for precisely tracking time variations in the Galactic cosmic ray (GCR) flux at the GV-range. For more than 60 years, the worldwide NM network has provided continuous measurements of the solar induced variations of the GCR flux impinging Earth and the data cover about six 11-year solar cycles. The recent rise of space exploration, with PAMELA and AMS-02 spacecraft, brings new energy sensitive measurements of GCR fluxes. Moreover since late 2007, the range of sensitivity of the worldwide NM network has been increased with the installation of the Princess Sirindhorn Neutron Monitor (PSNM), at the summit of Doi Inthanon, Thailand's highest mountain (2565 m altitude). PSNM records the GCR flux with the world's highest vertical rigidity cutoff for a fixed station, 16.8 GV. PSNM data now cover the period from the last solar minimum to the recent solar maximum and give us the opportunity to study the effect of the solar modulation at such high rigidity for the first time. We present here the observations of PSNM since 2007. The observed solar modulation is much weaker than predicted by the force field model with φ inferred from NM data at low cutoff. We compare measurements with those from NMs located at low rigidity cutoff and with spacecraft data. We discuss the solar modulation at high rigidity. Partially supported by a postdoctoral fellowship from Mahidol University, the Thailand Research Fund (BRG 5880009), the Science Achievement Scholarship of Thailand, and US National Science Foundation awards PLR-1341562, PLR-1245939, and their predecessors.

  19. Investigation of the response of a neutron-Hand monitor dedicated to the powder diffractometer at CENM-Maamora

    SciTech Connect

    Messous, M.Y.; Belhorma, B.; Labrim, H.; Jabri, H.

    2015-07-01

    Neutrons are used for the study of condensed matter. A neutron beam can indeed easily penetrate the solid material and undergo diffraction phenomena. Analysis of the diffused neutrons allows studying the atomic structure of crossed material. Their neutral electric charge makes them nondestructive probe of a great interest. In general, the size of the powder samples is very small and therefore the centering of the beam on these is very crucial. It is in this context we proceed to test a portable neutron monitor for centering and checking beam leak around the shielding to be installed around the diffractometer in TRIGA Mark II of CENM. It's consisting of a scintillation neutron detector NE426 ({sup 6}LiF + ZnS (Ag)) with electronic module and data acquisition system. The effect of radiation from radioactive neutrons source {sup 252}Cf is shown. Sensitivity and differential linearity are also performed. This study indicates several advantages of this detector with very good detection sensitivity and excellent stability during the counting time. (authors)

  20. Tenth ORNL Personnel Dosimetry Intercomparison Study

    SciTech Connect

    Swaja, R.E.; Chou, T.L.; Sims, C.S.; Greene, R.T.

    1985-03-01

    The Tenth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory during April 9-11, 1984. Dosemeter badges from 31 participating organizations were mounted on 40cm Lucite phantoms and exposed to a range of dose equivalents which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the only source of radiation for eight of the ten irradiations which included a low (approx. 0.50 mSv) and high (approx. 10.00 mSv) neutron dose equivalent run for each of four shield conditions. Two irradiations were also conducted for which concrete- and Lucite-shield reactor irradiations were gamma-enhanced using a /sup 137/Cs source. Results indicated that some participants had difficulty obtaining measurable indication of neutron and gamma exposures at dose equivalents less than about 0.50 mSv and 0.20 mSv, respectively. Albedo dosemeters provided the best overall accuracy and precision for the neutron measurements. Direct interaction TLD systems showed significant variation in accuracy with incident spectrum, and threshold neutron dosemeters (film and recoil track) underestimated reference values by more than 50%. Gamma dose equivalents estimated in the mixed fields were higher than reference values with TL gamma dosemeters generally yielding more accurate results than film. Under the conditions of this study in which participants had information concerning exposure conditions and radiation field characteristics prior to dosemeter evaluation, only slightly more than half of all reported results met regulatory standards for neutron and gamma accuracy. 19 refs., 2 figs., 29 tabs.

  1. Performance of Current-Mode Ion Chambers as Beam Monitors in a Pulsed Cold Neutron Beam for the NPDGamma experiment

    NASA Astrophysics Data System (ADS)

    Gillis, R. Chad

    2006-10-01

    The NPDGamma collaboration has built and commissioned an apparatus to measure the parity-violating gamma asymmetry A in the low energy np capture process n+p->d+ γ. The asymmetry in question is a 10-8 correlation between the spin of the incident (polarized) neutron and the outgoing 2.2 MeV gamma ray. A set of purpose-built, 3He-filled ionization chambers read out in current mode is used to monitor the incident neutron flux, the beam polarization, and the transmission of the liquid para-hydrogen target during the NPDGamma measurements. As will be described in the talk, these beam monitors are simple, reliable, low-noise detectors that have performed excellently for NPDGamma. We have verified that the beam monitor signals can be interpreted to reproduce the known time-of-flight dependence of beam flux from the LANSCE pulsed cold neutron source, and that the neutron beam polarization can be measured at the 2% level from direct measurements of the transmission of the beam through the beam polarizer.

  2. Determination of neutron monitor barometric effect on the base of the altitude cosmic ray intensity dependence as measured by the Israelo-Italian mobile laboratory

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    In the way of transferring the Israelo-Italian moving laboratory with 6NM-64 neutron monitor from Italy to the place of stationary operation we did measurements of total neutron intensity, air pressure and intensities of neutron multiplicities m = 1, m = 2, m = 3, m = 4, m = 5, m = 6, m = 7 and m ≥ 8 in Haifa port (sea level, air pressure about 750 mmHg), in some intermediate points (about 626 mmHg), and in the final position of Emilio Segre' Observatory (33°18.3‧N, 35°47.2‧E, 2025 m above sea level, Rc = 10.8 GV ). By these data we determined first approximation cosmic ray barometric coefficients for total neutron component and for different neutron multiplicities (information on primary cosmic ray variations on the basis of Rome neutron monitor data have been taken into account).

  3. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    SciTech Connect

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  4. One hour neutron monitor and muon telescope on-line CR data and space dangerous phenomena

    NASA Astrophysics Data System (ADS)

    Zagnetko, Alexander; Applbaum, David; Dorman, Lev; Pustil'Nik, Lev; Sternlieb, Abraham; Zukerman, Igor

    We apply developing of methods in Zagnetko et al. (2010) for forecasting on the basis of neutron monitor hourly on-line data (as well as on-line muon telescopes hourly data from different directions) geomagnetic storms of scales G5 (3-hour index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) (according to NOAA Space Weather Scales). These geo-magnetic storms are dangerous for people technology and health (influence on power systems, on spacecraft operations, on HF radio-communications and others). We show that for espe-cially dangerous geomagnetic storms can be used global-spectrographic method if on-line will be available 35-40 NM and muon telescopes. In this case for each hour can be determined CR anisotropy vector, and the specifically behavior of this vector before SC of geomagnetic storms G5, G4 or G3 (according to NOAA Space Weather Scales) can be used as important factor for forecast. The second factor what can be used for SC forecast is specifically behavior of CR density (CR intensity) for about 30-15 hours before SC (caused mainly by galactic CR parti-cles acceleration during interaction with shock wave moved from the Sun). The third factor is effect of cosmic ray pre-decreasing, caused by magnetic connection of the Earth with the region behind the shock wave. We demonstrate developing methods on several examples of major geomagnetic storms. For each case we analyze hourly data of many NM for 8 days with SC in the 4-st day of 8-days period (so before SC we have at least 3 full days). We determine what part of major geomagnetic storms is accompanied CR intensity and CR anisotropy changing before SC, and what part of major geomagnetic storms does not show any features what can be used for forecasting. We estimate also how these parts depend from the index of geomagnetic activity Kp. REFERENCES: Zagnetko et al. "One hour neutron monitor and muon telescope on-line CR data and space dangerous phenomena, 1. Principles of major geomagnetic storms

  5. EXPERIENCE MONITORING FOR LOW LEVEL NEUTRON RADIATION AT THE H-CANYON AT THE SAVANNAH RIVER SITE

    SciTech Connect

    HOGUE, MARK

    2005-10-07

    Department of Energy contractors are required to monitor external occupational radiation exposure of an individual likely to receive an effective dose equivalent to the whole body of 0.1 rem (0.001sievert) or more in a year. For a working year of 2000 hours, this translates to a dose rate of 0.05 mrem/hr (0.5 {micro}Sv/hr). This can be a challenging requirement for neutron exposure because traditional surveys with shielded BF{sub 3} proportional counters are difficult to conduct, particularly at low dose rates. A modified survey method was used at the Savannah River Site to find low dose rates in excess of 0.05 mrem/hr. An unshielded He{sup 3} detector was used to find elevated gross slow neutron counts. Areas with high count rates on the unshielded He{sup 3} detector were further investigated with shielded BF{sub 3} proportional counters and thermoluminescent neutron dosimeters were placed in the area of interest. An office area was investigated with this method. The data initially suggested that whole body neutron dose rates to office workers could be occurring at levels significantly higher than 0.1 rem (0.001sievert). The final evaluation, however, showed that the office workers were exposed to less than 0.1 rem/yr (0.001sievert/yr) of neutron radiation.

  6. Progress in the development of the neutron flux monitoring system of the French GEN-IV SFR: simulations and experimental validations [ANIMMA--2015-IO-98

    SciTech Connect

    Jammes, C.; Filliatre, P.; De Izarra, G.; Elter, Zs.; Pazsit, I.; Verma, V.; Hellesen, C.; Jacobsson, S.; Hamrita, H.; Bakkali, M.; Chapoutier, N.; Scholer, A-C.; Verrier, D.; Cantonnet, B.; Nappe, J-C.; Molinie, P.; Dessante, P.; Hanna, R.; Kirkpatrick, M.; Odic, E.; Jadot, F.

    2015-07-01

    The neutron flux monitoring system of the French GEN-IV sodium-cooled fast reactor will rely on high temperature fission chambers installed in the reactor vessel and capable of operating over a wide-range neutron flux. The definition of such a system is presented and the technological solutions are justified with the use of simulation and experimental results. (authors)

  7. Calculating Hurst exponent and neutron monitor data in a single parallel algorithm

    NASA Astrophysics Data System (ADS)

    Kussainov, A. S.; Kussainov, S. G.

    2015-09-01

    We implemented an algorithm for simultaneous parallel calculation of the Hurst exponent H and the fractal dimension D for the time series of interest. Parallel programming environment was provided by OpenMPI library installed on three machines networked in the virtual cluster and operated by Debian Wheeze operating system. We applied our program for a comparative analysis of week and a half long, one minute resolution, six channels data from neutron monitor. To ensure a faultless functioning of the written code we applied it to analysis of the random Gaussian noise signal and time series with manually introduced self-affinity features. Both of them have the well-known values of H and D. All results are in good correspondence with each other and supported by the modern theories on signal processing thus confirming the validity of the implemented algorithms. Our code could be used as a standalone tool for the different time series data analysis as well as for the further work on development and optimization of the parallel algorithms for the time series parameters calculations.

  8. Investigation on contribution of neutron monitor data to estimation of aviation doses

    NASA Astrophysics Data System (ADS)

    Kákona, M.; Ploc, O.; Kyselová, D.; Kubančák, J.; Langer, R.; Kudela, K.

    2016-11-01

    Recently, many efforts have appeared to routinely measure radiation exposure (RE) of aircraft crew due to cosmic rays (CR). On the other hand real-time CR data measured with the ground based neutron monitors (NMs) are collected worldwide and available online. This is an opportunity for comparison of long-term observations of RE at altitudes of about 10 km, where composition and energy spectra of secondary particles differ from those on the ground, with the data from NMs. Our contribution presents examples of such type of comparison. Analysis of the silicon spectrometer Liulin measurements aboard aircraft is presented over the period May-September 2005 and compared with data from a single NM at middle latitude. While extreme solar driven events observed by NMs have clearly shown an impact on dosimetric characteristics as measured on the airplanes, the transient short time effects in CR of smaller amplitude have been not studied extensively in relation to RE. For the period May-September 2005, when aircraft data become available and several Forbush decreases (FDs) are observed on the ground, a small improvement in the correlation between the dose measured and multiple linear regression fit based on two key parameters (altitude and geomagnetic cut-off rigidity), is obtained, if the CR intensity at a single NM is added into the scheme.

  9. Altitude survey of the galactic cosmic ray flux with a Mini Neutron Monitor

    NASA Astrophysics Data System (ADS)

    Lara, A.; Borgazzi, A.; Caballero-Lopez, R.

    2016-10-01

    We present the results of a survey of the galactic cosmic ray (GCR) flux measured at different altitudes, from the sea level, up to ∼4600 m a.s.l. This altitude survey was carried out with a "Mini" Neutron Monitor (MNM), and performed inside a small area of the central part of Mexico (centered around the 19° N and 97° W position) where the geomagnetic cutoff rigidity is ∼7.8 GV. In particular, the latitudinal variation of the survey was less than 1°. making negligible the associated changes in the geomagnetic cutoff rigidity (∼0.4 GV). This is the first time that an altitude survey has been performed using a MNM. This survey allowed us to compute the barometric coefficient β = 0.00732 ± 0.00054mbar-1 and β = 0.00729 ± 0.00055mbar-1 when we correct our data by the differences in the cutoff rigidity. This coefficient may be used to calibrate and correct the data of other cosmic ray detectors. We show that from the sea level up to ∼4600 m the barometric coefficient is constant and does not depend on the altitude as found in previous surveys. For comparison, we also present the counting rates measured by the NM64 located at Mexico City, as well as other observations carried out to determine the stability of the MNM.

  10. SU-E-T-108: Development of a Novel Clinical Neutron Dose Monitor for Proton Therapy Based On Twin TLD500 Chips in a Small PE Moderator

    SciTech Connect

    Hentschel, R; Mukherjee, B

    2014-06-01

    Purpose: In proton therapy, it could be desirable to measure out-of-field fast neutron doses at critical locations near and outside the patient body. Methods: The working principle of a novel clinical neutron dose monitor is verified by MCNPX simulation. The device is based on a small PE moderator of just 5.5cm side length for easy handling covered with a thermal neutron suppression layer. In the simulation, a polystyrene phantom is bombarded with a standard proton beam. The secondary thermal neutron flux produced inside the moderator by the impinging fast neutrons from the treatment volume is estimated by pairs of α-Al2O3:C (TLD500) chips which are evaluated offline after the treatment either by TL or OSL methods. The first chip is wrapped with 0.5mm natural Gadolinium foil converting the thermal neutrons to gammas via (n,γ) reaction. The second chip is wrapped with a dummy material. The chip centers have a distance of 2cm from each other. Results: The simulation shows that the difference of gamma doses in the TLD500 chips is correlated to the mean fast neutron dose delivered to the moderator material. Different outer shielding materials have been studied. 0.5mm Cadmium shielding is preferred for cost reasons and convenience. Replacement of PE moderator material by other materials like lead or iron at any place is unfavorable. The spatial orientation of the moderator cube is uncritical. Using variance reduction techniques like splitting/Russian roulette, the TLD500 gamma dose simulation give positive differences up to distances of 0.5m from the treatment volume. Conclusion: Applicability and basic layout of a novel clinical neutron dose monitor are demonstrated. The monitor measures PE neutron doses at locations outside the patient body up to distances of 0.5m from the treatment volume. Tissue neutron doses may be calculated using neutron kerma factors.

  11. Emilio Segre' Observatory and expected time-variations in neutron monitor total and multiplicities counting rates caused by cosmic ray particle energy change in the periods of thunderstorms

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    In the first part of paper we give short description of the Israelo-Italian Emilio Segre' Observatory (33°18.3‧N, 35°47.2‧E, 2025 m above sea level, Rc=10.8 GV), established in June 1998. In the second part, on the basis of theoretical model (Dorman & Dorman 1995, 1999; Dorman et al. 1995) of atmospheric electric field effect in the neutron monitor total counting rate and counting rates of different neutron multiplicities, we calculate the expected cosmic ray time variations in the different channels of 6NM-64 neutron monitor of Emilio Segre' Observatory in the periods before and during thunderstorms. Our calculations show that one-minute data of 6NM-64 neutron monitor of Emilio Segre' Observatory and one minute data of EFS-1000 sensor of atmospheric electric field can be used for obtaining important information on atmospheric electric field space-time distribution.

  12. Observation of Periodic and Transient Cosmic Ray Flux Variations by the Daejeon Neutron Monitor and the Seoul muon Detector

    NASA Astrophysics Data System (ADS)

    Oh, Suyeon; Kang, Jeongsoo

    2013-09-01

    Recently, two instruments of cosmic ray are operating in South Korea. One is Seoul muon detector after October 1999 and the other is Daejeon neutron monitor (Kang et al. 2012) after October 2011. The former consists of four small plastic scintillators and the latter is the standard 18 NM 64 type. In this report, we introduce the characteristics of both instruments. We also analyze the flux variations of cosmic ray such as diurnal variation and Forbush decrease. As the result, the muon flux shows the typical seasonal and diurnal variations. The neutron flux also shows the diurnal variation. The phase which shows the maximum flux in the diurnal variation is around 13-14 local time. We found a Forbush decrease on 7 March 2012 by both instruments. It is also identified by Nagoya multi-direction muon telescope and Oulu neutron monitor. The observation of cosmic ray at Jangbogo station as well as in Korean peninsula can support the important information on space weather in local area. It can also enhance the status of Korea in the international community of cosmic ray experiments.

  13. Pulsed-Neutron-Gamma (PNG) saturation monitoring at the Ketzin pilot site considering displacement and evaporation/precipitation processes

    NASA Astrophysics Data System (ADS)

    Baumann, Gunther; Henninges, Jan

    2013-04-01

    The storage of carbon dioxide (CO2) in saline aquifers is a promising option to reduce emissions of greenhouse gases to the atmosphere and to mitigate global climate change. During the proposed CO2 injection process, application of suitable techniques for monitoring of the induced changes in the subsurface is required. Existing models for the spreading of the CO2, as well as mixing of the different fluids associated with saturation changes or resulting issues from mutual solubility between brine and CO2, need to be checked. For well logging in cased boreholes, which would be the standard situation encountered under the given conditions, only a limited number of techniques like pulsed neutron-gamma (PNG) logging are applicable. The PNG technique uses controlled neutron bursts, which interact with the nuclei of the surrounding borehole and formation. Due to the collision with these neutrons, atoms from the surrounding environment emit gamma rays. The main PNG derived parameter is the capture cross section (Σ) which is derived from the decline of gamma rays with time from neutron capture processes. The high Σ contrast between brine and CO2 results in a high sensitivity to evaluate saturation changes. This makes PNG monitoring favourable for saturation profiling especially in time-lapse mode. Previously, the conventional PNG saturation model based on a displacement process has been used for PNG interpretation in different CO2 storage projects in saline aquifers. But in addition to the displacement process, the mutual solubility between brine and CO2 adds further complex processes like evaporation and salt precipitation, which are not considered in PNG saturation models. These evaporation and precipitation processes are relevant in the vicinity of an injection well, where dry CO2 enters the reservoir. The Σ brine value depends strongly on the brine salinity e.g. its chlorine content which makes PNG measurements suitable for evaporation and salt precipitation

  14. Integration of cosmic-ray neutron probes into production agriculture: Lessons from the Platte River cosmic-ray neutron probe monitoring network

    NASA Astrophysics Data System (ADS)

    Avery, W. A.; Finkenbiner, C. E.; Franz, T. E.; Nguy-Robertson, A. L.; Munoz-Arriola, F.; Suyker, A.; Arkebauer, T. J.

    2015-12-01

    Projected increases in global population will put enormous pressure on fresh water resources in the coming decades. Approximately 70 percent of human water use is allocated to agriculture with 40 percent of global food production originating from irrigated lands. Growing demand for food will only worsen the strain placed on many irrigated agricultural systems resulting in an unsustainable reliance on groundwater. This work presents an overview of the Platte River Cosmic-ray Neutron Probe Monitoring Network, which consists of 10 fixed probes and 3 mobile probes located across the Platte River Basin. The network was installed in 2014 and is part of the larger US COSMOS (70+ probes) and global COSMOS networks (200+ probes). Here we will present an overview of the network, comparison of fixed neutron probe results across the basin, spatial mapping results of the mobile sensors at various sites and spatial scales, and lessons learned by working with various producers and water stakeholder groups. With the continued development of this technique, its incorporation for soil moisture management in large producer operations has the potential to increase irrigation water use efficiency in the Platte River Basin and beyond.

  15. ESTIMATION OF NEUTRON SCATTER CORRECTION FOR CALIBRATION OF PERSONNEL DOSIMETER AND DOSERATEMETER AGAINST 241Am-Be SOURCE-MONTE CARLO SIMULATION AND MEASUREMENTS.

    PubMed

    Dawn, Sandipan; Bakshi, A K; Sathian, Deepa; Selvam, T Palani

    2016-10-07

    Neutron scatter contributions as a function of distance along the transverse axis of (241)Am-Be source were estimated by three different methods such as shadow cone, semi-empirical and Monte Carlo. The Monte Carlo-based FLUKA code was used to simulate the existing room used for the calibration of CR-39 detector as well as LB6411 doseratemeter for selected distances from (241)Am-Be source. The modified (241)Am-Be spectra at different irradiation geometries such as at different source detector distances, behind the shadow cone, at the surface of the water phantom were also evaluated using Monte Carlo calculations. Neutron scatter contributions, estimated using three different methods compare reasonably well. It is proposed to use the scattering correction factors estimated through Monte Carlo simulation and other methods for the calibration of CR-39 detector and doseratemeter at 0.75 and 1 m distance from the source.

  16. Procedure to emend neutron monitor data that are affected by snow accumulations on and around the detector housing

    NASA Astrophysics Data System (ADS)

    Korotkov, V.; Berkova, M.; Belov, A.; Eroshenko, E.; Yanke, V.; Pyle, R.

    2013-11-01

    In this work, a method of neutron monitor data correction for the snow effect caused by the snow accumulation on and around the detector housing is described. This is particularly important for some high-latitude and mountain cosmic ray stations. The results of manual correction are compared with the results of automatic correction on the basis of the algorithm developed here. The proposed method has been applied to a number of cosmic ray stations where the snow accumulation is large and variable during the winter, for example, Magadan, Emilio Segre Observatory in Israel, Moscow Cosmic Ray Laboratory, Jungfraujoch, and Nain.

  17. Neutron monitoring and electrode calorimetry experiments in the HIP-1 Hot Ion Plasma

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Layman, R. W.

    1977-01-01

    Results are presented for two diagnostic procedures on HIP-1: neutron diagnostics to determine where neutrons originated within the plasma discharge chamber and electrode calorimetry to measure the steady-state power absorbed by the two anodes and cathodes. Results are also reported for a hot-ion plasma formed with a continuous-cathode rod, one that spans the full length of the test section, in place of the two hollow cathodes. The outboard neutron source strength increased relative to that at the midplane when (1) the cathode tips were moved farther outboard, (2) the anode diameters were increased, and (3) one of the anodes was removed. The distribution of neutron sources within the plasma discharge chamber was insensitive to the division of current between the two cathodes. For the continuous cathode, increasing the discharge current increased the midplane neutron source strength relative to the outboard source strength. Each cathode absorbed from 12 to 15 percent of the input power regardless of the division of current between the cathodes. The anodes absorbed from 20 to 40 percent of the input power. The division of power absorption between the anodes varied with plasma operating conditions and electrode placement.

  18. Novel methods for aircraft corrosion monitoring

    NASA Astrophysics Data System (ADS)

    Bossi, Richard H.; Criswell, Thomas L.; Ikegami, Roy; Nelson, James; Normand, Eugene; Rutherford, Paul S.; Shrader, John E.

    1995-07-01

    Monitoring aging aircraft for hidden corrosion is a significant problem for both military and civilian aircraft. Under a Wright Laboratory sponsored program, Boeing Defense & Space Group is investigating three novel methods for detecting and monitoring hidden corrosion: (1) atmospheric neutron radiography, (2) 14 MeV neutron activation analysis and (3) fiber optic corrosion sensors. Atmospheric neutron radiography utilizes the presence of neutrons in the upper atmosphere as a source for interrogation of the aircraft structure. Passive track-etch neutron detectors, which have been previously placed on the aircraft, are evaluated during maintenance checks to assess the presence of corrosion. Neutrons generated by an accelerator are used via activation analysis to assess the presence of distinctive elements in corrosion products, particularly oxygen. By using fast (14 MeV) neutrons for the activation, portable, high intensity sources can be employed for field testing of aircraft. The third novel method uses fiber optics as part of a smart structure technology for corrosion detection and monitoring. Fiber optic corrosion sensors are placed in the aircraft at locations known to be susceptible to corrosion. Periodic monitoring of the sensors is used to alert maintenance personnel to the presence and degree of corrosion at specific locations on the aircraft. During the atmospheric neutron experimentation, we identified a fourth method referred to as secondary emission radiography (SER). This paper discusses the development of these methods.

  19. Development of a technique for improving coefficient of variation of CaSO4:Dy teflon-based TLD personnel monitoring system in low-dose region.

    PubMed

    Pradhan, S M; Sneha, C; Sahai, M K; Chougaonkar, M P; Babu, D A R

    2015-12-01

    In view of the importance of zero-dose background (null signal) in influencing the coefficient of variation in low-dose region, a technique for the estimation of the same from composite (gross) signal is developed for CaSO4:Dy-based personnel monitoring system being used in India. The technique is based on simple analysis of glow curves (GCs) of unexposed and exposed dosemeters, evolution of trend/model for the zero-dose curves, generation of simulation protocol for individual zero-dose curves, establishment of characteristics of GCs of exposed dosemeters and finally preparation of an algorithm to segregate the components from composite signal. The technique offers the separation of real-time background and gives superior results over other method of approximation of the background. The results also prove efficiency of the empirical trending and simulation protocol of background GCs. The proposed technique can be implemented in routine monitoring without any extra man hours and reader time.

  20. Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

    DOEpatents

    Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

    2012-08-07

    A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

  1. Monitoring a liquid waste stream with a delayed-neutron instrument

    SciTech Connect

    Rinard, P.M.; Van Lyssel, T.; Kroncke, K.E.; Schneider, C.M.; Bourret, S.C.

    1989-01-01

    A flowing raffinate stream is to be continuously assayed by a delayed-neutron instrument to detect concentrations of {sup 235}U that could cause a criticality problem in a holding tank. The instrument is to assay a concentration of 0.034 (g {sup 235}U)/L in 100 s with a precision of 10% (1 {sigma}) and to operate unattended for a few months at a time, so it can detect and adjust for changes in the neutron background, the flow rate, and for electronic drifts and malfunctions. In laboratory tests with conditions slightly different from what may be found in the plant, repeated assays on a solution with 0.034 (g {sup 235}U)/L flowing at 80 L/h through the 2-L assay tank had relative precisions of 9-11%. 5 refs., 5 figs.

  2. Use of cosmic-ray neutron sensors for soil moisture monitoring in forests

    NASA Astrophysics Data System (ADS)

    Heidbüchel, Ingo; Güntner, Andreas; Blume, Theresa

    2016-03-01

    Measuring soil moisture with cosmic-ray neutrons is a promising technique for intermediate spatial scales. To convert neutron counts to average volumetric soil water content a simple calibration function can be used (the N0-calibration of Desilets et al., 2010). The calibration is based on soil water content derived directly from soil samples taken within the footprint of the sensor. We installed a cosmic-ray neutron sensor (CRS) in a mixed forest in the lowlands of north-eastern Germany and calibrated it 10 times throughout one calendar year. Each calibration with the N0-calibration function resulted in a different CRS soil moisture time series, with deviations of up to 0.1 m3 m-3 (24 % of the total range) for individual values of soil water content. Also, many of the calibration efforts resulted in time series that could not be matched with independent in situ measurements of soil water content. We therefore suggest a modified calibration function with a different shape that can vary from one location to another. A two-point calibration was found to effectively define the shape of the modified calibration function if the calibration points were taken during both dry and wet conditions spanning at least half of the total range of soil moisture. The best results were obtained when the soil samples used for calibration were linearly weighted as a function of depth in the soil profile and nonlinearly weighted as a function of distance from the CRS, and when the depth-specific amount of soil organic matter and lattice water content was explicitly considered. The annual cycle of tree foliation was found to be a negligible factor for calibration because the variable hydrogen mass in the leaves was small compared to the hydrogen mass changes by soil moisture variations. As a final point, we provide a calibration guide for a CRS in forested environments.

