Science.gov

Sample records for mev synchrocyclotron semiannual

  1. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    NASA Astrophysics Data System (ADS)

    Abrosimov, N. K.; Gavrikov, Yu A.; Ivanov, E. M.; Karlin, D. L.; Khanzadeev, A. V.; Yalynych, N. N.; Riabov, G. A.; Seliverstov, D. M.; Vinogradov, V. M.

    2006-05-01

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of ±1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  2. Residual radioactivity at the CERN 600 MeV synchro-cyclotron

    NASA Astrophysics Data System (ADS)

    Carbonez, P.; La Torre, F. P.; Michaud, R.; Silari, M.

    2012-12-01

    The 600 MeV synchro-cyclotron (SC) was the first accelerator that came into operation at CERN in 1957. It provided beams for CERN's first particle and nuclear physics experiments and operated for 33 years until it was shut down in 1990. In view of a planned partial decommissioning of the facility, a range of measurements were carried out to evaluate the levels of residual radioactivity in the accelerator and its surrounding after about 20 years of cooling time. Gamma spectrometry measurements were performed on 113 samples collected inside the three floors of the accelerator vault, on the cyclotron itself and on concrete samples taken from various parts of the building walls, up to a depth of 50 cm in the shield. About 40% of all samples contain traces of neutron-induced radionuclides, mainly 60Co (in metals), 133Ba, 137Cs, 152Eu and 154Eu (in concrete). Values of specific activities range from 5 mBq/g to 781 Bq/g. The maximum activity induced in concrete was observed at the depth of 40 cm in the wall near the cyclotron extraction channel. The laboratory measurements were supplemented by in-situ gamma spectrometry performed with the ISOCS system. A complete dose rate survey was also performed yielding isodose maps of the three levels of the building. The isotope production and the residual radioactivity in the barite walls of the SC bunker were simulated with the FLUKA and JEREMY codes in use at CERN for predicting residual radioactivity in activated accelerator components, and the results compared with the gamma spectrometry data. A detailed comparison of calculated and measured specific activities shows generally good agreement, to within a factor 2 in most cases. These results serve as indirect validation of the capabilities of these codes to correctly predict residual radioactivity with only a very approximate knowledge of the irradiation profile and after a very long (20 years) cooling time. Overall the results provided in this paper may be of use for

  3. Commercial accelerators: Compact superconducting synchrocyclotrons with magnetic field up to 10 T for proton and carbon therapy

    NASA Astrophysics Data System (ADS)

    Papash, A. I.; Karamysheva, G. A.; Onishchenko, L. M.

    2012-11-01

    Based on a brief review of accelerators widely used for proton-ion therapy and for curing patients over the last 20 years, the necessity and feasibility of creating compact superconducting synchrocyclotrons with a magnetic field value up to 10 T are outlined. The main component of modern commercial facilities for proton-ion therapy is an isochronous cyclotron with room-temperature or superconducting coils which accelerates protons to 250 MeV or a synchrophasotron with carbon-ion energy reaching 400 MeV/nucleon. Usually the ions are delivered from the accelerator to the medical-treatment room via transport lines, while irradiation is produced by means of a system that is comprised of pointing magnets, collimators, and energy degraders mounted on a rotating gantry. To greatly reduce the price of the facility (by an order of magnitude) and to facilitate the work of hospital personnel, the isocentric rotation of a compact superconducting synchrocyclotron around the patient is proposed. Estimates of the physical and technical parameters of the facility are given.

  4. 78 FR 44307 - Semiannual Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... July 23, 2013 Part XIV Department of the Treasury Semiannual Regulatory Agenda #0;#0;Federal Register / Vol. 78 , No. 141 / Tuesday, July 23, 2013 / Unified Agenda#0;#0; ] DEPARTMENT OF THE TREASURY 31 CFR Subtitles A and B Semiannual Agenda AGENCY: Department of the Treasury. ACTION: Semiannual regulatory...

  5. Brief overview of the creation of the synchrocyclotron at the hydrotechnical laboratory of the USSR Academy of Sciences and first results of physical studies: Review of archival documents

    NASA Astrophysics Data System (ADS)

    Kiselev, G. V.; Rusakovich, N. A.

    2012-07-01

    A review of the archive's documents on the main stages of the creation of the synchrocyclotron at the Hydrotechnical Laboratory (now known as the Dzhelepov Laboratory of Nuclear Problems) is presented. The review is based on minutes of the Special Committee and Scientific and Technical Council (NTS), which belongs to the First Chief Directorate (PGU) concerning the era of the Soviet atomic project (1945-1953). The analysis of these minutes has enabled us to prepare a chronicle of events that deal with the creation of the synchrocyclotron, as well as the discussion of the project and its place of construction, the research and development program, and so on. The minutes of two NTS meetings dated May 5 and 12, 1952 are devoted to discussing the results the research and development program in 1950-1951. The minutes of NTS meetings have not been published previously.

  6. New laser setup for the selective isotope production and investigation in a laser ion source at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron) facility

    SciTech Connect

    Barzakh, A. E.; Fedorov, D. V.; Ivanov, V. S.; Molkanov, P. L.; Panteleev, V. N.; Volkov, Yu. M.

    2012-02-15

    New laser installation for the resonance ionization spectroscopy in a laser ion source and for rare isotope production has been recently put into operation at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron) facility (Petersburg Nuclear Physics Institute, Gatchina). This is a significant improvement of a previous target-laser ion source device of the IRIS mass-separator, working on-line with 1 GeV proton beam of PNPI (Petersburg Nuclear Physics Institute) synchrocyclotron. It makes possible for us to get the isobarically clean radioactive isotope beams of a great number of chemical elements. New laser setup provides the two- or three-resonance step ionization in the range of wavelength of 265-850 nm. The first results obtained at the laser setup for Tl isotopes are presented.

  7. 75 FR 79929 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... Commission ###Semiannual Regulatory Agenda### ] FEDERAL TRADE COMMISSION (FTC) FEDERAL TRADE COMMISSION 16 CFR Ch. I Semiannual Regulatory Agenda AGENCY: Federal Trade Commission. ACTION: Semiannual regulatory... 22(d)(1) of the Federal Trade Commission Act, 15 U.S.C. 57b-3(d)(1), and the Regulatory......

  8. Federal Trade Commission Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... Part XX Federal Trade Commission Semiannual Regulatory Agenda ] FEDERAL TRADE COMMISSION (FTC) FEDERAL TRADE COMMISSION 16 CFR Ch. I Semiannual Regulatory Agenda AGENCY: Federal Trade Commission... published in accordance with section 22(d)(1) of the Federal Trade Commission Act, 15 U.S.C.......

  9. 76 FR 40050 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... July 7, 2011 Part VII Department of Energy Semiannual Regulatory Agenda #0;#0;Federal Register / Vol. 76 , No. 130 / Thursday, July 7, 2011 / Unified Agenda#0;#0; ] DEPARTMENT OF ENERGY 10 CFR Chs. II, III, and X 48 CFR Ch. 9 Semiannual Regulatory Agenda AGENCY: Department of Energy. ACTION: Notice...

  10. 78 FR 1570 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... January 8, 2013 Part VII Department of Energy Semiannual Regulatory Agenda #0;#0;Federal Register / Vol. 78 , No. 5 / Tuesday, January 8, 2013 / Unified Agenda#0;#0; ] DEPARTMENT OF ENERGY 10 CFR Chs. II, III, and X 48 CFR Ch. 9 Semiannual Regulatory Agenda AGENCY: Department of Energy. ACTION: Notice...

  11. Small Business Administration Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... businesses. Timetable: Action Date FR Cite NPRM 08/00/10 Regulatory Flexibility Analysis Required: Yes Agency... Manufacturing Assistance Act of 2004 (Reauthorization Act) to regulate Small Business Lending Companies (SBLCs... Part XVI Small Business Administration Semiannual Regulatory Agenda ] SMALL...

  12. 12 CFR 8.2 - Semiannual assessment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... follows: If the bank's total assets (consolidated domestic and foreign subsidiaries) are: Over— But not... national bank falls into one of the asset-size brackets denoted by Columns A and B. A bank's semiannual..., which is computed on the assets of the bank up to the lower endpoint (Column A) of the bracket in...

  13. Department of Defense Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... American Act. Timetable: Action Date FR Cite NPRM 06/00/10 Regulatory Flexibility Analysis Required: Yes... DoD oversight of contractor business systems. Timetable: Action Date FR Cite NPRM 01/15/10 75 FR 2457... Part V Department of Defense Semiannual Regulatory Agenda ] DEPARTMENT OF DEFENSE (DOD)...

  14. Environmental Protection Agency Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ...:// Not in FR www.epa.gov/lawsregs/search/regagenda.html Semiannual Regulatory Flexibility Agenda www....html issue ] Monthly Action Initiation List http://www.regulations.gov/fdmspublic/component/ Not in FR... Rulemaking Gateway www.epa.gov/rulemaking/ Not in FR B. What Are EPA's Regulatory Goals, and What...

  15. Department of Interior Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ...: Action Date FR Cite Final Action 04/00/10 Regulatory Flexibility Analysis Required: Yes Agency Contact... idle facilities. Timetable: Action Date FR Cite NPRM 12/00/10 NPRM Comment Period End 02/00/11... Part IX Department of the Interior Semiannual Regulatory Agenda ] DEPARTMENT OF THE INTERIOR...

  16. Department of Energy Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... OF ENERGY Semiannual Regulatory Agenda 10 CFR Chs. II, III, and X 48 CFR Ch. 9 Regulatory Agenda... Review,'' 58 FR 51735, and the Regulatory Flexibility Act, 5 U.S.C. 601 et seq. SUPPLEMENTARY INFORMATION... and direct heating equipment. This is the second review for water heaters. Timetable: Action Date...

  17. Department of Energy Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... Semiannual Regulatory Agenda 10 CFR Chs. II, III, and X 48 CFR Ch. 9 Regulatory Agenda AGENCY: Department of... ``Regulatory Planning and Review,'' 58 FR 51735, and the Regulatory Flexibility Act, 5 U.S.C. 601 et seq... use throughout the rulemaking process. Timetable: Action Date FR Cite Notice: Public Meeting...

  18. 77 FR 8020 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... time limitations for veteran-owned small businesses. Completed: Reason Date FR Cite Withdrawn 10/24/11... Agenda for the agency. SBA's last semiannual regulatory agenda was published on July 7, 2011, at 76 FR... Industries. 465 Small Business Size 3245-AG28 Standards: Real Estate, Rental and Leasing Industries....

  19. 76 FR 40136 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... tolling of time limitations for veteran-owned small businesses. Timetable: Action Date FR Cite NPRM 08/00... FR 79864. The semiannual agenda of the SBA conforms to the Unified Agenda format developed by the... Services Industries. 309 Small Business Size 3245-AG28 Standards: Real Estate, Rental and...

  20. 78 FR 44331 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... published on January 8, 2013, at 78 FR 1636. The Semiannual Agenda of the SBA conforms to the Unified Agenda... collection and use of individual SBDC client data. Timetable: Action Date FR Cite NPRM 10/00/13 Regulatory... Loan Program; Export Express Program Legal Authority: 15 U.S.C. 636(a)(31) and (35) Abstract: SBA...

  1. 78 FR 11735 - Semiannual Regulatory Agenda; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... FURTHER INFORMATION CONTACT: Mariana A. Pardo, Director, Government Contracting and Business Development... From the Federal Register Online via the Government Publishing Office ] Vol. 78 Tuesday, No. 33... 8, 2013 (78 FR 1636). The regulatory agenda is a semiannual summary of all current and...

  2. Nuclear Regulatory Commission Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... agenda on April 26, 2010 (75 FR 21960). For this edition of the NRC's regulatory agenda, the most... publication of the last NRC semiannual agenda on April 26, 2010 (75 FR 21960). Within each group, the rules... regulations to improve the control over the distribution of source material to exempt persons and to...

  3. Nuclear Regulatory Commission Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... December 7, 2009 (74 FR 64572). ADDRESSES: Comments on any rule in the agenda may be sent to the Secretary... occurred on rules since publication of the last NRC semiannual agenda on December 7, 2009 (74 FR 64572... regulations to improve the control over the distribution of source material to exempt persons and to...

  4. 76 FR 40144 - Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Aeronautics and Space Administration (NASA). ACTION: Semiannual regulatory agenda. SUMMARY: This agenda... INFORMATION: DoD, GSA, and NASA, under their several statutory authorities, jointly issue and maintain the FAR..., Director, Office of Acquisition Policy and Senior Procurement Executive. DOD/GSA/NASA (FAR)--Proposed...

  5. 41 CFR 105-69.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Semi-annual compilation. 105-69.600 Section 105-69.600 Public Contracts and Property Management Federal Property Management... Administration 69-NEW RESTRICTIONS ON LOBBYING Agency Reports § 105-69.600 Semi-annual compilation. (a) The...

  6. 6 CFR 9.51 - Semi-annual compilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 6 Domestic Security 1 2012-01-01 2012-01-01 false Semi-annual compilation. 9.51 Section 9.51 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY RESTRICTIONS UPON LOBBYING Agency Reports § 9.51 Semi-annual compilation. (a) The head of each agency shall collect and compile...

  7. 38 CFR 45.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Semi-annual compilation. 45.600 Section 45.600 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) NEW RESTRICTIONS ON LOBBYING Agency Reports § 45.600 Semi-annual compilation. (a) The head...

  8. 77 FR 25523 - Semi-Annual Workforce Management Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... Office of the Secretary Semi-Annual Workforce Management Conference AGENCY: U.S. Department of... of Transportation, Office of the Secretary, announces the second Semi-Annual Workforce Management... for addressing labor/management issues, and safety. Registration Space is limited. Registration...

  9. 32 CFR 28.600 - Semi-annual compilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Semi-annual compilation. 28.600 Section 28.600... REGULATIONS NEW RESTRICTIONS ON LOBBYING Agency Reports § 28.600 Semi-annual compilation. (a) The head of each... compilations to the Secretary of the Senate and the Clerk of the House of Representatives. (h) Agencies...

  10. 6 CFR 9.51 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Semi-annual compilation. 9.51 Section 9.51 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY RESTRICTIONS UPON LOBBYING Agency Reports § 9.51 Semi-annual compilation. (a) The head of each agency shall collect and compile...

  11. First Semiannual Report of the National Aeronautics and Space Administration

    NASA Technical Reports Server (NTRS)

    Glennan, T. Keith

    1959-01-01

    The First Semiannual Report of the National Aeronautics and Space Administration (NASA) is submitted to Congress pursuant to section 206 (a) of the National Aeronautics and Space Act of 1958 (Public Law 85-568) to provide for research into problems of flight within and outside the Earth's atmosphere, which states: The Administration shall submit to the President for transmittal to Congress, semiannually and at such other times as it deems desirable, a report on its activities and accomplishments.

  12. 31 CFR Appendix B to Part 359 - Composite Semiannual Rate Period Table

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Composite Semiannual Rate Period Table... SAVINGS BONDS, SERIES I Pt. 359, App. B Appendix B to Part 359—Composite Semiannual Rate Period Table 1. What months make up the composite semiannual rate period? You may use the following table to find...

  13. 31 CFR Appendix B to Part 359 - Composite Semiannual Rate Period Table

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Composite Semiannual Rate Period... SAVINGS BONDS, SERIES I Pt. 359, App. B Appendix B to Part 359—Composite Semiannual Rate Period Table 1. What months make up the composite semiannual rate period? You may use the following table to find...

  14. 31 CFR Appendix B to Part 359 - Composite Semiannual Rate Period Table

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Composite Semiannual Rate Period Table... SAVINGS BONDS, SERIES I Pt. 359, App. B Appendix B to Part 359—Composite Semiannual Rate Period Table 1. What months make up the composite semiannual rate period? You may use the following table to find...

  15. 31 CFR Appendix B to Part 359 - Composite Semiannual Rate Period Table

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Composite Semiannual Rate Period... SAVINGS BONDS, SERIES I Pt. 359, App. B Appendix B to Part 359—Composite Semiannual Rate Period Table 1. What months make up the composite semiannual rate period? You may use the following table to find...

  16. 31 CFR Appendix B to Part 359 - Composite Semiannual Rate Period Table

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Composite Semiannual Rate Period Table... SAVINGS BONDS, SERIES I Pt. 359, App. B Appendix B to Part 359—Composite Semiannual Rate Period Table 1. What months make up the composite semiannual rate period? You may use the following table to find...

  17. 31 CFR 359.11 - What is the semiannual inflation rate?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What is the semiannual inflation rate... BONDS, SERIES I General Information § 359.11 What is the semiannual inflation rate? The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index...

  18. 31 CFR 359.11 - What is the semiannual inflation rate?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false What is the semiannual inflation rate... BONDS, SERIES I General Information § 359.11 What is the semiannual inflation rate? The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index...

  19. 31 CFR 359.11 - What is the semiannual inflation rate?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false What is the semiannual inflation rate... BONDS, SERIES I General Information § 359.11 What is the semiannual inflation rate? The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index...

  20. 31 CFR 359.11 - What is the semiannual inflation rate?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false What is the semiannual inflation rate... BONDS, SERIES I General Information § 359.11 What is the semiannual inflation rate? The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index...

  1. 31 CFR 359.11 - What is the semiannual inflation rate?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false What is the semiannual inflation rate... BONDS, SERIES I General Information § 359.11 What is the semiannual inflation rate? The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index...

  2. Energy dependence of proton induced fission cross sections for heavy nuclei in the energy range 200-1000 MeV

    SciTech Connect

    Kotov, A. A.; Vaishnene, L. A.; Vovchenko, V. G.; Gavrikov, Yu. A.; Poliakov, V. V.; Tverskoy, M. G.; Fedorov, O. Ya.; Chestnov, Yu. A.; Shchetkovskiy, A. I.; Shvedchikov, A. V.; Doroshenko, A. Yu.; Fukahori, T.

    2006-09-15

    Total cross sections for proton induced fission of {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu nuclei were measured in the range 200-1000 MeV with an energy step of 100 MeV. The experiment was carried out at 1 GeV in a PNPI synchrocyclotron. Complementary fragments of the binary fission from a thin target were detected in coincidence by two parallel plate avalanche counters (PPAC) located close to the target. An assembly of the two PPACs and with the target in between them was placed directly into the beam, which provided a large solid angle acceptance. The beam monitoring system employed a scintillation counter telescope that was used for direct proton counting as well as for registration of the elastic pp-scattering events from the auxiliary (CH{sub 2}){sub n} target. The measured energy dependence of the total fission cross sections is presented. The results are compared with other available experimental data as well as with calculations in the frame of the cascade-evaporation model.

  3. Proton-Proton Scattering at 105 Mev and 75 Mev

    DOE R&D Accomplishments Database

    Birge, R. W.; Kruse, U. E.; Ramsey, N. F.

    1951-01-31

    The scattering of protons by protons provides an important method for studying the nature of nuclear forces. Recent proton-proton scattering experiments at energies as high as thirty Mev{sup 1} have failed to show any appreciable contribution to the cross section from higher angular momentum states, but it is necessary to bring in tensor forces to explain the magnitude of the observed cross section.

  4. 44 CFR 18.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Semi-annual compilation. 18.600 Section 18.600 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL NEW RESTRICTIONS ON LOBBYING Agency Reports § 18.600...

  5. 40 CFR 34.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34.600 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE NEW RESTRICTIONS ON LOBBYING Agency Reports § 34.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see appendix B) and, on May 31 and November...

  6. Semiannual Report to Congress, October 1, 2002-March 31, 2003.

    ERIC Educational Resources Information Center

    Office of Inspector General (ED), Washington, DC.

    This semiannual report to Congress by the Office of Inspector General (OIG), U.S. Department of Education, covers the actions of the OIG from October 1, 2002, through March 31, 2003. The report discusses four goals of the President's Management Agenda: (1) improved financial performance: includes information on financial statement audits,…

  7. 45 CFR 604.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Agency Reports § 604.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see Appendix B) and, on May 31 and November 30 of each...

  8. 45 CFR 604.600 - Semi-annual compilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Agency Reports § 604.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see Appendix B) and, on May 31 and November 30 of each...

  9. 45 CFR 604.600 - Semi-annual compilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Agency Reports § 604.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see appendix B) and, on May 31 and November 30 of each...

  10. 45 CFR 604.600 - Semi-annual compilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Agency Reports § 604.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see Appendix B) and, on May 31 and November 30 of each...

  11. 45 CFR 604.600 - Semi-annual compilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NEW RESTRICTIONS ON LOBBYING Agency Reports § 604.600 Semi-annual compilation. (a) The head of each agency shall collect and compile the disclosure reports (see Appendix B) and, on May 31 and November 30 of each...

  12. 13 CFR 146.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Semi-annual compilation. 146.600 Section 146.600 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW RESTRICTIONS ON LOBBYING.... (c) Information that involves intelligence matters shall be reported only to the Select Committee...

  13. 45 CFR 1168.600 - Semi-annual compilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Semi-annual compilation. 1168.600 Section 1168.600 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports § 1168.600...

  14. 45 CFR 1168.600 - Semi-annual compilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Semi-annual compilation. 1168.600 Section 1168.600 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports § 1168.600...

  15. 48 CFR 1422.406-13 - Semiannual enforcement reports.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Semiannual enforcement reports. 1422.406-13 Section 1422.406-13 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Labor Standards for...

  16. 48 CFR 1422.406-13 - Semiannual enforcement reports.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Semiannual enforcement reports. 1422.406-13 Section 1422.406-13 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Labor Standards for...

  17. 48 CFR 1422.406-13 - Semiannual enforcement reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Semiannual enforcement reports. 1422.406-13 Section 1422.406-13 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR SOCIOECONOMIC PROGRAMS APPLICATION OF LABOR LAWS TO GOVERNMENT ACQUISITIONS Labor Standards for...

  18. 45 CFR 1168.600 - Semi-annual compilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Semi-annual compilation. 1168.600 Section 1168.600 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports § 1168.600...

  19. 45 CFR 1168.600 - Semi-annual compilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Semi-annual compilation. 1168.600 Section 1168.600 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports § 1168.600...

  20. 45 CFR 1168.600 - Semi-annual compilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Semi-annual compilation. 1168.600 Section 1168.600 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports § 1168.600...

  1. Proposed geomagnetic control of semiannual waves in the mesospheric zonal wind

    NASA Technical Reports Server (NTRS)

    Belmont, A. D.; Nastrom, G. D.; Mayr, H. G.

    1975-01-01

    The polar semiannual oscillation in zonal wind explains midwinter weakening of the polar vortex and the relatively short stratospheric and mesospheric summer easterlies. The phase of the wind oscillation is equinoctial, as is the phase of the semiannual component in magnetic storm activity. For a given altitude, the contours of amplitude of the semiannual wind oscillation have less variability in geomagnetic than in geographic coordinates. It is suggested that the polar wind oscillations are caused by the semiannual maxima in magnetic storm activity, which lead to electron dissociation of O2 into O, in turn increasing ozone more rapidly than the dissociation of N2 destroys ozone, and inducing a semiannual variation in the thermal and wind fields. This implies that geomagnetic processes may cause or affect the development of sudden warmings. As the tropical semiannual wind oscillation is symmetric about the geomagnetic equator, the same processes may also influence the location of the tropical wind wave.

  2. 40 CFR 60.1895 - If a semiannual report is required, when must I submit it?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false If a semiannual report is required, when must I submit it? 60.1895 Section 60.1895 Protection of Environment ENVIRONMENTAL PROTECTION..., 1999 Model Rule-Reporting § 60.1895 If a semiannual report is required, when must I submit it? (a)...

  3. 40 CFR 60.1420 - If a semiannual report is required, when must I submit it?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false If a semiannual report is required, when must I submit it? 60.1420 Section 60.1420 Protection of Environment ENVIRONMENTAL PROTECTION... § 60.1420 If a semiannual report is required, when must I submit it? (a) For data collected during...

  4. 40 CFR 62.15350 - If a semiannual report is required, when must I submit it?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false If a semiannual report is required, when must I submit it? 62.15350 Section 62.15350 Protection of Environment ENVIRONMENTAL PROTECTION... it? (a) For data collected during the first half of a calendar year, submit your semiannual report...

  5. Semiannually alternating exchange of intermediate waters east of the Philippines

    NASA Astrophysics Data System (ADS)

    Wang, Fan; Song, Lina; Li, Yuanlong; Liu, Chuanyu; Wang, Jianing; Lin, Pengfei; Yang, Guang; Zhao, Jun; Diao, Xinyuan; Zhang, Dongxiao; Hu, Dunxin

    2016-07-01

    Intermediate water exchange in the northwest tropical Pacific is explored with the temperature, salinity, and current measurements of a mooring system deployed at 8°N, 127.05°E during 2010-2014. For the first time, prominent semiannual variability (SAV; with the maximum power at ~ 187 days) of subthermocline meridional flow along the Mindanao coast is revealed. A significant correlation between meridional flow and salinity is found at intermediate depths. This provides direct evidence for the alternating transports of South Pacific and North Pacific Intermediate Waters by northward and southward undercurrents, respectively. Further analysis with an eddy-resolving ocean general circulation model demonstrates that the SAV is generated locally near the western boundary, manifesting as large-scale subthermocline recirculation and leading to alternating northward and southward flows near the Mindanao coast, which plays an efficient role in the intermediate water exchange of the northwest tropical Pacific. Mechanisms underlying the observed SAV are discussed.

  6. MODIS Science Team Member Semi-annual Report

    NASA Technical Reports Server (NTRS)

    Vermote, Eric; ElSaleous, Nazmi; Fisher, Paul; Karakos, Damianos; Ray, James; Vermeulen, Anne

    1998-01-01

    This paper presents a semi-annual report of the MODerate resolution imaging Spectroradiometer (MODIS) Science Team Members. The most important activities undertaken during this reporting period are the following: 1) Versions 2.1 and 2.2 surface reflectance L2/L3 DAAC/SDST delivery; 2) Version 2.0 1km and 250m VI product delivery (assist Arizona); 3) Version 2.1 surface reflectance L2 testing; 4) Land Synthetic data set generator improvements; 5) QA; 6) Surface reflectance error budget generation (SWAMP request); 7) SCF Hardware; 8) Aerosol transport modeling; 9) Aerosol optical depth retrieval from AVHRR data; 10) Aerosol characteristics retrieval from SeaWIFS/AVHRR fusioned data; 11) Validation activities; 12) Aerosol climatology; and 13) 6S code. The report includes summaries of the topics above.

  7. Semiannual report to Congress, October 1, 1994--March 31, 1995

    SciTech Connect

    1995-04-01

    The Office of Inspector General Semiannual Report to the Congress covers the period October 1, 1994, through March 31, 1995. The report summarizes significant audit, inspection and investigative accomplishments for the reporting period, a large number of which facilitated Department management`s efforts to improve management controls and ensure efficient and effective operation. Narratives of the most significant reports are grouped by six primary performance measures: (1) Recommendations accepted by management, (2) Audit/inspection savings, recoveries, and funds identified for better use, (3) Legislative/regulatory compliance to recommendations, (4) Positive impacts on the Department after implementation of recommendations, (5) Complaints resolved, and (6) Investigation recoveries, fines, and funds identified for better use.

  8. CO2 annual and semiannual cycles from multiple satellite retrievals and models

    NASA Astrophysics Data System (ADS)

    Jiang, Xun; Crisp, David; Olsen, Edward T.; Kulawik, Susan S.; Miller, Charles E.; Pagano, Thomas S.; Liang, Maochang; Yung, Yuk L.

    2016-02-01

    Satellite CO2 retrievals from the Greenhouse gases Observing SATellite (GOSAT), Atmospheric Infrared Sounder (AIRS), and Tropospheric Emission Spectrometer (TES) and in situ measurements from the National Oceanic and Atmospheric Administration - Earth System Research Laboratory (NOAA-ESRL) Surface CO2 and Total Carbon Column Observing Network (TCCON) are utilized to explore the CO2 variability at different altitudes. A multiple regression method is used to calculate the CO2 annual cycle and semiannual cycle amplitudes from different data sets. The CO2 annual cycle and semiannual cycle amplitudes for GOSAT XCO2 and TCCON XCO2 are consistent but smaller than those seen in the NOAA-ESRL surface data. The CO2 annual and semiannual cycles are smallest in the AIRS midtropospheric CO2 compared with other data sets in the Northern Hemisphere. The amplitudes for the CO2 annual cycle and semiannual cycle from GOSAT, TES, and AIRS CO2 are small and comparable to each other in the Southern Hemisphere. Similar regression analysis is applied to the Model for OZone And Related chemical Tracers-2 and CarbonTracker model CO2. The convolved model CO2 annual cycle and semiannual cycle amplitudes are similar to those from the satellite CO2 retrievals, although the models tend to underestimate the CO2 seasonal cycle amplitudes in the Northern Hemisphere midlatitudes and underestimate the CO2 semiannual cycle amplitudes in the high latitudes. These results can be used to better understand the vertical structures for the CO2 annual cycle and semiannual cycle and help identify deficiencies in the models, which are very important for the carbon budget study.

  9. Solar Rotational Periodicities and the Semiannual Variation in the Solar Wind, Radiation Belt, and Aurora

    NASA Technical Reports Server (NTRS)

    Emery, Barbara A.; Richardson, Ian G.; Evans, David S.; Rich, Frederick J.; Wilson, Gordon R.

    2011-01-01

    The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from S to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005 -2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (approx.1980, approx.1990, and approx. 2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995-1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27 -day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the > 2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods

  10. ETAII 6 MEV PEPPERPOT EMITTANCE MEASUREMENT

    SciTech Connect

    Paul, A C; Richardson, R; Weir, J

    2004-10-18

    We measured the beam emittance at the ETAII accelerator using a pepper-pot diagnostic at nominal parameters of 6 MeV and 2000 Amperes. During the coarse of these experiments, a ''new tune'' was introduced which significantly improved the beam quality. The source of a background pedestal was investigated and eliminated. The measured ''new tune'' emittance is {var_epsilon}= 8.05 {plus_minus} 0. 53 cm - mr or a normalized emittance of {var_epsilon}{sub n} = 943 {plus_minus} 63 mm - mr In 1990 the ETAII programmatic emphasis was on free electron lasers and the paramount parameter was whole beam brightness. The published brightness for ETAII after its first major rebuild was J = 1 - 3 x 10{sup 8} A/(m - rad){sup 2} at a current and energy of 1000-1400 Amperes and 2.5 MeV. The average normalized emittance derived from table 2 of that report is 864 mm-mr corresponding to a real emittance of 14.8 cm-mr.

  11. Low-rank coal research semiannual report, January 1992--June 1992

    SciTech Connect

    Not Available

    1992-12-31

    This semiannual report is a compilation of seventeen reports on ongoing coal research at the University of North Dakota. The following research areas are covered: control technology and coal preparation; advanced research and technology development; combustion; liquefaction and gasification. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  12. Unified agenda of federal regulatory and deregulatory actions--HHS. Semiannual regulatory agenda.

    PubMed

    1998-04-27

    The President's Executive Order 12866 and the Regulatory Flexibility Act of 1980 require the semiannual publication of an agenda which summarizes all current, projected, and recently completed rulemakings of the Department. The agenda enables the public to know about and to participate in the Department's regulations development work. The last such agenda was published on October 29, 1997.

  13. Fusion materials semiannual progress report for period ending December 31, 1999

    SciTech Connect

    Burn, G.

    2000-03-01

    This is the twenty-seventh in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components.

  14. 25 CFR 141.24 - Attendance at semi-annual meetings.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Attendance at semi-annual meetings. 141.24 Section 141.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at...

  15. 25 CFR 141.24 - Attendance at semi-annual meetings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Attendance at semi-annual meetings. 141.24 Section 141.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at...

  16. 25 CFR 141.24 - Attendance at semi-annual meetings.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Attendance at semi-annual meetings. 141.24 Section 141.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at...

  17. 25 CFR 141.24 - Attendance at semi-annual meetings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Attendance at semi-annual meetings. 141.24 Section 141.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at...

  18. 78 FR 1618 - Semiannual Agenda and Fiscal Year 2013 Regulatory Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... to the requirements of the Regulatory Flexibility Act and Executive Order (E.O.) 12866 (``Regulatory Planning and Review''), which require the publication by the Department of a semiannual agenda of regulations. E.O. 12866 also requires the publication by the Department of a regulatory plan for the...

  19. 75 FR 41878 - Semi-Annual Labor Standards Enforcement Report-Local Contracting Agencies (HUD Programs)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-19

    ... URBAN DEVELOPMENT Semi-Annual Labor Standards Enforcement Report--Local Contracting Agencies (HUD... Development, 451 Seventh Street, SW., Washington, DC 20410; e-mail Leroy McKinney Jr. at Leroy.McKinneyJr@hud... public that the Department of Housing and Urban Development has submitted to OMB a request for...

  20. 25 CFR 141.24 - Attendance at semi-annual meetings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Attendance at semi-annual meetings. 141.24 Section 141.24 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at...

  1. State Research Coordinating Unit Activities for the Period July 1, 1971-December 31, 1971. Semiannual Report.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC.

    This semiannual report summarizes research activities of the State Research Coordinating Units conducted under Section 131(b) of the Vocational Education Amendments of 1968 during the first half of fiscal year 1972. The purpose of the report is to facilitate exchange of information and reduce duplication of effort among the states by providing…

  2. Inspector General's Semiannual Report to Congress, No. 55. April 1, 2007-September 30, 2007

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    This semiannual report to Congress on the activities and accomplishments of the Office of Inspector General (OIG), U.S. Department of Education (Department) from April 1, 2007, through September 30, 2007, highlights the audits, inspections, investigations, and other activities to illustrate an ongoing commitment to promoting accountability,…

  3. Semi-Annual Report to Congress: October 1, 1983-March 31, 1984. No. 8.

    ERIC Educational Resources Information Center

    Office of Inspector General (ED), Washington, DC.

    This eighth semi-annual report issued by the United States Department of Education's Office of Inspector General (OIG) summarizes the activities and accomplishments of that office during a 6-month period ending March 31, 1984. A condensation of audits of Department of Education programs presents statistics on OIG activities and the allocation of…

  4. Semiannual report to Congress, October 1, 1995--March 31, 1996

    SciTech Connect

    1996-04-01

    This Office of Inspector General Semiannual Report to the Congress covers the period from October 1, 1995, through March 31, 1996. The report summarizes significant audit, inspection, and investigative accomplishments for the reporting period, a large portion of which facilitated Department of Energy management efforts to improve management controls and ensure efficient and effective operation of its programs. A major accomplishment during this period was the completion of financial statement audits for Fiscal Year 1995. Annual financial statement audits are mandated by the Chief Financial Officers Act of 1990. Narratives of our most significant reports are grouped by measures which the Office of Inspector General uses to gauge its performance. The common thread that ties the performance measures together is their emphasis on supporting Department efforts to produce high quality products at the lowest possible cost to the taxpayer. During this reporting period, the Office of Inspector General issued 67 audit and 15 inspection reports. For reports issued during the period, the Office of Inspector General made audit recommendations that, when implemented by management, could result in $134.6 million being put to better use. Management committed to taking corrective actions which the Office of Inspector General estimates will result in a more efficient use of funds totaling $333.2 million. Office of Inspector General investigations led to 6 criminal convictions and 1 pretrial diversion, as well as criminal and civil prosecutions which resulted in fines and recoveries of $10,942,714. The Office of Inspector General also provided 33 investigative referrals to management for recommended positive action.

  5. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    SciTech Connect

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R.; Hong-Nian Jow

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

  6. The stratopause semiannual oscillation in the NCAR Community Climate Model

    NASA Technical Reports Server (NTRS)

    Sassi, Fabrizio; Garcia, Roland R.; Boville, Byron A.

    1993-01-01

    The middle atmospheric version of the NCAR Community Climate Model (CCM2) has been used to study the development of the equatorial semiannual oscillation (SAO) in the stratosphere. The model domain extends from the ground to about 80 km, with a vertical resolution of 1 km. Transport of nitrous oxide (N2O) with simplified photochemistry is included in the calculation to illustrate the influence of tropical circulations on the distribution of trace species. Diagnosis of model output reveals two distinct phases in the evolution of the zonal mean state on the equator. In early December, a strong and broad easterly jet appears near the stratopause in connection with a midlatitude wave event (sudden stratospheric warming) that reverses the winter westerlies of the Northern Hemisphere throughout the upper stratosphere. When the wave forcing dies out, the radiative drive allows the westerlies to recover at midlatitudes, while easterlies persist in the tropics. The resulting strong meridional gradient of the zonal mean wind provides favorable conditions for the development of inertial instability at lower latitudes. The meridional circulation associated with the instability shapes the 'nose' of the easterly jet, reducing the extension of the unstable region. In equinoctial conditions, a jet of westerlies appears in the lower equatorial mesosphere and descends to lower altitudes; positive accelerations associated with the descending westerlies are due primarily to Kelvin waves. The descent of the westerly jet does not reproduce well the observed behavior of the SAO westerly phase, either in amplitude or in the extent of downward propagation. As a consequence, the model does not simulate the 'double peak' observed in the tropical distribution of N2O. Comparison of wave amplitudes in the model with those derived from satellite observations shows that the calculated amplitudes are larger than observed in the upper stratosphere. It follows that inadequate Kelvin wave forcing is

  7. Valine radiolysis by MeV ions

    NASA Astrophysics Data System (ADS)

    Da Silveira, Enio

    2016-07-01

    Valine, (CH3)2 CHCH (NH2) COOH, is a protein amino acid that has been identified in extraterrestrial environments and in the Murchison meteorite [1]. The knowledge of half-lives of small organic molecules under ionizing radiation is important for the setup of models describing the spread out of prebiotics across the Solar System or the Galaxy. We have investigated typical effects of MeV cosmic ray ions on prebiotic molecules in laboratory by impinging ions produced by the PUC-Rio Van de Graaff accelerator. Pure valine films, deposited by evaporation on KBr substrates, were irradiated by H ^{+}, He ^{+} and N ^{+} ion beams, from 0.5 to 1.5 MeV and up to a fluence of 10 ^{15} projectiles/cm ^{2}. The sample temperature was varied from 10 K to 300 K. The irradiation was interrupted several times for Mid-FTIR analysis of the sample. The main findings are: 1- The column density of the valine decreases exponentially with fluence. 2- In some cases, a second exponential appears in the beginning of irradiation; this feature has been attributed to sample compaction by the ion beam [2]. 3- Destruction cross sections of valine are in the 10 ^{-15} cm ^{2} range, while compaction cross sections are in the 10 ^{-14} cm ^{2} range. 4- Destruction cross section increases with the stopping power of the beam and also with the sample temperature. 5- Surprisingly, during the radiolysis of valine, just CO _{2} is seen by as a daughter molecule formed in the bulk. 6- After long beam fluence, also a CO peak appears in the infrared spectrum; this species is however interpreted as a fragment of the formed CO2 molecules. 7- Considering the flux ratio between laboratory experiments and actual galactic cosmic rays, half-life of valine is predicted for ISM conditions [3]. This work on pure valine is the first measurement of a series. New experiments are planned for determining cross sections of valine dissolved in H _{2}O or CO _{2}, inspired by the study performed for glycine [4]. [1] P

  8. Level Density of COBALT-57 in the Energy Region 1 Mev to 14 Mev

    NASA Astrophysics Data System (ADS)

    Mishra, Vivek

    The level density of ^{57 }Co is studied in the energy region of 1-14 MeV using three experimental techniques. Levels are counted in the resolved region, evaporation spectra are measured in the resolved to continuum region, and the coherence width is measured in the region of level overlap. Use of Hauser-Feshbach fits to the evaporation cross sections requires level densities of the residual nucleus. A two -parameter based Fermi gas form is used for the calculation of level density as a function of the nuclear excitation energy. This procedure enables level density calculation beyond the energy region in which the two fixed parameters provide the best fits to the data. A comparison is made between the level density obtained from the above described methods and the predictions of the microscopic model in an energy range of 1-20 MeV. This model utilizes a BCS pairing Hamiltonian and specific sets of single particle states and calculates numerical values of the level density. Comparisons are also made with level density of ^{57 }Co obtained in various other studies. Both the resolved level studies and the fits to the evaporation spectra were conducted using the ^{56}Fe(d,n)^{57 }Co and ^{57}Fe(p,n) ^{57}Co reactions. Standard neutron time-of-flight techniques including pulse shape discrimination for elimination of gamma -rays were employed. An energy resolution as good as 6 keV at 1-1.5 MeV neutron energy was obtained for high resolution measurements. For Ericson fluctuation measurements, the excitation functions corresponding to the ground state and the first two excited states of the residual nucleus in the ^{56}Fe(p,n) ^{56}Co reaction were obtained for lab angles between 0^circ and 150^circ. The ^{56}Fe(d,n) ^{57}Co reaction proves to be very selective in populating resolved states and includes substantial contributions from mechanisms other than the compound nuclear. The ^{57 }Fe(p,n)^{57}Co reaction populated 14 previously unknown levels. The fits to the

  9. Office of Inspector General semiannual report to Congress, October 1, 1996--March 31, 1997

    SciTech Connect

    1997-04-01

    This Office of Inspector General Semiannual Report to the Congress covers the period from October 1, 1996, through March 31, 1997. The report summarizes significant audit, inspection, and investigative accomplishments for the reporting period which facilitated Department of Energy management efforts to improve management controls and ensure efficient and effective operation of its programs. Narratives of the most significant reports are grouped by measures which the Office of Inspector General uses to gauge its performance. The common thread that ties the performance measures together is their emphasis on supporting Department efforts to produce high quality products at the lowest possible cost to the taxpayer. Five such performance measures were used during this semiannual period to present outcomes of Office of Inspector General work in terms of improvements in Department programs and operations.

  10. Equatorial ionosphere semiannual oscillation investigated from Schumann resonance measurements on board the C/NOFS satellite

    NASA Astrophysics Data System (ADS)

    Simões, Fernando; Pfaff, Robert; Freudenreich, Henry; Klenzing, Jeffrey; Rowland, Douglas; Bromund, Kenneth; Kepko, Larry; Le, Guan; Liebrecht, Maria Carmen; Martin, Steven; Uribe, Paulo

    2013-11-01

    of Schumann resonance signatures in the equatorial ionosphere offers remote sensing capabilities for the investigation of tropospheric and space weather effects in the ionosphere. Schumann resonances are electromagnetic oscillations in the earth-ionosphere cavity produced by lightning activity. Analysis of AC electric field measurements gathered by the Communications/Navigation Outage Forecasting System satellite reveals a semiannual pattern in Schumann resonance data recorded during nighttime in the equatorial ionosphere. This pattern observed in the Schumann resonance amplitude is expected to help validate—or at least constrain—potential mechanisms proposed to explain the semiannual oscillation observed in different geophysical records, such as those reported in a variety of tropospheric, ionospheric/thermospheric, and magnetospheric observations.

  11. Unified agenda of federal regulatory and deregulatory actions--HHS. Semiannual regulatory agenda.

    PubMed

    1998-11-01

    The President's Executive Order 12866 and the Regulatory Flexibility Act of 1980 require the semiannual publication of an agenda which summarizes all current, projected, and recently completed rulemakings of the Department. The agenda informs the public about regulatory actions that are under development within the components of the Department, and it provides all concerned with the opportunity to participate in this work at an early stage. The last such agenda was published on April 27, 1998.

  12. National Institute for Global Environmental Change. Semi-annual report, July 1, 1991--December 31, 1991

    SciTech Connect

    Werth, G.C.

    1992-04-01

    This document is the Semi-Annual Report of the National Institute for Global Environmental Change for the reporting period July 1 to December 31, 1991. The report is in two parts. Part I presents the mission of the Institute, examples of progress toward that mission, a brief description of the revised management plan, and the financial report. Part II presents the statements of the Regional Center Directors along with progress reports of the projects written by the researchers themselves.

  13. Origins of the semiannual variation of geomagnetic activity in 1954 and 1996

    NASA Astrophysics Data System (ADS)

    Cliver, E.; Svalgaard, L.; Ling, A.

    2004-01-01

    . We investigate the cause of the unusually strong semiannual variation of geomagnetic activity observed in the solar minimum years of 1954 and 1996. For 1996 we separate the contributions of the three classical modulation mechanisms (axial, equinoctial, and Russell-McPherron) to the six-month wave in the index and find that all three contribute about equally. This is in contrast to the longer run of geomagnetic activity (1868-1998) over which the equinoctial effect accounts for 70% of the semiannual variation. For both 1954 and 1996, we show that the Russell-McPherron effect was enhanced by the Rosenberg-Coleman effect (an axial polarity effect) which increased the amount of the negative (toward Sun) [positive (away from Sun)] polarity field observed during the first [second] half of the year; such fields yield a southward component in GSM coordinates. Because this favourable condition occurs only for alternate solar cycles, the marked semiannual variation in 1954 and 1996 is a manifestation of the 22-year cycle of geomagnetic activity. The 11-year evolution of the heliospheric current sheet (HCS) also contributes to the strong six-month wave during these years. At solar minimum, the streamer belt at the base of the HCS is located near the solar equator, permitting easier access to high speed streams from polar coronal holes when the Earth is at its highest heliographic latitudes in March and September. Such an axial variation in solar wind speed was observed for 1996 and is inferred for 1954.

  14. CO2 Annual and Semiannual Cycles from Satellite Retrievals and Models

    NASA Astrophysics Data System (ADS)

    Jiang, X.; Crisp, D.; Olsen, E. T.; Kulawik, S. S.; Miller, C. E.; Pagano, T. S.; Yung, Y. L.

    2014-12-01

    We have compared satellite CO2 retrievals from the Greenhouse gases Observing SATellite (GOSAT), Atmospheric Infrared Sounder (AIRS), and Tropospheric Emission Spectrometer (TES) with in-situ measurements from the Earth System Research Laboratory (NOAA-ESRL) Surface CO2 and Total Carbon Column Observing Network (TCCON), and utilized zonal means to characterize variability and distribution of CO2. In general, zonally averaged CO2 from the three satellite data sets are consistent with the surface and TCCON XCO2 data. Retrievals of CO2 from the three satellites show more (less) CO2 in the northern hemisphere than that in the southern hemisphere in the northern hemispheric winter (summer) season. The difference between the three satellite CO2 retrievals might be related to the different averaging kernels in the satellites CO2 retrievals. A multiple regression method was used to calculate the CO2 annual cycle and semiannual cycle amplitudes from different satellite CO2 retrievals. The CO2 annual cycle and semiannual cycle amplitudes are largest at the surface, as seen in the NOAA-ESRL CO2 data sets. The CO2 annual cycle and semiannual cycle amplitudes in the GOSAT XCO2, AIRS mid-tropospheric CO2, and TES mid-tropospheric CO2 are smaller compared with those from the surface CO2. Similar regression analysis was applied to the Model for OZone And Related chemical Tracers-2 (MOZART-2) and CarbonTracker model CO2. The convolved model CO2 annual cycle and semiannual cycle amplitudes are similar to those from the satellite CO2 retrievals, although the model tends to under-estimate the CO2 seasonal cycle amplitudes in the northern hemisphere mid-latitudes from the comparison with GOSAT and TES CO2 and underestimate the CO2 semi-annual cycle amplitudes in the high latitudes from the comparison with AIRS CO2. The difference between model and satellite CO2 can be used to identify possible deficiency in the model and improve the model in the future.

  15. Effects of MeV ion beam on polymers

    SciTech Connect

    Evelyn, A.L.; Ila, D.; Zimmerman, R.L.; Bhat, K.; Poker, D.B.; Hensley, D.K.

    1997-12-01

    The electronic ({var_epsilon}{sub c}) and nuclear ({var_epsilon}{sub n}) stopping effects produced by 3.5 MeV and 5.0 MeV ion bombardment in polyvinylidine chloride (PVDC), polyethylene (PE) and polyethylene sulfide were studied and compared. To separate these effects the authors chose two bombardment energies and a thin film polymer stacking technique developed in house. The resulting stacked layered system consisting of each polymer was bombarded with 3.5 MeV and 5.0 MeV alpha particles. The layered system was selected such that the first few layers experience most of the effects of the electronic energy deposited and the last layer receives the effects of the nuclear stopping. The electrical conductance and the changes in the chemical structure were measured by direct resistivity measurements, Raman microprobe analysis, RBS, and FTIR. The post-irradiation characterization resolved the effects of the stopping powers on the polymer films.

  16. Production of 14 MeV neutrons by heavy ions

    DOEpatents

    Brugger, Robert M.; Miller, Lowell G.; Young, Robert C.

    1977-01-01

    This invention relates to a neutron generator and a method for the production of 14 MeV neutrons. Heavy ions are accelerated to impinge upon a target mixture of deuterium and tritium to produce recoil atoms of deuterium and tritium. These recoil atoms have a sufficient energy such that they interact with other atoms of tritium or deuterium in the target mixture to produce approximately 14 MeV neutrons.

  17. Time-dependent 2.2 MeV and 0.5 MeV lines from solar flares

    NASA Technical Reports Server (NTRS)

    Wang, H. T.; Ramaty, R.

    1975-01-01

    The time dependences of the 2.2 MeV and 0.51 MeV gamma ray lines from solar flares are calculated and the results are compared with observations of the 1972, August 4 and 7 flares. Time lag between the nuclear reactions and the formation of these two lines are caused, respectively, by capture of the neutrons, and by deceleration of the positrons and decay of the radioactive nuclei. Results show that the calculation is consistent with the observed rise of the 2.2 MeV line on August 4, and it does not require different time dependences for the accelerated protons and electrons in the flare region. The above lags can explain the delayed gamma ray emission observed on August 7. Positrons of energies greater than about 10 MeV could be detected in interplanetary space following large solar flares.

  18. Randomized equivalence trial of intensive and semiannual applications of fluoride varnish in the primary dentition.

    PubMed

    Weinstein, P; Spiekerman, C; Milgrom, P

    2009-01-01

    For children in the primary dentition with high caries prevalence the standard semiannual application of fluoride varnish may not be successful in preventing tooth decay. Oftentimes this population is mobile and does not receive consistent preventive care. This trial tested whether an intensive fluoride 5% sodium varnish regimen (three applications/2 weeks) applied annually has an equivalent effect on caries progression in the primary dentition compared to single applications applied semiannually. This study was a randomized clinical trial with two treatment groups. All participants (n = 600; mean age +/- SD = 55.3 +/- 4.6 months) received three varnish applications (active varnish or placebo) at semiannual visits over 3 years. Once per year the intensive-treatment group received one set of three active treatments and three placebo treatments 6 months later, each time within 2 weeks. The standard group received one active and two placebo treatments every 6 months. Children were assessed clinically at baseline and 12, 24 and 36 months after the initiation of the study. The mean (SD) numbers of newly decayed primary tooth surfaces observed over 3 years were 9.8 (8.6) and 7.4 (7.7) in the intensive and standard groups, respectively. The adjusted rate ratio was 1.13 (95% CI = 0.94-1.37, p = 0.20). In conclusion, the trial failed to demonstrate clear evidence of a difference in efficacy. However, differences of up to 36% greater rates of caries in the intensive group could not be ruled out, thus equivalence of the treatments cannot be concluded.

