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Sample records for 123-group neutron cross-section

  1. [Fast neutron cross section measurements

    International Nuclear Information System (INIS)

    This paper discusses the following topics: 14 MeV pulsed neutron facility; detection and measurement system; 238U capture cross sections at 23 and 964 keV using photon neutron sources; capture cross sections of Au-197 at 23 and 964 keV; and yttrium nuclear cross section measurement

  2. [Fast neutron cross section measurements

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  3. Measurements of neutron capture cross sections

    International Nuclear Information System (INIS)

    A review of measurement techniques for the neutron capture cross sections is presented. Sell transmission method, activation method, and prompt gamma-ray detection method are described using examples of capture cross section measurements. The capture cross section of 238U measured by three different prompt gamma-ray detection methods (large liquid scintillator, Moxon-Rae detector, and pulse height weighting method) are compared and their discrepancies are resolved. A method how to derive the covariance is described. (author)

  4. Covariance Evaluation Methodology for Neutron Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  5. Neutron cross section of methane hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Kiyanagi, Y.; Date, S.; Horikawa, T.; Takamine, J.; Iwasa, H.; Kamiyama, T. [Graduate School of Eng., Hokkaido Univ., Sapporo (Japan); Uchida, T.; Ebinuma, T.; Narrita, H. [National Inst. of Advanced Industrial Science, Tsukisamu, Sapporo (Japan); Bennington, S.M. [ISIS Dept., Rutherford Appleton, Chilton, Didcot, Oxon (United Kingdom)

    2004-03-01

    To estimate the neutronic characteristics of methane hydrate and also to synthesize cross section data for simulation we need neutron scattering data ranging wide energy and momentum region. We performed inelastic neutron scattering experiments to get information about the neutron cross section on methane hydrate. It was found that at high momentum transfer region rotational mode as well as vibration mode showed recoil like behavior. On the other hand, at low momentum region, as well known, free rotation like energy levels were observed. The energy level of ice in methane hydrate was very similar to normal ice. The results suggest that the rough expression of the cross section of the methane hydrate is presented by linear combination of the methane and ice. (orig.)

  6. Neutron cross sections of importance to astrophysics

    International Nuclear Information System (INIS)

    Neutron reactions of importance to the various stellar burning cycles are discussed. The role of isomeric states in the branched s-process is considered for particular cases. Neutron cross section needs for the 187Re-187Os, 87Rb-87Sr clocks for nuclear cosmochronology are discussed. Other reactions of interest to astrophysical processes are presented. 35 references

  7. Neutron capture cross sections from Surrogate measurements

    OpenAIRE

    Scielzo N.D.; Dietrich F.S.; Escher J.E.

    2010-01-01

    The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ) cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.

  8. Neutron capture cross sections from Surrogate measurements

    Directory of Open Access Journals (Sweden)

    Scielzo N.D.

    2010-03-01

    Full Text Available The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.

  9. Evaluation methods for neutron cross section standards

    International Nuclear Information System (INIS)

    Methods used to evaluate the neutron cross section standards are reviewed and their relative merits, assessed. These include phase-shift analysis, R-matrix fit, and a number of other methods by Poenitz, Bhat, Kon'shin and the Bayesian or generalized least-squares procedures. The problems involved in adopting these methods for future cross section standards evaluations are considered, and the prospects for their use, discussed. 115 references, 5 figures, 3 tables

  10. Neutron capture cross section of Am241

    Science.gov (United States)

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

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  11. Neutron capture cross section measurement techniques

    International Nuclear Information System (INIS)

    A review of currently-used techniques to measure neutron capture cross sections is presented. Measurements involving use of total absorption and Moxon-Rae detectors are based on low-resolution detection of the prompt γ-ray cascades following neutron captures. In certain energy ranges activation methods are convenient and useful. High resolution γ-ray measurements with germanium detectors can give information on the parameters of resonance capture states. The use of these techniques is described. (U.S.)

  12. Atlas of neutron capture cross sections

    International Nuclear Information System (INIS)

    This report describes neutron capture cross sections in the range 10-5 eV - 20 MeV as evaluated and compiled in recent activation libraries. The selected subset comprise the (n,γ) cross sections for a total of 739 targets for the elements H (Z = 1, Z = 1) to Cm (Z = 96, A = 238) totaling 972 reactions. Plots of the point-wise data are shown and comparisons are made with the available experimental values at thermal energy, 30 keV and 14.5 MeV. 10 refs, 7 tabs

  13. Neutron cross section standards and instrumentation

    Science.gov (United States)

    1992-09-01

    This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the second year of a three-year interagency agreement. This program includes a broad range of data measurements and evaluations. An emphasis has been focused on the (sup 10)B cross sections where serious discrepancies in the nuclear data base remain. In particular, there are important problems with the interpretation of the helium gas production associated with diagnostic measurements of interest in nuclear technology. The enhanced use of this isotope for medical treatment is also of significance. New measurements of neutron reaction cross sections for (sup 10)B are in progress in collaboration with scientists at the Oak Ridge National Laboratory. New experiments are in progress on the important dosimetry standards (sup 237)Np(n,f) and (sup 239)Pu(n,f) below 1 MeV neutron energy. In addition, new measurements of charged-particle production in basic biological elements for medical applications are underway. Further measurements are planned or in progress in collaborations which include fission fragment energy and angular distributions, and neutron energy spectra and angular distributions from neutron-induced fission. Also measurements of angular distributions of neutrons from scattering on protons, and determinations of capture cross section of gold are planned for a later time. Data evaluation will shift to include a unified international effort to motivate new measurements and evaluations. In response to the requests of the measurement community, NIST is beginning the formation of a national depository for fissionable isotope mass standards. This action will preserve for future measurements the valuable and irreplaceable critical samples whose masses and composition have been carefully determined and documented over the past 30 years of the nuclear program.

  14. Measurements of neutron spallation cross section. 2

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Imamura, M.; Nakao, N.; Shibata, S.; Uwamino, Y.; Nakanishi, N.; Tanaka, Su.

    1997-03-01

    Neutron spallation cross section of {sup 59}Co(n,xn){sup 60-x}Co, {sup nat}Cu(n,sp){sup 56}Mn, {sup nat}Cu(n,sp){sup 58}Co, {sup nat}Cu(n,xn){sup 60}Cu, {sup nat}Cu(n,xn){sup 61}Cu and {sup nat}Cu(n,sp){sup 65}Ni was measured in the quasi-monoenergetic p-Li neutron fields in the energy range above 40 MeV which have been established at three AVF cyclotron facilities of (1) INS of Univ. of Tokyo, (2) TIARA of JAERI and (3) RIKEN. Our experimental data were compared with the ENDF/B-VI high energy file data by Fukahori and the calculated cross section data by Odano. (author)

  15. Total cross sections for neutron-nucleus scattering

    OpenAIRE

    Suryanarayana, S. V.; H. Naik; Ganesan, S; Kailas, S; Choudhury, R. K.; Kim, Guinyum

    2010-01-01

    Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross section...

  16. Neutron removal cross section as a measure of neutron skin

    OpenAIRE

    D. Q. Fang; Y. G. Ma; Cai, X. Z.(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 201800, Shanghai, China); Tian, W.D.; Wang, H. W.

    2010-01-01

    We study the relation between neutron removal cross section ($\\sigma_{-N}$) and neutron skin thickness for finite neutron rich nuclei using the statistical abrasion ablation (SAA) model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between $\\sigma_{-N}$ and the neutron skin thickness for neutron rich nuclei. Further analysis suggests that the relative increa...