  3. Use of cosmic ray neutron sensors for soil moisture monitoring in forests

    NASA Astrophysics Data System (ADS)

    Heidbüchel, Ingo; Güntner, Andreas; Blume, Theresa

    2016-04-01

    Measuring soil moisture with cosmic ray neutrons is a promising technique for intermediate spatial scales. To convert neutron counts to average volumetric soil water content a simple calibration function can be used (the N0-calibration of Desilets et al., 2010). The calibration is based on soil water content derived directly from soil samples taken within the footprint of the sensor. We installed a cosmic-ray neutron sensor (CRS) in a mixed forest in the lowlands of north-eastern Germany and calibrated it 10 times throughout one calendar year. Each calibration with the N0-calibration function resulted in a different CRS soil moisture time series, with deviations of up to 0.12 m3 m-3 for individual values of soil water content. Also, many of the calibration efforts resulted in time series that could not be matched with independent in situ measurements of soil water content. We therefore suggest a modified calibration function with a different shape that can vary from one location to another. A two-point calibration proved to be adequate to correctly define the shape of the modified calibration function if the calibration points were taken during both dry and wet conditions spanning at least half of the total range of soil moisture. The best results were obtained when the soil samples used for calibration were linearly weighted as a function of depth in the soil profile and non-linearly weighted as a function of distance from the CRS, and when the depth-specific amount of soil organic matter and lattice water content was explicitly considered. The annual cycle of tree foliation was found to be a negligible factor for calibration because the variable hydrogen mass in the leaves was small compared to the hydrogen mass changes by soil moisture variations. We will also provide a best practice calibration guide for CRS in forested environments.

  4. Neutron measurements

    SciTech Connect

    McCall, R.C.

    1981-01-01

    Methods of neutron detection and measurement are discussed. Topics include sources of neutrons, neutrons in medicine, interactions of neutrons with matter, neutron shielding, neutron measurement units, measurement methods, and neutron spectroscopy. (ACR)

  5. Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22.

    PubMed

    Silva, H G; Lopes, I

    Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

  6. Dynamics of two-year cosmic ray variations inferred from the data of spacecraft and stratospheric measurements and from the neutron monitor data in 1959-1981

    NASA Technical Reports Server (NTRS)

    Charakhchyan, T. N.; Gorchakov, E. V.; Okhlopkov, V. P.; Okhlopkova, L. S.; Ternovskaya, M. V.

    1985-01-01

    The two year cosmic ray variations are studied using the spacecraft measurements of 1967 to 1976, the sonde measurements at high latitudes in the stratosphere (Murmansk, Mirny), and the neutron monitor data of 1959 to 1981. The two year variations are most pronounced from 1967 to 1975. An anticorrelation is observed between the two year variations in cosmic rays and in geomagnetic activity.

  7. Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22

    NASA Astrophysics Data System (ADS)

    Silva, H. G.; Lopes, I.

    2016-07-01

    Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

  8. Diverse methods of analyzing neutron detector signal for power monitoring in commercial fast reactors

    SciTech Connect

    Sivaramakrishna, M.; Nagaraj, C. P.; Madhusoodanan, K.

    2011-07-01

    In a fast reactor, the measurement of instantaneous power, accurately at any point of time is of prime importance. To control the reactor power within its design limit for safe operation, measurement of power and safety functions operated by different systems based on power is required. This is done with neutron detectors from which signal come as current pulses in random following Poisson distribution. Due to heavy overlap, individual pulse counting is extremely difficult beyond certain frequency. So to count pulses in the detector output in a given length of time, which will be measure of power in the reactor, indirect method of signal processing is applied here. After applying signal processing methods on the detector output, linear relation is established between maximum amplitude of absolute of FFT (Fast Fourier Transform) of the signal and no of pulses in a given length of time of the signal i.e. rate of arrival of pulses to the detector. This linear relation is verified in different ways i.e. with simulated fixed rate of arrival of the pulses, random rate of arrival of the pulses and with neutron detector simulator output. The paper explains various stages of development and testing. (authors)

  9. High Sensitive Neutron-Detection by Using a Self-Activation of Iodine-Containing Scintillators for the Photo-Neutron Monitoring around X-ray Radiotherapy Machines

    NASA Astrophysics Data System (ADS)

    Nohtomi, Akihiro; Wakabayashi, Genichiro; Kinoshita, Hiroyuki; Honda, Soichiro; Kurihara, Ryosuke; Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko; Ohga, Saiji; Nakamura, Katsumasa

    A novel method for evaluating the neutron dose-equivalent as well as neutron fluence around high-energy X-ray radiotherapy machines has been proposed and examined by using the self-activation of a CsI scintillator. Several filtering conditions were used to extract energy information of the neutron field. The shapes of neutron energy spectra were assumed to be practically unchanged at each three energy regions (thermal, epi-thermal and fast regions) for different irradiations around an X-ray linac whose acceleration potential was fixed to be a certain value. In order to know the actual neutron energy spectrum, an unfolding process was carried out for saturated activities of 128I generated inside the CsI scintillator under different filtering conditions; the response function matrix for each filtering condition was calculated by a Monte Carlo simulation. As the result, neutron dose-equivalent was estimated to be 0.14 (mSv/Gy) at 30 cm from the isocenter of linac. It has been revealed that fast neutron component dominated the total dose-equivalent.

  10. Low-level gamma and neutron monitoring based on use of proportional counter filled with 3He in polythene moderator: study of the responses to gamma and neutrons.

    PubMed

    Pszona, S; Bantsar, A; Tulik, P; Wincel, K; Zaręba, B

    2014-10-01

    It has been shown that a proportional counter filled with (3)He placed centrally inside a polythene sphere opens a new possibility for measuring gamma photons and neutrons in the separate pulse-height windows. The responses to gamma and neutrons (in terms of ambient dose equivalent) of the detector assembly consisting of 203-mm polythene sphere with centrally positioned 40-mm diameter (3)He proportional counter have been studied. The response to secondary gammas from capture process in hydrogen has also been studied. The rather preliminary studies indicate that the proposed measuring system has very promising features as an ambient dose equivalent device for mixed gamma-neutron fields.

  11. Radial fast-neutron fluence gradients during rotating 40Ar/39Ar sample irradiation recorded with metallic fluence monitors and geological age standards

    NASA Astrophysics Data System (ADS)

    Rutte, Daniel; Pfänder, Jörg A.; Koleška, Michal; Jonckheere, Raymond; Unterricker, Sepp

    2015-01-01

    the neutron-irradiation parameter J is one of the major uncertainties in 40Ar/39Ar dating. The associated uncertainty of the individual J-value for a sample of unknown age depends on the accuracy of the age of the geological standards, the fast-neutron fluence distribution in the reactor, and the distances between standards and samples during irradiation. While it is generally assumed that rotating irradiation evens out radial neutron fluence gradients, we observed axial and radial variations of the J-values in sample irradiations in the rotating channels of two reactors. To quantify them, we included three-dimensionally distributed metallic fast (Ni) and thermal- (Co) neutron fluence monitors in three irradiations and geological age standards in three more. Two irradiations were carried out under Cd shielding in the FRG1 reactor in Geesthacht, Germany, and four without Cd shielding in the LVR-15 reactor in Řež, Czech Republic. The 58Ni(nf,p)58Co activation reaction and γ-spectrometry of the 811 keV peak associated with the subsequent decay of 58Co to 58Fe allow one to calculate the fast-neutron fluence. The fast-neutron fluences at known positions in the irradiation container correlate with the J-values determined by mass-spectrometric 40Ar/39Ar measurements of the geological age standards. Radial neutron fluence gradients are up to 1.8 %/cm in FRG1 and up to 2.2 %/cm in LVR-15; the corresponding axial gradients are up to 5.9 and 2.1 %/cm. We conclude that sample rotation might not always suffice to meet the needs of high-precision dating and gradient monitoring can be crucial.

  12. Toward prompt gamma spectrometry for monitoring boron distributions during extra corporal treatment of liver metastases by boron neutron capture therapy: a Monte Carlo simulation study.

    PubMed

    Khelifi, R; Nievaart, V A; Bode, P; Moss, R L; Krijger, G C

    2009-07-01

    A Monte Carlo calculation was carried out for boron neutron capture therapy (BNCT) of extra corporal liver phantom. The present paper describes the basis for a subsequent clinical application of the prompt gamma spectroscopy set-up aimed at in vivo monitoring of boron distribution. MCNP code was used first to validate the homogeneity in thermal neutron field in the liver phantom and simulate the gamma ray detection system (collimator and detector) in the treatment room. The gamma ray of 478 keV emitted by boron in small specific region can be detected and a mathematical formalism was used for the tomography image reconstruction.

  13. A method for the monitoring of metal recrystallization based on the in-situ measurement of the elastic energy release using neutron diffraction

    SciTech Connect

    Christien, F. Le Gall, R.; Telling, M. T. F.; Knight, K. S.

    2015-05-15

    A method is proposed for the monitoring of metal recrystallization using neutron diffraction that is based on the measurement of stored energy. Experiments were performed using deformed metal specimens heated in-situ while mounted at the sample position of the High Resolution Powder Diffractometer, HRPD (ISIS Facility), UK. Monitoring the breadth of the resulting Bragg lines during heating not only allows the time-dependence (or temperature-dependence) of the stored energy to be determined but also the recrystallized fraction. The analysis method presented here was developed using pure nickel (Ni270) specimens with different deformation levels from 0.29 to 0.94. In situ temperature ramping as well as isothermal annealing was undertaken. The method developed in this work allows accurate and quantitative monitoring of the recrystallization process. The results from neutron diffraction are satisfactorily compared to data obtained from calorimetry and hardness measurements.

  14. A method for the monitoring of metal recrystallization based on the in-situ measurement of the elastic energy release using neutron diffraction

    NASA Astrophysics Data System (ADS)

    Christien, F.; Telling, M. T. F.; Knight, K. S.; Le Gall, R.

    2015-05-01

    A method is proposed for the monitoring of metal recrystallization using neutron diffraction that is based on the measurement of stored energy. Experiments were performed using deformed metal specimens heated in-situ while mounted at the sample position of the High Resolution Powder Diffractometer, HRPD (ISIS Facility), UK. Monitoring the breadth of the resulting Bragg lines during heating not only allows the time-dependence (or temperature-dependence) of the stored energy to be determined but also the recrystallized fraction. The analysis method presented here was developed using pure nickel (Ni270) specimens with different deformation levels from 0.29 to 0.94. In situ temperature ramping as well as isothermal annealing was undertaken. The method developed in this work allows accurate and quantitative monitoring of the recrystallization process. The results from neutron diffraction are satisfactorily compared to data obtained from calorimetry and hardness measurements.

  15. A method for the monitoring of metal recrystallization based on the in-situ measurement of the elastic energy release using neutron diffraction.

    PubMed

    Christien, F; Telling, M T F; Knight, K S; Le Gall, R

    2015-05-01

    A method is proposed for the monitoring of metal recrystallization using neutron diffraction that is based on the measurement of stored energy. Experiments were performed using deformed metal specimens heated in-situ while mounted at the sample position of the High Resolution Powder Diffractometer, HRPD (ISIS Facility), UK. Monitoring the breadth of the resulting Bragg lines during heating not only allows the time-dependence (or temperature-dependence) of the stored energy to be determined but also the recrystallized fraction. The analysis method presented here was developed using pure nickel (Ni270) specimens with different deformation levels from 0.29 to 0.94. In situ temperature ramping as well as isothermal annealing was undertaken. The method developed in this work allows accurate and quantitative monitoring of the recrystallization process. The results from neutron diffraction are satisfactorily compared to data obtained from calorimetry and hardness measurements.

  16. PERSONNEL DOSIMETER

    DOEpatents

    Birkhoff, R.D.; Hubbell, H.H. Jr.; Johnson, R.M.

    1959-02-24

    A personnel dosimeter sensitive to both gamma and beta radiation is described. The dosimeter consists of an electrical conductive cylinder having a wall thickness of substantially 7 milligrams per square centimeter and an electrode disposed axially within the cylinder and insulated therefrom to maintain a potential impressed between the electrode and the cylinder. A cylindrical perforated shield provided with a known percentage of void area is disposed concentrically about the cylinder. The shield is formed of a material which does not contain more than 15 percent of an element higher than atomic weight 13. The dose actually received is at most the gamma dose plus the beta dose indicated by discharge of the dosimeter divided by the known percentage.

  17. Numerical analysis of a neutron radiography-monitored infiltration experiment: Two-phase modeling using TOUGH2

    NASA Astrophysics Data System (ADS)

    Princ, Tomas; Sacha, Jan; Snehota, Michal

    2015-04-01

    It has been shown in ponded infiltration-outflow column experiments that true steady state flow is often not reached in certain soils exhibiting preferential flow. Experiments often show a temporal change of flow rate that can, in the case of experiments conducted on saturated samples at constant head gradients, be interpreted as variations of saturated hydraulic conductivity. It has also been shown that these variations can be caused by slow redistribution of entrapped air in the sample. The experiment presented in this study was conducted on a small fabricated sample with axially symmetrical inner geometry of material distribution. In preparing the sample, areas of fine sand were surrounded by continuous preferential pathways composed of coarse sand. Ponded infiltration was performed on the sample while monitoring using neutron imaging was conducted to obtain spatiotemporal information about the water content distribution in the sample. Results of the experiment revealed that during the quasi-steady state stage of the experiment the saturated hydraulic conductivity gradually decreased due to the transfer of air bubbles from fine sand to coarse sand. Flow through the coarse sand became partially blocked by air bubbles and the overall quasi-steady flow rate consequently decreased by 30% during six hours of infiltration. In an attempt to model this behavior, we simulated ponded infiltration in two dimensional (2D) domains using the EOS3 module of the numerical simulator TOUGH2 (Lawrence Berkeley National Laboratory). The main objective was to determine which types of preferential pathway patterns were prone to air entrapment and whether the air redistribution observed in the experiment could be numerically simulated. Modeling was conducted in three different 2D domains with increasing complexity of the preferential pathways' geometry. Analysis of the results confirmed that during ponded infiltration, water percolated fastest at the start of infiltration through the

  18. Compact telemetry package for remote monitoring of neutron responses in animals

    NASA Technical Reports Server (NTRS)

    Baker, C. D.

    1974-01-01

    Battery-powered telemeter includes FM transmitter and is light enough to be mounted on animal's head. Animal has complete freedom of movement while its neuron responses are transmitted to receiver in laboratory. Construction may also be applied to monitor blood pressure, body temperature, and different muscular signals.

  19. Measurement result of the neutron monitor onboard the Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP)

    NASA Astrophysics Data System (ADS)

    Koga, K.; Muraki, Y.; Shibata, S.; Yamamoto, T.; Matsumoto, H.; Okudaira, O.; Kawano, H.; Yumoto, K.

    2013-12-01

    To support future space activities, it is crucial to acquire space environmental data related to the space-radiation degradation of space parts and materials, and spacecraft anomalies. Such data are useful for spacecraft design and manned space activity. SEDA-AP was mounted on 'Kibo' of the ISS (International Space Station) to measure the space environment at a 400-kilometer altitude. Neutrons are very harmful radiation, with electrical neutrality that makes them strongly permeable. SEDA-AP measures the energy of neutrons from thermal to 100 MeV in real time using a Bonner Ball Detector (BBND) and a Scintillation Fiber Detector (FIB). BBND detects neutrons using He-3 counters, which have high sensitivity to thermal neutrons. Neutron energy is derived using the relative response function of polyethylene moderators of 6 different thicknesses. FIB measures the tracks of recoil protons caused by neutrons within a cubic arrayed sensor of 512 scintillation fibers. The charged particles are excluded using an anti-scintillator which surrounds the cube sensor, and the neutron energy is obtained from the track length of a recoil proton. There are three sources of neutrons in space; 1. Albedo Neutrons Produced by reactions of galactic cosmic rays or radiation belt particles with the atmosphere 2. Local Neutrons Produced by the reactions of galactic cosmic rays or radiation belt particles with spacecraft 3. Solar Neutrons Produced by accelerated particles in solar flares An accurate energy spectrum of the solar neutrons includes important information on high-energy particle generation mechanism in a solar flare, because neutrons are unaffected by interplanetary magnetic fields. These data will become useful to forecast solar energetic particles in future. Some candidate events involving solar neutrons were found as a result of analyzing data of the solar flare of M>2 since September 2009. Moreover, it is important to measure albedo neutrons, since protons generated by neutron

  20. Neutron Monitor Observations and Space Weather, 1. Automatically Search of Great Solar Energetic Particle Event Beginning.

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Pustil'Nik, L. A.; Sternlieb, A.; Zukerman, I. G.

    It is well known that in periods of great SEP fluxes of energetic particles can be so big that memory of computers and other electronics in space may be destroyed, satellites and spacecrafts became dead: according to NOAA Space Weather Scales are danger- ous Solar Radiation Storms S5-extreme (flux level of particles with energy > 10 MeV more than 10^5), S4-severe (flux more than 10^4) and S3-strong (flux more than 10^3). In these periods is necessary to switch off some part of electronics for few hours to protect computer memories. These periods are also dangerous for astronauts on space- ships, and passengers and crew in commercial jets (especially during S5 storms). The problem is how to forecast exactly these dangerous phenomena. We show that exact forecast can be made by using high-energy particles (few GeV/nucleon and higher) which transportation from the Sun is characterized by much bigger diffusion coeffi- cient than for small and middle energy particles. Therefore high energy particles came from the Sun much more early (8-20 minutes after acceleration and escaping into so- lar wind) than main part of smaller energy particles caused dangerous situation for electronics (about 30-60 minutes later). We describe here principles and experience of automatically working of program "FEP-Search". The positive result which shows the exact beginning of FEP event on the Emilio Segre' Observatory (2025 m above sea level, Rc=10.8 GV), is determined now automatically by simultaneously increas- ing on 2.5 St. Dev. in two sections of neutron supermonitor. The next 1-min data the program "FEP-Search" uses for checking that the observed increase reflects the begin- ning of real great FEP or not. If yes, automatically starts to work on line the programs "FEP-Research".

  1. Monitoring and forecasting of radiation hazard from great solar energetic particle events by using on-line one-min neutron monitor and satellite data.

    PubMed

    Dorman, Lev I

    2007-01-01

    The method of automatically determining the start of great solar energetic particle (SEP) events are described on the basis of cosmic ray (CR) one-min observations by neutron monitors in real-time scale. It is shown that the probabilities of false alarms and missed triggers are negligible. After the start of SEP event, it is automatically determined by the method of coupling functions the SEP energy spectrum and flux for each minute of observations. By solving the inverse problem during few first minutes of SEP event, diffusion coefficient in the interplanetary space, source function on the Sun, and time of ejection of SEP into solar wind are determined. For extending obtained results into small energy range we use also available from Internet the satellite one-min CR data. This make possible to give forecast of space-time variation of SEP for more than 2 days and estimate expected radiation dose for satellite and aircrafts. With each new minute of observations, the quality of forecast increased, and after approximately 30 min became near 100%.

  2. Development of monitoring method of spatial neutron distribution in neutrons-gamma rays mixed field using imaging plate for NCT--depression of the field.

    PubMed

    Tanaka, Kenichi; Endo, Satoru; Hoshi, Masaharu; Takada, Jun

    2011-12-01

    The degree of depression in the neutron field caused by neutron absorption in the materials of an imaging plate (IP) was investigated using MCNP-4C. Consequently, the IP doped with Gd, which reproduced the distribution of (157)Gd(n,γ)(158)Gd reaction rate in the previous study, depresses the relative distribution by about 50%. The depression for the IP in which Gd is replaced with similar amount of B atoms was estimated to be about 10%. The signal intensity for this IP is estimated to be at a similar level with that for Gd-doped IP.

  3. Space Environmental Viewing and Analysis Network (SEVAN) - A Network of Neutron Monitors in Bulgaria

    NASA Astrophysics Data System (ADS)

    Georgieva, K.

    2006-11-01

    katyagerogieva@msn.com A network of middle to low latitude particle detectors called SEVAN (Space Environmental Viewing and Analysis Network) aims to improve fundamental research of the space weather conditions and provide possibilities to perform short and long-term forecasts of the dangerous consequences of the space storms. The network will detect changing fluxes of the most species of secondary cosmic rays at different altitudes and latitudes, thus constituting powerful integrated device in exploring solar modulation effects. Recently two more countries have decided to host cosmic ray monitors - Bulgaria and Croatia.

  4. The solar modulation potential derived by spacecraft measurements modified to describe GCRs also at rigidites below neutron monitors

    NASA Astrophysics Data System (ADS)

    Gieseler, Jan; Herbst, Konstantin; Kühl, Patrick; Heber, Bernd

    2016-07-01

    On their way through the heliosphere Galactic Cosmic Rays (GCRs) are modulated by various effects before they can be detected at Earth. This process can be described by the Parker equation, which calculates the phase space distribution of GCRs depending on the main modulation processes: convection, drifts, diffusion and adiabatic energy changes. A first order approximation of this equation is the force field approach, reducing it to a one-parameter dependency, the solar modulation potential φ. Utilizing this approach, Usoskin et al. (2005; 2011) reconstructed φ for the time from 1936 to 2010, which by now is commonly used in many fields. However, it has been shown previously (e.g. by Herbst et al., 2010) that φ depends not only on the Local Interstellar Spectrum (LIS) but also on the rigidity range of interest. We have investigated this energy dependence further, using published proton intensity spectra obtained by PAMELA, heavier nuclei measurements from IMP8 and ACE/CRIS, and neutron monitor observations. In addition, we take advantage of a newly established LIS based on direct Voyager observations (Bisschoff and Potgieter, 2016). We will present the results that show as expected severe limitations at lower energies including a strong dependence on the solar magnetic epoch. Based on these findings, we will outline a tool to describe GCR proton spectra in the energy range from a few hundred MeV to tens of GeV over the last solar cycles.

  5. Interactions of Endoglucanases with Amorphous Cellulose Films Resolved by Neutron Reflectometry and Quartz Crystal Microbalance with Dissipation Monitoring

    SciTech Connect

    Cheng, Gang; Liu, Zelin; Kent, Michael S; Majewski, Jaroslaw; Michael, Jablin; Jaclyn, Murton K; Halbert, Candice E; Datta, Supratim; Chao, Wang; Brown, Page

    2012-01-01

    A study of the interaction of four endoglucanases with amorphous cellulose films by neutron reflectometry (NR) and quartz crystal microbalance with dissipation monitoring (QCM-D) is reported. The endoglucanases include a mesophilic fungal endoglucanase (Cel45A from H. insolens), a processive endoglucanase from a marine bacterium (Cel5H from S. degradans), and two from thermophilic bacteria (Cel9A from A. acidocaldarius and Cel5A from T. maritima). The use of amorphous cellulose is motivated by the promise of ionic liquid pretreatment as a second generation technology that disrupts the native crystalline structure of cellulose. The endoglucanases displayed highly diverse behavior. Cel45A and Cel5H, which possess carbohydrate-binding modules (CBMs), penetrated and digested within the bulk of the films to a far greater extent than Cel9A and Cel5A, which lack CBMs. While both Cel45A and Cel5H were active within the bulk of the films, striking differences were observed. With Cel45A, substantial film expansion and interfacial broadening were observed, whereas for Cel5H the film thickness decreased with little interfacial broadening. These results are consistent with Cel45A digesting within the interior of cellulose chains as a classic endoglucanase, and Cel5H digesting predominantly at chain ends consistent with its designation as a processive endoglucanase.

  6. Personnel radiation dosimetry symposium: program and abstracts

    SciTech Connect

    Not Available

    1984-10-01

    The purpose was to provide applied and research dosimetrists with sufficient information to evaluate the status and direction of their programs relative to the latest guidelines and techniques. A technical program was presented concerning experience, requirements, and advances in gamma, beta, and neutron personnel dosimetry.

  7. Computer-controlled radiation monitoring system

    SciTech Connect

    Homann, S.G.

    1994-09-27

    A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory`s Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past five years, and has been a valuable tool for maintaining personnel exposure as low as reasonably achievable.

  8. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  9. Semiconductor neutron detector

    DOEpatents

    Ianakiev, Kiril D.; Littlewood, Peter B.; Blagoev, Krastan B.; Swinhoe, Martyn T.; Smith, James L.; Sullivan, Clair J.; Alexandrov, Boian S.; Lashley, Jason Charles

    2011-03-08

    A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

  10. LANSCE personnel access control system

    SciTech Connect

    Sturrock, J.C.; Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described.

  11. Sensitivity of single and multiple cosmic ray neutrons to the surrounding medium in a lead-free monitor

    NASA Technical Reports Server (NTRS)

    Dorman, I. V.; Dorman, L. T.; Libin, T. Y.; Korotkov, V. K.

    1985-01-01

    In 1981-1985 the neutron component of cosmic rays was recorded, the effect of cosmic ray multiplication in lead being disregarded. The recording device consisted of neutron counters placed in a polyethylene retarder (polyethylene tubes with wall thickness of 2 cm). The device registered neutrons formed directly on the surface or not deep underground; the intensity of neutrons depended on the chemical composition of the substance. The neutron component was also measured in the Moscow Canal, Belomor-Baltic Canal, and in the Atlantic Ocean. The time variation of 5 minute data of the intensity obtained in the Belomor-Baltic Canal and in the Atlantic Ocean relative to the mean value in the open sea (in %) is presented.

  12. Los Alamos personnel and area criticality dosimeter systems

    SciTech Connect

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

    1981-06-01

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

  13. Application of low-cost Gallium Arsenide light-emitting-diodes as kerma dosemeter and fluence monitor for high-energy neutrons.

    PubMed

    Mukherjee, B; Simrock, S; Khachan, J; Rybka, D; Romaniuk, R

    2007-01-01

    Displacement damage (DD) caused by fast neutrons in unbiased Gallium Arsenide (GaAs) light emitting diodes (LED) resulted in a reduction of the light output. On the other hand, a similar type of LED irradiated with gamma rays from a (60)Co source up to a dose level in excess of 1.0 kGy (1.0 x 10(5) rad) was found to show no significant drop of the light emission. This phenomenon was used to develop a low cost passive fluence monitor and kinetic energy released per unit mass dosemeter for accelerator-produced neutrons. These LED-dosemeters were used to assess the integrated fluence of photoneutrons, which were contaminated with a strong bremsstrahlung gamma-background generated by the 730 MeV superconducting electron linac driving the free electron laser in Hamburg (FLASH) at Deutsches Elektronen-Synchrotron. The applications of GaAs LED as a routine neutron fluence monitor and DD precursor for the electronic components located in high-energy accelerator environment are highlighted.

  14. Guidelines for the calibration of personnel dosimeters

    SciTech Connect

    Roberson, P.L.; Holbrook, K.L.

    1984-01-01

    This guide describes minimum acceptable performance levels for personnel dosimetry systems used at Department of Energy (DOE) facilities. The goal is to improve both the quality of radiological calibrations and the methods of comparing reported occupational doses between DOE facilities. Reference calibration techniques are defined. A standard for evaluation of personnel dosimetry systems and recommended design parameters for personnel dosimeters are also included. Approximate intervals for the radiation energies for which these guidelines are appropriate are 15 keV to 2 MeV for photons; above 0.3 MeV for beta particles; and 1 keV to 2 MeV for neutrons. An analysis of ANSI N13.11 was completed using performance evaluations of selected personnel dosimetry systems in use at DOE facilities. The results of this analysis are incorporated in the guidelines.

  15. SU-E-T-249: Neutron Model Upgrade for Radiotherapy Patients Monitoring Using a New Online Detector

    SciTech Connect

    Irazola, L; Sanchez Doblado, F.; Lorenzoli, M; Pola, A.; Terron, J.A.; Bedogni, R.; Sanchez Nieto, B.; Romero-Exposito, M.