  19. Randomized Equivalence Trial of Intensive and Semiannual Applications of Fluoride Varnish in the Primary Dentition

    PubMed Central

    Weinstein, P.; Spiekerman, C.; Milgrom, P.

    2009-01-01

    For children in the primary dentition with high caries prevalence the standard semiannual application of fluoride varnish may not be successful in preventing tooth decay. Oftentimes this population is mobile and does not receive consistent preventive care. This trial tested whether an intensive fluoride 5% sodium varnish regimen (three applications/2 weeks) applied annually has an equivalent effect on caries progression in the primary dentition compared to single applications applied semiannually. This study was a randomized clinical trial with two treatment groups. All participants (n = 600; mean age ± SD = 55.3 ± 4.6 months) received three varnish applications (active varnish or placebo) at semiannual visits over 3 years. Once per year the intensive-treatment group received one set of three active treatments and three placebo treatments 6 months later, each time within 2 weeks. The standard group received one active and two placebo treatments every 6 months. Children were assessed clinically at baseline and 12, 24 and 36 months after the initiation of the study. The mean (SD) numbers of newly decayed primary tooth surfaces observed over 3 years were 9.8 (8.6) and 7.4 (7.7) in the intensive and standard groups, respectively. The adjusted rate ratio was 1.13 (95% CI = 0.94–1.37, p = 0.20). In conclusion, the trial failed to demonstrate clear evidence of a difference in efficacy. However, differences of up to 36% greater rates of caries in the intensive group could not be ruled out, thus equivalence of the treatments cannot be concluded. PMID:20016179

  20. Elastic Neutron Scattering at 96 MeV

    NASA Astrophysics Data System (ADS)

    Hildebrand, A.; Blomgren, J.; Ataç, A.; Bergenwall, B.; Johansson, C.; Klug, J.; Mermod, P.; Nilsson, L.; Pomp, S.; Österlund, M.; Dangtip, s.; Tippawan, U.; Phansuke, P.; Jonsson, O.; Renberg, P.-U.; Prokofiev, A.; Nadel-Turonski, P.; Elmgren, K.; Olsson, N.; Blideanu, V.; Le Brun, C.; Lecolley, J.-F.; Lecolley, F.-R.; Louvel, M.; Marie-Noury, N.; Schweitzer, C.; Eudes, Ph.; Haddad, F.; Lebrun, C.; Koning, A. J.

    2005-05-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20 - 180-MeV neutron beam line of The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12C, 16O, 56Fe, 89Y, and 208Pb has been studied at 96 MeV in the 10 - 70° interval. The results from 12C and 208Pb have recently been published,6 while the data from 16O, 56Fe, and 89Y are under analysis. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated normalization uncertainty, 3%, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic theory. Applications for these measurements are nuclear-waste incineration, single-event upsets in electronics, and fast-neutron therapy.

  1. Solar Gamma Rays Above 8 MeV

    NASA Technical Reports Server (NTRS)

    Crannell, C. J.; Crannell, H.; Ramaty, R.

    1978-01-01

    Processes which lead to the production of gamma rays with energy greater than 8 MeV in solar flares are reviewed and evaluated. Excited states produced by inelastic scattering, charge exchange, and spallation reactions in the abundant nuclear species are considered in order to identify nuclear lines which may contribute to the Gamma ray spectrum of solar flares. The flux of 15.11 MeV Gamma rays relative to the flux of 4.44 MeV Gamma rays from the de-excitation of the corresponding states in C12 is calculated for a number of assumed distributions of exciting particles. This flux ratio is a sensitive diagnostic of accelerated particle spectra. Other high energy nuclear levels are not so isolated as the 15.11 MeV state and are not expected to be so strong. The spectrum of Gamma rays from the decay of Pi dey is sensitive to the energy distribution of particles accelerated to energies greater than 100 MeV.

  2. TFE Verification Program: Semiannual report for the period ending April 30, 1989

    SciTech Connect

    Not Available

    1989-09-01

    The objective of the semiannual progress report is to summarize the technical results obtained during the latest reporting period. The information presented herein will include evaluated test data, design evaluations, the results of analyses and the significance of results. The program objective is to demonstrate the technology readiness of a TFE suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full-power life of 7 years. 55 figs., 30 tabs.

  3. Fusion materials semiannual progress report for the period ending June 30, 1998

    SciTech Connect

    Burn, G.

    1998-09-01

    This is the twenty-fourth in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the US Department of Energy. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  4. Fusion reactor materials semiannual progress report for the period ending March 31, 1993

    SciTech Connect

    Not Available

    1993-07-01

    This is the fourteenth in a series of semiannual technical progress reports on fusion reactor materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the US Depart of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. Separate abstracts were prepared for each individual section.

  5. Collation of monthly and semiannual reports covering instrumentation at the Decade 80 house in Tucson, Arizona

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Decade 80 solar house, located in Tucson, Arizona, was built to show the use of copper in home building and to demonstrate the use of solar energy to provide space heating and cooling and domestic hot water. The auxiliary energy sources are electrical resistance heating for the domestic hot water and a gas fired boiler for space heating and operation of the absorption air conditioning units. The Semi-Annual report gives an overview of the instrumentation effort with the back-up monthly reports reflecting more detail of the effort that went into the implementation of the data acquisition system.

  6. TFE verification program: Semiannual report for the period ending April 30, 1988

    SciTech Connect

    Not Available

    1988-06-01

    The objective of the semiannual progress report is to summarize the technical results obtained during the latest reporting period. The information presented herein will include evaluated test data, design evaluations, the results of analyses and the significance of results. The program objective is to demonstrate the technology readiness of a Thermionic Fuel Element suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full-power life of 7 years. 14 refs., 107 figs., 35 tabs.

  7. Fusion reactor materials: Semiannual progress report for the period ending March 31, 1987

    SciTech Connect

    none,

    1987-09-01

    This is the second in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities in the following areas: (1) Alloy Development for Irradiation Performance; (2) Damage Analysis and Fundamental Studies; and (3) Special Purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials program being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. Separate analytics were prepared for the reports in this volume.

  8. Fusion Materials Semiannual Progress Report for the Period Ending June 30, 1999

    SciTech Connect

    Rowcliffe, A.F.

    1999-09-01

    This is the twenty-sixth in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and its reported separately.

  9. Fusion Materials Semiannual Progress Report for Period Ending December 31, 1998

    SciTech Connect

    Rowcliff, A.F.; Burn, G.

    1999-04-01

    This is the twenty-fifth in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the U.S. Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately.

  10. 10MeV 25KW industrial electron LINAC

    NASA Astrophysics Data System (ADS)

    Kamino, Y.

    1998-06-01

    A 10MeV 25KW plus class electron LINAC was developed for sterilisation of medical devices. The LINAC composed of a standing wave type single cavity prebuncher and a 2m electro-plated travelling wave guide uses a 5MW 2856MHz pulse klystron as an RF source and provides 25KW beam power at the Ti alloy beam window stably after the energy analysing magnet with 10MeV plus-minus 1 MeV energy slit. The practical maximum beam power reached 29 KW and this demonstrated the LINAC as one of the most powerful S-band electron LINACs in the world. The control of the LINAC is fully automated and the "One-Button Operation" is realised, which is valuable for easy operation as a plant system. 2 systems have been delivered and are being operated stably.

  11. Defects and diffusion in MeV implanted silicon

    SciTech Connect

    Venezia, V. C.; Haynes, T. E.; Agarwal, Aditya; Gossmann, H.-J.; Pelaz, L.; Jacobson, D. C.; Eaglesham, D. J.; Duggan, J. L.

    1999-06-10

    In this work we demonstrate that the defects that are created by 2-MeV Si ions can interact with dopant atoms both during implantation and during post-implant annealing. We show that the interstitials and vacancies created during MeV Si implantation result in a radiation enhanced diffusion of B and Sb markers, respectively, when the temperature of implantation is above the threshold temperature for formation of mobile dopant complexes. With the use of these dopant markers we also demonstrate that a vacancy-rich near surface region results during post-implant annealing of MeV implanted silicon. The depth distribution and the thermal evolution of clustered vacancies was measured by a Au labeling technique.

  12. Photon detector for MEGA. [53 MeV

    SciTech Connect

    Gagliardi, C.A.; Tribble, R.E.

    1992-01-01

    The MEGA photon detector is designed to observe the 52.83-MeV photon produced in a [mu] [yields] e[gamma] decay with an energy resolution of 1.25 MeV, a position resolution of 2 [times] 5 mm[sup 2], a directional resolution of 10[degree], a time resolution of 500 ps, and an efficiency of about 5.4%. It will consist of three independent concentric cylindrical pair spectrometers mounted within a 1.5 T magnetic field produced by a superconducting solenoid magnet. Each pair spectrometer includes two thin Pb foils to convert photons into e[sup +]e[sup [minus

  13. Earth albedo neutrons from 10 to 100 MeV.

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Simnett, G. M.; White, R. S.

    1972-01-01

    We report the measurement of the energy and angular distributions of earth albedo neutrons from 10 to 100 MeV at 40 deg N geomagnetic latitude from a balloon at 120,000 ft, below 4.65 g/sq cm. The albedo-neutron omnidirectional energy distribution is flat to 50 MeV, then decreases with energy. The absolute neutron energy distribution is of the correct strength and shape for the albedo neutrons to be the source of the protons trapped in earth's inner radiation belt.

  14. 78 FR 31558 - Medicare Program; Second Semi-Annual Meeting of the Advisory Panel on Hospital Outpatient Payment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... the Advisory Panel on Hospital Outpatient Payment (HOP Panel) August 26-27, 2013 AGENCY: Centers for...: This notice announces the second semi-annual meeting of the Advisory Panel on Hospital Outpatient... Classification (APC) groups and their associated weights, and hospital outpatient therapeutic...

  15. 78 FR 13346 - Medicare Program; Changes to the Semi-Annual Meeting of the Advisory Panel on Hospital Outpatient...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... Federal Register (77 FR 70447) announcing the first semi-annual meeting of the Advisory Panel on Hospital... Meeting of the Advisory Panel on Hospital Outpatient Payment (HOP Panel)--March 11 and March 12, 2013... Panel on Hospital Outpatient Payment (HOP Panel)--March 11 and 12, 2013.'' DATES: Monday, March 11,...

  16. 78 FR 59047 - 30-Day Notice of Proposed Information Collection: Semi-Annual Labor Standards Enforcement Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 30-Day Notice of Proposed Information Collection: Semi-Annual Labor Standards...: Colette Pollard, Reports Management Officer, QDAM, Department of Housing and Urban Development, 451...

  17. U.S. Department of Education, Office of Inspector General Semiannual Report to Congress, April 1, 1997-September 30, 1997.

    ERIC Educational Resources Information Center

    Office of Inspector General (ED), Washington, DC.

    This semiannual report to Congress summarizes the activities of the Department of Education's Office of Inspector General (OIG) for the 6-month period ending September 30, 1997. The OIG gave Congressional testimony regarding the modernization of student-financial-assistance-information programs, the Loan Consolidation process, the Federal Direct…

  18. 78 FR 45260 - 60-Day Notice of Proposed Information Collection: Semi-annual Labor Standards Enforcement Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... URBAN DEVELOPMENT 60-Day Notice of Proposed Information Collection: Semi-annual Labor Standards Enforcement Report- Local Contracting Agencies (HUD Programs) AGENCY: Office of Labor Relation, HUD. ACTION..., Office of labor Relation, Department of Housing and Urban Development, 451 7th Street SW., Room...

  19. Data Summary Report for the 1998 Semiannual Tritium Surveys for Fourmile Branch and the F- and H-Area Seeplines

    SciTech Connect

    Koch, J.

    1999-01-26

    This report presents a summary of the definitive data validation and verification for the 1998 semiannual tritium surveys for Fourmile Branch and the F- and H-Area Seeplines. The project was performed under the direction of WSRC EAS/Ecology. This report was prepared under the direction of EPD/EMS.

  20. 49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false DOT Drug Testing Semi-Annual Laboratory Report to Employers B Appendix B to Part 40 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. B Appendix B to Part 40—DOT Drug...

  1. 49 CFR Appendix C to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to DOT

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Semi-Annual Laboratory Report to DOT Mail, fax, or e-mail to: U.S. Department of Transportation, Office.... Fax: (202) 366-3897. E-mail: ODAPCWebMail@dot.gov. The following items are required on each report...-AM (number) (d) Phencyclidine (number) (e) Amphetamines (number) (1) Amphetamine (number)...

  2. Prospects for Improving Document Delivery. Minutes of the Semiannual Meeting (101st, Arlington, Virginia, October 13-14, 1982).

    ERIC Educational Resources Information Center

    Daval, Nicola, Ed.

    This set of minutes from a semiannual meeting of the Association of Research Libraries (ARL) includes three presentations: "The Economics of Document Delivery" by Donald B. Simpson, "Electronic Journal Publishing and Libraries" by Jay K. Lucker, and "Policies and Controversies" by Hugh C. Atkinson. Atkinson reviews copyright issues,…

  3. Time-dependent 2.2-MeV and 0.5-MeV lines from solar flares

    NASA Technical Reports Server (NTRS)

    Wang, H. T.; Ramaty, R.

    1975-01-01

    The time dependences of the 2.2- and 0.51-MeV gamma-ray lines from solar flares are calculated, and the results are compared with observations of the 1972 August 4 and 7 flares. The time lag between the nuclear reactions and the formation of these two lines is caused by capture of the neutrons and subsequent deceleration of the positrons and decay of the radioactive nuclei. Our main results are that the calculation is consistent with the observed rise of the 2.2-MeV line on August 4, and it does not require different time dependences for the accelerated protons and high-energy electrons in the flare region. The above lags can explain the delayed gamma-ray emission observed on August 7. Positrons of energies greater than about 10 MeV could be detected in interplanetary space following large solar flares.

  4. The development of coal-based technologies for Department of Defense facilities. Volume 2, Appendices. Semiannual technical progress report, September 28, 1994--March 27, 1995

    SciTech Connect

    Miller, B.G.; Bartley, D.A.; Hatcher, P.

    1996-10-15

    This semiannual progress report contains the following appendices: description of the 1,000 lb steam/h watertube research boiler; the Pennsylvania CGE model; Phase II, subtask 3.9 coal market analysis; the CGE model; and sector definition.

  5. The 400 MeV Linac Upgrade at Fermilab

    SciTech Connect

    Noble, R.J.

    1992-12-01

    The Fermilab Linac Upgrade in planned to increase the energy of the H{sup {minus}} linac from 200 to 400 MeV. This is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster which limit either the brightness or the total intensity of the beam. The Linac Upgrade will be achieved by replacing the last four 201.25 MHs drift-tube linac (DTL) tanks which accelerate the beam from 116 to 200 MeV, with seven 805 MRs side-coupled cavity modules operating at an average axial field of about 7.5 MV/meter. This will allow acceleration to 400 MeV in the existing Linac enclosure. Each accelerator module will be driven with a 12 MW klystron-based rf power supply. Three of seven accelerator modules have been fabricated, power tested and installed in their temporary location adjacent to the existing DTL. All seven RF Modulators have been completed and klystron installation has begun. Waveguide runs have completed from the power supply gallery to the accelerator modules. The new linac will be powered in the temporary position without beam in order to verify overall system reliability until the laboratory operating schedule permits final conversion to 400 MeV operation.

  6. 150 MeV proton medical cyclotron design study.

    PubMed

    Burleigh, R J; Clark, D J; Flood, W S

    1975-01-01

    A brief design study has been done for a 150 MeV proton sector cyclotron. The object was to minimize cost but maintain good reliability and easy maintenance. The use of the proton beam would be for therapy, radiography and isotope production.

  7. Inclusive proton reactions at 164 MeV

    NASA Astrophysics Data System (ADS)

    Segel, R. E.; Chen, T.; Rutledge, L. L., Jr.; Maher, J. V.; Wiggins, John; Singh, P. P.; Debevec, P. T.

    1982-12-01

    Singles proton, deuteron, triton, 3He, and alpha spectra resulting from the bombardment of 27Al, 58Ni, 62Ni, and 208Pb targets were measured. Data were taken over the angular range 25°-150°. Most of the data were taken at a bombarding energy of 164 MeV; some data were taken at 100 MeV. The ratios of fast (>30 MeV) particle yields are p:d:t:3He:α~100:10:1:1:1. The deuteron spectra fall off more sharply with exit particle energy than do the proton spectra while tritons fall still more sharply, and the fast 3He and α spectra are similar in shape to the triton spectra. Fast particle angular distributions are all forward peaked with the forward peaking increasing with increasing outgoing particle energy. Angular distributions for the different particle species are quite similar and shapes of both spectral and angular distributions are rather independent of target. Proton and alpha evaporation peaks are prominent, deuterons less so, and evaporation peaks are not apparent in the triton and 3He spectra. NUCLEAR REACTIONS 164, 100 MeV p on 27Al, 58Ni, 62Ni, 208Pb; measured outgoing p, d, t, 3He, α spectra 25°<=θ<=150°.

  8. Analysis of 33 MeV Nitrogen irradiated UHMWPE

    SciTech Connect

    Grosso, Mariela del; Chappa, Veronica; Garcia Bermudez, Gerardo

    2007-10-26

    In this work, we irradiated UHMWPE with 33 MeV Nitrogen ions, at several fluences, to generate surface modifications without affecting the bulk properties. These modifications were quantified by means of wear resistance tests and Fourier transform infrared spectroscopy (FTIR) measurements. Experimental results show an optimum ion fluence value that maximizes UHMWPE wear resistance.

  9. EGRET observations of bursts at MeV energies

    SciTech Connect

    Catelli, J. R.; Schneid, E. J.

    1998-05-16

    We present preliminary results from the analysis of 16 bright bursts that have been observed by the EGRET NaI calorimeter, or TASC. Seven bursts have been imaged in the EGRET spark chamber above 30 MeV, but in most cases the TASC data gives the highest energy spectra available for these bursts. The TASC can obtain spectral and rate information for bursts well outside the field of view of the EGRET spark chambers, and is sensitive in the energy range from 1 to 200 MeV. The spectra for these bursts are mostly consistent with a simple power law with spectral index in the range from 1.7 to 3.7, with several of the brighter bursts showing emission past 100 MeV. No high energy cutoff has been observed. These high energy photons offer important clues to the physical processes involved at the origin of burst emission. For bursts at cosmological distances extremely high bulk Lorentz factors are implied by the presence of MeV and GeV photons which have not been attenuated by pair production with the lower energy photons from the source.

  10. History of the ZGS 500 MeV booster.

    SciTech Connect

    Simpson, J.; Martin; R.; Kustom, R.

    2006-05-09

    The history of the design and construction of the Argonne 500 MeV booster proton synchrotron from 1969 to 1982 is described. This accelerator has since been in steady use for the past 25 years to power the Argonne Intense Pulsed Neutron Source (IPNS).

  11. Tunable nanometer electrode gaps by MeV ion irradiation

    PubMed Central

    Cheang-Wong, J.-C.; Narumi, K.; Schürmann, G. M.; Aziz, M. J.; Golovchenko, J. A.

    2012-01-01

    We report the use of MeV ion-irradiation-induced plastic deformation of amorphous materials to fabricate electrodes with nanometer-sized gaps. Plastic deformation of the amorphous metal Pd80Si20 is induced by 4.64 MeV O2+ ion irradiation, allowing the complete closing of a sub-micrometer gap. We measure the evolving gap size in situ by monitoring the field emission current-voltage (I-V) characteristics between electrodes. The I-V behavior is consistent with Fowler-Nordheim tunneling. We show that using feedback control on this signal permits gap size fabrication with atomic-scale precision. We expect this approach to nanogap fabrication will enable the practical realization of single molecule controlled devices and sensors. PMID:22550357

  12. XRD study of yttria stabilized zirconia irradiated with 7.3 MeV Fe, 10 MeV I, 16 MeV Au, 200 MeV Xe and 2.2 GeV Au ions

    NASA Astrophysics Data System (ADS)

    Nakano, K.; Yoshizaki, H.; Saitoh, Y.; Ishikawa, N.; Iwase, A.

    2016-03-01

    To simulate energetic neutron irradiation effects, yttria-stabilized zirconia (YSZ) which is one of the major materials for electrical corrosion potential sensors (ECP sensors) was irradiated with heavy ions at energies ranging from 7.3 MeV to 2.2 GeV. Ion irradiation effects on the lattice structure were analyzed using the X-ray diffraction (XRD). The increase in lattice constant was induced by the ion irradiation. It was dominated by the elastic collision process and not by the electronic excitation process. The lattice disordering which was observed as a broadening of XRD peaks was also induced by the irradiation especially for 200 MeV Xe ion irradiation. The present result suggests that the expansion and/or the disordering of YSZ lattice induced by energetic neutrons may affect the durability of a joint interface between a metal housing and YSZ membrane for the usage of ECP sensors in nuclear power reactors.

  13. Magnifying lens for 800 MeV proton radiography.

    PubMed

    Merrill, F E; Campos, E; Espinoza, C; Hogan, G; Hollander, B; Lopez, J; Mariam, F G; Morley, D; Morris, C L; Murray, M; Saunders, A; Schwartz, C; Thompson, T N

    2011-10-01

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution. PMID:22047305

  14. Magnifying lens for 800 MeV proton radiography

    NASA Astrophysics Data System (ADS)

    Merrill, F. E.; Campos, E.; Espinoza, C.; Hogan, G.; Hollander, B.; Lopez, J.; Mariam, F. G.; Morley, D.; Morris, C. L.; Murray, M.; Saunders, A.; Schwartz, C.; Thompson, T. N.

    2011-10-01

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  15. Magnifying lens for 800 MeV proton radiography

    SciTech Connect

    Merrill, F. E.; Campos, E.; Espinoza, C.; Hogan, G.; Hollander, B.; Lopez, J.; Mariam, F. G.; Morley, D.; Morris, C. L.; Murray, M.; Saunders, A.; Schwartz, C.; Thompson, T. N.

    2011-10-15

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  16. First Light: MeV Astrophysics from the Moon

    NASA Astrophysics Data System (ADS)

    Miller, Richard S.; Lawrence, David J.

    2016-06-01

    We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5-9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

  17. 5 MeV Mott Polarimeter Development at Jefferson Lab

    SciTech Connect

    Price, J. S.; Sinclair, C. K.; Cardman, L. S.; Haanskneccht, J.; Mack, D. J.; Piot, P.; Assamagan, K. A.; Grames, J.

    1997-01-01

    Low energy (E{sub k}=100 keV) Mott scattering polarimeters are ill- suited to support operations foreseen for the polarized electron injector at Jefferson Lab. One solution is to measure the polarization at 5 MeV where multiple and plural scattering are unimportant and precision beam monitoring is straightforward. The higher injector beam current offsets the lower cross-sections. Recent improvements in the CEBAF injector polarimeter scattering chamber have improved signal to noise.

  18. MeV neutrinos in double {beta} decay

    SciTech Connect

    Zuber, K.

    1997-08-01

    The effect of Majorana neutrinos in the MeV mass range on the double {beta} decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half-life data, limits on the mixing parameter U{sub eh}{sup 2} of the order 10{sup {minus}7} can be derived. Also the possible achievements of upcoming experiments and some consequences are outlined. {copyright} {ital 1997} {ital The American Physical Society}

  19. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    SciTech Connect

    Zeller, A.F.; Ronningen, R.M.; Godeke, A.; Heilbronn, L.H.; McMahan-Norris, P.; Gupta, R.

    2007-11-27

    The use of HTS materials in high radiation environmentsrequires that the superconducting properties remain constant up to aradiation high dose. BSCCO-2223 samples from two manufacturers wereirradiated with 50 MeV protons at fluences of up to 5 x 1017 protons/cm2.The samples lost approximately 75 percent of their pre-irradiation Ic.This compares with Nb3Sn, which loses about 50 percent at the samedisplacements per atom.

  20. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    SciTech Connect

    Zeller, A.F.; Ronningen, R.M.; Godeke, Arno; Heibronn, L.H; McMahan-Norris, P.; Gupta, R.

    2007-11-01

    The use of HTS materials in high radiation environments requires that the superconducting properties remain constant up to a radiation high dose. BSCCO-2223 samples from two manufacturers were irradiated with 50 MeV protons at fluences of up to 5 x 10{sup 17} protons/cm{sup 2}. The samples lost approximately 75% of their pre-irradiation I{sub c}. This compares with Nb{sub 3}Sn, which loses about 50% at the same displacements per atom.

  1. Fission studies with 140 MeV {alpha} particles

    SciTech Connect

    Buttkewitz, A.; Duhm, H. H.; Strauss, W.; Goldenbaum, F.; Machner, H.

    2009-09-15

    Binary fission induced by 140 MeV {alpha} particles has been measured for {sup nat}Ag, {sup 139}La, {sup 165}Ho, and {sup 197}Au targets. The measured quantities are the total kinetic energies, fragment masses, and fission cross sections. The results are compared with other data and systematics. A minimum of the fission probability in the vicinity Z{sup 2}/A=24 is observed.

  2. Office of Inspector General semiannual report to Congress, April 1--September 30, 1995

    SciTech Connect

    1995-10-01

    This Office of Inspector General Semiannual Report to the Congress covers the period from April 1 through September 30, 1995. The report summarizes significant audit, inspection, and investigative accomplishments for the reporting period, a large portion of which facilitated Department of Energy management efforts to improve management controls and ensure efficient and effective operation of its programs. Narratives of the most significant reports are grouped by six primary performance measures which the Office of Inspector General uses to gauge its attainment of the outcomes established in the Office of Inspector General Strategic Plan. The common thread that ties the performance measures together is their emphasis on supporting Department efforts to produce high quality products at the lowest possible cost to the taxpayer. The six performance measures present outcomes of Office of Inspector General work in terms of improvements in Department programs and operations.

  3. Isotope separation and advanced manufacturing technology. Volume 2, No. 2, Semiannual report, April--September 1993

    SciTech Connect

    Kan, Tehmanu; Carpenter, J.

    1993-12-31

    This is the second issue of a semiannual report for the Isotope Separation and Advanced Manufacturing (ISAM) Technology Program at Lawrence Livermore National Laboratory. Primary objectives of the ISAM Program include: the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) process, and advanced manufacturing technologies which include industrial laser materials processing and new manufacturing technologies for uranium, plutonium, and other strategically important materials in support of DOE and other national applications. Topics included in this issue are: production plant product system conceptual design, development and operation of a solid-state switch for thyratron replacement, high-performance optical components for high average power laser systems, use of diode laser absorption spectroscopy for control of uranium vaporization rates, a two-dimensional time dependent hydrodynamical ion extraction model, and design of a formaldehyde photodissociation process for carbon and oxygen isotope separation.

  4. Synodic and semiannual oscillations of argon-40 in the lunar exosphere

    NASA Astrophysics Data System (ADS)

    Hodges, R. Richard; Mahaffy, Paul R.

    2016-01-01

    The neutral mass spectrometer on the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft collected a trove of exospheric data, including a set of high-quality measurements of radiogenic 40Ar over a period of 142 days. Data synthesis studies, using well-established exosphere simulation tools, show that the LADEE argon data are consistent with an exosphere-regolith interaction that is dominated by adsorption and that the desorption process generates the Armand distribution of exit velocities. The synthesis work has uncovered an apparent semiannual oscillation of argon that is consistent with temporal sequestration in the seasonal cold traps created at the poles by the obliquity of the Moon. In addition, the LADEE data provide new insight into the pristine nature of lunar regolith, its spatially varying sorption properties, and the influence of sorption processes on the synodic oscillation of the argon exosphere.

  5. Automated solar cell assembly teamed process research. Semiannual subcontract report, December 6, 1993--June 30, 1994

    SciTech Connect

    Nowlan, M.

    1995-01-01

    This is the second Semiannual Technical Progress Report for the program titled `Automated Solar Cell Assembly Teamed Process Research` funded under National Renewable Energy Laboratory (NREL) subcontract No. ZAG-3-11219-01. This report describes the work done on Phase II of the program in the period from December 6, 1993 to June 30, 1994. Spire`s objective in this program is to develop high throughput (5 MW/yr) automated processes for interconnecting thin (200 {mu}m) silicon solar cells. High yield will be achieved with these fragile cells through the development of low mechanical stress and low thermal stress processes. For example, a machine vision system is being developed for cell alignment without mechanically contacting the cell edges, while a new soldering process is being developed to solder metal interconnect ribbons simultaneously to a cells` front and back contacts, eliminating one of the two heating steps normally used for soldering each cell.

  6. Semiannual report to Congress on Inspector General audit reports, April 1, 1993--September 30, 1993

    SciTech Connect

    Not Available

    1993-11-01

    This is the Secretary of Energy`s ninth Semiannual Report to Congress to be submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, April 1 through September 30, 1993, the Department took final action on four contract and financial assistance audit reports. At the end of the period only three reports awaited final action. With regard to operational, financial, and preaward audits, final action was taken on 41 reports, resulting in 93 audit reports needing final action at the end of the period.

  7. Fusion reactor materials. Semiannual progress report for period ending September 30, 1993

    SciTech Connect

    Rowcliffe, A.F.; Burn, G.L.; Knee`, S.S.; Dowker, C.L.

    1994-02-01

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide.

  8. Semi-annual report of the Department of Energy, Office of Environmental Management, Quality Assessment Program

    SciTech Connect

    Greenlaw, P.D.; Minick, S.K.

    1998-07-01

    This Quality Assessment Program (QAP) is designed to test the quality of the environmental measurements being reported to the Department of Energy by its contractors. Since 1976, real or synthetic environmental samples that have been prepared and thoroughly analyzed at the Environmental Measurements Laboratory (EML) have been distributed at first quarterly and then semi-annually to these contractors. Their results, which are returned to EML within 90 days, are compiled with EML`s results and are reported back to the participating contractors 30 days later. This report presents the results from the analysis of the 48th set of environmental quality assessment samples (QAP XLVIII) that were received on or before June 1, 1998.

  9. TFE Verification Program: Semiannual report for the period ending September 30, 1987

    SciTech Connect

    Not Available

    1988-03-01

    The objective of the semiannual progress report is to summarize the technical results obtained during the latest reporting period. The information presented herein will include evaluated test data, design evaluations, the results of analyses and the significance of results. The program objective is to demonstrate the technology readiness of a TFE suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full-power life of 7 years. The TFE Verification Program builds directly on the technology and data base developed in the 1960s and early 1970s in an AEC/NASA program, and in the SP-100 program conducted in 1983, 1984 and 1985. In the SP-100 program, the attractive features of thermionic power conversion technology were recognized, but concern was expressed over the lack of fast reactor irradiation data. The TFE Verification Program addresses this concern.

  10. TFE Verification Program: Semiannual report for the period ending October 31, 1988

    SciTech Connect

    Not Available

    1989-01-01

    The objective of the semiannual progress report is to summarize the technical results obtained during the latest reporting period. The information presented herein will include evaluated test data, design evaluations, the results of analyses and the significance of results. The program objective is to demonstrate the technology readiness of a TFE suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full-power life of 7 years. The TFE Verification Program builds directly on the technology and data base developed in the 1960s and early 1970s in an AEC/NASA program, and in the SP-100 program conducted in 1983, 1984 and 1985. In the SP-100 program, the attractive features of thermionic power conversion technology were recognized, but concern was expressed over the lack of fast reactor irradiation data. 65 figs., 36 tabs.

  11. NNWSI waste from testing at Argonne National Laboratory. Semiannual report, July-December 1985

    SciTech Connect

    Bates, J.K.; Gerding, T.J.; Abrajano, T.A. Jr.; Ebert, W.

    1986-03-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) Project is investigating the volcanic tuff beds of Yucca Mountain, Nevada, as a potential location for a high-level radioactive waste repository. As part of the waste package development portion of this project, experiments are being performed by the Chemical Technology Division of Argonne National Laboratory to study the behavior of the waste forms under anticipated repository conditions. These experiments include (1) the development and performance of a test to measure waste form behavior in unsaturated conditions and (2) the performance of tests designed to study the behavior of waste package components in an irradiated environment. Previous reports document developments in these areas through 1984. This report summarizes progress in 1985. Reports will be issued semi-annually hereafter.

  12. Office of Inspector General semiannual report to Congress, October 1, 1997--March 31, 1998

    SciTech Connect

    1998-04-01

    This Office of Inspector General (OIG) Semiannual Report to the Congress covers the period from October 1, 1997, through March 31, 1998. The report summarizes significant audit, inspection, and investigative accomplishments for the reporting period that facilitated Department of Energy (Department) efforts to improve management controls and ensure efficient and effective operation of its programs. This report highlights OIG accomplishments in support of its Strategic Plan. Narratives of the Office`s most significant reports are grouped by the strategic goals against which the OIG measures its performance. To put the OIG accomplishments for this reporting period in context, the following statistical information is provided: audit and inspection reports issued -- 47; recommendations that funds be put to better use -- $356,257,856; management commitment to taking corrective actions -- $289,106,445; criminal indictments/convictions -- 8; fines and recoveries -- $1,612,932; and investigative reports to management recommending positive change -- 21.

  13. NRC regulatory agenda: Semiannual report, January--June 1997. Volume 16, Number 1

    SciTech Connect

    1997-08-01

    The Regulatory Agenda is a semiannual compilation of all rules on which the NRC has recently completed action, or has proposed action, or is considering action, and of all petitions for rulemaking that the NRC has received that are pending disposition. The agenda consists of two sections that have been updated through June 30, 1997. Section 1, ``Rules,`` includes (A) rules on which final action has been taken since December 31, 1996, the closing date of the last NRC Regulatory Agenda; (B) rules published previously as proposed rules on which the Commission has not taken final action; (C) rules published as advance notices of proposed rulemaking for which neither a proposed nor final rule has been issued; and (D) unpublished rules on which the NRC expects to take action. Section 2, ``Petitions for Rulemaking,`` includes (A) petitions denied or incorporated into final rules since December 31, 1996; (B) petitions incorporated into proposed rules; and (C) petitions pending staff review.

  14. Federal Energy Resources Modernization Coordinating Committee. Semiannual Report, October 1, 1991 Through March 31, 1992

    SciTech Connect

    Parker, G B

    1992-07-01

    This report summarizes the broad range of activities supported by Federal Energy Management Program (FEMP) and other federal agencies focused on meeting the President`s Executive Order on Federal Energy Management promulgated to meet energy savings goals and encourage more efficient management of all federal energy resources. These activities are reported semiannually under the auspices of the FERM Coordinating Committee, and as such include activities undertaken from October 1, 1991, through March 31, 1992. The activities reported are classified into four major categories: (1) technology-base support, which includes development of processes, software, metering and monitoring equipment and strategies, and other tools for the federal energy manager to better understand and characterize their energy resources; (2) federal energy systems testing and monitoring; (3) federal energy systems modernization projects at federal installations in cooperation with the utilities serving the sites; and (4) energy supply, distribution and end-use conservation assessment for federal agencies and/or facilities.

  15. Discovery of a 1731-MeV narrow resonance

    NASA Astrophysics Data System (ADS)

    Vladimirsky, V. V.; Grigor'ev, V. K.; Erofeev, I. A.; Erofeeva, O. N.; Zaitsev, A. P.; Katinov, Yu. V.; Lisin, V. I.; Luzin, V. N.; Nozdrachev, V. N.; Sokolovsky, V. V.; Fadeeva, E. A.; Shkurenko, Yu. P.

    2007-10-01

    Results obtained by studying a previously unknown narrow meson of mass about 1731 MeV are presented. This state was found in a system of two K S mesons. The experimental-data set subjected to the present analysis was obtained with a 6-m spectrometer of the Institute of Theoretical and Experimental Physics (ITEP, Moscow). The statistical sample of event of double K S -meson production was accumulated in π- p interactions by using a beam of 40-GeV pions from the U-70 accelerator of the Institute of High Energy Physics (IHEP, Protvino). There are 58 events at the respective maximum, its statistical significance being close to six standard deviations. The parameters of the observed meson are the following; the mass is M = 1731 ± 2.5 MeV, the width is σ = 3.2 ± 2 MeV, and the product of the production cross section and the respective branching ratio is not less than 20 nb. The fact that the observed meson is extremely narrow does not have a satisfactory theoretical explanation.

  16. Femtosecond time-resolved MeV electron diffraction

    SciTech Connect

    Zhu, Pengfei; Zhu, Y.; Hidaka, Y.; Wu, L.; Cao, J.; Berger, H.; Geck, J.; Kraus, R.; Pjerov, S.; Shen, Y.; Tobey, R. I.; Hill, J. P.; Wang, X. J.

    2015-06-02

    We report the experimental demonstration of femtosecond electron diffraction using high-brightness MeV electron beams. High-quality, single-shot electron diffraction patterns for both polycrystalline aluminum and single-crystal 1T-TaS2 are obtained utilizing a 5 fC (~3 × 104 electrons) pulse of electrons at 2.8 MeV. The high quality of the electron diffraction patterns confirms that electron beam has a normalized emittance of ~50 nm rad. The transverse and longitudinal coherence length is ~11 and ~2.5 nm, respectively. The timing jitter between the pump laser and probe electron beam was found to be ~100 fs (rms). The temporal resolution is demonstrated by observing the evolution of Bragg and superlattice peaks of 1T-TaS2 following an 800 nm optical pump and was found to be 130 fs. Lastly, our results demonstrate the advantages of MeV electrons, including large elastic differential scattering cross-section and access to high-order reflections, and the feasibility of ultimately realizing below 10 fs time-resolved electron diffraction.

  17. Femtosecond time-resolved MeV electron diffraction

    DOE PAGES

    Zhu, Pengfei; Zhu, Y.; Hidaka, Y.; Wu, L.; Cao, J.; Berger, H.; Geck, J.; Kraus, R.; Pjerov, S.; Shen, Y.; et al

    2015-06-02

    We report the experimental demonstration of femtosecond electron diffraction using high-brightness MeV electron beams. High-quality, single-shot electron diffraction patterns for both polycrystalline aluminum and single-crystal 1T-TaS2 are obtained utilizing a 5 fC (~3 × 104 electrons) pulse of electrons at 2.8 MeV. The high quality of the electron diffraction patterns confirms that electron beam has a normalized emittance of ~50 nm rad. The transverse and longitudinal coherence length is ~11 and ~2.5 nm, respectively. The timing jitter between the pump laser and probe electron beam was found to be ~100 fs (rms). The temporal resolution is demonstrated by observing themore » evolution of Bragg and superlattice peaks of 1T-TaS2 following an 800 nm optical pump and was found to be 130 fs. Lastly, our results demonstrate the advantages of MeV electrons, including large elastic differential scattering cross-section and access to high-order reflections, and the feasibility of ultimately realizing below 10 fs time-resolved electron diffraction.« less

  18. Annual and semiannual variations of the geomagnetic field at equatorial locations

    USGS Publications Warehouse

    Campbell, W.H.

    1981-01-01

    For a year of quiet solar-activity level, geomagnetic records from American hemisphere observatories located between about 0?? and 30?? north geomagnetic latitude were used to compare the annual and semiannual variations of the geomagnetic field associated with three separate contributions: (a) the quiet-day midnight level, MDT; (b) the solar-quiet daily variation, Sq; (c) the quiet-time lunar semidiurnal tidal variation, L(12). Four Fourier spectral constituents (24, 12, 8, 6 h periods) of Sq were individually treated. All three orthogonal elements (H, D and Z) were included in the study. The MDT changes show a dominant semiannual variation having a range of about 7 gammas in H and a dominant annual variation in Z having a range of over 8 gammas. These changes seem to be a seasonal response to the nightside distortions by magnetospheric currents. There is a slow decrease in MDT amplitudes with increasing latitude. The Sq changes follow the patterns expected from an equatorial ionospheric dynamo electrojet current system. The dominant seasonal variations occur in H having a range of over 21 gammas for the 24 h period and over 12 gammas for the 12 h period spectral components. The higher-order components are relatively smaller in size. The Sq(H) amplitudes decrease rapidly with increasing latitude. Magnetospheric contributions to the equatorial Sq must be less than a few per cent of the observed magnitude. The L(12) variation shows the ionospheric electrojet features by the dominance of H and the rapid decrease in amplitude with latitude away from the equator. However, the seasonal variation range of over 7 gammas has a maximum in early February and minimum in late June that is not presently explainable by the known ionospheric conductivity and tidal behavior. ?? 1981.

  19. MHD Technology Transfer, Integration and Review Committee. Second semiannual status report, July 1988--March 1989

    SciTech Connect

    Not Available

    1989-10-01

    As part of the MHD Integrated Topping Cycle (ITC) project, TRW was given the responsibility to organize, charter and co-chair, with the Department of Energy (DOE), an MHD Technology Transfer, Integration and Review Committee (TTIRC). The Charter of the TTIRC, which was approved by the DOE in June 1988 and distributed to the committee members, is included as part of this Summary. As stated in the Charter, the purpose of this committee is to: (1) review all Proof-of-Concept (POC) projects and schedules in the national MHD program; to assess their compatibility with each other and the first commercial MHD retrofit plant; (2) establish and implement technology transfer formats for users of this technology; (3) identify interfaces, issues, and funding structures directly impacting the success of the commercial retrofit; (4) investigate and identify the manner in which, and by whom, the above should be resolved; and (5) investigate and assess other participation (foreign and domestic) in the US MHD Program. The DOE fiscal year 1989 MHD Program Plan Schedule is included at the end of this Summary. The MHD Technology Transfer, Integration and Review Committee`s activities to date have focused primarily on the ``technology transfer`` aspects of its charter. It has provided a forum for the dissemination of technical and programmatic information among workers in the field of MHD and to the potential end users, the utilities, by holding semi-annual meetings. The committee publishes this semi-annual report, which presents in Sections 2 through 11 capsule summaries of technical progress for all DOE Proof-of-Concept MHD contracts and major test facilities.

  20. Environmental restoration/waste management-applied technology semiannual report, January--June 1992. Volume 1, No. 1

    SciTech Connect

    Adamson, M.; Kline-Simon, K.

    1992-12-31

    This is the first issue from the Lawrence Livermore National Laboratory of The Environmental Restoration/Waste Management-Applied Technology (ER/WM-AT) Semiannual Report, a continuation of the Advanced Processing Technology (APT) Semiannual Report. The name change reflects the consolidation of the APT Program with the Environmental Restoration and Waste Management Program to form the Environmental Restoration/Waste Management-Applied Technology (ER/WM-AT) Program. The Livermore site mirrors, on a small scale, many of the environmental and waste management problems of the DOE Complex. The six articles in this issue cover incineration- alternative technologies, process development for waste minimization, the proposed Mixed Waste Management Facility, dynamic underground stripping, electrical resistance tomography, and Raman spectroscopy for remote characterization of underground tanks.

  1. Annual and semi-annual variability of cloud covering in Abastumani and their coupling with cosmic factors

    NASA Astrophysics Data System (ADS)

    Todua, M.; Didebulidze, G. G.

    2016-09-01

    Investigation of the influence of cosmic factors on the Earths's atmosphere is an important issue of the atmospheric and solar-terrestrial coupling studies. Contribution of cosmic factors to the climate change, included in the solar-terrestrial coupling models, is a matter of increasing interest. We studied long-term inter-annual variations of cloud covering in Abastumani Astrophysical Observatory (N41°45'; E42°49') during day- and night-time, at various helio-geophysical conditions, as well as coupling with cosmic factors. We found that these distributions are different: for cloudless days they reveal semi-annual periodicity, while for cloudless nights both annual and semi-annual ones are observed, depending also on geomagnetic activity. This may be a manifestation of possible influence of cosmic factors on cloud covering.

  2. Cross sections and analyzing powers of sup 15 N(p,n) sup 15 O at 200 MeV and 494 MeV

    SciTech Connect

    Ciskowski, D.E. )

    1989-11-01

    Differential cross sections and analyzing powers have been measured for the {sup 15}N(p,n){sup 15} O(g.s.) reaction at bombarding energies of 200 MeV and 494 MeV. The 494 MeV data were obtained at the LAMPF Neutron Time-Of-Flight Facility on an 82 m flight path with a resolution of about 2.7 MeV. The 200 MeV data were obtained at IUCF on a 76m flight path with a resolution of about 1.1 MeV. At both energies, the measured analyzing power is small, the magnitude is less than .2 for momentum transfers of less than 1 fm{sup {minus}1}. In contrast, both Relativistic and standard DWIA calculations predict a maximum of A={minus}.7 near q=0.7 fm{sup {minus}1}. 53 refs., 44 figs.

  3. Analysis of Satellite sea surface temperature time series in the Brazil-Malvinas Current confluence region: Dominance of the annual and semiannual periods

    NASA Astrophysics Data System (ADS)

    Provost, Christine; Garcia, Omar; GarçOn, VéRonique

    1992-11-01

    We study the dominant periodic variations of sea surface temperature (SST) in the Brazil-Malvinas Confluence region from a satellite-derived data set compiled by Olson et al. (1988). This data set is composed of 202 sea surface temperature images with a 4 × 4 km resolution and extends over 3 years (from July 1984 to July 1987). Each image is a 5-day composite. The dominant signal, as already observed by Podesta et al. (1991), has a 1-year period. We first fit a single-frequency sinusoidal model of the annual cycle in order to estimate mean temperature, amplitude, and phase at 159 points uniformly distributed over the region. The residuals are generally small (less than 2°C). The largest departures from this cycle are located either in the Brazil-Malvinas frontal region or in the southeastern part of the region. Other periods in SST variations are identified by means of periodograms of the 159 residual time series in which the annual cycle has been substracted. The periodograms show that a semiannual frequency signal is present at almost every location. The ratio of the semiannual amplitude to the annual amplitude increases southward from 0% at 30°S to reach up to 45% at 50°S. In the south the semiannual signal creates an asymmetry, and the resulting (total) annual cycle has a cold period (winter) longer than the warm one (summer). In the frontal region the annual and semiannual signals have an important interannual variation. This semiannual frequency is associated with the semiannual wave present in the atmospheric forcing of the southern hemisphere. Differential heating over the mid-latitude oceans and the high-latitude ice-covered Antarctic Continent has been suggested as the cause of this semiannual wave (Van Loon, 1967).

  4. 17O(n,α)14C cross section from 25 meV to approximately 1 MeV

    NASA Astrophysics Data System (ADS)

    Koehler, P. E.; Graff, S. M.

    1991-12-01

    We have measured the 17O(n,α)14C cross section from thermal energy to approximately 1 MeV. A bump in the data near 3 keV could be fitted by a state whose properties are consistent with a known subthreshold J π=1- level at Ex=8.039 MeV. The cause of the 1/v cross section near thermal energy could not be determined although the known 2+ state at 8.213 MeV was found to be too narrow to contribute much to the thermal cross section. Our data are compared to measurements made via the inverse reaction. There are many differences between the two sets of data. The astrophysical reaction rate was calculated from the measured cross section. This reaction plays a role in the nucleosynthesis of heavy elements in nonstandard big-bang models. At big-bang temperatures, the experimental rate was found to be in fair agreement with the rate estimated from the previously known properties of states of 18O in this region. Furthermore, using the available information from experiments, it was estimated that the 17O(n,α)14C rate is approximately a factor of 103-104 times larger than the 17O(n,γ)18O rate at big-bang temperatures. As a result, there may be significant cycling between 14C and 17O resulting in a reduction of heavy-element nucleosynthesis.

  5. MHD Technology Transfer, Integration and Review Committee. Fifth semi-annual status report, April 1990--September 1990

    SciTech Connect

    Not Available

    1992-01-01

    This fifth semi-annual status report of the MHD Technology Transfer, Integration, and Review Committee (TTIRC) summarizes activities of the TTIRC during the period April 1990 through September 1990. It includes summaries and minutes of committee meetings, progress summaries of ongoing Proof-of-Concept (POC) contracts, discussions pertaining to technical integration issues in the POC program, and planned activities for the next six months.

  6. MeV proton flux predictions near Saturn's D ring

    NASA Astrophysics Data System (ADS)

    Kollmann, P.; Roussos, E.; Kotova, A.; Cooper, J. F.; Mitchell, D. G.; Krupp, N.; Paranicas, C.

    2015-10-01

    Radiation belts of MeV protons have been observed just outward of Saturn's main rings. During the final stages of the mission, the Cassini spacecraft will pass through the gap between the main rings and the planet. Based on how the known radiation belts of Saturn are formed, it is expected that MeV protons will be present in this gap and also bounce through the tenuous D ring right outside the gap. At least one model has suggested that the intensity of MeV protons near the planet could be much larger than in the known belts. We model this inner radiation belt using a technique developed earlier to understand Saturn's known radiation belts. We find that the inner belt is very different from the outer belts in the sense that its intensity is limited by the densities of the D ring and Saturn's upper atmosphere, not by radial diffusion and satellite absorption. The atmospheric density is relatively well constrained by EUV occultations. Based on that we predict an intensity in the gap region that is well below that of the known belts. It is more difficult to do the same for the region magnetically connected to the D ring since its density is poorly constrained. We find that the intensity in this region can be comparable to the known belts. Such intensities pose no hazard to the mission since Cassini would only experience these fluxes on timescales of minutes but might affect scientific measurements by decreasing the signal-to-contamination ratio of instruments.

  7. The 14 MeV Frascati neutron generator

    NASA Astrophysics Data System (ADS)

    Martone, M.; Angelone, M.; Pillon, M.

    1994-09-01

    The 14-MeV Frascati neutron generator (FNG) uses the T(d, n)α fusion reaction to produce 5.0 × 10 11 n/s. In FNG a beam of deuterons is accelerated up to 300 keV by means of a linear electrostatic tube and directed onto a tritiated-titanium target containing 37 × 10 10 Bq of tritium. This paper describes the FNG facility and its auxiliary apparatus as well as the neutron source calibration performed using the associated α-particle method.

  8. Stability Study of ATF 80MeV Injector Linac

    SciTech Connect

    McCormick, Douglas

    2003-06-09

    A beam stability test was carried out at ATF 80 MeV injector linac. The test was performed by taking data of each monitor in pulse to pulse base. A data acquisition system which consists of a PC and a GPIB network was used for the test. In order to analyze the data, ''Correlation Plot'' method is used which is effective to find out some source of the observed beam fluctuation. This paper describes the result of the stability measurement and the comparison between ATF injector and SLC injector.

  9. Polarization observables in deuteron photodisintegration below 360 MeV

    SciTech Connect

    Glister, J.; Ron, G.; Lee, B. W.; Gilman, R.; Sarty, A. J.; Strauch, S.; Higinbotham, D. W.; Piasetzky, E.; Allada, K.; Armstrong, W.; Arrington, J.; Arenhövel, H.; Beck, A.; Benmokhtar, F.; Berman, B. L.; Boeglin, W.; Brash, E.; Camsonne, A.; Calarco, J.; Chen, J. P.; Choi, S.; Chudakov, E.; Coman, L.; Craver, B.; Cusanno, F.; Dumas, J.; Dutta, C.; Feuerbach, R.; Freyberger, A.; Frullani, S.; Garibaldi, F.; Hansen, J. -O.; Holmstrom, T.; Hyde, C. E.; Ibrahim, H.; Ilieva, Y.; de Jager, C. W.; Jiang, X.; Jones, M. K.; Kang, Hyekoo; Kelleher, A.; Khrosinkova, E.; Kuchina, E.; Kumbartzki, G.; LeRose, J. J.; Lindgren, R.; Markowitz, P.; May-Tal Beck, S.; McCullough, E.; Meekins, D.; Meziane, M.; Meziani, Z. -E.; Michaels, R.; Moffit, B.; Norum, B. E.; Oh, Y.; Olson, M.; Paolone, M.; Paschke, K.; Perdrisat, C. F.; Potokar, M.; Pomatsalyuk, R.; Pomerantz, I.; Puckett, A.; Punjabi, V.; Qian, X.; Qiang, Y.; Ransome, R. D.; Reyhan, M.; Roche, J.; Rousseau, Y.; Saha, A.; Sawatzky, B.; Schulte, E.; Schwamb, M.; Shabestari, M.; Shahinyan, A.; Shneor, R.; Širca, S.; Slifer, K.; Solvignon, P.; Song, J.; Sparks, R.; Subedi, R.; Urciuoli, G. M.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Zhan, X.; Zhu, X.