  17. Neutron capture cross section of $^{93}$Zr

    CERN Multimedia

    We propose to measure the neutron capture cross section of the radioactive isotope $^{93}$Zr. This project aims at the substantial improvement of existing results for applications in nuclear astrophysics and emerging nuclear technologies. In particular, the superior quality of the data that can be obtained at n_TOF will allow on one side a better characterization of s-process nucleosynthesis and on the other side a more accurate material balance in systems for transmutation of nuclear waste, given that this radioactive isotope is widely present in fission products.

  18. ISSUES IN NEUTRON CROSS SECTION COVARIANCES

    Energy Technology Data Exchange (ETDEWEB)

    Mattoon, C.M.; Oblozinsky,P.

    2010-04-30

    We review neutron cross section covariances in both the resonance and fast neutron regions with the goal to identify existing issues in evaluation methods and their impact on covariances. We also outline ideas for suitable covariance quality assurance procedures.We show that the topic of covariance data remains controversial, the evaluation methodologies are not fully established and covariances produced by different approaches have unacceptable spread. The main controversy is in very low uncertainties generated by rigorous evaluation methods and much larger uncertainties based on simple estimates from experimental data. Since the evaluators tend to trust the former, while the users tend to trust the latter, this controversy has considerable practical implications. Dedicated effort is needed to arrive at covariance evaluation methods that would resolve this issue and produce results accepted internationally both by evaluators and users.

  19. Measurement of thermal neutron capture cross section

    CERN Document Server

    Huang Xiao Long; LuHanLin; Yu Wei Xiang; Zhao Wen Rong

    2001-01-01

    The thermal neutron capture cross sections of sup 7 sup 1 Ga(n, gamma) sup 7 sup 2 Ga, sup 9 sup 4 Zr(n, gamma) sup 9 sup 5 Zr and sup 1 sup 9 sup 1 Ir(n, gamma) sup 1 sup 9 sup 2 Ir sup m sup 1 sup + sup g sup , sup m sup 2 reactions were measured by using activation method and compared with other measured data. Meanwhile the half-life of sup 7 sup 2 Ga was also measured. The samples were irradiated with the neutron in the thermal column of heavy water reactor of China Institute of Atomic Energy. The activities of the reaction products were measured by well-calibrated Ge(Li) detector

  20. [Fast neutron cross section measurements]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  1. Neutron inelastic cross section measurements for 24Mg

    OpenAIRE

    OLACEL A.; Borcea, C.; DESSAGNE Philippe; Kerveno, M.; NEGRET A.; PLOMPEN Arjan

    2014-01-01

    The gamma production cross sections from the neutron inelastic scattering on 24Mg were measured for neutron energies up to 18 MeV at GELINA (Geel Linear Accelerator), the neutron source operated by EC-JRC-IRMM, Belgium. The level cross section and the total inelastic cross section were determined. We used the GAINS (Gamma Array for Inelastic Neutron Scattering) spectrometer with 7 large volume HPGe detectors placed at 110◦ and 150◦ with respect to the beam direction. The neutron flux was dete...

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

    Science.gov (United States)

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

    2016-03-01

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

  3. Studies of 54,56Fe Neutron Scattering Cross Sections

    Directory of Open Access Journals (Sweden)

    Hicks S. F.

    2015-01-01

    Full Text Available Elastic and inelastic neutron scattering differential cross sections and γ-ray production cross sections have been measured on 54,56Fe at several incident energies in the fast neutron region between 1.5 and 4.7 MeV. All measurements were completed at the University of Kentucky Accelerator Laboratory (UKAL using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. The facilities at UKAL allow the investigation of both elastic and inelastic scattering with nearly mono-energetic incident neutrons. Time-of-flight techniques were used to detect the scattered neutrons for the differential cross section measurements. The measured cross sections are important for fission reactor applications and also for testing global model calculations such as those found at ENDF, since describing both the elastic and inelastic scattering is important for determining the direct and compound components of the scattering mechanism. The γ-ray production cross sections are used to determine cross sections to unresolved levels in the neutron scattering experiments. Results from our measurements and comparisons to model calculations are presented.

  4. Modelling of reaction cross sections and prompt neutron emission

    Science.gov (United States)

    Hambsch, F.-J.; Tudora, A.; Oberstedt, S.

    2010-10-01

    Accurate nuclear data concerning reaction cross sections and the emission of prompt fission neutrons (i.e. multiplicity and spectra) as well as other fission fragment data are of great importance for reactor physics design, especially for the new Generation IV nuclear energy systems. During the past years for several actinides (238U(n, f) and 237Np(n, f)) both the reaction cross sections and prompt neutron multiplicities and spectra have been calculated within the frame of the EFNUDAT project.

  5. Modelling of reaction cross sections and prompt neutron emission

    OpenAIRE

    Oberstedt S.; Tudora A.; Hambsch F.-J.

    2010-01-01

    Accurate nuclear data concerning reaction cross sections and the emission of prompt fission neutrons (i.e. multiplicity and spectra) as well as other fission fragment data are of great importance for reactor physics design, especially for the new Generation IV nuclear energy systems. During the past years for several actinides (238U(n, f) and 237Np(n, f)) both the reaction cross sections and prompt neutron multiplicities and spectra have been calculated within the frame of the EFNUDAT project.

  6. Neutron capture cross sections of 151,153Eu

    International Nuclear Information System (INIS)

    The neutron capture cross section of 151,153Eu nuclei was measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos Neutron Science Center (LANSCE). Neutrons were produced at the Lujan Neutron Scattering Center and their energies were determined by the time-of-flight technique. The relative yield versus neutron incident energy from 0.1 eV to 2.0 keV for both 151Eu(n,) and 153Eu(n,) reactions was derived from events gated on the total energy and multiplicity measured by the DANCE array. The absolute cross section was determined by scaling the relative yield to the measured cross sections of well-known resonances. The shape of the yield curve agrees well with previous measurements in the resonance region for both 151Eu and 153Eu capture cross sections. New data are reported for neutron incident energies between 100 eV and 2.0 keV. The trend of data in the 0.3 keV to 2.0 keV region of neutron incident energy is consistent with the ENDF/BVI and the measurements of Macklin and Young. Crucial skills, acquired from these measurements in the early implementation of DANCE, are important to plan future experiments, which will yield results up to a few hundred keV neutron incident energy

  7. Theory of neutron resonance cross sections for safety applications

    International Nuclear Information System (INIS)

    Neutron resonances exert a strong influence on the behaviour of nuclear reactors, especially on their response to the temperature changes accompanying power excursions, and also on the efficiency of shielding materials. The relevant theory of neutron resonance cross sections including the practically important approximations is reviewed, both for the resolved and the unresolved resonance region. Numerical techniques for Doppler broadening of resonances are presented, and the construction of group constants and especially of self-shielding factors for neutronics calculations is outlined. (orig.)

  8. Measurement of the 242Pu neutron capture cross section

    Science.gov (United States)

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

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  9. Modelling of reaction cross sections and prompt neutron emission

    Directory of Open Access Journals (Sweden)

    Oberstedt S.

    2010-10-01

    Full Text Available Accurate nuclear data concerning reaction cross sections and the emission of prompt fission neutrons (i.e. multiplicity and spectra as well as other fission fragment data are of great importance for reactor physics design, especially for the new Generation IV nuclear energy systems. During the past years for several actinides (238U(n, f and 237Np(n, f both the reaction cross sections and prompt neutron multiplicities and spectra have been calculated within the frame of the EFNUDAT project.