    2014-06-01

    Purpose: The purpose of this work is to improve the existing methodology to estimate neutron equivalent dose in organs during radiotherapy treatments, based on a Static Random Access Memory neutron detector (SRAMnd) [1]. This is possible thanks to the introduction of a new digital detector with improved characteristics, which is able to measure online the neutron fluence rate in the presence of an intense photon background [2]. Its reduced size, allows the direct estimation of doses in specific points inside an anthropomorphic phantom (NORMA) without using passive detectors as TLD or CR-39. This versatility will allow not only to improve the existing models (generic abdomen and H and N [1]) but to generate more specific ones for any technique. Methods: The new Thermal Neutron Rate Detector (TNRD), based on a diode device sensitized to thermal neutrons, have been inserted in 16 points of the phantom. These points are distributed to infer doses to specific organs. Simultaneous measurements of these devices and a reference one, located in front of the gantry, have been performed for the mentioned generic treatments, in order to improve the existing model. Results: These new devices have shown more precise since they agree better with Monte Carlo simulations. The comparison of the thermal neutron fluence, measured with TNRD, and the existing models, converted from events to fluence, shows an average improvement of (3.90±3.37) % for H and N and (12.61±9.43) % for abdomen, normalized to the maximum value. Conclusion: This work indicates the potential of these new devices for more precise neutron equivalent dose estimation in organs, as a consequence of radiotherapy treatments. The simplicity of the process makes possible to establish more specific models that will provide a better dose estimation. References[1] Phys Med Biol 2012; 57:6167–6191.[2] A new active thermal neutron detector. Radiat. Prot. Dosim. (in press)

  16. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

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

  17. Progress in the development of the neutron flux monitoring system of the French GEN-IV SFR: simulations and experimental validations [ANIMMA--2015-IO-392

    SciTech Connect

    Jammes, C.; Filliatre, P.; Izarra, G. de; Elter, Zs.; Verma, V.; Hamrita, H.; Bakkali, M.; Chapoutier, N.; Scholer, A.C.; Verrier, D.; Hellesen, C.; Jacobsson, S.; Pazsit, I.; Cantonnet, B.; Nappe, J.C.; Molinie, P.; Dessante, P.; Hanna, R.; Kirkpatrick, M.; Odic, E.

    2015-07-01

    France has a long experience of about 50 years in designing, building and operating sodium-cooled fast reactors (SFR) such as RAPSODIE, PHENIX and SUPER PHENIX. Fast reactors feature the double capability of reducing nuclear waste and saving nuclear energy resources by burning actinides. Since this reactor type is one of those selected by the Generation IV International Forum, the French government asked, in the year 2006, CEA, namely the French Alternative Energies and Atomic Energy Commission, to lead the development of an innovative GEN-IV nuclear- fission power demonstrator. The major objective is to improve the safety and availability of an SFR. The neutron flux monitoring (NFM) system of any reactor must, in any situation, permit both reactivity control and power level monitoring from startup to full power. It also has to monitor possible changes in neutron flux distribution within the core region in order to prevent any local melting accident. The neutron detectors will have to be installed inside the reactor vessel because locations outside the vessel will suffer from severe disadvantages; radially the neutron shield that is also contained in the reactor vessel will cause unacceptable losses in neutron flux; below the core the presence of a core-catcher prevents from inserting neutron guides; and above the core the distance is too large to obtain decent neutron signals outside the vessel. Another important point is to limit the number of detectors placed in the vessel in order to alleviate their installation into the vessel. In this paper, we show that the architecture of the NFM system will rely on high-temperature fission chambers (HTFC) featuring wide-range flux monitoring capability. The definition of such a system is presented and the justifications of technological options are brought with the use of simulation and experimental results. Firstly, neutron-transport calculations allow us to propose two in-vessel regions, namely the above-core and under

  18. Monitoring water storage changes using absolute gravity measurements, neutron probes and piezometer data in West Africa: advances in specific yield and recharge estimation

    NASA Astrophysics Data System (ADS)

    Hector, B.; Séguis, L.; Descloîtres, M.; Hinderer, J.; Wubda, M.; Luck, B.; Le Moigne, N.

    2012-04-01

    Advances in water storage monitoring are crucial to characterize the spatial variability of hydrological processes. Classical water storage investigation methods often involve point measurements (piezometers, neutron probes, humidity sensors…), which may be irrelevant in heterogeneous mediums. Over the past few years, there has been an increasing interest in the use of gravimeters for hydrological studies. Water mass redistribution leads to variations in the Earth's gravity field which can be measured by gravimetry. In the framework of the GHYRAF (Gravity and Hydrology in Africa) project, 3 years of repeated absolute gravity measurements using FG5#206 from Micro-g Solutions Inc. have been undertaken at Nalohou, a Sudanian site in northern Benin. Hydrological monitoring is carried out within the long-term observing system AMMA-Catch (an observatory of RBV, the French critical zone exploration network). Seasonal gravity variations in link with the hydrological cycle can reach 11 µgal at this site, equivalent to a 26cm thick infinite layer of water. The vadose zone and a shallow unconfined aquifer in weathered metamorphic rocks are responsible for most of the water storage variations. For the first time in the climatic context of the West African monsoon, gravity data are compared to the time evolution of the water storages deduced from neutron probes and water-table variations. The approach is two-fold: first, total storage variations are estimated from neutron probe-derived moisture through the whole vertical profile (surface to groundwater) monitored at the gravimetric site and uniformly extended according to the topography. Results show a very good fit with gravity data, enlightening the fact that absolute gravimeters are sensitive to total water storage variations from the soil surface to the aquifer. The second approach introduces a spatial variability: it was undertaken to check a structural model for specific yield of the aquifer, based on magnetic

  19. Towards the use of gravity data for monitoring water storage changes: results from a comparison with neutron probes and piezometers data in West Africa

    NASA Astrophysics Data System (ADS)

    Hector, B.; Hinderer, J.; Séguis, L.; Descloitres, M.; Wubda, M.; Luck, B.; Le Moigne, N.

    2011-12-01

    Advances in water storage monitoring are crucial to characterize the spatial variability of hydrological processes. Classical water storage investigation methods often involve point measurements (piezometers, neutron probes, humidity sensors...), which may be irrelevant in heterogeneous mediums. Over the past few years, there has been an increasing interest in the use of gravimeters for hydrological studies. Water mass redistribution leads to variations in the Earth's gravity field which can be measured by gravimetry. In the framework of the GHYRAF (Gravimetry and Hydrology in Africa) project, 3 years of repeated absolute gravity measurements have been undertaken at Nalohou, a Sudanian site in northern Benin. Hydrological monitoring is carried out within the long-term observing system AMMA-Catch (an observatory of RBV, the French critical zone exploration network). Seasonal gravity variations in link with the hydrological cycle can reach 11 μgal at this site, equivalent to a 26cm thick infinite layer of water. The vadose zone and a shallow unconfined aquifer in weathered metamorphic rocks are responsible for most of the water storage. For the first time in the climatic context of the West African monsoon, gravity data are compared to the time evolution of the water storages deduced from neutron probes and water-table variations. The approach is two-fold: first, total storage variations are estimated from neutron probe-derived moisture through the whole vertical profile monitored at the gravimetric site and uniformly extended according to the topography. Results show a very good fit with gravity data, enlightening the fact that absolute gravimeters are sensitive to total water storage variations from the soil surface to the aquifer. The second approach introduces a spatial variability: it was undertaken to check a structural model for specific yield of the aquifer, based on magnetic resonance soundings (MRS) and spatialized with resistivity data (TDEM). We

  20. Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

    NASA Astrophysics Data System (ADS)

    Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara

    2015-07-01

    We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

  1. Application of magnetomechanical hysteresis modeling of magnetic techniques for monitoring neutron embrittlement and biaxial stress. First year report, June 1991--June 1992

    SciTech Connect

    Sablik, M.J.; Kwun, H.; Burkhardt, G.L.; Rollwitz, W.L.; Cadena, D.G.

    1993-01-31

    Objective of this project is to investigate experimentally and theoretically the effects of neutron embrittlement and biaxial stress on magnetic properties in steels, using various magnetic measurement techniques. If neutron embrittlement and biaxial stress can be measured via changes in magnetic properties, this should ultimately assist in safety monitoring of nuclear power plants and of gas and oil pipelines. This first-year report addresses the issue of using magnetic property changes to detect neutron embrittlement. The magnetic measurements were all done on irradiated specimens previously broken in two in a Charpy test to determine their embrittlement. The magnetic properties of the broken charpy specimens from D.C. Cook did not correlate well with fluence or embrittlement parameters, possible due to metallurgical reasons. correlation was better with Indian Point 2 specimens, with the nonlinear harmonic amplitudes showing the best correlation (R{sup 2}{approximately}0.7). However, correlation was not good enough. It is recommended that tests be done on unbroken irradiated Charpy specimens, for which magnetic characterization data prior to irradiation is available, if possible.

  2. Hanford personnel dosimeter supporting studies FY-1981

    SciTech Connect

    Not Available

    1982-08-01

    This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies.

  3. ATR neutron spectral characterization

    SciTech Connect

    Rogers, J.W.; Anderl, R.A.

    1995-11-01

    The Advanced Test Reactor (ATR) at INEL provides intense neutron fields for irradiation-effects testing of reactor material samples, for production of radionuclides used in industrial and medical applications, and for scientific research. Characterization of the neutron environments in the irradiation locations of the ATR has been done by means of neutronics calculations and by means of neutron dosimetry based on the use of neutron activation monitors that are placed in the various irradiation locations. The primary purpose of this report is to present the results of an extensive characterization of several ATR irradiation locations based on neutron dosimetry measurements and on least-squares-adjustment analyses that utilize both neutron dosimetry measurements and neutronics calculations. This report builds upon the previous publications, especially the reference 4 paper. Section 2 provides a brief description of the ATR and it tabulates neutron spectral information for typical irradiation locations, as derived from the more historical neutron dosimetry measurements. Relevant details that pertain to the multigroup neutron spectral characterization are covered in section 3. This discussion includes a presentation on the dosimeter irradiation and analyses and a development of the least-squares adjustment methodology, along with a summary of the results of these analyses. Spectrum-averaged cross sections for neutron monitoring and for displacement-damage prediction in Fe, Cr, and Ni are given in section 4. In addition, section4 includes estimates of damage generation rates for these materials in selected ATR irradiation locations. In section 5, the authors present a brief discussion of the most significant conclusions of this work and comment on its relevance to the present ATR core configuration. Finally, detailed numerical and graphical results for the spectrum-characterization analyses in each irradiation location are provided in the Appendix.

  4. Neutron spectra and dose-rate measurements around a transport cask for spent reactor fuel

    NASA Astrophysics Data System (ADS)

    Rimpler, Arndt

    1997-02-01

    A storage facility with a capacity of 420 containers is available for the interim storage of spent fuel from power reactors at the village of Gorleben in Germany. During transportation and storage of spent fuel casks radiation exposure of the personnel is dominated by neutrons. The routine control of the dose rate limits according to the transport regulations and the licence of the storage facility is performed with conventional neutron survey meters. These monitors, calibrated for fast neutrons at radionuclide neutron sources, usually overestimate the real dose rate in unknown neutron fields. In this paper, a series of measurements with several monitoring instruments near a transport cask of the CASTOR type is presented. The results are compared with reference data for the does equivalents calculated from the measured fluence spectra using a Bonner multisphere spectrometer. Besides reliable information about neutron spectra and dose rates at the container, it was found that some of the rem counters overestimate the true dose rate by a factor of 2 or more.

  5. 76 FR 52533 - Personnel Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Official Personnel Folders of Federal employees to clarify the roles and responsibilities of OPM and... Federal Regulations (Personnel Records) to clarify agency responsibilities concerning Official Personnel... the other agencies share responsibility for personnel management in the Executive Branch....

  6. Coated Fiber Neutron Detector Test

    SciTech Connect

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

    2009-10-23

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

  7. Application of magnetomechanical hysteresis modeling to magnetic techniques for monitoring neutron embrittlement and biaxial stress. Progress report, June 1991--December 1991

    SciTech Connect

    Sablik, M.J.; Kwun, H.; Rollwitz, W.L.; Cadena, D.

    1992-01-01

    The objective is to investigate experimentally and theoretically the effects of neutron embrittlement and biaxial stress on magnetic properties in steels, using various magnetic measurement techniques. Interaction between experiment and modeling should suggest efficient magnetic measurement procedures for determining neutron embrittlement biaxial stress. This should ultimately assist in safety monitoring of nuclear power plants and of gas and oil pipelines. In the first six months of this first year study, magnetic measurements were made on steel surveillance specimens from the Indian Point 2 and D.C. Cook 2 reactors. The specimens previously had been characterized by Charpy tests after specified neutron fluences. Measurements now included: (1) hysteresis loop measurement of coercive force, permeability and remanence, (2) Barkhausen noise amplitude; and (3) higher order nonlinear harmonic analysis of a 1 Hz magnetic excitation. Very good correlation of magnetic parameters with fluence and embrittlement was found for specimens from the Indian Point 2 reactor. The D.C. Cook 2 specimens, however showed poor correlation. Possible contributing factors to this are: (1) metallurgical differences between D.C. Cook 2 and Indian Point 2 specimens; (2) statistical variations in embrittlement parameters for individual samples away from the stated men values; and (3) conversion of the D.C. Cook 2 reactor to a low leakage core configuration in the middle of the period of surveillance. Modeling using a magnetomechanical hysteresis model has begun. The modeling will first focus on why Barkhausen noise and nonlinear harmonic amplitudes appear to be better indicators of embrittlement than the hysteresis loop parameters.

  8. Chaplain Personnel Information Guide

    DTIC Science & Technology

    1991-04-15

    documnt may not be Mased for opem pisbiktao. si it hu been deajed by the appropiate miitay svice ot oervmnent qaeny. CHAPLAIN PERSONNEL INFORMATION GUIDE ...Include Security Classification) Chaplain Personnel Information Guide 12 PERSONAL AUTHOR(S) Chaplain (LTC) Jerry W. Black 13a. TYPE OF REPORT 13b...personnel information guide called the "Red Book." This guide contains information papers that are updated annually on subjects frequently discussed among the

  9. Neutron and high-contrast X-ray micro-radiography as complementary tools for monitoring organosilicon consolidants in natural building stones

    NASA Astrophysics Data System (ADS)

    Slavíková, Monika; Krejčí, František; Kotlík, Petr; Jakůbek, Jan; Tomandl, Ivo; Vacík, Jiří

    2014-11-01

    The monitoring of consolidants and other treatment product in stones is currently of great importance in various restoration studies. We use neutron and high-contrast X-ray micro-radiography as complementary non-destructive techniques for monitoring of organosilicon consolidants in the Opuka stone. Thanks to different sensitivities of both techniques in relation to the elemental composition, the effect of addition of the contrast agent (3-iodopropyl)trimethoxysilane commonly used in stone consolidation monitoring with X-ray radiography is evaluated. As the addition of the contrast agent to the original consolidation product alters important parameters such as the penetration depth, the understanding of the behaviour of the modified consolidation mixture is essential for verification of the reliability of the method. By comparing results from both methods, the respective radiographs show consistency in terms of homogeneity and penetration depth for all investigated concentrations of the used contrast agent. The presented results further demonstrate that the application of the contrast agent apparently changes the penetration depth, but these changes are, especially for very low concentrations (up to 1%) for most of the studies needed, negligible.

  10. Magnetospheric effects of cosmic rays. 1. Long-term changes in the geomagnetic cutoff rigidities for the stations of the global network of neutron monitors

    NASA Astrophysics Data System (ADS)

    Gvozdevskii, B. B.; Abunin, A. A.; Kobelev, P. G.; Gushchina, R. T.; Belov, A. V.; Eroshenko, E. A.; Yanke, V. G.

    2016-07-01

    Vertical geomagnetic cutoff rigidities are obtained for the stations of the global network of neutron monitors via trajectory calculations for each year of the period from 1950 to 2020. Geomagnetic cutoff rigidities are found from the model of the Earth's main field International Geomagnetic Reference Field (IGRF) for 1950-2015, and the forecast until 2020 is provided. In addition, the geomagnetic cutoff rigidities for the same period are obtained by Tsyganenko model T89 (Tsyganenko, 1989) with the average annual values of the Kp-index. In each case, the penumbra is taken into account in the approximation of the flat and power spectra of variations of cosmic rays. The calculation results show an overall decrease in geomagnetic cutoff rigidities, which is associated with the overall decrease and restructuring of the geomagnetic field during the reporting period, at almost all points.

  11. Neutron diagnostics at the Wendelstein 7-X stellarator

    NASA Astrophysics Data System (ADS)

    Schneider, W.; Wiegel, B.; Grünauer, F.; Burhenn, R.; Koch, S.; Schuhmacher, H.; Zimbal, A.

    2012-03-01

    The stellarator W7-X, presently under construction at the Institute for Plasma Physics in Greifswald, will be equipped with a set of neutron monitors in order to study the time behaviour of neutron emission generated during D-D plasma operation and neutral beam heating with Deuterium. Each of these neutron monitors consists of several neutron detector tubes inserted in a dedicated moderator. The neutron monitors at W7-X are designed to monitor neutron yields with a time resolution of 5 ms and with a statistical uncertainty of better than 15%. One of the monitors is located in the centre above the stellarator. The other five monitors are distributed around the torus. A prerequisite for the determination of the absolute neutron source strength produced by D(d,n)3He fusion reactions in the plasma is an in-situ calibration with a neutron source of known source strength. During such a calibration procedure, the neutron source will be moved along the torus axis and the count rates of the different neutron monitors will be measured. In a first benchmark experiment, an 241AmBe neutron source was moved along the torus axis within one module of the stellarator and the neutron signals were measured by a De Pangher Long Counter outside of the cryostat chamber as a function of the neutron source position. These measurements have been compared with predictions of Monte Carlo calculations (MCNP) of the neutron propagation from the location of the neutron source to the long counter. The concept of neutron monitors will be reported together with results from the benchmark experiment and results from MCNP calculations. The neutron monitor system is the first part of several neutron diagnostic systems such as neutron activation system, neutron profile camera planned for future neutron analysis. A short survey of these neutron diagnostic tools of W7-X will be given.

  12. Pulsed neutron detector

    DOEpatents

    Robertson, deceased, J. Craig; Rowland, Mark S.

    1989-03-21

    A pulsed neutron detector and system for detecting low intensity fast neutron pulses has a body of beryllium adjacent a body of hydrogenous material the latter of which acts as a beta particle detector, scintillator, and moderator. The fast neutrons (defined as having En>1.5 MeV) react in the beryllium and the hydrogenous material to produce larger numbers of slow neutrons than would be generated in the beryllium itself and which in the beryllium generate hellium-6 which decays and yields beta particles. The beta particles reach the hydrogenous material which scintillates to yield light of intensity related to the number of fast neutrons. A photomultiplier adjacent the hydrogenous material (scintillator) senses the light emission from the scintillator. Utilization means, such as a summing device, sums the pulses from the photo-multiplier for monitoring or other purposes.

  13. Personnel Management Institutes, 1975.

    ERIC Educational Resources Information Center

    Hinman, Stanley B., Jr., Comp.

    This publication is a compilation of five papers presented at the 1975 Personnel Management Institutes held by the New York State School Boards Association. Although the meeting was intended to provide useful information about personnel matters specifically for school board members and school administrators from New York, much of the content of…

  14. Student Personnel "Educators."

    ERIC Educational Resources Information Center

    Knott, J. Eugene

    It is suggested that student personnel workers in higher education have comparable responsibilities to their academic counterparts as "educators" in a literal sense. Each contact with a student by personnel officers should be viewed as an opportunity for facilitating learning and growth. As such, a responsibility for being conversant with and open…

  15. Projecting Personnel Needs.

    ERIC Educational Resources Information Center

    Kelly, Philip T.

    Increased reliance on personnel services is placing school districts' business operations in a no-win situation. This report evaluates methods of student population projection in relation to teacher costs. Educational costs reflect personnel costs in light of a decrease in the number of pupils being served. Increased enrollment projections create…

  16. Cosmic Rays and Dynamical Meteorology, 2. Snow Effect In Different Multiplicities According To Neutron Monitor Data of Emilio Segre' Observatory

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Iucci, N.; Pustil'Nik, L. A.; Sternlieb, A.; Villoresi, G.; Zukerman, I. G.

    On the basis of cosmic ray hourly data obtained by NM of Emilio Segre' Observatory (hight 2025 m above s.l., cut-off rigidity for vertical direction 10.8 GV) we determine the snow effect in CR for total neutron intensity and for multiplicities m=1, m=2, m=3, m=4, m=5, m=6, and m=7. For comparison and excluding primary CR variations we use also hourly data on neutron multiplicities obtained by Rome NM (about sea level, cut-off rigidity 6.7 GV). In this paper we will analize effects of snow in periods from 4 January 2000 to 15 April 2000 with maximal absorption effect about 5%, and from 21 December 2000 up to 31 March 2001 with maximal effect 13% in the total neu- tron intensity. We use the periods without snow to determine regeression coefficients between primary CR variations observed by NM of Emilio Segre' Observatory, and by Rome NM. On the basis of obtained results we develop a method to correct data on snow effect by using several NM hourly data. On the basis of our data we estimate the accuracy with what can be made correction of NM data of stations where the snow effect can be important.

  17. NEUTRONIC REACTOR

    DOEpatents

    Ohlinger, L.A.; Wigner, E.P.; Weinberg, A.M.; Young, G.J.

    1958-09-01

    This patent relates to neutronic reactors of the heterogeneous water cooled type, and in particular to a fuel element charging and discharging means therefor. In the embodiment illustrated the reactor contains horizontal, parallel coolant tubes in which the fuel elements are disposed. A loading cart containing a magnzine for holding a plurality of fuel elements operates along the face of the reactor at the inlet ends of the coolant tubes. The loading cart is equipped with a ram device for feeding fuel elements from the magazine through the inlot ends of the coolant tubes. Operating along the face adjacent the discharge ends of the tubes there is provided another cart means adapted to receive irradiated fuel elements as they are forced out of the discharge ends of the coolant tubes by the incoming new fuel elements. This cart is equipped with a tank coataining a coolant, such as water, into which the fuel elements fall, and a hydraulically operated plunger to hold the end of the fuel element being discharged. This inveation provides an apparatus whereby the fuel elements may be loaded into the reactor, irradiated therein, and unloaded from the reactor without stopping the fiow of the coolant and without danger to the operating personnel.

  18. 75 FR 2821 - Personnel Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ...; ] OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 293 RIN 3206-AM05 Personnel Records AGENCY: U.S. Office of Personnel Management. ACTION: Proposed rule with request for comments. SUMMARY: The U.S. Office of Personnel Management (OPM) is proposing to amend the regulations governing disposition of Official Personnel Folders...

  19. Using a multi-parameter monitoring methodology to predict failures in the cryogenic plant of the cold neutron source at Australia's OPAL reactor

    NASA Astrophysics Data System (ADS)

    Lu, Weijian; Thiering, Russell

    2012-06-01

    A 5 kW Brayton-cycle helium refrigeration plant provides cooling at 20 K to the Cold Neutron Source (CNS) at Australia's OPAL Reactor. During several years of operation to the present day, the plant has experienced an unusually high number of turbine and compressor failures. The root cause for some of the failures is known, but for others remains to be determined. All of the failures were catastrophic without any prior warning from standard industrial monitoring based on singular process variables such as temperature, pressure and vibration. The failures and the down time they caused have been very costly. As the operator of the plant, we have developed a multi-parameter monitoring (MPM) methodology to track the performance of the plant. The methodology utilises indicators obtained from a combination of process variables based on their thermodynamic relations. By studying the historical trends of appropriate indicators, especially during the past failures, we have found some indicators that would be able to improve our predictive capability so that we can avoid similar failures in the future.

  20. Application of cosmic-ray neutron sensing to monitor soil water content in an alpine meadow ecosystem on the northern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Zhu, Xuchao; Shao, Ming'an; Zeng, Chen; Jia, Xiaoxu; Huang, Laiming; Zhang, Yangjian; Zhu, Juntao

    2016-05-01

    Cosmic-ray neutron sensing (CRNS) is a new method for continuously monitoring mean soil water content (SWC) on a hectometer scale. To evaluate the application and accuracy of the method for SWC observation in an alpine meadow ecosystem (AME), we installed the CRNS in a flat meadow near the Naqu prefecture on the northern Tibetan Plateau. We collecting soil samples and applying the system by the oven-drying method. A weather station was also installed near the CRNS for monitoring basic meteorological variables and the soil temperature and water content at various depths. Three Em-50 instruments for monitoring SWC and soil temperature were buried in three sub-quadrats northwest, northeast and southeast of the CRNS at distances of 460, 370 and 373 m, respectively, to observe the variation of SWC at the various depths. The footprint of the CRNS for SWC observation in the meadow was about 580 m, and the mean measuring depth was about 31 cm according to the general calculation equations. The reference neutron flux for dry soil (N0) had a mean and coefficient of variation of 8686 and 3%, respectively, and remained substantially invariant throughout the measuring period. The five SWCs from the independent field samples almost passed through the SWC trend of the CRNS, the root mean square error (RMSE) was 0.011 m3 m-3 for the CRNS and oven-drying method. The time series of SWC measured by the CRNS agreed well with the mean SWC series to a depth of 20 cm measured by the weather station. The trend of SWC measured by the Em-50s generally agreed with the trend of SWC measured by the CRNS, but some values and variations of SWC differed between the Em-50s and CRNS data. Because of the good agreement between the CRNS and independent field samples, we suspect that this disagreement is due to an insufficient representativeness of point observations and the distances of the points from the CRNS. The diurnal variation of hourly SWC from the CRNS was sinusoidal during a dry period

  1. Monitoring of the time and spatial distribution of neutron-flux spectral density outside the Russian segment of the International Space Station based on data from the BTN-Neutron space experiment

    NASA Astrophysics Data System (ADS)

    Litvak, M. L.; Mitrofanov, I. G.; Nuzhdin, I. O.; Vostrukhin, A. V.; Golovin, D. V.; Kozyrev, A. S.; Malakhov, A. V.; Mokrousov, M. I.; Sanin, A. B.; Tretyakov, V. I.; Fedosov, F. S.

    2017-03-01

    Results of measurements of neutron-flux spectral density in the vicinity of the International Space Station (ISS) based on BTN-Neutron space experimental data acquired in 2007-2014 have been presented in this paper. It has been shown that, during the flight of the ISS over different regions of the Earth's surface, neutron flux in the energy range of 0.4 eV-15 MeV varies from 0.1 n/sm2/s in equatorial regions to 50 n/sm2/s in the South Atlantic anomaly region. The measurements were used to estimate the contribution of the neutron component to the overall exposure dose rate. The total contribution of fast neutrons is about 0.1-0.4 μ Zv/h above the equator area and more than 50 μ Zv/h above the South Atlantic anomaly region. A data analysis of BTN-Neutron data also showed that the time profile of neutron flux has long-periodic variations. It was found that, under the influence of Galactic cosmic rays (GCRs), modulation during 24th solar cycle neutron flux changed almost twofold (above high latitude regions). Maximum values of neutron flux were observed in January 2010 and minimum values were observed in January 2014.

  2. Application of high performance liquid chromatography/tandem mass spectrometry in the environmental and biological monitoring of health care personnel occupationally exposed to cyclophosphamide and ifosfamide.

    PubMed

    Minoia, C; Turci, R; Sottani, C; Schiavi, A; Perbellini, L; Angeleri, S; Draicchio, F; Apostoli, P

    1998-01-01

    Twenty four workers (10 involved in the preparation and 14 in administration) exposed to cyclophosphamide (CP) and ifosfamide (IF) in two Italian hospitals were monitored. The extent of exposure was assessed by the analysis of air samples, wipe samples, pads and gloves. Urinary excretion at the beginning and at the end of the work shift was also measured by liquid-liquid extraction and analysis by high performance liquid chromatography/tandem mass spectrometry. Three out of 24 air samples were positive for CP or IF. In wipe samples, CP concentrations ranging from < 0.001 to 82.4 micrograms/dm2 in Hospital A (32 samples) and from 0.2 to 383.3 micrograms/dm2 in Hospital B (17 samples), were found. IF concentrations varied from < 0.001 to 90.9 micrograms/dm2 in Hospital A and from 0.01 to 141.5 micrograms/dm2 in Hospital B. Pads (from 11 to 13 for each operator) were contaminated with CP and IF especially on arms, legs and chest. The use of a plastic-backed liner on the working tray in the laminar flow hoods was demonstrated to compromise the containment properties of the hood. Urine samples were positive for CP in 50% of the workers (range: 0.1-2.1 micrograms/L), whereas IF was detected in 2 subjects only (range: 0.1-0.8 microgram/L). The results of this investigation demonstrate that vertical laminar airflow hoods, when incorrectly used, might represent a source of contamination and that higher risk may depend on lack of educational programmes and observance of preventive guidelines.

  3. Biases encountered in long-term monitoring studies of invertebrates and microflora: Australian examples of protocols, personnel, tools and site location.