    2011-02-03

    We performed high precision measurements of induced and transferred recoil proton polarization in d($\\vec{γ}$, $\\vec{p}$)n for photon energies of 277--357 MeV and θcm = 20 ° -- 120 °. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. Moreover, at the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.

  10. Polarization observables in deuteron photodisintegration below 360 MeV

    DOE PAGES

    Glister, J.; Ron, G.; Lee, B. W.; Gilman, R.; Sarty, A. J.; Strauch, S.; Higinbotham, D. W.; Piasetzky, E.; Allada, K.; Armstrong, W.; et al

    2011-02-03

    We performed high precision measurements of induced and transferred recoil proton polarization in d(more » $$\\vec{γ}$$, $$\\vec{p}$$)n for photon energies of 277--357 MeV and θcm = 20 ° -- 120 °. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. Moreover, at the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.« less

  11. Semiannual report

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, fluid mechanics, and computer science during the period 1 Oct. 1994 - 31 Mar. 1995.

  12. First Light: MeV Astrophysics from the Moon

    NASA Astrophysics Data System (ADS)

    Miller, Richard S.; Lawrence, David J.

    2016-06-01

    We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5–9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

  13. Effects of MeV Ions on PE and PVDC

    SciTech Connect

    Evelyn, A.L.; Ila, D.; Zimmerman, R.L.; Bhat, K.; Poker, D.B.; Hensley, D.K.

    1997-12-31

    We studied the effects of 3.5 and 5.0 MeV alpha bombardment on polyethylene and polyvinylidene chloride both of which have simple chemical structures. Using a thin polymer film stacking technique, we were able to map the effects of the MeV alpha particles in their track. The first layer of the thin polymer film stack experienced most of the effects of the electronic energy deposited and the last layer received most of the effects of the nuclear stopping. Using Raman microprobe analysis and measuring the ratio of the formation of graphene structures (G-line) to the disordered (amorphous) carbon line (D-line), we were able to separate the severed bond effects in the end of the alpha particles` track in the last polymer film layers from the effects of the electronic energy deposited in the first polymer film layers. The results are in agreement with our other measurements of each polymer film using FTIR, RBS and resistance measurements.

  14. MeV Dark Matter and Small Scale Structure

    SciTech Connect

    Hooper, Dan; Kaplinghat, Manoj; Strigari, Louis E.; Zurek, Kathryn M.; /Wisconsin U., Madison

    2007-04-01

    WIMPs with electroweak scale masses (neutralinos, etc.) remain in kinetic equilibrium with other particle species until temperatures approximately in the range of 10 MeV to 1 GeV, leading to the formation of dark matter substructure with masses as small as 10{sup -4} M{sub {circle_dot}} to 10{sup -12} M{sub {circle_dot}}. However, if dark matter consists of particles with MeV scale masses, as motivated by the observation of 511 keV emission from the Galactic Bulge, such particles are naturally expected to remain in kinetic equilibrium with the cosmic neutrino background until considerably later times. This would lead to a strong suppression of small scale structure with masses below about 10{sup 7}M{sub {circle_dot}} to 10{sup 4} M{sub {circle_dot}}. This cutoff scale has important implications for present and future searches for faint Local Group satellite galaxies and for the missing satellites problem.

  15. X-ray FEL with a meV bandwidth

    NASA Astrophysics Data System (ADS)

    Saldin, E. L.; Schneidmiller, E. A.; Shvyd'ko, Yu. V.; Yurkov, M. V.

    2001-12-01

    A new design for a single pass X-ray Self-Amplified Spontaneous Emission (SASE) FEL was proposed by Feldhaus et al. (Opt. Commun. 140 (1997) 341) and named "two-stage SASE FEL". The scheme consists of two undulators and an X-ray monochromator located between them. For the Angström wavelength range the monochromator can be realized using Bragg reflections from crystals. We propose a scheme of monochromator with a bandwidth of 20 meV for the 14.4 keV X-ray SASE FEL being developed in the framework of the TESLA linear collider project. The spectral bandwidth of the radiation from the two-stage SASE FEL (20 meV) is determined by the finite duration of the electron pulse. The shot-to-shot fluctuations of energy spectral density are dramatically reduced in comparison with the 100% fluctuations in a SASE FEL. The peak and average brilliance are three orders of magnitude higher than the values which could be reached by a conventional X-ray SASE FEL.

  16. Annual and semi-annual variability in the lower and upper atmosphere-ionosphere coupling processes by observations from Abastumani (41.75 N, 42.82 E)

    NASA Astrophysics Data System (ADS)

    Didebulidze, G. G.; Todua, M.; Javakhishvili, G.

    2015-12-01

    The importance of annual and semi-annual variability in the long-term variations of the ionosphere F2 layer parameters (NmF2, hmF2), the hydroxyl OH bands, the oxygen green 557.7 nm and red 630.0 line intensities observed from Abastumani is noted. The amplitudes of the semi-annual variations of these upper atmosphere-ionosphere parameters with maxima at equinoctial months depend on the value of the planetary geomagnetic Ap index, also observed in the inter-annual distribution of the total ozone content (TOC) and cloud covering over this region of South Caucasus. The observed dependence of semi-annual variations of these parameters on Ap index indicated possible influence of cosmic factors on the lower and upper atmosphere-ionosphere coupling processes.

  17. Semi-annual technical report, September 30, 1999 - March 31, 2000

    SciTech Connect

    Schumacher, Dorin

    2000-04-01

    The Consortium for Plant Biotechnology Research, Inc. (CPBR) continues to operate according to objectives outlined in the proposal funded through the cooperative agreement. The italicized objectives below are addressed in this report, which covers the period September 30,1999 through March 31, 2000. (1) Update the research agenda using information obtained from member companies. (2) Identify and implement research projects that are deemed by industrial, scientific, and sponsoring agency evaluation to address significantly the problems and future of U.S. energy resources and that are relevant to the Department of Energy's mission. Specifically: (1) Announce research grants competition through a Request for Preproposals. (2) Conduct a dual-stage review process: Stage one--industrial and DOE review of preproposals; and Stage two--peer review, scientific consultants' review, DOE review of full proposals and Project Recommendation Committee evaluation and recommendation for funding. (3) Board of Directors approval of recommended awards. (4) Conduct ongoing project management. (5) Obtain semiannual, annual and final reports for evaluation of research goals and technology transfer. (6) Present reports to DOE.

  18. Fusion materials semiannual progress report for the period ending December 31, 1997

    SciTech Connect

    Burn, G.

    1998-03-01

    This is the twenty-third in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Materials Program is a national effort involving several national laboratories, universities, and industries. A large fraction of this work, particularly in relation to fission reactor experiments, is carried out collaboratively with their partners in Japan, Russia, and the European Union. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  19. Semiannual report to Congress on Inspector General Audit Reports, October 1, 1994--March 31, 1995

    SciTech Connect

    1995-05-01

    This is the Secretary of Energy`s twelfth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, October 1, 1994 through March 31, 1995, the Department took final action on 32 operational, financial, and preaward audit reports. At the end of the period 90 reports awaited final action. Final action was taken on four contract and financial assistance audits, leaving four reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of these reports.

  20. Fusion reactor materials semiannual progress report for the period ending March 31, 1991

    SciTech Connect

    none,

    1991-07-01

    This is the tenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: alloy development for irradiation performance; damage analysis and fundamental studies; special purpose materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials program being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of program participants, and to provide a means of communicating the efforts of materials scientists to the test of the fusion community, both nationally and worldwide.

  1. Semiannual report to Congress on Inspector General audit reports: April 1--September 30, 1997

    SciTech Connect

    1997-11-01

    This is the Secretary of Energy`s seventeenth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, April 1 through September 30, 1997, the Department took final action on 29 operational, financial, and preaward audit reports. At the end of the period 72 reports awaited final action. Final action was taken on five contract and financial assistance audits, leaving two reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of those reports.

  2. Semiannual report to Congress on Inspector General audit reports, October 1, 1997--March 31, 1998

    SciTech Connect

    1998-05-01

    This is the Secretary of Energy`s eighteenth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, October 1, 1997, through March 31, 1998, the Department took final action on 20 operational, financial, and preaward audit reports. At the end of the period 80 reports awaited final action. Final action was taken on one contract and financial assistance audit, leaving two reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of those reports.

  3. Semiannual report to Congress on Inspector General audit reports, October 1, 1996--March 31, 1997

    SciTech Connect

    1997-05-01

    This is the Secretary of Energy`s sixteenth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, October 1, 1996, through March 31, 1997, the Department took final action on 31 operational, financial, and preaward audit reports. At the end of the period 74 reports awaited final action. Final action was taken on 11 contract and financial assistance audits, leaving no reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of those reports.

  4. Fusion materials semiannual progress report for the period ending December 31, 1996

    SciTech Connect

    1997-04-01

    This is the twenty-first in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The report covers the following topics: vanadium alloys; silicon carbide composite materials; ferritic/martensitic steels; copper alloys and high heat flux materials; austenitic stainless steels; insulating ceramics and optical materials; solid breeding materials; radiation effects, mechanistic studies and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; and irradiation facilities, test matrices, and experimental methods.

  5. Preparing for a Semiannual IACUC Inspection of a Satellite Zebrafish (Danio rerio) Facility

    PubMed Central

    Koerber, Amy S; Kalishman, Jennifer

    2009-01-01

    Institutions worldwide have experienced a rapid growth in the use of zebrafish as a research model for a variety of molecular and genetic studies of vertebrate development. This expansion in zebrafish research essentially has outpaced the establishment of specific recommendations for the care and use of fish in research. In some cases, this situation has created a dilemma where an Institutional Animal Care and Use Committee, which is responsible for oversight of vertebrate animal research, is not fully prepared to undertake this role for a decentralized zebrafish facility. IACUC inspectors will be more equipped to ask pertinent questions by understanding the basic principles of zebrafish health and facility management. Concurrently, zebrafish facility managers can contribute to the progress of a semiannual facility inspection by maintaining fully accessible operating records. In the context of presenting a well-established and useful model of zebrafish management and recordkeeping to the zebrafish facility operator, the information we present here also prepares a potential IACUC inspector to conduct a constructive and positive inspection. PMID:19245754

  6. TFE Verification Program semiannual report for the period ending March 31, 1990

    SciTech Connect

    Not Available

    1990-07-01

    The objective of the semiannual progress report is to summarize the technical results obtained during the latest reporting period. The information presented herein will include evaluated test data, design evaluations, the results of analyses and the significance of results. The program objective is to demonstrate the technology readiness of a TFE suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW(e) range, and a full-power life of 7 years. The TFE Verification Program builds directly on the technology and data base developed in the 1960s and early 1970s in an AEC/NASA program, and in the SP-100 program conducted in 1983, 1984 and 1985. In the SP-100 program, the attractive features of thermionic power conversion technology were recognized but concern was expressed over the lack of fast reactor irradiation data. The TFE Verification Program addresses this concern. 6 refs., 67 figs., 37 tabs.

  7. Fusion materials semiannual progress report for the period ending March 31, 1995

    SciTech Connect

    1995-07-01

    This is the eighteenth in a series of semiannual technical progress reports on fusion materials. This report combines research and development activities which were previously reported separately in the following progress reports: {sm_bullet} Alloy Development for Irradiation Performance. {sm_bullet} Damage Analysis and Fundamental Studies. {sm_bullet} Special Purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide. This report has been compiled and edited under the guidance of A.F. Rowcliffe by Gabrielle Burn, Oak Ridge National Laboratory. Their efforts, and the efforts of the many persons who made technical contributions, are gratefully acknowledged.

  8. Fusion reactor materials semiannual progress report for the period ending September 30, 1989

    SciTech Connect

    none,

    1989-01-01

    This is the seventh in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following technical progress reports: alloy development for irradiation performance, damage analysis and fundamental studies, and special purpose materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials program being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide.

  9. Fusion reactor materials: Semiannual progress report for period ending September 30, 1987

    SciTech Connect

    none,

    1988-03-01

    This is the third in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following technical progress reports: Alloy Development for Irradiation Performances; Damage Analysis and Fundamental Studies; Special Purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials program being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide.

  10. Fusion reactor materials semiannual progress report for period ending September 30, 1990

    SciTech Connect

    Not Available

    1991-04-01

    This is the ninth in series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following technical progress reports: Alloy Development of Irradiation Performance; Damage Analysis and Fundamental Studies; and Special Purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials program being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide.

  11. Fusion Reactor Materials semiannual progress report for the period ending March 31, 1992

    SciTech Connect

    Not Available

    1992-07-01

    This is the twelfth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; and Special Purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the US Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide.

  12. Semiannual report to Congress on Inspector General audit reports: October 1, 1995--March 31, 1996

    SciTech Connect

    1996-05-01

    This is the Secretary of Energy`s fourteenth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, October 1, 1995, through March 31, 1996, the Department took final action on 35 operational, financial, and preaward audit reports. At the end of the period 92 reports awaited final action. Final action was taken on two contract and financial assistance audits, leaving two reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of these reports.

  13. Semiannual report to Congress on Inspector General audit reports, April 1, 1995--September 30, 1995

    SciTech Connect

    1995-11-01

    This is the Secretary of Energy`s thirteenth Semiannual Report to Congress submitted under the Inspector General Act of 1978, as amended. Pursuant to the Inspector General Act Amendments of 1988 (Public Law 100-504), agency heads are to report to Congress on the status of final action taken on audit report recommendations. This report complements a report prepared by the Department`s Office of Inspector General that provides information on audit reports issued during the period and on the status of management decisions made on Inspector General audit reports. During the period covered by this report, April 1, 1995, through September 30, 1995, the Department took final action on 33 operational, financial, and preaward audit reports. At the end of the period 96 reports awaited final action. Final action was taken on 2 contract and financial assistance audits, leaving 2 reports requiring final action at the end of the period. This report has three sections. The first section outlines significant audit resolution and followup accomplishments achieved by the Department during the reporting period. The second section contains the statistical tables that illustrate the status of final action on Inspector General audit reports. The third lists the audit reports that are one year or more past management decision and have not completed final action. This section also provides the status of corrective actions on each of these reports.

  14. Office of Inspector General semiannual report to Congress, April 1--September 30, 1998

    SciTech Connect

    1998-10-01

    This Semiannual Report to Congress covers the period April 1 to September 30, 1998. The report summarizes significant Office of Inspector General (OIG) audit, inspection, and investigative accomplishments for the reporting period.These OIG efforts facilitated Department of Energy (DOE) efforts to improve the overall management of its programs. The OIG has developed a Strategic Plan which sets out its overall goals and objectives. The Office`s significant accomplishments are grouped by the strategic goals against which the OIG measures its performance. Highlights are presented on the following items: prime contractor fees policy strengthening; low-level and low-level mixed waste management program improvement; hazardous waste training agreement cost $6 million more than necessary; controls over architect-engineering costs improvement; funds expended contrary to Congressional direction and internal budget execution guidelines; company mischarges costs on several federal contracts; year 2000 computer issues; Qui Tam investigations; task force investigations; financial assistance grantees; DOE suspect/counterfeit items information trending and analysis; and management information systems.

  15. Interaction of the quasi-biennial oscillation and stratopause semiannual oscillation

    NASA Astrophysics Data System (ADS)

    Dunkerton, Timothy J.; Delisi, Donald P.

    1997-11-01

    Analysis of rawinsonde and rocketsonde data at Ascension Island (7.6°S, 14.4°W) and Kwajalein (8.7°N, 167°E) in 1962-1991 suggests that the quasi-biennial oscillation (QBO) in the middle stratosphere is synchronized with the seasonal cycle and that descending westerly phases of the stratopause semiannual oscillation (SAO) are strongly influenced by the underlying QBO. The effect of the seasonal cycle on the QBO in the middle stratosphere is revealed in two, perhaps unrelated, observations: first, a tendency for deseasonalized QBO westerly maxima to occur in local winter (or to avoid local summer); second, a smooth, uninterrupted connection between descending SAO westerly shear zones and the formation of a new QBO westerly shear zone aloft. The timing of deseasonalized QBO westerly maxima in the middle stratosphere allows a simple composite of 2- and 3-year cycles to be constructed from the data, illustrating the effect of the QBO on descending westerly phases of the stratopause SAO.

  16. Two charmoniumlike charged axial resonances near 3885 MeV

    NASA Astrophysics Data System (ADS)

    Voloshin, M. B.

    2016-10-01

    It is argued that the charged Zc+(3885 ) resonance, treated as a "molecular" state of charmed D and D* mesons, is likely to consist of two peaks unequally coupled to the D*+D¯0 and D+D¯*0 channels. The peaks should be split in mass by at least approximately 1.5 MeV. This behavior arises from an enhancement of the effect of isospin violation in the masses of the D and D* mesons due to apparent suppression of forces between the mesons depending on the spins of the heavy as well as the light quarks. The suggested double-peak structure can be studied either by direct shape measurement in the channels with heavy mesons, or by isospin-violating transitions from Zc±(3885 ) to the states of charmonium plus a light meson.

  17. The 50 MeV Beam Test Facility at LBL

    SciTech Connect

    Leemans, W.; Behrsing, G.; Kim, K.J.; Krupnick, J.; Matuk, C.; Selph, F.; Chattopadhyay, S.

    1993-05-01

    A new beam line, expected to be built by September 1993, will transport the 50 MeV electron beam from the ALS LINAC into an experimental area to support various R&D activities in the Center for Beam Physics at LBL. A variety of experiments are planned involving the interaction of such a relativistic electron beam with plasmas (plasma focusing), laser beams (generation of femtosecond X-ray pulses) and electromagnetic cavities (Crab cavities etc....). The beam line is designed using the measured emittance and Twiss parameters of the ALS linac. It accommodates the different requirements of the various experiments on the electron beam properties (charge, energy, pulse length) and on the handling of the beam before and after the interaction point. Special attention has also been given to incorporate diagnostics for measuring the beam properties (such as the electron energy, bunch length and charge) needed in the interpretation of the experiments.

  18. Detectors for energies less than 10 MeV

    NASA Technical Reports Server (NTRS)

    1981-01-01

    In the energy domain 100 keV to 10 MeV, both crystal scintillations and semiconductors are widely used for gamma ray detectors in spectrometer systems. These detectors' operation depend on the fact that gamma rays lose energy by ionization in these materials and electrons and holes are produced. In the case of semiconductors, these electrons and holes are collected by an electric field, and they provide an electric signal that is a direct measure of the energy lost by the gamma ray in the material. Scintillation detectors depend on a further conversion of the energy lost in electron hole pair production to the production of photons. A photomultiplier tube measures the intensity of the photon flux, and an electrical pulse proportional to the photon intensity is produced at the photomultiplier output.

  19. Little Boy neutron spectrum below 3 MeV

    SciTech Connect

    Evans, A.E.; Bennett, E.F.; Yule, T.J.

    1984-01-01

    The leakage neutron spectrum from the Little Boy replica has been measured from 12 keV to 3 MeV using a high-resolution /sup 3/He ionization chamber, and from 1 keV to 3 MeV using proton-recoil proportional counters. The /sup 3/He-spectrometer measurements were made at distances of 0.75 and 2.0 m from the active center and at angles of 0/sup 0/, 45/sup 0/, and 90/sup 0/ with respect to the axis of the assembly. Proton-recoil measurments were made at 90/sup 0/ to the assembly axis at distances of 0.75 and 2.0 m, with a shielded measurement made at 2.0 m to estimate background due to scattering. The /sup 3/He spectrometer was calibrated at Los Alamos using monoenergetic /sup 7/Li(p,n)/sup 7/Be neutrons to generate a family of response functions. The proton-recoil counters were calibrated at Argonne by studying the capture of thermal neutrons by nitrogen in the counters, by observation of the 24-keV neutron resonance in iron, and by relating to the known hydrogen content of the counters. The neutron spectrum from Little Boy was found to be highly structured, with peaks corresponding to minima in the iron total neutron cross section. In particular, influence of the 24-keV iron window was evident in both sets of spectra. The measurements provide information for dosimetry calculations and also a valuable intercomparison of neutron spectrometry using the two different detector types. Spectra measured with both detectors are in essential agreement. 8 references, 7 figures, 2 tables.

  20. Shielding measurements for a 230 MeV proton beam

    SciTech Connect

    Siebers, J.V.

    1990-01-01

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0{degree}, 22{degree}, 45{degree}, and 90{degree} in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm{sup 3} to 1000 cm{sup 3} were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0{degree}, 22{degree}, and 45{degree}, yet correctly predicted the attenuation length at 90{degree}. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations.

  1. Pion Induced Pion Production on Oxygen at 280 Mev.

    NASA Astrophysics Data System (ADS)

    Rozon, Francis Martin

    A first coincident measurement of the pion induced pion production reaction cross-section on a complex nucleus (A > 2) has been successfully performed. In particular, the reaction ^{16}O( pi^+,pi^+pi^-) was measured at 280 MeV incident pion energy. The only previous published measures of this reaction on nuclei consisted of a dated measurement done on emulsion nuclei (BBD*69) and did not provide very stringent limits to the nuclear cross section. Single arm experiments have previously been done elsewhere on the proton (BJK*80) and the deuteron (PGM*84). The reaction was measured at TRIUMF using the QQD magnetic spectrometer in coincidence with the CARUZ (RGR88), a total absorption scintillator range telescope. The measured four-fold differential cross sections were extrapolated to the unmeasured portions of the phase-space to extract the total reaction cross-section at 280 MeV, which was found to be sigma_{tot} = 2.250 +/-.350mb . The (pi,2pi ) cross-section is thus observed to provide approximately 40% of the inclusive double charge exchange cross section (Woo84) at this energy. The model of (OV86) is found to explain many of the features of the data, including sigma _{tot}. The present data do not preclude effects due to pion condensate precursor phenomena as proposed by (CE83) but they do not support the existence of a strong effect. The data are also compared to kinematical Monte Carlo simulations of some possible reaction mechanisms and it is found that the presence of an intermediate Delta can aid the explanation of the low energy features of the pi^+ energy spectrum.

  2. Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations

    SciTech Connect

    Goosman, D.R.

    1984-08-14

    The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table.

  3. MHD Technology Transfer, Integration and Review Committee. Seventh semi-annual status report, April 1991--September 1991

    SciTech Connect

    Not Available

    1993-02-01

    This seventh semi-annual status report of the MHD Technology Transfer, Integration and Review Committee (TTIRC) summarizes activities of the TTIRC during the period April 1991 through September 1991. It includes a summary and minutes of the General Committee meeting, progress summaries of ongoing POC contracts, discussions pertaining to technical integration issues in the POC program, and planned activities for the next six months. The meeting included test plan with Western coal, seed regeneration economics, power management for the integrated topping cycle and status of the Clean Coal Technology Proposal activities. Appendices cover CDIF operations HRSR development, CFFF operations etc.

  4. A comparative study of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiated Si NPN BJTs

    SciTech Connect

    Kumar, M. Vinay Krishnaveni, S.; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani

    2015-06-24

    The impact of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  5. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    NASA Astrophysics Data System (ADS)

    Kumar, M. Vinay; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani, Krishnaveni, S.

    2015-06-01

    The impact of 30MeV boron4+ and 60MeV oxygen8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  6. Effect of 1.33 Mev gamma radiation and 0.5 Mev electrons on the mechanical properties of graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Fornes, R. E.; Memory, J. D.; Naranong, N.

    1982-01-01

    Epoxy/graphite fiber, polyimide/graphite fiber, and polysulfone/graphite fiber composites were exposed to 1.33 Mev gamma irradiation and 0.5 Mev electron bombardment for varying periods of time. The effects of the irradiation treatments on the breaking stress and Young's modulus were studied by a three point bending test. Effects were small; both electron radiation up to 5000 Mrad and gamma radiation up to 350 Mrad resulted in slight increases in both stress and modulus.

  7. Semi-Annual Report to Congress: April 1, 1983-September 30, 1983; No. 7. (Submitted pursuant to Public Law 95-452).

    ERIC Educational Resources Information Center

    Office of Inspector General (ED), Washington, DC.

    This semiannual report of the Department of Education's Office of Inspector General summarizes the office's activities in auditing and investigating abuses in the use of federal monies in education and in improving the management of federally funded programs. The audits for a 6-month period ending September 30, 1983, are graphed and significant…

  8. Semi-Annual Report to Congress: April 1, 1984-September 30, 1984. No. 9. (Submitted Pursuant to Public Law 95-452).

    ERIC Educational Resources Information Center

    Office of Inspector General (ED), Washington, DC.

    This ninth semiannual report issued by the United States Department of Education's Office of Inspector General (OIG) summarizes the activities and accomplishments of that office during a 6-month period ending September 30, 1984. A condensation of audits of Department of Education aid programs presents statistics on OIG activities and the…

  9. Advanced Processing Technology semiannual report, March--December 1991. Volume 1, Number 1

    SciTech Connect

    Adamson, M.; Kline-Simon, K.

    1991-12-31

    This first issue of the APT Semiannual Report focuses on APT`s defense-related technologies. These technologies are a continuation of the research, development, and engineering work performed by LLNLs Special Isotope Separation (SIS) Program. SIS was the first large-scale DOE venture that had environmentally conscious manufacturing processes and facilities as its deliverables. The objectives were to create a facility where the only outputs were either usable products or disposable wastes, and to comply with existing and anticipated federal, state, and local regulations related to safeguards, security, health and safety. To meet these objectives, revolutionary changes were needed in plutonium processing operations, chemistry, and equipment. New processes had to be developed that enhanced worker safety, minimized operator radiation dose, minimized waste at the point of generation, and provided for built-in recycling of residues. The SIS Program developed and demonstrated the technology (both chemistry and physics) necessary to provide plutonium with individual isotopic tailoring. This process made it possible to transform fuel-grade plutonium into weapon-grade material. However, due to the changing world political climate, the country`s need for plutonium to make new weapons has decreased dramatically. As a result, the planned SIS plutonium-separation plant will not be built. After the SIS Program was canceled in 199 1, Congress directed that the plutonium processing technologies under development for the SIS Program be redirected to the weapons program. APT took over the development of the innovative SIS technologies and is applying them to the development of a new, reconfigured Nuclear Weapons Complex -- Complex 21. ``Close Out of the SIS Program`` describes the completion of the SIS research and development work, and the transfer of key technologies to support this reconfiguration effort.

  10. Modality of semiannual to multidecadal oscillations in global sea surface temperature variability

    NASA Astrophysics Data System (ADS)

    Chen, Ge; Shao, Baomin; Han, Yong; Ma, Jun; Chapron, Bertrand

    2010-03-01

    Repeating the history of study on El Niño-Southern Oscillation (ENSO) in the 1980s, interdecadal oscillation (IDO) in climate variability is currently an area of active research and debate, following the recognition of its emerging significance in nature and science. In this work, a two-dimensional propagating modal extraction technique is applied to a reconstructed global monthly sea surface temperature (SST) data set spanning 1854 through 2007, to examine the spatiotemporal structure of SST variability with an emphasis on the fine modal pattern of IDOs. In the time domain, it is revealed that a canonical modal spectrum of decadal-to-centennial SST variability constitutes four most distinct oscillations with periodicities at 9.0, 13.0, 21.2, and 62.2 years, which are naturally defined as primary modes and are, respectively, termed as the subdecadal mode, the quasidecadal mode, the interdecadal mode, and the multidecadal mode (modes S, Q, I, and M). They join the energetic annual mode (mode A) and two major ENSO modes at 3.7 and 5.8 years (modes B and C), as well as a dozen of secondary modes ranging from semiannual to multidecadal, in determining the key pattern of SST-related climate variability. In the space domain, seven modally dynamic areas, analogous to the Niño regions for ENSO, are clearly identified and are named as IDO zones. Contrary to ENSO, dominant IDO zones are most visible in the extratropical oceans, especially in the North Atlantic/North Pacific sectors, while secondary signatures are observed in the tropical oceans. The array of (four) primary modes with respect to (seven) major zones yields a sophisticated yet canonical pattern of IDOs, leading to a basic conclusion that multimodality (for a given region) and multiregionality (for a given mode) are fundamental features of the IDO system.

  11. Little Boy neutron spectrum below 1 MeV

    SciTech Connect

    Evans, A.E.

    1984-01-01

    A high-resolution /sup 3/He ionization chamber of the type development by Cuttler and Shalev was used to study the neutron spectrum from the Little Boy mockup. Measurements were made at distances of 0.75 and 2.0 m and at angles of 0/sup 0/, 45/sup 0/, and 90/sup 0/ with respect to the axis of the assembly, which was operated at power levels from 8.6 to 450 mW. Detector efficiency as a function of energy as well as parameters for correction of pulse-height distributions for proton-recoil and wall effects were determined from a set of response functions for monoenergetic neutrons measured at the Los Alamos 3.75-MeV Van de Graaff Accelerator Facility. Pulse-shape discrimination was used to separate /sup 3/He-recoil pulses from the pulse-height distribution. The spectrum was found to be highly structured, with peaks corresponding to minima in the total neutron cross section of iron. In particular, 15% of the neutrons above the epithermal peak in energy were found to be in the 24-keV iron window. Lesser peaks out to 700 keV are also attributable to filtering action of the weapon's heavy iron casing. Data taken using experimental proton-recoil proportional counters are compared with the high-resolution spectra.

  12. Multipurpose 5-MeV linear induction accelerator

    NASA Astrophysics Data System (ADS)

    Birx, D. L.; Hawkins, S. A.; Poor, S. E.; Reginato, L. L.; Smith, M. W.

    1984-06-01

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, new technology was used to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The magnetic drive system are tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  13. Multipurpose 5-MeV linear induction accelerator

    SciTech Connect

    Birx, D.L.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L. Smith, M.W.

    1984-06-11

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, the researchers used new technology to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The paper describes the scheme. The magnetic drive system can be tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  14. 400 MeV upgrade for the Fermilab linac

    SciTech Connect

    MacLachlan, J.A.

    1989-03-24

    Fermilab has plans for a comprehensive accelerator upgrade to open new possibilities for both the fixed target and collider experimental programs. An early step in this program is to increase the energy of the linac from 200 to 400 MeV by replacing the last four of its nine 201 MHz Alvarez tanks with twenty-eight 805 MHz side-coupled cavity chains operating at about 8 MV/m average axial field. The principal purpose is to reduce the incoherent spacecharge tuneshift at injection into the Booster which currently limits both the brightness of the beam, an important determinant of collider luminosity, and total intensity to produce both the antiprotons for the collider and the beams to fixed target experimental areas. Other consequences of higher Booster injection energy expected to contribute to some degree of higher intensity limits and improved operational characteristics include improved quality of the guide field at injection, reduced frequency swing for the rf systems, and smaller emittance for the injected beam. The linac upgrade project has moved from a 1986 study through a development project including structure models and numerical studies to a full-feature module prototyping starting this year.

  15. 2 MeV linear accelerator for industrial applications

    NASA Astrophysics Data System (ADS)

    Smith, Richard R.; Farrell, Sherman R.

    1997-02-01

    RPC Industries has developed a high average power scanned electron beam linac system for medium energy industrial processing, such as in-line sterilization. The parameters are: electron energy 2 MeV; average beam current 5.0 mA; and scanned width 0.5 meters. The control system features data logging and a Man-Machine Interface system. The accelerator is vertically mounted, the system height above the floor is 3.4 m, and the footprint is 0.9×1.2 meter2. The typical processing cell inside dimensions are 3.0 m by 3.5 m by 4.2 m high with concrete side walls 0.5 m thick above ground level. The equal exit depth dose is 0.73 gm cm-2. Additional topics that will be reported are: throughput, measurements of dose vs depth, dose uniformity across the web, and beam power by calorimeter and magnetic deflection of the beam.

  16. X-ray FEL with a meV bandwidth

    NASA Astrophysics Data System (ADS)

    Saldin, E. L.; Schneidmiller, E. A.; Shvyd'ko, Yu. V.; Yurkov, M. V.

    2001-08-01

    A new design for a single pass X-ray Self-Amplified Spontaneous Emission (SASE) FEL was proposed in [1] and named two-stage SASE FEL. The scheme consists of two undulators and an X-ray monochromator located between them. For the Angström wavelength range the monochromator could be realized using Bragg reflections from crystals. Proposed scheme of monochromator is illustrated for the 14.4 keV X-ray SASE FEL being developed in the framework of the TESLA linear collider project. The spectral bandwidth of the radiation from the two-stage SASE FEL (20 meV) is defined by the finite duration of the electron pulse. The shot-to-shot fluctuations of energy spectral density are dramatically reduced in comparison with the 100% fluctuations in a SASE FEL. The peak and average brilliance are by three orders of magnitude higher than the values which could be reached by a conventional X-ray SASE FEL.

  17. MERLIN - A meV Resolution Beamline at the ALS

    SciTech Connect

    Reininger, Ruben; Bozek, John; Chuang, Y.-D.; Howells, Malcolm; Kelez, Nicholas; Prestemon, Soren; Marks, Steve; Warwick, Tony; Hussain, Zahid; Jozwiak, Chris; Lanzara, Alessandra; Hasan, M. Zahid

    2007-01-19

    An ultra-high resolution beamline is being constructed at the Advanced Light Source (ALS) for the study of low energy excitations in strongly correlated systems with the use of high-resolution inelastic scattering and angle-resolved photoemission. This new beamline, given the acronym Merlin (for meV resolution line), will cover the energy range 10-150 eV. The monochromator has fixed entrance and exit slits and a plane mirror that can illuminate a spherical grating at the required angle of incidence (as in the SX-700 mechanism). The monochromator can be operated in two different modes. In the highest resolution mode, the energy scanning requires translating the monochromator chamber (total travel 1.1 m) as well as rotating the grating and the plane mirror in front of the grating. The resolution in this mode is practically determined by the slits width. In the second mode, the scanning requires rotating the grating and the plane mirror. This mode can be used to scan a few eV without a significant resolution loss. The source for the beamline is a 1.9 m long, 90 mm period quasi periodic EPU. The expected flux at the sample is higher than 1011 photons/s at a resolving power of 5 x 104 in the energy range 16-130 eV. A second set of gratings can be used to obtain higher flux at the expense of resolution.

  18. Emittance measurements in Grumman 1 MeV beamline

    SciTech Connect

    Debiak, T.; Gammel, G.; Melnychuk, S.

    1992-12-01

    The emittance of a 30 keV H{sup {minus}} beam has been measured with an Allison type electrostatic analyser at two positions separated by 85 cm along the Grumman 1 MeV beamline LEBT at low currents (about 4 mA, no Cs{sub 2}O additive in the source) and at higher currents (10-15 mA, with Cs{sub 2}O additive in the source). No emittance growth was observed between the two positions, but, at the higher current level, the emittance was about 60% higher than at the low current level ({Sigma}{sub n},rms = .0045 {pi} cm-mrad vs. 0070 {pi} cm-mrad). Argon was then introduced up to a partial pressure of 4x10{sup {minus}5} torr, and the emittance decreased back to a range corresponding to that found at the lower currents. However, beam noise was observed at the downstream position, and there is evidence for a small amount of emittance growth (<20%) between the two positions.

  19. ETFE polymer bombarded with 1 MeV proton

    NASA Astrophysics Data System (ADS)

    Parada, M. A.; de Almeida, A.; Muntele, I.; Muntele, C.; Delalez, N.; Ila, D.

    2005-12-01

    The ethylenetetrafluoroethylene (ETFE) is a polymer formed by alternating ethylene and tetrafluoroethylene segments. It has high impact resistance and useful mechanical properties. ETFE can be used as components of pumps, valves, tie wraps, and electrical components. It can also be applied in the field of medical physics as intra venous catheters and as radiation dosimeter. When a material is exposed to the ionizing radiation, it suffers damage that depends on the type, energy and intensity of the radiation. In order to determine the radiation damage mechanism, ETFE films were bombarded with 1 MeV protons to the fluence between 1 × 1011 and 1 × 1016 protons/cm2 and the chemical species emitted during the bombardment were measured with residual gas analysis (RGA) and show that HF gas is the entity preferentially emitted. Optical absorption photospectrometry (OAP) and attenuated total reflectometry fourier transform infrared (ATR-FTIR) shows quantitative chemical evidence of the damage. Our results show that damage is detectable at low proton fluence, but damage that can compromise the application in dosimetry occurs only for fluence greater than 1014 protons/cm2.

  20. Energy-efficiency testing activities of the Mobile Energy Laboratory - Semiannual Report: April 1, 1990, Through September 30, 1990

    SciTech Connect

    Parker, G.B.; Currie, J.W.

    1991-03-01

    This report summarizes energy-efficiency testing activities applying the Mobile Energy Laboratory (MEL) testing capabilities during the third and fourth quarters of fiscal year (FY) 1990. The MELs, developed by the US Department of Energy (DOE) Federal Energy Management Program (FEMP), are administered by Pacific Northwest Laboratory (PNL) and the Naval Energy and Environmental Support Activity (NEESA) for energy testing and energy conservation program support functions at federal facilities. MELs are equipped for the on-site evaluation of energy use efficiency. The using agencies principally fund MEL applications, while DOE/FEMP funds program administration and capability enhancement activities. This report fulfills the requirements established in Section 8 of the MEL Use Plan (PNL-6861) for semiannual reporting on energy-efficiency testing activities using the MEL capabilities. The MEL Use Committee, formally established in 1989, developed the MEL Use Plan and meets semiannually to establish priorities for energy-efficient testing applications using the MEL capabilities. This report describes the testing, test results, and suggested courses of action.

  1. Elastic scattering of polarised deuterons from 16O at 200, 400 and 700 MeV

    NASA Astrophysics Data System (ADS)

    van Sen, Nguyen; Yanlin, Ye; Arvieux, J.; Gaillard, G.; Bonin, B.; Boudard, A.; Bruge, G.; Lugol, J. C.; Hasegawa, T.; Soga, F.; Antonuk, L. E.; Cameron, J. M.; Lam, S. T.; Neilson, G. C.; Roy, G.; Sheppard, D. M.; Babinet, R.

    1987-03-01

    Angular distributions of cross section, and Ay and Ayy analysing powers were measured for polarised deuteron elastic scattering from 16O at 200, 400 and 700 MeV. The data at 200 MeV bear evidence of the nuclear rainbow phenomenon while those at 400 and 700 MeV are reminiscent of the proton scattering results at equivalent energies. The data were analysed in terms of the optical model. The real central potential shape changes from an attractive Woods-Saxon form at 200 MeV to a wine-bottle-bottom form with a repulsive interior at 700 MeV. The total reaction cross sections deduced display a clear nuclear transparency effect in the present energy domain in agreement with predictions from the Glauber theory optical limit. Comparison with previous results for 40Ca and 58Ni targets is made.

  2. Observations of gamma radiation between 0.4 MeV and 7 MeV at balloon altitudes using a Compton telescope

    NASA Technical Reports Server (NTRS)

    Lockwood, J. A.; Webber, W. R.; Friling, L. A.; Macri, J.; Hsieh, L.

    1981-01-01

    Balloon-borne measurements of the atmospheric and diffuse gamma-ray flux in the energy range 0.4-7.0 MeV with a Compton telescope, which included pulse-shape discrimination of the first scattering detector and a time-of-flight system between the first and second detector elements, are reported. Comparison of the diffuse cosmic gamma-ray flux to the atmospheric gamma rays indicates that 0.2-5.0 MeV is the optimum energy range for measurements made at the top of the earth's atmosphere. The measured total atmospheric gamma-ray flux between zero and 40 deg has an energy spectrum that agrees with the calculations of Ling (1975). Observations indicate that the ratio of the diffuse to atmospheric gamma ray fluxes at 3.5 g/sq cm is a maximum, about 1.0, between 0.7 and 3.0 MeV.

  3. Angular distribution of 4.43-MeV γ-rays produced in inelastic scattering of 14.1-MeV neutrons by 12C nuclei

    NASA Astrophysics Data System (ADS)

    Bystritsky, V. M.; Grozdanov, D. N.; Zontikov, A. O.; Kopach, Yu. N.; Rogov, Yu. N.; Ruskov, I. N.; Sadovsky, A. B.; Skoy, V. R.; Barmakov, Yu. N.; Bogolyubov, E. P.; Ryzhkov, V. I.; Yurkov, D. I.

    2016-07-01

    The work is devoted to measuring the angular distribution of 4.43-MeV γ-rays produced in inelastic scattering of 14.1-MeV neutrons by 12C nuclei. A portable ING-27 neutron generator (designed and fabricated at VNIIA, Moscow) with a built-in 64-pixel silicon α-detector was used as a source of tagged neutrons. The γ-rays of characteristic nuclear radiation from 12C were detected with a spectrometric system that consisted of 22 γ-detectors based on NaI(Tl) crystals arranged around the carbon target. The measured angular distribution of 4.43-MeV γ-rays is analyzed and compared with the results of other published experimental works.

  4. NEUTRON MULTIPLICITY AND ACTIVE WELL NEUTRON COINCIDENCE VERIFICATION MEASUREMENTS PERFORMED FOR MARCH 2009 SEMI-ANNUAL DOE INVENTORY

    SciTech Connect

    Dewberry, R.; Ayers, J.; Tietze, F.; Klapper, K.

    2010-02-05

    The Analytical Development (AD) Section field nuclear measurement group performed six 'best available technique' verification measurements to satisfy a DOE requirement instituted for the March 2009 semi-annual inventory. The requirement of (1) yielded the need for SRNL Research Operations Department Material Control & Accountability (MC&A) group to measure the Pu content of five items and the highly enrich uranium (HEU) content of two. No 14Q-qualified measurement equipment was available to satisfy the requirement. The AD field nuclear group has routinely performed the required Confirmatory Measurements for the semi-annual inventories for fifteen years using sodium iodide and high purity germanium (HpGe) {gamma}-ray pulse height analysis nondestructive assay (NDA) instruments. With appropriate {gamma}-ray acquisition modeling, the HpGe spectrometers can be used to perform verification-type quantitative assay for Pu-isotopics and HEU content. The AD nuclear NDA group is widely experienced with this type of measurement and reports content for these species in requested process control, MC&A booking, and holdup measurements assays Site-wide. However none of the AD HpGe {gamma}-ray spectrometers have been 14Q-qualified, and the requirement of reference 1 specifically excluded a {gamma}-ray PHA measurement from those it would accept for the required verification measurements. The requirement of reference 1 was a new requirement for which the Savannah River National Laboratory (SRNL) Research Operations Department (ROD) MC&A group was unprepared. The criteria for exemption from verification were: (1) isotope content below 50 grams; (2) intrinsically tamper indicating or TID sealed items which contain a Category IV quantity of material; (3) assembled components; and (4) laboratory samples. Therefore all (SRNL) Material Balance Area (MBA) items with greater than 50 grams total Pu or greater than 50 grams HEU were subject to a verification measurement. The pass

  5. 76Se(t,p)78Se reaction at 17 MeV

    NASA Astrophysics Data System (ADS)

    Watson, D. L.; Fortune, H. T.

    1987-02-01

    The 76Se(t,p)78Se reaction has been studied at an incident energy of 17 MeV. Excitation energies for 80 states (or groups of states) up to 6.16 MeV have been measured. Angular distributions have been obtained for 61 of them, below Ex=5.03 MeV. Comparison of the data with distorted-wave Born approximation calculations, using pure configurations for the transfer amplitudes, have enabled the L transfer (and hence Jπ value) to be determined for 58 of these states. Of these assignments, 52 are new.

  6. Elastic neutron scattering at 96 MeV from 12C and 208Pb

    NASA Astrophysics Data System (ADS)

    Klug, J.; Blomgren, J.; Ataç, A.; Bergenwall, B.; Hildebrand, A.; Johansson, C.; Mermod, P.; Nilsson, L.; Pomp, S.; Tippawan, U.; Elmgren, K.; Olsson, N.; Jonsson, O.; Prokofiev, A. V.; Renberg, P.-U.; Nadel-Turonski, P.; Dangtip, S.; Phansuke, P.; Österlund, M.; Le Brun, C.; Lecolley, J. F.; Lecolley, F. R.; Louvel, M.; Marie-Noury, N.; Schweitzer, C.; Eudes, Ph.; Haddad, F.; Lebrun, C.; Koning, A. J.; Bauge, E.; Delaroche, J. P.; Girod, M.; Ledoux, X.; Romain, P.; Madland, D. G.; Amos, K.; Deb, P. K.; Karataglidis, S.; Crespo, R.; Moro, A. M.

    2003-03-01

    A facility for detection of scattered neutrons in the energy interval 50 130 MeV, scattered nucleon detection assembly, has recently been installed at the 20 180 MeV neutron beam line of The Svedberg Laboratory, Uppsala. First results on elastic neutron scattering from 12C and 208Pb at 96 MeV incident neutron energy are presented. This experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. The results are compared with modern optical model predictions.

  7. The reaction proton deuteron yields triton pion at 470 and 590 MeV

    NASA Technical Reports Server (NTRS)

    Dollhopf, W.; Lunke, C.; Perdrisat, C. F.; Roberts, W. K.; Kitching, P.; Olsen, W. C.; Priest, J. R.

    1973-01-01

    The preliminary results from a study of the deuteron (proton, positive pion)triton reaction are reported. The differential cross section for this reaction was measured for a number of center of mass angles from 37 deg to 160 deg at incident proton energies of 470 and 590 MeV. The cross sections measured at 590 MeV agree with predictions made considering a two-nucleon process. The 470 MeV data shows a peak in the backward direction which is not predicted by this mechanism.

  8. Comparison of bactericidal efficiency of 7.5 MeV X-rays, gamma-rays, and 10 MeV e-beams

    NASA Astrophysics Data System (ADS)

    Song, Beom-Seok; Lee, Yunjong; Moon, Byeong-Geum; Go, Seon-Min; Park, Jong-Heum; Kim, Jae-Kyung; Jung, Koo; Kim, Dong-Ho; Ryu, Sang-Ryeol

    2016-08-01

    This study was performed to verify the feasibility of 7.5 MeV X-rays for food pasteurization through a comparison of the bactericidal efficiency with those of other sources for selected bacterial pathogens. No significant differences were observed between the overall bactericidal efficiency for beef-inoculated pathogens based on the uncertainty of the absorbed dose and variations in bacterial counts. This result supported that all three irradiation sources were effective for inactivation of food-borne bacteria and that 7.5 MeV X-rays may be used for food pasteurization.

  9. Title V Semi-Annual Emissions Report for Permit P100R1 July 1, 2011 - December 31, 2011

    SciTech Connect

    Whetham, Walter

    2012-03-15

    Reports of actual emissions from permitted sources in Section 2.0 shall be submitted on a 6 month basis. Reports shall not include emissions from insignificant activities. Emission estimates of criteria pollutants NOx, CO, SO2, PM and VOCs shall not include fugitive emissions. Emission estimates of HAPs shall include fugitive emissions. The reports shall include a comparison of actual emissions that occurred during the reporting period with the facility-wide allowable emission limits specified in Section 2.11 of this permit. The report required by Condition 4.1 shall be submitted within 90 days from the end of the reporting period. The semiannual report required by Condition 4.2 shall be submitted within 45 days from the end of the reporting period. The reporting periods are January 1st to June 30th and July 1st to December 31st. This condition is pursuant to 20.2.70.302.E.1 NMAC.

  10. Isotope Separation and Advanced Manufacturing Technology. ISAM semiannual report, Volume 3, Number 1, October 1993--March 1994

    SciTech Connect

    Carpenter, J.; Kan, T.

    1994-10-01

    This is the fourth issue of a semiannual report for the Isotope Separation and Advanced Materials Manufacturing (ISAM) Technology Program at Lawrence Livermore National Laboratory. Primary objectives include: (I) the Uranium Atomic Vapor Laser Isotope Separation (UAVLIS) process, which is being developed and prepared for deployment as an advanced uranium enrichment capability; (II) Advanced manufacturing technologies, which include industrial laser and E-beam material processing and new manufacturing technologies for uranium, plutonium, and other strategically important materials in support of DOE and other national applications. This report features progress in the ISAM Program from October 1993 through March 1994. Selected papers were indexed separately for inclusion in the Energy Science and Technology Database.

  11. Advanced Researech and Technology Development fossil energy materials program: Semiannual progress report for the period ending September 30, 1988

    SciTech Connect

    Not Available

    1989-01-01

    The objective of the ARandTD Fossil Energy Materials Program is to conduct research and development on materials for fossil energy applications with a focus on the longer-term and generic needs of the various fossil fuel technologies. The program includes research aimed toward a better understanding of materials behavior in fossil energy environments and the development of new materials capable of substantial enhancement of plant operations and reliability. The ORNL Fossil Energy Materials Program Office compiles and issues this combined semiannual progress report from camera-ready copies submitted by each of the participating subcontractor organizations. This report of activities on the program is organized in accordance with a work breakdown structure in which projects are organized according to materials research thrust areas. These areas are (1) Structural Ceramics, (2) Alloy Development and Mechanical Properties, (3) Corrosion and Erosion of Alloys, and (4) Assessments and Technology Transfer. Individual projects are processed separately for the data bases.

  12. F-Area Hazardous Waste Management Facility Semiannual Corrective Action Report, First and Second Quarter 1998, Volume I and II

    SciTech Connect

    Chase, J.

    1998-10-30

    This report addresses groundwater quality and monitoring data during first and second quarter 1998 for the F-Area Hazardous Waste management Facility (HWMF). The report fulfills the semiannual reporting requirements of Module III, Section D, of the 1995 Resource Conservation and Recovery Act (RCRA) Renewal Permit (South Carolina Hazardous and Mixed Waste Permit SC1-890-008-989), effective October 5, 1995 (hereafter referred to as the RCRA permit), and Section C of the Underground Injection Control Permit Application hereafter referred to as the Section C of the Underground Injection Control Permit Application (hereafter referred to as the UIC permit). The HWMF is described in the Introduction to Module III, Section C, of the RCRA permit.

  13. Semi-annual report of the Department of Energy, Office of Environmental Restoration and Waste Management, Quality Assessment Program

    SciTech Connect

    Sanderson, C.G.; Klusek, C.S.