  10. Phenomenological dirac optical potential for neutron cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Shin-ichi; Kitsuki, Hirohiko; Shigyo, Nobuhiro; Ishibashi, Kenji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1997-03-01

    Because of limitation on neutron-incident data, it is difficult to obtain global optical model potential for neutrons. In contrast, there are some global optical model potentials for proton in detail. It is interesting to convert the proton-incident global optical potentials into neutron-incident ones. In this study we introduce (N-Z)/A dependent symmetry potential terms into the global proton-incident optical potentials, and then obtain neutron-incident ones. The neutron potentials reproduce total cross sections in an acceptable degree. However, a comparison with potentials proposed by other authors brings about a confused situation in the sign of the symmetry terms. (author)

  11. Titanium-I: fast neutron cross section measurements

    International Nuclear Information System (INIS)

    Energy averaged total neutron cross sections are measured from approximately 1.0 to 4.5 MeV with few percent statistical accuracies. Differential elastic neutron scattering angular distributions are measured from 1.5 to 4.0 MeV at incident neutron energy intervals of less than or equal to 0.2 MeV. Differential cross sections for the inelastic neutron excitation of ''states'' at 158 +- 26, 891 +- 8, 984 +- 15, 1428 +- 39, 1541 +- 30, 1670 +- 80, 2007 +- 8, 2304 +- 22, 2424 +- 16, and 2615 +- 10 keV are measured for incident neutron energies from 1.5 to 4.0 MeV. Additional ''states'' are observed at approximately 2845 and 3009 keV. An energy-averaged optical-statistical model is deduced from the measured values and the implications of its use in the context of the strong fluctuating structure is discussed

  12. Measured and evaluated neutron cross sections of elemental bismuth

    International Nuclear Information System (INIS)

    Neutron total cross sections of elemental bismuth are measured with broad resolution from 1.2 to 4.5 MeV to accuracies of approx. = 1%. Neutron-differential-elastic-scattering cross sections of bismuth are measured from 1.5 to 4.0 MeV at incident neutron energy intervals of approx.< 0.2 MeV over the scattered-neutron angular range approx. = 20 to 160 deg. Differential neutron cross sections for the excitation of observed states in bismuth at 895 +- 12, 1606 +- 14, 2590 +- 15, 2762 +- 29, 3022 +- 21, and 3144 +- 15 keV are determined at incident neutron energies up to 4.0 MeV. An optical-statistical model is deduced from the measured values. This model, the present experimental results, and information available elsewhere in the literature are used to construct a comprehensive evaluated nuclear data file for elemental bismuth in the ENDF format. The evaluated file is particularly suited to the neutronic needs of the fusion-fission hybrid designer. 87 references, 10 figures, 6 tables

  13. Neutron Capture Cross Sections of 236U and 234U

    Science.gov (United States)

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; Kronenberg, A.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2006-03-01

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-π solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  14. Nuclear Astrophysics and Neutron Cross Section Measurements Using the ORELA

    International Nuclear Information System (INIS)

    This is the final report for a research program which has been continuously supported by the AEC, ERDA, or USDOE since 1973. The neutron total and capture cross sections for n + 88Sr have been measured over the neutron energy range 100 eV to 1 MeV. The report briefly summaries our results and the importance of this work for nucleosynthesis and the optical model

  15. Measurements of neutron cross sections of radioactive waste nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi

    1998-01-01

    Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)

  16. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    Science.gov (United States)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  17. Neutron cross section standards and instrumentation: Annual report

    International Nuclear Information System (INIS)

    This annual report from the National Bureau of Standards contains a summary of the results of the Neutron Cross Section Standards and Instrumentation Program. The technical measurements for the past year are given along with the proposed program and budget needs for the next three years. The neutron standards measurements have concentrated on the most important 235U(n,f) cross section in the thermal to 20 MeV energy range along with the development of neutron detectors required for these measurements. The NBS measurements have made a significant contribution to the improvement in the understanding of this reaction. Measurements were performed with numerous neutron detectors at overlapping energies and at different neutron sources in order to reduce the systematic errors to achieve the required accuracy in this important neutron standard. Significant progress was also made in the development of a detector to utilize the 3He(n,p) reaction as a standard in the eV to MeV energy region. Improvements in data acquisition systems as well as additional studies of advanced neutron sources were accomplished. Contacts with private industry were maintained and coordination of the neutron standards evaluation was continued. The report also includes biographical listings of the research staff along with copies of a few of our recent publications. 13 figs., 1 tab

  18. Nuclear fission and neutron-induced fission cross-sections

    CERN Document Server

    James, G D; Michaudon, A; Michaudon, A; Cierjacks, S W; Chrien, R E

    2013-01-01

    Nuclear Fission and Neutron-Induced Fission Cross-Sections is the first volume in a series on Neutron Physics and Nuclear Data in Science and Technology. This volume serves the purpose of providing a thorough description of the many facets of neutron physics in different fields of nuclear applications. This book also attempts to bridge the communication gap between experts involved in the experimental and theoretical studies of nuclear properties and those involved in the technological applications of nuclear data. This publication will be invaluable to those interested in studying nuclear fis

  19. Evaluation and calculation of neutron transactinide cross-sections

    International Nuclear Information System (INIS)

    This paper reviews the state of the art of nuclear theory and its application to the evaluation and calculation of neutron reaction cross sections of transactinium isotopes. In particular, the paper describes the current evaluation of the total files of neutron reaction data for 240Pu and 241Pu in the energy range between 10-5 eV and 15 MeV based on a thorough analysis of available experimental data and on the use of modern theoretical concepts, and the work in progress on the evaluation of the total neutron reaction data file for 242Pu and 241Am. (author)

  20. Neutron Capture Cross Sections for the Weak s Process

    CERN Document Server

    Heil, M; Kaeppeler, F; Gallino, R; Pignatari, M; Uberseder, E

    2009-01-01

    In past decades a lot of progress has been made towards understanding the main s-process component that takes place in thermally pulsing Asymptotic Giant Branch (AGB) stars. During this process about half of the heavy elements, mainly between 90=8Msolar) and is much less understood. A better characterization of the weak s component would help disentangle the various contributions to element production in this region. For this purpose, a series of measurements of neutron-capture cross sections have been performed on medium-mass nuclei at the 3.7-MV Van de Graaff accelerator at FZK using the activation method. Also, neutron captures on abundant light elements with A<56 play an important role for s-process nucleosynthesis, since they act as neutron poisons and affect the stellar neutron balance. New results are presented for the (n,g) cross sections of 41K and 45Sc, and revisions are reported for a number of cross sections based on improved spectroscopic information.