    PubMed

    Greenslade, Penelope; Florentine, Singarayer K; Hansen, Brigita D; Gell, Peter A

    2016-08-01

    Monitoring forms the basis for understanding ecological change. It relies on repeatability of methods to ensure detected changes accurately reflect the effect of environmental drivers. However, operator bias can influence the repeatability of field and laboratory work. We tested this for invertebrates and diatoms in three trials: (1) two operators swept invertebrates from heath vegetation, (2) four operators picked invertebrates from pyrethrum knockdown samples from tree trunk and (3) diatom identifications by eight operators in three laboratories. In each trial, operators were working simultaneously and their training in the field and laboratory was identical. No variation in catch efficiency was found between the two operators of differing experience using a random number of net sweeps to catch invertebrates when sequence, location and size of sweeps were random. Number of individuals and higher taxa collected by four operators from tree trunks varied significantly between operators and with their 'experience ranking'. Diatom identifications made by eight operators were clustered together according to which of three laboratories they belonged. These three tests demonstrated significant potential bias of operators in both field and laboratory. This is the first documented case demonstrating the significant influence of observer bias on results from invertebrate field-based studies. Examples of two long-term trials are also given that illustrate further operator bias. Our results suggest that long-term ecological studies using invertebrates need to be rigorously audited to ensure that operator bias is accounted for during analysis and interpretation. Further, taxonomic harmonisation remains an important step in merging field and laboratory data collected by different operators.

  4. Neutron Detector Gamma Insensitivity Criteria

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Stephens, Daniel L.

    2009-10-21

    The shortage of 3He has triggered the search for an effective alternative neutron detection technology for radiation portal monitor applications. Any new detection technology must satisfy two basic criteria: 1) it must meet the neutron detection efficiency requirement, and 2) it must be insensitive to gamma ray interference at a prescribed level, while still meeting the neutron detection requirement. It is the purpose of this document to define this latter criterion.

  5. Impact of the Revised 10 CFR 835 on the Neutron Dose Rates at LLNL

    SciTech Connect

    Radev, R

    2009-01-13

    In June 2007, 10 CFR 835 [1] was revised to include new radiation weighting factors for neutrons, updated dosimetric models, and dose terms consistent with the newer ICRP recommendations. A significant aspect of the revised 10 CFR 835 is the adoption of the recommendations outlined in ICRP-60 [2]. The recommended new quantities demand a review of much of the basic data used in protection against exposure to sources of ionizing radiation. The International Commission on Radiation Units and Measurements has defined a number of quantities for use in personnel and area monitoring [3,4,5] including the ambient dose equivalent H*(d) to be used for area monitoring and instrument calibrations. These quantities are used in ICRP-60 and ICRP-74. This report deals only with the changes in the ambient dose equivalent and ambient dose rate equivalent for neutrons as a result of the implementation of the revised 10 CFR 835. In the report, the terms neutron dose and neutron dose rate will be used for convenience for ambient neutron dose and ambient neutron dose rate unless otherwise stated. This report provides a qualitative and quantitative estimate of how much the neutron dose rates at LLNL will change with the implementation of the revised 10 CFR 835. Neutron spectra and dose rates from selected locations at the LLNL were measured with a high resolution spectroscopic neutron dose rate system (ROSPEC) as well as with a standard neutron rem meter (a.k.a., a remball). The spectra obtained at these locations compare well with the spectra from the Radiation Calibration Laboratory's (RCL) bare californium source that is currently used to calibrate neutron dose rate instruments. The measurements obtained from the high resolution neutron spectrometer and dose meter ROSPEC and the NRD dose meter compare within the range of {+-}25%. When the new radiation weighting factors are adopted with the implementation of the revised 10 CFR 835, the measured dose rates will increase by up to 22

  6. Results of 1999 Spectral Gamma-Ray and Neutron Moisture Monitoring of Boreholes at Specific Retention Facilities in the 200 East Area, Hanford Site

    SciTech Connect

    DG Horton; RR Randall

    2000-01-18

    Twenty-eight wells and boreholes in the 200 East Are% Hanford Site, Washington were monitored in 1999. The monitored facilities were past-practice liquid waste disposal facilities and consisted of six cribs and nineteen ''specific retention'' cribs and trenches. Monitoring consisted of spectral gamma-ray and neutron moisture logging. All data are included in Appendix B. The isotopes {sup 137}Cs, {sup 60}Co, {sup 235}U, {sup 238}U, and {sup 154}Eu were identified on spectral gamma logs from boreholes monitoring the PUREX specific retention facilities; the isotopes {sup 137}Cs, {sup 60}Co, {sup 125}Sb, and {sup 154}Eu were identified on the logs from boreholes at the BC Controlled Area cribs and trenches; and {sup 137}Cs, {sup 60}Co, and {sup 125}Sb were, identified on the logs from boreholes at the BX specific retention trenches. Three boreholes in the BC Controlled Area and one at the BX trenches had previous spectral gamma logs available for comparison with 1999 logs. Two of those logs showed that changes in the subsurface distribution of {sup 137}CS and/or {sup 60}Co had occurred since 1992. Although the changes are not great, they do point to continued movement of contaminants in the vadose zone. The logs obtained in 1999 create a larger baseline for comparison with future logs. Numerous historical gross gamma logs exist from most of the boreholes logged. Qualitative comparison of those logs with the 1999 logs show many substantial changes, most of which reflect the decay of deeper short-lived isotopes, such as {sup 106}Ru and {sup 125}Sb, and the much slower decay of shallower and longer-lived isotopes such as {sup 137}Cs. The radionuclides {sup 137}Cs and {sup 60}Co have moved in two boreholes since 1992. Given the amount of movement and the half-lives of the isotopes, it is expected that they will decay to insignificant amounts before reaching groundwater. However, gamma ray logging cannot detect many of the contaminants of interest such as {sup 99}Tc, NO

  7. Neutron beam imaging at neutron spectrometers at Dhruva

    SciTech Connect

    Desai, Shraddha S.; Rao, Mala N.

    2012-06-05

    A low efficiency, 2-Dimensional Position Sensitive Neutron Detector based on delay line position encoding is developed. It is designed to handle beam flux of 10{sup 6}-10{sup 7} n/cm{sup 2}/s and for monitoring intensity profiles of neutron beams. The present detector can be mounted in transmission mode, as the hardware allows maximum neutron transmission in sensitive region. Position resolution of 1.2 mm in X and Y directions, is obtained. Online monitoring of beam images and intensity profile of various neutron scattering spectrometers at Dhruva are presented. It shows better dynamic range of intensity over commercial neutron camera and is also time effective over the traditionally used photographic method.

  8. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  9. Personnel Retention Model Analysis.

    DTIC Science & Technology

    1980-01-01

    Of01 owee)V fOT public ,ei~ rd a;It _Ltributo su~ntd 11T. mgvOUTMu STATEMET (W10 sme inO" spr on.6 as. MI Afra Sme Bw Active Arumy. Personnel...S30. 1 * *0 .(4 s 5 *a j* IJ’) 531: IFR (JJFK)LTR(jjR ) GC To e02 532: RS ( ji j,,GF , 31 1 * SIJ’@jk K 533: *(J J F, )- K 534: 602 IF(ARS5J4

  10. Neutron dosimetry

    DOEpatents

    Quinby, Thomas C.

    1976-07-27

    A method of measuring neutron radiation within a nuclear reactor is provided. A sintered oxide wire is disposed within the reactor and exposed to neutron radiation. The induced radioactivity is measured to provide an indication of the neutron energy and flux within the reactor.

  11. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  12. Pocket neutron REM meter

    SciTech Connect

    Quam, W.; Del Duca, T.; Plake, W.; Graves, G.; DeVore, T.; Warren, J.

    1982-01-01

    This paper describes a pocket-calculator-sized, neutron-sensitive, REM-responding personnel dosimeter that uses three tissue-equivalent cylindrical proportional counters as neutron-sensitive detectors. These are conventionally called Linear Energy Transfer (LET) counters. Miniaturized hybrid circuits are used for the linear pulse handling electronics, followed by a 256-channel ADC. A CMOS microprocessor is used to calculate REM exposure from the basic rads-tissue data supplied by the LET counters and also to provide timing and display functions. The instrument is used to continuously accumulate time in hours since reset, total counts accumulated, rads-tissue, and REM. At any time the user can display any one of these items or a channel number (an aid in calibration). The instrument provides such data with a precision of +- 3% for a total exposure of 1 mREM over 8 hours.

  13. Pocket neutron REM meter

    SciTech Connect

    Quam, W.; Del Duca, T.; Plake, W.; Graves, G.; DeVore, T.; Warren, J.

    1982-01-01

    This paper describes a pocket-calculator-sized, neutron-sensitive, REM-responding personnel dosimeter that uses three tissue-equivalent cylindrical proportional counters as neutron-sensitive detectors. These are conventionally called Linear Energy Transfer (LET) counters. Miniaturized hybrid circuits are used for the linear pulse handling electronics, followed by a 256-channel ADC. A CMOS microprocessor is used to calculate REM exposure from the basic rads-tissue data supplied by the LET counters and also to provide timing and display functions. The instrument is used to continuously accumulate time in hours since reset, total counts accumulated, rads-tissue, and REM. The user can display any one of these items or a channel number (an aid in calibration) at any time. Such data are provided with a precision of +- 3% for a total exposure of 1 mREM over eight hours.

  14. 10 CFR 34.47 - Personnel monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... dosimeter must be sent for processing within 24 hours. In addition, the individual may not resume work... (sounds) before using at the start of each shift; (2) Be set to give an alarm signal at a preset dose...

  15. Personnel Management Institutes 1974.

    ERIC Educational Resources Information Center

    Hinman, Stanley B., Jr.

    This report is a compilation of presentations made at the Personnel Management Institutes held by the New York State School Boards Association in the fall of 1974. Included are the following six presentations: "New Laws Affecting School Boards and School Administration," by Bernard T. McGivern; "How to Prepare for Tenure Hearings,…

  16. Personnel Management in Libraries.

    ERIC Educational Resources Information Center

    Rubin, Richard, Ed.

    1989-01-01

    Twelve articles discuss personnel management in libraries. Topics covered include building job commitment among employers, collective bargaining, entry-level recruitment, employee turnover, performance evaluation, managing resistance to change, training problems, productivity, employee stress, compensation systems, and the Allerton Park Institute.…

  17. Educational Personnel Evaluation.

    ERIC Educational Resources Information Center

    Thomas, M. Donald

    1985-01-01

    In this successful 10-year-old Salt Lake City, Utah, personnel evaluation program, every employee is entitled to and guaranteed the protection of due process--shortcomings are identified, assistance provided, and peers involved in employment decisions. Employees who cannot provide satisfactory service or learn the necessary skills are dismissed.…

  18. Evaluating School Personnel Today.

    ERIC Educational Resources Information Center

    Poliakoff, Lorraine L.

    This document, an evaluation of school personnel, is based on a review of the literature on evaluation in the ERIC system. Emphasis is placed on the evaluation of school administrators, teacher evaluation by students, and the teacher's role in evaluation. A 23-item bibliography is included. (MJM)

  19. Personnel Management. Universities.

    ERIC Educational Resources Information Center

    Ohio Board of Regents, Columbus. Management Improvement Program.

    This manual is one of 10 completed in the Ohio Management Improvement Program (MIP) during the 1971-73 biennium. In this project, Ohio's 34 public universities and colleges, in an effort directed and staffed by the Ohio Board of Regents, have developed manuals of management practices, in this case, concerning personnel management. Emphasis in this…

  20. Monitoring

    SciTech Connect

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

    2004-11-23

    The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

  1. From the sprinkler to satellite: Combining fixed and mobile cosmic-ray neutron probes for realtime multiscale monitoring of soil moisture in agricultural systems

    NASA Astrophysics Data System (ADS)

    Franz, T. E.; Avery, W. A.; Finkenbiner, C. E.

    2015-12-01

    Approximately 40% of global food production comes from irrigated agriculture. With the increasing demand for food even greater pressures will be placed on water resources within these systems. In this work we aimed to characterize the spatial and temporal patterns of soil moisture at various scales by combining fixed and roving cosmic-ray neutron probes at four study sites across an East-West precipitation gradient overtopping the High Plains Aquifer (HPA). Each of the four study sites consisted of coarse scale mapping of the entire ~12 by 12 km domain and detailed mapping of 1 quarter section (0.8 by 0.8 km) agricultural field. By using a simplistic data merging technique we are able to produce a statistical daily soil moisture product at a variety of key spatial scales in support of irrigation water management technology: the individual sprinkler (~102 m2) for variable rate irrigation, the individual pie slice (~103 m2) for variable speed irrigation, and the quarter section (0.64 km2) for uniform rate irrigation. In addition, we are able to provide a daily soil moisture product over the 144 km2 study area at a variety of key remote sensing scales 1, 9, and 144 km2. These products can be used to support SMAP/SMOS through calibration, validation, and value addition by statistical downscaling. Future work could include larger scale monitoring in support of GRACE total water storage calculations in the HPA or other key groundwater resource locations by incorporating existing COSMOS sites or establishment of new networks.

  2. Workplace characterisation in mixed neutron-gamma fields, specific requirements and available methods at high-energy accelerators.

    PubMed

    Silari, Marco

    2007-01-01

    A good knowledge of the radiation field present outside the shielding of high-energy particle accelerators is very important to be able to select the type of detectors (active and/or passive) to be employed for area monitoring and the type of personal dosemeter required for estimating the doses received by individuals. Around high-energy electron and proton accelerators the radiation field is usually dominated by neutrons and photons, with minor contributions from other charged particles. Under certain circumstances, muon radiation in the forward beam direction may also be present. Neutron dosimetry and spectrometry are of primary importance to characterise the radiation field and thus to correctly evaluate personnel exposure. Starting from the beam parameters important for radiation monitoring, the paper first briefly reviews the stray radiation fields encountered around high-energy accelerators and then addresses the relevant techniques employed for their monitoring. Recent developments to increase the response of neutron measuring devices beyond 10-20 MeV are illustrated. Instruments should be correctly calibrated either in reference monoenergetic radiation fields or in a field similar to the field in which they are used (workplace calibration). The importance of the instrument calibration is discussed and available neutron calibration facilities are briefly reviewed.

  3. Californium Multiplier Part I: design for neutron radiography

    SciTech Connect

    Crosbie, K.L.; Preskitt, C.A.; John, J.; Hastings, J.D.

    1982-01-01

    The Californium Multiplier (CFX) is a subcritical assembly of enriched uranium surrounding a californium-252 neutron source. The function of the CFX is to multiply the neutrons emitted by the source to a number sufficient for neutron radiography. The CFX is designed to provide a collimated beam of thermal neutrons from which the gamma radiation is filtered, and the scattered neutrons are reduced to make it suitable for high resolution radiography. The entire system has inherent safety features, which provide for system and personnel safety, and it operates at moderate cost. In Part I, the CFX and the theory of its operation are described in detail.

  4. Neutron Transport Simulations for NIST Neutron Lifetime Experiment

    NASA Astrophysics Data System (ADS)

    Li, Fangchen; BL2 Collaboration Collaboration

    2016-09-01

    Neutrons in stable nuclei can exist forever; a free neutron lasts for about 15 minutes on average before it beta decays to a proton, an electron, and an antineutrino. Precision measurements of the neutron lifetime test the validity of weak interaction theory and provide input into the theory of the evolution of light elements in the early universe. There are two predominant ways of measuring the neutron lifetime: the bottle method and the beam method. The bottle method measures decays of ultracold neutrons that are stored in a bottle. The beam method measures decay protons in a beam of cold neutrons of known flux. An improved beam experiment is being prepared at the National Institute of Science and Technology (Gaithersburg, MD) with the goal of reducing statistical and systematic uncertainties to the level of 1 s. The purpose of my studies was to develop computer simulations of neutron transport to determine the beam collimation and study the neutron distribution's effect on systematic effects for the experiment, such as the solid angle of the neutron flux monitor. The motivation for the experiment and the results of this work will be presented. This work was supported, in part, by a Grant to Gettysburg College from the Howard Hughes Medical Institute through the Precollege and Undergraduate Science Education Program.

  5. Personnel Launch System definition

    NASA Astrophysics Data System (ADS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-10-01

    A lifting-body Personnel Launch System (PLS) is defined for assured manned access to space for future U.S. space missions. The reusable craft described is configured for reliable and safe operations, maintainability, affordability, and improved operability, and could reduce life-cycle costs associated with placing personnel into orbit. Flight simulations show the PLS to be a very flyable vehicle with very little control and propellant expenditure required during entry. The attention to crew safety has resulted in the design of a system that provides protection for the crew throughout the mission profile. However, a new operations philosophy for manned space vehicles must be adopted to fully achieve low-cost, manned earth-to-orbit transportation.

  6. Personnel Launch System definition

    NASA Technical Reports Server (NTRS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-01-01

    A lifting-body Personnel Launch System (PLS) is defined for assured manned access to space for future U.S. space missions. The reusable craft described is configured for reliable and safe operations, maintainability, affordability, and improved operability, and could reduce life-cycle costs associated with placing personnel into orbit. Flight simulations show the PLS to be a very flyable vehicle with very little control and propellant expenditure required during entry. The attention to crew safety has resulted in the design of a system that provides protection for the crew throughout the mission profile. However, a new operations philosophy for manned space vehicles must be adopted to fully achieve low-cost, manned earth-to-orbit transportation.

  7. PTSD among military personnel.

    PubMed

    Creamer, Mark; Wade, Darryl; Fletcher, Susan; Forbes, David

    2011-04-01

    Although symptoms characteristic of post-traumatic stress disorder (PTSD) have been noted in military personnel for many centuries, it was not until 1980 that the disorder was formally recognized and became the focus of legitimate study. This paper reviews our current state of knowledge regarding the prevalence and course of this complex condition in past and present members of the defence forces. Although rates vary across conflicts and countries, there is no doubt that PTSD affects substantial numbers of personnel and results in considerable impairment in functioning and quality of life. The paper goes on to discuss recent attempts to build resilience and to promote adjustment following deployment, noting that there is little evidence at this stage upon which to draw firm conclusions. Finally, effective treatment for PTSD is reviewed, with particular reference to the challenges posed by this population in a treatment setting.

  8. An Introduction to the Army Personnel System

    DTIC Science & Technology

    1992-01-01

    Tests and procedures in the personnel sys~cm 14 3. Current selection/classification process . . 15 Aocession For NTIC ’ & J U] V ~8 1A / . .. . . AN...other Armed Services. The Army, which has the largest number of pure combat jobs (i.e. jobs that do not require nor train marketable civilian skills...their recruiting tours. The recruiters are aided by a continuous campaign of advertising and market research, which has been monitored in recent years

  9. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  10. Models of Personnel Needs Assessment.

    ERIC Educational Resources Information Center

    Mattson, Beverly

    This report presents samples of models and strategies for determining professional development needs of special education personnel. The following areas are covered: definitions of needs and the needs assessment process; personnel needs assessment regulations under the Comprehensive System of Personnel Development, the Individuals with…

  11. Measuring neutron spectra in radiotherapy using the nested neutron spectrometer

    SciTech Connect

    Maglieri, Robert Evans, Michael; Seuntjens, Jan; Kildea, John; Licea, Angel

    2015-11-15

    Purpose: Out-of-field neutron doses resulting from photonuclear interactions in the head of a linear accelerator pose an iatrogenic risk to patients and an occupational risk to personnel during radiotherapy. To quantify neutron production, in-room measurements have traditionally been carried out using Bonner sphere systems (BSS) with activation foils and TLDs. In this work, a recently developed active detector, the nested neutron spectrometer (NNS), was tested in radiotherapy bunkers. Methods: The NNS is designed for easy handling and is more practical than the traditional BSS. Operated in current-mode, the problem of pulse pileup due to high dose-rates is overcome by measuring current, similar to an ionization chamber. In a bunker housing a Varian Clinac 21EX, the performance of the NNS was evaluated in terms of reproducibility, linearity, and dose-rate effects. Using a custom maximum-likelihood expectation–maximization algorithm, measured neutron spectra at various locations inside the bunker were then compared to Monte Carlo simulations of an identical setup. In terms of dose, neutron ambient dose equivalents were calculated from the measured spectra and compared to bubble detector neutron dose equivalent measurements. Results: The NNS-measured spectra for neutrons at various locations in a treatment room were found to be consistent with expectations for both relative shape and absolute magnitude. Neutron fluence-rate decreased with distance from the source and the shape of the spectrum changed from a dominant fast neutron peak near the Linac head to a dominant thermal neutron peak in the moderating conditions of the maze. Monte Carlo data and NNS-measured spectra agreed within 30% at all locations except in the maze where the deviation was a maximum of 40%. Neutron ambient dose equivalents calculated from the authors’ measured spectra were consistent (one standard deviation) with bubble detector measurements in the treatment room. Conclusions: The NNS may

  12. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Moon, S.; White, R. S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron detector and additional analysis corrections lead to slightly changed neutron fluxes. The theoretical angular distributions of Merker (1975) are in general agreement with the reported experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current is in agreement with the experimental values from 10 to 100 MeV. The experimental fluxes obtained agree with those of Kanbach et al. (1974) in the overlap region from 70 to 100 MeV.

  13. Radial Flux Distribution of Low-Energy Neutrons.

    ERIC Educational Resources Information Center

    Higinbotham, J.

    1979-01-01

    Describes an experiment designed to illustrate the basic principle involved in the process of moderation of fast neutrons by water, and the monitoring of the low-energy neutron flux using indium as a probe. (GA)

  14. Characterization of neutron calibration fields at the TINT's 50 Ci americium-241/beryllium neutron irradiator

    NASA Astrophysics Data System (ADS)

    Liamsuwan, T.; Channuie, J.; Ratanatongchai, W.

    2015-05-01

    Reliable measurement of neutron radiation is important for monitoring and protection in workplace where neutrons are present. Although Thailand has been familiar with applications of neutron sources and neutron beams for many decades, there is no calibration facility dedicated to neutron measuring devices available in the country. Recently, Thailand Institute of Nuclear Technology (TINT) has set up a multi-purpose irradiation facility equipped with a 50 Ci americium-241/beryllium neutron irradiator. The facility is planned to be used for research, nuclear analytical techniques and, among other applications, calibration of neutron measuring devices. In this work, the neutron calibration fields were investigated in terms of neutron energy spectra and dose equivalent rates using Monte Carlo simulations, an in-house developed neutron spectrometer and commercial survey meters. The characterized neutron fields can generate neutron dose equivalent rates ranging from 156 μSv/h to 3.5 mSv/h with nearly 100% of dose contributed by neutrons of energies larger than 0.01 MeV. The gamma contamination was less than 4.2-7.5% depending on the irradiation configuration. It is possible to use the described neutron fields for calibration test and routine quality assurance of neutron dose rate meters and passive dosemeters commonly used in radiation protection dosimetry.

  15. Neutron measurements of the OGO-VI Spacecraft

    NASA Technical Reports Server (NTRS)

    Lockwood, J. A.

    1973-01-01

    The neutron measurements with the OGO-6 spacecraft are reported. Topics discussed include: the design and calibration of a neutron monitor for measuring the cosmic ray neutron leakages from the earth's atmosphere, determination of latitude dependence of cosmic ray leakage flux, determination of the angular distribution of neutron leakage flux as deduced by measurements of the altitude dependence, and verification of the solar modulation of the cosmic ray source for the neutron leakage.

  16. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  17. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  18. Competent human research personnel.

    PubMed

    Arford, Patricia H; Knowles, Marilyn B; Sneed, Nancee V

    2008-12-01

    The process of conducting human research is highly regulated, rigorous, detailed oriented, potentially harmful, and, hopefully, beneficial. Health professionals learn how to critique, design, analyze, and apply human research but have minimal education in how to conduct human research. Successful completion of a 24-hour course was mandated for research support personnel to enhance the protection of human subjects, improve the integrity of data collected, and ensure cost-effective results. Routine audits demonstrated that the course substantially improved the documentation of the informed consent process, source documentation, protocol adherence, and regulatory compliance.

  19. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  20. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  1. Daily multiwavelength Swift monitoring of the neutron star low-mass X-ray binary Cen X-4: evidence for accretion and reprocessing during quiescence

    NASA Astrophysics Data System (ADS)

    Bernardini, F.; Cackett, E. M.; Brown, E. F.; D'Angelo, C.; Degenaar, N.; Miller, J. M.; Reynolds, M.; Wijnands, R.

    2013-12-01

    We conducted the first long-term (60 d), multiwavelength (optical, ultraviolet, UV, and X-ray) simultaneous monitoring of Cen X-4 with daily Swift observations from 2012 June to August, with the goal of understanding variability in the low-mass X-ray binary Cen X-4 during quiescence. We found Cen X-4 to be highly variable in all energy bands on time-scales from days to months, with the strongest quiescent variability a factor of 22 drop in the X-ray count rate in only 4 d. The X-ray, UV and optical (V band) emission are correlated on time-scales down to less than 110 s. The shape of the correlation is a power law with index γ about 0.2-0.6. The X-ray spectrum is well fitted by a hydrogen neutron star (NS) atmosphere (kT = 59-80 eV) and a power law (with spectral index Γ = 1.4-2.0), with the spectral shape remaining constant as the flux varies. Both components vary in tandem, with each responsible for about 50 per cent of the total X-ray flux, implying that they are physically linked. We conclude that the X-rays are likely generated by matter accreting down to the NS surface. Moreover, based on the short time-scale of the correlation, we also unambiguously demonstrate that the UV emission cannot be due to either thermal emission from the stream impact point, or a standard optically thick, geometrically thin disc. The spectral energy distribution shows a small UV emitting region, too hot to arise from the accretion disc, that we identified as a hotspot on the companion star. Therefore, the UV emission is most likely produced by reprocessing from the companion star, indeed the vertical size of the disc is small and can only reprocess a marginal fraction of the X-ray emission. We also found the accretion disc in quiescence to likely be UV faint, with a minimal contribution to the whole UV flux.

  2. Amorphous Silicon Based Neutron Detector

    SciTech Connect

    Xu, Liwei

    2004-12-12

    Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield using low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: · High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; · Various single-junction and double junction detector devices have been fabricated; · The detector devices fabricated have been systematically tested and analyzed. · Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies

  3. Calculations to support JET neutron yield calibration: Modelling of neutron emission from a compact DT neutron generator

    NASA Astrophysics Data System (ADS)

    Čufar, Aljaž; Batistoni, Paola; Conroy, Sean; Ghani, Zamir; Lengar, Igor; Milocco, Alberto; Packer, Lee; Pillon, Mario; Popovichev, Sergey; Snoj, Luka

    2017-03-01

    At the Joint European Torus (JET) the ex-vessel fission chambers and in-vessel activation detectors are used as the neutron production rate and neutron yield monitors respectively. In order to ensure that these detectors produce accurate measurements they need to be experimentally calibrated. A new calibration of neutron detectors to 14 MeV neutrons, resulting from deuterium-tritium (DT) plasmas, is planned at JET using a compact accelerator based neutron generator (NG) in which a D/T beam impinges on a solid target containing T/D, producing neutrons by DT fusion reactions. This paper presents the analysis that was performed to model the neutron source characteristics in terms of energy spectrum, angle-energy distribution and the effect of the neutron generator geometry. Different codes capable of simulating the accelerator based DT neutron sources are compared and sensitivities to uncertainties in the generator's internal structure analysed. The analysis was performed to support preparation to the experimental measurements performed to characterize the NG as a calibration source. Further extensive neutronics analyses, performed with this model of the NG, will be needed to support the neutron calibration experiments and take into account various differences between the calibration experiment and experiments using the plasma as a source of neutrons.

  4. 5 CFR 430.306 - Monitoring performance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors...

  5. 5 CFR 430.306 - Monitoring performance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Monitoring performance. 430.306 Section 430.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Managing Senior Executive Performance § 430.306 Monitoring performance. (a) Supervisors...

  6. Neutron-chamber detectors and applications

    SciTech Connect

    Fehlau, P.E.; Atwater, H.F.; Coop, K.L.

    1990-01-01

    Detector applications in Nuclear Safeguards and Waste Management have included measuring neutrons from fission and (alpha,n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive; can have large apertures, usually through a thin chamber wall; and offer very good detection efficiency per dollar. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources. 9 refs., 6 figs., 2 tabs.

  7. NEUTRON SOURCE

    DOEpatents

    Bernander, N.K. et al.