    1993-07-01

    This Quality Assessment Program (QAP) is designed to test the quality of the environmental measurements being reported to the Department of Energy by its contractors. Since 1976, real or synthetic environmental samples that have been prepared and thoroughly analyzed at the Environmental Measurements Laboratory (EML) have been distributed at first quarterly and then semi-annually to these contractors. Their results, which are returned to EML within 90 days, are compiled with EML`s results and are reported back to the participating contractors 30 days later. A summary of the reported results is available to the participants 3 days after the reporting deadline via a modem-telephone connection to the EML computer. This report presents the results from the analysis of the 38th set of environmental quality assessment samples (QAP XXXVIII) that were received on or before June 2, 1993.

  14. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  15. Measurement of inner radiation belt electrons with kinetic energy above 1 MeV

    NASA Astrophysics Data System (ADS)

    Selesnick, R. S.

    2015-10-01

    Data from the Proton-Electron Telescope on the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) satellite, taken during 1992-2009, are analyzed for evidence of inner radiation belt electrons with kinetic energy E > 1 MeV. It is found that most of the data from a detector combination with a nominal energy threshold of 1 MeV were, in fact, caused by a chance coincidence response to lower energy electrons or high-energy protons. In particular, there was no detection of inner belt or slot region electrons above 1 MeV following the 2003 Halloween storm injection, though they may have been present. However, by restricting data to a less-stable, low-altitude trapping region, a persistent presence of inner belt electrons in the energy range 1 to 1.6 MeV is demonstrated. Their soft, exponential energy spectra are consistent with extrapolation of lower energy measurements.

  16. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H‑ beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  17. Semi-annual sampling of Fourmile Branch and its seeplines in the F and H Areas of SRS: July 1992

    SciTech Connect

    Dixon, K.L.; Rogers, V.A.

    1994-04-01

    In July 1992, water samples were collected from Fourmile Branch (FMB) and its seeplines in the vicinity of the F and H-Area seepage basins. The samples were collected from five seepline locations in F Area, five seepline locations in H Area, and three stream locations on FMB. The sampling event was the first in a series of three semi-annual sampling event was the first in a series of three semi-annual sampling events aimed at characterizing the shallow groundwater outcropping into FMB and its wetlands. In the past, this groundwater has been shown to contain contaminants migrating from the F- and H-Area seepage basins. The samples were analyzed for Appendix 9 metals, various radionuclides, selected volatile compounds, and selected inorganic constituents and parameters. Results from the July 1992 sampling event suggest that the seeplines in both F and H Areas and FMB continue to be influenced by contaminants migrating from the F- and H-Area seepage basins. However, when compared to 1989 measurements, the concentrations of most of the constituents have declined. Contaminant concentration measured in July 1992 were compared to primary drinking water standards (PDWS), secondary drinking water standards (SDWS), and maximum contaminant levels (MCL) enforceable in 1993. Results were also compared to 1989 measurements at corresponding sampling locations and to background samples collected as part of the July 1992 sampling event. Using two different statistical tests, concentrations of selected F- and H-Area seepline analytes were compared to background samples. These tests were designed to detect if concentrations of contaminants along the F- and H-Area seeplines were greater than background concentrations.

  18. Observation of a 1750 MeV narrow meson decaying into ηη

    NASA Astrophysics Data System (ADS)

    Alde, D.; Binon, F.; Bricman, C.; Donskov, S. V.; Gouanère, M.; Inyakin, A. V.; Kachanov, V. A.; Kakauridze, D. B.; Khaustov, G. V.; Knapp, E. A.; Kulik, A. V.; Lagnaux, J. P.; Lednev, A. A.; Mikhailov, Yu. V.; Mouthuy, Th.; Peigneux, J. P.; Prokoshkin, Yu. D.; Rodnov, Yu. V.; Sadovsky, S. A.; Samoilenko, V. D.; Shagin, P. M.; Shtannikov, A. V.; Singovsky, A. V.; Stroot, J. P.; Sugonyaev, V. P.

    1986-12-01

    A narrow meson which decays into ηη is observed in 38 GeV/c π-p collisions at large momentum transfer. The experiment has been performed at the Serpukhov accelerator with the GAMS-2000 spectrometer. The mass of this new meson is (1755 +/- 8) MeV, its width is less than 50 MeV. Its spin-parity is JPC=0++ or less probably 2++.

  19. The alpha optical potential at 1,370 MeV

    NASA Astrophysics Data System (ADS)

    Bauhoff, W.

    1986-06-01

    Data for elastic scattering of alpha particles from12C and Ca-isotopes at 1,370 MeV are analyzed in terms of a phenomenological optical potential. No evidence is found for deviations of the real part from the usual Woods-Saxon shape, as it is the case for proton scattering at corresponding energies. A further increase in nuclear transparency is found compared to 700 MeV.

  20. Measurement and evaluation of selected 14-MeV neutron cross sections for fusion

    SciTech Connect

    Meadows, J.W.; Smith, D.L.; Cox, S.A.

    1985-01-01

    Experimental neutron-activation cross-section data in the vicinity of 14 MeV are evaluated for several reactions of fusion-related interest using a least-squares method. New experimental measurements are performed at 14.7 MeV for all of these considered reactions and for some commonly-used standard reactions as well. Comparison is made between measured and evaluated results.

  1. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    NASA Astrophysics Data System (ADS)

    Osipenko, M.; Ripani, M.; Alba, R.; Ricco, G.; Schillaci, M.; Barbagallo, M.; Boccaccio, P.; Celentano, A.; Colonna, N.; Cosentino, L.; Del Zoppo, A.; Di Pietro, A.; Esposito, J.; Figuera, P.; Finocchiaro, P.; Kostyukov, A.; Maiolino, C.; Santonocito, D.; Scuderi, V.; Viberti, C. M.

    2013-09-01

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a 3He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10 MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60-70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.

  2. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  3. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV.

    PubMed

    Sakata, S; Arikawa, Y; Kojima, S; Ikenouchi, T; Nagai, T; Abe, Y; Inoue, H; Morace, A; Utsugi, M; Kato, R; Nishimura, H; Nakai, M; Shiraga, H; Fujioka, S; Azechi, H

    2014-11-01

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (Ne = 1.0 × 10(-6) C, Ee = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%-70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10(-7), 10(-4), 10(-5), respectively, for 2-10, 11-15, and 15-25 MeV of photon energy ranges.

  4. Corrosion under argon irradiation of titanium in the low MeV range: A study coupling AFM and Spectroscopic Ellipsometry

    NASA Astrophysics Data System (ADS)

    Do, Ngoc-Long; Garcia-Caurel, Enric; Bérerd, Nicolas; Moncoffre, Nathalie; Gorse-Pomonti, Dominique

    2014-05-01

    This paper reports on a recent study of the corrosion under argon ion irradiation of titanium in the low MeV range (1-9 MeV), associating AFM and Spectroscopic Ellipsometry. Irradiation with MeV Arn+ (n = 1, 3) ions produces damages on the titanium surface. Large craters form on the oxidized titanium surface whose characteristics vary as a function of the argon energy between 2 and 9 MeV. The superficial oxide grows thicker under irradiation over the same energy range, especially near 3 MeV. It is suggested that collisions cascades play a significant role in the overall damage process.

  5. Inspector General Semiannual Report to Congress - October 1, 2008 - March 31, 2009

    SciTech Connect

    2008-10-01

    On behalf of the Department of Energy's Office of Inspector General, I am pleased to submit our Semiannual Report to Congress for the period ending March 31, 2009. The Report highlights key accomplishments of the Office of Inspector General, particularly pertaining to our efforts to ensure the economy, efficiency, and effectiveness of Department of Energy operations. Details pertaining to some of our most significant reviews and projects are presented in the Report. This reporting period has been quite eventful. On February 17, 2009, the President signed the American Recovery and Reinvestment Act of 2009. The stated intent of this new legislation is to strengthen the U.S. economy through the creation of new jobs, aiding State and local governments with budget shortfalls, cutting taxes for working families, and investing in the long-term health of the Nation's economic prosperity. The Recovery Act establishes the status of the Nation's energy supply as a prime focus. Specifically, the Department of Energy will receive approximately $40 billion for various energy, environmental, and science programs and initiatives. The passage of this legislation makes the coming months an exciting and transformative time for the Department of Energy and the Office of Inspector General. In recognition of the need for effective oversight to protect taxpayer interests, the Recovery Act includes the creation of the Recovery Act Accountability and Transparency Board and mandates specific actions by the Inspectors General. I will be a permanent member of this newly created Board, along with nine other Inspectors General whose agencies are significant recipients of Recovery Act funds. Since the passage of the legislation, my office has developed a strategy consistent with the objectives outlined in the Recovery Act. The overarching goal of the strategy is to ensure that the taxpayers interests relating to the performance and results of the Recovery Act are protected. During this reporting

  6. Inertial Conference Fusion Semiannual Report October 1999 - March 2000, Volume 1, Number 1

    SciTech Connect

    Hammel, B A

    2000-03-01

    This first issue of the ''ICF Semiannual Report'' contains articles whose diverse subjects attest to the broad technical and scientific challenges that are at the forefront of the ICF program at LLNL. The first article describes the progress being made at solving the surface roughness problem on capsule mandrels. All NIF capsule options, except machined beryllium, require a mandrel upon which the ablator is deposited. This mandrel sets the baseline sphericity of the final capsule. Problems involving defects in the mandrel have been overcome using various techniques so that 2-mm-size mandrels can now be made that meet the NIF design specification. The second article validates and provides a detailed numerical investigation of the shadowgraph technique currently used to diagnose the surface roughness of a fuel ice layer inside of a transparent capsule. It is crucial for the success of the indirect-drive ignition targets that the techniques used to characterize ice-surface roughness be well understood. This study identifies methods for analyzing the bright band that give an accurate measure of the ice-surface roughness. The third article describes a series of realistic laser and target modifications that can lead to 3-4 times more energy coupling and 10 times greater yield from a NIF indirect-drive ignition target. Target modifications include using various mixtures of rare-earth and other high-Z metals as hohlraum wall material and adjusting the laser-entrance-hole size and the case-to-capsule size ratio. Each option is numerically examined separately and together. The fourth article reviews how detailed x-ray and Thomson scattering measurements from a high-density and high-temperature gasbag plasma are used to test spectroscopic modeling techniques. There is good agreement between the model and experimental dielectronic capture satellite intensities. However, improvements are required in the modeling of inner shell collisionally populated satellite states. These

  7. Complete identification of states in 208Pb below Ex=6.2 MeV

    NASA Astrophysics Data System (ADS)

    Heusler, A.; Jolos, R. V.; Faestermann, T.; Hertenberger, R.; Wirth, H.-F.; von Brentano, P.

    2016-05-01

    The Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium of the Ludwig-Maximilians-Universität München and the Technische Universität München (Garching, Germany), was used to study the 208Pb(p ,p' ) , 206,207,208Pb (d,p), and 208Pb(d ,d' ) reactions. One hundred fifty-one states at Ex<6.20 MeV in 208Pb are identified and spin and parity assigned. Four states are newly identified and new spins and/or parities are assigned to 25 states. Tentative spin assignments are done to five states at 5.90 MeV . Nearly 50 levels below Ex=6.20 MeV listed by the Nuclear Data Sheets as of 2007 are recognized to be nonexistent or doubly placed. The schematic shell model describing one-particle-one-hole configurations without residual interaction is extended by including two-particle-two-hole configurations. The number of configurations thus predicted at Ex<6.20 MeV nearly agrees with the number of states identified. Several states with dominant two-particle-two-hole configurations are identified. New isobaric analog resonances in 209Bi with two-particle-one-hole structure are discovered at Eres=17.6 MeV . The excitation energies of 70 states with unnatural parity at Ex<6.20 MeV are found to agree within about 200 keV with one-particle-one-hole configurations predicted by the extended schematic shell model. In contrast, the excitation energies of about 20 natural parity states are more than 0.5 MeV lower than predicted, demonstrating the residual interaction among the configurations to be much larger for natural parity than for unnatural parity.

  8. Upper limit on the inner radiation belt MeV electron intensity

    PubMed Central

    Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

    2015-01-01

    No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Key Points Quantified upper limit of MeV electrons in the inner belt Actual MeV electron intensity likely much lower than the upper limit More detailed understanding of relativistic electrons in the magnetosphere PMID:26167446

  9. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    NASA Astrophysics Data System (ADS)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The 242Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  10. Highly Stripped Ion Sources for MeV Ion Implantation

    SciTech Connect

    Hershcovitch, Ady

    2009-06-30

    Original technical objectives of CRADA number PVI C-03-09 between BNL and Poole Ventura, Inc. (PVI) were to develop an intense, high charge state, ion source for MeV ion implanters. Present day high-energy ion implanters utilize low charge state (usually single charge) ion sources in combination with rf accelerators. Usually, a MV LINAC is used for acceleration of a few rnA. It is desirable to have instead an intense, high charge state ion source on a relatively low energy platform (de acceleration) to generate high-energy ion beams for implantation. This de acceleration of ions will be far more efficient (in energy utilization). The resultant implanter will be smaller in size. It will generate higher quality ion beams (with lower emittance) for fabrication of superior semiconductor products. In addition to energy and cost savings, the implanter will operate at a lower level of health risks associated with ion implantation. An additional aim of the project was to producing a product that can lead to long­ term job creation in Russia and/or in the US. R&D was conducted in two Russian Centers (one in Tomsk and Seversk, the other in Moscow) under the guidance ofPVI personnel and the BNL PI. Multiple approaches were pursued, developed, and tested at various locations with the best candidate for commercialization delivered and tested at on an implanter at the PVI client Axcelis. Technical developments were exciting: record output currents of high charge state phosphorus and antimony were achieved; a Calutron-Bemas ion source with a 70% output of boron ion current (compared to 25% in present state-of-the-art). Record steady state output currents of higher charge state phosphorous and antimony and P ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb {sup 4 +}, Sb{sup 5+}, and Sb{sup 6+} respectively. Ultimate commercialization goals did not succeed (even though a number of the products like high

  11. Observations of 1-30 MeV gamma rays from the galactic center

    NASA Technical Reports Server (NTRS)

    Zanrosso, E.; Long, J. L.; Zych, A. D.; White, R. S.

    1981-01-01

    Preliminary results are reported for gamma ray observations of the galactic center region made during a 15-hour balloon flight from Alice Springs, Australia on April 18, 1979. The observations were carried out with the UGR double-scatter gamma-ray telescope at energies of 1 to 30 MeV. The observations are compatible with a galactic source of approximately equal brightness along the region of system II galactic longitudes between 300 and 60 deg. The energy distribution joins smoothly to previous spark chamber results at energies above 30 MeV and to scintillator results below 1 MeV. It appears to be a combination of nuclear gamma ray lines superimposed on a power-law bremsstrahlung spectrum. The metastable C-12 line at 4.4 MeV appears to be present with a significance of about 16 standard deviations. The flux in the line is 0.0006 + or - 0.0003 photons/sq cm per sec per rad. The oxygen line at 6.1 MeV does not seem to appear significantly above background.

  12. Elastic neutron scattering at 96 MeV from 12 C and 208 Pb

    NASA Astrophysics Data System (ADS)

    Klug, J.; Blomgren, J.; Ataç, A.; Bergenwall, B.; Hildebrand, A.; Johansson, C.; Mermod, P.; Nilsson, L.; Pomp, S.; Tippawan, U.; Elmgren, K.; Olsson, N.; Jonsson, O.; Prokofiev, A. V.; Renberg, P.-U.; Nadel-Turonski, P.; Dangtip, S.; Phansuke, P.; Österlund, M.; Le Brun, C.; Lecolley, J. F.; Lecolley, F. R.; Louvel, M.; Marie-Noury, N.; Schweitzer, C.; Eudes, Ph.; Haddad, F.; Lebrun, C.; Koning, A. J.; Ledoux, X.

    2003-12-01

    A facility for detection of scattered neutrons in the energy interval 50 130 MeV , SCANDAL, has recently been installed at the 20 180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12 C and 208 Pb has been studied at 96 MeV in the 10° 70° interval. The achieved energy resolution, 3.7 MeV , is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated normalization uncertainty, 3% , is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions based on phenomenology or microscopic nuclear theory.

  13. Gamma ray lines from solar flares. [with 2.2 MeV line being strongest

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1974-01-01

    The strongest line, both predicted theoretically and detected observationally at 2.2 MeV, is due to neutron capture by protons in the photosphere. The neutrons are produced in nuclear reactions of flare accelerated particles which also positrons and prompt nuclear gamma rays. From the comparison of the observed and calculated intensities of the lines at 4.4 or 6.1 MeV to that of the 2.2 MeV line, it is possible to deduce the spectrum of accelerated nuclei in the flare region; and from the absolute intensities of these lines, it is possible to obtain the total number of accelerated nuclei at the sun. The study of the 2.2 MeV line also gives information on the amount of He-3 in the photosphere. The study of the line at 0.51 MeV resulting from positron annihilation complements the data obtained from the other lines; in addition it gives information on the temperature and density in the annihilation region.

  14. Modification of semiconductor or metal nanoparticle lattices in amorphous alumina by MeV heavy ions

    NASA Astrophysics Data System (ADS)

    Bogdanović Radović, I.; Buljan, M.; Karlušić, M.; Jerčinović, M.; Dražič, G.; Bernstorff, S.; Boettger, R.

    2016-09-01

    In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature.

  15. Environmentally assisted cracking in light water reactors : semiannual report, July 2000 - December 2000.

    SciTech Connect

    Chopra, O. K.; Chung, H. M.; Gruber, E. E.; Shack, W. J.; Soppet, W. K.; Strain, R. V.; Energy Technology

    2002-04-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from July 2000 to December 2000. Topics that have been investigated include (a) environmental effects on fatigue S-N behavior of primary pressure boundary materials, (b) irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels (SSs), and (c) EAC of Alloys 600 and 690. The fatigue strain-vs.-life data are summarized for the effects of various material, loading, and environmental parameters on the fatigue lives of carbon and low-alloy steels and austenitic SSs. Effects of the reactor coolant environment on the mechanism of fatigue crack initiation are discussed. Two methods for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations are presented. Slow-strain-rate tensile tests and posttest fractographic analyses were conducted on several model SS alloys irradiated to {approx}0.9 x 10{sup 21} n {center_dot} cm{sup -2} (E > 1 MeV) in He at 289 C in the Halden reactor. The results were used to determine the influence of alloying and impurity elements on the susceptibility of these steels to IASCC. A fracture toughness J-R curve test was conducted on a commercial heat of Type 304 SS that was irradiated to {approx}2.0 x 10{sup 21} n {center_dot} cm{sup -2} in the Halden reactor. The results were compared with the data obtained earlier on steels irradiated to 0.3 and 0.9 x 10{sup 21} n {center_dot} cm{sup -2} (E > 1 MeV) (0.45 and 1.35 dpa). Neutron irradiation at 288 C was found to decrease the fracture toughness of austenitic SSs. Tests were conducted on compact-tension specimens of Alloy 600 under cyclic loading to evaluate the enhancement of crack growth rates in LWR environments. Then, the existing fatigue crack growth data on Alloys 600 and 690 were analyzed to establish the effects of temperature, load ratio, frequency, and stress intensity range

  16. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of natU

    NASA Astrophysics Data System (ADS)

    Penttilä, H.; Gorelov, D.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I. D.; Parkkonen, J.; Peräjärvi, K.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Rubchenya, V. A.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Äystö, J.

    2016-04-01

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {}^{nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {}^{nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution.

  17. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

    SciTech Connect

    Sakata, S. Arikawa, Y.; Kojima, S.; Ikenouchi, T.; Nagai, T.; Abe, Y.; Inoue, H.; Morace, A.; Utsugi, M.; Nishimura, H.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H.; Kato, R.

    2014-11-15

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (N{sub e} = 1.0 × 10{sup −6} C, E{sub e} = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%–70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10{sup −7}, 10{sup −4}, 10{sup −5}, respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.

  18. Limits on the antiproton/proton ratio in the cosmic radiation from 100 MeV to 1580 MeV

    NASA Technical Reports Server (NTRS)

    Salamon, M. H.; Mckee, S.; Musser, J. A.; Tarle, G.; Tomasch, A.

    1990-01-01

    A search for antiprotons (p-bars) in the cosmic radiation with energies below 1580 MeV at the top of the atmosphere was performed using the PBAR balloon-borne magnetic spectrometer. No antiprotons were observed in 124,000 proton events. For the energy interval 100-640 MeV, an upper limit is reported to the p-bar/p ratio of 2.8 x 10 to the -5th at the top of the atmosphere, after correcting for instrumental efficiencies and contributions from secondary particles. No antiproton was observed in the energy interval 640-1580 MeV, which yields an upper limit to the p-bar/p ratio of 6.1 x 10. By combining both data sets, the limits on the p-bar/p ratio can be improved to 2.0 x 10 to the -5th. The detector performance and instrumental efficiencies of the individual detector components are discussed. A detail Monte Carlo calculation was used to evaluate the instrumental efficiency for both antiprotons and protons as a function of momentum.

  19. Resonance frequency control for the KOMAC 100-MeV drift tube linac

    NASA Astrophysics Data System (ADS)

    Kwon, Hyeok-Jung

    2015-02-01

    A 100-MeV proton accelerator has been developed, and the operation and beam service started at the Korea Multi-purpose Accelerator Complex (KOMAC) in July 2013. The accelerator consists of a 50-keV proton injector, a 3-MeV radio-frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The resonance frequencies of the DTL tanks are controlled by using the resonance frequency control cooling system (RCCS), installed at every DTL tank. Until now, the RCCS has been operating in the constant temperature mode. If the system is to be stabilized better, the RCCS must be operated in the frequency control mode. For this purpose, studies, including the relation between the resonance frequency and RCCS operation temperature, were done under various conditions. In this paper, the preparations for the frequency control loop of the RCCS are described.

  20. The 500-MeV, 2 1/2% duty factor linear electron accelerator (MEA)

    SciTech Connect

    Bruinsma, P.J.T.; Kroes, F.B.; Kuijer, L.H.; Noomen, J.G.; Spelt, J.B.; Vogel, A.G.C.

    1983-08-01

    Although the intermediate energy electron accelerator in Amsterdam has not reached completely its design specifications, since early 1981 a fully grown scientific program has developed using beams with an energy ranging from 20 to 120 MeV in the 140 MeV substation (for radio-chemistry and low-energy electron scattering over 180/sup 0/) and from 70 to 400 MeV in the high energy stations for electron scattering and physics with pion and muon beams. A brief description of the MIT-type accelerator and its performance will be given with emphasis on typical features of the machine. Some examples will be given of recently obtained scientific data from which can be derived that the quality of the beam is in full accordance with the high performance level of the scientific equipment, involving a complex beam transport system and a pair of spectrometers for high resolution (1x10/sup -4/) work.

  1. Evidence for a 3.8 MeV state in 9Be

    NASA Astrophysics Data System (ADS)

    Smith, R.; Wheldon, C.; Freer, M.; Curtis, N.; Kokalova, Tz.; Almaraz-Calderon, S.; Aprahamian, A.; Ashwood, N. I.; Barr, M.; Bucher, B.; Copp, P.; Couder, M.; Fang, X.; Goldring, G.; Jung, F.; Lesher, S. R.; Lu, W.; Malcolm, J. D.; Roberts, A.; Tan, W. P.; Ziman, V. A.

    2016-07-01

    The breakup reaction 9Be(4He,3 α )n was measured using an array of four double-sided silicon strip detectors at beam energies of 22 and 26 MeV. Excited states in 9Be up to 8 MeV were populated and reconstructed through measurements of the charged reaction products. Evidence is given for a state in 9Be at 3 .82-0.09+0.08 MeV with Γ =1240-90+270 keV. This is consistent with two recent measurements of a state with similar properties in the mirror nucleus 9B. An analysis of the reduced widths (g.s.8Be channel) of this state along with the proposed mirror state has led to a firm limit of J ≤7 /2 and a tentative assignment of Jπ=1 /2- or 3 /2- .

  2. A proposed diagnostic for time-resolved 14 MeV neutron measurements on TFTR

    SciTech Connect

    Ku, L.P.; Nazikian, R.; Prorvitch, V.

    1990-06-01

    A novel method for time resolved measurements of the 14 MeV neutron flux in an intense 2.5 MeV neutron and {gamma}-ray background has been developed. Discrimination against the background 2.5 MeV neutron and {gamma}-ray flux is achieved by the use of polyethylene and lead shielding. A high detection efficiency of DT neutrons is obtained by the use of large volume plastic scintillators and photomultiplier tube designed for operating in high magnetic field environments. Design computations for a such a detector system on TFTR show that an absolute detection efficiency of {approximately}10{sup {minus}8} counts per DT neutron may be obtained. A source strength of 10{sup 13} DT n/s may readily be detected by this method using both count mode and current mode operation with a resolution of {approximately}10 ms within a statistical accuracy of {approximately}5%. 12 refs., 8 figs., 2 tabs.

  3. Commissioning and first operational experience of the 400 MeV Linac at Fermilab

    SciTech Connect

    Junck, K.; Allen, L.; Kroc, T.; MacLachlan, J.; McCrory, E.; Moretti, A.; Noble, R.; Popovic, M.; Schmidt, C.

    1994-07-01

    Commissioning of the Fermilab High Energy Linac during September and October of 1993 has increased the energy of the H- linac from 200 to 400 MeV. The Linac Upgrade is one portion of the Fermilab Upgrad and is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster. To accomplish this increase in energy within the existing enclosure, four 201.25 MHz drift-tube linac tankshave been replaced by seven 805 MHz side-coupled cavity modules to accelerate the beam from 116 MeV to 400 MeV. Each module is driven with a klystron amplifier delivering 10 MW of peak power for 60 {mu}sec with a maximum pulse repetition rate of 15 Hz. Nominal beam current is 35 mA with a pulselength of 40 {mu}sec. Results from commissioning and operational experience during Fermilab Collider Run 1B are presented.

  4. Neutron-induced 2.2 MeV background in gamma ray telescopes

    NASA Technical Reports Server (NTRS)

    Zanrosso, E. M.; Long, J. L.; Zych, A. D.; White, R. S.

    1985-01-01

    Neutron-induced gamma ray production is an important source of background in Compton scatter gamma ray telescopes where organic scintillator material is used. Most important is deuteron formation when atmospheric albedo and locally produced neutrons are thermalized and subsequently absorbed in the hydrogenous material. The resulting 2.2 MeV gamma ray line radiation essentially represents a continuous isotropic source within the scintillator itself. Interestingly, using a scintillator material with a high hydrogen-to-carbon ratio to minimize the scintillator material with a high hydrogen-to-carbon ratio to minimize the neutron-induced 4.4 MeV carbon line favors the np reaction. The full problem of neutron-induced background in Compton scatter telescopes has been previously discussed. Results are presented of observations with the University of California balloon-borne Compton scatter telescope where the 2.2 MeV induced line emission is prominently seen.

  5. MeV ion-beam analysis of optical data storage films

    NASA Technical Reports Server (NTRS)

    Leavitt, J. A.; Mcintyre, L. C., Jr.; Lin, Z.

    1993-01-01

    Our objectives are threefold: (1) to accurately characterize optical data storage films by MeV ion-beam analysis (IBA) for ODSC collaborators; (2) to develop new and/or improved analysis techniques; and (3) to expand the capabilities of the IBA facility itself. Using H-1(+), He-4(+), and N-15(++) ion beams in the 1.5 MeV to 10 MeV energy range from a 5.5 MV Van de Graaff accelerator, film thickness (in atoms/sq cm), stoichiometry, impurity concentration profiles, and crystalline structure were determined by Rutherford backscattering (RBS), high-energy backscattering, channeling, nuclear reaction analysis (NRA) and proton induced X-ray emission (PIXE). Most of these techniques are discussed in detail in the ODSC Annual Report (February 17, 1987), p. 74. The PIXE technique is briefly discussed in the ODSC Annual Report (March 15, 1991), p. 23.

  6. Semiannual and solar activity variations of daytime plasma observed by DEMETER in the ionosphere-plasmasphere transition region

    NASA Astrophysics Data System (ADS)

    Li, L. Y.; Cao, J. B.; Yang, J. Y.; Berthelier, J. J.; Lebreton, J.-P.

    2015-12-01

    Using the plasma data of Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite and the NRLMSISE-00 atmospheric model, we examined the semiannual and solar activity variations of the daytime plasma and neutral composition densities in the ionosphere-plasmasphere transition region (~670-710 km). The results demonstrate that the semiannually latitudinal variation of the daytime oxygen ions (O+) is basically controlled by that of neutral atomic oxygen (O), whereas the latitude distributions of the helium and hydrogen ions (He+ and H+) do not fully depend on the neutral atomic helium (He) and hydrogen (H). The summer enhancement of the heavy oxygen ions is consistent with the neutral O enhancement in the summer hemisphere, and the oxygen ion density has significantly the summer-dense and winter-tenuous hemispheric asymmetry with respect to the dip equator. Although the winter enhancements of the lighter He+ and H+ ions are also associated with the neutral He and H enhancements in the winter hemisphere, the high-density light ions (He+ and H+) and electrons (e-) mainly appear at the low and middle magnetic latitudes (|λ| < 50°). The equatorial accumulations of the light plasma species indicate that the light charged particles (He+, H+, and e-) are easily transported by some equatorward forces (e.g., the magnetic mirror force and centrifugal force). The frequent Coulomb collisions between the charged particles probably lead to the particle trappings at different latitudes. Moreover, the neutral composition densities also influence their ion concentrations during different solar activities. From the low-F10.7 year (2007-2008) to the high-F10.7 year (2004-2005), the daytime oxygen ions and electrons increase with the increasing neutral atomic oxygen, whereas the daytime hydrogen ions tend to decrease with the decreasing neutral atomic hydrogen. The helium ion density has no obvious solar activity variation, suggesting that the

  7. RF phase stability in the 100-MeV proton linac operation

    NASA Astrophysics Data System (ADS)

    Seol, Kyung-Tae

    2015-02-01

    The 100-MeV proton linac of the Korea multi-purpose accelerator complex (KOMAC) has been operated to provide a proton beam to users. The 100-MeV linac consists of a 3-MeV radio-frequency quadrupole accelerator (RFQ), four 20-MeV drift-tube linac (DTL) tanks, two medium-energy beam-transmitter (MEBT) tanks, and seven 100-MeV DTL tanks. The requirements of the field stability are within ±1% in RF amplitude and ±1 degree in RF phase. The RF phase stability is influenced by a RF reference line, RF transmission lines, and a RF control system. The RF reference signal is chosen to be a 300-MHz local oscillator (LO) signal, and a rigid copper coaxial line with temperature control was installed for an RF reference distribution. A phase stability of ±0.1 degrees was measured under a temperature change of ±0.1 °C. A digital feedback control system with a field-programmable gate-array (FPGA) module was adopted for a high RF stability. The RF phase was maintained within ±0.1 degrees with a dummy cavity and was within ±0.3 degrees at RFQ operation. In the case of the 20-MeV DTL tanks, one klystron drives 4 tanks, and the input phases of 4 tanks were designed to be in phase. The input phases of 4 tanks were fixed within ±1 degree by adjusting a phase shifter in each waveguide.

  8. Technical Note: On Cerrobend shielding for 18-22 MeV electron beams

    SciTech Connect

    Wojcicka, Jadwiga B.; Yankelevich, Rafael; Werner, Barry Leonard; Lasher, Donette E.

    2008-10-15

    The purpose of this study is to investigate (1) the depth at which the measurement of the block transmission factor should be made, and (2) the level of the transmission of 18 and 22 MeV electron beams through conventional Cerrobend. We measured the block transmission in water phantom as ionization profiles across the beam and as ionization distributions along the central axis of the beam for 18 and 22 MeV electron beams, for cone sizes ranging from 6x10 cm{sup 2} to 25x25 cm{sup 2}. In our analysis, we separated the bremsstrahlung component produced in the Cerrobend block from the component originating in the head in the transmitted dose under the standard Cerrobend block. The block transmission for both beam energies and cone sizes was maximum on the central axis of the beam at depths between 0.4 and 0.7 cm. For the 18 MeV beam, the maximum transmission was 6.2% for the 6x10 cm{sup 2} cone, and 7.4% for the 25x25 cm{sup 2} cone. For the 22 MeV beam, it was 9.5% for the 6x10 cm{sup 2} cone, and 11.3% for the 25x25 cm{sup 2} cone. For the 22 MeV beam and 15x15 cm{sup 2} cone, it takes 2.95 and 1.4 cm of Cerrobend to reduce the maximum block transmission to 5% and 10%, respectively. The maximum dose under a blocked electron beam occurs on the central axis closer to the surface than it does for the open beam, and the block transmission factor should be defined at this shallower depth. To decrease the block transmission factor to the level of 5% on the central axis, electron beams with energy 18 MeV and greater require additional shielding.

  9. Neutron induced fission of U isotopes up to 100 MeV

    SciTech Connect

    Lestone, J.P.; Gavron, A.

    1993-10-01

    We have developed a statistical model description of the neutron induced fission of U isotopes using densities of intrinsic states and spin cut off parameters obtained directly from appropriate Nilsson model single particle levels. The first chance fission cross sections are well reproduced when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second chance fission, we need to: (1) assume that the triaxial level density enhancement is washed out at an excitation energy of {approximately}7 MeV above the triaxial barriers with a width of {approximately}1 MeV, implying a {gamma} deformation for the first barriers of 10{degree} < {gamma} < 20{degree}; and (2) include pre-equilibrium particle emission in the calculations. Above an incoming neutron kinetic energy of {approximately}17 MeV our statistical model U(n,f) cross sections increasingly overestimate the experimental data when so called ``good`` optical model potentials are used to calculate the compound nucleus formation cross sections. This is not surprising since at these high energies little data exists on the scattering of neutrons to help guide the choice of optical model parameters. A satisfactory reproduction of all the available U(n,f) cross sections above 17 MeV is obtained by a simple scaling of our calculated compound nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV.

  10. Cross sections of the (n ,p ) reaction on the 78Se and 80Se isotopes measured for 13.73 MeV to 14.77 MeV and estimated for 10 MeV to 20 MeV neutron energies

    NASA Astrophysics Data System (ADS)

    Attar, F. M. D.; Dhole, S. D.; Bhoraskar, V. N.

    2014-12-01

    The cross sections of 78Se(n ,p ) 78As and 80Se(n ,p ) 80As reactions were measured at five neutron energies over the range 13.73 MeV to 14.77 MeV using 56Fe and 19F as monitor elements, respectively. The cross sections were also theoretically estimated using EMPIRE-II and TALYS codes over 10 MeV to 20 MeV neutrons and matched with the experimental cross sections by making proper choice of the model parameters. The theoretical and experimental cross sections of 80Se(n ,p ) 80As reaction are smaller as compared to the 78Se(n ,p ) 78As reaction at each neutron energy. This difference is attributed to the competing 80Se(n ,2 n )79Se and 80Se( n ,α )Ge77m reactions, which effectively decrease the cross sections of 80Se(n ,p ) 80As reaction as compared to that of the 78Se(n ,p ) 78As reaction over the neutron energy range used in the present work. The cross sections of 78Se(n ,p ) 78As and 80Se(n ,p ) 80As reactions estimated by the EMPIRE-II code initially increase but later on decrease with neutron energy, respectively, above 16 MeV and 19 MeV, whereas those estimated by the TALYS code continuously increase with neutron energy. The present results indicate that the trends in the variation of cross section with neutron energy depend on the model used in the calculations. The cross sections of the 80Se(n ,p ) 80As reaction at different neutron energies reported in the present work can be added as a new data in the nuclear data library.

  11. Energy monitoring device for 1.5-2.4 MeV electron beams

    NASA Astrophysics Data System (ADS)

    Fuochi, P. G.; Lavalle, M.; Martelli, A.; Kovács, A.; Mehta, K.; Kuntz, F.; Plumeri, S.

    2010-03-01

    An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.

  12. Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

    NASA Astrophysics Data System (ADS)

    Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.

    2015-05-01

    The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation.

  13. Loss of alpha-like MeV fusion products from TFTR

    SciTech Connect

    Zweben, S.J.; Boivin, R.L.; Diesso, M.; Hayes, S.E.; Hendel, H.W.; Park, H.; Strachan, J.D.

    1990-03-01

    A detailed comparison between the observed and expected loss of alpha-like MeV fusion products in TFTR is presented. The D-D fusion products (mainly the 1 MeV triton) were measured with an 2-D imaging scintillation detector. The expected first-orbit loss was calculated with a simple Lorentz orbit code. In almost all cases the measured loss was consistent with the expected first-orbit loss model. Exceptions are noted for small major radius plasmas and during strong MHD activity. 37 refs., 28 figs.

  14. Protactinium neutron-induced fission up to 200 MeV

    NASA Astrophysics Data System (ADS)

    Maslov, V.

    2010-03-01

    The theoretical evaluation of 230-233Pa(n,F) cross sections is based on direct data, 230-234Pa fission probabilities and ratios of fission probabilities in first-chance and emissive fission domains, surrogate for neutroninduced fission. First chance fission cross sections trends of Pa are based on consistent description of 232Th(n,F), 232Th(n,2n) and 238U(n,F), 238U(n,xn) data, supported by the ratio surrogate data by Burke et al., 2006, for the 237U(n,F) reaction. Ratio surrogate data on fission probabilities of 232Th(6 Li,4 He)234Pa and 232 Th(6 Li,d)236U by Nayak et al., 2008, support the predicted 233Pa(n, F) cross section at En=11.5-16.5 MeV. The predicted trends of 230-232Pa(n, F) cross section up to En=20 MeV, are consistent with fissilities of Pa nuclides, extracted by 232Th(p,F) (Isaev et al., 2008) and 232Th(p,3n) (Morgenstern et al., 2008) data analysis. The excitation energy and nucleon composition dependence of the transition from asymmetric to symmetric scission for fission observables of Pa nuclei is defined by analysis of p-induced fission of 232Th at Ep=1-200 MeV. Predominantly symmetric fission in 232Th(p,F) at En( p)=200 MeV as revealed by experimental branching ratios (Dujvestijn et al., 1999) is reproduced. Steep transition from asymmetric to symmetric fission with increase of nucleon incident energy is due to fission of neutron-deficient Pa (A≤229) nuclei. A structure of the potential energy surface (a drop of f f symmetric and asymmetric fission barriers difierence (EfSYM - EfASYM) from ~3.5 MeV to ~1 MeV) of N-deficient Pa nuclides (A≤226) and available phase space at outer fission saddles, are shown to be responsible for the sharp increase with En( p) of the symmetric fission component contribution for 232Th(p,F) and 230-233 Pa(n, F) reactions. That is a strong evidence of emissive fission nature of moderately excited Pa nuclides, reliably quantified only up to En( p)~20(30) MeV. Predicted fission cross section of 232Pa(n,F) coincides

  15. Inelastic scattering of 61 MeV protons by pb-207

    NASA Technical Reports Server (NTRS)

    Owais, M.

    1976-01-01

    Differential cross sections for the excitation of the first four neutron-hole states and the doublet at 2.61 MeV by 61.2 MeV protons were measured. The data are analyzed in terms of both a purely collective model description and a microscopic model supplemented by macroscopic core polarization. A realistic two-body interaction is used and knock-on amplitudes are included. Core polarization is found to be important but represents a relatively smaller contribution than in most nuclei previously studied. A parallel analysis of similar data at lower proton bombarding energies reveals a surprisingly strong energy dependence of the reaction mechanisms.

  16. Interaction of MeV ions and VUV photons with polymers and high molecular hydrocarbons

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Sauer, M.; Atwa, S. T.; Kaiser, R. I.; Roessler, K.

    1992-03-01

    Organic solids such as polymethylene, polyethylene, polyoxymethylene, aliphatic and cyclic paraffins, naphthalene, anthracene and kerogen were irradiated at 77 K with 10-20 MeV cyclotron ions (p, 3He) and up to 10 eV photons. The products were analysed by quadrupole mass spectrometry (QMS). Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and gas chromatography (GC). Besides radiolytic fragmentation, also synthesis of new and complex compounds was observed as a consequence of hot carbon chemistry. Vacuum ultraviolet (VUV) irradiation proved to be less effective in the buildup of new structures than MeV ions, due to its lower linear energy transfer.

  17. Clarification of the three-body decay of 12C (12.71 MeV).

    PubMed

    Fynbo, H O U; Prezado, Y; Bergmann, U C; Borge, M J G; Dendooven, P; Huang, W X; Huikari, J; Jeppesen, H; Jones, P; Jonson, B; Meister, M; Nyman, G; Riisager, K; Tengblad, O; Vogelius, I S; Wang, Y; Weissman, L; Wilhelmsen Rolander, K; Aystö, J

    2003-08-22

    Using beta decays of a clean source of 12N produced at the IGISOL facility, we have measured the breakup of the 12C (12.71 MeV) state into three alpha particles with a segmented particle detector setup. The high quality of the data permits solving the question of the breakup mechanism of the 12.71 MeV state, a longstanding problem in few-body nuclear physics. Among existing models, a modified sequential model fits the data best, but systematic deviations indicate that a three-body description is needed.

  18. Absolute polarimeter for the proton-beam energy of 200 MeV

    SciTech Connect

    Zelenski, A. N.; Atoian, G.; Bogdanov, A. A.; Nurushev, S. B.; Pylaev, F. S.; Raparia, D.; Runtso, M. F.; Stephenson, E.

    2013-12-15

    A polarimeter is upgraded and tested in a 200-MeV polarized-proton beam at the accelerator-collider facility of the Brookhaven National Laboratory. The polarimeter is based on the elastic polarizedproton scattering on a carbon target at an angle of 16.2°, in which case the analyzing power is close to unity and was measured to a very high degree of precision. It is shown that, in the energy range of 190–205 MeV, the absolute polarization can be measured to a precision better than ±0.5%.

  19. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies

    NASA Astrophysics Data System (ADS)

    Abbott, D.; Adderley, P.; Adeyemi, A.; Aguilera, P.; Ali, M.; Areti, H.; Baylac, M.; Benesch, J.; Bosson, G.; Cade, B.; Camsonne, A.; Cardman, L. S.; Clark, J.; Cole, P.; Covert, S.; Cuevas, C.; Dadoun, O.; Dale, D.; Dong, H.; Dumas, J.; Fanchini, E.; Forest, T.; Forman, E.; Freyberger, A.; Froidefond, E.; Golge, S.; Grames, J.; Guèye, P.; Hansknecht, J.; Harrell, P.; Hoskins, J.; Hyde, C.; Josey, B.; Kazimi, R.; Kim, Y.; Machie, D.; Mahoney, K.; Mammei, R.; Marton, M.; McCarter, J.; McCaughan, M.; McHugh, M.; McNulty, D.; Mesick, K. E.; Michaelides, T.; Michaels, R.; Moffit, B.; Moser, D.; Muñoz Camacho, C.; Muraz, J.-F.; Opper, A.; Poelker, M.; Réal, J.-S.; Richardson, L.; Setiniyaz, S.; Stutzman, M.; Suleiman, R.; Tennant, C.; Tsai, C.; Turner, D.; Ungaro, M.; Variola, A.; Voutier, E.; Wang, Y.; Zhang, Y.; PEPPo Collaboration

    2016-05-01

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19 MeV /c , limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  20. Design of a compact spectrometer for high-flux MeV gamma-ray beams

    SciTech Connect

    Corvan, D. J. Sarri, G.; Zepf, M.

    2014-06-15

    A novel design for a compact gamma-ray spectrometer is presented. The proposed system allows for spectroscopy of high-flux multi-MeV gamma-ray beams with MeV energy resolution in a compact design. In its basic configuration, the spectrometer exploits conversion of gamma-rays into electrons via Compton scattering in a low-Z material. The scattered electron population is then spectrally resolved using a magnetic spectrometer. The detector is shown to be effective for gamma-ray energies between 3 and 20 MeV. The main properties of the spectrometer are confirmed by Monte Carlo simulations.

  1. Experimental evidence of the superfocusing effect for axially channeled MeV protons

    NASA Astrophysics Data System (ADS)

    Motapothula, M.; Petrović, S.; Nešković, N.; Breese, M. B. H.

    2016-08-01

    Sub-Ångström focusing of megaelectronvolt (MeV) ions within axial channels was predicted over 10 years ago, but evidence proved elusive. We present experimental angular distributions of axially channeled MeV protons in a 55-nm-thick (001) silicon membrane through which multiple scattering is negligible. Fine angular structure is in excellent agreement with Monte Carlo simulations based on three interaction potentials, providing indirect evidence of the existence of the superfocusing effect with flux enhancement of around 800 within a focused beam width of ˜20 pm .

  2. Design of a compact spectrometer for high-flux MeV gamma-ray beams.

    PubMed

    Corvan, D J; Sarri, G; Zepf, M

    2014-06-01

    A novel design for a compact gamma-ray spectrometer is presented. The proposed system allows for spectroscopy of high-flux multi-MeV gamma-ray beams with MeV energy resolution in a compact design. In its basic configuration, the spectrometer exploits conversion of gamma-rays into electrons via Compton scattering in a low-Z material. The scattered electron population is then spectrally resolved using a magnetic spectrometer. The detector is shown to be effective for gamma-ray energies between 3 and 20 MeV. The main properties of the spectrometer are confirmed by Monte Carlo simulations.

  3. Thin Object Radiography with a 2.2 MeV Pulsed Power Machine

    NASA Astrophysics Data System (ADS)

    Haines, Todd; Danielson, Jeremy; Wood, W. Monty

    2015-06-01

    An experimental series was performed at a pulsed-power 2.2 MeV flash radiography machine to determine the lower limits of its mass sensitivity. This machine uses a rod-pinch diode with accelerating potential of 2.2 MeV and 50 ns pulse duration. Tungsten, aluminum, and titanium rod anodes were used to tune the emitted bremsstrahlung spectrum; as well as aluminum and beryllium filter materials. Analysis of thin tantalum foils shows a mass sensitivity as low as 300 μg/cm2. This is a factor of 5 better than previous measurements.

  4. Neutron-induced charged-particle emission studies below 100 MeV at WNR

    SciTech Connect

    Haight, R.C.; Lee, T.M.; Sterbenz, S.M.

    1994-07-01

    Charged-particles produced by neutron bombardment of selected targets with Z=5 through 53 have been studied for neutron energies from 1 MeV to about 100 MeV using the spallation neutron source at WNR/LAMPF. Particle detection with energy measurement and particle identification is accomplished by two-element {Delta}E-E counters, three-element {Delta}E{sub l}-{Delta}E{sub 2}-E counters or with pulse-shape discrimination using scintillators directly in the neutron beam. The experimental techniques for these measurements are described and comparisons made among the different approaches. This presentation introduces five papers contributed to this conference.

  5. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    NASA Astrophysics Data System (ADS)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani

    2012-06-01

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O7+ ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O7+ ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  6. MeV negative ion generation from ultra-intense laser interaction with a water spray

    SciTech Connect

    Ter-Avetisyan, S.; Ramakrishna, B.; Borghesi, M.; Doria, D.; Zepf, M.; Sarri, G.; Ehrentraut, L.; Steinke, S.; Sandner, W.; Schnuerer, M.; Andreev, A.; Nickles, P. V.; Tikhonchuk, V.

    2011-08-01

    MeV negative oxygen ions are obtained from a water spray target irradiated by high intensity (5 x 10{sup 19} W/cm{sup 2}) and ultrashort (50 fs) laser pulses. Generation of negative ions is ascribed to electron-capture processes that the laser-accelerated high-energy positive ion experiences when it interacts with atoms in the spray. This mechanism implies the existence of a large number of MeV neutral oxygen atoms, which is consistent with indirect experimental evidence.

  7. MeV heavy ion microprobe PIXE for the analysis of the materials surface

    NASA Astrophysics Data System (ADS)

    Mokuno, Y.; Horino, Y.; Kinomura, A.; Chayahara, A.; Kiuchi, M.; Fujii, K.; Takai, M.

    1994-03-01

    Micro PIXE analysis using MeV phosphorus microprobes was performed to a surface structure which consists of multilevel aluminum wirings in silicon nitride and these results were compared with those from a proton microprobe. In the case of a 2 MeV phosphorus microprobe, the X-ray production was enhanced near the surface due to the large energy deposition rate or the short projectile range. As a result, the increase in surface sensitivity was clearly shown in PIXE mapping images of aluminum, silicon, and phosphorus.

  8. GRB spectra in the MeV range: hints from INTEGRAL

    SciTech Connect

    Bulik, Tomasz; Denis, Miroslaw; Marcinkowski, Radoslaw; Goldoni, Paolo; Laurent, Philip; Osuch, Lukasz

    2007-07-12

    INTEGRAL detects a large number of gamma-ray bursts outside of its field of view with the SPI ACS. Several of these bursts are also detected by IBIS. We present the results of the spectral analysis using the ISRGI, PICSIT and Compton mode data of several bursts. These bursts show very hard spectra with the high energy index reaching -2 above 1 MeV We show that there is a group of bursts with the peak energy Epeak in the MeV range. We discuss the implications of these findings for GLAST.

  9. Neutron scattering measurements in {sup 197}Au from 850 keV to 2.0 MeV

    SciTech Connect

    O`Connor, M.; Chen, J.; Egan, J.J.

    1995-10-01

    Differential elastic and inelastic neutron scattering cross-sections for low lying levels in {sup 197}Au have been measured for incident neutron energies of 1.0 MeV, 1.5 MeV and 2.0 MeV. In addition, the total neutron cross sections in {sup 197}Au was measured from 850 keV to 1.5 MeV. For both experiments the UML 5.5 MV Van-de-Graaff accelerator with a Mobley post acceleration compression system, produced subnanosecond proton pulses which generated neutrons via the {sup 7}Li(p,n) {sup 7}Be reaction.

  10. Environmentally assisted cracking in light water reactors. Semiannual report, July 1998-December 1998.

    SciTech Connect

    Chopra, O. K.; Chung, H. M.; Gruber, E. E.; Kassner, T. F.; Ruther, W. E.; Shack, W. J.; Smith, J. L.; Soppet, W. K.; Strain; R. V.

    1999-10-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from July 1998 to December 1998. Topics that have been investigated include (a) environmental effects on fatigue S-N behavior of primary pressure boundary materials, (b) irradiation-assisted stress corrosion cracking of austenitic stainless steels (SSs), and (c) EAC of Alloys 600 and 690. Fatigue tests have been conducted to determine the crack initiation and crack growth characteristics of austenitic SSs in LWR environments. Procedures are presented for incorporating the effects of reactor coolant environments on the fatigue life of pressure vessel and piping steels. Slow-strain-rate tensile tests and posttest fractographic analyses were conducted on several model SS alloys irradiated to {approx}0.3 and 0.9 x 10{sup 21} n {center_dot} cm{sup -2} (E > 1 MeV) in helium at 289 C in the Halden reactor. The results have been used to determine the influence of alloying and impurity elements on the susceptibility of these steels to irradiation-assisted stress corrosion cracking. Fracture toughness J-R curve tests were also conducted on two heats of Type 304 SS that were irradiated to {approx}0.3 x 10{sup 21} n {center_dot} cm{sup -2} in the Halden reactor. Crack-growth-rate tests have been conducted on compact-tension specimens of Alloys 600 and 690 under constant load to evaluate the resistance of these alloys to stress corrosion cracking in LWR environments.