  1. Neutron cross section calculations for fission-product nuclei

    International Nuclear Information System (INIS)

    To satisfy nuclear data requirements for fission-product nuclei, Hauser-Feshbach statistical calculations with preequilibrium corrections for neutron-induced reactions on isotopes of Se, Kr, Sr, Zr, Mo, Sn, Xe, and Ba between 0.001 and 20 MeV. Spherical neutron optical parameters were determined by simultaneous fits to resonance data and total cross sections. Isospin coefficients appearing in the optical potentials were determined through analysis of the behavior of s- and p-wave strengths as a function of mass for a given Z. Gamma-ray strength functions, determined through fits to stable-isotope capture data, were used in the calculation of capture cross sections and gamma-ray competition to particle emission. The resulting (n,γ), (n,n'), (n,2n), and (n,3n) cross sections, the secondary neutron emission spectra, and angular distributions calculated for 19 fission products will be averaged to provide a resulting ENDF-type fission-product neutronics file. 11 references

  2. Neutron capture cross section on Lu isotopes at DANCE

    International Nuclear Information System (INIS)

    The DANCE (Detector for Advanced Neutron Capture Experiments) array at the LANSCE spallation neutron source in Los Alamos has been used to measure neutron capture cross sections for 175Lu and 176Lu with neutron energies from thermal up to 100 keV. Both isotopes are of current interest for the s-process nucleosynthesis. 175Lu is an important waiting-point in the s-process and 176Lu is a sensitive s-process thermometer. Three targets were used to perform these measurements. One was a natural Lu foil of 31 mg/cm2 and the other two were isotopically enriched targets of 175Lu (99.8%, ∼1 mg/cm2 electro-deposited on Ti) and 176Lu (99.9%, ∼1 mg/cm2 mass separator deposited on aluminized mylar). The data analysis is in progress. Preliminary cross sections have been obtained by normalizing the data to the known thermal cross section. A comparison of these data with recent experimental data of K. Wisshak et al. and the evaluated data of ENDF B-VII will be presented.

  3. Resonance averaged channel radiative neutron capture cross sections

    International Nuclear Information System (INIS)

    In order to apply Lane amd Lynn's channel capture model in calculations with a realistic optical model potential, we have derived an approximate wave function for the entrance channel in the neutron-nucleus reaction, based on the intermediate interaction model. It is valid in the exterior region as well as the region near the nuclear surface, ans is expressed in terms of the wave function and reactance matrix of the optical model and of the near-resonance parameters. With this formalism the averaged channel radiative neutron capture cross section in the resonance region is written as the sum of three terms. The first two terms correspond to contribution of the optical model real and imaginary parts respectively, and together can be regarded as the radiative capture of the shape elastic wave. The third term is a fluctuation term, corresponding to the radiative capture of the compound elastic wave in the exterior region. On applying this theory in the resonance region, we obtain an expression for the average valence radiative width similar to that of Lane and Mughabghab. We have investigated the magnitude and energy dependence of the three terms as a function of the neutron incident energy. Calculated results for 98Mo and 55Mn show that the averaged channel radiative capture cross section in the giant resonance region of the neutron strength function may account for a considerable fraction of the total (n, γ) cross section; at lower neutron energies a large part of this channel capture arises from the fluctuation term. We have also calculated the partial capture cross section in 98Mo and 55Mn at 2.4 keV and 24 keV, respectively, and compared the 98Mo results with the experimental data. (orig.)

  4. Neutron cross section standards and instrumentation. Annual report

    International Nuclear Information System (INIS)

    The objective of this interagency program is to provide accurate neutron interaction measurements for the US Department of Energy nuclear programs which include waste disposal, fusion, safeguards, defense, fission, and personnel protection. These measurements are also useful to other energy programs which indirectly use the unique properties of the neutron for diagnostic and analytical purposes. The work includes the measurement of reference cross sections and related neutron data employing unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; the preservation of standard reference deposits and the development of improved neutron detectors and measurement methods. A related and essential element of the program is critical evaluation of neutron interaction data including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology. This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the third year of this three-year interagency agreement. The proposed program and required budget for the following three years are also presented. The program continues the shifts in priority instituted in order to broaden the program base

  5. Neutron cross section standards and instrumentation. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Wasson, O.A.

    1993-07-01

    The objective of this interagency program is to provide accurate neutron interaction measurements for the US Department of Energy nuclear programs which include waste disposal, fusion, safeguards, defense, fission, and personnel protection. These measurements are also useful to other energy programs which indirectly use the unique properties of the neutron for diagnostic and analytical purposes. The work includes the measurement of reference cross sections and related neutron data employing unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; the preservation of standard reference deposits and the development of improved neutron detectors and measurement methods. A related and essential element of the program is critical evaluation of neutron interaction data including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology. This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the third year of this three-year interagency agreement. The proposed program and required budget for the following three years are also presented. The program continues the shifts in priority instituted in order to broaden the program base.

  6. Recent progress in fast neutron activation cross section data

    International Nuclear Information System (INIS)

    A brief review is given of some significant investigations performed during the past few years in the area of fast neutron activation cross sections that may be relevant for the use of nuclear techniques in the exploration of mineral resources, in process and quality control in industry as well as for general analytical purposes. Differential capture cross sections are considered for the natural elements or isotopes of Fe, Cu, Se, Y, Nb, Cd, In, Gd, W, Os and Au. Some of the data are compared with statistical model calculations. Experimental and evaluated average cross sections for capture and threshold reactions in the spontaneous fission neutron field of 252Cf are reviewed taking into account the elements or isotopes of Mg, Al, Si, S, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Cd, In, Ba, Ta and Au. A summary of recent studies of differential cross sections for threshold reactions comprises data on Al, Si, S, Ti, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ta, W and Au. Besides experimental investigations, evaluations and theoretical model calculations are considered. Cross sections at 14 MeV and in the region around this energy are reviewed for Na, Mg, Al, Cl, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Zr, Nb, In, Er, Yb, Ta, W, Os, Ir, Au and Pb. Particular emphasis is laid on (n,p), (n,2n) and (n,α) reactions. (n,n') reactions are allowed for if the half-life of the metastable state excited permits elemental analyses by common experimental techniques. (orig.)

  7. Absolute measurements of neutron cross sections. Progress report

    International Nuclear Information System (INIS)

    In the photoneutron laboratory, we have completed a major refurbishing of experimental facilities and begun work on measurements of the capture cross section in thorium and U-238. In the 14 MeV neutron experimental bay, work continues on the measurement of 14 MeV neutron induced reactions of interest as standards or because of their technological importance. First results have been obtained over the past year, and we are extending these measurements along the lines outlined in our proposal of a year ago

  8. Summary report of technical meeting on neutron cross section covariances

    International Nuclear Information System (INIS)

    A summary is given of the Technical Meeting on Neutron Cross Section Covariances. The meeting goal was to assess covariance data needs and recommend appropriate methodologies to address those needs. Discussions on covariance data focused on three general topics: 1) Resonance and unresolved resonance regions; 2) Fast neutron region; and 3) Users' perspective: benchmarks' uncertainty and reactor dosimetry. A number of recommendations for further work were generated and the important work that remains to be done in the field of covariances was identified. (author)

  9. Coupled neutron and photon cross sections for transport calculations

    International Nuclear Information System (INIS)

    A compact set of multigroup cross sections and transfer tables for use in neutron and photon transport calculations was prepared from ENDF/B-IV using the NJOY processing system. The library includes prompt and steady-state coupled sets for neutrons and photons in FIDO format, prompt and steady-state fission spectra (chi vectors) for the fissionable isotopes, and a table of useful response functions including heating and gas production. These multigroup constants should be useful for a wide variety of problems where self-shielding is not important. 15 references

  10. Thermal neutron cross-section libraries for aromatic hydrocarbons

    Science.gov (United States)

    Cantargi, F.; Granada, J. R.

    2010-08-01

    Solid phases of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture by volume of mesitylene and toluene, were studied as potential moderator materials for a cold neutron source. Existing information on the (lattice) translational and rotational modes of the different molecular species was used to produce generalized frequency spectra; the latter included the internal vibrational modes which in turn involved the analysis of the weights of the different modes. Cross-section libraries were generated in ENDF and ACE formats for hydrogen bounded in those materials at several temperatures, and were used in Monte Carlo calculations to analyze their neutron production compared with standard cryogenic materials like liquid hydrogen and solid methane, the best moderators in terms of cold neutron production. In particular, cross-section libraries were generated at 20 K, which is a typical operating temperature for the majority of the existing cold neutron sources. It was found that those aromatic hydrocarbons produce neutron spectra which are slightly warmer than that of solid methane while presenting a high resistance to radiation, conforming in this way a new and advantageous alternative to traditional moderator materials.