    1960-10-18

    An apparatus is described for producing neutrons through target bombardment with deuterons. Deuterium gas is ionized by electron bombardment and the deuteron ions are accelerated through a magnetic field to collimate them into a continuous high intensity beam. The ion beam is directed against a deuteron pervious metal target of substantially the same nnaterial throughout to embed the deuterous therein and react them to produce neutrons. A large quantity of neutrons is produced in this manner due to the increased energy and quantity of ions bombarding the target.

  8. Thermal neutron detection system

    DOEpatents

    Peurrung, Anthony J.; Stromswold, David C.

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  9. Personnel-dosimetry intercomparison studies at the Oak Ridge National Laboratory

    SciTech Connect

    Swaja, R.E.; Sims, C.S.

    1982-01-01

    Since 1974, seven annual personnel dosimetry intercomparison studies have been conducted at the Oak Ridge National Laboratory using the Health Physics Reactor. These studies have produced more than 2000 measurements by 72 participating organizations of neutron and gamma dose equivalents between 0.1 to 15.0 mSv in six mixed radiation fields. The relative performance of three basic types of personnel neutron dosimeters (nuclear emulsion film, thermoluminescent, and track-etch) and two basic types of gamma dosimeters (film and thermoluminescent) was assessed based on experimental results obtained during the seven intercomparisons.

  10. Personnel emergency carrier vehicle

    NASA Technical Reports Server (NTRS)

    Owens, Lester J. (Inventor); Fedor, Otto H. (Inventor)

    1987-01-01

    A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

  11. NEUTRONIC REACTOR

    DOEpatents

    Wade, E.J.

    1958-09-16

    This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

  12. Neutron reflectivity

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice; Menelle, Alain

    2015-10-01

    The specular neutron reflectivity is a technique enabling the measurement of neutron scattering length density profile perpendicular to the plane of a surface or an interface, and thereby the profile of chemical composition. The characteristic sizes that are probed range from around 5 Å up 5000 Å. It is a scattering technique that averages information on the entire surface and it is therefore not possible to obtain information within the plane of the interface. The specific properties of neutrons (possibility of tuning the contrast by isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) makes it particularly interesting in the fields of soft matter, biophysics and magnetic thin films. This course is a basic introduction to the technique and does not address the magnetic reflectivity. It is composed of three parts describing respectively its principle and its formalism, the experimental aspects of the method (spectrometers, samples) and two examples related to the materials for energy.

  13. NEUTRONIC REACTORS

    DOEpatents

    Wigner, E.P.

    1960-11-22

    A nuclear reactor is described wherein horizontal rods of thermal- neutron-fissionable material are disposed in a body of heavy water and extend through and are supported by spaced parallel walls of graphite.

  14. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  15. NEUTRONIC REACTOR

    DOEpatents

    Fraas, A.P.; Mills, C.B.

    1961-11-21

    A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

  16. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  17. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  18. Calibration issues for neutron diagnostics

    SciTech Connect

    Sadler, G.J.; Adams, J.M.; Barnes, C.W.

    1997-12-01

    The performance of diagnostic systems are limited by their weakest constituents, including their calibration issues. Neutron diagnostics are notorious for problems encountered while determining their absolute calibrations, due mainly to the nature of the neutron transport problem. In order to facilitate the determination of an accurate and precise calibration, the diagnostic design should be such as to minimize the scattered neutron flux. ITER will use a comprehensive set of neutron diagnostics--comprising radial and vertical neutron cameras, neutron spectrometers, a neutron activation system and internal and external fission chambers--to provide accurate measurements of fusion power and power densities as a function of time. The calibration of such an important diagnostic system merits careful consideration. Some thoughts have already been given to this subject during the conceptual design phase in relation to the time-integrated neutron activation and time-dependent neutron yield monitors. However, no overall calibration strategy has been worked out so far. This paper represents a first attempt to address this vital issue. Experience gained from present large tokamaks (JET, TFTR and JT60U) and proposals for ITER are reviewed. The need to use a 14-MeV neutron generator as opposed to radioactive sources for in-situ calibration of D-T diagnostics will be stressed. It is clear that the overall absolute determination of fusion power will have to rely on a combination of nuclear measuring techniques, for which the provision of accurate and independent calibrations will constitute an ongoing process as ITER moves from one phase of operation to the next.

  19. Neutron dosimetry in boron neutron capture therapy

    SciTech Connect

    Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

    1981-01-01

    The recent development of various borated compounds and the utilization of one of these (Na/sub 2/B/sub 12/H/sub 11/SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with /sup 10/B in boron containing cells through the /sup 10/B(n,..cap alpha..)/sup 7/Li reaction producing charged particles with a maximum range of approx. 10..mu..m in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize /sup 6/Li and /sup 10/B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the /sup 14/N(n,p)/sup 14/C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils.

  20. Readings in Professional Personnel Assessment.

    ERIC Educational Resources Information Center

    International Personnel Management Association, Washington, DC.

    Thirteen papers are presented that discuss issues in public personnel decision making, specifically in the area of personnel selection. After an introduction by James P. Springer, the following papers are presented: (1) "History of Employment Testing" (Matthew Hale); (2) "Job Families: A Review and Discussion of Their Implications for Personnel…

  1. Personnel Practices for Small Colleges.

    ERIC Educational Resources Information Center

    Bouchard, Ronald A.

    Personnel administration in higher education is the focus of this "hands-on, how-to-do-it" guide that provides fundamental materials for developing and maintaining a sound personnel program. Part One (Employment) examines government regulations, employee recruitment and selection, pre-employment inquiries and screening, post-employment process,…

  2. Physical Assault of School Personnel

    ERIC Educational Resources Information Center

    Kajs, Lawrence T.; Schumacher, Gary; Vital, Cheryl A.

    2014-01-01

    Physical assault against school personnel is a serious problem, although not highly publicized. This workplace violence can result in debilitating injury to school employees along with major monetary costs. This article looks at legal issues that address physical assault against school personnel as well as the roles professional associations have…

  3. SCOPE OF PUPIL PERSONNEL SERVICES.

    ERIC Educational Resources Information Center

    ECKERSON, LOUISE OMWAKE; SMITH, HYRUM M.

    PART I OF THIS PAMPHLET DESCRIBES THE INTERPROFESSIONAL RESEARCH COMMISSION ON PUPIL PERSONNEL SERVICES, WHICH WAS STARTED IN 1962 BY THE OFFICE OF EDUCATION AND FINANCED BY THE NATIONAL INSTITUTE OF MENTAL HEALTH FOR A 5-YEAR PROGRAM. THE REST OF THE PAMPHLET DEALS WITH STATISTICS AND SPECIFIC PUPIL PERSONNEL SERVICES. OF THE 60,000…

  4. College Student Personnel Graduate Placement

    ERIC Educational Resources Information Center

    Packwood, William

    1976-01-01

    ACPA's Commission XII surveyed 103 college student personnel training institutions regarding their graduate placement. Graduates were identified according to degree, sex, and race. Percentages of graduates placed, areas within the college student personnel field, types of institutions, and areas of the country were computed. The discussion…

  5. The Personnel Launch System

    NASA Technical Reports Server (NTRS)

    Piland, William M.; Talay, Theodore A.; Stone, Howard W.

    1990-01-01

    NASA has begun to study candidate vehicles for manned access to space in support of the Space Station or other future missions requiring on-demand transportation of people to and from earth orbit. One such system, which would be used to complement the present Shuttle or an upgraded version, is the Personnel Launch System (PLS), which is envisioned as a reusable priority vehicle to place people and small payloads into orbit using an experimental launch vehicle. The design of the PLS is based on a Space Station crew changeout requirement whereby eight passengers and two crew members are flown to the station and a like number are returned within a 72 hour mission duration. Experimental and computational aerothermodynamic heating studies have been conducted using a new two-color thermographic technique that involved coating the model with a phosphor that radiates at varying color intensities as a function of temperature when illuminated with UV light. A full-scale model, the HL-20, has been produced and will be used for man-machine research. Three launch vehicle concepts are being considered, a Titan IV, the Advanced Launch System, and a Shuttle equipped with liquid rocket boosters.

  6. A Technique For Determining Neutron Beam Fluence to 0.01% Uncertainty

    NASA Astrophysics Data System (ADS)

    Yue, A. T.; Dewey, M. S.; Gilliam, D. M.; Nico, J. S.; Fomin, N.; Greene, G. L.; Snow, W. M.; Wietfeldt, F. E.

    2014-03-01

    The achievable uncertainty in neutron lifetime measurements using the beam technique has been limited by the uncertainty in the determination of the neutron density in the decay volume. In the Sussex-ILL-NIST series of beam lifetime experiments, the density was determined with a neutron fluence monitor that detected the charged particle products from neutron absorption in a thin layer of 6Li or 10B. In each of the experiments, the absolute detection efficiency of the neutron monitor was determined from the measured density of the neutron absorber, the thermal neutron cross section for the absorbing material, and the solid angle of the charged particle detectors. The efficiency of the neutron monitor used in the most recent beam lifetime experiment has since been measured directly by operating it on a monochromatic neutron beam in which the total neutron rate is determined with a totally absorbing neutron detector. The absolute nature of this technique does not rely on any knowledge of neutron absorption cross sections or a measurement of the density of the neutron absorbing deposit. This technique has been used to measure the neutron monitor efficiency to 0.06% uncertainty. We show that a new monitor and absolute neutron detector employing the same technique would be capable of achieving determining neutron fluence to an uncertainty of 0.01%.

  7. Response function of a superheated drop neutron monitor with lead shell in the thermal to 400-MeV energy range.

    PubMed

    Itoga, Toshiro; Asano, Yoshihiro; Tanimura, Yoshihiko

    2011-07-01

    Superheated drop detectors are currently used for personal and environmental dosimetry and their characteristics such as response to neutrons and temperature dependency are well known. A new bubble counter based on the superheated drop technology has been developed by Framework Scientific. However, the response of this detector with the lead shell is not clear especially above several tens of MeV. In this study, the response has been measured with quasi-monoenergetic and monoenergetic neutron sources with and without a lead shell. The experimental results were compared with the results of the Monte Carlo calculations using the 'Event Generator Mode' in the PHITS code with the JENDL-HE/2007 data library to clarify the response of this detector with a lead shell in the entire energy range.

  8. Alternative Neutron Detection Testing Summary

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Erikson, Luke E.; Kernan, Warnick J.; Lintereur, Azaree T.; Siciliano, Edward R.; Stromswold, David C.; Woodring, Mitchell L.

    2010-04-08

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. Most currently deployed radiation portal monitors (RPMs) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large area neutron detector. This type of neutron detector is used in the TSA and other RPMs installed in international locations and in the Ludlum and Science Applications International Corporation RPMs deployed primarily for domestic applications. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated wavelength-shifting plastic fibers. Reported here is a summary of the testing carried out at Pacific Northwest National Laboratory on these technologies to date, as well as measurements on 3He tubes at various pressures. Details on these measurements are available in the referenced reports. Sponsors of these tests include the Department of Energy (DOE), Department of Homeland Security (DHS), and the Department of Defense (DoD), as well as internal Pacific Northwest National Laboratory funds.

  9. Technical aspects of boron neutron capture therapy at the BNL Medical Research Reactor

    SciTech Connect

    Holden, N.E.; Rorer, D.C.; Patti, F.J.; Liu, H.B.; Reciniello, R.; Chanana, A.D.

    1997-07-01

    The Brookhaven Medical Research Reactor, BMRR, is a 3 MW heterogeneous, tank-type, light water cooled and moderated, graphite reflected reactor, which was designed for biomedical studies. Early BNL work in Boron Neutron Capture Therapy (BNCT) used a beam of thermal neutrons for experimental treatment of brain tumors. Research elsewhere and at BNL indicated that higher energy neutrons would be required to treat deep seated brain tumors. Epithermal neutrons would be thermalized as they penetrated the brain and peak thermal neutron flux densities would occur at the depth of brain tumors. One of the two BMRR thermal port shutters was modified in 1988 to include plates of aluminum and aluminum oxide to provide an epithermal port. Lithium carbonate in polyethylene was added in 1991 around the bismuth port to reduce the neutron flux density coming from outside the port. To enhance the epithermal neutron flux density, the two vertical thimbles A-3 (core edge) and E-3 (in core) were replaced with fuel elements. There are now four fuel elements of 190 grams each and 28 fuel elements of 140 grams each for a total of 4.68 kg of {sup 235}U in the core. The authors have proposed replacing the epithermal shutter with a fission converter plate shutter. It is estimated that the new shutter would increase the epithermal neutron flux density by a factor of seven and the epithermal/fast neutron ratio by a factor of two. The modifications made to the BMRR in the past few years permit BNCT for brain tumors without the need to reflect scalp and bone flaps. Radiation workers are monitored via a TLD badge and a self-reading dosimeter during each experiment. An early concern was raised about whether workers would be subject to a significant dose rate from working with patients who have been irradiated. The gamma ray doses for the representative key personnel involved in the care of the first 12 patients receiving BNCT are listed. These workers did not receive unusually high exposures.

  10. Neutron therapy of cancer

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Nellans, H. N.; Shaw, M. J.

    1969-01-01

    Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology.

  11. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics.

    PubMed

    Cheon, MunSeong; Kim, Junghee

    2015-08-01

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  12. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    NASA Astrophysics Data System (ADS)

    Cheon, MunSeong; Kim, Junghee

    2015-08-01

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  13. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    SciTech Connect

    Cheon, MunSeong Kim, Junghee

    2015-08-15

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  14. NEUTRONIC REACTOR

    DOEpatents

    Hurwitz, H. Jr.; Brooks, H.; Mannal, C.; Payne, J.H.; Luebke, E.A.

    1959-03-24

    A reactor of the heterogeneous, liquid cooled type is described. This reactor is comprised of a central region of a plurality of vertically disposed elongated tubes surrounded by a region of moderator material. The central region is comprised of a central core surrounded by a reflector region which is surrounded by a fast neutron absorber region, which in turn is surrounded by a slow neutron absorber region. Liquid sodium is used as the primary coolant and circulates through the core which contains the fuel elements. Control of the reactor is accomplished by varying the ability of the reflector region to reflect neutrons back into the core of the reactor. For this purpose the reflector is comprised of moderator and control elements having varying effects on reactivity, the control elements being arranged and actuated by groups to give regulation, shim, and safety control.

  15. FAST NEUTRON SPECTROMETER

    DOEpatents

    Davis, F.J.; Hurst, G.S.; Reinhardt, P.W.

    1959-08-18

    An improved proton recoil spectrometer for determining the energy spectrum of a fast neutron beam is described. Instead of discriminating against and thereby"throwing away" the many recoil protons other than those traveling parallel to the neutron beam axis as do conventional spectrometers, this device utilizes protons scattered over a very wide solid angle. An ovoidal gas-filled recoil chamber is coated on the inside with a scintillator. The ovoidal shape of the sensitive portion of the wall defining the chamber conforms to the envelope of the range of the proton recoils from the radiator disposed within the chamber. A photomultiplier monitors the output of the scintillator, and a counter counts the pulses caused by protons of energy just sufficient to reach the scintillator.

  16. Improving neutron dosimetry using bubble detector technology

    SciTech Connect

    Buckner, M.A.

    1993-02-01

    Providing accurate neutron dosimetry for a variety of neutron energy spectra is a formidable task for any dosimetry system. Unless something is known about the neutron spectrum prior to processing the dosimeter, the calculated dose may vary greatly from that actually encountered; that is until now. The entrance of bubble detector technology into the field of neutron dosimetry has eliminated the necessity of having an a priori knowledge of the neutron energy spectra. Recently, a new approach in measuring personnel neutron dose equivalent was developed at Oak Ridge National Laboratory. By using bubble detectors in combination with current thermoluminescent dosimeters (TLDs) as a Combination Personnel Neutron Dosimeter (CPND), not only is it possible to provide accurate dose equivalent results, but a simple four-interval neutron energy spectrum is obtained as well. The components of the CPND are a Harshaw albedo TLD and two bubble detectors with theoretical energy thresholds of 100 key and 1500 keV. Presented are (1) a synoptic history surrounding emergence of bubble detector technology, (2) a brief overview of the current theory on mechanisms of interaction, (3) the data and analysis process involved in refining the response functions, (4) performance evaluation of the original CPND and a reevaluation of the same data under the modified method, (5) the procedure used to determine the reference values of component fluence and dose equivalent for field assessment, (6) analysis of the after-modification results, (7) a critique of some currently held assumptions, offering some alternative explanations, and (8) thoughts concerning potential applications and directions for future research.

  17. Nine-year evaluation of emergency department personnel exposure to ionizing radiation

    SciTech Connect

    Grazer, R.E.; Meislin, H.W.; Westerman, B.R.; Criss, E.A.

    1987-03-01

    Emergency department personnel experience potential occupational hazards from exposure to ionizing radiation (x-rays). To assess this risk, ionizing radiation exposure was analyzed during a nine-year period for 128 ED personnel. The group consisted of 21 physicians, 92 nurses, and 15 ancillary personnel. Exposure was measured for both penetrating and nonpenetrating radiation using standard film dosimeter badges. Film badge use compliance was 66.7% for physicians, 86.2% for nurses, and 86.7% for ancillary personnel. Penetrating radiation exposure averaged 0.12 mrem/month for physicians, 0.70 mrem/month for nurses, and 0 mrem/month for ancillary personnel, all less than the average natural background exposure. We concluded that if standard radiation precautions are taken, the occupational risk from ionizing radiation exposure to personnel in the ED is minimal, and that routine monitoring of radiation exposure of ED personnel is unnecessary.

  18. Expert systems for personnel assignment

    SciTech Connect

    Hardee, J.L.; Liepins, G.

    1986-01-01

    In order to reduce stress on assignment personnel (detailers) and ensure maximum fairness and consistency in the Navy's personnel assignment process, The Navy Military Personnel Command (NMPC) has begun to explore the potential use of expert systems to supplement current manual and computerized distribution methods. The Detailer's Assistant expert system is being developed to improve the detailers' ability to satisfy the needs of their constituents and Navy management. An initial prototype of the Detailer's Assistant is now being evaluated. Numerous upgrades and extensions should lead to an operational system in the near future. Further development to a production system will involve additional research in machine learning, intelligent database methods, and cooperating expert systems.

  19. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Szilard, L.

    1957-09-24

    Reactors of the type employing plates of natural uranium in a moderator are discussed wherein the plates are um-formly disposed in parallel relationship to each other thereby separating the moderator material into distinct and individual layers. Each plate has an uninterrupted sunface area substantially equal to the cross-sectional area of the active portion of the reactor, the particular size of the plates and the volume ratio of moderator to uranium required to sustain a chain reaction being determinable from the known purity of these materials and other characteristics such as the predictable neutron losses due to the formation of radioactive elements of extremely high neutron capture cross section.

  20. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  1. TRANSP modelling of total and local neutron emission on MAST

    NASA Astrophysics Data System (ADS)

    Klimek, I.; Cecconello, M.; Gorelenkova, M.; Keeling, D.; Meakins, A.; Jones, O.; Akers, R.; Lupelli, I.; Turnyanskiy, M.; Ericsson, G.; the MAST Team

    2015-02-01

    The results of TRANSP simulations of neutron count rate profiles measured by a collimated neutron flux monitor-neutron camera (NC)—for different plasma scenarios on MAST are reported. In addition, the effect of various plasma parameters on neutron emission is studied by means of TRANSP simulation. The fast ion redistribution and losses due to fishbone modes, which belong to a wider category of energetic particle modes, are observed by the NC and modelled in TRANSP.

  2. Brazilian gamma-neutron dosemeter: response to 241AmBe and 252Cf neutron sources.

    PubMed

    Souto, E B; Campos, L L

    2011-03-01

    With the aim of improving the monitoring of workers potentially exposed to neutron radiation in Brazil, the IPEN/CNEN-SP in association with PRO-RAD designed and developed a passive individual gamma-neutron mixed-field dosemeter calibrated to be used to (241)AmBe sources. To verify the dosimetry system response to different neutron spectra, prototypes were irradiated with a (252)Cf source and evaluated using the dose-calculation algorithm developed for (241)AmBe sources.

  3. Hepatitis — An Occupational Hazard in Health-Care Personnel

    PubMed Central

    Devenyi, Paul

    1973-01-01

    Viral hepatitis represents an increasing risk for health care personnel, largely due to the spread of parenteral drug abuse. While regular monitoring of high risk health care workers is a good research project, there is little evidence to show whether it is of practical value. General prophylactic and hygienic measures are still the best methods of preventing the spread of the disease. PMID:20468885

  4. A Technique for Determining Neutron Beam Fluence to 0.01% Uncertainty

    SciTech Connect

    Yue, A. T.; Dewey, M. S.; Gilliam, D. M.; Nico, J. S.; Fomin, N.; Greene, G. L.; Snow, W. M.; Wietfeldt, F. E.

    2014-01-01

    The achievable uncertainty in neutron lifetime measurements using the beam technique has been limited by the uncertainty in the determination of the neutron density in the decay volume. In the Sussex-ILL-NIST series of beam lifetime experiments, the density was determined with a neutron fluence mon itor that detected the charged particle products from neutron absorption in a thin layer of 6Li or lOB. In each of the experiments, the absolute detection efficiency of the neutron monitor was determined from the measured density of the neutron absorber, the thermal neutron cross section for the absorbing ma terial, and the solid angle of the charged particle detectors. The efficiency of the neutron monitor used in the most recent beam lifetime experiment has since been measured directly by operating it on a monochromatic neutron beam in which the total neutron rate is determined with a totally absorbing neutron detector. The absolute nature of this technique does not rely on any knowl edge of neutron absorption cross sections or a measurement of the density of the neutron absorbing deposit. This technique has been used to measure the neutron monitor efficiency to 0.06% uncertainty. VVe show that a new monitor and absolute neutron detector employing the same technique would be capable of achieving determining neutron fluence to an uncertainty of 0.01%.

  5. Health Hazards of Hospital Personnel

    PubMed Central

    Clever, Linda Hawes

    1981-01-01

    Health care workers historically have faced serious health problems, such as exposure to patients with tuberculosis. For hospital personnel today, a number of hazards exist. These range from toxic substance exposure to safety hazards presented by patients themselves. PMID:7281652

  6. Neutronic reactor

    DOEpatents

    Carleton, John T.

    1977-01-25

    A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment.

  7. NEUTRONIC REACTORS

    DOEpatents

    Anderson, H.L.

    1958-10-01

    The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

  8. Electrostatic forces for personnel restraints

    NASA Technical Reports Server (NTRS)

    Ashby, N.; Ciciora, J.; Gardner, R.; Porter, K.

    1977-01-01

    The feasibility of utilizing electrostatic forces for personnel retention devices on exterior spacecraft surfaces was analyzed. The investigation covered: (1) determination of the state of the art; (2) analysis of potential adhesion surfaces; (3) safety considerations for personnel; (4) electromagnetic force field determination and its effect on spacecraft instrumentation; and (5) proposed advances to current technology based on documentation review, analyses, and experimental test data.

  9. [Morbidity in draft military personnel].

    PubMed

    Mukhametzhanov, A M; Smagulov, N K

    2015-01-01

    Military service activity appeared to influence health state of military personnel. Body strain at initial stages of the service, connected with stress situation, affects general body resistance and manifests in higher general morbidity level with transitory disablement that decreases with adaptation. Based on normalized intensity parameters, the equation enables to ease a procedure of evaluation and forecast of transitory disablement morbidity in draft military personnel.

  10. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  11. Prediction analysis of dose equivalent responses of neutron dosemeters used at a MOX fuel facility.

    PubMed

    Tsujimura, N; Yoshida, T; Takada, C

    2011-07-01

    To predict how accurately neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the dose equivalent responses of neutron dosemeters were calculated by the spectral folding method. The dosemeters selected included two types of personal dosemeter, namely a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter, three moderator-based neutron survey meters, and one special instrument called an H(p)(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variations observed in neutron fields at workplaces.

  12. The mouse splenocyte assay, an in vivo/in vitro system for biological monitoring: studies with X-rays, fission neutrons and bleomycin.

    PubMed

    Darroudi, F; Farooqi, Z; Benova, D; Natarajan, A T

    1992-12-01

    A modified mouse splenocyte culture system was standardized after testing different mitogens (i.e., phytohemagglutinin (PHA), concanavalin A (Con A)). The mitotic index was determined for comparison between different mitogens. Following selection of appropriate mitogen (PHA 16, Flow), a series of experiments were conducted to evaluate the application of a cytokinesis-block for scoring micronuclei and assays for chromosomal aberrations produced by treatment in G0 and G2 for the purposes of biological dosimetry following in vivo and/or in vitro exposure to X-rays, fission neutrons and bleomycin. In the X-irradiation studies, the frequencies of micronuclei and chromosomal aberrations (i.e., dicentrics and rings) increased in a dose-dependent manner. These data could be fitted to a linear-quadratic model. No difference was observed between irradiation in vivo and in vitro, suggesting that measurement of dicentrics and micronuclei in vitro after X-irradiation can be used as an in vivo dosimeter. Following in vivo irradiation with 1 MeV fission neutrons and in vitro culturing of mouse splenocytes, linear dose-response curves were obtained for induction of micronuclei and chromosomal aberrations. The lethal effects of neutrons were shown to be significantly greater than for a similar dose of X-rays. The relative biological effectiveness (RBE) was 6-8 in a dose range of 0.25-3 Gy for radiation-induced asymmetrical exchanges (dicentrics and rings), and about 8 for micronuclei in a dose range of 0.25-2 Gy. Furthermore, the induction of chromosomal aberrations by bleomycin was investigated in mouse G0 splenocytes (in vitro) and compared with X-ray data. Following bleomycin treatment (2 h) a similar pattern of dose-response curve was obtained as with X-rays. In this context a bleomycin rad equivalent of 20 micrograms/ml = 0.50 Gy was estimated.

  13. Recent Advances in Neutron Physics

    ERIC Educational Resources Information Center

    Feshbach, Herman; Sheldon, Eric

    1977-01-01

    Discusses new studies in neutron physics within the last decade, such as ultracold neutrons, neutron bottles, resonance behavior, subthreshold fission, doubly radiative capture, and neutron stars. (MLH)

  14. Neutron reflecting supermirror structure

    DOEpatents

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  15. Neutron reflecting supermirror structure

    DOEpatents

    Wood, J.L.

    1992-12-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  16. BF3 Neutron Detector Tests

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.; Woodring, Mitchell L.

    2009-12-09

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world; thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and detection capabilities are being investigated. Reported here are the results of tests of the efficiency of BF3 tubes at a pressure of 800 torr. These measurements were made partially to validate models of the RPM system that have been modified to simulate the performance of BF3-filled tubes. While BF3 could be a potential replacement for 3He, there are limitations to its use in deployed systems.

  17. Advanced Neutron Spectrometer

    NASA Technical Reports Server (NTRS)

    Christl, Mark; Dobson, Chris; Norwood, Joseph; Kayatin, Matthew; Apple, Jeff; Gibson, Brian; Dietz, Kurt; Benson, Carl; Smith, Dennis; Howard, David; Rodriquez, Miguel; Watts, John; Sabra, Mohammed; Kuznetsov, Evgeny

    2013-01-01

    Energetic neutron measurements remain a challenge for space science investigations and radiation monitoring for human exploration beyond LEO. We are investigating a new composite scintillator design that uses Li6 glass scintillator embedded in a PVT block. A comparison between Li6 and Boron 10 loaded scintillators are being studied to assess the advantages and shortcomings of these two techniques. We present the details of the new Li6 design and results from the comparison of the B10 and Li6 techniques during exposures in a mixed radiation field produced by high energy protons interacting in a target material.

  18. Improved Determination of the Neutron Lifetime

    NASA Astrophysics Data System (ADS)

    Yue, A.