  11. In situ infrared study of catalytic decomposition of NO. Semiannual technical progress report, February 1--August 1, 1996

    SciTech Connect

    Chuang, S.S.C.; Tan, C.D.

    1996-09-20

    During the second semi-annual period, promotion of oxygen desorption to enhance direct NO decomposition over Tb-Pt/Al{sub 2}O{sub 3} catalyst has been studied. Promotion of oxygen desorption at low temperatures holds the key to the development of an effective NO decomposition catalyst. Addition of Tb-oxide to Pt/Al{sub 2}O{sub 3} allows oxygen from dissociated NO to desorb at 593 K which is significantly lower than the reported oxygen desorption temperatures for Pt catalysts. Combined temperature-programmed desorption/reaction with in situ infrared study reveals that desorbed oxygen is produced from decomposition of chelating bidentate nitrato which may be resulted from the reaction of adsorbed oxygen on Pt and adsorbed NO on Tb-oxide. The Tb-promoted Pt/Al{sub 2}O{sub 3} catalyst which possess oxygen desorption capability at low temperatures shows the activity for decomposition of NO to N{sub 2}, N{sub 2}O, and O{sub 2} at 723 K.

  12. Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry

    USGS Publications Warehouse

    Mursula, K.; Tanskanen, E.; Love, J.J.

    2011-01-01

    We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993-2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a dominant annual variation, with equinoctial maxima alternating between Spring in solar cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the solar wind. A similar, large annual variation is found in the solar wind driver of substorms and geomagnetic activity, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic activity is not due to ionospheric conditions but to a hemispherically asymmetric distribution of solar wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic activity has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of solar magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future. Copyright ?? 2011 by the American Geophysical Union.

  13. Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry

    USGS Publications Warehouse

    Marsula, K.; Tanskanen, E.; Love, J.J.

    2011-01-01

    We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a dominant annual variation, with equinoctial maxima alternating between Spring in solar cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the solar wind. A similar, large annual variation is found in the solar wind driver of substorms and geomagnetic activity, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic activity is not due to ionospheric conditions but to a hemispherically asymmetric distribution of solar wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic activity has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of solar magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future.

  14. Sampling and analyses report for June 1992 semiannual postburn sampling at the RM1 UCG site, Hanna, Wyoming

    SciTech Connect

    Lindblom, S.R.

    1992-08-01

    The Rocky Mountain 1 (RMl) underground coal gasification (UCG) test was conducted from November 16, 1987 through February 26, 1988 (United Engineers and Constructors 1989) at a site approximately one mile south of Hanna, Wyoming. The test consisted of dual module operation to evaluate the controlled retracting injection point (CRIP) technology, the elongated linked well (ELW) technology, and the interaction of closely spaced modules operating simultaneously. The test caused two cavities to be formed in the Hanna No. 1 coal seam and associated overburden. The Hanna No. 1 coal seam is approximately 30 ft thick and lays at depths between 350 ft and 365 ft below the surface in the test area. The coal seam is overlain by sandstones, siltstones and claystones deposited by various fluvial environments. The groundwater monitoring was designed to satisfy the requirements of the Wyoming Department of Environmental Quality (WDEQ) in addition to providing research data toward the development of UCG technology that minimizes environmental impacts. The June 1992 semiannual groundwater.sampling took place from June 10 through June 13, 1992. This event occurred nearly 34 months after the second groundwater restoration at the RM1 site and was the fifteenth sampling event since UCG operations ceased. Samples were collected for analyses of a limited suite set of parameters as listed in Table 1. With a few exceptions, the groundwater is near baseline conditions. Data from the field measurements and analysis of samples are presented. Benzene concentrations in the groundwater were below analytical detection limits.

  15. Semi-annual oscillation (SAO) of the nighttime ionospheric D-region as detected through ground-based VLF receivers

    NASA Astrophysics Data System (ADS)

    Silber, I.; Price, C. G.; Rodger, C. J.

    2015-11-01

    Earth's middle and upper atmosphere exhibits several dominant large scale oscillations in many measured parameters. One of these oscillations is the semi-annual oscillation (SAO). The SAO can be detected in the ionospheric total electron content (TEC), the ionospheric transition height, the wind regime in the mesosphere-lower-thermosphere (MLT), and in the MLT temperatures. In addition, as we report for the first time in this study, the SAO is among the most dominant oscillations in nighttime very low frequencies (VLF) narrow-band subionospheric measurements. As VLF signals are reflected off the ionospheric D-region (at altitudes of ~65 and ~85 km, during the day and night, respectively), this implies that the upper part of the D-region is experiencing this oscillation as well, through changes in the dominating electron or ion densities, or by changes in the electron collision frequency, recombination rates, and attachment rates, all of which could be driven by oscillatory MLT temperature changes. We conclude that the main source of the SAO in the nighttime D-region is due to NOx molecules transport from the lower levels of the thermosphere, resulting in enhanced ionization and the creation of free electrons in the nighttime D-region, thus modulating the SAO signature in VLF NB measurements. While the cause for the observed SAO is still a subject of debate, this oscillation should be taken into account when modeling the D-region in general and VLF wave propagation in particular.

  16. Semi-annual oscillation (SAO) of the nighttime ionospheric D region as detected through ground-based VLF receivers

    NASA Astrophysics Data System (ADS)

    Silber, Israel; Price, Colin; Rodger, Craig J.

    2016-03-01

    Earth's middle and upper atmosphere exhibits several dominant large-scale oscillations in many measured parameters. One of these oscillations is the semi-annual oscillation (SAO). The SAO can be detected in the ionospheric total electron content (TEC), the ionospheric transition height, the wind regime in the mesosphere-lower thermosphere (MLT), and in the MLT temperatures. In addition, as we report for the first time in this study, the SAO is among the most dominant oscillations in nighttime very low frequency (VLF) narrowband (NB) subionospheric measurements. As VLF signals are reflected off the ionospheric D region (at altitudes of ˜ 65 and ˜ 85 km, during the day and night, respectively), this implies that the upper part of the D region is experiencing this oscillation as well, through changes in the dominating electron or ion densities, or by changes in the electron collision frequency, recombination rates, and attachment rates, all of which could be driven by oscillatory MLT temperature changes. We conclude that the main source of the SAO in the nighttime D region is NOx molecule transport from the lower levels of the thermosphere, resulting in enhanced ionization and the creation of free electrons in the nighttime D region, thus modulating the SAO signature in VLF NB measurements. While the cause for the observed SAO is still a subject of debate, this oscillation should be taken into account when modeling the D region in general and VLF wave propagation in particular.

  17. Positron-electron decay of 28Si at an excitation energy of 50 MeV

    NASA Astrophysics Data System (ADS)

    Buda, A.; Bacelar, J. C.; Balanda, A.; van der Ploeg, H.; Sujkowski, Z.; van der Woude, A.

    1993-03-01

    The electron-position pair decay of 28Si at 50 MeV excitation produced by the isospin T=0 (α + 24Mg) and the mixed isospin T=0,1 (3He + 25Mg) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI.

  18. Flare vs. Shock Acceleration of >100 MeV Protons in Large Solar Particle Events

    NASA Astrophysics Data System (ADS)

    Cliver, Edward W.

    2016-05-01

    Recently several studies have presented correlative evidence for a significant-to-dominant role for a flare-resident process in the acceleration of high-energy protons in large solar particle events. In one of these investigations, a high correlation between >100 MeV proton fluence and 35 GHz radio fluence is obtained by omitting large proton events associated with relatively weak flares; these outlying events are attributed to proton acceleration by shock waves driven by coronal mass ejections (CMEs). We argue that the strong CMEs and associated shocks observed for proton events on the main sequence of the scatter plot are equally likely to accelerate high-energy protons. In addition, we examine ratios of 0.5 MeV electron to >100 MeV proton intensities in large SEP events, associated with both well-connected and poorly-connected solar eruptions, to show that scaled-up versions of the small flares associated with classical impulsive SEP events are not significant accelerators of >100 MeV protons.

  19. Residual Nuclei Production in the reaction {sup 136}Xe+ deuterium at 500 A MeV

    SciTech Connect

    Alcantara-Nunez, J. A.; Benlliure, J.; Perez-Loureiro, D.; Casarejos, E.; Fernandez Ordonez, M.; Pereira, J.; Armbruster, P.; Enqvist, T.; Henzl, V.; Henzlova, D.; Kelic, A.; Pleskac, R.; Ricciardi, M. V.; Schmidt, K.-H.; Schmitt, C.; Yordanov, O.; Audouin, L.; Bernas, M.; Lafriaskh, A.; Stephan, C.

    2010-04-26

    More than six hundred nuclei produced in the fragmentation of {sup 136}Xe projectiles at 500 A MeV on a liquid deuterium target were identified using inverse kinematics at the GSI Fragment Separator (FRS). These data are relevant for understanding of spallation reactions.

  20. Proton irradiation of conventional and lithium solar cells - 11-37 MeV

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.; Carter, J. R.

    1974-01-01

    Conventional n/p and lithium solar cells were irradiated with 11- to 37-MeV protons. The energy dependence of the solar cell degradation, calculated from electrical parameters and lifetime measurements, is shown to be very slight. Damage coefficients for the n/p cells are calculated. Annealing characteristics of both the lithium cells and the n/p cells are presented.

  1. Voltage holding study of 1 MeV accelerator for ITER neutral beam injector.

    PubMed

    Taniguchi, M; Kashiwagi, M; Umeda, N; Dairaku, M; Takemoto, J; Tobari, H; Tsuchida, K; Yamanaka, H; Watanabe, K; Kojima, A; Hanada, M; Sakamoto, K; Inoue, T

    2012-02-01

    Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration, which leads to discharge initiation at lower voltage. To reduce the electric field concentration in the MeV accelerator, gaps between the grid supports were expanded and curvature radii at the support corners were increased. After the modifications, the accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. However, the beam energy was still limited at a level of 900 keV with a beam current density of 150 A∕m(2) (346 mA) where the 3 × 5 apertures were used. Measurement of the beam profile revealed that deflection of the H(-) ions was large and a part of the H(-) ions was intercepted at the acceleration grid. This causes high heat load on the grids and the breakdowns during beam acceleration. To suppress the direct interception, new grid system was designed with proper aperture displacement based on a 3D beam trajectory analysis. As the result, the beam deflection was compensated and the voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A∕m(2) (427 mA), which is close to the requirement of ITER accelerator (1 MeV, 200 A∕m(2)).

  2. DPA damage analysis for 14-MeV neutrons on PFC materials

    NASA Astrophysics Data System (ADS)

    Kim, Dong-woo; Lee, Bo-young; Ko, Seung-kook; Kim, Hee-soo; Noh, Seung-jung

    2015-06-01

    The dpa (displacement per atom) damage for 14-MeV neutron in a pfc materials was simulated using MCNPX/SPECTER code. The dpa values in the main components of the structural material SS316L, Fe, Cr and Ni, were calculated to analyze the effect of nuclear damage. According to the neutron wall load for ITER design base, a neutron flux of 3.5 × 1013 neutrons/cm2·sec was applied. The simulated dpa values were found to be as 3.0 dpa/fpy for Fe, 2.9 dpa/fpy for Cr and 3.1 dpa/fpy for Ni. For practical experiments, the simulated dpa values due to the irradiation damage of 17-MeV protons were found to be as 0.67 dpa at the peak and 0.05 at the surface for SS316L using by SRIM code at the same fluence. For the 17-MeV proton irradiation, the Bragg peak appears at a 0.64-mm depth. Also, SS316L specimens irradiated by a 17-MeV proton beam with a fluence of 1016 protons/cm2 were analyzed by using transmission electron microscopy.

  3. Properties of 16C(6.11 MeV) and its mirror in 16Ne

    NASA Astrophysics Data System (ADS)

    Fortune, H. T.

    2016-07-01

    From previous data for the reaction 14C(t ,p )16C , I have extracted a width of 32.6(5) keV for the strong state at Ex=6.11 MeV . Here, I examine its likely Jπ and configuration. The predicted width of its mirror in 16Ne is estimated to be about 260 keV.

  4. Deuteron-proton breakup reaction at Ed=7.4 MeV

    NASA Astrophysics Data System (ADS)

    Kröger, H.; Nachabe, A. M.; Slobodrian, R. J.

    1986-04-01

    The reaction d+p-->p+p+n is investigated at Elabd=7.4 MeV. Calculations of the cross section are compared with recent kinematically complete measurements. The Coulomb potential is taken fully into account in the calculations based on the strong approximation of Mo/ller wave operator approach.

  5. Scintillation detector efficiencies for neutrons in the energy region above 20 MeV

    SciTech Connect

    Dickens, J.K.

    1991-01-01

    The computer program SCINFUL (for SCINtillator FUL1 response) is a program designed to provide a calculated complete pulse-height response anticipated for neutrons being detected by either an NE-213 (liquid) scintillator or an NE-110 (solid) scintillator in the shape of a right circular cylinder. The point neutron source may be placed at any location with respect to the detector, even inside of it. The neutron source may be monoenergetic, or Maxwellian distributed, or distributed between chosen lower and upper bounds. The calculational method uses Monte Carlo techniques, and it is relativistically correct. Extensive comparisons with a variety of experimental data have been made. There is generally overall good agreement (less than 10% differences) of results for SCINFUL calculations with measured integral detector efficiencies for the design incident neutron energy range of 0.1 to 80 MeV. Calculations of differential detector responses, i.e. yield versus response pulse height, are generally within about 5% on the average for incident neutron energies between 16 and 50 MeV and for the upper 70% of the response pulse height. For incident neutron energies between 50 and 80 MeV, the calculated shape of the response agrees with measurements, but the calculations tend to underpredict the absolute values of the measured responses. Extension of the program to compute responses for incident neutron energies greater than 80 MeV will require new experimental data on neutron interactions with carbon. 32 refs., 6 figs., 2 tabs.

  6. The 2-MEV Model: Constancy of Adolescent Environmental Values within an 8-Year Time Frame

    ERIC Educational Resources Information Center

    Bogner, F. X.; Johnson, B.; Buxner, S.; Felix, L.

    2015-01-01

    The 2-MEV model is a widely used tool to monitor children's environmental perception by scoring individual values. Although the scale's validity has been confirmed repeatedly and independently as well as the scale is in usage within more than two dozen language units all over the world, longitudinal properties still need clarification. The purpose…

  7. Measurement of the. pi. d. -->. pp reaction at T/sub. pi. / = 65 MeV

    SciTech Connect

    Ottermann, C.R.; Boschitz, E.T.; Gyles, W.; List, W.; Tacik, R.; Mango, S.; Konter, J.A.; van den Brandt, B.; Smith, G.R.

    1986-05-01

    The vector analyzing power iT/sub 11/ has been measured for the ..pi..d..-->..pp reaction at an incident pion energy of 65 MeV, using a vector polarized deuteron target. The data are compared with predictions from coupled channels, Faddeev, and perturbation theory calculations.

  8. Large momentum transfer neutron pickup with the (. pi. /sup +/,p) and (p,d) reactions. [90 and 180 MeV, 800 MeV

    SciTech Connect

    Smith, G.R.

    1980-01-01

    The (p,d) reaction was studied for the first time at 800 MeV on seven targets ranging from /sup 7/Li to /sup 40/Ca. The experimental resolution (approx. 400 keV) attained was sufficient to observe many discrete levels in each of the residual nuclei. A modified version of the one-nucleon model successfully describes the magnitude and angular dependence of almost all of the transitions observed. A specific counter example to the two-nucleon model of the reaction mechanism is suggested. The calculations are also sensitive to the neutron single-particle wave function, in accordance with the expectation that the high-momentum components of this wave function are probed at higher bombarding energies. States that have never been seen before were strongly populated in the high excitation region (up to 25 MeV) of some of the residual nuclei. The relative intensities of the other levels observed suggest that coupled-channels mechanisms play an important role for some of these states. Explicit calculations were performed to confirm this for several examples. The first high-resolution measurements of the (..pi../sup +/,p) reaction were also performed on /sup 6/Li, /sup 7/Li, /sup 12/C, and /sup 13/C at pion bombarding energies on and off the pion-nucleon resonance. Calculations employing a one-nucleon model of the reaction mechanism similar to the model successfully used for the (p,d) reaction are unable to account for transitions in the (..pi../sup +/,p) reaction. It is, however, unclear whether this failure is due to a fundamental inadequacy of the model or improper treatment of details in the calculations. A striking similarity was observed in the spectra of the (..pi../sup +/,p) and 800-MeV (p,d) reactions on the same target; this result implies a similar mechanism for the two reactions. 120 references, 97 figures, 15 tables.

  9. Acceleration of ampere class H(-) ion beam by MeV accelerator.

    PubMed

    Taniguchi, M; Inoue, T; Umeda, N; Kashiwagi, M; Watanabe, K; Tobari, H; Dairaku, M; Sakamoto, K

    2008-02-01

    The H(-) ion accelerator R&D to realize the international thermonuclear experimental reactor neutral beam is ongoing at Japan Atomic Energy Agency (JAEA). The required performance for the prototype MeV accelerator developed at JAEA is 1 MeV, 500 mA (current density of 200 A/m(2)) H(-) ion beam at the beamlet divergence angle of less than 7 mrad. Up to 2005, 836 keV, 146 A/m(2) H(-) ion beam was successfully accelerated as the highest record of the current density at MeV class energy beams. In the present work, high current negative ion beam acceleration test was performed by increasing the beam extraction apertures from 3 x 3 (9 apertures) to 3 x 5 (15 apertures). By fixing the air leak at the source chamber due to backstream ions as well as the improvement of voltage holding capability by a new fiber reinforced plastic insulator ring, the performance of the MeV accelerator was improved. So far, H(-) ion beam of 320 mA was successfully accelerated up to 796 keV with the beam divergence angle of 5.5 mrad. The accelerated drain current including the electron reaches close to the power supply limit for the MeV test facility. The heat flux by the backstream ion during the above beam acceleration was estimated to be 360 W/cm(2). The Cs leakage to the accelerator during the test campaign (Cs total input of 5.0 g) was 0.26 mg (7.0 microg/cm(2)). This is considered to be the allowable level from the viewpoint of voltage holding. PMID:18315236

  10. Measurement of 181 MeV H- ions stripping cross-sections by carbon stripper foil

    NASA Astrophysics Data System (ADS)

    Saha, P. K.; Yoshimoto, M.; Yamazaki, Y.; Hotchi, H.; Harada, H.; Okabe, K.; Kinsho, M.; Irie, Y.

    2015-03-01

    The stripping cross-sections of 181 MeV H- (negative hydrogen) ions by the carbon stripper foil are measured with good accuracy. The present experiment was carried out at the 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex). The stripping cross-sections for different charge states, also known as electron loss cross-sections of H- ion, are denoted as σ-11, σ-10 and σ01, for both electrons stripping (H- →H+), one-electron stripping (H- →H0) and the 2nd-electron stripping (H0 →H+) proceeding σ-10, respectively. We have established very unique and precise techniques for such measurements so as also to determine a foil stripping efficiency very accurately. The cross-sections σ-11, σ-10 and σ01 are obtained to be (0.002 ± 0.001) ×10-18cm2, (1.580 ± 0.034) ×10-18cm2 and (0.648 ± 0.014) ×10-18cm2, respectively. The presently given cross-sections are newly available experimental results for an incident H- energy below 200 MeV and they are also shown to be consistent with recently proposed energy (1 /β2) scaled cross-sections calculated from the previously measured data at 200 and 800 MeV. The present results have a great importance not only at J-PARC for the upgraded H- beam energy of 400 MeV but also for many new and upgrading similar accelerators, where H- beam energies in most cases are considered to be lower than 200 MeV.

  11. Development of mass spectrometry by high energy focused heavy ion beam: MeV SIMS with 8 MeV Cl7+ beam

    NASA Astrophysics Data System (ADS)

    Jeromel, Luka; Siketić, Zdravko; Ogrinc Potočnik, Nina; Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen; Pelicon, Primož

    2014-08-01

    Particle induced X-ray emission (PIXE) at microprobe of Jožef Stefan Institute is used to measure two-dimensional quantitative elemental maps of biological tissue. To improve chemical and biological understanding of the processes in vivo, supplementary information about chemical bonding and/or molecular distributions could be obtained by heavy-ion induced molecular desorption and a corresponding mass spectroscopy with Time-Of-Flight (TOF) mass spectrometer. As the method combines the use of heavy focused ions in MeV energy range and TOF Secondary Ion Mass Spectrometry, it is denoted as MeV SIMS. At Jožef Stefan Institute, we constructed a linear TOF spectrometer and mount it to our multipurpose nuclear microprobe. A beam of 8 MeV 35Cl7+ could be focused to a diameter of better than 3 μm × 3 μm and pulsed by electrostatic deflection at the high-energy side of accelerator. TOF mass spectrometer incorporates an 1 m long drift tube and a double stack microchannel plate (MCP) as a stop detector positioned at the end of the drift path. Secondary ions are focused at MCP using electrostatic cylindrical einzel lens. Time of flight spectra are currently acquired with a single-hit time-to-digital converter. Pulsed ion beam produces a shower of secondary ions that are ejected from positively biased target and accelerated towards MCP. We start our time measurement simultaneously with the start of the beam pulse. Signal of the first ion hitting MCP is used to stop the time measurement. Standard pulses proportional to the time of flight are produced with time to analog converter (TAC) and fed into analog-to-digital converter to obtain a time histogram. To enable efficient detection of desorbed fragments with higher molecular masses, which are of particular interest, we recently implemented a state-of art Field Programmable Gate Array (FPGA)-based multi-hit TOF acquisition. To test the system we used focused 8 MeV 35Cl7+ ion beam with pulse length of 180 ns. Mass resolution

  12. Development of an intelligent grinding wheel for in-process monitoring of ceramic grinding. Semi-annual report {number_sign}3

    SciTech Connect

    Malkin, S.; Gao, R.; Guo, C.; Varghese, B.; Pathare, S.

    1998-03-26

    This is the third semi-annual report for the project. The overall objective of this project is to develop sensor-integrated intelligent diamond wheels for grinding of ceramics. Such wheels will be smart enough to monitor and supervise both the wheel preparation and grinding processes without the need to instrument the machine tool. Intelligent wheels will utilize re-useable cores integrated with sensors: to measure the acoustic emission (AE) and grinding force. Signals from the sensors will be transmitted from a rotating wheel to a receiver by telemetry. Wheels will be trained to recognize distinct characteristics associated with truing, dressing and grinding. The technical progress is summarized in this report.

  13. Near-earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations

    DOE PAGES

    Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John R.; Cattell, Cynthia A.; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel N.; et al

    2015-08-10

    Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeV electron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L~5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ~40 s and a dispersionless injection of electrons up to ~3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front.more » Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.« less

  14. Near-earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations

    SciTech Connect

    Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John R.; Cattell, Cynthia A.; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel N.; Li, Xinlin; Malaspina, David; Blake, J. Bernard; Fennell, Joseph; Claudepierre, Seth; Turner, Drew L.; Reeves, Geoffrey D.; Funsten, Herbert O.; Spence, Harlan E.; Angelopoulos, Vassilis; Fruehauff, Dennis; Chen, Lunjin; Thaller, Scott; Breneman, Aaron; Tang, Xiangwei

    2015-08-10

    Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeV electron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L~5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ~40 s and a dispersionless injection of electrons up to ~3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.

  15. Response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV

    NASA Astrophysics Data System (ADS)

    Crespi, F. C. L.; Avigo, R.; Camera, F.; Akkoyun, S.; Ataç, A.; Bazzacco, D.; Bellato, M.; Benzoni, G.; Blasi, N.; Bortolato, D.; Bottoni, S.; Bracco, A.; Brambilla, S.; Bruyneel, B.; Ceruti, S.; Ciemała, M.; Coelli, S.; Eberth, J.; Fanin, C.; Farnea, E.; Gadea, A.; Giaz, A.; Gottardo, A.; Hess, H.; Kmiecik, M.; Leoni, S.; Maj, A.; Mengoni, D.; Michelagnoli, C.; Million, B.; Montanari, D.; Nicolini, R.; Pellegri, L.; Recchia, F.; Reiter, P.; Riboldi, S.; Ur, C. A.; Vandone, V.; Valiente-Dobon, J. J.; Wieland, O.; Wiens, A.; Agata Collaboration

    2013-03-01

    The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(11B,nγ)12C at Ebeam=19.1 MeV, while gamma rays between 2 and 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%.Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation caused by n-capture in Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape analysis is discussed.

  16. An analysis of 100 MeV F 8+ ion and 50 MeV Li 3+ ion irradiation effects on silicon NPN rf power transistors

    NASA Astrophysics Data System (ADS)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Prabhakara Rao, Y. P.; Tripati, Ambuj; Revannasiddaiah, D.

    2010-08-01

    The dc characteristics exhibited by NPN power transistors are studied systematically before and after irradiation by 100 MeV F 8+ ions and 50 MeV Li 3+ ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current (Δ IB= IBpost- IBpre), dc current gain ( hFE), transconductance ( gm), and collector-saturation current ( ICsat) were studied before and after irradiation. The damage factors ( k) for hFE were calculated for ion irradiated transistors using Messenger-Spratt relation. The base current ( IB) was found to increase significantly after ion irradiation and this in turn decreases the hFE of the transistors. The gm decreases significantly after ion irradiation. Moreover, the output characteristics of irradiated devices also show that the collector current ( IC) in the saturation region ( ICsat) decrease with increase in ion dose. The observed change in these characteristics may be due to the ion induced generation-recombination (G-R) centers in emitter-base (E-B) spacer oxide and the ion induced point defects and their complexes in the transistor structure.

  17. Radiation effects on silicon bipolar transistors caused by 3-10 MeV protons and 20-60 MeV bromine ions

    NASA Astrophysics Data System (ADS)

    Li, Xingji; Geng, Hongbin; Lan, Mujie; Liu, Chaoming; Yang, Dezhuang; He, Shiyu

    2010-03-01

    The current gain degradation in silicon NPN bipolar junction transistors (BJTs) was examined under irradiation with 3-10 MeV protons and 20-60 MeV bromine (Br) ions with various dose levels. To characterize the radiation damage of the NPN BJTs, the ionizing dose D i and displacement dose D d as a function of chip depth in the NPN BJTs were calculated for both the protons and Br ions with different energies. Based on the irradiation testing and calculated results, it is shown that the current gain degradation of NPN BJTs is sensitive to the ratio of D d/( D d+ D i) in the sensitive region given by protons and Br ions. The irradiation particles (protons and Br ions), which give larger D d/( D d+ D i) at a given total dose, would generate more severe damage to the NPN BJTs. The reciprocal of the gain variation as a function of the displacement dose was compared, showing that the Messenger-Spratt equation becomes relevant to describe the experimental data, when the ratio of the D d/( D d+ D i) are larger and the displacement dose are higher than a certain value.

  18. The calibration of photographic and spectroscopic films: The response of 2aO film to small dosages of alpha particles from 3/10th's rad to 8 rads at energy levels 153 MeV, 79 MeV and 47 MeV

    NASA Technical Reports Server (NTRS)

    Hammond, E. C., Jr.; Peters, Kevin; Stober, AL

    1984-01-01

    The 2aO film, pre-exposed to a series of neutral density filters which on development under standard conditions will produce the standard H-D curve for that film, were then exposed to Alpha paricles with a dose range of 3/10ths rads to 8 rads while varying the energy of the particles using 153 MeV, 70 MeV, and 47 MeV, respectively. An analysis of the film shows that the 3/10th rad dose produces the lowest optical density changes at 70 MeV and 47 MeV. While the optical density readings for the darker patterns seem to oscillate and decrease when exposed to radiation dosages of 3/10th rads to 8 rads.

  19. {sup {bold 6}}Li(vector)+{sup {bold 12}}C inelastic scattering at 30 and 50 MeV

    SciTech Connect

    Kerr, P.L.; Kemper, K.W.; Green, P.V.; Mohajeri, K.; Myers, E.G.; Schmidt, B.G.; Hnizdo, V.

    1996-09-01

    A complete set of analyzing powers (AP`s), {ital iT}{sub 11}, {ital T}{sub 20}, {ital T}{sub 21}, and {ital T}{sub 22}, for 50 MeV {sup 12}C({sup 6}Li(vector),{sup 6}Li) elastic scattering and inelastic scattering to the {sup 12}C(2{sup +}, 4.44 MeV), {sup 12}C(0{sup +}, 7.65 MeV), and {sup 12}C(3{sup {minus}}, 9.64 MeV) states over the center-of-mass (c.m.) angular range 10{degree}{endash}115{degree} is reported. In addition, cross sections for the excited states 3{sup +}(2.18 MeV), 2{sup +}(4.31 MeV), and 1{sup +}(5.65 MeV) of {sup 6}Li were measured by using the inverse-kinematics reaction {sup 6}Li({sup 12}C,{sup 12}C) at 100 MeV. A combined analysis of the new 50 MeV data and previous 30 MeV data has been carried out using the coupled-channels (CC) code FRESCO. The CC calculations use an optical potential with double-folded (DF) real central, Woods-Saxon imaginary central, and Thomas real spin-orbit (SO) potentials. Calculations include reorientation terms and coupling to the first three excited states of {sup 6}Li and the first two nonzerospin states of {sup 12}C. The {sup 6}Li coupling strengths were fixed by the measured {sup 6}Li excited-state cross sections. The elastic-scattering cross sections and A.P.`s are described well. The need for an explicit SO potential is apparent in the elastic and inelastic-scattering AP`s {ital iT}{sub 11}, more so at 30 MeV than at 50 MeV. The rank-2 AP`s up to 50{degree} c.m. arise mainly from ground-state reorientation effects. The DF potential normalization constant {ital N} approaches unity for the 50 MeV data. At both energies, the {sup 12}C(2{sup +}) cross sections are underestimated at large angles, and the description of the {sup 12}C(3{sup {minus}}) cross sections is poor in detail. The {sup 12}C(3{sup {minus}}) AP`s and the {sup 12}C(2{sup +}) {ital iT}{sub 11} are not reproduced at either energy. {copyright} {ital 1996 The American Physical Society.}

  20. A new 5 MeV-300 kW dynamitron for radiation processing

    NASA Astrophysics Data System (ADS)

    Galloway, R. A.; Lisanti, T. F.; Cleland, M. R.

    2004-09-01

    The high beam power required to deliver reasonably effective levels of X-rays for processing food and medical products has driven the development of a new high-power Dynamitron ® system. For many years, RDI accelerators have been providing up to 200 kW of DC electron beam power at energies up to 5.0 MeV. This new system, designed to operate at 300 kW of beam power at 5.0 MeV, is also capable of producing up to 75 mA of beam current when operating at lower voltages. Achieving this high power level and maintaining the high reliability that Dynamitrons are known for has required new designs offering lower power losses yielding higher efficiency and reducing stress in critical components. Improvements in beam control and optics add to the stability and reliability of the system providing a basis for a highly reliable high-power system.

  1. The response of CR-39 nuclear track detector to 1-9 MeV protons

    SciTech Connect

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Johnson, M. Gatu; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2011-10-28

    The response of CR-39 nuclear track detector (TasTrak®) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. The effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather than the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.

  2. The response of CR-39 nuclear track detector to 1-9 MeV protons

    SciTech Connect

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Gatu Johnson, M.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2011-10-15

    The response of CR-39 nuclear track detector (TasTrak) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. Effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather than the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.

  3. Plasma production for the 50 MeV plasma lens experiment at LBL

    SciTech Connect

    Leemans, W.; van der Geer, B.; de Loos, M.; Conde, M.; Govil, R.; Chattopadhyay, S.

    1994-06-01

    The Center for Beam Physics at LBL has constructed a Beam Test Facility (BTF) housing a 50 MeV electron beam transport line, which uses the linac injector from the Advanced Light Source, and a terawatt Ti:Al{sub 2}O{sub 3} laser system. The linac operates at 50 MeV and generates 15 ps long electron bunches containing a charge of up to 2 nC. The measured unnormalized beam emittance is 0.33 mm-mrad. These parameters allow for a comprehensive study of focusing of relativistic electron beams with plasma columns, in both the overdense and underdense regime (adiabatic and tapered lenses). A study of adiabatic and/or tapered lenses requires careful control of plasma density and scale lengths of the plasma. We present experimental results on the production of plasmas through resonant two-photon ionization, with parameters relevant to an upcoming plasma lens experiment.

  4. Probing MeV dark matter at low-energy e+e- colliders.

    PubMed

    Borodatchenkova, Natalia; Choudhury, Debajyoti; Drees, Manuel

    2006-04-14

    It has been suggested that the pair annihilation of dark matter particles chi with mass between 0.5 and 20 MeV into e+e- pairs could be responsible for the excess flux (detected by the INTEGRAL satellite) of 511 keV photons coming from the central region of our Galaxy. The simplest way to achieve the required cross section while respecting existing constraints is to introduce a new vector boson U with mass M(U) below a few hundred MeV. We point out that over most of the allowed parameter space, the process e+e--->U(gamma), followed by the decay of U into either an e+e- pair or an invisible (nu(-)nu or chi(-)chi) channel, should lead to signals detectable by current B-factory experiments. A smaller, but still substantial, region of parameter space can also be probed at the Phi factory DAPhiNE.

  5. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma Lei; Wang Yugang; Xue Jianming; Chen Qizhong; Zhang Weiming; Zhang Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat, and tomato coat) with different mass thickness were studied, together with Mylar for comparison. The energy loss and energy straggling of MeV H and He ions after penetrating the biological and Mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions; however, large deviation in energy straggling is observed between the measured results and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicted by the proposed formula.

  6. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma, Lie; Wang, Yugang; Xue, Jianming; Chen, Qizhong; Zhang, Weiming; Zhang, Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat and tomato coat) with different mass thickness were studied, together with mylar for comparison, in this work. The energy loss and energy straggling of MeV H and He ions after penetrating from the biological and mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions, however, large deviation in energy straggling is observed between the measured result and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicated by the proposed formula.

  7. MeV ion beam interaction with polymer films containing cross-linking agents

    SciTech Connect

    Evelyn, A. L.

    1999-06-10

    Polymer films containing cross linking enhancers were irradiated with MeV alpha particles to determine the effects of MeV ion beam interaction on these materials. The contributed effects from the electronic and nuclear stopping powers were separated by irradiating stacked thin films of polyvinyl chloride (PVC), polystyrene (PS) and polyethersulfone (PES). This layered system allowed most of the effects of the electronic energy deposited to be experienced by the first layers and the last layers to receive most of the effects of the nuclear stopping power. RGA, Raman microprobe analysis, RBS and FTIR measured changes in the chemical structures of the irradiated films. The characterization resolved the effects of the stopping powers on the PVC, PS and PES and the results were compared with those from previously studied polymers that did not contain any cross linking agents.

  8. A study of the effects of MeV alpha particles in PE and PVDC

    SciTech Connect

    Evelyn, A.L.; Ila, D.; Zimmerman, R.L.; Bhat, K.; Poker, D.B.; Hensley, D.K.

    1997-02-01

    We have mapped and studied the effects of MeV alpha-particle bombardment in polyvinylidene chloride (PVDC) and polyethylene (PE). We used 3.5 and 5.0 MeV alpha-particle incident beams and stacked polymer films to separate the contributing effects of the electronic ({var_epsilon}{sub e}) and nuclear ({var_epsilon}{sub n}) stopping powers. The electrical conductance and change in the chemical structures were measured by direct resistivity measurement, Raman microprobe, RBS and FTIR. The results indicate significant differences in the ({var_epsilon}{sub e}) and ({var_epsilon}{sub n}) effects at higher alpha-particle bombardment fluences. {copyright} {ital 1997 American Institute of Physics.}

  9. A new proton fluence model for E greater than 10 MeV

    NASA Technical Reports Server (NTRS)

    Feynman, Joan; Armstrong, T. P.; Dao-Gibner, L.; Silverman, S.

    1988-01-01

    Researchers describe a new engineering model for the fluence of protons with energies greater than 10 MeV. The data set used is a combination of observations made primarily from the Earth's surface between 1956 and 1963 and observations made from spacecraft in the vicinity of Earth between 1963 and 1985. With this data set we find that the distinction between ordinary proton events and anomalously large proton events made in earlier work disappears. The greater than 10 MeV fluences at 1 AU calculated with the new model are about twice those expected on the basis of models now in use. In contrast to earlier models, results do not depend critically on the fluence from any one event.

  10. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    SciTech Connect

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  11. Modification & alignment of beam line of 10 MeV RF electron beam accelerator

    NASA Astrophysics Data System (ADS)

    Barnwal, R.; Ghodke, S. R.; Bhattacharjee, D.; Kumar, M.; Jayaprakash, D.; Chindarkar, A. R.; Mishra, R. L.; Dolas, S.; Kulkarni, S. Y.; Kumar, M.; P, Dixit K.; S, Acharya; Barje, S. R.; Lawangare, N. K.; C, Saroj P.; Nimje, V. T.; Chandan, S.; Tillu, A. R.; V, Sharma; Chavan, R. B.; V, Yadav; P, Roychowdhury; Mittal, K. C.; Chakravarthy, D. P.; Ray, A. K.

    2008-05-01

    A 10 MeV, 10 kW RF industrial Electron linac designed and developed at BARC is installed at the Electron Beam Center Kharghar, Navi Mumbai. The entire RF accelerator assembly consists of Electron gun, RF source, RF linac structure, Beam diagnostic chamber, Drift tube, Scanning magnet, Beam sensing aperture, Scan horn, and is spread over two floors at EBC. The paper discusses in detail about the alignment procedure adopted for the equipments of 10 MeV RF beamline. The complete electron beamline will be maintained under ultra high vacuum of the order of 10-7 torr. The paper discusses about the present problem of alignment, measurement technique of alignment, reason for misalignment, possible ways to solve the problem, equipment used for alignment, supports & arrestors, verification of alignment under vacuum

  12. Analysis of the pp analyzing-power data at 50.04 Mev

    NASA Astrophysics Data System (ADS)

    Stoks, V. G. J.; de Swart, J. J.

    1990-07-01

    The recent, very accurate proton-proton analyzing-power measurements by the Zürich group at tlab = 50.04 MeV are analyzed. We show that in order to arrive at a proper description of these data, the magnetic-moment interaction has to be included in all partial waves. It is also shown that some of the approximations made in the literature, when trying to incorporate this magnetic-moment interaction, are inadequate. From these beautiful data one can now determine quite accurately the phase shifts at 50 MeV. We compare our results with the phase shifts found in other phase-shift analyses. Some of our phase shifts differ by 6-9 standard deviations from these analyses. Finally, we compare the predictions of some well-known nucleon-nucleon potential models with these high-precision data.

  13. A three-dimensional study of 30- to 300-MeV atmospheric gamma rays

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.

    1974-01-01

    A three-dimensional study of atmospheric gamma rays with energy greater than 30 MeV has been carried out. A knowledge of these atmospheric secondaries has significant applications to the study of cosmic gamma rays. For detectors carried on balloons, atmospherically produced gamma rays are the major source of background. For satellite detectors, atmospheric secondaries provide a calibration source. Experimental results were obtained from four balloon flights from Palestine, Texas, with a 15 cm by 15 cm digitized wire grid spark chamber. The energy spectrum for downward-moving gamma rays steepens with increasing atmospheric depth. Near the top of the atmosphere, the spectrum steepens with increasing zenith angle. A new model of atmospheric secondary production has calculated the depth, the energy, and the zenith angle dependence of gamma rays above 30 MeV, using a comprehensive three-dimensional Monte Carlo model of the nucleon-meson-electromagnetic cascade.

  14. The New Sorgentina Fusion Source-NSFS: 14 MeV neutrons for fusion and beyond

    NASA Astrophysics Data System (ADS)

    Pietropaolo, A.; Console Camprini, P.; Agostini, P.; Amendola, R.; Angelone, M.; Bernardi, D.; Bruni, F.; Capogni, M.; Colognesi, D.; Faccini, R.; Filabozzi, A.; Flammini, D.; Fiori, F.; Frisoni, M.; Grazzi, F.; Pillon, M.; Pizzuto, A.; Quintieri, L.; Sacchetti, F.; Valente, P.

    2016-09-01

    The importance of the design for the realization of an intense 14 MeV neutron facility devoted to test and validate materials suitable for harsh neutron environments, such as a fusion reactor, is well established. The “New Sorgentina” Fusion Source (NSFS) is a project that proposes an intense D-T 14 MeV neutron source achievable with T and D ion beams impinging on 2 m radius rotating targets. NSFS may produce about 1015 n/s at the target and has to be intended as an European facility that maybe realized in a few years, once provided a preliminary technological program devoted to the operation of the ion source in continuous mode, target heat loading/removal, target and tritium handling, inventor as well as site licensing. In this contribution, the main characteristics of NSFS project will be presented and its possible use as a multipurpose facility outlined.

  15. Modification of ROSPEC to cover neutrons from thermal to 18 MeV.

    PubMed

    Ing, H; Djeffal, S; Clifford, T; Li, L; Noulty, R; Machrafi, R

    2007-01-01

    Rotating Spectrometer (ROSPEC) is a neutron spectrometer designed to measure neutron energy distributions, and provide accurate neutron dosimetry. It is a completely self-contained unit and measures neutron energy via recoiling protons in gas proportional counters. Each of the four original gas counters is dedicated to a particular neutron energy range dictated by sensitivity to gamma rays at the low energy end of the spectrum and by proton collisions with the counter walls at the high energy end. Introduced originally in 1992, ROSPEC has a proven operational record with a program of continued upgrades. The operating range of the original ROSPEC spans 50 keV-4.5 MeV. The range of the ROSPEC has now been extended down to include epithermal and thermal neutrons by adding two 2 in. (3)He counters. Also, an optional simple scintillation spectrometer was designed to extend the upper limit of ROSPEC up to 18 MeV.

  16. The response of CR-39 nuclear track detector to 1-9 MeV protons

    DOE PAGES

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Johnson, M. Gatu; Seguin, F. H.; Frenje, J. A.; et al

    2011-10-28

    The response of CR-39 nuclear track detector (TasTrak®) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. The effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather thanmore » the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.« less

  17. STATUS OF NEW 2.5 MEV TEST FACILITY AT SNS

    SciTech Connect

    Aleksandrov, Alexander V; Champion, Mark; Crofford, Mark T; Kang, Yoon W; Menshov, Alexander A; Roseberry, Jr., R Tom; Stockli, Martin P; Webster, Anthony W; Welton, Robert F; Zhukov, Alexander P

    2014-01-01

    A new 2.5MeV beam test facility is being built at SNS. It consists of a 65 keV H- ion source, a 2.5MeV RFQ, a beam line with various beam diagnostics and a 6 kW beam dump. The facility is capable of producing one-ms-long pulses at 60Hz repetition rate with up to 50mA peak current. The commissioning with reduced average beam power is planned for fall 2014 to verify operation of all systems. The full power operation is scheduled to begin in 2015. The status of the facility will be presented as well as a discussion of the future R&D program.

  18. The impact of two semiannual treatments with albendazole alone on lymphatic filariasis and soil-transmitted helminth infections: a community-based study in the Republic of Congo.

    PubMed

    Pion, Sébastien D S; Chesnais, Cédric B; Bopda, Jean; Louya, Frédéric; Fischer, Peter U; Majewski, Andrew C; Weil, Gary J; Boussinesq, Michel; Missamou, François

    2015-05-01

    Implementation of mass drug administration (MDA) with ivermectin plus albendazole (ALB) for lymphatic filariasis (LF) has been delayed in central Africa because of the risk of serious adverse events in subjects with high Loa loa microfilaremia. We conducted a community trial to assess the impact of semiannual MDA with ALB (400 mg) alone on LF and soil-transmitted helminth (STH) infections in the Republic of Congo. Evaluation at 12 months showed that ALB MDA had not significantly reduced Wuchereria bancrofti antigenemia or microfilaria (mf) rates in the community (from 17.3% to 16.6% and from 5.3% to 4.2%, respectively). However, the geometric mean mf count in mf-positive subjects was reduced from 202.2 to 80.9 mf/mL (60% reduction, P = 0.01). The effect of ALB was impressive in 38 subjects who were mf-positive at baseline and retested at 12 months: 37% had total mf clearance, and individual mf densities were reduced by 73.0%. MDA also dramatically reduced the hookworm infection rate in the community from 6.5% to 0.6% (91% reduction), with less impressive effects on Ascaris and Trichuris. These preliminary results suggest that semiannual community MDA with ALB is a promising strategy for controlling LF and STH in areas with coendemic loiasis. PMID:25758650

  19. The Impact of Two Semiannual Treatments with Albendazole Alone on Lymphatic Filariasis and Soil-Transmitted Helminth Infections: A Community-Based Study in the Republic of Congo

    PubMed Central

    Pion, Sébastien D. S.; Chesnais, Cédric B.; Bopda, Jean; Louya, Frédéric; Fischer, Peter U.; Majewski, Andrew C.; Weil, Gary J.; Boussinesq, Michel; Missamou, François

    2015-01-01

    Implementation of mass drug administration (MDA) with ivermectin plus albendazole (ALB) for lymphatic filariasis (LF) has been delayed in central Africa because of the risk of serious adverse events in subjects with high Loa loa microfilaremia. We conducted a community trial to assess the impact of semiannual MDA with ALB (400 mg) alone on LF and soil-transmitted helminth (STH) infections in the Republic of Congo. Evaluation at 12 months showed that ALB MDA had not significantly reduced Wuchereria bancrofti antigenemia or microfilaria (mf) rates in the community (from 17.3% to 16.6% and from 5.3% to 4.2%, respectively). However, the geometric mean mf count in mf-positive subjects was reduced from 202.2 to 80.9 mf/mL (60% reduction, P = 0.01). The effect of ALB was impressive in 38 subjects who were mf-positive at baseline and retested at 12 months: 37% had total mf clearance, and individual mf densities were reduced by 73.0%. MDA also dramatically reduced the hookworm infection rate in the community from 6.5% to 0.6% (91% reduction), with less impressive effects on Ascaris and Trichuris. These preliminary results suggest that semiannual community MDA with ALB is a promising strategy for controlling LF and STH in areas with coendemic loiasis. PMID:25758650

  20. rvec p + sup 13 rvec C elastic scattering at 500 MeV

    SciTech Connect

    Tanaka, N.

    1990-01-01

    For the first time, an elastic scattering experiment was performed at LAMPF using polarized protons and a polarized target nucleus ({rvec p} + {sup 13}{rvec C}). The analyzing powers (A{sub ooon}({Theta})) and (A{sub oonn}({Theta})) were measured using an incident beam energy of 500 MeV over the laboratory angular range of 10{degree}--30{degree}. Motivation for the experiment and some preliminary results and conclusions are presented. 12 refs., 7 figs.

  1. The Origin of the Cosmic Gamma-ray Background in the MeV Range

    NASA Astrophysics Data System (ADS)

    Ruiz-Lapuente, Pilar; The, Lih-Sin; Hartmann, Dieter H.; Ajello, Marco; Canal, Ramon; Röpke, Friedrich K.; Ohlmann, Sebastian T.; Hillebrandt, Wolfgang

    2016-04-01

    There has been much debate about the origin of the diffuse γ-ray background in the MeV range. At lower energies, AGNs and Seyfert galaxies can explain the background, but not above ≃0.3 MeV. Beyond ˜10 MeV blazars appear to account for the flux observed. That leaves an unexplained gap for which different candidates have been proposed, including annihilations of WIMPS. One candidate is Type Ia supernovae (SNe Ia). Early studies concluded that they were able to account for the γ-ray background in the gap, while later work attributed a significantly lower contribution to them. All those estimates were based on SN Ia explosion models that did not reflect the full 3D hydrodynamics of SN Ia explosions. In addition, new measurements obtained since 2010 have provided new, direct estimates of high-z SN Ia rates beyond z ˜ 2. We take into account these new advances to see the predicted contribution to the gamma-ray background. We use here a wide variety of explosion models and a plethora of new measurements of SN Ia rates. SNe Ia still fall short of the observed background. Only for a fit, which would imply ˜150% systematic error in detecting SN Ia events, do the theoretical predictions approach the observed fluxes. This fit is, however, at odds at the highest redshifts with recent SN Ia rate estimates. Other astrophysical sources such as flat-spectrum radio quasars do match the observed flux levels in the MeV regime, while SNe Ia make up to 30%-50% of the observed flux.

  2. Scattering of {sup 8}He on {sup 208}Pb at 22 MeV

    SciTech Connect

    Marquinez-Duran, G.; Sanchez-Benitez, A. M.; Martel, I.; Berjillos, R.; Duenas, J. A.; Parkar, V. V.; Acosta, L.; Rusek, K.; Alvarez, M. A. G.; Gomez-Camacho, J.; Borge, M. J. G.; Cruz, C.; Cubero, M.; Pesudo, V.; Tengblad, O.; Chbihi, A.; Fernandez-Garcia, J. P.; Moro, A. M.; Fernandez-Martinez, B.; Labrador, J. A.; and others

    2013-06-10

    The skin nucleus {sup 8}He is investigated by measuring the angular distribution of the elasticly scattered {sup 8}He and the {sup 6,4}He fragments produced in the collision with a {sup 208}Pb target at 22 MeV, just above the Coulomb barrier. The experiment was carried out at SPIRAL/GANIL in 2010. Here we present preliminary results for the elastic scattering.

  3. Comments on (n, charged particle) reactions at E/sub n/ = 14 MeV

    SciTech Connect

    Haight, R.C.

    1984-01-01

    The study of charged particles produced by bombarding materials with 14 MeV neutrons is important for the development of fusion reactors and for biomedical applications as well as for the basic understanding of nuclear reactions. Several experimental techniques for investigating these reactions are discussed here. The interpretation of the data requires the consideration of several possible reaction mechanisms including equilibrium and preequilibrium particle emission and, for light nuclei, sequential particle emission, final state interactions, and the effect of resonances. 17 references.

  4. Voltage holding study of 1 MeV accelerator for ITER neutral beam injector

    SciTech Connect

    Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Dairaku, M.; Takemoto, J.; Tobari, H.; Tsuchida, K.; Yamanaka, H.; Watanabe, K.; Kojima, A.; Hanada, M.; Sakamoto, K.; Inoue, T.

    2012-02-15

    Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration, which leads to discharge initiation at lower voltage. To reduce the electric field concentration in the MeV accelerator, gaps between the grid supports were expanded and curvature radii at the support corners were increased. After the modifications, the accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. However, the beam energy was still limited at a level of 900 keV with a beam current density of 150 A/m{sup 2} (346 mA) where the 3 x 5 apertures were used. Measurement of the beam profile revealed that deflection of the H{sup -} ions was large and a part of the H{sup -} ions was intercepted at the acceleration grid. This causes high heat load on the grids and the breakdowns during beam acceleration. To suppress the direct interception, new grid system was designed with proper aperture displacement based on a 3D beam trajectory analysis. As the result, the beam deflection was compensated and the voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A/m{sup 2} (427 mA), which is close to the requirement of ITER accelerator (1 MeV, 200 A/m{sup 2}).