  11. Generation of neutron scattering cross sections for silicon dioxide

    International Nuclear Information System (INIS)

    A set of neutron scattering cross sections for silicon and oxygen bound in silicon dioxide were generated and validated. The cross sections were generated in the ACE format for MCNP using the nuclear data processing system NJOY, and the validation was done with published experimental data. This cross section library was applied to the calculation of five critical configurations published in the benchmark Critical Experiments with Heterogeneous Compositions of Highly Enriched Uranium, Silicon Dioxide and Polyethylene. The original calculations did not use the thermal scattering libraries generated in this work and presented significant differences with the experimental results. For this reason, the newly generated library was added to the input and the multiplication factor for each configuration was recomputed. The utilization of the thermal scattering libraries did not result in an improvement of the computational results. Based on this we conclude that integral experiments to validate this type of thermal cross sections need to be designed with a higher influence of thermal scattering in the measured result, and the experiments have to be performed under more controlled conditions.

  12. Calculation of 239Pu neutron inelastic cross sections

    International Nuclear Information System (INIS)

    We have calculated cross sections for neutron-induced reactions on 239Pu between 0.001 and 5 MeV, with particular emphasis on inelastic scattering. Coupled-channel and Hauser-Feshbach statistical models were used. Within the coupled-channel calculations we employed neutron optical parameters derived from simultaneous fits to total, elastic, inelastic, and resonance data. The resulting transmission coefficients were used in Hauser-Feshbach statistical calculations having a fission channel based on a double-humped barrier representation. Barrier parameters and transition state enhancements needed to reproduce well the (n,f) cross sections between 0.001 and 5 MeV were in general agreement with those from other published analyses. Calculated compound-nucleus and direct-reaction components for inelastic scattering were combined incoherently, and the resultant cross sections agreed well with the Bruyeres-le-Chatel measurements for scattering from levels occupying the ground state rotational band. Our results are in substantial disagreement with ENDF/B-V values for these levels. We are presently performing DWBA calculations to determine direct-reaction components for states occupying higher-lying vibrational bands

  13. Influence of cross-section structure of unfolded neutron spectra

    International Nuclear Information System (INIS)

    The influence of cross-section structure on neutron spectra unfolded by multiple foil activation technique, SAND-II case, was studied. For three reactions with evident structure in neutron cross-section above threshold, 27Al(n,α)24Na, 31P(n,p)31Si, and 32S(n,p)32P, two remarkably different sets of evaluated data were selected from the available evaluations: one set of data was smooth, the structure having been averaged over by a smooth curve; while the other set was sharp, with structure given in detail. These data were used in unfolding procedure together with other reactions, the same in both cases (as well as input spectra and measured reaction rates). It was found that during unfolding calculations fewer iteration steps were needed to unfold the neutron flux spectrum with the set of sharp data. In case of smooth data it was difficult to obtain an agreement between measured and calculated activity values even by increasing the number of iteration steps. Contrary to expectations, considerable deformation of unfolded neutron flux spectrum was observed in the case of the smooth data set. 8 figures, 1 table

  14. Neutron Cross Section Libraries for Cryogenic Aromatic Moderator Materials

    International Nuclear Information System (INIS)

    The dynamics of a set of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture (by volume) of mesitylene and toluene, all of them in solid phase, was studied as potential moderator materials for cold neutron sources. Cross section libraries were generated for hydrogen bounded in those materials, at several temperatures in ACE format, and they were used in MCNP calculations to analyze their neutron production compared with traditional materials like solid methane and liquid hydrogen. In particular, cross section libraries were generated at 20 K, which is the operating temperature of the majority of the existing cold neutron sources. Although solid methane is the best moderator in terms of cold neutron production, it has very poor radiation resistance, causing spontaneous burping even at fairly low doses. Such effect is considerably reduced in the aromatic hydrocarbons. On the other hand, all of them show a similar and significant neutron production, with the exception of benzene. Even though those aromatic materials are very easy to handle, the solid phases that produce an enhanced flux of cold neutrons correspond to amorphous structures rich in low-energy excitations, and they can be created through lengthy cooling processes requiring in many cases additional annealing stages. The 3:2 mesitylene-toluene mixture, that forms in a simple and direct manner the appropriate disordered structure, constitutes an excellent cryogenic moderator material, as it is able to produce an intense flux of cold neutrons while presenting high resistance to radiation, thus conforming a new and advantageous alternative to traditional moderator materials. (authors)

  15. Neutron Cross Section Libraries for Cryogenic Aromatic Moderator Materials

    Energy Technology Data Exchange (ETDEWEB)

    Cantargi, Florencia [Centro Atomico Bariloche, CNEA, Bariloche (Argentina); Instituto Balseiro, CNEA - UN Cuyo, Bariloche (Argentina); Granada, J.R. [Centro Atomico Bariloche, CNEA, Bariloche (Argentina); Instituto Balseiro, CNEA - UN Cuyo, Bariloche (Argentina); CONICET, Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Sbaffoni, Maria Monica [Sede Central, CNEA, Buenos Aires (Argentina)

    2008-07-01

    The dynamics of a set of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture (by volume) of mesitylene and toluene, all of them in solid phase, was studied as potential moderator materials for cold neutron sources. Cross section libraries were generated for hydrogen bounded in those materials, at several temperatures in ACE format, and they were used in MCNP calculations to analyze their neutron production compared with traditional materials like solid methane and liquid hydrogen. In particular, cross section libraries were generated at 20 K, which is the operating temperature of the majority of the existing cold neutron sources. Although solid methane is the best moderator in terms of cold neutron production, it has very poor radiation resistance, causing spontaneous burping even at fairly low doses. Such effect is considerably reduced in the aromatic hydrocarbons. On the other hand, all of them show a similar and significant neutron production, with the exception of benzene. Even though those aromatic materials are very easy to handle, the solid phases that produce an enhanced flux of cold neutrons correspond to amorphous structures rich in low-energy excitations, and they can be created through lengthy cooling processes requiring in many cases additional annealing stages. The 3:2 mesitylene-toluene mixture, that forms in a simple and direct manner the appropriate disordered structure, constitutes an excellent cryogenic moderator material, as it is able to produce an intense flux of cold neutrons while presenting high resistance to radiation, thus conforming a new and advantageous alternative to traditional moderator materials. (authors)

  16. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    Energy Technology Data Exchange (ETDEWEB)

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  17. Re/Os cosmochronometer: measurement of neutron cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Mosconi, M.