    2013-10-01

    The most precise determination of the neutron lifetime using the beam method reported a result of τn = (886 . 3 +/- 3 . 4) s. The dominant uncertainties were attributed to the absolute determination of the fluence of the neutron beam (2.7 s). The fluence was determined with a monitor that counted the neutron-induced charged particles from absorption in a thin, well-characterized 6Li deposit. The detection efficiency of the monitor was calculated from the areal density of the deposit, the detector solid angle, and the ENDF/B-VI 6Li(n,t)4He thermal neutron cross section. We have used a second, totally-absorbing neutron detector to directly measure the detection efficiency of the monitor on a monochromatic neutron beam of precisely known wavelength. This method does not rely on the 6Li(n,t)4He cross section or any other nuclear data. The monitor detection efficiency was measured to an uncertainty of 0.06%, which represents a five-fold improvement in uncertainty. We have verified the temporal stability of the monitor with ancillary measurements, and the measured neutron monitor efficiency has been used to improve the fluence determination in the past lifetime experiment. An updated neutron lifetime based on the improved fluence determination will be presented. Work done in collaboration with M. Dewey, D. Gilliam, J. Nico, National Institute of Standards and Technology; G. Greene, University of Tennessee / Oak Ridge National Laboratory; A. Laptev, Los Alamos National Laboratory; W. Snow, Indiana University; and F. Wietfeldt, Tulane University.

  19. Studies on the properties of an epithermal-neutron hydrogen analyzer.

    PubMed

    Papp, A; Csikai, J

    2010-09-01

    Systematic investigations have proved the advantages of the Epithermal Neutron Analyzer (ETNA) for bulk hydrogen analysis as compared to the thermal neutron techniques. Results can contribute, for example, to the design and construction of instruments needed for the detection and identification of plastic anti-personnel landmines, explosives hidden in airline baggage and cargo containers via hydrogen contents as an indicator of their presence.

  20. Lithium Loaded Glass Fiber Neutron Detector Tests

    SciTech Connect

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

    2009-11-12

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. Reported here are the results of tests of the lithium-loaded glass fibers option. This testing measured the neutron detection efficiency and gamma ray rejection capabilities of a small system manufactured by Nucsafe (Oak Ridge, TN).

  1. 48 CFR 752.7007 - Personnel compensation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  2. 48 CFR 752.7007 - Personnel compensation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  3. 48 CFR 752.7007 - Personnel compensation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  4. 48 CFR 752.7007 - Personnel compensation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  5. 48 CFR 752.7007 - Personnel compensation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  6. 21 CFR 606.20 - Personnel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Personnel. 606.20 Section 606.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS CURRENT GOOD MANUFACTURING PRACTICE FOR BLOOD AND BLOOD COMPONENTS Organization and Personnel § 606.20 Personnel. (a) (b) The personnel responsible for...

  7. 76 FR 81359 - National Security Personnel System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ... MANAGEMENT 5 CFR Chapter XCIX RIN 3206-AM 53 National Security Personnel System AGENCY: Department of Defense... Defense and Office of Personnel Management regulations concerning the National Security Personnel System... the Department of Defense (DOD) authority to establish a National Security Personnel System (NSPS)...

  8. 21 CFR 21.32 - Personnel records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... consult system notices applicable to the agency's personnel records that are published by the Office of... the procedures in § 21.33 and subparts D through F of this part, govern systems of personnel records... Personnel Management, i.e., systems that: (i) The Office of Personnel Management maintains. (ii)...

  9. 5 CFR 430.207 - Monitoring performance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Monitoring performance. 430.207 Section 430.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal for General Schedule, Prevailing Rate, and Certain Other Employees §...

  10. 5 CFR 430.207 - Monitoring performance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Monitoring performance. 430.207 Section 430.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal for General Schedule, Prevailing Rate, and Certain Other Employees §...

  11. NEUTRONIC REACTORS

    DOEpatents

    Vernon, H.C.

    1959-01-13

    A neutronic reactor of the heterogeneous, fluid cooled tvpe is described. The reactor is comprised of a pressure vessel containing the moderator and a plurality of vertically disposed channels extending in spaced relationship through the moderator. Fissionable fuel material is placed within the channels in spaced relationship thereto to permit circulation of the coolant fluid. Separate means are provided for cooling the moderator and for circulating a fluid coolant thru the channel elements to cool the fuel material.

  12. Neutron detectors at IPNS

    SciTech Connect

    Crawford, R.K.; Haumann, J.R.; Ostrowski, G.E.

    1990-01-01

    The heart of each time-of-flight neutron scattering instrument is its complement of detectors and the associated encoding and counting electronics. Currently there are ten fully-scheduled neutron scattering instruments in operation at IPNS, with three more instruments under development. Six of these instruments use position-sensitive neutron detectors (PSDs) of various types. These PSDs include a 30 cm {times} 30 cm, {approximately}3 mm resolution, neutron Anger camera area PSD with {sup 6}Li-glass scintillator; a 2.5 cm dia, {approximately}0.7 mm resolution, microchannel-plate area PSD with {sup 6}Li-glass scintillator; a 20 cm {times} 20 cm, {approximately}5 mm resolution, {sup 3}He proportional counter area PSD; a 40 cm {times} 40 cm, {approximately}4 mm resolution, {sup 3}He proportional counter area PSD; a flat 25 cm long, {approximately}1.6 mm resolution, {sup 3}He proportional counter linear PSD; and 160 cylindrical {sup 3}He proportional counter linear PSDs, each of which is 1.27 cm in dia and 60 cm long and has {approximately}14 mm resolution. In addition to these PSDs, {approximately}750 standard cylindrical {sup 3}He proportional counters of various sizes are utilized on IPNS instruments, and {approximately}20 BF{sub 3} pulsed ion chambers are in use as beam monitors. This paper discusses these various detectors and associated electronics, with emphasis on the instrumental specifications and the reasons for the selection of the different types of detectors. Observed performance of these detectors is also discussed. 19 refs., 5 figs., 2 tabs.

  13. Method for measuring dose-equivalent in a neutron flux with an unknown energy spectra and means for carrying out that method

    DOEpatents

    Distenfeld, Carl H.

    1978-01-01

    A method for measuring the dose-equivalent for exposure to an unknown and/or time varing neutron flux which comprises simultaneously exposing a plurality of neutron detecting elements of different types to a neutron flux and combining the measured responses of the various detecting elements by means of a function, whose value is an approximate measure of the dose-equivalent, which is substantially independent of the energy spectra of the flux. Also, a personnel neutron dosimeter, which is useful in carrying out the above method, comprising a plurality of various neutron detecting elements in a single housing suitable for personnel to wear while working in a radiation area.

  14. The Comprehensive, Powerful, Academic Database (CPAD): An Evaluative Study of a Predictive Tool Designed for Elementary School Personnel in Identifying At-Risk Students through Progress, Curriculum, and Performance Monitoring

    ERIC Educational Resources Information Center

    Chavez-Gibson, Sarah

    2013-01-01

    The purpose of this study is to exam in-depth, the Comprehensive, Powerful, Academic Database (CPAD), a data decision-making tool that determines and identifies students at-risk of dropping out of school, and how the CPAD assists administrators and teachers at an elementary campus to monitor progress, curriculum, and performance to improve student…

  15. The status of the Delft University Neutron Backscatter Landmine Detector (DUNBLAD).

    PubMed

    Bom, V R; Datema, C P; van Eijk, C W E

    2004-07-01

    The neutron backscattering technique may be applied to search for non-metallic landmines in relatively dry soils. A detector system using this technique has been constructed. Tests showed that anti-tank mines can reliably be found, but that, depending on the circumstances, anti-personnel mines may escape detection. A first test with a pulsed neutron generator shows that further improvements can be achieved by applying a window on the neutron transit time.

  16. Solid state neutron dosimeter for space applications

    NASA Technical Reports Server (NTRS)

    Entine, Gerald; Nagargar, Vivek; Sharif, Daud

    1990-01-01

    Personnel engaged in space flight are exposed to significant flux of high energy neutrons arising from both primary and secondary sources of ionizing radiation. Presently, there exist no compact neutron sensor capable of being integrated in a flight instrument to provide real time measurement of this radiation flux. A proposal was made to construct such an instrument using special PIN silicon diode which has the property of being insensitive to the other forms of ionizing radiation. Studies were performed to determine the design and construction of a better reading system to allow the PIN diode to be read with high precision. The physics of the device was studied, especially with respect to those factors which affect the sensitivity and reproducibility of the neutron response. This information was then used to develop methods to achieve high sensitivity at low neutron doses. The feasibility was shown of enhancing the PIN diode sensitivity to make possible the measurement of the low doses of neutrons encountered in space flights. The new PIN diode will make possible the development of a very compact, accurate, personal neutron dosimeter.

  17. Detection of buried explosives using portable neutron sources with nanosecond timing.

    PubMed

    Kuznetsov, A V; Evsenin, A V; Gorshkov, I Yu; Osetrov, O I; Vakhtin, D N

    2004-07-01

    Significant reduction of time needed to identify hidden explosives and other hazardous materials by the "neutron in, gamma out" method has been achieved by introducing timed (nanosecond) neutron sources-the so-called nanosecond neutron analysis technique. Prototype mobile device for explosives' detection based on a timed (nanosecond) isotopic (252)Cf neutron source has been created. The prototype is capable of identifying 400 g of hidden explosives in 10 min. Tests have been also made with a prototype device using timed (nanosecond) neutron source based on a portable D-T neutron generator with built-in segmented detector of accompanying alpha-particles. The presently achieved intensity of the neutron generator is 5x10(7)n/s into 4pi, with over 10(6) of these neutrons being correlated with alpha-particles detected by the built-in alpha-particle detector. Results of measurements with an anti-personnel landmine imitator are presented.

  18. High energy neutron radiography

    SciTech Connect

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

    1996-06-01

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

  19. Radiation dose to personnel during percutaneous renal calculus removal

    SciTech Connect

    Bush, W.H.; Jones, D.; Brannen, G.E.

    1985-12-01

    Radiation dose to the radiologist and other personnel was measured during 102 procedures for percutaneous removal of renal calculi from the upper collecting system. A mobile C-arm image intensifier was used to guide entrance to the kidney and stone removal. Average fluoroscopy time was 25 min. Exposure to personnel was monitored by quartz-fiber dosimeters at the collar level above the lead apron. Average radiation dose to the radiologist was 10 mrem (0.10 mSv) per case; to the surgical nurse, 4 mrem (0.04 mSv) per case; to the radiologic technologist, 4 mrem (0.04 mSv) per case; and to the anesthesiologist, 3 mrem (0.03 mSv) per case. Radiation dose to the uroradiologic team during percutaneous nephrostolithotomy is similar to that from other interventional fluoroscopic procedures and is within acceptable limits for both physicians and assisting personnel.

  20. New technique to improve the accuracy of albedo neutron dosimeter evaluations

    NASA Astrophysics Data System (ADS)

    Hankins, D. E.

    The calibration factor for albedo neutron dosimeters varies greatly depending upon the energy of the neutrons in the exposure. Calibration results obtained over an eight-year period at each Lawrence Livermore National Laboratory facility where neutron exposure may occur were reviewed. A stronger relationship than expected was found between the ratio of the readings of the 9-in. to 3-in. spheres and the percent thermal. Readings from personnel and albedo badges were reviewed. The readings were consistent with the use of a calibration factor for the albedo dosimeter which varies with changes in the ratio of the personnel and albedo dosimeter TLD readings.

  1. Martian Neutron Energy Spectrometer (MANES)

    NASA Technical Reports Server (NTRS)

    Maurer, R. H.; Roth, D. R.; Kinnison, J. D.; Goldsten, J. O.; Fainchtein, R.; Badhwar, G.

    2000-01-01

    High energy charged particles of extragalactic, galactic, and solar origin collide with spacecraft structures and planetary atmospheres. These primaries create a number of secondary particles inside the structures or on the surfaces of planets to produce a significant radiation environment. This radiation is a threat to long term inhabitants and travelers for interplanetary missions and produces an increased risk of carcinogenesis, central nervous system (CNS) and DNA damage. Charged particles are readily detected; but, neutrons, being electrically neutral, are much more difficult to monitor. These secondary neutrons are reported to contribute 30-60% of the dose equivalent in the Shuttle and MIR station. The Martian atmosphere has an areal density of 37 g/sq cm primarily of carbon dioxide molecules. This shallow atmosphere presents fewer mean free paths to the bombarding cosmic rays and solar particles. The secondary neutrons present at the surface of Mars will have undergone fewer generations of collisions and have higher energies than at sea level on Earth. Albedo neutrons produced by collisions with the Martian surface material will also contribute to the radiation environment. The increased threat of radiation damage to humans on Mars occurs when neutrons of higher mean energy traverse the thin, dry Martian atmosphere and encounter water in the astronaut's body. Water, being hydrogeneous, efficiently moderates the high energy neutrons thereby slowing them as they penetrate deeply into the body. Consequently, greater radiation doses can be deposited in or near critical organs such as the liver or spleen than is the case on Earth. A second significant threat is the possibility of a high energy heavy ion or neutron causing a DNA double strand break in a single strike.

  2. NEUTRON COUNTER

    DOEpatents

    Curtis, C.D.; Carlson, R.L.; Tubinis, M.P.

    1958-07-29

    An ionization chamber instrument is described for cylindrical electrodes with an ionizing gag filling the channber. The inner electrode is held in place by a hermetic insulating seal at one end of the outer electrode, the other end of the outer electrode being closed by a gas filling tube. The outer surface of the inner electrode is coated with an active material which is responsive to neutron bombardment, such as uranium235 or boron-10, to produce ionizing radiations in the gas. The transverse cross sectional area of the inner electrode is small in relation to that of the channber whereby substantially all of the radiations are directed toward the outer electrode.

  3. NEUTRON SOURCE

    DOEpatents

    Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

    1959-01-13

    A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

  4. Strategy for the absolute neutron emission measurement on ITER.

    PubMed

    Sasao, M; Bertalot, L; Ishikawa, M; Popovichev, S

    2010-10-01

    Accuracy of 10% is demanded to the absolute fusion measurement on ITER. To achieve this accuracy, a functional combination of several types of neutron measurement subsystem, cross calibration among them, and in situ calibration are needed. Neutron transport calculation shows the suitable calibration source is a DT/DD neutron generator of source strength higher than 10(10) n/s (neutron/second) for DT and 10(8) n/s for DD. It will take eight weeks at the minimum with this source to calibrate flux monitors, profile monitors, and the activation system.

  5. Source Book--Nursing Personnel.

    ERIC Educational Resources Information Center

    Spencer, William E.

    This book, organized in six chapters and a bibliography, presents historical and current statistics and references on the supply of nursing personnel within the United States. Chapter 1 includes a discussion of national estimates of the active nurse supply and the distribution of these nurses by field of practice and by academic preparation.…

  6. Occupational hazards to hospital personnel

    SciTech Connect

    Patterson, W.B.; Craven, D.E.; Schwartz, D.A.; Nardell, E.A.; Kasmer, J.; Noble, J.

    1985-05-01

    Hospital personnel are subject to various occupational hazards. Awareness of these risks, compliance with basic preventive measures, and adequate resources for interventions are essential components of an occupational health program. Physical, chemical, and radiation hazards; important infectious risks; and psychosocial problems prevalent in hospital workers are reviewed. A rational approach to managing and preventing these problems is offered. 370 references.

  7. Keratoconus in USAF Flying Personnel

    DTIC Science & Technology

    Despite the rigid screening of all categories of rated personnel for the ability to meet stringent visual standards, cases of keratoconus continue to...entity. Aspects of incidence, early diagnosis, serial progression, and treatment are discussed. Two cases of keratoconus which developed after four years

  8. Health Instruction Packages: Dental Personnel.

    ERIC Educational Resources Information Center

    Hayes, Gary E.; And Others

    Text, illustrations, and exercises are utilized in this set of four learning modules designed to instruct non-professional dental personnel in selected job-related skills. The first module, by Gary E. Hayes, describes how to locate the hinge axis point of the jaw, place and secure a bitefork, and perform a facebow transfer. The second module,…

  9. Personnel Management in Higher Education.

    ERIC Educational Resources Information Center

    Millett, John D.; And Others

    This document on personnel management in higher education contains three papers that are designed to be used as guidelines for educational administrators. The first two papers, by John D. Millett, discuss the scope and problems of higher education administration and the problems associated with collective bargaining and tenure on college campuses.…

  10. College Student Personnel Graduate Placement

    ERIC Educational Resources Information Center

    Greer, Richard M.; And Others

    1978-01-01

    This study reports results of ACPA Commission XII's survey of 101 college student personnel training institutions regarding their graduate placement. Graduates were identified according to degree, race, and sex. Percentages of graduates placed, specialty areas, types of institutions, areas of the country, and time and method of placement were…

  11. Californium Multiplier. Part I. Design for neutron radiography

    SciTech Connect

    Crosbie, K.L.; Preskitt, C.A.; John, J.; Hastings, J.D.

    1982-04-01

    The Californium Multiplier (CFX) is a subcritical assembly of enriched uranium surrounding a californium-252 neutron source. The function of the CFX is to multiply the neutrons emitted by the source to a number sufficient for neutron radiography. The CFX is designed to provide a collimated beam of thermal neutrons from which the gamma radiation is filtered, and the scattered neutrons are reduced to make it suitable for high resolution radiography. The entire system has inherent safety features, which provide for system and personnel safety, and it operates at moderate cost. In Part I, the CFX and the theory of its operation are described in detail. Part II covers the performance of the Mound Facility CFX.

  12. A Review of Mercury Exposure and Health of Dental Personnel.

    PubMed

    Nagpal, Natasha; Bettiol, Silvana S; Isham, Amy; Hoang, Ha; Crocombe, Leonard A

    2017-03-01

    Considerable effort has been made to address the issue of occupational health and environmental exposure to mercury. This review reports on the current literature of mercury exposure and health impacts on dental personnel. Citations were searched using four comprehensive electronic databases for articles published between 2002 and 2015. All original articles that evaluated an association between the use of dental amalgam and occupational mercury exposure in dental personnel were included. Fifteen publications from nine different countries met the selection criteria. The design and quality of the studies showed significant variation, particularly in the choice of biomarkers as an indicator of mercury exposure. In several countries, dental personnel had higher mercury levels in biological fluids and tissues than in control groups; some work practices increased mercury exposure but the exposure levels remained below recommended guidelines. Dental personnel reported more health conditions, often involving the central nervous system, than the control groups. Clinical symptoms reported by dental professionals may be associated with low-level, long-term exposure to occupational mercury, but may also be due to the effects of aging, occupational overuse, and stress. It is important that dental personnel, researchers, and educators continue to encourage and monitor good work practices by dental professionals.

  13. Neutron Stars

    NASA Astrophysics Data System (ADS)

    van den Heuvel, Ed

    Radio pulsars are unique laboratories for a wide range of physics and astrophysics. Understanding how they are created, how they evolve and where we find them in the Galaxy, with or without binary companions, is highly constraining of theories of stellar and binary evolution. Pulsars' relationship with a recently discovered variety of apparently different classes of neutron stars is an interesting modern astrophysical puzzle which we consider in Part I of this review. Radio pulsars are also famous for allowing us to probe the laws of nature at a fundamental level. They act as precise cosmic clocks and, when in a binary system with a companion star, provide indispensable venues for precision tests of gravity. The different applications of radio pulsars for fundamental physics will be discussed in Part II. We finish by making mention of the newly discovered class of astrophysical objects, the Fast Radio Bursts, which may or may not be related to radio pulsars or neutron stars, but which were discovered in observations of the latter.

  14. Neutron absorption cross section of uranium-236

    SciTech Connect

    Macklin, R.L.; Alexander, C.W.

    1988-11-01

    U-236 neutron absorption was measured as a function of neutron time-of-flight from 20 eV to 1 MeV. The neutron flux was monitored with a /sup 6/Li glass scintillator. Average cross sections from 3 keV to 1 MeV were derived. Estimated uncertainties were less than 5% below 600 keV and increased to 9.5% at 1 MeV. Resonance parametrization from 20 eV to a few keV remains to be done. 17 refs., 5 figs., 3 tabs.

  15. Monitoring the dynamics of miscible P3HT:PCBM blends: A quasi elastic neutron scattering study of organic photovoltaic active layers

    DOE PAGES

    Etampawala, Thusitha; Ratnaweera, Dilru; Morgan, Brian; ...

    2015-02-02

    Our work reports on the detailed molecular dynamic behavior of miscible blends of Poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and their pure counterparts by quasi-elastic neutron scattering measurements (QENS). The study provides the measure of relaxation processes on pico-to-nanosecond time scales. A single relaxation process was observed in pure P3HT and PCBM while two relaxation processes, one fast and one slow, were observed in the blends. The fast process was attributed to the dynamics of P3HT while the slow process was correlated to the dynamics of PCBM. The results show that the relaxation process is a balance betweenmore » two opposing effects: increased mobility due to thermal activation of P3HT molecules and decrease mobility due to the presence of PCBM which is correlated to the percent crystallinity of P3HT and local packing density of PCBM in the amorphous phase. The threshold for the domination of the thermally activated relaxation is between 5 and 9 vol.% of PCBM loading. Two distinct spatial dependences of the relaxation processes, in which the crossover length scale depends neither on temperature nor composition, were observed for all the samples. They were attributed to the collective motions of the hexyl side chains and the rotational motions of the C-C single bonds of the side chains. Finally, these results provide an understanding of the effects of PCBM loading and temperature on the dynamics of the polymer-fullerene blends which provides a tool to optimize the efficiency of charge carrier and exciton transport within the organic photovoltaic (OPV) active layer to improve the high performance of organic solar cells.« less

  16. Monitoring the dynamics of miscible P3HT:PCBM blends: A quasi elastic neutron scattering study of organic photovoltaic active layers

    SciTech Connect

    Etampawala, Thusitha; Ratnaweera, Dilru; Morgan, Brian; Diallo, Souleymane; Mamontov, Eugene; Dadmun, Mark

    2015-02-02

    Our work reports on the detailed molecular dynamic behavior of miscible blends of Poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and their pure counterparts by quasi-elastic neutron scattering measurements (QENS). The study provides the measure of relaxation processes on pico-to-nanosecond time scales. A single relaxation process was observed in pure P3HT and PCBM while two relaxation processes, one fast and one slow, were observed in the blends. The fast process was attributed to the dynamics of P3HT while the slow process was correlated to the dynamics of PCBM. The results show that the relaxation process is a balance between two opposing effects: increased mobility due to thermal activation of P3HT molecules and decrease mobility due to the presence of PCBM which is correlated to the percent crystallinity of P3HT and local packing density of PCBM in the amorphous phase. The threshold for the domination of the thermally activated relaxation is between 5 and 9 vol.% of PCBM loading. Two distinct spatial dependences of the relaxation processes, in which the crossover length scale depends neither on temperature nor composition, were observed for all the samples. They were attributed to the collective motions of the hexyl side chains and the rotational motions of the C-C single bonds of the side chains. Finally, these results provide an understanding of the effects of PCBM loading and temperature on the dynamics of the polymer-fullerene blends which provides a tool to optimize the efficiency of charge carrier and exciton transport within the organic photovoltaic (OPV) active layer to improve the high performance of organic solar cells.

  17. Neutron matter, symmetry energy and neutron stars

    NASA Astrophysics Data System (ADS)

    Gandolfi, S.; Steiner, A. W.

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron- rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  18. Neutron matter, symmetry energy and neutron stars

    SciTech Connect

    Stefano, Gandolfi; Steiner, Andrew W

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  19. Borner Ball Neutron Detector

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Bonner Ball Neutron Detector measures neutron radiation. Neutrons are uncharged atomic particles that have the ability to penetrate living tissues, harming human beings in space. The Bonner Ball Neutron Detector is one of three radiation experiments during Expedition Two. The others are the Phantom Torso and Dosimetric Mapping.

  20. Neutron reflecting supermirror structure

    DOEpatents

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

  1. 5 CFR 293.302 - Establishment of Official Personnel Folder.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Establishment of Official Personnel Folder. 293.302 Section 293.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Official Personnel Folder § 293.302 Establishment of Official Personnel...

  2. 5 CFR 293.302 - Establishment of Official Personnel Folder.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Establishment of Official Personnel Folder. 293.302 Section 293.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Official Personnel Folder § 293.302 Establishment of Official Personnel...

  3. 5 CFR 293.302 - Establishment of Official Personnel Folder.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Establishment of Official Personnel Folder. 293.302 Section 293.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Official Personnel Folder § 293.302 Establishment of Official Personnel...

  4. 5 CFR 293.302 - Establishment of Official Personnel Folder.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Establishment of Official Personnel Folder. 293.302 Section 293.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Official Personnel Folder § 293.302 Establishment of Official Personnel...

  5. 5 CFR 293.302 - Establishment of Official Personnel Folder.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Establishment of Official Personnel Folder. 293.302 Section 293.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Official Personnel Folder § 293.302 Establishment of Official Personnel...

  6. 40 CFR 792.29 - Personnel.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) GOOD LABORATORY PRACTICE STANDARDS Organization and Personnel § 792.29 Personnel. (a) Each individual.... (b) Each testing facility shall maintain a current summary of training and experience and...

  7. 40 CFR 792.29 - Personnel.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) GOOD LABORATORY PRACTICE STANDARDS Organization and Personnel § 792.29 Personnel. (a) Each individual.... (b) Each testing facility shall maintain a current summary of training and experience and...

  8. The Control Process In Personnel Management

    ERIC Educational Resources Information Center

    Tracy, Lane

    1976-01-01

    The concept of human resource planning in personnel administration is gradually reintroducing the need for control over personnel functions as is usually demanded of other functions such as production and finance. (Author/TA)

  9. Personnel Management: A J/A Perspective

    ERIC Educational Resources Information Center

    Tasca, A. J.

    1974-01-01

    Recently, personnel executives and their staffs are being asked to help management solve an increasing number of human resource and business problems. Personnel management must undergo some changes if it is to achieve its full potential. (Author/AJ)

  10. 33 CFR 157.154 - Assistant personnel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Crude Oil Washing (COW) System on Tank Vessels Personnel § 157.154 Assistant personnel. The owner... the Crude Oil Washing Operations and Equipment Manual approved by the Coast Guard under § 157.112...

  11. Contact dermatitis in military personnel.

    PubMed

    Dever, Tara T; Walters, Michelle; Jacob, Sharon

    2011-01-01

    Military personnel encounter the same allergens and irritants as their civilian counterparts and are just as likely to develop contact dermatitis from common exposures encountered in everyday life. In addition, they face some unique exposures that can be difficult to avoid owing to their occupational duties. Contact dermatitis can be detrimental to a military member's career if he or she is unable to perform core duties or avoid the inciting substances. An uncontrolled contact dermatitis can result in the member's being placed on limited-duty (ie, nondeployable) status, needing a job or rate change, or separation from military service. We present some common causes of contact dermatitis in military personnel worldwide and some novel sources of contact dermatitis in this population that may not be intuitive.

  12. NEUTRONIC REACTORS

    DOEpatents

    Wigner, E.P.; Young, G.J.

    1958-10-14

    A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

  13. NEUTRONIC REACTOR

    DOEpatents

    Stewart, H.B.

    1958-12-23

    A nuclear reactor of the type speclfically designed for the irradiation of materials is discussed. In this design a central cyllndrical core of moderating material ls surrounded by an active portlon comprlsed of an annular tank contalning fissionable material immersed ln a liquid moderator. The active portion ls ln turn surrounded by a reflector, and a well ls provided in the center of the core to accommodate the materlals to be irradiated. The over-all dimensions of the core ln at least one plane are equal to or greater than twice the effective slowing down length and equal to or less than twlce the effective diffuslon length for neutrons in the core materials.

  14. Personnel

    SciTech Connect

    2006-10-13

    Le président du conseil M.Doran explique la décision que le conseil du Cern vient de prendre sur la 4.étape du régime complémentaire des pensions. Le président du comité des finances le Dr.Andersen ainsi que le Prof.Connor(?) prennent aussi la parole

  15. Personnel

    ScienceCinema

    None

    2016-07-12

    Le président du conseil M.Doran explique la décision que le conseil du Cern vient de prendre sur la 4.étape du régime complémentaire des pensions. Le président du comité des finances le Dr.Andersen ainsi que le Prof.Connor(?) prennent aussi la parole

  16. 21 CFR 58.29 - Personnel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Personnel. 58.29 Section 58.29 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Organization and Personnel § 58.29 Personnel. (a) Each individual engaged...

  17. 21 CFR 58.29 - Personnel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Personnel. 58.29 Section 58.29 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Organization and Personnel § 58.29 Personnel. (a) Each individual engaged...

  18. 21 CFR 58.29 - Personnel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Personnel. 58.29 Section 58.29 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Organization and Personnel § 58.29 Personnel. (a) Each individual engaged...

  19. 21 CFR 58.29 - Personnel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Personnel. 58.29 Section 58.29 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Organization and Personnel § 58.29 Personnel. (a) Each individual engaged...