  5. Isotopic production cross sections in proton-nucleus collisions at 200 MeV

    SciTech Connect

    Machner, H.; Aschman, D.G.; Steyn, D.; Baruth-Ram, K.; Carter, J.; Sideras-Haddad, E.; Sellschop, J.P.F.; Cowley, A.A.; Goldenbaum, F.; Nangu, B.M.; Spoelstra, B.; Pilcher, J.V.; Smit, F.D.

    2006-04-15

    Intermediate-mass fragments from the interaction of {sup 27}Al, {sup 59}Co, and {sup 197}Au with 200-MeV protons were measured in an angular range from 20 deg. to 120 deg. in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double-differential cross sections, energy-differential cross sections, and total cross sections were extracted.

  6. Nuclear multifragmentation by 700–1500 MeV photons: New data of GRAAL experiment

    SciTech Connect

    Nedorezov, V. G. Lapik, A. M.; Collaboration: GRAAL Collaboration

    2015-12-15

    The cross sections of carbon nucleus photodisintegration into protons and neutrons with high multiplicity for photon energies from 700 to 1500 MeV were measured. The experiment was performed at the tagged photon beam of the GRAAL setup using the wide-aperture detector LAGRANγE. It was shown that multifragmentation up to complete disintegration into separate nucleons is initiated by elementary reactions of meson photoproduction with a subsequent intranuclear cascade.

  7. Accelerator driven system based on plutonium subcritical reactor and 660 MeV phasotron

    NASA Astrophysics Data System (ADS)

    Arkhipov, V. A.; Barashenkov, V. S.; Buttsev, V. S.; Chultem, D.; Dudarev, S. Yu.; Furman, V. I.; Gudowski, W.; Janczyszyn, J.; Maltsev, A. A.; Onischenko, L. M.; Pogodajev, G. N.; Polanski, A.; Popov, Yu. P.; Puzynin, I. V.; Sissakian, A. N.; Taczanowski, S.

    1999-11-01

    The proposal presents a PLUTONIUM BASED ENERGY AMPLIFIER TESTING CONCEPT which employs a plutonium subcritical assembly and a 660 MeV proton accelerator, operating in the the JINR (Dubna, Russia). To make the present conceptual design of the Plutonium Energy Amplifier we have chosen a nominal unit capacity of 20 kW (thermal). This corresponds to the multiplication coefficient keff between 0.94 and 0.95 and the energetic gain about 20.

  8. Biomedical user facility at the 400-MeV Linac at Fermilab

    SciTech Connect

    Chu, W.T.

    1993-12-01

    In this paper, general requirements are discussed on a biomedical user facility at the Fermilab`s 400-MeV Linac, which meets the needs of biology and biophysics experiments, and a conceptual design and typical operations requirements of the facility is presented. It is assumed that no human patient treatment will take place in this facility. If human patients were treated, much greater attention would have to be paid to safeguarding the patients.

  9. Impurity/defect interactions during MeV Si{sup +} ion implantation annealing

    SciTech Connect

    Agarwal, A.; Koveshnikov, S.; Christensen, K.

    1995-08-01

    Ion implantation of dopant atoms at MeV energies is currently being explored in several integrated circuit device manufacturing processes. MeV implantation offers immediate advantages such as vertical well modulation, latch-up protection, device structure isolation, and reduced temperature processing. Simultaneously, it presents an opportunity to achieve {open_quotes}proximity{close_quotes} gettering of impurities from the active device region by placing high impurity solubility and/or secondary defect gettering sites within microns of the surface. If the MeV implanted species is a dopant ion, all three gettering mechanisms, i.e, segregation, relaxation and injection, can be involved in the gettering process, complicating the analysis and optimization of the process. However, investigation of gettering using non-dopant Si{sup +} ion damage allows the relaxation component of the gettering process to be isolated and examined separately. In general, gettering is verified by a reduction in impurity concentration in the region of interest, usually the device region, and/or a build-up of concentration/precipitation in a non-device sink region. An alternate and more meaningful approach is to use simple devices as materials characterization probes via changes in the electrical activity of the gettering sites. Device space charge probes also allow the evolution of the defect sites upon contamination to be tracked. We report here results of the electrical, structural, and chemical characterization of MeV implanted Si{sup +} damage using Deep Level Transient Spectroscopy (DLTS), Transmission Electron Microscopy (TEM), and Secondary Ion Mass Spectroscopy (SIMS). The damage has been characterized both as a function of annealing from 600 to 1100{degrees}C for 1 hr, and after contamination with Fe followed by low temperature gettering annealing.

  10. Irradiation Effects of 22 and 240 MeV Protons on Several Transistors and Solar Cells

    NASA Technical Reports Server (NTRS)

    Hulten, W. C.; Honaker, W. C.; Patterson, John L.

    1961-01-01

    The work covered in this report has been directed toward the investigation of the irradiation effects of 22 and 240 MeV protons on several transistors, solar cells, resistors, and condensers to be used in the space radiation environment. The experimental data indicated definite detrimental effects on transistors and solar cells but no apparent effects on the types of resistors and condensers tested. The detrimental effects are of two distinct types: transient and permanent.

  11. Gamma radiation from the Crab nebula above 35 MeV

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    Electromagnetic radiation from the Crab nebula were observed, showing that the Crab is unique among strong X-ray sources in that major component in the low energy range (1 to 10 KeV) shows little or no temporal variation. Observations of the Crab above 35 MeV were made with the high energy gamma ray telescope flown on SAS-2. The detector and technique are described in detail.

  12. Direct experimental reconstruction of the pp elastic scattering matrix at 579 MeV

    SciTech Connect

    Aprile, E.; Eisenegger, C.; Hausammann, R.; Heer, E.; Hess, R.; Lechanoine-Leluc, C.; Leo, W.R.; Morenzoni, S.; Onel, Y.; Rapin, D.; Mango, S.

    1981-04-20

    We have made, for the first time, a direct reconstruction of the pp elastic scattering matrix at 579 MeV from a series of experiments performed with a polarized beam line. Fifteen observables consisting of the polarization, two-spin correlation and transfer parameters, and three-spin parameters were measured at seven angles between 66/sup 0/ and 90/sup 0/ center of mass. The experimental results and reconstructed amplitudes are presented and compared to a phase-shift analysis.

  13. Celestial diffuse gamma radiation above 30 MeV observed by SAS-2

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    The Small Astronomy Satellite (SAS)-2, launched on November 15, 1972, carried into orbit a 32-deck magnetic-core digitized spark chamber gamma ray telescope to study celestial gamma radiation in the energy range above 30 MeV. In the study of several regions with b sub 2 15 deg, a finite, diffuse flux of gamma rays with a steep energy spectrum in the energy region from 35 to 200 MeV is observed. Representing the energy spectrum by a power law of the form dJ/dE = AE to - alpha power over this energy range, alpha is found along with the integral flux above 100 MeV. Combining this result with existing low energy gamma ray data yields an energy spectrum which is not a simple power law in energy, as in the X-ray region, but which demonstrates first an increase and then a decrease in slope, consistent within uncertainties with that predicted by cosmological theories, including the continuous production of high energy gamma rays primarily from neutral pi mesons throughout the history of the universe.

  14. Linac-beam characterizations at 600 MeV using optical transition radiation diagnostics

    NASA Astrophysics Data System (ADS)

    Lumpkin, A. H.; Berg, W. J.; Yang, B. X.; White, M.

    1998-12-01

    Selected optical diagnostics stations were upgraded in anticipation of low-emittance, bright electron beams from a thermionic rf gun or a photoelectric rf gun on the Advanced Photon Source (APS) injector linac. The upgrades include the installation of optical transition radiation (OTR) screens, transport lines, and cameras for use in transverse beam size measurements and longitudinal profile measurements. Using beam from the standard thermionic gun, tests were done at 50 MeV and 400 to 650 MeV. Data were obtained on the limiting spatial (σ˜200 μm) and temporal resolutions (300 ms) of the Chromox (Al2O3:Cr) screen (250 μm thick) in comparison to the OTR screens. Both charge-ecoupled device (CCD) and charge-injection device (CID) video cameras were used, as well as a Hamamatsu C5680 synchroscan streak camera operating at a vertical deflection rate of 119.0 MHz (the 24th subharmonic of the S-band 2856 MHz frequency). Beam transverse sizes as small as σx=60 μm for a 600 MeV beam and micropulse bunch lengths of στ<3 ps have been recorded for macropulse-averaged behavior with charges of about 2 to 3 nC per macropulse. These techniques are applicable to linac-driven, fourth-generation light source R&D experiments, including the APS's SASE FEL experiment.

  15. μCF based 14 MeV intense neutron source

    NASA Astrophysics Data System (ADS)

    Anisimov, V. V.; Cavalleri, E.; Karmanov, F. I.; Konobeyev, A. Yu.; Latysheva, L. N.; Ponomarev, L. I.; Pshenichnov, I. A.; Slobodtchouk, V. I.; Vecchi, M.

    1999-06-01

    Results of a design study for an advanced scheme of a μCF based 14 MeV intense neutron source for test material irradiation including the liquid lithium primary target and a low temperature liquid deuterium-tritium (D-T) mixture as a secondary target are presented. According to this scheme negative pions are produced inside a 150-cm-long 0.75-cm-radius lithium target. Pions and muons resulting from the pion decay in flight are collected in the backward direction and stopped in the D-T mixture. The fusion chamber has the shape of a 10-cm-radius sphere surrounded by two 0.03-cm-thickness titanium shells. Assuming 100 fusions per muon in this scheme one can produce 14-MeV neutrons with a source strength up to 1017 n/s. A neutron flux of up to 1014 n/cm2/s can be achieved in a test volume of about 2.5 l and on the surface of about 350 cm2. The results of the thermophysical and thermomechanical analysis show that the technological limits are not exceeded. This source has the advantage of producing the original 14 MeV fusion spectrum without tails, isotropically into a 4π solid angle, contrary to the d-Li stripping neutron source.

  16. Measurement of Ay for the pd Breakup Reaction at 250 MeV

    SciTech Connect

    Maeda, Y.; Uesaka, T.; Kawabata, T.; Suda, K.; Sasamoto, Y.; Sakaguchi, S.; Sakai, H.; Yako, K.; Sasano, M.; Noji, S.; Hatanaka, K.; Tamii, A.; Shimizu, Y.; Takechi, M.; Tameshige, Y.; Matsubara, H.; Sagara, K.; Wakasa, T.; Dozono, M.; Ihara, E.

    2007-06-13

    From the recent studies, it has been found that the differential cross sections of the elastic Nd scattering at the energy below 150 MeV can be well reproduced by incorporating the 3NF in the Faddeev calculation based on modern nucleon-nucleon (NN) interactions. On the other hand, the differential cross sections of nd and pd at 250 MeV show large discrepancies between the data and the Faddeev calculations with 3NF. It indicates the presence of the missing features of the three nucleon system at this energy region. For the next step of the 3NF study, we measured the vector analyzing power Ay and the differential cross sections for the 2H(p, pp)n breakup reaction at 250 MeV. The experiment was carried out by detecting two protons in the final state with using the double-armed spectrometer Grand Raiden (GR) and Large Acceptance Spectrometer (LAS) at Research Center for Nuclear Physics (RCNP). These data provide important information on the 3NF effects and make a discrimination between 3NF models.

  17. Design study of a 9 MeV compact cyclotron system for PET

    NASA Astrophysics Data System (ADS)

    Lee, Byeong-No; Shin, Seung-Wook; Song, Hoseung; Kim, Hyun-Wook; Chai, Jong-Seo

    2013-06-01

    A cyclotron is an accelerator which can be applied to both cancer diagnosis and treatment. Among commercially sold cyclotrons, the major energy is used for positron emission tomography (PET) ranges from 10 to 20 MeV. In this research, 9 MeV compact cyclotron for PET was designed. The research was conducted on the response cross section and the yield for the energy distribution to decide the design features. Also, it was determined the specifications on the basis of the fluoro-deoxy-glucose (FDG) maximum dose. The machine, which has a 20 uA beam current, is designed to be installed in small-to-medium-sized hospitals in local cities because of its relatively light weight (6 tons). This compact cyclotron, which provides 9-MeV proton beams, is composed of a azimuthally varying field (AVF) electromagnet, 83-MHz RF systems with a 20 kW amplifier, a panning ion gauge (PIG) type ion-source for negative hydrogen, and a double-stage high-vacuum system. The basic model design was done by using 3-D CAD program, CATIA and all the field calculations were performed using commercial electromagnetic field analysis code, OPERA-3D TOSCA. From this research, we expect a time reduction for FDG production, a decrease of radioactive exposure for workers, and an equipment cost reduction.

  18. 1 MeV, 10 kW DC electron accelerator for industrial applications

    NASA Astrophysics Data System (ADS)

    Nayak, B.; Acharya, S.; Bhattacharjee, D.; Bakhtsingh, R. I.; Rajan, R.; Sharma, D. K.; Dewangan, S.; Sharma, V.; Patel, R.; Tiwari, R.; Benarjee, S.; Srivastava, S. K.

    2016-03-01

    Several modern applications of radiation processing like medical sterilization, rubber vulcanization, polymerization, cross-linking and pollution control from thermal power stations etc. require D.C. electron accelerators of energy ranging from a few hundred keVs to few MeVs and power from a few kilowatts to hundreds of kilowatts. To match these requirements, a 3 MeV, 30 kW DC electron linac has been developed at BARC, Mumbai and current operational experience of 1 MeV, 10 kW beam power will be described in this paper. The LINAC composed mainly of Electron Gun, Accelerating Tubes, Magnets, High Voltage source and provides 10 kW beam power at the Ti beam window stably after the scanning section. The control of the LINAC is fully automated. Here Beam Optics study is carried out to reach the preferential parameters of Accelerating as well as optical elements. Beam trials have been conducted to find out the suitable operation parameters of the system.

  19. The 2-MEV model: Constancy of adolescent environmental values within an 8-year time frame

    NASA Astrophysics Data System (ADS)

    Bogner, F. X.; Johnson, B.; Buxner, S.; Felix, L.

    2015-08-01

    The 2-MEV model is a widely used tool to monitor children's environmental perception by scoring individual values. Although the scale's validity has been confirmed repeatedly and independently as well as the scale is in usage within more than two dozen language units all over the world, longitudinal properties still need clarification. The purpose of the present study therefore was to validate the 2-MEV scale based on a large data basis of 10,676 children collected over an eight-year period. Cohorts of three different US states contributed to the sample by responding to a paper-and-pencil questionnaire within their pre-test initiatives in the context of field center programs. Since we used only the pre-program 2-MEV scale results (which is before participation in education programs), the data were clearly unspoiled by any follow-up interventions. The purpose of analysis was fourfold: First, to test and confirm the hypothesized factorized structure for the large data set and for the subsample of each of the three states. Second, to analyze the scoring pattern across the eight years' time range for both preservation and utilitarian preferences. Third, to investigate any age effects in the extracted factors. Finally, to extract suitable recommendations for educational implementation efforts.

  20. New COMPTEL results on pulsar studies at MeV energies

    NASA Technical Reports Server (NTRS)

    Hermsen, W.; Kuiper, L.; Schoenfelder, V.; Strong, A. W.; Bennett, K.; Much, R.; McConnell, M.; Ryan, J.; Carraminana, A.

    1997-01-01

    The Compton telescope (COMPTEL) onboard the Compton Gamma Ray Observatory (CGRO) detected the pulsar PSR B1951-32 at MeV energies, and found indications of a signal from PSR B0656+14. In the combined spectra from COMPTEL and the energetic gamma ray experiment telescope (EGRET) onboard CGRO, it can be seen that the maximum luminosities of these objects are reached in the COMPTEL energy range. These spectra can be compared with those from four other pulsars observed in MeV energies with COMPTEL. The spectral properties of five of the six pulsars, Vela, PSR B1509-58, PSR B1951-32 and PSR B0656+14, require breaks and bends at MeV energies. The sixth pulsar, the Crab pulsar, approximately follows a power law flux relation from keV to GeV energies. It is concluded that this spectral behavior may play a role in the discrimination between current gamma ray emission models.

  1. Trends and applications for MeV electrostatic ion beam accelerators

    NASA Astrophysics Data System (ADS)

    Norton, G. A.; Stodola, S. E.

    2014-08-01

    The 1970s into the 1980s saw a major broadening of applications for electrostatic accelerators. Prior to this time, all accelerators were used primarily for nuclear structure research. In the 70s there was a significant move into production ion implantation with the necessary MeV ion beam analysis techniques such as RBS and ERD. Accelerators are still being built for these materials analysis techniques today. However, there is still a great ongoing expansion of applications for these machines. At the present time, the demand for electrostatic accelerators is near an all time high. The number of applications continues to grow. This paper will touch on some of the current applications which are as diverse as nuclear fission reactor developments and pharmacokinetics. In the field of nuclear engineering, MeV ion beams from electrostatic accelerators are being used in material damage studies and for iodine and actinide accelerator mass spectrometry (AMS). In the field of pharmacokinetics, electrostatic MeV accelerators are being used to detect extremely small amounts of above background 14C. This has significantly reduced the time required to reach first in human studies. These and other applications will be discussed.

  2. Ion desorption from frozen H 2O irradiated by MeV heavy ions

    NASA Astrophysics Data System (ADS)

    Collado, V. M.; Farenzena, L. S.; Ponciano, C. R.; Silveira, E. F. da; Wien, K.

    2004-10-01

    Nitrogen (0.13-0.85 MeV) and 252Cf fission fragments (˜65 MeV) beams are employed to sputter positive and negative secondary ions from frozen water. Desorption yields are measured for different ice temperatures and projectile energies. Target surface is continuously refreshed by condensed water while the target temperature varies and ice thickness changes. In both projectile energy ranges, the preferentially ejected ions are H +, H2+ and (H 2O) nH +-cluster ions. The yields of the corresponding negative ions H - and (H 2O) nO - or (H 2O) nOH - are 1-2 orders of magnitude lower. The (H 2O) nH + desorption yields decrease exponentially as the cluster size, n, increases. In the low energy range, the desorption of positive ion clusters may occur in a two-step process: first, desorption of preformed H 2O clusters and, then, ionization by H + or H 3O + capture. For 0.81 MeV N + projectile ions, the cluster ion emission contributes with 0.05% to the total H 2O desorbed yield. There are indications that emission of the (H 2O) nH + disappears for an electronic energy loss lower than 20 eV/Å. For the high energy range, desorption of small ion clusters is particularly enhanced, revealing that a fragmentation process also exists.

  3. ({ital p},{ital d}) reaction on {sup 62}Ni at 65 MeV

    SciTech Connect

    Matoba, M.; Kurohmaru, K.; Iwamoto, O.; Nohtomi, A.; Uozumi, Y.; Sakae, T.; Koori, N.; Ohgaki, H.; Ijiri, H.; Maki, T.; Nakano, M.; Sen Gupta, H.M.

    1996-04-01

    The {sup 62}Ni({ital p},{ital d}){sup 61}Ni reaction has been studied with 65 MeV polarized protons. Angular distributions of the differential cross section and analyzing power have been measured for neutron hole states in {sup 61}Ni up to an excitation energy of 7 MeV. The data analysis with a standard distorted-wave Born approximation theory provides transferred angular momenta {ital l} and {ital j} and spectroscopic factors for several strongly excited states. The 1{ital f}{sub 7/2} hole state spreads largely in the excitation energy region of 2{endash}6 MeV, while the 1{ital f}{sub 5/2}, 2{ital p}{sub 3/2}, and 2{ital p}{sub 1/2} hole states into only 2{endash}4 levels. The strength function of the 1{ital f}{sub 7/2} hole state is analyzed with an asymmetrical Lorentzian function. The damping mechanism of the single hole states is discussed. {copyright} {ital 1996 The American Physical Society.}

  4. A 0. 5 to 3. 0 MeV monoenergetic positron beam

    SciTech Connect

    Huomo, H.; AsokaKumar, P.; Henderson, S.D.; Phlips, B.F.; Mayer, R.; McDonough, J.; Hacker, H.; McCorkle, S.; Schnitzenbaumer, P.; Greenberg, J.S.

    1988-01-01

    An adjustable, 0.5--3 MeV monoenergetic positron beam has been constructed at Brookhaven. Currently a /sup 22/Na source with a W(100) foil transmission moderator produces a 1.1 mm FWHN beam with an intensity of 3/times/10/sup 5/ e/sup +//sec at a target located downstream from the accelerator. The divergence of the beam is less than 0.1/degree/ at 2.2 MeV energy. A SOA gun with 2 lens transport system brings the beam to a focus at the entrance of an electrostatic 3 MeV Dynamitron accelerator. The post acceleration beam transport system comprises 3 focusing solenolds, 4 sets of steering magnets and a 90/degree/ double focusing bending magnet. The beam energy spread at the target is <1 keV FWHN deduced from the beam size. Below we describe the positron extraction optics and acceleration, the construction of the beamline and the beam diagnostic devices. The salient beam parameters are listed at the end of this paper. 2 refs., 3 figs., 1 tab.

  5. Two nucleon systems at mπ~450MeV from lattice QCD

    DOE PAGES

    Orginos, Kostas; Parreño, Assumpta; Savage, Martin J.; Beane, Silas R.; Chang, Emmanuel; Detmold, William

    2015-12-23

    Nucleon-nucleon systems are studied with lattice quantum chromodynamics at a pion mass ofmore » $$m_\\pi\\sim 450~{\\rm MeV}$$ in three spatial volumes using $n_f=2+1$ flavors of light quarks. At the quark masses employed in this work, the deuteron binding energy is calculated to be $$B_d = 14.4^{+3.2}_{-2.6} ~{\\rm MeV}$$, while the dineutron is bound by $$B_{nn} = 12.5^{+3.0}_{-5.0}~{\\rm MeV}$$. Over the range of energies that are studied, the S-wave scattering phase shifts calculated in the 1S0 and 3S1-3D1 channels are found to be similar to those in nature, and indicate repulsive short-range components of the interactions, consistent with phenomenological nucleon-nucleon interactions. In both channels, the phase shifts are determined at three energies that lie within the radius of convergence of the effective range expansion, allowing for constraints to be placed on the inverse scattering lengths and effective ranges. Thus, the extracted phase shifts allow for matching to nuclear effective field theories, from which low energy counterterms are extracted and issues of convergence are investigated. As part of the analysis, a detailed investigation of the single hadron sector is performed, enabling a precise determination of the violation of the Gell-Mann–Okubo mass relation.« less

  6. Simulation of electron behavior in PIG ion source for 9 MeV cyclotron

    NASA Astrophysics Data System (ADS)

    J. Mu, X.; Ghergherehchi, M.; H. Yeon, Y.; W. Kim, J.; S. Chai, J.

    2014-12-01

    In this paper, we focus on a PIG source for producing intense H-ions inside a 9 MeV cyclotron. The properties of the PIG ion source were simulated for a variety of electric field distributions and magnetic field strengths using a CST particle studio. After analyzing the secondary electron emission (SEE) as a function of both magnetic and electric field strengths, we found that for the modeled PIG geometry, a magnetic field strength of 0.2 T provided the best results in terms of the number of secondary electrons. Furthermore, at 0.2 T, the number of secondary electrons proved to be greatest regardless of the cathode potential. Also, the modified PIG ion source with quartz insulation tubes was tested in a KIRAMS-13 cyclotron by varying the gas flow rate and arc current, respectively. The capacity of the designed ion source was also demonstrated by producing plasma inside the constructed 9 MeV cyclotron. As a result, the ion source is verified as being capable of producing an intense H- beam and high ion beam current for the desired 9 MeV cyclotron. The simulation results provide experimental constraints for optimizing the strength of the plasma and final ion beam current at a target inside a cyclotron.

  7. Study of {sup 27}Al(n,x{gamma}) reactions up to a neutron energy of 400 MeV

    SciTech Connect

    Hitzenberger, H.; Pavlik, A.; Vonach, H.; Chadwick, M.B.; Haight, R.C.; Nelson, R.O.; Young, P.G.

    1994-06-01

    The prompt {gamma}-radiation from the interaction of fast neutrons with Al was measured using the white neutron beam of the WNR facility at the Los Alamos National Laboratory. Partial production cross sections for residual nuclei in the range from F to Al were measured from threshold up to 400 MeV by observing the most intense {gamma}-transitions between low lying levels of these nuclei. Two-dimensional neutron time-of-flight versus gamma pulse height spectra from the interaction of the neutrons with Al were observed after flight-paths of about 20 and 40 m with a high-purity Ge-detector. The neutron cross sections for prominent {gamma}-transitions in a large number of residual nuclei could be derived with typical uncertainties of 10--20% up to a neutron energy of 400 MeV. The energy resolution varies from {approx}0.2 MeV at 10 MeV to {approx}50 MeV at 400 MeV. In the low energy range (up to 60 MeV) the results are compared with nuclear model calculations using the code GNASH. A very good overall agreement is obtained without special adjustment of parameters.

  8. FTIR analysis of polyethylene terephthalate irradiated by MeV He+

    NASA Astrophysics Data System (ADS)

    Djebara, M.; Stoquert, J. P.; Abdesselam, M.; Muller, D.; Chami, A. C.

    2012-03-01

    The degradation induced by MeV He+ ions onto polyethylene terephthalate (PET) is investigated as a function of fluence and electronic stopping power (dE/dx)e. Stack samples of four 3.6 μm PET films are irradiated by 3.5 MeV He+ under vacuum and room temperature at fluence ranging from 1013 to 1.5 × 1015 He+ cm-2. The entrance energies range from 3.5 MeV for the front film to 0.573 MeV for the rear one at the beginning of the irradiation and the corresponding mean (dE/dx)e lie for pristine PET between 158 and 264 keV/μm. A Fourier transform infrared spectroscopy (FTIR) analysis is undertaken. The different stack films present similar damages with magnitude increase as the fluence goes up. Moreover, higher is the electronic stopping power (dE/dx)e more important is the damage. The evolution of the normalized integrated absorbance A(ϕ)/A0 of the internal reference 1410 cm-1 band as a function of the fluence ϕ presents a complex behavior characterized by a two-exponential decay associated to low and high fluence range. The analysis reveals clearly that the A(ϕ)/A0 of the characteristic benzene ring 1577 cm-1 band remains steady till fluence around 3 × 1014 He+ cm-2 and then decreases smoothly as fluence increases. The band appearing at 1610 cm-1, assigned to mono substituted benzene, presents an integrated absorbance A(ϕ) which rises progressively and levels off beyond a critical fluence around 4 × 1014 He+ cm-2. The cross section of the creation of the monosubstituted benzene lies between 3 × 10-15 and 6 × 10-15 cm2 for (dE/dx)e = 158 and 264 keV/μm, respectively. Drastic loss of crystallinity is induced by the MeV He+ ion irradiation in the polymer. The amorphization is monitored by the evolution of the specific bands of the trans and gauche ethylene glycol residue conformations. A sudden drop in the integrated absorbance of the 1340 cm-1 band which characterizes the trans conformation is observed at fluence around 2 × 1014 He+ cm-2. On the other hand, a

  9. Measurement of excitation function for 63Cu(n, p) 63Ni reaction up to En=15 MeV

    NASA Astrophysics Data System (ADS)

    Shibata, S.; Shibata, T.; Imamura, M.; Ohkubo, T.; Satoh, S.; Uwamino, Y.; Nogawa, N.; Baba, M.; Matsuyama, S.; Iwasaki, S.

    1999-01-01

    The excitation function for the 63Cu(n, p) 63Ni reaction were measured using neutrons produced by the T(p, n) reaction at En=˜1.5 MeV, D(d, n) at En=˜6.5 MeV and T(d, n) at En=˜14 MeV, respectively. Irradiations were performed using the dynamitron accelerator at the Fast Neutron Laboratory of Tohoku University. After irradiation, the nickel was separated by anion-exchange and solvent extraction. The 63Ni was measured by liquid scintillation method. The cross sections obtained were compared with the calculated values of JENDL-3.

  10. Search for narrow structures in the anti pp annihilation cross section from 1925 to 1955 MeV

    SciTech Connect

    Lowenstein, D I; Peaslee, D C; Bromberg, C

    1980-01-01

    The anti pp annihilation cross section has been measured over the CM energy range 1925 to 1955 MeV with an RMS resolution of +-2.5 MeV on the average. This search yields no evidence for narrow enhancements in the S(1936) region. Using an A + B/p dependent background, a two standard deviation upper limit of 9 mb-MeV is set for the integrated area of any resonance with mass between 1936 and 1942 and with width less than or equal to 4 MeV.

  11. Measurements of 15.11-MeV gamma-ray flux produced in the reactions C-12(p, p')-C-12*(15.11 MeV) and O-16(p, p' alpha)-C-12*(15.11 MeV)

    NASA Technical Reports Server (NTRS)

    Lapides, J. R.; Crannell, C. J.; Crannell, H.; Hornyak, W. F.; Seltzer, S. M.; Trombka, J. I.; Wall, N. S.

    1978-01-01

    The flux of 15.11 MeV gamma rays relative to the flux of 4.44 MeV gamma rays which are emitted from the corresponding states of C-12 are a sensitive measure of the spectrum of exciting particles in solar flares and other cosmic sources. Emission of 15.11 MeV gamma rays may result not only from the direct excitation of C-12 but also from the interaction O-16 (p,p' alpha) C-12* sup 15.11 MeV. Although the cross sections for the direct reaction was studied extensively, the cross section for the spallation interaction with O-16 is not reported in the literature. Preliminary measurements demonstrated the feasibility of measuring the production of 15.11 MeV gamma rays by proton interactions with O-16 using the University of Maryland cyclotron facility. For both carbon and oxygen targets the flux of 15.11 MeV gamma rays is being measured relative to the flux of 4.44 MeV gamma rays. The gamma ray emission from de-excitation of the giant dipole resonances is being measured.

  12. Single event upsets calculated from new ENDF/B-VI proton and neutron data up to 150 MeV

    SciTech Connect

    Chadwick, M.B.; Normand, E.

    1999-06-01

    Single-event upsets (SEU) in microelectronics are calculated from newly-developed silicon nuclear reaction recoil data that extend up to 150 MeV, for incident protons and neutrons. Calculated SEU cross sections are compared with measured data.

  13. Gamma rays of 1-30 MeV from the Vela Pulsar PSR 0833-45

    NASA Technical Reports Server (NTRS)

    Tumer, T.; Long, J.; Oneill, T.; Zych, A.; White, R. S.; Dayton, B.

    1983-01-01

    Results are reported for observations of gamma rays of 1-30 MeV from the Vela Pulsar PSR 0833 - 45 carried out with the UCR double scatter gamma ray telescope on a balloon launched from Alice Springs, Australia on November 10, 1981. An integrated flux of (5.3 + or - 1.3) x 10 to the -4th photons/sq cm/s is found for the Vela region above 2 MeV. This value, together with those for the energy intervals of 2-4, 4-7, and 7-15 MeV are in reasonable agreement with the power law found by COS-B at energies above 50 MeV. A sky contour map of the fluxes is shown.

  14. Neutron production in neutron-induced reactions at 96 MeV on 56Fe and 208Pb

    NASA Astrophysics Data System (ADS)

    Sagrado García, I. C.; Lecolley, J. F.; Lecolley, F. R.; Blideanu, V.; Ban, G.; Fontbonne, J. M.; Itis, G.; Lecouey, J. L.; Lefort, T.; Marie, N.; Steckmeyer, J. C.; Le Brun, C.; Blomgren, J.; Johansson, C.; Klug, J.; Orhn, A.; Mermod, P.; Olsson, N.; Pomp, S.; Osterlund, M.; Tippawan, U.; Prokofiev, A. V.; Nadel-Turonski, P.; Fallot, M.; Foucher, Y.; Guertin, A.; Haddad, F.; Vatre, M.

    2011-10-01

    Double-differential cross sections for neutron production were measured in 96-MeV neutron-induced reactions at The Svedberg Laboratory in Uppsala, Sweden. Measurements for Fe and Pb targets were performed using two independent setups: DECOI-DEMON, time-of-flight telescope dedicated to the detection of emitted neutrons with energies between a few and 50MeV and CLODIA-SCANDAL device devoted to measuring emitted neutrons with energies above 40MeV. Double-differential cross sections were measured for an angular range between 15 and 98 deg and with low-energy thresholds (≈2 MeV). Angular and energy distributions and total neutron emission cross sections have been obtained from those measurements. Results have been compared with predictions given by different models included in several transport codes (MCNPX, GEANT, TALYS, PHITS, and DYWAN) and with other experimental data (the EXFOR database).

  15. Elastic and inelastic neutron scattering from /sup 27/Al at 11, 14, and 17 MeV

    SciTech Connect

    Whisnant, C.S.; Dave, J.H.; Gould, C.R.

    1984-11-01

    Fast neutron scattering cross sections have been measured for /sup 27/Al using a neutron time-of-flight facility. Angular distributions were measured at angles from 20/sup 0/ to 160/sup 0/ in 5/sup 0/ increments, at incident neutron energies of 11, 14, and 17 MeV. Data are presented for elastic scattering and for inelastic scattering to the sum of the 0.84 and 1.01 MeV states, the 2.21 MeV state, and the sum of the 2.73, 2.98, and 3.00 MeV states. After correcting for compound nucleus effects, the elastic scattering cross sections are well reproduced by the spherical optical model using a linear energy dependence in the real well depth. The inelastic data are interpreted with a coupled channels calculation and the excited core model.

  16. Neutron total and scattering cross sections of /sup 6/Li in the few MeV region

    SciTech Connect

    Smith, A.; Guenther, P.; Whalen, J.

    1980-02-01

    Neutron total cross sections of /sup 6/Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx.< 10 keV. Neutron differential elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at approx.> 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;..cap alpha..)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file.

  17. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20 to 250 MeV

    SciTech Connect

    Mclean, Thomas D; Justus, Alan L; Gadd, S Milan; Olsher, Richard H; Devine, Robert T

    2009-01-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations <20 MeV on the kerma approximation, which assumes that charged particle secondaries are locally deposited, or at least that charged particle equilibrium exists within the tally cell volume. However, with increasing neutron energy the kerma approximation may no longer be valid for some energetic secondaries such as protons. The Los Alamos Monte Carlo radiation transport code MCNPX was used for all absorbed dose calculations. Transport models and collision-based energy deposition tallies were used for neutron energies >20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks <20 MeV, kerma factors were used to obtain absorbed dose. Results are presented for a discrete set of angles of incidence on an ICRU tissue slab phantom.

  18. Measurements of galactic plane gamma ray emission in the energy range from 10 - 80 MeV

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.; Kniffen, D. A.

    1982-01-01

    A spark chamber gamma ray telescope was developed and flown to observe diffuse gamma ray emission from the central region of the galaxy. The extension of observations down to 10 MeV provides important new data indicating that the galactic diffuse gamma ray spectrum continues as a power law down to about 10 MeV, an observation in good agreement with recent theoretical predictions. Data from other experiments in the range from 100 keV to 10 MeV show a significant departure from the extension of the power-law fit to the medium energy observations reported here, possibly indicating that a different mechanism may be responsible for the emissions below and above a few MeV. The intensity of the spectrum above 10 MeV implies a galactic electron spectrum which is also very intense down to about 10 MeV. Electrons in this energy range cannot be observed in the solar cavity because of solar modulation effects. The galactic gamma ray data are compared with recent theoretical predictions.

  19. Measurements of galactic plane gamma-ray emission in the energy range 10-80 MeV

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.; Kniffen, D. A.

    1983-01-01

    A spark chamber gamma ray telescope was developed and flown to observe diffuse gamma ray emission from the central region of the galaxy. The extension of observations down to 10 MeV provides important new data indicating that the galactic diffuse gamma ray spectrum continues as a power law down to about 10 MeV, an observation in good agreement with recent theoretical predictions. Data from other experiments in the range from 100 keV to 10 MeV show a significant departure from the extension of the power-law fit to the medium energy observations reported here, possibly indicating that a different mechanism may be responsible for the emissions below and above a few MeV. The intensity of the spectrum above 10 MeV implies a galactic electron spectrum which is also very intense down to about 10 MeV. Electrons in this energy range cannot be observed in the solar cavity because of solar modulation effects. The galactic gamma ray data are compared with recent theoretical predictions. Previously announced in STAR as N83-17444

  20. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20-250 MeV.

    PubMed

    Olsher, R H; McLean, T D; Justus, A L; Devine, R T; Gadd, M S

    2010-03-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations <20 MeV on the kerma approximation, which assumes that charged particle secondaries are locally deposited, or at least that charged particle equilibrium exists within the tally cell volume. However, with increasing neutron energy the kerma approximation may no longer be valid for some energetic secondaries such as protons. The Los Alamos Monte Carlo radiation transport code MCNPX was used for all absorbed dose calculations. Transport models and collision-based energy deposition tallies were used for neutron energies >20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks <20 MeV, kerma factors were used to obtain absorbed dose. Results are presented for a discrete set of angles of incidence on an ICRU tissue slab phantom. PMID:19887515

  1. Determining the Effects of EMIC Waves on Precipitating MeV Electrons during Strom Main Phases

    NASA Astrophysics Data System (ADS)

    Chen, Y.

    2015-12-01

    Theoretic studies have suggested that electromagnetic ion cyclotron (EMIC) waves can cause significant precipitation of ~MeV electrons, supposedly accounting for the fast dropouts of outer-belt electrons during storm main phases. Usually the resonance between left-hand polarized EMIC with electrons with moderate energy is unlikely due to their opposite polarizations, while resonance with highly relativistic electrons do occur and cause electrons to precipitate into the atmosphere through pitch-angle scattering. Several previous studies on observations find a close relation between the two phenomena, e.g., Cliverd et al. [2007], Sandanger et al. [2007], and Miyoshi et al. [2008], while others find otherwise, e.g., Meredith et al. [2011]; recently, more observational evidence supporting the connection has been reported (e.g., Li et al. [2014] and Blum et al. [2015]). However, whether and under what favoring conditions EMIC waves cause rapid dropouts of relativistic electrons during storm main phases remain unresolved questions. Here, using latest wave and electron data from multiple missions including Van Allen Probes, BARREL, and NOAA POES, we systemically examine the relation between EMIC waves and MeV electron precipitation. We first construct two independent event lists for intensified EMIC waves and enhancements of MeV electron precipitation, respectively. Then we cross check the two lists to identify if any significant correlation exists in between, and further characterize the wave effectiveness in terms of L-shell, MLT, resonance energy, as well as the background plasma conditions. Results from this study will advance our knowledge about the loss mechanism of outer-belt electrons, thus laying down another stepping stone towards high-fidelity physics-based models for radiation belts.

  2. Large scale silver nanowires network fabricated by MeV hydrogen (H+) ion beam irradiation

    NASA Astrophysics Data System (ADS)

    Honey, S.; Naseem, S.; Ishaq, A.; Maaza, M.; Bhatti, M. T.; Wan, D.

    2016-04-01

    A random two-dimensional large scale nano-network of silver nanowires (Ag-NWs) is fabricated by MeV hydrogen (H+) ion beam irradiation. Ag-NWs are irradiated under H+ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H+ ion beam-induced welding of Ag-NWs at intersecting positions. H+ ion beam induced welding is confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Moreover, the structure of Ag NWs remains stable under H+ ion beam, and networks are optically transparent. Morphology also remains stable under H+ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H+ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps: ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices. Project supported by the National Research Foundation of South Africa (NRF), the French Centre National pour la Recherche Scientifique, iThemba-LABS, the UNESCO-UNISA Africa Chair in Nanosciences & Nanotechnology, the Third World Academy of Science (TWAS), Organization of Women in Science for the Developing World (OWSDW), the Abdus Salam ICTP via the Nanosciences African Network (NANOAFNET), and the Higher Education Commission (HEC) of Pakistan.

  3. The Spectrum of Isotropic Diffuse Gamma-Ray Emission Between 100 Mev and 820 Gev

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Brandt, T. J.; Hays, E.; Perkins, J. S.

    2014-01-01

    The gamma-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse gamma-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission, and a longer data accumulation of 50 months, allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature, and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of 2.32 plus or minus 0.02 and a break energy of (279 plus or minus 52) GeV using our baseline diffuse Galactic emission model. The total intensity attributed to the IGRB is (7.2 plus or minus 0.6) x 10(exp -6) cm(exp -2) s(exp -1) sr(exp -1) above 100 MeV, with an additional +15%/-30% systematic uncertainty due to the Galactic diffuse foregrounds.

  4. Neutron-neutron quasifree scattering in nd breakup at 10 MeV

    NASA Astrophysics Data System (ADS)

    Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.

    2016-03-01

    The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.

  5. Extreme relativistic electron fluxes at geosynchronous orbit: Analysis of GOES E > 2 MeV electrons

    NASA Astrophysics Data System (ADS)

    Meredith, Nigel P.; Horne, Richard B.; Isles, John D.; Rodriguez, Juan V.

    2015-03-01

    Relativistic electrons (E > 1 MeV) cause internal charging on satellites and are an important space weather hazard. A key requirement in space weather research concerns extreme events and knowledge of the largest flux expected to be encountered over the lifetime of a satellite mission. This is interesting both from scientific and practical points of view since satellite operators, engineers, and the insurance industry need this information to better evaluate the effects of extreme events on their spacecraft. Here we conduct an extreme value analysis of daily averaged E > 2 MeV electron fluxes from the Geostationary Operational Environmental Satellites (GOES) during the 19.5 year period from 1 January 1995 to 30 June 2014. We find that the daily averaged flux measured at GOES West is typically a factor of about 2.5 higher than that measured at GOES East, and we conduct independent analyses for these two locations. The 1 in 10, 1 in 50, and 1 in 100 year daily averaged E > 2 MeV electron fluxes at GOES West are 1.84 ×105, 5.00 ×105, and 7.68 ×105 cm-2 s-1 sr-1, respectively. The corresponding fluxes at GOES East are 6.53 ×104, 1.98 ×105, and 3.25 ×105 cm-2 s-1 sr-1, respectively. The largest fluxes seen during the 19.5 year period on 29 July 2004 were particularly extreme and were seen by satellites at GOES West and GOES East. The extreme value analysis suggests that this event was a 1 in 50 year event.

  6. Response of a diamond detector sandwich to 14 MeV neutrons

    NASA Astrophysics Data System (ADS)

    Osipenko, M.; Ripani, M.; Ricco, G.; Caiffi, B.; Pompili, F.; Pillon, M.; Verona-Rinati, G.; Cardarelli, R.

    2016-05-01

    In this paper we present the measurement of the response of 50 μm thin diamond detectors to 14 MeV neutrons. Such neutrons are produced in fusion reactors and are of particular interest for ITER neutron diagnostics. Among semiconductor detectors diamond has properties most appropriate for harsh radiation and temperature conditions of a fusion reactor. However, 300-500 μm thick diamond detectors suffer significant radiation damage already at neutron fluences of the order of 1014 n/cm2. It is expected that a 50 μm thick diamond will withstand a fluence of >1016 n /cm2. We tested two 50 μm thick single crystal CVD diamonds, stacked to form a "sandwich" detector for coincidence measurements. The coincidence between two diamonds allows to suppress background and increase detection efficiency. The detector measured the conversion of 14 MeV neutrons, impinging on one diamond, into α particles which were detected in the second diamond in coincidence with nuclear recoil. For 12C(n , α)9Be reaction the total energy deposited in the detector gives access to the initial neutron energy value. The measured 14 MeV neutron detection sensitivity through this reaction by a detector of an effective area 3×3 mm2 was 5 ×10-7 counts cm2/n. This value is in good agreement with Geant4 simulations. The energy resolution of the detector was found to be 870 keV FWHM, but according to Geant4 simulations only about 160 keV FWHM were intrinsic.

  7. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies

    DOE PAGES

    Abbott, D.; Adderley, P.; Adeyemi, A.; Aguilera, P.; Ali, M.; Areti, H.; Baylac, M.; Benesch, J.; Bosson, G.; Cade, B.; et al

    2016-05-27

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19~MeV/c, limited only by the electron beam polarization. We report that this technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  8. Carcinoma of the cervix: surgical staging and radiotherapy with 32 MeV Betatron

    SciTech Connect

    Shah, K.; Olson, M.H.; Dillard, E.A.

    1982-09-01

    Fifty-six patients with squamous cell carcinoma of the cervix were staged by exploratory laparotomy. Twenty-eight of them received radiotherapy with 32 MeV Betatron and intracavitary radium. Twenty-one patients with Stage IB or IIA had a radical hysterectomy, five had post-operative pelvic irradiation, and two had primary exenteration. An overall 23.2% of patients had metastases in the paraaortic fields. Four patients with paraaortic node disease received extended field irradiation: 4500 rad in 5 weeks to paraaortic nodes. Two of them are alive and disease-free at 5.5 to 6.5 years.

  9. The Gent University 15 MeV high-current linear electron accelerator facility

    NASA Astrophysics Data System (ADS)

    Mondelaers, W.; Van Laere, K.; Goedefroot, A.; Van den Bossche, K.

    1996-01-01

    The Gent University 15 MeV 20kW linear electron accelerator facility was initially designed for fundamental nuclear physics research. During the last years a large effort has been devoted to the expansion of the range of machine applications in view of a new extensive experimental programme in the fields of atomic and solid-state physics, biomaterials research, polymer chemistry, space research, food technology, high-dose dosimetry and radiation therapy. The accelerator facility in its present configuration, the peripheral equipment and the experimental programme are described with emphasis on the original features.

  10. Applied radiation research around a 15 MeV high-average-power linac

    NASA Astrophysics Data System (ADS)

    Lahorte, P.; Mondelaers, W.; De Frenne, D.; Callens, F.; Vanhaelewyn, G.; Schacht, E.; Van Calenberg, S.; Van Cleemput, O.; Huyghebaert, A.

    1999-08-01

    The Department of Subatomic and Radiation Physics of the University Gent is equipped with a 15 MeV 20 kW linear electron accelerator (linac) facility. In its present configuration the accelerator is used as a multipurpose apparatus for research in the fields of polymer chemistry, biomedical materials, medicine, food technology, dosimetry, solid state physics, agriculture and nuclear and radiation physics. We present an overview of both the various research projects around our linac facility involving radiation chemistry and physics and the specialised technologies facilitating this research.

  11. Determination of alumina in sintered aluminium powder by activation with 14-MeV neutrons.

    PubMed

    Español, C E; Marafuschi, A M

    1970-07-01

    Fast neutrons of 14 MeV produced in the IMICAM CISE 150-kV generator by the (d, t) reaction in a tritium-titanium target, were used in the indirect determination of Al(2)O(3). The samples were irradiated for 30 sec and the total (16)N activity was determined, by counting for ten 2-sec periods and graphically integrating. The standards were a known sintered aluminium powder and nylon pieces of identical shape. The method is competitive with the chemical one, because of its quickness, sensitivity and precision. PMID:18960787

  12. Gamma-ray-spectroscopy following high-flux 14-MeV neutron activation

    SciTech Connect

    Williams, R.E.

    1981-10-12

    The Rotating Target Neutron Source (RTNS-I), a high-intensity source of 14-MeV neutrons at the Lawrence Livermore National Laboratory (LLNL), has been used for applications in activation analysis, inertial-confinement-fusion diagnostic development, and fission decay-heat studies. The fast-neutron flux from the RTNS-I is at least 50 times the maximum fluxes available from typical neutron generators, making these applications possible. Facilities and procedures necessary for gamma-ray spectroscopy of samples irradiated at the RTNS-I were developed.

  13. α-clustering effects in dissipative 12C + 12C reactions at 95 MeV

    NASA Astrophysics Data System (ADS)

    Baiocco, G.; Morelli, L.; Gulminelli, F.; D'Agostino, M.; Bruno, M.; Abbondanno, U.; Barlini, S.; Bini, M.; Carboni, S.; Casini, G.; Cinausero, M.; Degerlier, M.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Olmi, A.; Pasquali, G.; Piantelli, S.; Raduta, Ad. R.

    2013-05-01

    Dissipative 12C+12C reactions at 95 MeV are fully detected in charge with the GARFIELD and RCo apparatuses at Laboratori Nazionali di Legnaro. A comparison to a dedicated Hauser-Feshbach calculation allows us to select events which correspond, to a large extent, to the statistical evaporation of highly excited 24Mg, as well as to extract information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain. Residual deviations from statistical behavior are observed in α yields and attributed to the persistence of cluster correlations well above the 24Mg threshold for six-α decay.

  14. Regrowth-related defect formation and evolution in 1 MeV amorphized (001) Ge

    SciTech Connect

    Hickey, D. P.; Bryan, Z. L.; Jones, K. S.; Elliman, R. G.; Haller, E. E.

    2007-03-26

    Ge implanted with 1 MeV Si{sup +} at a dose of 1x10{sup 15} cm{sup -2} creates a buried amorphous layer that, upon regrowth, exhibits several forms of defects-end-of-range (EOR), regrowth-related, and clamshell defects. Unlike Si, no planar (311) defects are observed. The minimal EOR defects are small dotlike defects and are very unstable, dissolving between 450 and 550 deg. C. This is in contrast to Si, where the EOR defects are very stable. The amorphous layer results in both regrowth-related defects and clamshell defects, which were more stable than the EOR damage.

  15. Alpha Production Cross Sections for Some Target Fusion Structural Materials up to 35 MeV

    NASA Astrophysics Data System (ADS)

    Yiğit, M.; Tel, E.

    2013-08-01

    In the next century, because of the worldwide energy shortage, human life will badly be affected. Nuclear fusion energy is the remarkable solution to the rising energy challenges because it has the great potential for sustainability, economic and reliability. There have been many research and development studies to get energy from fusion. Moreover, the neutron induced reaction cross section data around 14-15 MeV are need to the design and development of nuclear fusion reactors. Thus, the working out the systematics of ( n, α) reaction cross sections is very important and necessary for the definition of the excitation curves at around 14-15 MeV energy. In this study, neutron induced reaction cross sections for structural fusion materials such as Sc ( Scandium), Co ( Cobalt), Ni ( Nickel), Cu ( Copper), Y ( Yttrium), Mo ( Molybdenum), Zr ( Zirconium) and Nb ( Niobium) have been investigated for the ( n, α) reactions. The new calculations on the excitation functions of 45 Sc( n, a) 42 K, 59 Co ( n, a) 56 Mn, 62 Ni( n, a) 59 Fe, 63 Cu( n, a) 60 Co, 65 Cu( n, a) 62 Co, 89 Y( n, a) 86 Rb, 92 Mo( n, a) 89 Zr, 98 Mo( n, a) 95 Zr, 92 Zr( n, a) 89 Sr, 94 Zr( n, a) 91 Sr and 93 Nb( n, a) 90 Y reactions have been carried out up to 35 MeV incident neutron energies. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model, hybrid model and the cascade exciton model. The equilibrium effects of the excitation functions for the investigated reactions are calculated according to the Weisskopf-Ewing model. Additionaly, in the present work, the ( n, α) reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The calculated results have been discussed and compared with the available experimental data taken from EXFOR database.

  16. 6 MeV heavy ion beam probe on the Large Helical Device

    SciTech Connect

    Ido, T.; Shimizu, A.; Nishiura, M.; Nishizawa, A.; Katoh, S.; Tsukada, K.; Yokota, M.; Ogawa, H.; Inoue, T.; Hamada, Y.; Crowley, T. P.