    2007-12-21

    This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of {sup 187}Re (t{sub 1/2}=41.2 Gyr) into {sup 187}Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the {sup 187}Re/{sup 187}Os pair, provide the possibility to identify the radiogenic fraction of {sup 187}Os exclusively by nuclear physics considerations. Apart from its radiogenic component, {sup 187}Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, {sup 187}Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of {sup 187}Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of {sup 187}Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of {sup 186}Os, {sup 187}Os and {sup 188}Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for {sup 186}Os, {sup 187}Os, and {sup 188}Os, respectively. Since, the first excited state in {sup 187}Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, {gamma

  18. Neutron cross-section determination in geological samples (U)

    International Nuclear Information System (INIS)

    The Prompt Gamma Neutron Activation Analysis (PGAA) technique yields elemental composition data which can be used to calculate the macroscopic cross section for any sample. The Small Sample Reactivity Measurements (SSRM) technique yields the macroscopic thermal absorption directly. Experimentally, PGAA is somewhat more difficult because of the calibration and data handling than is SSRM. However, SSRM requires a mathematical model of the reactor which means a rather complicated analysis. Once the model and calibration are completed, data analysis is routine. The SSRM technique is production oriented. 9 figures

  19. Neutron cross section standards evaluations for ENDF/B-VI

    International Nuclear Information System (INIS)

    The neutron cross section standards are now being evaluated as the initial phase in the development of the new ENDF/B-VI file. These standards evaluations are following a somewhat different process compared with that used for earlier versions of ENDF. The primary effort is concentrated on a simultaneous evaluation using a generalized least squares program, R-matrix evaluations, and a procedure for combining the results of these evaluations. The ENDF/B-VI standards evaluation procedure is outlined, and preliminary simultaneous evaluation and R-matrix results are presented. 16 refs., 7 figs

  20. Neutron-induced cross-sections via the surrogate method

    International Nuclear Information System (INIS)

    The surrogate reaction method is an indirect way of determining neutron-induced cross sections through transfer or inelastic scattering reactions. This method presents the advantage that in some cases the target material is stable or less radioactive than the material required for a neutron-induced measurement. The method is based on the hypothesis that the excited nucleus is a compound nucleus whose decay depends essentially on its excitation energy and on the spin and parity state of the populated compound state. Nevertheless, the spin and parity population differences between the compound-nuclei produced in the neutron and transfer-induced reactions may be different. This work reviews the surrogate method and its validity. Neutron-induced fission cross sections obtained with the surrogate method are in general good agreement. However, it is not yet clear to what extent the surrogate method can be applied to infer radiative capture cross sections. We performed an experiment to determine the gamma decay probabilities for 176Lu and 173Yb by using the surrogate reactions 174Yb(3He,pγ)176Lu* and 174Yb(3He,αγ)173Yb*, respectively, and compare them with the well-known corresponding probabilities obtained in the 175Lu(n,γ) and 172Yb(n,γ) reactions. This experiment provides answers to understand why, in the case of gamma-decay, the surrogate method gives significant deviations compared to the corresponding neutron-induced reaction. In this work, we have also assessed whether the surrogate method can be applied to extract capture probabilities in the actinide region. Previous experiments on fission have also been reinterpreted. Thus, this work provides new insights into the surrogate method. This work is organised in the following way: in chapter 1, the theoretical aspects related to the surrogate method will be introduced. The validity of the surrogate method will be investigated by means of statistical model calculations. In chapter 2, a review on experiments based

  1. Validation of minor actinides fission neutron cross-sections

    Directory of Open Access Journals (Sweden)

    Pešić Milan P.

    2015-01-01

    Full Text Available Verification of neutron fission cross-sections of minor actinides from some recently available evaluated nuclear data libraries was carried out by comparison of the reaction rates calculated by the MCNP6.1 computer code to the experimental values. The experimental samples, containing thin layers of 235U, 237Np, 238,239,240,241Pu, 242mAm, 243Cm, 245Cm, and 247Cm, deposited on metal support and foils of 235U (pseudo-alloy 27Al + 235U, 238U, natIn, 64Zn, 27Al, and multi-component sample alloy 27Al + 55Mn + natCu + natLu + 197Au, were irradiated in the channels of the tank containing fluorine salts 0.52NaF + 0.48ZrF4, labelled as the Micromodel Salt Blanket, inserted in the lattice centre of the MAKET heavy water critical assembly at the Institute for Theoretical and Experimental Physics, Moscow. This paper is a continuation of earlier initiated scientific-research activities carried out for validation of the evaluated fission cross-sections of actinides that were supposed to be used for the quality examination of the fuel design of the accelerator driven systems or fast reactors, and consequently, determination of transmutation rates of actinides, and therefore, determination of operation parameters of these reactor facilities. These scientific-research activities were carried out within a frame of scientific projects supported by the International Science and Technology Center and the International Atomic Energy Agency co-ordinated research activities, from 1999 to 2010. Obtained results confirm that further research is needed in evaluations in order to establish better neutron cross-section data for the minor actinides and selected nuclides which could be used in the accelerator driven systems or fast reactors.

  2. Optimising neutron polarisers--measuring a single cross-section

    Energy Technology Data Exchange (ETDEWEB)

    Goossens, D.J.; Cussen, L.D. E-mail: lcu@ansto.gov.au

    2002-09-01

    This article is part of a series of works exploring the optimisation of neutron polarisation analysis measurements. It deals with measurements of individual spin flip and non-spin flip neutron scattering cross-sections. An instrumental quality factor is presented. The optimum effective thickness for gaseous spin polarised {sup 3}He transmission filters is derived and presented. Cu{sub 2}MnAl Heusler alloy polarising monochromators and supermirror devices are considered using the quality factor. Absolute comparisons are made between these different types of polarisers. The effect of instrumental background is calculated for a wide range of experimental situations. Even very small backgrounds can have a very large effect on the quality of measurements achievable indicating that great attention must be paid to background reduction on polarisation analysis instruments.

  3. Optimising neutron polarisers--measuring a single cross-section

    CERN Document Server

    Goossens, D J

    2002-01-01

    This article is part of a series of works exploring the optimisation of neutron polarisation analysis measurements. It deals with measurements of individual spin flip and non-spin flip neutron scattering cross-sections. An instrumental quality factor is presented. The optimum effective thickness for gaseous spin polarised sup 3 He transmission filters is derived and presented. Cu sub 2 MnAl Heusler alloy polarising monochromators and supermirror devices are considered using the quality factor. Absolute comparisons are made between these different types of polarisers. The effect of instrumental background is calculated for a wide range of experimental situations. Even very small backgrounds can have a very large effect on the quality of measurements achievable indicating that great attention must be paid to background reduction on polarisation analysis instruments.

  4. AFCI-2.0 Library of Neutron Cross Section Covariances

    Energy Technology Data Exchange (ETDEWEB)

    Herman, M.; Herman,M.; Oblozinsky,P.; Mattoon,C.; Pigni,M.; Hoblit,S.; Mughabghab,S.F.; Sonzogni,A.; Talou,P.; Chadwick,M.B.; Hale.G.M.; Kahler,A.C.; Kawano,T.; Little,R.C.; Young,P.G.

    2011-06-26

    Neutron cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The primary purpose of the library is to provide covariances for the Advanced Fuel Cycle Initiative (AFCI) data adjustment project, which is focusing on the needs of fast advanced burner reactors. The covariances refer to central values given in the 2006 release of the U.S. neutron evaluated library ENDF/B-VII. The preliminary version (AFCI-2.0beta) has been completed in October 2010 and made available to the users for comments. In the final 2.0 release, covariances for a few materials were updated, in particular new LANL evaluations for {sup 238,240}Pu and {sup 241}Am were adopted. BNL was responsible for covariances for structural materials and fission products, management of the library and coordination of the work, while LANL was in charge of covariances for light nuclei and for actinides.

  5. Modeling of High Precision Neutron Nonelastic Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, F S; Anderson, J D; Bauer, R W; Grimes, S M; McNabb, D P

    2007-02-05

    A new method has been applied to the determination of neutron nonelastic cross sections for iron {sup 56}Fe and lead {sup 208}Pb for energies between 5 and 26 MeV. These data have estimated errors of only a few percent and do not suffer from the ambiguities encountered in earlier nonelastic data. We attempt to fit these high precision data using both a semiclassical single phase shift model (nuclear Ramsauer model) as well as a recent global optical model that well reproduces a wide body of neutron scattering observables. At the 5% uncertainty level, both models produce satisfactory fits. However, neither model gives satisfactory fits to these new precise data. We conclude that fitting precise data, i.e., data with errors of approximately 2% or less, may require a nuclear mass dependence of radii that reflects structure effects such as shell closures.