  20. 21 CFR 58.29 - Personnel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Personnel. 58.29 Section 58.29 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Organization and Personnel § 58.29 Personnel. (a) Each individual engaged...

  1. The Personnel Office and Computer Services: Tomorrow.

    ERIC Educational Resources Information Center

    Nicely, H. Phillip, Jr.

    1980-01-01

    It is suggested that the director of personnel should be making maximum use of available computer services. Four concerns of personnel directors are cited: number of government reports required, privacy and security, cost of space for personnel records and files, and the additional decision-making tools required for collective bargaining…

  2. 49 CFR 193.2711 - Personnel health.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Personnel health. 193.2711 Section 193.2711 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Personnel Qualifications and Training § 193.2711 Personnel health. Each...

  3. 49 CFR 193.2711 - Personnel health.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Personnel health. 193.2711 Section 193.2711 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Personnel Qualifications and Training § 193.2711 Personnel health. Each...

  4. 49 CFR 193.2711 - Personnel health.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Personnel health. 193.2711 Section 193.2711 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Personnel Qualifications and Training § 193.2711 Personnel health. Each...

  5. 49 CFR 193.2711 - Personnel health.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Personnel health. 193.2711 Section 193.2711 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Personnel Qualifications and Training § 193.2711 Personnel health. Each...

  6. 49 CFR 193.2711 - Personnel health.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Personnel health. 193.2711 Section 193.2711 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Personnel Qualifications and Training § 193.2711 Personnel health. Each...

  7. 21 CFR 211.28 - Personnel responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... from contamination. (b) Personnel shall practice good sanitation and health habits. (c) Only personnel... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS... instructed to report to supervisory personnel any health conditions that may have an adverse effect on...

  8. 29 CFR 1926.1431 - Hoisting personnel.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Environmental conditions. (i) Wind. When wind speed (sustained or gusts) exceeds 20 mph at the personnel platform, a qualified person must determine if, in light of the wind conditions, it is not safe to lift...) Hoisting personnel near power lines. Hoisting personnel within 20 feet of a power line that is up to 350...

  9. 29 CFR 1926.1431 - Hoisting personnel.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Environmental conditions. (i) Wind. When wind speed (sustained or gusts) exceeds 20 mph at the personnel platform, a qualified person must determine if, in light of the wind conditions, it is not safe to lift...) Hoisting personnel near power lines. Hoisting personnel within 20 feet of a power line that is up to 350...

  10. 14 CFR 145.151 - Personnel requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Personnel requirements. 145.151 Section 145.151 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES REPAIR STATIONS Personnel § 145.151 Personnel requirements....

  11. The Changing World of Personnel Management.

    ERIC Educational Resources Information Center

    Anderson, Eileen R.

    Although personnel management in the public sector has become increasingly difficult because of recent social changes, more worker and middle management involvement in decision-making processes can improve all levels of personnel management. The social changes affecting personnel management have assumed three forms: (1) the entrance into the work…

  12. Personnel real time dosimetry in interventional radiology.

    PubMed

    Servoli, L; Bissi, L; Fabiani, S; Magalotti, D; Placidi, P; Scorzoni, A; Calandra, A; Cicioni, R; Chiocchini, S; Dipilato, A C; Forini, N; Paolucci, M; Di Lorenzo, R; Cappotto, F P; Scarpignato, M; Maselli, A; Pentiricci, A

    2016-12-01

    Interventional radiology and hemodynamic procedures have rapidly grown in number in the past decade, increasing the importance of personnel dosimetry not only for patients but also for medical staff. The optimization of the absorbed dose during operations is one of the goals that fostered the development of real-time dosimetric systems. Indeed, introducing proper procedure optimization, like correlating dose rate measurements with medical staff position inside the operating room, the absorbed dose could be reduced. Real-time dose measurements would greatly facilitate this task through real-time monitoring and automatic data recording. Besides real-time dose monitoring could allow automatic data recording. In this work, we will describe the calibration and validation of a wireless real-time prototype dosimeter based on a new sensor device (CMOS imager). The validation measurement campaign in clinical conditions has demonstrated the prototype capability of measuring dose-rates with a frequency in the range of few Hz, and an uncertainty smaller than 10%.

  13. Neutron field for boron neutron capture therapy

    SciTech Connect

    Kanda, K.; Kobayashi, T.

    1986-01-01

    Recently, the development of an epithermal neutron source has been required by medical doctors for deeper neutron penetrations, which is to be used for deep tumor treatment and diagnosis of metastasis. Several attempts have already been made to realize an epithermal neutron field, such as the undermoderated neutron beam, the filtered neutron beam, and the use of a fission plate. At present, these facilities can not be used for actual therapy. For the treatment of deep tumor, another method has been also proposed in normal water in the body is replaced by heavy water to attain a deeper neutron penetration. At Kyoto University's Research Reactor Institute, almost all physics problems have been settled relative to thermal neutron capture therapy that has been used for treating brain tumors and for biological experiments on malignant melanoma. Very recently feasibility studies to use heavy water have been started both theoretically and experimentally. The calculation shows the deeper penetration of neutrons as expected. Two kinds of experiments were done by using the KUR guide tube: 1. Thermal neutron penetration measurement. 2. Heavy water uptake in vitro sample. In addition to the above experiment using heavy water, the development of a new epithermal neutron source using a large fission plate is in progress, which is part of a mockup experiment of an atomic bomb field newly estimated.

  14. Fluence and dose measurements for an accelerator neutron beam

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Byun, S. H.; McNeill, F. E.; Mothersill, C. E.; Seymour, C. B.; Prestwich, W. V.

    2007-10-01

    The 3 MV Van de Graaff accelerator at McMaster University accelerator laboratory is extended to a neutron irradiation facility for low-dose bystander effects research. A long counter and an Anderson-Braun type neutron monitor have been used as monitors for the determination of the total fluence. Activation foils were used to determine the thermal neutron fluence rate (around 106 neutrons s-1). Meanwhile, the interactions of neutrons with the monitors have been simulated using a Monte Carlo N Particle (MCNP) code. Bystander effects, i.e. damage occurring in cells that were not traversed by radiation but were in the same radiation environment, have been well observed following both alpha and gamma irradiation of many cell lines. Since neutron radiation involves mixed field (including gamma and neutron radiations), we need to differentiate the doses for the bystander effects from the two radiations. A tissue equivalent proportional counter (TEPC) filled with propane based tissue equivalent gas simulating a 2 μm diameter tissue sphere has been investigated to estimate the neutron and gamma absorbed doses. A photon dose contamination of the neutron beam is less than 3%. The axial dose distribution follows the inverse square law and lateral and vertical dose distributions are relatively uniform over the irradiation area required by the biological study.

  15. The US Department of Energy Personnel Dosimetry Evaluation and Upgrade Program

    SciTech Connect

    Faust, L.G.; Stroud, C.M.; Swinth, K.L.; Vallario, E.J.

    1987-11-01

    The US Department of Energy (DOE) Personnel Dosimetry Evaluation and Upgrade Program is designed to identify and evaluate dosimetry deficiencies and to conduct innovative research and development programs that will improve overall capabilities, thus ensuring that DOE can comply with applicable standards and regulations for dose measurement. To achieve these goals, two programs were initiated to evaluate and upgrade beta measurement and neutron dosimetry. 3 refs.

  16. Computer modeling and simulators as part of university training for NPP operating personnel

    NASA Astrophysics Data System (ADS)

    Volman, M.

    2017-01-01

    This paper considers aspects of a program for training future nuclear power plant personnel developed by the NPP Department of Ivanovo State Power Engineering University. Computer modeling is used for numerical experiments on the kinetics of nuclear reactors in Mathcad. Simulation modeling is carried out on the computer and full-scale simulator of water-cooled power reactor for the simulation of neutron-physical reactor measurements and the start-up - shutdown process.

  17. Neutron range spectrometer

    DOEpatents

    Manglos, Stephen H.

    1989-06-06

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

  18. Assessment of the roles of the Advanced Neutron Source Operators

    SciTech Connect

    Hill, W.E.; Houser, M.M.; Knee, H.E.; Spelt, P.F.

    1995-03-01

    The Advanced Neutron Source (ANS) is unique in the extent to which human factors engineering (HFE) principles are being applied at the conceptual design stage. initial HFE accomplishments include the development of an ANS HFE program plan, operating philosophy, and functional analysis. In FY 1994, HFE activities focused on the role of the ANS control room reactor operator (RO). An operator-centered control room model was used in conjunction with information gathered from existing ANS system design descriptions and other literature to define a list of RO responsibilities. From this list, a survey instrument was developed and administered to ANS design engineers, operations management personnel at Oak Ridge National Laboratory`s High Flux Isotope Reactor (HFIR), and HFIR ROs to detail the nature of the RO position. Initial results indicated that the RO will function as a high-level system supervisor with considerable monitoring, verification, and communication responsibilities. The relatively high level of control automation has resulted in a reshaping of the RO`s traditional safety and investment protection roles.

  19. Neutron streak camera

    DOEpatents

    Wang, Ching L.

    1983-09-13

    Apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon.

  20. Neutron streak camera

    DOEpatents

    Wang, C.L.

    1983-09-13

    Disclosed is an apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon. 4 figs.

  1. Neutron streak camera

    DOEpatents

    Wang, C.L.

    1981-05-14

    Apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon.

  2. Layered semiconductor neutron detectors

    DOEpatents

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  3. Organic metal neutron detector

    DOEpatents

    Butler, M.A.; Ginley, D.S.

    1984-11-21

    A device for detection of neutrons comprises: as an active neutron sensing element, a conductive organic polymer having an electrical conductivity and a cross-section for said neutrons whereby a detectable change in said conductivity is caused by impingement of said neutrons on the conductive organic polymer which is responsive to a property of said polymer which is altered by impingement of said neutrons on the polymer; and means for associating a change in said alterable property with the presence of neutrons at the location of said device.

  4. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, F. C.

    1986-01-01

    The use of nonmetallic or fabric structures for space application is considered. The following structures are suggested: (1) unpressurized space hangars; (2) extendable tunnels for soft docking; and (3) manned habitat for space stations, storage facilities, and work structures. The uses of the tunnel as a passageway: for personnel and equipment, eliminating extravehicular activity, for access to a control cabin on a space crane and between free flyers and the space station are outlined. The personnal occupied woven envelope robot (POWER) device is shown. The woven envelope (tunnel) acts as part of the boom of a crane. Potential applications of POWER are outlined. Several possible deflection mechanisms and design criteria are determined.

  5. Personnel Security Program. Change 2

    DTIC Science & Technology

    1993-07-14

    administrative action in a personnel security determination. # First Amendment (Ch 2, 7/14/93) 1-3 Jan 87# DoD 5200.2-R 1-312 National Agency Check (NAC) A... First Amendment (Ch 2, 7/14/93) 1-4 Jan 87# DoD 5200.2-R (1) The nature and seriousness of the conduct: (2) The circumstances surrounding the conduct...Acce-ioii For NTiS r(PA&J LI D ’••.:t . ,. ~ F .r...... An. .... # First Amendment (Ch 2, 7/14/93) VI-3 Jan 87# DoD5200.2-R 0 CHAPTER VII ISSUING

  6. BETA-GAMMA PERSONNEL DOSIMETER

    DOEpatents

    Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

    1961-01-17

    A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

  7. Personnel Launch System (PLS) study

    NASA Technical Reports Server (NTRS)

    Ehrlich, Carl F., Jr.

    1991-01-01

    NASA is currently studying a personnel launch system (PLS) approach to help satisfy the crew rotation requirements for the Space Station Freedom. Several concepts from low L/D capsules to lifting body vehicles are being examined in a series of studies as a potential augmentation to the Space Shuttle launch system. Rockwell International Corporation, under contract to NASA, analyzed a lifting body concept to determine whether the lifting body class of vehicles is appropriate for the PLS function. The results of the study are given.

  8. Neutronic Reactor Design to Reduce Neutron Loss

    DOEpatents

    Miles, F. T.

    1961-05-01

    A nuclear reactor construction is described in which an unmoderated layer of the fissionable material is inserted between the moderated portion of the reactor core and the core container steel wall. The wall is surrounded by successive layers of pure fertile material and moderator containing fertile material. The unmoderated layer of the fissionable material will insure that a greater portion of fast neutrons will pass through the steel wall than would thermal neutrons. Since the steel has a smaller capture cross section for the fast neutrons, greater nunnbers of neutrons will pass into the blanket, thereby increasing the over-all efficiency of the reactor. (AEC)

  9. NEUTRONIC REACTOR DESIGN TO REDUCE NEUTRON LOSS

    DOEpatents

    Mills, F.T.

    1961-05-01

    A nuclear reactor construction is described in which an unmoderated layer of the fissionable material is inserted between the moderated portion of the reactor core and the core container steel wall which is surrounded by successive layers of pure fertile material and fertile material having moderator. The unmoderated layer of the fissionable material will insure that a greater portion of fast neutrons will pass through the steel wall than would thermal neutrons. As the steel has a smaller capture cross-section for the fast neutrons, then greater numbers of the neutrons will pass into the blanket thereby increasing the over-all efficiency of the reactor.

  10. Performance study of the neutron-TPC

    NASA Astrophysics Data System (ADS)

    Huang, Meng; Li, Yulan; Niu, Libo; Deng, Zhi; Cheng, Xiaolei; He, Li; Zhang, Hongyan; Fu, Jianqiang; Yan, Yangyang; Cai, Yiming; Li, Yuanjing

    2017-02-01

    Fast neutron spectrometers will play an important role in the future of the nuclear industry and nuclear physics experiments, in tasks such as fast neutron reactor monitoring, thermo-nuclear fusion plasma diagnostics, nuclear reaction cross-section measurement, and special nuclear material detection. Recently, a new fast neutron spectrometer based on a GEM (Gas Electron Multiplier amplification)-TPC (Time Projection Chamber), named the neutron-TPC, has been under development at Tsinghua University. It is designed to have a high energy resolution, high detection efficiency, easy access to the medium material, an outstanding n/γ suppression ratio, and a wide range of applications. This paper presents the design, test, and experimental study of the neutron-TPC. Based on the experimental results, the energy resolution (FWHM) of the neutron-TPC can reach 15.7%, 10.3% and 7.0% with detection efficiency higher than 10‑5 for 1.2 MeV, 1.81 MeV and 2.5 MeV neutrons respectively. Supported by National Natural Science Foundation of China (11275109)

  11. Sensitivity Upgrades to the Idaho Accelerator Center Neutron Time of Flight Spectrometer

    SciTech Connect

    Thompson, S. J.; Kinlaw, M. T.; Harmon, J. F.; Wells, D. P.; Hunt, A. W.

    2007-10-26

    Past experiments have shown that discrimination between between fissionable and non-fissionable materials is possible using an interrogation technique that monitors for high energy prompt fission neutrons. Several recent upgrades have been made to the neutron time of flight spectrometer at the Idaho Accelerator Center with the intent of increasing neutron detection sensitivity, allowing for system use in nonproliferation and security applications.

  12. Development of a thermal neutron detector based on scintillating fibers and silicon photomultipliers

    SciTech Connect

    Barbagallo, Massimo; Greco, Giuseppe; Scire, Carlotta; Scire, Sergio; Cosentino, Luigi; Pappalardo, Alfio; Finocchiaro, Paolo; Montereali, Rosa Maria; Vincenti, Maria Aurora

    2010-09-15

    We propose a technique for thermal neutron detection, based on a {sup 6}Li converter placed in front of scintillating fibers readout by means of silicon photomultipliers. Such a technique allows building cheap and compact detectors and dosimeters, thus possibly opening new perspectives in terms of granular monitoring of neutron fluxes as well as space-resolved neutron detection.

  13. Diagnostic of fusion neutrons on JET tokamak using diamond detector

    SciTech Connect

    Nemtsev, G.; Amosov, V.; Marchenko, N.; Meshchaninov, S.; Rodionov, R.; Popovichev, S.; Collaboration: JET EFDA Conbributors

    2014-08-21

    In 2011-2012, an experimental campaign with a significant yield of fusion neutrons was carried out on the JET tokamak. During this campaign the facility was equipped with two diamond detectors based on natural and artificial CVD diamond. These detectors were designed and manufactured in State Research Center of Russian Federation TRINITI. The detectors measure the flux of fast neutrons with energies above 0.2 MeV. They have been installed in the torus hall and the distance from the center of plasma was about 3 m. For some of the JET pulses in this experiment, the neutron flux density corresponded to the operational conditions in collimator channels of ITER Vertical Neutron Camera. The main objective of diamond monitors was the measurement of total fast neutron flux at the detector location and the estimation of the JET total neutron yield. The detectors operate as threshold counters. Additionally a spectrometric measurement channel has been configured that allowed us to distinguish various energy components of the neutron spectrum. In this paper we describe the neutron signal measuring and calibration procedure of the diamond detector. Fluxes of DD and DT neutrons at the detector location were measured. It is shown that the signals of total neutron yield measured by the diamond detector correlate with signals measured by the main JET neutron diagnostic based on fission chambers with high accuracy. This experiment can be considered as a successful test of diamond detectors in ITER-like conditions.

  14. Impact of a proposed change in the maximum permissible dose limit for neutrons to radiation-protection programs at DOE facilities

    SciTech Connect

    Murphy, B.L.

    1981-09-01

    The National Council on Radiation Protection and Measurements (NCRP) has issued a statement advising that it is considering lowering the maximum permissible dose for neutrons. This action would present substantive problems to radiation protection programs at DOE facilities where a potential for neutron exposure exists. In addition to altering administrative controls, a lowering of the maximum permissible dose for neutrons will require advances in personnel neutron dosimetry systems, and neutron detection and measurement instrumentation. Improvement in the characterization of neutron fields and spectra at work locations will also be needed. DOE has initiated research and development programs in these areas. However, problems related to the control of personnel neutron exposure have yet to be resolved and investigators are encouraged to continue collaboration with both United States and international authorities.

  15. [Preventive vaccinations for medical personnel].

    PubMed

    Kerwat, Klaus; Goedecke, Marcel; Wulf, Hinnerk

    2014-05-01

    Vaccinations are among the most efficient and important preventive medical procedures. Modern vaccines are well tolerated. In Germany there are no longer laws for mandatory vaccinations, either for the general public or for medical personnel. Vaccinations are now merely "officially recommended" by the top health authorities on the basis of recommendations from the Standing Committee on Vaccinations (STIKO) of the Robert Koch Institute (RKI) according to § 20 para 3 of the Protection against Infection law (IfSG). The management of vaccine damage due to officially recommended vaccinations is guaranteed by the Federal States. Whereas vaccinations in childhood are generally considered to be a matter of course, the willingness to accept them decreases markedly with increasing age. In the medical sector vaccinations against, for example, hepatitis B are well accepted while other vaccinations against, for example, whooping cough or influenza are not considered to be so important. The fact that vaccinations, besides offering protection for the medical personnel, may also serve to protect the patients entrusted to medical care from nosocomial infections is often ignored.

  16. Neutron anatomy

    SciTech Connect

    Bacon, G.E.

    1994-12-31

    The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content - the crystals of the hexagonal hydroxyapatite - and this can readily be determined by neutron diffraction. In particular it can be measured over the volume of a piece of bone, utilizing distances ranging from 1mm to 10mm. The major practical problem is to avoid the intense incoherent scattering from the hydrogen in the accompanying collagen; this can best be achieved by heat-treatment and it is demonstrated that this does not affect the underlying apatite. These studies of bone give leading anatomical information on the life and activities of humans and animals - including, for example, the life history of the human femur, the locomotion of sheep, the fracture of the legs of racehorses and the life-styles of Neolithic tribes. We conclude that the material is placed economically in the bone to withstand the expected stresses of life and the environment. The experimental results are presented in terms of the magnitude of the 0002 apatite reflection. It so happens that for a random powder the 0002, 1121 reflections, which are neighboring lines in the powder pattern, are approximately equal in intensity. The latter reflection, being of manifold multiplicity, is scarcely affected by preferred orientation so that the numerical value of the 0002/1121 ratio serves quite accurately as a quantitative measure of the degree of orientation of the c-axes in any chosen direction for a sample of bone.

  17. Neutron irradiation control in the neutron transmutation doping process in HANARO using SPND

    SciTech Connect

    Kang, Gi-Doo; Kim, Myong-Seop

    2015-07-01

    The neutron irradiation control method by using self-powered neutron detector (SPND) is developed for the neutron transmutation doping (NTD) application in HANARO. An SPND is installed at a fixed position of the upper part of the sleeve in HANARO NTD hole for real-time monitoring of the neutron irradiation. It is confirmed that the SPND is significantly affected by the in-core condition and surroundings of the facility. Furthermore, the SPND signal changes about 15% throughout a whole cycle according to the change of the control rod position. But, it is also confirmed that the variation of the neutron flux on the silicon ingots inside the irradiation can is not so big while moving of the control rod. Accordingly, the relationship between the ratio of the neutron flux to the SPND signal output and the control rod position is established. In this procedure, the neutron flux measurement by using zirconium foil is utilized. The real NTD irradiation experiments are performed using the established relationship. The irradiated neutron fluence can be controlled within ±1.3% of the target one. The mean value of the irradiation/target ratio of the fluence is 0.9992, and the standard deviation is 0.0071. Thus, it is confirmed that the extremely accurate irradiation would be accomplished. This procedure can be useful for the SPND application installed at the fixed position to the field requiring the extremely high accuracy. (authors)

  18. Precision neutron flux measurements and applications using the Alpha Gamma device

    NASA Astrophysics Data System (ADS)

    Anderson, Eamon; Alpha Gamma; BL2 Collaboration

    2015-04-01

    The Alpha Gamma device is a totally-absorbing 10 B neutron detector designed to measure the absolute detection efficiency of a thin-film lithium neutron monitor on a monoenergetic neutron beam. The detector has been shown to measure neutron fluence with an absolute accuracy of 0.06%. This capability has been used to perform the first direct, absolute measurement of the 6Li(n , t) 4He cross section at sub-thermal energy, improve the neutron fluence determination in a past beam neutron lifetime measurement by a factor of five, and is being used to calibrate the neutron monitors for use in the upcoming beam neutron lifetime measurement BL2 (NIST Beam Lifetime 2). The principle of the measurement method will presented and the applications will be discussed. We would like to acknowledge support of this research through the NSF-PHY-1068712 grant as well as the NIST Precision Measurement Grant program.

  19. Precision neutron flux measurements and applications using the Alpha Gamma device

    NASA Astrophysics Data System (ADS)

    Anderson, Eamon

    2016-03-01

    The Alpha Gamma device is a totally-absorbing 10 B neutron detector designed to measure the absolute detection efficiency of a thin-film lithium neutron monitor on a monoenergetic neutron beam. The detector has been shown to measure neutron fluence with an absolute accuracy of 0.06%. This capability has been used to perform the first direct, absolute measurement of the 6Li(n,t) 4He cross section at sub-thermal energy, improve the neutron fluence determination in a past beam neutron lifetime measurement by a factor of five, and is being used to calibrate the neutron monitors for use in the upcoming beam neutron lifetime measurement BL2 (NIST Beam Lifetime 2). The principle of the measurement method will presented and the applications will be discussed. We would like to acknowledge support of this research through the NSF-PHY-1068712 Grant as well as the NIST Precision Measurement Grant program.

  20. Cryostat system for investigation on new neutron moderator materials at reactor TRIGA PUSPATI

    SciTech Connect

    Dris, Zakaria bin; Mohamed, Abdul Aziz bin; Hamid, Nasri A.; Azman, Azraf; Ahmad, Megat Harun Al Rashid Megat; Jamro, Rafhayudi; Yazid, Hafizal

    2016-01-22

    A simple continuous flow (SCF) cryostat was designed to investigate the neutron moderation of alumina in high temperature co-ceramic (HTCC) and polymeric materials such as Teflon under TRIGA neutron environment using a reflected neutron beam from a monochromator. Cooling of the cryostat will be carried out using liquid nitrogen. The cryostat will be built with an aluminum holder for moderator within stainless steel cylinder pipe. A copper thermocouple will be used as the temperature sensor to monitor the moderator temperature inside the cryostat holder. Initial measurements of neutron spectrum after neutron passing through the moderating materials have been carried out using a neutron spectrometer.

  1. Cryostat system for investigation on new neutron moderator materials at reactor TRIGA PUSPATI

    NASA Astrophysics Data System (ADS)

    Dris, Zakaria bin; Mohamed, Abdul Aziz bin; Hamid, Nasri A.; Azman, Azraf; Ahmad, Megat Harun Al Rashid Megat; Jamro, Rafhayudi; Yazid, Hafizal

    2016-01-01

    A simple continuous flow (SCF) cryostat was designed to investigate the neutron moderation of alumina in high temperature co-ceramic (HTCC) and polymeric materials such as Teflon under TRIGA neutron environment using a reflected neutron beam from a monochromator. Cooling of the cryostat will be carried out using liquid nitrogen. The cryostat will be built with an aluminum holder for moderator within stainless steel cylinder pipe. A copper thermocouple will be used as the temperature sensor to monitor the moderator temperature inside the cryostat holder. Initial measurements of neutron spectrum after neutron passing through the moderating materials have been carried out using a neutron spectrometer.

  2. On neutron surface waves

    SciTech Connect

    Ignatovich, V. K.

    2009-01-15

    It is shown that neutron surface waves do not exist. The difference between the neutron wave mechanics and the wave physics of electromagnetic and acoustic processes, which allows the existence of surface waves, is analyzed.

  3. Ultrafast neutron detector

    DOEpatents

    Wang, C.L.

    1985-06-19

    A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

  4. Neutron dose equivalent meter

    DOEpatents

    Olsher, Richard H.; Hsu, Hsiao-Hua; Casson, William H.; Vasilik, Dennis G.; Kleck, Jeffrey H.; Beverding, Anthony

    1996-01-01

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  5. Pulsed-neutron monochromator

    DOEpatents

    Mook, H.A. Jr.

    1984-01-01

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  6. Pulsed-neutron monochromator

    DOEpatents

    Mook, Jr., Herbert A.

    1985-01-01

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  7. Dose equivalent neutron dosimeter

    DOEpatents

    Griffith, Richard V.; Hankins, Dale E.; Tomasino, Luigi; Gomaa, Mohamed A. M.

    1983-01-01

    A neutron dosimeter is disclosed which provides a single measurements indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer containing conversion material such as .sup.6 Li and .sup.10 B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet. The density of conversion material in the radiator layer is of an amount which is chosen so that the density of tracks produced in the detecting sheet is proportional to the biological damage done by neutrons, regardless of whether the tracks are produced as the result of moderate energy neutrons striking the radiator layer or as the result of higher energy neutrons striking the sheet of track etch material.

  8. Neutron Lifetime Measurements

    NASA Astrophysics Data System (ADS)

    Nico, J. S.

    2006-11-01

    Precision measurements of neutron beta decay address basic questions in nuclear and particle physics, astrophysics, and cosmology. As the simplest semileptonic decay system, the free neutron plays an important role in understanding the physics of the weak interaction, and improving the precision of the neutron lifetime is fundamental to testing the validity of the theory. The neutron lifetime also directly affects the relative abundance of primordial helium in big bang nucleosynthesis. There are two distinct strategies for measuring the lifetime. Experiments using cold neutrons measure the absolute specific activity of a beam of neutrons by counting decay protons; experiments using confined, ultracold neutrons determine the lifetime by counting neutrons that remain after some elapsed time. The status of the recent lifetime measurements using both of these techniques is discussed.

  9. Neutron Lifetime Measurements

    SciTech Connect

    Nico, J. S.

    2006-11-17

    Precision measurements of neutron beta decay address basic questions in nuclear and particle physics, astrophysics, and cosmology. As the simplest semileptonic decay system, the free neutron plays an important role in understanding the physics of the weak interaction, and improving the precision of the neutron lifetime is fundamental to testing the validity of the theory. The neutron lifetime also directly affects the relative abundance of primordial helium in big bang nucleosynthesis. There are two distinct strategies for measuring the lifetime. Experiments using cold neutrons measure the absolute specific activity of a beam of neutrons by counting decay protons; experiments using confined, ultracold neutrons determine the lifetime by counting neutrons that remain after some elapsed time. The status of the recent lifetime measurements using both of these techniques is discussed.

  10. ULTRASONIC NEUTRON DOSIMETER

    DOEpatents

    Truell, R.; de Klerk, J.; Levy, P.W.