    2006-10-15

    A heavy ion beam probe (HIBP) has been installed on the Large Helical Device (LHD). A MeV-range beam is required for the LHD-HIBP. The probing beam is accelerated up to 6 MeV by use of a tandem accelerator. A new energy analyzer with tandem electrodes has also been developed to analyze such a high energy beam. As a result, a secondary beam can be detected and its energy successfully analyzed. It is verified, in principle, that the potential profile can be measured using the HIBP.

  17. Nuclear excitation functions from 40 to 200 MeV proton irradiation of terbium

    NASA Astrophysics Data System (ADS)

    Engle, Jonathan W.; Mashnik, Stepan G.; Parker, Lauren A.; Jackman, Kevin R.; Bitteker, Leo J.; Ullmann, John L.; Gulley, Mark S.; Pillai, Chandra; John, Kevin D.; Birnbaum, Eva R.; Nortier, Francois M.

    2016-01-01

    Nuclear formation cross sections are reported for 26 radionuclides, measured with 40-200 MeV proton irradiations of terbium foils. These data provide the basis for the production of medically relevant radionuclides (e.g., 152Tb, 155Tb, 155Eu, and 156Eu) and 153Gd, a potential source used in ongoing efforts to characterize stellar nucleosynthesis routes. Computational predictions from the ALICE2011, CEM03.03, Bertini, and INCL + ABLA codes are compared with newly measured data to contribute to the ongoing process of code development, and yields are calculated for selected radionuclides using measured data.

  18. Parity Nonconservation in Proton-water Scattering at 800 MeV

    DOE R&D Accomplishments Database

    Nagle, D. E.; Bowman, J. D.; Carlini, R.; Mischke, R. E.; Frauenfelder, H.; Harper, R. W.; Yuan, V.; McDonald, A. B.; Talaga, R.

    1982-01-01

    A search has been made for parity nonconservation in the scattering of 800 MeV polarized protons from an unpolarized water target. The result is for the longitudinal asymmetry, A{sub L} = +(6.6 +- 3.2) x 10{sup -7}. Control runs with Pb, using a thickness which gave equivalent beam broadening from Coulomb multiple scattering, but a factor of ten less nuclear interactions than the water target, gave A{sub L} = -(0.5 +- 6.0) x 10{sup -7}.

  19. Design and modelling of a 5 MeV radio frequency electron gun

    SciTech Connect

    Batchelor, K.; Sheehan, J.; Woodle, M.

    1988-08-22

    The Accelerator Test Facility (ATF) at Brookhaven National Laboratory is a linac-laser complex for research into laser acceleration and for the generation of coherent radiation from electron beams. In order to achieve the design 50 MeV output emittance (..gamma..sigma/sub x/sigma/sub x/') of less than 3 /times/ 10/sup /minus/5/ m rad a high brightness electron gun is required. This paper describes computations and measurements made on a full scale brass model of a 1-1/2 cell, ..pi..-mode, resonant, disc loaded, radiofrequency gun structure which has been designed for this purpose. 7 refs., 9 figs., 6 tabs.

  20. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies.

    PubMed

    Abbott, D; Adderley, P; Adeyemi, A; Aguilera, P; Ali, M; Areti, H; Baylac, M; Benesch, J; Bosson, G; Cade, B; Camsonne, A; Cardman, L S; Clark, J; Cole, P; Covert, S; Cuevas, C; Dadoun, O; Dale, D; Dong, H; Dumas, J; Fanchini, E; Forest, T; Forman, E; Freyberger, A; Froidefond, E; Golge, S; Grames, J; Guèye, P; Hansknecht, J; Harrell, P; Hoskins, J; Hyde, C; Josey, B; Kazimi, R; Kim, Y; Machie, D; Mahoney, K; Mammei, R; Marton, M; McCarter, J; McCaughan, M; McHugh, M; McNulty, D; Mesick, K E; Michaelides, T; Michaels, R; Moffit, B; Moser, D; Muñoz Camacho, C; Muraz, J-F; Opper, A; Poelker, M; Réal, J-S; Richardson, L; Setiniyaz, S; Stutzman, M; Suleiman, R; Tennant, C; Tsai, C; Turner, D; Ungaro, M; Variola, A; Voutier, E; Wang, Y; Zhang, Y

    2016-05-27

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19  MeV/c, limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community. PMID:27284661

  1. A diamond 14 MeV neutron energy spectrometer with high energy resolution.

    PubMed

    Shimaoka, Takehiro; Kaneko, Junichi H; Ochiai, Kentaro; Tsubota, Masakatsu; Shimmyo, Hiroaki; Chayahara, Akiyoshi; Umezawa, Hitoshi; Watanabe, Hideyuki; Shikata, Shin-ichi; Isobe, Mitsutaka; Osakabe, Masaki

    2016-02-01

    A self-standing single-crystal chemical vapor deposited diamond was obtained using lift-off method. It was fabricated into a radiation detector and response function measurements for 14 MeV neutrons were taken at the fusion neutronics source. 1.5% of high energy resolution was obtained by using the (12)C(n, α)(9)Be reaction at an angle of 100° with the deuteron beam line. The intrinsic energy resolution, excluding energy spreading caused by neutron scattering, slowing in the target and circuit noises was 0.79%, which was also the best resolution of the diamond detector ever reported.

  2. Cross Sections for n+89Y for En< 20 MeV

    SciTech Connect

    Garrett, P E; Ormand, W E; Younes, W; Becker, J A; Bernstein, L A; Nelson, R O; Devlin, M; Fotiades, N

    2003-04-18

    Nuclear data collected in an experiment performed at LANSCE/WNR with the GEANIE spectrometer to measure the cross sections for n + {sup 89}Y for E{sub n} < 20 MeV are reported. The estimated (n,2n) cross sections to the ground and isomeric states of {sup 88}Y differ significantly from those listed in the RADCHEM data base. Folded with a fast neutron spectrum, these results lead to integral differences of +15%, +2%, and -70% vs. the RADCHEM evaluation.

  3. Phenomenological optical potential analysis of proton-carbon elastic scattering at 200 MeV

    NASA Technical Reports Server (NTRS)

    Bidasaria, H. B.; Townsend, L. W.

    1982-01-01

    Differential cross sections for 200 MeV protons elastically scattered from C-12 were analyzed utilizing a local, complex, spin-dependent optical potential with a harmonic well radial dependence. Analyses were performed using the WKB and eikonal approximations. For the latter, first-order corrections to he phase shifts were incorporated to account for the spin-orbit contribution. Large disagreement between theory and experiment was observed when the usual Thomas form for the spin-orbit potential was utilized. Substantial improvement was obtained by allowing the parameters in the central and spin-orbit potential terms to vary independently.

  4. Comparison of beam simulations with measurements for a 1.25-MeV, CW RFQ

    SciTech Connect

    Smith, H.V. Jr.; Bolme, G.O.; Sherman, J.D.; Stevens, R.R. Jr.; Young, L.M.; Zaugg, T.J.

    1998-12-31

    The Low-Energy Demonstration Accelerator (LEDA) injector is tested using the Chalk River Injector Test Stand (CRITS) radio-frequency quadrupole (RFQ) as a diagnostic instrument. Fifty-keV, dc proton beams are injected into the 1.25-MeV, CW RFQ and transported to a beamstop. Computer-simulation-code predictions of the expected beam performance are compared with the measured beam currents and beam profiles. Good agreement is obtained between the measurements and the simulations at the 75-mA design RFQ output current.

  5. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies.

    PubMed

    Abbott, D; Adderley, P; Adeyemi, A; Aguilera, P; Ali, M; Areti, H; Baylac, M; Benesch, J; Bosson, G; Cade, B; Camsonne, A; Cardman, L S; Clark, J; Cole, P; Covert, S; Cuevas, C; Dadoun, O; Dale, D; Dong, H; Dumas, J; Fanchini, E; Forest, T; Forman, E; Freyberger, A; Froidefond, E; Golge, S; Grames, J; Guèye, P; Hansknecht, J; Harrell, P; Hoskins, J; Hyde, C; Josey, B; Kazimi, R; Kim, Y; Machie, D; Mahoney, K; Mammei, R; Marton, M; McCarter, J; McCaughan, M; McHugh, M; McNulty, D; Mesick, K E; Michaelides, T; Michaels, R; Moffit, B; Moser, D; Muñoz Camacho, C; Muraz, J-F; Opper, A; Poelker, M; Réal, J-S; Richardson, L; Setiniyaz, S; Stutzman, M; Suleiman, R; Tennant, C; Tsai, C; Turner, D; Ungaro, M; Variola, A; Voutier, E; Wang, Y; Zhang, Y

    2016-05-27

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19  MeV/c, limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  6. MeV negative ion source from ultra-intense laser-matter interaction

    SciTech Connect

    Ter-Avetisyan, S.; Ramakrishna, B.; Doria, D.; Prasad, R.; Borghesi, M.; Andreev, A. A.; Steinke, S.; Schnuerer, M.; Nickles, P. V.; Tikhonchuk, V.

    2012-02-15

    Experimental demonstration of negative ion acceleration to MeV energies from sub-micron size droplets of water spray irradiated by ultra-intense laser pulses is presented. Thanks to the specific target configuration and laser parameters, more than 10{sup 9} negative ions per steradian solid angle in 5% energy bandwidth are accelerated in a stable and reliable manner. To our knowledge, by virtue of the ultra-short duration of the emission, this is by far the brightest negative ion source reported. The data also indicate the existence of beams of neutrals with at least similar numbers and energies.

  7. NEUTRON CROSS SECTION COVARIANCES FROM THERMAL ENERGY TO 20 MeV.

    SciTech Connect

    ROCHMAN,D.; HERMAN, M.; OBLOZINSKY, P.; MUGHABGHAB, S.F.; PIGNI, M.; KAWANO, T.

    2007-04-27

    We describe new method for energy-energy covariance calculation from the thermal energy up to 20 MeV. It is based on three powerful basic components: (i) Atlas of Neutron Resonances in the resonance region; (ii) the nuclear reaction model code EMPIRE in the unresolved resonance and fast neutron regions, and (iii) the Bayesian code KALMAN for correlations and error propagation. Examples for cross section uncertainties and correlations on {sup 90}Zr and {sup 193}Ir illustrate this approach in the resonance and fast neutron regions.

  8. Partial-wave analysis of all nucleon-nucleon scattering data below 350 MeV

    SciTech Connect

    Stoks, V.G.J.; Klomp, R.A.M.; Rentmeester, M.C.M.; de Swart, J.J. )

    1993-08-01

    We present a multienergy partial-wave analysis of all [ital NN] scattering data below [ital T][sub lab]=350 MeV, published in a regular physics journal between 1955 and 1992. After careful examination, our final database consists of 1787 [ital pp] and 2514 [ital np] scattering data. Our fit to these data results in [chi][sup 2]/[ital N][sub df]=1.08, with [ital N][sub df]=3945 the total number of degrees of freedom. All phase shifts and mixing parameters can be determined accurately.

  9. MeV Mono-Energetic Gamma Ray Compton Scattering Source R&D

    NASA Astrophysics Data System (ADS)

    Hartemann, Fred; Albert, Felicie; Anderson, Scott; Chu, Sam; Cross, Rick; Ebbers, Chris; Gibson, David; Messerly, Mike; Semenov, Vlad; Shverdin, Miro; Siders, Craig; McNabb, Dennis; Barty, Chris; Vlieks, Arnold; Tantawi, Sami

    2009-11-01

    A precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development at LLNL. High-brightness, relativistic electron bunches produced by the linac interact with a Joule-class, 10 ps laser pulse to generate tunable γ-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. The source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented.

  10. Neutron-proton spin-correlation parameter A sub z z at 68 MeV

    SciTech Connect

    Hammans, M.; Brogli-Gysin, C.; Burzynski, S.; Campbell, J.; Haffter, P.; Henneck, R.; Lorenzon, W.; Pickar, M.A.; Sick, I. ); Konter, J.A.; Mango, S.; van den Brandt, B. )

    1991-05-06

    We report a first measurement of the spin-correlation parameter {ital A}{sub {ital z}{ital z}} in neutron-proton scattering at 67.5 MeV. The results, obtained in the angular range 105{degree}{le}{theta}{sub c.m.}{le}170{degree} with typical accuracies of 0.008, are highly sensitive to the {sup 3}{ital S}{sub 1}-{sup 3}{ital D}{sub 1} mixing parameter {epsilon}{sub 1}. A phase-shift analysis based on the current world data yields a value of {epsilon}{sub 1} significantly higher than predicted by modern potential models.

  11. Scale size of magnetic turbulence in tokamaks probed with 30-MeV electrons

    PubMed

    Entrop; Lopes Cardozo NJ; Jaspers; Finken

    2000-04-17

    Measurements of synchrotron radiation emitted by 30-MeV runaway electrons in the TEXTOR-94 tokamak show that the runaway population decays after switching on neutral beam injection (NBI). The decay starts only with a significant delay, which decreases with increasing NBI heating power. This delay provides direct evidence of the energy dependence of runaway confinement, which is expected if magnetic modes govern the loss of runaways. Application of the theory by Mynick and Strachan [Phys. Fluids 24, 695 (1981)] yields estimates for the "mode width" (delta) of magnetic perturbations: delta<0.5 cm in Ohmic discharges, increasing to delta = 4.4 cm for 0. 6 MW NBI.

  12. Semi-annual report of the Department of Energy, Office of Environmental Management, Quality Assessment Program. QAP 49 summary of evaluations of 3217 reported analyses

    SciTech Connect

    Greenlaw, P.D.

    1998-12-01

    This Quality Assessment Program (QAP) is designed to test the quality of the environmental measurements being reported to the Department of Energy by its contractors. Since 1976, real or synthetic environmental samples that have been prepared and thoroughly analyzed at the Environmental measurements Laboratory (EML) have been distributed at first quarterly and then semi-annually to these contractors. Their results, which are returned to EML within 90 days, are compiled with EML`s results and are reported back to the participating contractors 30 days later. A summary of the reported results is available to the participants 4 days after the reporting deadline via the Internet at www.eml.doe.gov. This report presents the results from the analysis of the 49th set of environmental quality assessment samples (QAP XLIX) that were received on or before December 1, 1998.

  13. Detectable MeV neutrinos from black hole neutrino-dominated accretion flows

    NASA Astrophysics Data System (ADS)

    Liu, Tong; Zhang, Bing; Li, Ye; Ma, Ren-Yi; Xue, Li

    2016-06-01

    Neutrino-dominated accretion flows (NDAFs) around rotating stellar-mass black holes (BHs) have been theorized as the central engine of relativistic jets launched in massive star core collapse events or compact star mergers. In this work, we calculate the electron neutrino/antineutrino spectra of NDAFs by fully taking into account the general relativistic effects, and investigate the effects of viewing angle, BH spin, and mass accretion rate on the results. We show that even though a typical NDAF has a neutrino luminosity lower than that of a typical supernova (SN), it can reach 1050- 1051 erg s-1 peaking at ˜10 MeV , making NDAFs potentially detectable with the upcoming sensitive MeV neutrino detectors if they are close enough to Earth. Based on the observed gamma-ray burst (GRB) event rate in the local universe and requiring that at least three neutrinos are detected to claim a detection, we estimate a detection rate up to ˜(0.10 - 0.25 ) per century for GRB-related NDAFs by the Hyper-Kamiokande (Hyper-K) detector if one neglects neutrino oscillation. If one assumes that all type Ib/c SNe have an engine-driven NDAF, the Hyper-K detection rate would be ˜(1 - 3 ) per century. By considering neutrino oscillations, the detection rate may decrease by a factor of 2-3. Detecting one such event would establish the observational evidence of NDAFs in the Universe.

  14. The Angular Distribution of Neutrons Scattered from Deuterium below 2 MeV

    NASA Astrophysics Data System (ADS)

    Nankov, N.; Plompen, A. J. M.; Kopecky, S.; Kozier, K. S.; Roubtsov, D.; Rao, R.; Beyer, R.; Grosse, E.; Hannaske, R.; Junghans, A. R.; Massarczyk, R.; Schwengner, R.; Yakorev, D.; Wagner, A.; Stanoiu, M.; Canton, L.; Nolte, R.; Röttger, S.; Beyer, J.; Svenne, J.

    2014-05-01

    Neutron elastic scattering measurements were carried out at the nELBE neutron time-of-flight facility at a 6 m flight path. Energies below 2 MeV were studied using a setup consisting of eight 6Li-glass detectors placed at nominal angles of 15∘ and 165∘ with respect to the incident neutron beam. A deuterated polyethylene sample with 99.999% enrichment in deuterium was used. These angles were chosen since an earlier study showed that the ratio of the differential cross section at these angles is the most sensitive to differences in evaluated files and model calculations. Accurate 165∘/15∘ angle ratios were obtained. Above 1 MeV these are somewhat larger than given by ENDF/B-VII. Simultaneously the early day experiments using a proportional counter to infer angular distributions from deuterium recoil pulse height distributions are being studied through a new experiment with such a device at the Physikalisch-Technische Bundesanstalt (PTB). At 500 keV this experiment favors ENDF/B-VII over JENDL-4.0, while at lower energies agreement with the data is similar.

  15. A scintillating-fiber 14-MeV neutron detector on TFTR during DT operation

    SciTech Connect

    Wurden, G.A.; Chrien, R.E.; Barnes, C.W.; Sailor, W.C.; Roquemore, A.L.; Lavelle, M.J.; O`Gara, P.M.; Jordan, R.J.

    1994-07-01

    A compact 14-MeV neutron detector using an array of scintillating fibers has been tested on the TFTR tokamak under conditions of a high gamma background. This detector uses a fiber-matrix geometry, a magnetic field-insensitive phototube with an active HV base and pulse-height discrimination to reject low-level pulses from 2.5 MeV neutron and intense gammas. Laboratory calibrations have been performed at EG&G Las Vegas using a pulsed DT neutron generator and a 30 kCi {sup 60}Co source as background, at PPPL using DT neutron sources, and at LANL using an energetic deuterium beam and target at a tandem Van de Graaff accelerator. During the first high power DT shots on TFTR in December 1993, the detector was 15.5 meters from the torus in a large collimator. For a rate of 1 {times} 10{sup 18} n/sec from the tokamak, it operated in an equivalent background of 1 {times} 10{sup 10} gammas/cm{sup 2}/sec ({approximately}4 mA current drain) at a DT count rate of 200 kHz.

  16. Interlock system for machine protection of the KOMAC 100-MeV proton linac

    NASA Astrophysics Data System (ADS)

    Song, Young-Gi

    2015-02-01

    The 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC) has been developed. The beam service started this year after performing the beam commissioning. If the very sensitive and essential equipment is to be protected during machine operation, a machine interlock system is required, and the interlock system has been implemented. The purpose of the interlock system is to shut off the beam when the radio-frequency (RF) and ion source are unstable or a beam loss occurs. The interlock signal of the KOMAC linac includes a variety of sources, such as the beam loss, RF and high-voltage converter modulator faults, and fast closing valves of the vacuum window at the beam lines and so on. This system consists of a hardware-based interlock system using analog circuits and a software-based interlock system using an industrial programmable logic controller (PLC). The hardware-based interlock system has been fabricated, and the requirement has been satisfied with the results being within 10 µs. The software logic interlock system using the PLC has been connected to the framework of with the experimental physics and industrial control system (EPICS) to integrate a variety of interlock signals and to control the machine components when an interlock occurs. This paper will describe the design and the construction of the machine interlock system for the KOMAC 100-MeV linac.

  17. Development of a 20 MeV Dielectric-Loaded Accelerator Test Facility

    SciTech Connect

    Gold, Steven H.; Fliflet, Arne W.; Kinkead, Allen K.; Gai Wei; Power, John G.; Konecny, Richard; Jing Chunguang; Tantawi, Sami G.; Nantista, Christopher D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, Ralph W.; Bruce, Robert L.; Lewis, David III

    2004-12-07

    This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the StanFord Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron injector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx}8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

  18. Development of a 20-MeV Dielectric-Loaded Accelerator Test Facility

    SciTech Connect

    Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.G.; Tantawi, S.G.; Nantista, C.D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, R.W.; Bruce, R.L.; Fliflet, A.W.; Lewis, D.; /Naval Research Lab, Wash., D.C. /LET Corp., Washington /Argonne /SLAC /Tsinghua U., Beijing

    2005-06-22

    This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron inector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx} 8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRl, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

  19. Production of α-particle emitting 211At using 45 MeV α-beam

    NASA Astrophysics Data System (ADS)

    Kim, Gyehong; Chun, Kwonsoo; Park, Sung Ho; Kim, Byungil

    2014-06-01

    Among the α-particle emitting radionuclides, 211At is considered to be a promising radionuclide for targeted cancer therapy due to its decay properties. The range of alpha particles produced by the decay of 211At are less than 70 µm in water with a linear energy transfer between 100 and 130 keV µm-1, which are about the maximum relative biological effectiveness for heavy ions. It is important to note that at the present time, only a few of cyclotrons routinely produce 211At. The direct production method is based on the nuclear reactions 209Bi(α,2n)211At. Production of the radionuclide 211At was carried out using the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). To ensure high beam current, the α-beam was extracted with an initial energy of 45 MeV, which was degraded to obtain the appropriate α-beam energy. The calculations of beam energy degradation were performed utilizing the MCNPX. Alumina-baked targets were prepared by heating the bismuth metal powder onto a circular cavity in a furnace. When using an Eα, av of 29.17 MeV, the very small contribution of 210At confirms the right choice of the irradiation energy to obtain a pure production of 211At isotope.

  20. Study of beamlet deflection and its compensations in a MeV accelerator

    SciTech Connect

    Kashiwagi, Mieko; Inoue, Takashi; Taniguchi, Masaki; Umeda, Naotaka; Dairaku, Masayuki; Takemoto, Jumpei; Tobari, Hiroyuki; Tsuchida, Kazuki; Watanabe, Kazuhiro; Yamanaka, Haruhiko; Sakamoto, Keishi; Grisham, Larry R.

    2011-09-26

    In a five stage multi-aperture and multi-grid (MAMuG) accelerator in JAEA, beam acceleration tests are in progress toward 1 MeV, 200 A/m{sup 2} H{sup -} ion beams for ITER. The 1 MV voltage holding has been successfully demonstrated for 4,000 s with the accelerator of expanded gap length that lowered local electric field concentrations. This led to increase of the beam energy up to 900 keV-level. However, it was found that beamlets were deflected more in long gaps and direct interceptions of the deflected beamlet caused breakdowns. The beamlet deflection and its compensation methods were studied utilizing a three-dimensional multi beamlet analysis. The analysis showed that the 1 MeV beam can be compensated by a combination of the aperture offset of 0.8 mm applied in the electron suppression (ESG) and the metal bar called a field shaping plate with a thickness of 1 mm attached beneath the ESG. The paper reports these compensation methods and analytical predictions, with experimental results of the MAMuG accelerator in which those compensation techniques have been applied.

  1. Beam tracking simulation in the central region of a 13 MeV PET cyclotron

    NASA Astrophysics Data System (ADS)

    Anggraita, Pramudita; Santosa, Budi; Taufik, Mulyani, Emy; Diah, Frida Iswinning

    2012-06-01

    This paper reports the trajectories simulation of proton beam in the central region of a 13 MeV PET cyclotron, operating with negative proton beam (for easier beam extraction using a stripper foil), 40 kV peak accelerating dee voltage at fourth harmonic frequency of 77.88 MHz, and average magnetic field of 1.275 T. The central region covers fields of 240mm × 240mm × 30mm size at 1mm resolution. The calculation was also done at finer 0.25mm resolution covering fields of 30mm × 30mm × 4mm size to see the effects of 0.55mm horizontal width of the ion source window and the halted trajectories of positive proton beam. The simulations show up to 7 turns of orbital trajectories, reaching about 1 MeV of beam energy. The distribution of accelerating electric fields and magnetic fields inside the cyclotron were calculated in 3 dimension using Opera3D code and Tosca modules for static magnetic and electric fields. The trajectory simulation was carried out using Scilab 5.3.3 code.

  2. Toward 10 meV electron energy-loss spectroscopy resolution for plasmonics.

    PubMed

    Bellido, Edson P; Rossouw, David; Botton, Gianluigi A

    2014-06-01

    Energy resolution is one of the most important parameters in electron energy-loss spectroscopy. This is especially true for measurement of surface plasmon resonances, where high-energy resolution is crucial for resolving individual resonance peaks, in particular close to the zero-loss peak. In this work, we improve the energy resolution of electron energy-loss spectra of surface plasmon resonances, acquired with a monochromated beam in a scanning transmission electron microscope, by the use of the Richardson-Lucy deconvolution algorithm. We test the performance of the algorithm in a simulated spectrum and then apply it to experimental energy-loss spectra of a lithographically patterned silver nanorod. By reduction of the point spread function of the spectrum, we are able to identify low-energy surface plasmon peaks in spectra, more localized features, and higher contrast in surface plasmon energy-filtered maps. Thanks to the combination of a monochromated beam and the Richardson-Lucy algorithm, we improve the effective resolution down to 30 meV, and evidence of success up to 10 meV resolution for losses below 1 eV. We also propose, implement, and test two methods to limit the number of iterations in the algorithm. The first method is based on noise measurement and analysis, while in the second we monitor the change of slope in the deconvolved spectrum.

  3. Neutron induced inelastic cross sections of 150Sm for En = 1 to 35 MeV

    SciTech Connect

    Dashdorj, D; Mitchell, G E; Kawano, T; Becker, J A; Agvaanluvsan, U; Chadwick, M B; Cooper, J R; Devlin, M; Fotiades, N; Garrett, P E; Nelson, R O; Wu, C Y; Younes, W

    2006-08-16

    Cross-section measurements were made of prompt gamma-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) 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). Partial {gamma}-ray cross sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH 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 pre-equilibrium effects is discussed.

  4. Neutron induced light-ion production from Iron and Bismuth at 175 MeV

    NASA Astrophysics Data System (ADS)

    Bevilacqua, R.; Pomp, S.; Simutkin, V.; Tippawan, U.; Andersson, P.; Blomgren, J.; Österlund, M.; Hayashi, M.; Hirayama, S.; Naito, Y.; Watanabe, Y.; Tesinsky, M.; Lecolley, F.-R.; Marie, N.; Hjalmarsson, A.; Prokofiev, A.; Kolozhvari, A.

    2010-03-01

    We have measured light-ion (p, d, t, 3He and α) production in the interaction of 175 MeV neutrons with iron and bismuth, using the MEDLEY setup. A large set of measurements at 96 MeV has been recently completed and published, and now higher energy region is under investigation. MEDLEY is a conventional spectrometer system that allows low-energy thresholds and offers measurements over a wide angular range. The system consists of eight telescopes, each of them composed of two silicon surface barrier detectors, to perform particle identification, and a CsI(Tl) scintillator to fully measure the kinetic energy of the produced light-ions. The telescopes are placed at angles from 20° to 160°, in steps of 20°. Measurements have been performed at The Svedberg Laboratory, Uppsala (Sweden), where a quasi mono-energetic neutron beam is available and well characterized. Time of flight techniques are used to select light-ion events induced by neutrons in the main peak of the source neutron spectrum. We report preliminary double differential cross sections for production of protons, deuterons and tritons in comparison with model calculations using TALYS-1.0 code.

  5. Deuterium microscopy using 17 MeV deuteron-deuteron scattering

    NASA Astrophysics Data System (ADS)

    Reichart, Patrick; Moser, Marcus; Greubel, Christoph; Peeper, Katrin; Dollinger, Günther

    2016-03-01

    Using 17 MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron-deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5 sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150 ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25 MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering (~100 mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron-proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel. A deuterium detection limit due to accidental coincidences of 3 at-ppm down to less than 1 at-ppm is demonstrated on deuterated polypropylen sheets as well as thick polycarbonate sheets after various stages of coincidence filtering that is possible with our granular detector.

  6. Diagnostics for a 1.2 kA, 1 MeV electron induction injector

    SciTech Connect

    Houck, T.L.; Anderson, D.E.; Eylon, S.; Henestroza, E.; Lidia, S.M.; Vanecek, D.L.; Westenskow, G.A.; Yu, S.S.

    1998-05-11

    We are constructing a 1.2-kA, 1-MeV, electron induction injector as part of the RTA program, a collaborative effort between LLNL and LBNL to develop relativistic klystrons for Two-Beam Accelerator applications. The RTA injector will also be used in the development of a high-gradient, low-emittance, electron source and beam diagnostics for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility. The electron source will be a 3.5``-diameter, thermionic, flat-surface, m-type cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 200 {pi}-mm-mr. Precise measurement of the beam parameters is required so that performance of the RTA injector can be confidently scaled to the 4-kA, 3-MeV, and 2-microsecond pulse parameters of the DARHT injector. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepper-pot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.

  7. The 2.5 MeV neutron flux monitor for MAST

    NASA Astrophysics Data System (ADS)

    Cecconello, M.; Sangaroon, S.; Conroy, S.; Donato, M.; Ericsson, G.; Marini-Bettolo, C.; Ronchi, R.; Stro¨m, P.; Weiszflog, M.; Wodniak, I.; Turnyanskiy, M.; Akers, R.; Cullen, A.; Fitzgerald, I.; McArdle, G.; Pacoto, C.; Thomas-Davies, N.

    2014-07-01

    A proof-of-principle collimated Neutron flux Camera (NC) monitor for the measurement of the 2.45 MeV neutron emission from the deuterium-deuterium fusion reactions has been developed, installed and put into use at the Mega Ampere Spherical Tokamak (MAST). The NC measures the spatial and time resolved volume integrated neutron emissivity in deuterium fusion plasmas in the presence of auxiliary plasma heating along two equatorial and two diagonal lines of sight whose tangency radius can be varied between plasma discharges. This paper describes the NC design principles, their technical realization and its performances illustrated with experimental observations of different plasma scenarios. Neutron count rates in the range 0.1-1.5 MHz are routinely observed allowing time resolutions as high as 1 ms with a statistical uncertainty less than 10% and an energy threshold of 0.5 MeV. Examples of the effect of plasma instabilities on the neutron emission are presented. The good results obtained will be used for the design of the neutron flux camera monitor for MAST Upgrade.

  8. Dosimetric shield evaluation with tungsten sheet in 4, 6, and 9MeV electron beams.

    PubMed

    Fujimoto, Takahiro; Monzen, Hajime; Nakata, Manabu; Okada, Takashi; Yano, Shinsuke; Takakura, Toru; Kuwahara, Junichi; Sasaki, Makoto; Higashimura, Kyoji; Hiraoka, Masahiro

    2014-11-01

    In electron radiotherapy, shielding material is required to attenuate beam and scatter. A newly introduced shielding material, tungsten functional paper (TFP), has been anticipated to become a very useful device that is lead-free, light, flexible, and easily processed, containing very fine tungsten powder at as much as 80% by weight. The purpose of this study was to investigate the dosimetric changes due to TFP shielding for electron beams. TFP (thickness 0-15mm) was placed on water or a water-equivalent phantom. Percentage depth ionization and transmission were measured for 4, 6, and 9MeV electron beams. Off-center ratio was also measured using film dosimetry at depth of dose maximum under similar conditions. Then, beam profiles and transmission with two shielding materials, TFP and lead, were evaluated. Reductions of 95% by using TFP at 0.5cm depth occurred at 4, 9, and 15mm with 4, 6, and 9MeV electron beams, respectively. It is found that the dose tend to increase at the field edge shaped with TFP, which might be influenced by the thickness. TFP has several unique features and is very promising as a useful tool for radiation protection for electron beams, among others.

  9. Status of the 1 MeV Accelerator Design for ITER NBI

    SciTech Connect

    Kuriyama, M.; Boilson, D.; Hemsworth, R.; Svensson, L.; Graceffa, J.; Schunke, B.; Decamps, H.; Tanaka, M.; Bonicelli, T.; Masiello, A.

    2011-09-26

    The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D{sup -} at 1 MeV for 3600 sec. In order to realize the beam source, design and R and D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

  10. Third Order Optical Nonlinearity of Colloidal Metal Nanoclusters Formed by MeV Ion Implantation

    NASA Technical Reports Server (NTRS)

    Sarkisov, S. S.; Williams, E.; Curley, M.; Ila, D.; Venkateswarlu, P.; Poker, D. B.; Hensley, D. K.

    1997-01-01

    We report the results of characterization of nonlinear refractive index of the composite material produced by MeV Ag ion implantation of LiNbO(sub 3) crystal (z-cut). The material after implantation exhibited a linear optical absorption spectrum with the surface plasmon peak near 430 nm attributed to the colloidal silver nanoclusters. Heat treatment of the material at 500 deg C caused a shift of the absorption peak to 550 nm. The nonlinear refractive index of the sample after heat treatment was measured in the region of the absorption peak with the Z-scan technique using a tunable picosecond laser source (4.5 ps pulse width).The experimental data were compared against the reference sample made of MeV Cu implanted silica with the absorption peak in the same region. The nonlinear index of the Ag implanted LiNbO(sub 3) sample produced at five times less fluence is on average two times greater than that of the reference.

  11. MeV electron acceleration by sub-terawatt laser pulses in near critical density plasmas

    NASA Astrophysics Data System (ADS)

    Goers, Andy; Hine, George; Feder, Linus; Miao, Bo; Salehi, Fatholah; Milchberg, Howard

    2015-11-01

    We demonstrate laser-plasma acceleration of high charge electron beams to the 10 MeV scale using ultrashort laser pulses with as little energy as 10 mJ. This result is made possible by an extremely dense and thin hydrogen gas jet where even sub-terawatt laser pulses are well above the critical power for relativistic self-focusing, and the 10 mJ pulses can drive a self-modulated wakefield accelerator. Total charge up to 0.5 nC is measured for energies >1 MeV. Acceleration is correlated to the presence of an intense, coherent, broadband light flash, associated with wavebreaking, which can radiate more than 3% of the laser energy in a sub-femtosecond bandwidth consistent with half-cycle optical emission. Our results enable truly portable applications of laser-driven acceleration, such as low dose radiography, ultrafast probing of matter, and isotope production. This work supported by DTRA and the US Department of Energy.

  12. Status of the 1 MeV Accelerator Design for ITER NBI

    NASA Astrophysics Data System (ADS)

    Kuriyama, M.; Boilson, D.; Hemsworth, R.; Svensson, L.; Graceffa, J.; Schunke, B.; Decamps, H.; Tanaka, M.; Bonicelli, T.; Masiello, A.; Bigi, M.; Chitarin, G.; Luchetta, A.; Marcuzzi, D.; Pasqualotto, R.; Pomaro, N.; Serianni, G.; Sonato, P.; Toigo, V.; Zaccaria, P.; Kraus, W.; Franzen, P.; Heinemann, B.; Inoue, T.; Watanabe, K.; Kashiwagi, M.; Taniguchi, M.; Tobari, H.; De Esch, H.

    2011-09-01

    The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D- at 1 MeV for 3600 sec. In order to realize the beam source, design and R&D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

  13. Neutron-deuteron analyzing power data at En=22.5 MeV

    NASA Astrophysics Data System (ADS)

    Weisel, G. J.; Tornow, W.; Crowell, A. S.; Esterline, J. H.; Hale, G. M.; Howell, C. R.; O'Malley, P. D.; Tompkins, J. R.; Witała, H.

    2014-05-01

    We present measurements of n-d analyzing power, Ay(θ), at En=22.5 MeV. The experiment uses a shielded neutron source which produced polarized neutrons via the 2H(d⃗,n⃗)3He reaction. It also uses a deuterated liquid-scintillator center detector and six pairs of liquid-scintillator neutron side detectors. Elastic neutron scattering events are identified by using time-of-flight techniques and by setting a window in the center detector pulse-height spectrum. The beam polarization is monitored by using a high-pressure helium gas cell and an additional pair of liquid-scintillator side detectors. The n-d Ay(θ) data were corrected for finite-geometry and multiple-scattering effects using a Monte Carlo simulation of the experiment. The 22.5-MeV data demonstrate that the three-nucleon analyzing power puzzle also exists at this energy. They show a significant discrepancy with predictions of high-precision nucleon-nucleon potentials alone or combined with Tucscon-Melbourne or Urbana IX three-nucleon forces, as well as currently available effective-field theory based potentials of next-to-next-to-next-to-leading order.

  14. A gas ionisation Direct-STIM detector for MeV ion microscopy

    NASA Astrophysics Data System (ADS)

    Norarat, Rattanaporn; Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef; Roux, Adrien; Stoppini, Luc; Whitlow, Harry J.

    2015-04-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger-Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas.

  15. Measurement of 14 MeV neutrons at TFTR with Si-diode detectors

    SciTech Connect

    Ruskov, E.; Heidbrink, W.W.; Duong, H.H.; Roquemore, A.L.; Strachan, J.D. )

    1995-01-01

    A detector system based on partially depleted silicon surface barrier detectors and fast front-end electronics has been built and cross calibrated to a set of absolutely calibrated [sup 4]He recoil detectors. The cross-calibration factor for the channel with the widest dynamic range is 2.5[times]10[sup [minus]13] counts per 14 MeV source neutron. These data agree well with the independent neutron activation data. The new detector system covers a large dynamic range (corresponding to 10[sup 13]--10[sup 18] neutrons/s). The response is linear, except at the highest count rates where the detector dead time ([similar to]200 ns) causes departure from linearity. The noise discrimination against 2.5 MeV neutrons and [gamma] pileup is excellent. Measurements of D-T neutrons from a tritium gas puff experiment as well as from a high-power D-T discharge in the TFTR tokamak are presented.

  16. Total and Capture Cross Sections of Dysprosium Isotopes up to 20 MeV

    SciTech Connect

    Lee, Y.D.; Oh, S.Y.; Chang, J.H.

    2005-11-15

    Neutron data for total and capture cross sections were evaluated on {sup 160}Dy, {sup 161}Dy, {sup 162}Dy, {sup 163}Dy, and {sup 164}Dy up to 20 MeV. The resolved resonance parameters were adopted from the Mughabghab compilation, but one bound level resonance for each isotope except {sup 162}Dy was invoked to reproduce the reference thermal cross sections. The average resonance parameters for s-wave neutrons were obtained from the analysis of the statistical behavior of resolved resonance parameters. Recent measurements of the capture cross sections were taken into account in adjusting the average resonance parameters for p- and d-waves. From the first excited energy to 20 MeV, the optical model, Hauser-Feshbach model, and quantum mechanical models were used to produce total, elastic scattering, and capture cross sections. The energy-dependent optical model potential was decided based on the recent experimental data. The calculated cross sections were in good agreement with the experimental data. The present evaluation resulted in improvement over the ENDF/B-VI.7 code.

  17. LET spectrometry of 14 MeV (D-T) neutrons using CR-39 track detectors

    NASA Astrophysics Data System (ADS)

    Sahoo, G. S.; Tripathy, S. P.; Sunil, C.; Sarkar, P. K.

    2013-04-01

    Linear energy transfer (LET) spectrum in water in the range of 12 keV/μm to 382 keV/μm due to 14 MeV (D-T) neutrons is estimated using the track size parameters in two different types of CR-39 track detectors, viz. Intercast (1.5 mm) and Pershore (0.5 mm). Another set of CR-39s (Intercast) combined with 1 mm polyethylene (PE) radiators is exposed to study the effect of enhanced recoils on the LET spectrum. The detection efficiencies for all these cases and the enhancement ratio due to PE radiator are determined. Using this LET spectrum, the microdosimetric spectra of absorbed doses and dose equivalents are estimated based on the Q-L conversion factors as given in ICRP 60. The shape of the LET spectra are found to be similar in all the cases, however, the dose equivalents obtained with the CR-39+PE radiator is about 20% more than the other detectors without PE. The ratios of dose equivalents obtained from LET spectra (HLET) and the ambient dose equivalent (H*(10)) obtained from fluence-to-dose equivalent conversion factors (ICRP 74) for 14 MeV neutrons are used to estimate the dose response of the detectors. H*(10) is also measured using a neutron rem meter, the response of which is found to be about 23% less than the actual dose.

  18. MeV ion beam lithography of biocompatible halogenated Parylenes using aperture masks

    NASA Astrophysics Data System (ADS)

    Whitlow, Harry J.; Norarat, Rattanaporn; Roccio, Marta; Jeanneret, Patrick; Guibert, Edouard; Bergamin, Maxime; Fiorucci, Gianni; Homsy, Alexandra; Laux, Edith; Keppner, Herbert; Senn, Pascal

    2015-07-01

    Parylenes are poly(p-xylylene) polymers that are widely used as moisture barriers and in biomedicine because of their good biocompatibility. We have investigated MeV ion beam lithography using 16O+ ions for writing defined patterns in Parylene-C, which is evaluated as a coating material for the Cochlear Implant (CI) electrode array, a neuroprosthesis to treat some forms of deafness. Parylene-C and -F on silicon and glass substrates as well as 50 μm thick PTFE were irradiated to different fluences (1 ×1013 - 1 ×1016 1 MeV 16O+ ions cm-2) through aperture masks under high vacuum and a low pressure (<10-3 mbar) oxygen atmosphere. Biocompatibility of the irradiated and unirradiated surfaces was tested by cell-counting to determine the proliferation of murine spiral ganglion cells. The results reveal that an oxygen ion beam can be used to pattern Parylene-C and -F without using a liquid solvent developer in a similar manner to PTFE but with a ∼25× smaller removal rate. Biocompatibility tests showed no difference in cell adhesion between irradiated and unirradiated areas or ion fluence dependence. Coating the Parylene surface with an adhesion-promoting protein mixture had a much greater effect on cell proliferation.

  19. Dosimetric shield evaluation with tungsten sheet in 4, 6, and 9MeV electron beams.

    PubMed

    Fujimoto, Takahiro; Monzen, Hajime; Nakata, Manabu; Okada, Takashi; Yano, Shinsuke; Takakura, Toru; Kuwahara, Junichi; Sasaki, Makoto; Higashimura, Kyoji; Hiraoka, Masahiro

    2014-11-01

    In electron radiotherapy, shielding material is required to attenuate beam and scatter. A newly introduced shielding material, tungsten functional paper (TFP), has been anticipated to become a very useful device that is lead-free, light, flexible, and easily processed, containing very fine tungsten powder at as much as 80% by weight. The purpose of this study was to investigate the dosimetric changes due to TFP shielding for electron beams. TFP (thickness 0-15mm) was placed on water or a water-equivalent phantom. Percentage depth ionization and transmission were measured for 4, 6, and 9MeV electron beams. Off-center ratio was also measured using film dosimetry at depth of dose maximum under similar conditions. Then, beam profiles and transmission with two shielding materials, TFP and lead, were evaluated. Reductions of 95% by using TFP at 0.5cm depth occurred at 4, 9, and 15mm with 4, 6, and 9MeV electron beams, respectively. It is found that the dose tend to increase at the field edge shaped with TFP, which might be influenced by the thickness. TFP has several unique features and is very promising as a useful tool for radiation protection for electron beams, among others. PMID:24953537

  20. Comparing Solar-Flare Acceleration of >-20 MeV Protons and Electrons Above Various Energies

    NASA Technical Reports Server (NTRS)

    Shih, Albert Y.

    2010-01-01

    A large fraction (up to tens of percent) of the energy released in solar flares goes into accelerated ions and electrons, and studies indicate that these two populations have comparable energy content. RHESSI observations have shown a striking close linear correlation between the 2.223 MeV neutron-capture gamma-ray line and electron bremsstrahlung emission >300 keV, indicating that the flare acceleration of >^20 MeV protons and >300 keV electrons is roughly proportional over >3 orders of magnitude in fluence. We show that the correlations of neutron-capture line fluence with GOES class or with bremsstrahlung emission at lower energies show deviations from proportionality, primarily for flares with lower fluences. From analyzing thirteen flares, we demonstrate that there appear to be two classes of flares with high-energy acceleration: flares that exhibit only proportional acceleration of ions and electrons down to 50 keV and flares that have an additional soft, low-energy bremsstrahlung component, suggesting two separate populations of accelerated electrons. We use RHESSI spectroscopy and imaging to investigate a number of these flares in detail.

  1. Thick photoresist outgassing during MeV implantation (mechanism & impact on production)

    SciTech Connect

    Lee, W.J.; Tokoro, N.; Cho, H.T.

    1996-12-31

    The generation of an ion beam and its impact into photoresist-masked wafers will have an adverse effect on the vacuum of an MeV ion implanter. This is particularly significant when implanting with higher energies and higher beam current through the thick photoresist. In this paper, we will present the mechanism and effects of photoresist outgassing caused by high energy ion implantation (250KeV to 3 MeV). Due to photoresist outgassing and its effects, production usable beam current on small process chamber can be significantly limited. Photoresist outgassing from various implant conditions will be discussed. Photoresist of various thicknesses up to 4.5um from several vendors and both positive and negative acting resists were compared. Both ionization (electron stripping) and neutralization (electron addition) were measured as dose shift (underdose or overdose) using TW and Rs analysis. Depending on the ion species, energy and beam current, chamber pressure rises. The pressure rise could be as high as in the E-4 torr range. If the chamber pressure is kept below 3.0E-5 torr no observable dose shift could be detected.

  2. The solar gamma ray spectrum between 4 and 8 MeV

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Suri, A. N.

    1976-01-01

    The properties of nuclear gamma ray emission in the 4 to 8 MeV range were evaluated. This emission consists of broad and narrow lines resulting from nuclear reactions of energetic H, He, C and O nuclei with ambient matter. Calculations were compared with observations of the 1972, August 4 flare and show that: (1) essentially all the observed radiation in the 4 to 8 MeV region is to the superposition of broad and narrow lines of nuclear origin with almost no contribution from other mechanisms; (2) the accelerated particles in the energy region from about 10 to 100 MeV/amu have a relatively flat Energy spectrum; (3) the calculated gamma ray spectrum, obtained from an isotropic distribution of accelerated particles, fits the observed spectrum better than the spectrum derived from an anisotropic distribution for which the particles' velocity vectors point towards the photosphere; and (4) it is possible to set a stringent upper limit on the ratio of relativistic electrons to protons in flares, consistent with the small, but finite, electron-to-proton ratio in galactic cosmic rays.

  3. Polarized-target asymmetry in pion-proton bremsstrahlung at 298 MeV

    SciTech Connect

    Bosshard, A.; Amsler, C.; Bistirlich, J.A.; van den Brandt, B.; Crowe, K.M.; Doebeli, M.; Doser, M.; Haddock, R.P.; Konter, J.A.; Ljungfelt, S.; Loude, J.F.; Mango, S.; Meyer, C.A.; Perroud, J.P.; Riedlberger, J.; Renker, D.; Schaad, M.; Sober, D.I.; Truoel, P.; Weymuth, P. Lawrence Berkeley Laboratory, University of California at Berkeley, Berkeley California 94720 Paul Scherrer Institut, 5232 Villigen, Paul Scherrer Institut, Department of Physics, University of California at Los Angeles, Los Angeles, California 90024 Institut de Physique Nucleaire, Universite de Lausanne, 1015 Lausanne, Department of Physics, Catholic University of America, Washington, D.C. 10024 )

    1990-05-28

    First data are presented for the polarized-target asymmetry in the reaction {pi}{sup +}{ital p}{r arrow}{pi}{sup +}{ital p}{gamma} at an incident pion energy of 298 MeV. The geometry was chosen to maximize the sensitivity to the radiation of the magnetic dipole moment {mu}{sub {Delta}} of the {Delta}{sup ++}(1232 MeV). A fit of the asymmetry in the cross section {ital d}{sup 5}{sigma}/{ital d}{Omega}{sub {pi}} {ital d}{Omega}{sub {gamma}} {ital dk} as a function of the photon energy {ital k} to predictions from a recent isobar-model calculation with {mu}{sub {Delta}} as the only free parameter yields {mu}{sub {Delta}}=1.64({plus minus}0.19exp{Delta},{plus minus}0.14 theor){mu}{sub {ital p}}. Though this value agrees with bag-model corrections to the SU(6) prediction {mu}{sub {Delta}}=2{mu}{sub {ital p}}, further clarifications on the model dependence of the result are needed, in particular since the isobar model fails to describe both the cross section and the asymmetry at the highest photon energies.

  4. 10 MeV Electron Beam Test Using Gas Electron Multiplier (GEM) Detectors

    NASA Astrophysics Data System (ADS)

    Hahn, C. H.; Kim, I. G.; Park, S. T.; Kim, W. J.; Yoo, D. S.; Moon, B. S.; Ha, S. Y.; Ahn, B. J.; Ha, Y. J.; Jung, C. Y.; Jung, S. H.; Cho, B. H.; Lee, B. C.; Han, Y. H.; Chung, C. E.; Li, J.; White, A. P.; Yu, J.

    2006-10-01

    10 MeV electron beam has been tested using a single channel double gas electron multiplier (GEM) detector constructed by Changwon National University and a multi-channel double GEM chamber by the University of Texas at Arlington. It has been demonstrated that both detectors are able to detect signals generated by high energy electrons as well as x-rays. By analyzing the chamber output signals captured by oscilloscope, it is believed that the x-ray was produced by bremsstrahlung while electrons were decelerating in a 2 mm lead plate. The time profile of the KAERI's 10 MeV electron beam bunches was determined based on the calculated angular distribution of electrons by multiple scattering in the lead plate. Furthermore, the spatial electron density distribution has been extrapolated by using the time profile. The effective gain of the GEM chamber has been estimated by analyzing the measured output currents of the chamber. It is important that the time and spatial profiles of the high energy electron beam could be determined using GEM detectors, which suggests that GEM might have an application as a calorimeter for a large scale accelerator. Details of experimental procedure will be discussed.

  5. Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy

    SciTech Connect

    Inoue, Yoshiyuki; Murase, Kohta; Madejski, Grzegorz M.; Uchiyama, Yasunobu

    2013-09-24

    While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10-12 erg/cm2/s-1 at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

  6. Rederivation of MHV and MEV antibody positive mice by cross-fostering and use of the microisolator caging system.

    PubMed

    Lipman, N S; Newcomer, C E; Fox, J G

    1987-04-01

    This study established the feasibility of rederiving numerous mouse hepatitis virus (MHV) and mouse encephalomyelitis virus (MEV) antibody positive strains of mice using cross fostering techniques and a new caging system, thus permitting introduction of virus antibody free mice into a barrier facility. Serologic status of dams within the nucleus breeding colony was determined, and all mice within the breeding colony were housed in individual Microisolator cages. Specific pathogen free (SPF) foster mothers purchased from a commercial source were determined to have no detectable serum antibody to 11 murine viruses including MEV and MHV. Pups delivered naturally from time pregnant dams were cross fostered onto the SPF foster dams. The procedure of cross fostering was conducted within a positive flow, HEPA-filtered, mass air displacement unit within 24 hours of parturition. The virus status of pups from 49 litters was monitored serologically at weaning and again at 6 weeks of age. All cross fostered litters were serologically negative for antibody to mouse hepatitis virus. Seven of 29 litters were negative for MEV antibody titer using this cross fostering technique. Those litters negative serologically to both MHV and MEV (at 3 and 6 weeks) were transferred to a barrier facility and held in isolation. All rederived mice transferred to the barrier facility remained negative for MHV and MEV when sampled at 12 weeks of age.