  6. Fast neutron cross section measurements: First year progress report

    International Nuclear Information System (INIS)

    Progress on the project has generally followed the schedule included in the three year grant proposal of a year ago. In the 14 MeV Neutron Laboratory, we have completed the last of our current set of activation cross section measurements, and have moved into the phase of rebuilding our accelerator to produce pulses of one nanosecond width. This renovation has required extensive changes in the laboratory, including the relocation of the 150 kV accelerator to a balcony overlooking the main part of the Neutron Bay. We have procured and installed a 900 bending magnet, and are currently fabricating the major components of the beam pulsing system. We expect that the fabrication work will be completed near the end of the current contract year, and intend to move into initial testing of the system shortly after the start of the second contract year. In the Photoneutron Laboratory, we have demonstrated the feasibility of a series of radiochemical separations that are an essential part of our effort to carry out measurements of the U-238 capture cross section. We have also demonstrated the accuracy of a new technique to calibrate our gamma detector efficiency using alpha particle spectrometry. We are now fabricating the uranium targets for this experiment and expect that first year irradiations will take place within the next several months

  7. Curves and tables of neutron cross sections in JENDL-3.3

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tsuneo; Shibata, Keiichi (eds.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kawasaki, Hiromitsu [CRC Solutions Corp., Tokyo (Japan)

    2002-11-01

    Neutron cross sections of 337 nuclides in JENDL-3.3 are presented in figures and tables. In the tables, shown are cross sections at 0.0253 eV and 14 MeV, Maxwellian average cross sections (kT = 0.0253 eV), resonance integrals and fission spectrum average cross sections. The average cross sections calculated with typical reactor spectra are also tabulated. The numbers of delayed and total neutrons per fission are given in figures. (author)

  8. Cross-Section Measurements in the Fast Neutron Energy Range

    Science.gov (United States)

    Plompen, Arjan

    2006-04-01

    Generation IV focuses research for advanced nuclear reactors on six concepts. Three of these concepts, the lead, gas and sodium fast reactors (LFR, GFR and SFR) have fast neutron spectra, whereas a fourth, the super-critical water reactor (SCWR), can be configured to have a fast spectrum. Such fast neutron spectra are essential to meet the sustainability objective of GenIV. Nuclear data requirements for GenIV concepts will therefore emphasize the energy region from about 1 keV to 10 MeV. Here, the potential is illustrated of the GELINA neutron time-of-flight facility and the Van de Graaff laboratory at IRMM to measure the relevant nuclear data in this energy range: the total, capture, fission and inelastic-scattering cross sections. In particular, measurement results will be shown for lead and bismuth inelastic scattering for which the need was recently expressed in a quantitative way by Aliberti et al. for Accelerator Driven Systems. Even without completion of the quantitative assessment of the data needs for GenIV concepts at ANL it is clear that this particular effort is of relevance to LFR system studies.

  9. AFCI-2.0 Neutron Cross Section Covariance Library

    Energy Technology Data Exchange (ETDEWEB)

    Herman, M.; Herman, M; Oblozinsky, P.; Mattoon, C.M.; Pigni, M.; Hoblit, S.; Mughabghab, S.F.; Sonzogni, A.; Talou, P.; Chadwick, M.B.; Hale, G.M.; Kahler, A.C.; Kawano, T.; Little, R.C.; Yount, P.G.

    2011-03-01

    The cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The project builds on two covariance libraries developed earlier, with considerable input from BNL and LANL. In 2006, international effort under WPEC Subgroup 26 produced BOLNA covariance library by putting together data, often preliminary, from various sources for most important materials for nuclear reactor technology. This was followed in 2007 by collaborative effort of four US national laboratories to produce covariances, often of modest quality - hence the name low-fidelity, for virtually complete set of materials included in ENDF/B-VII.0. The present project is focusing on covariances of 4-5 major reaction channels for 110 materials of importance for power reactors. The work started under Global Nuclear Energy Partnership (GNEP) in 2008, which changed to Advanced Fuel Cycle Initiative (AFCI) in 2009. With the 2011 release the name has changed to the Covariance Multigroup Matrix for Advanced Reactor Applications (COMMARA) version 2.0. The primary purpose of the library is to provide covariances for AFCI data adjustment project, which is focusing on the needs of fast advanced burner reactors. Responsibility of BNL was defined as developing covariances for structural materials and fission products, management of the library and coordination of the work; LANL responsibility was defined as covariances for light nuclei and actinides. The COMMARA-2.0 covariance library has been developed by BNL-LANL collaboration for Advanced Fuel Cycle Initiative applications over the period of three years, 2008-2010. It contains covariances for 110 materials relevant to fast reactor R&D. The library is to be used together with the ENDF/B-VII.0 central values of the latest official release of US files of evaluated neutron cross sections. COMMARA-2.0 library contains neutron cross section covariances for 12 light nuclei (coolants and moderators), 78 structural

  10. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from Major Evaluated Data Libraries

    OpenAIRE

    Pritychenko, B.; Mughabghab, S.F.

    2012-01-01

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-...

  11. Neutron-capture Cross Sections from Indirect Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  12. Comment on "Giant absorption cross section of ultracold neutrons in Gadolinium"

    OpenAIRE

    Felber, J.; Gaehler, R.; Golub, R.

    2000-01-01

    Rauch et al (PRL 83, 4955, 1999) have compared their measurements of the Gd cross section for Ultra-cold neutrons with an exptrapolation of the cross section for thermal neutrons and interpreted the discrepancy in terms of coherence properties of the neutron. We show the extrapolation used is based on a misunderstanding and that coherence properties play no role in absorption.

  13. The Ramsauer model for the total cross sections of neutron nucleus scattering

    OpenAIRE

    Gowda, R. S.; Suryanarayana, S. S. V.; Ganesan, S

    2005-01-01

    Theoretical study of systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are of practical importance. In this paper, we analysed the experimental neutron scattering total cross sections from 20MeV to 550MeV using Ramsauer model for nuclei ranging from Be to Pb.

  14. The neutron cross-sections of Xe135

    International Nuclear Information System (INIS)

    Measurements of the total and absorption cross-sections of Xe135 reviewed briefly. The low-energy cross-section is very large and dominated by a single resonance at 0.084 eV; the spin state for this level is not known, this being one of the major uncertainties in the data. The resonance parameters given in the literature were found to give a good fit to the total cross-section but failed to reproduce the preferred 2200 m/sec. value of σγ. A new set of parameters was therefore deduced, by a least-squares analysis, which gave this preferred value of σγ and fitted the shape of the total cross section curve. To obtain this fit it was necessary to re-normalise the curve of σT by 4%. The new parameters are listed, and a discussion of the probable accuracy of the data is included. (author)

  15. On the accuracy of techniques for determining neutron compound-nucleus formation cross sections

    Directory of Open Access Journals (Sweden)

    Dietrich F.S.

    2010-03-01

    Full Text Available We consider three methods for determining neutron nonelastic cross sections: direct measurement by transmission of neutrons through a spherical shell; subtraction of the angle-integrated elastic cross section from the total cross section; and a modification of the subtraction technique using Wick’s limit that in favorable cases can significantly reduce the errors in the subtraction method. We show new results using the modified subtraction technique for nonelastic cross sections at 21.6 MeV neutron energy over a wide mass range, and discuss criteria that should be satisfied in order for the modified subtraction technique to be reliable.