    1960-02-23

    A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

  11. Ion Acceleration in Solar Flares Determined by Solar Neutron Observations

    NASA Astrophysics Data System (ADS)

    Watanabe, K.; Solar Neutron Observation Group

    2013-05-01

    Large amounts of particles can be accelerated to relativistic energy in association with solar flares and/or accompanying phenomena (e.g., CME-driven shocks), and they sometimes reach very near the Earth and penetrate the Earth's atmosphere. These particles are observed by ground-based detectors (e.g., neutron monitors) as Ground Level Enhancements (GLEs). Some of the GLEs originate from high energy solar neutrons which are produced in association with solar flares. These neutrons are also observed by ground-based neutron monitors and solar neutron telescopes. Recently, some of the solar neutron detectors have also been operating in space. By observing these solar neutrons, we can obtain information about ion acceleration in solar flares. Such neutrons were observed in association with some X-class flares in solar cycle 23, and sometimes they were observed by two different types of detectors. For example, on 2005 September 7, large solar neutron signals were observed by the neutron monitor at Mt. Chacaltaya in Bolivia and Mexico City, and by the solar neutron telescopes at Chacaltaya and Mt. Sierra Negra in Mexico in association with an X17.0 flare. The neutron signal continued for more than 20 minutes with high statistical significance. Intense gamma-ray emission was also registered by INTEGRAL, and by RHESSI during the decay phase. We analyzed these data using the solar-flare magnetic-loop transport and interaction model of Hua et al. (2002), and found that the model could successfully fit the data with intermediate values of loop magnetic convergence and pitch angle scattering parameters. These results indicate that solar neutrons were produced at the same time as the gamma-ray line emission and that ions were continuously accelerated at the emission site. In this paper, we introduce some of the solar neutron observations in solar cycle 23, and discuss the tendencies of the physical parameters of solar neutron GLEs, and the energy spectrum and population of the

  12. A New Deep, Hard X-ray Survey of M31: Monitoring Black Hole and Neutron Star Accretion States in the X-ray Binary Population of Our Nearest Neighbor

    NASA Astrophysics Data System (ADS)

    Wik, Daniel R.; Hornschemeier, Ann E.; Yukita, Mihoko; Ptak, Andrew; Lehmer, Bret; Maccarone, Thomas J.; Antoniou, Vallia; Zezas, Andreas; Harrison, Fiona; Stern, Daniel; Venters, Tonia M.; Williams, Benjamin F.; Eracleous, Michael; Plucinsky, Paul P.; Pooley, David A.

    2016-01-01

    X-ray binaries (XRBs) trace old and new stellar populations in galaxies, and thus star formation history and star formation rate. X-ray emission from XRBs may be responsible for significant amounts of heating of the early Intergalactic Medium at Cosmic Dawn and may also play a significant role in reionization. Until recently, the hard emission from these populations could only be studied for XRBs in our own galaxy, where it is often difficult to measure accurate distances and thus luminosities. The launch of NuSTAR, the first focusing hard X-ray observatory, has allowed us to resolve the brightest XRBs (down to LX ~ few times 1038 erg/s) in galaxies like NGC 253, M83, and M82 up to 4 Mpc away. To reach much lower X-ray luminosities that are more typical of XRBs in the Milky Way (LX <~ 1037 erg/s), we have observed M31 in 3 NuSTAR fields, up to 5 visits apiece for more than 1 Ms total exposure, mostly within the footprint of the Panchromatic Hubble Andromeda Treasury (PHAT) Survey. Our monitoring campaign reveals over 40 accreting black holes and neutron stars -- distinguished from each other by their spectral shape in the hard band -- some of which undergo state changes over the month-long timescales captured by our legacy survey to date. We also discuss implications for this updated understanding of XRB populations on early-Universe measurements in, e.g., the 7 Ms Chandra Deep Field survey.

  13. Dosimetry in mixed neutron-gamma fields

    SciTech Connect

    Remec, I.

    1998-04-01

    The gamma field accompanying neutrons may, in certain circumstances, play an important role in the analysis of neutron dosimetry and even in the interpretation of radiation induced steel embrittlement. At the High Flux Isotope Reactor pressure vessel the gamma induced reactions dominate the responses of {sup 237}Np and {sup 238}U dosimeters, and {sup 9}Be helium accumulation fluence monitors. The gamma induced atom displacement rate in steel is higher than corresponding neutron rate, and is the cause of ``accelerated embrittlement`` of HFIR materials. In a large body of water, adjacent to a fission plate, photofissions contribute significantly to the responses of fission monitors and need to be taken into account if the measurements are used for the qualification of the transport codes and cross-section libraries.

  14. Dibaryons in neutron stars

    NASA Technical Reports Server (NTRS)

    Olinto, Angela V.; Haensel, Pawel; Frieman, Joshua A.

    1991-01-01

    The effects are studied of H-dibaryons on the structure of neutron stars. It was found that H particles could be present in neutron stars for a wide range of dibaryon masses. The appearance of dibaryons softens the equations of state, lowers the maximum neutron star mass, and affects the transport properties of dense matter. The parameter space is constrained for dibaryons by requiring that a 1.44 solar mass neutron star be gravitationally stable.

  15. Neutron removal cross section as a measure of neutron skin

    SciTech Connect

    Fang, D. Q.; Ma, Y. G.; Cai, X. Z.; Tian, W. D.; Wang, H. W.

    2010-04-15

    We study the relation between neutron removal cross section (sigma{sub -N}) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between sigma{sub -N} and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

  16. A Neutron Spectrometer for Small Satellite Opportunities

    NASA Astrophysics Data System (ADS)

    de Nolfo, Georgia; Bloser, Peter; Dumonthier, J.; Garcia-Burgos, A.; Ryan, James Michael; Suarez, G.; Winkert, G. E.

    2015-04-01

    The detection of fast neutrons has important implications in such diverse fields as geospace physics, solar physics, and applications within Defense and Security programs. In particular, neutrons provide key observations that complement gamma-ray observations in understanding the magnetic topology and particle acceleration processes at the Sun. Solar neutrons have been observed by space-based missions such as CGRO/COMPTEL and ground-based neutron monitors with energies > 20 MeV. Below 20 MeV, given the neutron half-life of ~15min, the detection of neutrons must take place close to the Sun. The challenge is to build instrumentation that conforms to small satellite platforms making inner heliospheric observations possible as well as Earth-orbiting CubeSats. Scintillator-based technologies have a proven track record for the detection of fast neutrons with high stopping power, good energy resolution, and fast timing. Modern organic scintillators such as stilbene and p-terphenyl, offer improved light output and pulse shape discrimination — the ability to distinguish gamma from neutron-induced signals. Modern readout devices such as silicon photomultipliers (SiPMs) offer an ideal alternative to photomultiplier tubes given their inherently compact size and the very low operating voltages required. The combination of modern scintillators and silicon photomultipliers enables new designs for instruments that conform to small satellite platforms such as CubeSats. We discuss the performance of a double scatter neutron spectrometer based on p-terphenyl coupled to arrays of silicon photomultipliers for readout. In addition, we present preliminary results for pulse shape discrimination using advanced waveform digitization techniques.

  17. Spin distribution in neutron induced preequilibrium reactions

    SciTech Connect

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

    2005-10-04

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

  18. Arsenic activation neutron detector

    DOEpatents

    Jacobs, Eddy L.

    1981-01-01

    A detector of bursts of neutrons from a deuterium-deuteron reaction includes a quantity of arsenic adjacent a gamma detector such as a scintillator and photomultiplier tube. The arsenic is activated by the 2.5 Mev neutrons to release gamma radiation which is detected to give a quantitative representation of detected neutrons.

  19. Arsenic activation neutron detector

    DOEpatents

    Jacobs, E.L.

    1980-01-28

    A detector of bursts of neutrons from a deuterium-deuteron reaction includes a quantity of arsenic adjacent a gamma detector such as a scintillator and photomultiplier tube. The arsenic is activated by the 2.5-MeV neutrons to release gamma radiation which is detected to give a quantitative representation of detected neutrons.

  20. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  1. Perforated diode neutron sensors

    NASA Astrophysics Data System (ADS)

    McNeil, Walter J.

    A novel design of neutron sensor was investigated and developed. The perforated, or micro-structured, diode neutron sensor is a concept that has the potential to enhance neutron sensitivity of a common solid-state sensor configuration. The common thin-film coated diode neutron sensor is the only semiconductor-based neutron sensor that has proven feasible for commercial use. However, the thin-film coating restricts neutron counting efficiency and severely limits the usefulness of the sensor. This research has shown that the perforated design, when properly implemented, can increase the neutron counting efficiency by greater than a factor of 4. Methods developed in this work enable detectors to be fabricated to meet needs such as miniaturization, portability, ruggedness, and adaptability. The new detectors may be used for unique applications such as neutron imaging or the search for special nuclear materials. The research and developments described in the work include the successful fabrication of variant perforated diode neutron detector designs, general explanations of fundamental radiation detector design (with added focus on neutron detection and compactness), as well as descriptive theory and sensor design modeling useful in predicting performance of these unique solid-state radiation sensors. Several aspects in design, fabrication, and operational performance have been considered and tested including neutron counting efficiency, gamma-ray response, perforation shapes and depths, and silicon processing variations. Finally, the successfully proven technology was applied to a 1-dimensional neutron sensor array system.

  2. LGB neutron detector

    NASA Astrophysics Data System (ADS)

    Quist, Nicole

    2012-10-01

    The double pulse signature of the Gadolinium Lithium Borate Cerium doped plastic detector suggests its effectiveness for analyzing neutrons while providing gamma ray insensitivity. To better understand this detector, a californium gamma/neutron time of flight facility was constructed in our lab. Reported here are efforts to understand the properties and applications of the LGB detector with regards to neutron spectroscopy.

  3. Computer-assisted warehouse personnel scheduling

    NASA Astrophysics Data System (ADS)

    Parker, Sandra C.; Malstrom, Eric J.; Usmani, Tariq

    1992-02-01

    A decision support system is developed for personnel scheduling in a multiple warehouse environment. The system incorporates current manpower level, historical data of workers used, empirical load distributions, and performance standards to generate manpower requirements for a specified planning horizon. The software has been developed to be easily adaptable to varying situational details, therefore is widely applicable in different warehouse settings. The system offers personnel managers a valuable tool for evaluating alternative schedules and making intelligent decisions regarding personnel scheduling in warehouses.

  4. Personnel administration can act on cost containment.

    PubMed

    Adams, J

    1980-01-01

    Hosiptal personnel administration programs have the potential to contain costs in a variety of areas, including human resources management, payroll costs, benefits costs, labor turnover, and recruitment costs. Recognizing this, the Maine Society for Hospital Personnel Administration presented a seminar and prepared a guide for trustees and administrators on the role that personnel administration can play in the Voluntary Effort to contain costs. The following article is an adaptation of the information included in the seminar and guide.

  5. [Hip replacement in military personnel].

    PubMed

    Maksimov, I B; Paniushin, K A; Brizhan', L K; Buriachenko, B P; Varfolomeev, D I; Mimanchev, O V

    2014-01-01

    Hip joint diseases and injuries are common for orthopedic pathology among military personnel. Hip replacement is one of the most frequent operations. Authors evaluated hip replacement in 136 servicemen treated at the center of traumatology and orthopedics of Burdenko General Military Clinical Hospital of the Ministry of Defense of Russia in 2010-2013. On the basis of the conducted analysis the main disease groups were revealed, peculiarities of pathology among this category of patients. Authors proposed surgical doctrine for the treatment of this contingent. Effective surgical treatment, in particular, hip replacement surgery, conducted with the use of the proposed principles, as a rule, fully functionally cured patients and contributes to return them in the system that contributes to the strengthening of defensibility of the country.

  6. 40 CFR 792.29 - Personnel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Personnel shall take necessary personal sanitation and health precautions designed to avoid contamination of... prevent microbiological, radiological, or chemical contamination of test systems and test, control,...

  7. 33 CFR 127.707 - Security personnel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Security § 127.707 Security personnel. The...

  8. Qualifications and certification of nondestructive testing personnel

    NASA Technical Reports Server (NTRS)

    Kirk, M. K.

    1971-01-01

    Personnel handbook states criteria for test methods including radiation, ultrasonics, eddy current, liquid penetrant, and magnetic particle. Subject categories are thoroughly defined and substructured.

  9. Neutron beam imaging with GEM detectors

    NASA Astrophysics Data System (ADS)

    Albani, G.; Croci, G.; Cazzaniga, C.; Cavenago, M.; Claps, G.; Muraro, A.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Rebai, M.; Tardocchi, M.; Gorini, G.

    2015-04-01

    Neutron GEM-based detectors represent a new frontier of devices in neutron physics applications where a very high neutron flux must be measured such as future fusion experiments (e.g. ITER Neutral beam Injector) and spallation sources (e.g. the European Spallation source). This kind of detectors can be properly adapted to be used both as beam monitors but also as neutron diffraction detectors that could represent a valid alternative for the 3He detectors replacement. Fast neutron GEM detectors (nGEM) feature a cathode composed by one layer of polyethylene and one of aluminium (neutron scattering on hydrogen generates protons that are detected in the gas) while thermal neutron GEM detectors (bGEM) are equipped with a borated aluminium cathode (charged particles are generated through the 10B(n,α)7Li reaction). GEM detectors can be realized in large area (1 m2) and their readout can be pixelated. Three different prototypes of nGEM and one prototype of bGEM detectors of different areas and equipped with different types of readout have been built and tested. All the detectors have been used to measure the fast and thermal neutron 2D beam image at the ISIS-VESUVIO beamline. The different kinds of readout patterns (different areas of the pixels) have been compared in similar conditions. All the detectors measured a width of the beam profile consitent with the expected one. The imaging property of each detector was then tested by inserting samples of different material and shape in the beam. All the samples were correctly reconstructed and the definition of the reconstruction depends on the type of readout anode. The fast neutron beam profile reconstruction was then compared to the one obtained by diamond detectors positioned on the same beamline while the thermal neutron one was compared to the imaged obtained by cadmium-coupled x-rays films. Also efficiency and the gamma background rejection have been determined. These prototypes represent the first step towards the

  10. Interim status report of the TMI personnel-dosimetry project

    SciTech Connect

    Rich, B.L.; Alvarez, J.L.; Adams, S.R.

    1981-06-01

    The current 2-chip TLD personnel dosimeter in use at Three Mile Island (TMI) has been shown inadequate for the anticipated high beta/gamma fields during TMI recovery operations in some areas. This project surveyed the available dosimeter systems, set up an Idaho National Engineering Laboratory (INEL) prototype system, and compared this system with those commercial systems that could be made immediately available for comparison. Of the systems tested, the new INEL personnel dosimeter was found to produce the most accurate results for use in recovery operations at TMI-2. The other multiple-chip or multiple-filter systems were found less desirable at present. The most prominent deficiencies in the INEL dosimeter stem from the fact that it lacks a completely automated reader and its x-ray and thermal neutron responses require additional development. A automated prototype reader system may be in operation by the end of CY-1981. Three alternatives for operational dosimetry are discussed. A combination of a modified version of the presently used Harshaw 2-chip dosimeter and the INEL dosimeter is recommended.

  11. Summary and analsysis of the 1986 ORNL personnel dosimetry intercomparison study

    SciTech Connect

    Swaja, R.E.; Weng, P.S.; Sims, C.S.; Yeh, S.H.

    1987-04-01

    The Twelfth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory (ORNL) during April 14 to 17, 1986. Objectives of this study were to determine neutron dosimeter performance characteristics at neutron dose equivalent levels near the minimum specified for accreditation testing programs and to provide several radiation fields different from those that have been considered in prior ORNL intercomparisons. Dosimeter badges from 49 participating organizations were mounted on Lucite block phantoms and exposed to six mixed-radiation fields (five using the Health Physics Research Reactor and one using a PuBe source) with neutron dose equivalents of about 1.5 mSv and gamma dose equivalents between 0.04 and 5.37 mSv. Results of this study indicated that participants had no difficulty obtaining measurable indication of neutron exposure at dose equivalent levels of about 1.5 mSv. Average neutron results for all dosimeter types were within approximately 60% of reference values with hard spectra being more accurately measured than soft spectra. Considering all irradiations, albedo and direct interaction TLD systems provided about the same performance characteristics. With regard to precision, about 58% of the reported neutron results had single standard deviations within 10% at the means which indicates that precision was not a problem relative to accuracy for over half of the participants. Average gamma results varied from 0.98 to 2.22 times reference values for all exposures with TLD systems being more accurate than film. Some participants, especially those using film, had difficulty obtaining measurable indication of gamma exposures at dose equivalent levels lower than 0.09 mSv. About 69% of all neutron results and 77% of all gamma results met regulatory standards for measurement accuracy and approximately 65% of all neutron data satisfied national dosimetry accreditation criteria for accuracy plus precision. 18 refs., 1 fig., 30 tabs.

  12. Grazing incidence neutron optics

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2012-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20 .ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  13. Grazing Incidence Neutron Optics

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2013-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20.ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  14. Organic metal neutron detector

    DOEpatents

    Butler, Michael A.; Ginley, David S.

    1987-01-01

    A device for detecting neutrons comprises a layer of conductive polymer sandwiched between electrodes, which may be covered on each face with a neutron transmissive insulating material layer. Conventional electrodes are used for a non-imaging integrating total neutron fluence-measuring embodiment, while wire grids are used in an imaging version of the device. The change in conductivity of the polymer after exposure to a neutron flux is determined in either case to provide the desired data. Alternatively, the exposed conductive polymer layer may be treated with a chemical reagent which selectively binds to the sites altered by neutrons to produce an image of the flux detected.

  15. Neutron scatter camera

    DOEpatents

    Mascarenhas, Nicholas; Marleau, Peter; Brennan, James S.; Krenz, Kevin D.

    2010-06-22

    An instrument that will directly image the fast fission neutrons from a special nuclear material source has been described. This instrument can improve the signal to background compared to non imaging neutron detection techniques by a factor given by ratio of the angular resolution window to 4.pi.. In addition to being a neutron imager, this instrument will also be an excellent neutron spectrometer, and will be able to differentiate between different types of neutron sources (e.g. fission, alpha-n, cosmic ray, and D-D or D-T fusion). Moreover, the instrument is able to pinpoint the source location.

  16. Production of Samples of Individual Radioxenon Isotopes Through Neutron Irradiation of Stable Xenon Gas

    DTIC Science & Technology

    2008-09-01

    Whitney, S. C. (2006). Light-Element Neutron Depth Profiling at the University of Texas. MS Thesis, University of Texas at Austin. 2008 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies 757

  17. ReactorHealth Physics operations at the NIST center for neutron research.

    PubMed

    Johnston, Thomas P

    2015-02-01

    Performing health physics and radiation safety functions under a special nuclear material license and a research and test reactor license at a major government research and development laboratory encompasses many elements not encountered by industrial, general, or broad scope licenses. This article reviews elements of the health physics and radiation safety program at the NIST Center for Neutron Research, including the early history and discovery of the neutron, applications of neutron research, reactor overview, safety and security of radiation sources and radioactive material, and general health physics procedures. These comprise precautions and control of tritium, training program, neutron beam sample processing, laboratory audits, inventory and leak tests, meter calibration, repair and evaluation, radioactive waste management, and emergency response. In addition, the radiation monitoring systems will be reviewed including confinement building monitoring, ventilation filter radiation monitors, secondary coolant monitors, gaseous fission product monitors, gas monitors, ventilation tritium monitor, and the plant effluent monitor systems.

  18. Ionization signals from diamond detectors in fast-neutron fields

    NASA Astrophysics Data System (ADS)

    Weiss, C.; Frais-Kölbl, H.; Griesmayer, E.; Kavrigin, P.

    2016-09-01

    In this paper we introduce a novel analysis technique for measurements with single-crystal chemical vapor deposition (sCVD) diamond detectors in fast-neutron fields. This method exploits the unique electronic property of sCVD diamond sensors that the signal shape of the detector current is directly proportional to the initial ionization profile. In fast-neutron fields the diamond sensor acts simultaneously as target and sensor. The interaction of neutrons with the stable isotopes 12 C and 13 C is of interest for fast-neutron diagnostics. The measured signal shapes of detector current pulses are used to identify individual types of interactions in the diamond with the goal to select neutron-induced reactions in the diamond and to suppress neutron-induced background reactions as well as γ-background. The method is verified with experimental data from a measurement in a 14.3 MeV neutron beam at JRC-IRMM, Geel/Belgium, where the 13C(n, α)10Be reaction was successfully extracted from the dominating background of recoil protons and γ-rays and the energy resolution of the 12C(n, α)9Be reaction was substantially improved. The presented analysis technique is especially relevant for diagnostics in harsh radiation environments, like fission and fusion reactors. It allows to extract the neutron spectrum from the background, and is particularly applicable to neutron flux monitoring and neutron spectroscopy.

  19. Trace Gas Monitoring

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Space technology is contributing to air pollution control primarily through improved detectors and analysis methods. Miniaturized mass spectrometer is under development to monitor vinyl chloride and other hydrocarbon contaminants in an airborne laboratory. Miniaturized mass spectrometer can be used to protect personnel in naval and medical operations as well as aboard aircraft.

  20. Meteorological Monitoring Program

    SciTech Connect

    Hancock, H.A. Jr.; Parker, M.J.; Addis, R.P.

    1994-09-01

    The purpose of this technical report is to provide a comprehensive, detailed overview of the meteorological monitoring program at the Savannah River Site (SRS) near Aiken, South Carolina. The principle function of the program is to provide current, accurate meteorological data as input for calculating the transport and diffusion of any unplanned release of an atmospheric pollutant. The report is recommended for meteorologists, technicians, or any personnel who require an in-depth understanding of the meteorological monitoring program.

  1. Comparison of Fast Neutron Detector Technologies

    SciTech Connect

    Stange, Sy; Mckigney, Edward Allen

    2015-02-09

    This report documents the work performed for the Department of Homeland Security Domestic Nuclear Detection O ce as the project Fast Neutron Detection Evaluation under contract HSHQDC-14-X-00022. This study was performed as a follow-on to the project Study of Fast Neutron Signatures and Measurement Techniques for SNM Detection - DNDO CFP11-100 STA-01. That work compared various detector technologies in a portal monitor con guration, focusing on a comparison between a number of fast neutron detection techniques and two standard thermal neutron detection technologies. The conclusions of the earlier work are contained in the report Comparison of Fast Neutron Detector Technologies. This work is designed to address questions raised about assumptions underlying the models built for the earlier project. To that end, liquid scintillators of two di erent sizes{ one a commercial, o -the-shelf (COTS) model of standard dimensions and the other a large, planer module{were characterized at Los Alamos National Laboratory. The results of those measurements were combined with the results of the earlier models to gain a more complete picture of the performance of liquid scintillator as a portal monitor technology.

  2. Radiation-Related Risk Analysis for Atmospheric Flight Civil Aviation Flight Personnel

    NASA Technical Reports Server (NTRS)

    DeAngelis, G.; Wilson, J. W.

    2003-01-01

    Human data on low dose rate radiation exposure and consequent effects are not readily available, and this fact generates groundtruth concerns for all risk assessment techniques for possible health effects induced by the space radiation environment, especially for long term missions like those foreseen now and in the near future. A large amount of such data may be obtained through civil aviation flight personnel cohorts, in the form of epidemiological studies on delayed health effects induced by the cosmic-ray generated atmospheric radiation environment, a high- LET low dose and low dose rate ionizing radiation with its typical neutron component, to which flight personnel are exposed all throughout their work activity. In the perspective of worldwide studies on radiation exposure of the civil aviation flight personnel, all the available results from previous studies on flight personnel radiation exposure have been examined in various ways (i.e. literature review, meta-analysis) to evaluate possible significant associations between atmospheric ionizing radiation environment and health risks, and to assess directions for future investigations. The physical characteristics of the atmospheric ionizing radiation environment make the results obtained for atmospheric flight personnel relevant for space exploration.

  3. Ultracold neutron detector for neutron lifetime measurements

    NASA Astrophysics Data System (ADS)

    Andreev, V.; Vassiljev, A.; Ivanov, E.; Ilyin, D.; Krivshich, A.; Serebrov, A.

    2017-02-01

    The gas-filled detector of ultracold neutrons has been designed and constructed for the spectrometer of the neutron lifetime measurements at the ILL, Grenoble, France. The detector has been successfully tested and is currently being used at this spectrometer. We could show that minimization of the ;wall; effect is a key factor to ensure efficient background suppression and to maximize the detection efficiency. This effect is primarily related to the composition of the gas mixture, which crucially depends on the neutron velocity spectrum.

  4. NEUTRON DENSITY CONTROL IN A NEUTRONIC REACTOR

    DOEpatents

    Young, G.J.

    1959-06-30

    The method and means for controlling the neutron density in a nuclear reactor is described. It describes the method and means for flattening the neutron density distribution curve across the reactor by spacing the absorbing control members to varying depths in the central region closer to the center than to the periphery of the active portion of the reactor to provide a smaller neutron reproduction ratio in the region wherein the members are inserted, than in the remainder of the reactor thereby increasing the over-all potential power output.

  5. 21 CFR 606.20 - Personnel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Personnel. 606.20 Section 606.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS CURRENT GOOD MANUFACTURING PRACTICE FOR BLOOD AND BLOOD COMPONENTS Organization and Personnel §...

  6. 21 CFR 211.28 - Personnel responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Personnel responsibilities. 211.28 Section 211.28 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Organization and Personnel §...

  7. 21 CFR 225.10 - Personnel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Personnel. 225.10 Section 225.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS General Provisions § 225.10 Personnel....

  8. 21 CFR 225.10 - Personnel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Personnel. 225.10 Section 225.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS General Provisions § 225.10 Personnel....

  9. 21 CFR 225.10 - Personnel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Personnel. 225.10 Section 225.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS General Provisions § 225.10 Personnel....

  10. 21 CFR 225.10 - Personnel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Personnel. 225.10 Section 225.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS General Provisions § 225.10 Personnel....

  11. 21 CFR 211.25 - Personnel qualifications.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Personnel qualifications. 211.25 Section 211.25 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Organization and Personnel §...

  12. 21 CFR 225.10 - Personnel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Personnel. 225.10 Section 225.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS General Provisions § 225.10 Personnel....

  13. 21 CFR 820.25 - Personnel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... QUALITY SYSTEM REGULATION Quality System Requirements § 820.25 Personnel. (a) General. Each manufacturer... their specific jobs. (2) Personnel who perform verification and validation activities shall be made aware of defects and errors that may be encountered as part of their job functions....

  14. 9 CFR 2.32 - Personnel qualifications.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Personnel qualifications. 2.32 Section 2.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.32 Personnel qualifications. (a) It shall...

  15. 9 CFR 2.32 - Personnel qualifications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Personnel qualifications. 2.32 Section 2.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.32 Personnel qualifications. (a) It shall...

  16. 9 CFR 2.32 - Personnel qualifications.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Personnel qualifications. 2.32 Section 2.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.32 Personnel qualifications. (a) It shall...

  17. 34 CFR 300.207 - Personnel development.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Personnel development. 300.207 Section 300.207 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION... CHILDREN WITH DISABILITIES Local Educational Agency Eligibility § 300.207 Personnel development. The...

  18. The Quiet Revolution in Public Personnel Laws

    ERIC Educational Resources Information Center

    Couturier, Jean J.

    1976-01-01

    Discusses Chicago's recent adoption of a new personnel system patterned closely after the Model Public Personnel Administration Law developed by the National Civil Service League (NCSL). Describes major provisions of NCSL's model law and relates the process used by NCSL to develop, evaluate, and encourage adoption of the model law. (JG)

  19. Management & Supervision Personnel Administration Training; General Reference.

    ERIC Educational Resources Information Center

    United States Government Printing Office, Washington, DC. Training and Career Development Div.

    This report lists 329 books in the library of the Training and Career Development Division of the Personnel Service. The books are listed under six categories. They are: personnel administration (46), management and supervision (60), general reference (57), training (20), American Management Association (AMA) publications (118), and United States…

  20. Managing the Reduction in Military Personnel

    DTIC Science & Technology

    1990-07-01

    second, and possibly third reenlistments; and selection of some personnel for early retirement . A Sustaining Level of Accessions. The long-term size...Air Force might be selected for involuntary early retirement in 1991. This number would represent about 5 percent of personnel eligible for retirement