  7. The Rhodotron, a new 10 MeV, 100 kW, cw metric wave electron accelerator

    NASA Astrophysics Data System (ADS)

    Jongen, Y.; Abs, M.; Genin, F.; Nguyen, A.; Capdevila, J. M.; Defrise, D.

    1993-06-01

    New applications for high energy, high current electron beam processing are continually expanding. Today, however, 10 MeV rf electron linacs are frequently limited to an average beam power of only 20 or 30 kW. To achieve higher beam power, CW operation and the use of lower frequencies are necessary. In the last years, the principle for a new kind of electron accelerator was developed by the Atomic Energy Agency (CEA) in France. This accelerator is based on the principle of recirculating a beam throughout a single coaxial cavity resonating in metric waves. A 3.3 MeV, 4 mA prototype has been built and successfully tested. The industrial accelerator developed by IBA in collaboration with the CEA is a 10 MeV, 100 kW beam power unit with an additional beam exit at 5 MeV. The cavity, made of copper-plated steel, will resonate at 107.5 MHz. A rf power of 100 kW is needed to produce an electric field allowing an energy gain of 1 MeV per crossing. In addition, 100 kW of power is needed for acceleration. The 200 kW output amplifier uses a 100 kW plate dissipation tetrode (TH 681 from Thomson-CSF) in a grounded grid configuration. In this paper, the design of the new model as well as the prototype manufacturing schedule are presented in more detail.

  8. Modification of radiobiological effects of 171 MeV protons by elements of physical protection

    NASA Astrophysics Data System (ADS)

    Bulinina, Taisia; Shurshakov, Vyacheslav; Ivanov, Alexander; Molokanov, Alexander

    2016-07-01

    Space radiation includes protons of various energies. Physical protection is effective in the case of low energy protons (50-100 MeV) and becomes insufficient for radiation with a high part of high-energy protons. In the experiment performed on outbred mice, the purpose of the study was to evaluate the radiobiological effect of 171 MeV protons and protons modified by elements of physical protection of the spacecraft, on a complex of indicators of the functional condition of the system hematopoiesis and the central nervous system in 24 hours after irradiation at 20 cGy dose. The spacecraft radiation protection elements used in the experiment were a construction of wet hygiene wipes called a «protective curtain», and a glass plate imitating an ISS window. Mass thickness of the " protective curtain" in terms of water equivalent was ̴ 6,2 g/cm2. Physical shielding along the path of 171 MeV protons increases their linear energy transfer leading to the absorbed dose elevation and strengthening of the radiobiological effect. In the experiment, the two types of shielding together raised the absorbed dose from 20 to 23.2 cGy. Chemically different materials (glass and water in the wipes) were found to exert unequal modifying effects on physical and biological parameters of the proton-irradiated mice. There was a distinct dose-dependent reduction of bone marrow cellularity within the dose range from 20 cGy to 23.2 cGy in 24 hours after exposure. No modifying effect of the radiation protection elements on spontaneous motor activity was discovered when compared with entrance protons. The group of animals protected by the glass plate exhibited normal orientative-trying reactions and weakened grip with the forelimbs. The effects observed in the experiment indicate the necessity to carry out comprehensive radiobiological researches (physical, biological and mathematical) in assessing the effects of physical protection, that are actual for ensuring radiation safety of crews in

  9. Deuteron-induced reactions on Ni isotopes up to 60 MeV

    NASA Astrophysics Data System (ADS)

    Avrigeanu, M.; Šimečková, E.; Fischer, U.; Mrázek, J.; Novak, J.; Štefánik, M.; Costache, C.; Avrigeanu, V.

    2016-07-01

    Background: The high complexity of the deuteron-nucleus interaction from the deuteron weak binding energy of 2.224 MeV is also related to a variety of reactions induced by the deuteron-breakup (BU) nucleons. Thus, specific noncompound processes as BU and direct reactions (DR) make the deuteron-induced reactions so different from reactions with other incident particles. The scarce consideration of only pre-equilibrium emission (PE) and compound-nucleus (CN) mechanisms led to significant discrepancies with experimental results so that recommended reaction cross sections of high-priority elements as, e.g., Ni have mainly been obtained by fit of the data. Purpose: The unitary and consistent BU and DR account in deuteron-induced reactions on natural nickel may take advantage of an extended database for this element, including new accurate measurements of particular reaction cross sections. Method: The activation cross sections of 64,61,60Cu, Ni,5765, and 55,56,57,58,59m,60Co nuclei for deuterons incident on natural Ni at energies up to 20 MeV, were measured by the stacked-foil technique and high-resolution gamma spectrometry using U-120M cyclotron of CANAM, NPI CAS. Then, within an extended analysis of deuteron interactions with Ni isotopes up to 60 MeV, all processes from elastic scattering until the evaporation from fully equilibrated compound system have been taken into account while an increased attention is paid especially to the BU and DR mechanisms. Results: The deuteron activation cross-section analysis, completed by consideration of the PE and CN contributions corrected for decrease of the total-reaction cross section from the leakage of the initial deuteron flux towards BU and DR processes, is proved satisfactory for the first time to all available data. Conclusions: The overall agreement of the measured data and model calculations validates the description of nuclear mechanisms taken into account for deuteron-induced reactions on Ni, particularly the BU and

  10. Exclusive measurements of light fragment production at forward angles in Ne-Pb and Ne-NaF collisions at E/A=400 MeV and 800 MeV

    NASA Technical Reports Server (NTRS)

    Bastid, N.; Alard, J. P.; Arnold, J.; Augerat, J.; Babinet, R.; Biagi, F.; Brochard, F.; Crouau, M.; Charmensat, P.; Dupieux, P.; et, a. l.; Schimmerling, W. (Principal Investigator)

    1990-01-01

    Emission of light fragments at small angles is studied in relativistic heavy ion collisions using the Diogene plastic wall for both symmetrical and non-symmetrical target-projectile systems with 400 MeV per nucleon and 800 MeV per nucleon incident neon nuclei. Efficiency of multiplicity measurements in the small angle range for the selection of central or peripheral collisions is confirmed for asymmetric systems. Differential production cross sections of Z = 1 fragments show evidence for the existence of two emitting sources. The apparent temperature of each source is obtained from comparison with a thermodynamical model.

  11. SAS-2 observations of celestial diffuse gamma radiation above 30 MeV

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    The small astronomy satellite, SAS-2, used a 32-deck magnetic core digitized spark chamber to study gamma rays with energies above 30 MeV. Data for four regions of the sky away from the galactic plane were analyzed. These regions show a finite, diffuse flux of gamma rays with a steep energy spectrum, and the flux is uniform over all the regions. Represented by a power law, the differential energy spectrum shows an index of 2.5 + or - 0.4. The steep SAS-2 spectrum and the lower energy data are reasonably consistent with a neutral pion gamma-ray spectrum which was red-shifted (such as that proposed by some cosmological theories). It is concluded that the diffuse celestial gamma ray spectrum observed presents the possibility of cosmological studies and possible evidence for a residual cosmic ray density, and supports the galactic superclusters of matter and antimatter remaining from baryon-symmetric big bang.

  12. SAS 2 observations of the earth albedo gamma radiation above 35 MeV

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Simpson, G. A.; Ozel, M. E.

    1981-01-01

    The earth albedo gamma radiation above 35 MeV in the equatorial region is investigated using observations from the second Small Astronomy Satellite. The zenith angle distribution of the gamma radiation has a peak toward the horizon which is about an order of magnitude more intense than the radiation coming from the nadir, and nearly two orders of magnitude more intense than the gamma radiation from most parts of the sky. The gamma radiation originating from the western horizon is a factor of four more intense than the radiation from the eastern horizon and a factor of three more intense than that from the northern and southern directions. This reflects the geomagnetic effects on the incident cosmic rays whose interactions produce the albedo gamma rays. The variation of the upcoming gamma ray intensity with vertical cutoff rigidity is consistent with the empirical relationship found by Gur'yan et al. (1979).

  13. Study of imaging plate detector sensitivity to 5-18 MeV electrons

    SciTech Connect

    Boutoux, G. Rabhi, N.; Batani, D.; Ducret, J.-E.; Binet, A.; Nègre, J.-P.; Reverdin, C.; Thfoin, I.; Jakubowska, K.

    2015-11-15

    Imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. We calibrated at the ELSA electron beam facility (CEA DIF) the five different available types of IPs (namely, MS-SR-TR-MP-ND) to electrons from 5 to 18 MeV. In the context of diagnostic development for the PETawatt Aquitaine Laser (PETAL), we investigated the use of stacks of IP in order to increase the detection efficiency and get detection response independent from the neighboring materials such as X-ray shielding and detector supports. We also measured fading functions in the time range from a few minutes up to a few days. Finally, our results are systematically compared to GEANT4 simulations in order to provide a complete study of the IP response to electrons over the energy range relevant for PETAL experiments.

  14. Radiation stability of ZrN under 2.6 MeV proton irradiation

    NASA Astrophysics Data System (ADS)

    Yang, Yong; Dickerson, Clayton A.; Allen, Todd R.

    2009-07-01

    Zirconium nitride is a promising alternative material for the use as an inert matrix for transuranic fuel, but the knowledge of the radiation tolerance of ZrN is very limited. We have studied the radiation stability of ZrN using a 2.6 MeV proton beam at 800 °C. The irradiated microstructure and hardening were investigated and compared with annealed samples. A high density of nano-sized defects was observed in samples irradiated to doses of 0.35 and 0.75 dpa. Some defects were identified as vacancy-type pyramidal dislocation loops using lattice resolution imaging and Fourier-filter image processing. A very slight lattice expansion was noted for the sample with a dose of 0.75 dpa. Hardening effects were found for samples irradiated to both 0.35 and 0.75 dpa using Knoop indentation.

  15. X-Ray Radar Imaging Technique Using a 2 Mev Linear Electron Accelerator

    NASA Astrophysics Data System (ADS)

    Dreesen, W.; Schwellenbach, D.; Wood, J. R.; Browder, M.; Kallas, N.; Potter, J.

    X-ray radar imaging combines standard radar techniques with the penetration power of X-rays to image scenes. Our project strives to demonstrate the technique using a 2-MeV linear electron accelerator to generate the S-band--modulated X-ray signals. X-ray detectors such as photodiodes and scintillators are used to detect the signals in backscatter and transmission detection schemes. The S-band microstructure is imposed on the variable width electron pulse and this modulation carries over to the bremsstrahlung X-rays after the electron beam is incident upon a copper-tungsten alloy target. Using phase/distance calculations and a low-jitter system, we expect to detect different object distances by comparing the measured phase differences. The experimental setup, which meets strict jitter requirements, and preliminary experimental results are presented.

  16. Fixed fluorescent images of an 80 MeV proton pencil beam

    NASA Astrophysics Data System (ADS)

    Warman, J. M.; de Haas, M. P.; Luthjens, L. H.; Denkova, A. G.; Kavatsyuk, O.; van Goethem, M.-J.; Kiewiet, H. H.; Brandenburg, S.

    2013-04-01

    We have used an organic radio-fluorogenic gel to make fixed fluorescent images of the track of an 80 MeV proton pencil beam NB this is not a scintillation effect; rather a small fraction of the molecules of the medium are converted permanently from a non-emissive to an emissive form. The spatial resolution of the images is better than 0.1 mm and the cuboid form of the gels allows the track to be viewed along the direction of the beam or transverse to it. The fluorescence diverges and increases in intensity with increasing depth up to the Bragg peak with 80-20% post-peak fall-off in 1.4±0.1 mm. From the effect of interposed polystyrene sheets on the proton range in the gel, its water equivalent thickness is determined to be 0.91.

  17. Fabrication of waveguides in Yb:YCOB crystal by MeV oxygen ion implantation

    NASA Astrophysics Data System (ADS)

    Jiao, Yang; Chen, Feng; Wang, Xue-Lin; Wang, Ke-Ming; Wang, Lei; Wang, Liang-Ling; Zhang, Huai-Jin; Lu, Qing-Ming; Ma, Hong-Ji; Nie, Rui

    2007-07-01

    Oxygen ions with energies of 6.0 or 3.0 MeV were implanted into y-cut Yb:YCOB crystals at fluences ranging from 5.0 × 10 13 to 2.0 × 10 15 ions/cm 2 at room temperature, forming optical planar waveguide structures. Dark-mode line spectroscopy was applied at two wavelengths, 633 and 1539 nm, in various excitation configurations, showing strong enhancement of one of the indices ( nx) in the implanted near surface. The nx refractive index profile is reconstructed by a reflectivity calculation method and compared to the ion energy losses profiles deduced from SRIM-code simulation. Moreover, the near-field patterns were imaged by an end-fire coupling arrangement.

  18. Seed population for about 1 MeV per nucleon heavy ions accelerated by interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Tan, L. C.; Mason, G. M.; Klecker, B.; Hovestadt, D.

    1989-01-01

    Data obtained between 1977 and 1982 by the ISEE 1 and ISEE 3 satellites on the composition of heavy ions of about 1 MeV per nucleon, accelerated in interplanetary shock events which followed solar flare events, are examined. It was found that the average relative abundances for C, O, and Fe in the shock events were very close to those found for energetic ions in the solar flares, suggesting that, at these energies, the shock accelerated particles have the solar energetic particles as their seed population. This hypothesis is supported by the fact that the Fe/O ratio in the solar particle events is very strongly correlated with the Fe/O ratio in associated diffusive shock events.

  19. Ion shaking in the 200 MeV XLS-ring

    SciTech Connect

    Bozoki, E.; Kramer, S.L.

    1992-12-31

    It has been shown that ions, trapped inside the beam`s potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H{sub 2} to CO{sub 2}) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied.

  20. Ion shaking in the 200 MeV XLS-ring

    SciTech Connect

    Bozoki, E.; Kramer, S.L.

    1992-01-01

    It has been shown that ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H[sub 2] to CO[sub 2]) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied.

  1. Activation cross sections for reactions induced by 14 MeV neutrons on natural tantalum

    SciTech Connect

    Luo Junhua; Tuo Fei; Kong Xiangzhong

    2009-05-15

    Cross sections for (n,2n), (n,p), (n,n{sup '}{alpha}), (n,t), (n,d{sup '}), and (n,{alpha}) reactions have been measured on tantalum isotopes at the neutron energies of 13.5 to 14.7 MeV using the activation technique. Data are reported for the following reactions: {sup 181}Ta(n,2n){sup 180}Ta{sup g}, {sup 181}Ta(n,p){sup 181}Hf, {sup 181}Ta(n,n{sup '}{alpha}){sup 177}Lu{sup m}, {sup 181}Ta(n,t){sup 179}Hf{sup m2}, {sup 181}Ta(n,d{sup '}){sup 180}Hf{sup m}, and {sup 181}Ta(n,{alpha}){sup 178}Lu{sup m}. The neutron fluences were determined using the monitor reaction {sup 27}Al(n,{alpha}){sup 24}Na. Results were discussed and compared with the previous works.

  2. Effect of MeV nitrogen ion implantation on the resistivity transition in Czochralski silicon wafers

    NASA Astrophysics Data System (ADS)

    Moon, Byeong-Sam; Lee, In-Ji; Park, Jea-Gun

    2012-12-01

    We investigated how MeV nitrogen ion implantation affects the resistivity transition in Czochralski (CZ) silicon wafers. After annealing at 800 °C for 20 h and again at 1000 °C for 10 h, the implanted nitrogen atoms accumulated in the projected range (R P ) for ion doses less than 5 × 1014 cm-2 whereas they accumulated at both R P /2 and R P at ion doses above 3 × 1015 cm-2. These results indicate that no resistivity transition was found at nitrogen ion doses less than 5 × 1013 cm-2 whereas n-/p or n+/p resistivity transition was shown at ion doses higher than 5 × 1014 cm-2. Many fewer than 1% of the implanted nitrogen atoms were ionized after the heat treatment. Thus, the resistivity of nitrogen-doped silicon wafers is more than 100 times higher than that of phosphorous-doped silicon wafers.

  3. Turbulent transport of MeV range cyclotron heated minorities as compared to alpha particles

    NASA Astrophysics Data System (ADS)

    Pusztai, István; Wilkie, George J.; Kazakov, Yevgen O.; Fülöp, Tünde

    2016-11-01

    We study the turbulent transport of an ion cyclotron resonance heated (ICRH), MeV range minority ion species in tokamak plasmas. Such highly energetic minorities, which can be produced in the three ion minority heating scheme (Kazakov et al (2015) Nucl. Fusion 55 032001), have been proposed to be used to experimentally study the confinement properties of fast ions without the generation of fusion alphas. We compare the turbulent transport properties of ICRH ions with that of fusion born alpha particles. Our theoretical predictions indicate that care must be taken when conclusions are drawn from experimental results: while the effect of turbulence on these particles is similar in terms of transport coefficients, differences in their distribution functions—ultimately their generation processes—make the resulting turbulent fluxes different.

  4. Activation cross sections for reactions induced by 14 MeV neutrons on natural ruthenium

    NASA Astrophysics Data System (ADS)

    Luo, Junhua; Liu, Gang; Tuo, Fei; Kong, Xiangzhong; Liu, Rong; Jiang, Li; Lou, Benchao

    2007-11-01

    Cross sections for (n,2n), (n,p), (n,α), and (n,d*)1 reactions have been measured on ruthenium isotopes at the neutron energies of 13.5 to 14.8 MeV using the activation technique in combination with high-resolution gamma-ray spectroscopy. Data are reported for the following reactions: Ru104(n,2n)Ru103, Ru98(n,2n)Ru97, Ru96(n,2n)Ru95, Ru96(n,p)Tc96g, Ru96(n,p)Tc96m, Ru104(n,p)Tc104, Ru102(n,p)Tc102m, Ru104(n,α)Mo101, Ru102(n,α)Mo99, Ru96(n,α)Mo93m, and Ru96(n,d*)Tc95m. Results were discussed and compared with the previous works.

  5. M shell ionization of Ar induced in near-central collisions with MeV protons

    NASA Astrophysics Data System (ADS)

    Kavčič, M.; Banaś, D.

    2016-03-01

    High energy resolution {{K}}{β }{1,3} x-ray emission spectra of Ar induced in collisions with 0.75-3.0 MeV protons were measured using a complete in-vacuum curved-crystal x-ray emission spectrometer in Johansson geometry. The {{K}}{β }{1,3}{{{M}}}{1,2} satellite lines were clearly resolved in the measured spectra and their intensity relative to the parent {{K}}{β }{1,3} diagram line was used to extract the M shell single ionization probability for near-central collisions. The experimental values are compared to the theoretical predictions calculated within the semiclassical approximation (SCA) and also the binary encounter based geometrical model. Very good agreement with experimental data was achieved for the SCA values employing concise Dirac-Hartree-Fock wave functions for the description of valence M shell electrons.

  6. Filamentation control and collimation of laser accelerated MeV protons

    NASA Astrophysics Data System (ADS)

    Ramakrishna, B.; Tayyab, M.; Bagchi, S.; Mandal, T.; Upadhyay, A.; Weng, S. M.; Murakami, M.; Cowan, T. E.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2015-12-01

    We demonstrate experimentally that the proton beam filamentation in dense plasma can be controlled in multi-layered (Al-CH-Al) sandwich targets. We observe up to three-fold reduction in the MeV proton beam divergence (~12°) from these targets as a result of decrease in filamentary structures in the proton beam profile. Strong self-generated resistive magnetic fields in targets with a high-Z transport layer are mainly responsible for this observed effect. Enhancement in the proton flux and energy is also observed from these targets. Supported by a matching 2D particle-in-cell (PIC) simulation and theoretical considerations, we suggest that these targets can be very effectively implemented to collimate proton beams useful for ion oncology applications or advanced fast igniter approach of inertial confinement fusion (ICF).

  7. Response function stability of single crystal diamond detectors to 14 MeV neutrons

    SciTech Connect

    Zbořil, Miroslav Zimbal, Andreas

    2014-11-15

    Detectors based on single crystal synthetic diamond show promise as neutron spectrometers for the ITER project. In this work, the stability of the response function of two diamond detectors was tested at the Physikalisch-Technische Bundesanstalt (PTB) accelerator using a 14 MeV neutron field and a method of time-resolved fluence monitoring. In addition, measurements at the PTB ion-microbeam were made to investigate the charge collection properties of the detectors in more detail. The {sup 12}C(n,α){sup 9}Be peak response of one of the detectors was found to be stable within 1% after irradiation with a neutron fluence of 8 × 10{sup 9} cm{sup −2}. The absolute value of the peak response of this detector was determined as 8.65(26) × 10{sup −5} cm{sup 2}.

  8. Effects of 1- and 2-MeV electrons on photomultiplier tubes

    NASA Technical Reports Server (NTRS)

    Beatty, M. E., III; Debnam, W. J., Jr.; Meredith, B. D.

    1976-01-01

    Various types of photomultiplier tubes useful for space applications were irradiated with 1- and 2-MeV electrons at Van Allen radiation belt fluxes of 100,000 to 10 millions electrons/sq cm-sec. The increase in the dark current due to electron irradiation was observed at various bias voltages under worst-case conditions (no shielding). Results were presented in the form of dark current plotted against electron flux. All the tubes tested showed extremely large increases in dark current. Tube types 541A, 6217, 6199, and 6903 exhibited the largest increases under irradiation, whereas type 1P22 was affected the least. All the damage observed was transient. The luminescence produced in the optical window probably accounts for a large part of the dark-current increases, but there were some effects possibly due to direct irradiation of the photocathode and dynode chain.

  9. Microstructure and properties of TiB/sub 2/ implanted with 1-MeV nickel

    SciTech Connect

    McHargue, C.J.; Sklad, P.S.; Angelini, P. Lewis, M.B.

    1983-01-01

    Polycrystalline samples of TiB/sub 2/ were implanted at ambient temperatures with 1-MeV Ni/sup +/ ions to a fluence of 1 x 10/sup 17/ ions/cm/sup 2/. This fluence corresponds to a calculated nickel-to-titanium ratio, within the half width of the ion distribution, of approximately 0.12. Analytical electron microscopy was used to study the resultant microstructure. The starting microstructure was modified to a depth of approximately 750 nm, significantly deeper than the calculated peak in the deposited nickel profile of 389 nm. The results also show a change in the character of the microstructure, from one exhibiting a moderate density of tangled dislocations to a high density of small defects, as well as a change in the concentration of nickel as a function of depth from the implanted surface. There was no evidence of nickel precipitation. Surface mechanical properties such as hardness and wear resistance were significantly increased.

  10. Measurement of the angular distribution of neutron-proton scattering at 10 MeV

    SciTech Connect

    Haight, R.C.; Bateman, F.B.; Grimes, S.M.; Brient, C.E.; Massey, T.N.; Wasson, O.A.; Carlson, A.D.; Zhou, H.

    1995-12-31

    The relative angular distribution of neutrons scattered from protons was measured at an incident neutron energy of 10 MeV at the Ohio University Accelerator Laboratory. An array of 11 detector telescopes at laboratory angles of 0 to 60 degrees was used to detect recoil protons from neutron interactions with a CH{sub 2} (polypropylene) target. Data for 7 of these telescopes were obtained with one set of electronics and are presented here. These data, from 108 to 180 degrees for the center-of-mass scattering angles, have a small slope which agrees better with angular distributions predicted by the Arndt phase shifts than with the ENDF/B-VI angular distribution.

  11. Damage formation during 1.0 MeV Si self-implantation at low temperatures

    SciTech Connect

    Huang, M.B.; Mitchell, I.V.

    1999-04-01

    The effect of substrate temperature and ion flux on lattice damage in silicon induced by 1.0 MeV Si ion implantation has been investigated using Rutherford backscattering channeling (RBSC) and Raman spectroscopy. Over the temperature range of 77--323K, the temperature dependence of near-surface damage is found to be different from that of end-of-range damage. This may suggest that different mechanisms for damage growth are dominant along the ion path. The flux effect on damage accumulation varies with substrate temperatures. Around liquid nitrogen temperature (77K), the near-surface damage decreases with increasing flux, contrary to the case around room temperature (300K). In the temperature range of {approximately}120--250K, damage is almost independent of implant flux. Possible causes of the observed phenomena are discussed.

  12. Vector and tensor analyzing powers in deuteron-proton breakup at 130 MeV

    SciTech Connect

    Stephan, E.; Biegun, A.; Klos, B.; Micherdzinska, A.; Zipper, W.; Kistryn, St.; Sworst, R.; Bodek, K.; Ciepal, I.; Golak, J.; Skibinski, R.; Witala, H.; Wronska, A.; Zejma, J.; Deltuva, A.; Epelbaum, E.; Fonseca, A. C.; Kalantar-Nayestanaki, N.; Kis, M.; Mahjour-Shafiei, M.

    2010-07-15

    High-precision data for vector and tensor analyzing powers for the {sup 1}H(d-vector,pp)n reaction at a 130-MeV deuteron beam energy have been measured over a large part of the phase space. Theoretical predictions based on various approaches to describe the three nucleon (3N) system reproduce very well the vector analyzing power data and no three-nucleon force effect is observed for these observables. Tensor analyzing powers are also very well reproduced by calculations in almost the whole studied region, but locally certain discrepancies are observed. For A{sub xy} such discrepancies usually appear, or are enhanced, when model 3N forces, TM99 or Urbana, are included. Problems of all theoretical approaches with describing A{sub xx} and A{sub yy} are limited to very small kinematical regions, usually characterized by the lowest energy of the relative motion of the two protons.

  13. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    NASA Astrophysics Data System (ADS)

    Sathyanarayana Bhat, P.; Rao, Asha; Sanjeev, Ganesh; Usha, G.; Priya, G. Krishna; Sankaran, M.; Puthanveettil, Suresh E.

    2015-06-01

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5-100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance-frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 -1016 cm-3.

  14. Elastic scattering of 96 MeV neutrons from iron, yttrium, and lead

    SciTech Connect

    Oehrn, A.; Blomgren, J.; Andersson, P.

    2008-02-15

    Data on elastic scattering of 96 MeV neutrons from {sup 56}Fe, {sup 89}Y, and {sup 208}Pb in the angular interval 10-70 deg. are reported. The previously published data on {sup 208}Pb have been extended, as a new method has been developed to obtain more information from data, namely to increase the number of angular bins at the most forward angles. A study of the deviation of the zero-degree cross section from Wick's limit has been performed. It was shown that the data on {sup 208}Pb are in agreement with Wick's limit while those on the lighter nuclei overshoot the limit significantly. The results are compared with modern optical model predictions, based on phenomenology and microscopic nuclear theory. The data on {sup 56}Fe, {sup 89}Y, and {sup 208}Pb are in general in good agreement with the model predictions.

  15. Forward-angle neutron-proton scattering at 96 MeV

    SciTech Connect

    Johansson, C.; Blomgren, J.; Atac, A.; Bergenwall, B.; Hildebrand, A.; Klug, J.; Mermod, P.; Pomp, S.; Oesterlund, M.; Dangtip, S.; Tippawan, U.; Elmgren, K.; Jonsson, O.; Prokofiev, A.V.; Renberg, P.-U.; Nadel-Turonski, P.; Nilsson, L.; Olsson, N.

    2005-02-01

    The differential np scattering cross section has been measured at 96 MeV in the angular range {theta}{sub c.m.}=20 deg. -76 deg. Together with an earlier data set at the same energy, covering the angles {theta}{sub c.m.}=74 deg. -180 deg., a new data set has been formed in the angular range {theta}{sub c.m.}=20 deg. - 180 deg. This extended data set has been normalized to the experimental total np cross section, resulting in a renormalization of the earlier data of 0.7%, which is well within the reported normalization uncertainty for that experiment. A novel normalization technique has been investigated. The results on forward np scattering are in reasonable agreement with theory models and partial wave analyses and have been compared with data from the literature.

  16. Light-ion production in the interaction of 96 MeV neutrons with carbon

    SciTech Connect

    Tippawan, U.; Dangtip, S.; Pomp, S.; Blomgren, J.; Gustavsson, C.; Klug, J.; Oesterlund, M.; Nadel-Turonski, P.; Nilsson, L.; Olsson, N.; Jonsson, O.; Prokofiev, A. V.; Renberg, P.-U.; Corcalciuc, V.; Watanabe, Y.; Koning, A. J.

    2009-06-15

    Double-differential cross sections for light-ion (p, d, t, {sup 3}He, and {alpha}) production in carbon induced by 96 MeV neutrons have been measured at eight laboratory angles from 20 deg. to 160 deg. in steps of 20 deg. Experimental techniques are presented as well as procedures for data taking and data reduction. Deduced energy-differential, angle-differential, and production cross sections are reported. Experimental cross sections are compared with theoretical reaction model calculations and experimental data in the literature. The measured particle data show marked discrepancies from the results of the model calculations in spectral shape and magnitude. The measured production cross sections for protons, deuterons, tritons, {sup 3}He, and {alpha} particles support the trends suggested by data at lower energies.

  17. Light-ion production in the interaction of 96 MeV neutrons with oxygen

    SciTech Connect

    Tippawan, U.; Pomp, S.; Atac, A.; Blomgren, J.; Dangtip, S.; Hildebrand, A.; Johansson, C.; Klug, J.; Mermod, P.; Oesterlund, M.; Bergenwall, B.; Nilsson, L.; Olsson, N.; Prokofiev, A.V.; Nadel-Turonski, P.; Corcalciuc, V.; Koning, A.J.

    2006-03-15

    Double-differential cross sections are reported for light-ion (p, d, t, {sup 3}He, and {alpha}) production in oxygen induced by 96 MeV neutrons. Energy spectra are measured at eight laboratory angles from 20 degree sign to 160 degree sign in steps of 20 degree sign . Procedures for data taking and data reduction are presented. Deduced energy-differential and production cross sections are reported. Experimental cross sections are compared to theoretical reaction model calculations and experimental data at lower neutron energies in the literature. The measured proton data agree reasonably well with the results of the model calculations, whereas the agreement for the other particles is less convincing. The measured production cross sections for protons, deuterons, tritons, and {alpha} particles support the trends suggested by data at lower energies.

  18. Extraction of Weak Transition Strengths via the (He3, t) Reaction at 420MeV

    NASA Astrophysics Data System (ADS)

    Zegers, R. G. T.; Adachi, T.; Akimune, H.; Austin, Sam M.; van den Berg, A. M.; Brown, B. A.; Fujita, Y.; Fujiwara, M.; Galès, S.; Guess, C. J.; Harakeh, M. N.; Hashimoto, H.; Hatanaka, K.; Hayami, R.; Hitt, G. W.; Howard, M. E.; Itoh, M.; Kawabata, T.; Kawase, K.; Kinoshita, M.; Matsubara, M.; Nakanishi, K.; Nakayama, S.; Okumura, S.; Ohta, T.; Sakemi, Y.; Shimbara, Y.; Shimizu, Y.; Scholl, C.; Simenel, C.; Tameshige, Y.; Tamii, A.; Uchida, M.; Yamagata, T.; Yosoi, M.

    2007-11-01

    Differential cross sections for transitions of known weak strength were measured with the (He3, t) reaction at 420 MeV on targets of C12, C13, O18, Mg26, Ni58, Ni60, Zr90, Sn118, Sn120, and Pb208. Using these data, it is shown that the proportionalities between strengths and cross sections for this probe follow simple trends as a function of mass number. These trends can be used to confidently determine Gamow-Teller strength distributions in nuclei for which the proportionality cannot be calibrated via β-decay strengths. Although theoretical calculations in the distorted-wave Born approximation overestimate the data, they allow one to understand the main experimental features and to predict deviations from the simple trends observed in some of the transitions.

  19. Extraction of weak transition strengths via the (3He, t) reaction at 420 MeV.

    PubMed

    Zegers, R G T; Adachi, T; Akimune, H; Austin, Sam M; van den Berg, A M; Brown, B A; Fujita, Y; Fujiwara, M; Galès, S; Guess, C J; Harakeh, M N; Hashimoto, H; Hatanaka, K; Hayami, R; Hitt, G W; Howard, M E; Itoh, M; Kawabata, T; Kawase, K; Kinoshita, M; Matsubara, M; Nakanishi, K; Nakayama, S; Okumura, S; Ohta, T; Sakemi, Y; Shimbara, Y; Shimizu, Y; Scholl, C; Simenel, C; Tameshige, Y; Tamii, A; Uchida, M; Yamagata, T; Yosoi, M

    2007-11-16

    Differential cross sections for transitions of known weak strength were measured with the (3He, t) reaction at 420 MeV on targets of 12C, 13C, 18O, 26Mg, 58Ni, 60Ni, 90Zr, 118Sn, 120Sn, and 208Pb. Using these data, it is shown that the proportionalities between strengths and cross sections for this probe follow simple trends as a function of mass number. These trends can be used to confidently determine Gamow-Teller strength distributions in nuclei for which the proportionality cannot be calibrated via beta-decay strengths. Although theoretical calculations in the distorted-wave Born approximation overestimate the data, they allow one to understand the main experimental features and to predict deviations from the simple trends observed in some of the transitions.

  20. Calibration of imaging plates to electrons between 40 and 180 MeV.

    PubMed

    Rabhi, N; Bohacek, K; Batani, D; Boutoux, G; Ducret, J-E; Guillaume, E; Jakubowska, K; Thaury, C; Thfoin, I

    2016-05-01

    This paper presents the response calibration of Imaging Plates (IPs) for electrons in the 40-180 MeV range using laser-accelerated electrons at Laboratoire d'Optique Appliquée (LOA), Palaiseau, France. In the calibration process, the energy spectrum and charge of electron beams are measured by an independent system composed of a magnetic spectrometer and a Lanex scintillator screen used as a calibrated reference detector. It is possible to insert IPs of different types or stacks of IPs in this spectrometer in order to detect dispersed electrons simultaneously. The response values are inferred from the signal on the IPs, due to an appropriate charge calibration of the reference detector. The effect of thin layers of tungsten in front and/or behind IPs is studied in detail. GEANT4 simulations are used in order to analyze our measurements. PMID:27250413

  1. Effect of low doses of 14 MeV neutrons on polymers.

    PubMed

    Rivaton, Agnès; Arnold, Jack; Dos Santos, Morgane; Bussière, Pierre-Olivier; Taviot-Gueho, Christine

    2010-11-01

    The structural modifications of polymers irradiated with 14 MeV neutrons were studied. Two elastomers, a polypropylene-type polymer and poly(ethylene oxide) were exposed to low doses of fast neutrons in the range of 0.3-14 Gy. The radiation damages were observed at the molecular scale by infrared spectroscopy. The morphological changes were investigated by steric exclusion chromatography, insoluble fraction measurements, differential scanning calorimetry and X-ray diffraction. It was found that neutrons provoked oxidation processes accompanied by modifications in the polymer architecture, including chain scissions, crosslinking reactions and changes in the crystallinity. Moreover, the conventional antioxidants were shown to be inefficient in inhibiting the aging of the polymers. These results also suggest that the radiation damages could be used successfully for dosimetry applications using an easily implementable protocol.

  2. Behavior of nanocrystalline Xe precipitates in Al under 1 MeV electron irradiation.

    SciTech Connect

    Allen, C. W.; Birtcher, R. C.; Donnelly, S. E.; Furuya, K.; Mitsuishi, K.; Song, M.

    1999-03-10

    Crystalline nanoprecipitates of Xe have been produced by ion implantation into high purity Al at 300 K. With an off-zone axis TEM imaging technique, the nanocrystals may be clearly structure imaged against a nearly featureless background. Under the 1 MeV electron irradiation employed for the HREM observation, Xe nanocrystals exhibit a number of readily observed physical phenomena including migration within the matrix, changes in shape, faulting, melting, crystallization and coalescence. The various phenomena observed as changes in the Xe nanocrystals reflect changes of matrix cavity-surface structure. The Xe nanocrystal thus allows investigation indirectly into changes in interface morphology at the atomic level, resulting in this instance from electron irradiation damage. Such changes have heretofore been inaccessible to observation.

  3. Rat mammary-cell survival following irradiation with 14. 3-MeV neutrons

    SciTech Connect

    Mahler, P.A.; Gould, M.N.; DeLuca, P.M. Jr.; Pearson, D.W.; Clifton, K.H.

    1982-01-01

    The survival of rat mammary gland cells irradiated in situ with either single or split doses of 14.3-MeV neutrons was determined by an in vivo transplantation assay. The single-dose data are best fit to the multitarget single-hit model by the parameters D/sub 0/ = 97 cGy and n = 0.6 while the split-dose data are best fit by the parameters D/sub 0/ = 100 cGy and n = 1.2. Analysis of the combined data sets suggests that the two survival curves are not identical. Comparison of these data with previously published results following irradiation with 250-kVp x-rays is reported.

  4. Electrosphere of macroscopic 'quark nuclei': A source for diffuse MeV emissions from dark matter

    SciTech Connect

    Forbes, Michael McNeil; Lawson, Kyle; Zhitnitsky, Ariel R.

    2010-10-15

    Using a Thomas-Fermi model, we calculate the structure of the electrosphere of the quark antimatter nuggets postulated to comprise much of the dark matter. This provides a single self-consistent density profile from ultrarelativistic densities to the nonrelativistic Boltzmann regime that we use to present microscopically justified calculations of several properties of the nuggets, including their net charge, and the ratio of MeV to 511 keV emissions from electron annihilation. We find that the calculated parameters agree with previous phenomenological estimates based on the observational supposition that the nuggets are a source of several unexplained diffuse emissions from the Galaxy. As no phenomenological parameters are required to describe these observations, the calculation provides another nontrivial verification of the dark-matter proposal. The structure of the electrosphere is quite general and will also be valid at the surface of strange-quark stars, should they exist.

  5. The electrosphere of macroscopc ""nuclei"": diffuse emissions in the MeV band from dark antimatter

    SciTech Connect

    Forbes, Michael Mcneil; Lawson, Kyle; Zhitnitsky, Ariel R

    2009-01-01

    Using a Thomas-Fermi model, we calculate the structure of the electrosphere of the quark antimatter nuggets postulated to comprise much of the dark matter. This provides a single self-consistent density profile from ultra-rel ativistic densities to the non-relativistic Boltzmann regime. We use this to present a microscopically justified calculation of several properties of the nuggets, including their net charge, and the ratio of MeV to 511 keV emissions from electron annihilation. We find that the calculated parameters agree with previous phenomenological estimates based on the observational supposition that the nuggets are a source of several unexplained diffuse emissions from the galaxy. This provides another nontrivial verification of the dark matter proposal. The structure of the electrosphere is quite general and will also be valid at the surface of strange-quark stars, should they exist.

  6. New source of MeV negative ion and neutral atom beams

    NASA Astrophysics Data System (ADS)

    Ter-Avetisyan, S.; Braenzel, J.; Schnürer, M.; Prasad, R.; Borghesi, M.; Jequier, S.; Tikhonchuk, V.

    2016-02-01

    The scenario of "electron-capture and -loss" was recently proposed for the formation of negative ion and neutral atom beams with MeV kinetic energies. However, it does not explain why the formation of negative ions in a liquid spray is much more efficient than with an isolated atom. The role of atomic excited states in the charge-exchange processes is considered, and it is shown that it cannot account for the observed phenomena. The processes are more complex than the single electron-capture and -loss approach. It is suggested that the shell effects in the electronic structure of the projectile ion and/or target atoms may influence the capture/loss probabilities.

  7. Spectroscopy in the 10 keV to 10 MeV range

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.

    1981-01-01

    Spectral lines in the 10 keV to 1 MeV range carry information of fundamental importance on many astronomical objects. Since the lines are directly related to specific physical processes this information is model independent and gives the physical conditions in the objects. At the sensitivities achieved to date, approximately 0.0001 to 0.001 phsq cm. sec for steady sources and approximately 0.01 to 1 ph/sq cm sec for transient sources, lines were detected from the galactic center, gamma-ray bursts and transients, X-ray pulsators, the Crab pulsar and solar flares. Future instruments with a factor of approximately 100 sensitivity improvement will allow detailed spectroscopic study of these classes of objects as well as supernova remnants, active galaxies and the interstellar medium. This sensitivity improvement can be obtained through the use of detector technology already proven in balloon and satellite instruments.

  8. Results of LEBT/MEBT reconfiguration at BNL 200 MeV LINAC

    SciTech Connect

    Raparia,D.; Alessi, J.; Briscoe, B.; Fite, J.; Gould, O.; Kponou, A.; Lo Destro, V.; Okamura, M.; Ritter, J.

    2009-05-04

    The low energy (35 keV) and medium energy (750 keV) transport lines for both polarized and unpolarized H{sup -} have been reconfigured to reduce the beam emittance and beam losses out of the 200 MeV Linac. The medium energy line in the original layout was 7 m long, and had ten quadrupoles, two beam choppers, and three bunchers. The bunchers were necessary to keep the beam bunched at the entrance of the Linac. About 35% beam loss occurred, and the emittance growth was several fold. In the new layout, the 750 keV line is only 0.7 m long, with three quads and one buncher. We will present the experimental result of the upgrade.

  9. Development of a lithium liquid metal ion source for MeV ion beam analysis

    SciTech Connect

    Read, P.M.; Maskrey, J.T.; Alton, G.D.

    1988-01-01

    Lithium liquid metal ion sources are an attractive complement to the existing gaseous ion sources that are extensively used for ion beam analysis. This is due in part to the high brightness of the liquid metal ion source and in part to the availability of a lithium ion beam. High brightness is of particular importance to MeV ion microprobes which are now approaching current density limitations on targets determined by the ion source. The availability of a lithium beam provides increased capabilities for hydrogen profiling and high resolution Rutherford backscattering spectrometry. This paper describes the design and performance of a lithium liquid metal ion source suitable for use on a 5MV Laddertron accelerator. Operational experience with the source and some of its uses for ion beam analysis are discussed. 8 refs., 2 figs.

  10. Radiation effects induced in pin photodiodes by 40- and 85-MeV protons

    NASA Technical Reports Server (NTRS)

    Becher, J.; Kernell, R. L.; Reft, C. S.

    1985-01-01

    PIN photodiodes were bombarded with 40- and 85-MeV protons to a fluence of 1.5 x 10 to the 11th power p/sq cm, and the resulting change in spectral response in the near infrared was determined. The photocurrent, dark current and pulse amplitude were measured as a function of proton fluence. Changes in these three measured properties are discussed in terms of changes in the diode's spectral response, minority carrier diffusion length and depletion width. A simple model of induced radiation effects is presented which is in good agreement with the experimental results. The model assumes that incident protons produce charged defects within the depletion region simulating donor type impurities.

  11. Results of hybrid photodiode irradiation by 200 MeV protons

    SciTech Connect

    Baumbaugh A. et al.

    2001-12-03

    Hybrid Photodiodes (HPD, [1]) will be used as the photodetector for the Compact Muon Solenoid (CMS) Hadron Calorimeter (HCAL) readout [2]. The HPDs are required to operate in a high radiation environment, where the HCAL detector will receive a total ionizing dose of about 330 rads and a fluence of 4 x 10{sup 11} n/cm{sup 2} over a 10 year running period [3]. Effects of HPD irradiation by low energy neutrons were studied and reported previously [1]. In these studies, high energy protons are used to study possible effects of single event burnout [4], since high energy protons are more likely to induce large energy transfer within the HPD silicon. The HPDs were irradiated by 200 MeV protons at the Indiana University Cyclotron Facility [IUCF, 5]. The results of the study are presented.

  12. Low-energy theorems for nucleon-nucleon scattering at Mπ=450 MeV

    NASA Astrophysics Data System (ADS)

    Baru, V.; Epelbaum, E.; Filin, A. A.

    2016-07-01

    We apply the low-energy theorems to analyze the recent lattice QCD results for the two-nucleon system at a pion mass of Mπ≃450 MeV obtained by the NPLQCD Collaboration. We find that the binding energies of the deuteron and dineutron are inconsistent with the low-energy behavior of the corresponding phase shifts within the quoted uncertainties and vice versa. Using the binding energies of the deuteron and dineutron as input, we employ the low-energy theorems to predict the phase shifts and extract the scattering length and the effective range in the S31 and S10 channels. Our results for these quantities are consistent with those obtained by the NPLQCD Collaboration from effective field theory analyses but are in conflict with their determination based on the effective-range approximation.

  13. Rat mammary cell survival following irradiation with 14. 3-MeV neutrons

    SciTech Connect

    Mahler, P.A.; Gould, M.N.; DeLuca, P.M. Jr.; Pearson, D.W.; Clifton, K.H.

    1982-08-01

    The survival of rat mammary gland cells irradiated in situ with either single or split doses of 14.3-MeV neutrons was determined by an in vivo transplantation assay. The single-dose data are best fit to the multitarget single-hit model by the parameters D/sub o/ = 97 cGy and n = 0.6 while the split-dose data are best fit by the parameters D/sub o/ = 100 cGy and n = 1.2.Analysis of the combined data sets suggests that the two survival curves are not identical. Comparison of these data with previously published results following irradiation with 250-kVp X rays is reported.

  14. Radiation pressure acceleration of protons to 93 MeV with circularly polarized petawatt laser pulses

    NASA Astrophysics Data System (ADS)

    Kim, I. Jong; Pae, Ki Hong; Choi, Il Woo; Lee, Chang-Lyoul; Kim, Hyung Taek; Singhal, Himanshu; Sung, Jae Hee; Lee, Seong Ku; Lee, Hwang Woon; Nickles, Peter V.; Jeong, Tae Moon; Kim, Chul Min; Nam, Chang Hee

    2016-07-01

    The radiation pressure acceleration (RPA) of charged particles has been a challenging task in laser-driven proton/ion acceleration due to its stringent requirements in laser and target conditions. The realization of radiation-pressure-driven proton acceleration requires irradiating ultrathin targets with an ultrahigh contrast and ultraintense laser pulses. We report the generation of 93-MeV proton beams achieved by applying 800-nm 30-fs circularly polarized laser pulses with an intensity of 6.1 × 10 20 W / cm 2 to 15-nm-thick polymer targets. The radiation pressure acceleration was confirmed from the obtained optimal target thickness, quadratic energy scaling, polarization dependence, and three-dimensional particle-in-cell simulations. We expect this clear demonstration of RPA to facilitate the realization of laser-driven proton/ion sources delivering energetic and short-pulse particle beams for novel applications.

  15. The EB10 10 MeV, 30 kW electron irradiation facility

    NASA Astrophysics Data System (ADS)

    Karlsson, Mikael

    An irradiation plant including a 10 MeV, 30 kW electron accelerator is described. The accelerator is a four stage linac of standing wave type. Using a 90 degrees bending magnet for energy definition it irradiates boxes on a conveyor from below. The system design emphasizes the necessity for documentation of absorbed dose for each irradiated box by continuous monitoring and recording of the beam process parameters. This makes the system well suitable for irradiation sterilization. A magnet at the exit window corrects for the divergent field introduced by the scanning magnet, giving vertical electrons over the full scanning width. This feature provides more uniform irradiation and it also increases the efficiency of the unit by almost 20 %.

  16. Transmission secondary ion mass spectrometry using 5 MeV C60+ ions

    NASA Astrophysics Data System (ADS)

    Nakajima, K.; Nagano, K.; Suzuki, M.; Narumi, K.; Saitoh, Y.; Hirata, K.; Kimura, K.

    2014-03-01

    In the secondary ion mass spectrometry (SIMS), use of cluster ions has an advantage of producing a high sensitivity of intact large molecular ions over monatomic ions. This paper presents further yield enhancement of the intact biomolecular ions by measuring the secondary ions emitted in the forward direction. Phenylalanine amino acid films deposited on self-supporting thin Si3N4 films were bombarded with 5 MeV C60 ions. Secondary ions emitted in the forward and backward directions were measured. The yield of intact phenylalanine molecular ions emitted in the forward direction is significantly enhanced compared to the backward direction while fragment ions are suppressed. This suggests a large potential of using transmission cluster ion SIMS for the analysis of biological materials.

  17. Activation cross sections of proton induced nuclear reactions on gold up to 65MeV.

    PubMed

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A

    2016-07-01

    Activation cross sections of proton induced reactions on gold for production of (197m,197g,195m,195g, 193m,193g,192)Hg, (196m,196g(cum),195g(cum),194,191(cum))Au, (191(cum))Pt and (192)Ir were measured up to 65MeV proton energy, some of them for the first time. The new data are in acceptably good agreement with the recently published earlier experimental data in the overlapping energy region. The experimental data are compared with the predictions of the TALYS 1.6 (results in TENDL-2015 on-line library) and EMPIRE 3.2 code. PMID:27156194

  18. Diagnostic experiments at a 3 MeV test stand at Rutherford Appleton Laboratory (United Kingdom)

    SciTech Connect

    Gabor, C.; Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P.; Lee, D. A.; Pozimski, J. K.

    2010-02-15

    A front end is currently under construction consisting of a H{sup -} Penning ion source (65 keV, 60 mA), low energy beam transport (LEBT), and radio frequency quadrupole (3 MeV output energy) with a medium energy beam transport suitable for high power proton applications. Diagnostics can be divided either in destructive techniques such as beam profile monitor, pepperpot, slit-slit emittance scanner (preferably used during commissioning) or nondestructive, permanently installed devices such as photodetachment-based techniques. Another way to determine beam distributions is a scintillator with charge-coupled device camera. First experiments have been performed to control the beam injection into the LEBT. The influence of beam parameters such as particle energy and space-charge compensation on the two-dimensional distribution and profiles will be presented.

  19. Charge neutralized low energy beam transport at Brookhaven 200 MeV linac

    NASA Astrophysics Data System (ADS)

    Raparia, D.; Alessi, J.; Atoian, G.; Zelenski, A.

    2016-02-01

    The H- magnetron source provides about 100 mA H- beam to be match into the radio-frequency quadrupole accelerator. As H- beam traverses through low energy transport, it ionizes the residual gas and electrons are repelled and positive ions are trapped in the beam, due to negative potential of the beam, providing charge neutralization for the H- beam. The neutralization time for the critical density depends upon the background gas and its pressure. Critical density for xenon gas at 35 keV is about 43 times smaller than that of hydrogen and stripping cross section is only 5 times than that of hydrogen gas. We are using xenon gas to reduce neutralization time and to improve transmission through the 200 MeV linac. We are also using pulse nitrogen gas to improve transmission and stability of polarized H- beam from optically pumped polarized ion source.

  20. Acceleration of Solar Wind Ions to 1 Mev by Electromagnetic Moguls in the Foreshock

    NASA Astrophysics Data System (ADS)

    Stasiewicz, K.; Strumik, M.; Markidis, S.; Eliasson, B.; Yamauchi, M.

    2013-05-01

    We present measurements from the ESA/NASA Cluster mission that show in situ acceleration of ions to energies of 1 MeV outside the bow shock. The observed heating can be associated with the presence of electromagnetic structures with strong spatial gradients (divergence) of the electric field that lead to ion gyro-phase breaking and to the onset of chaos in ion trajectories. It results in rapid, stochastic acceleration of ions in the direction perpendicular to the ambient magnetic field. The electric potential of the structures can be compared to a field of moguls on a ski slope, capable of accelerating and ejecting the fast running skiers out of piste. This mechanism may represent the universal, basic mechanism for perpendicular acceleration and heating of ions in the magnetosphere, the solar corona and in astrophysical plasmas.