  16. Neutron scattering cross sections of liquid hydrogen and deuterium for cold neutron production

    International Nuclear Information System (INIS)

    The double-differential and total cross sections for neutron scattering from liquid hydrogen and deuterium at temperatures between the melting and boiling points are calculated. It is based on a generalized cross-section model describing properly the molecular motions in the liquids in terms of individual translations and intermolecular correlations. Intramolecular motions such as the nuclear spin correlations, free rotations and harmonic vibrations are also included similarly to the Young-Koppel model. The results of numerical calculations agree very well with a variety of the experimental cross-section results, both double-differential and total, at different temperatures and in different ortho-para contents over a wide range of incident neutron energies. Furthermore it is shown that the velocity autocorrelation functions inherent in the liquids are determined successfully. (author)

  17. Estimation of neutron energy for first resonance from absorption cross section for thermal neutrons

    Science.gov (United States)

    Bogart, Donald

    1951-01-01

    Examination of published data for some 52 isotopes indicates that the neutron energy for which the first resonance occurs is related to the magnitude of the thermal absorption cross section. The empirical relation obtained is in qualitative agreement with the results of a simplified version of the resonance theory of the nucleus of Breit-Wigner.

  18. Evaluation of the neutron cross sections for Pu-240

    International Nuclear Information System (INIS)

    The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for 240Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs

  19. Measurement of fast-neutron capture cross sections for 75As

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The cross sections of the 75As(n,γ)76As reaction were measured in the neutron energy range from 0.50 to 1.50 MeV by using the activation technique. Neutrons were produced via the T(p,n)3He reaction and the cross sections of the 197Au(n,γ)198Au reaction were used to determine the absolute neutron flux. Present results are compared with existing measurements and evaluations.

  20. Evaluation of Cm-247 neutron cross sections in the resonance region

    International Nuclear Information System (INIS)

    The neutron cross sections of Cm-247 are evaluated in the resonance (resolved and unresolved) region up to 10 keV. Average resonance parameters (i.e. spacing D, fission and radiative widths, neutron strength functions) are determined for unresolved region calculations. Moreover for a better comparison with the experimental data, fission cross section is calculated up to 10 MeV. In addition, the average number of neutrons emitted per fission as a function of energy is estimated

  1. Neutron total cross section measurements of gold and tantalum at the nELBE photoneutron source

    CERN Document Server

    Hannaske, Roland; Beyer, Roland; Junghans, Arnd; Bemmerer, Daniel; Birgersson, Evert; Ferrari, Anna; Grosse, Eckart; Kempe, Mathias; Kögler, Toni; Marta, Michele; Massarczyk, Ralph; Matic, Andrija; Schramm, Georg; Schwengner, Ronald; Wagner, Andreas

    2014-01-01

    Neutron total cross sections of 197 Au and nat Ta have been measured at the nELBE photoneutron source in the energy range from 0.1 - 10 MeV with a statistical uncertainty of up to 2 % and a total systematic uncertainty of 1 %. This facility is optimized for the fast neutron energy range and combines an excellent t ime structure of the neutron pulses (electron bunch width 5 ps) with a short flight path of 7 m. Because of the low instantaneous neutron flux transmission measurements of neutron total cross sections are possible, that exhibit very different beam and back ground conditions than found at other neutron sources.

  2. Neutron total cross section measurements of gold and tantalum at the nELBE photoneutron source

    CERN Document Server

    Hannaske, Roland; Beyer, Roland; Junghans, Arnd; Bemmerer, Daniel; Birgersson, Evert; Ferrari, Anna; Grosse, Eckart; Kempe, Mathias; Kögler, Toni; Marta, Michele; Massarczyk, Ralph; Matic, Andrija; Schramm, Georg; Schwengner, Ronald; Wagner, Andreas

    2013-01-01

    Neutron total cross sections of $^{197}$Au and $^\\text{nat}$Ta have been measured at the nELBE photoneutron source in the energy range from 0.1 - 10 MeV with a statistical uncertainty of up to 2 % and a total systematic uncertainty of 1 %. This facility is optimized for the fast neutron energy range and combines an excellent time structure of the neutron pulses (electron bunch width 5 ps) with a short flight path of 7 m. Because of the low instantaneous neutron flux transmission measurements of neutron total cross sections are possible, that exhibit very different beam and background conditions than found at other neutron sources.

  3. Measurement of reaction cross sections of fission products induced by DT neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan)

    1998-03-01

    With the view of future application of fusion reactor to incineration of fission products, we have measured the {sup 129}I(n,2n){sup 128}I reaction cross section by DT neutrons with the activation method. The measured cross section was compared with the evaluated nuclear data of JENDL-3.2. From the result, it was confirmed that the evaluation overestimated the cross section by about 20-40%. (author)

  4. Modeled Neutron Induced Nuclear Reaction Cross Sections for Radiochemistry in the region of Iriduim and Gold

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Dietrich, F S; Kelley, K; Escher, J; Bauer, R; Mustafa, M

    2008-02-26

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.

  5. Partial neutron capture cross sections of actinides using cold neutron prompt gamma activation analysis

    International Nuclear Information System (INIS)

    Nuclear waste needs to be characterized for its safe handling and storage. In particular long-lived actinides render the waste characterization challenging. The results described in this thesis demonstrate that Prompt Gamma Neutron Activation Analysis (PGAA) with cold neutrons is a reliable tool for the non-destructive analysis of actinides. Nuclear data required for an accurate identification and quantification of actinides was acquired. Therefore, a sample design suitable for accurate and precise measurements of prompt γ-ray energies and partial cross sections of long-lived actinides at existing PGAA facilities was presented. Using the developed sample design the fundamental prompt γ-ray data on 237Np, 241Am and 242Pu were measured. The data were validated by repetitive analysis of different samples at two individual irradiation and counting facilities - the BRR in Budapest and the FRM II in Garching near Munich. Employing cold neutrons, resonance neutron capture by low energetic resonances was avoided during the experiments. This is an improvement over older neutron activation based works at thermal reactor neutron energies. 152 prompt γ-rays of 237Np were identified, as well as 19 of 241Am, and 127 prompt γ-rays of 242Pu. In all cases, both high and lower energetic prompt γ-rays were identified. The most intense line of 237Np was observed at an energy of Eγ=182.82(10) keV associated with a partial capture cross section of σγ=22.06(39) b. The most intense prompt γ-ray lines of 241Am and of 242Pu were observed at Eγ=154.72(7) keV with σγ=72.80(252) b and Eγ=287.69(8) keV with σγ=7.07(12) b, respectively. The measurements described in this thesis provide the first reported quantifications on partial radiative capture cross sections for 237Np, 241Am and 242Pu measured simultaneously over the large energy range from 45 keV to 12 MeV. Detailed uncertainty assessments were performed and the validity of the given uncertainties was demonstrated. Compared

  6. An empirical fit to estimated neutron emission cross sections from proton induced reactions

    Indian Academy of Sciences (India)

    Moumita Maiti; Maitreyee Nandy; S N Roy; P K Sarkar

    2003-01-01

    Neutron emission cross section for various elements from 9Be to 209Bi have been calculated using the hybrid model code ALICE-91 for proton induced reactions in the energy range 25 MeV to 105 MeV. An empirical expression relating neutron emission cross section to target mass number and incident proton energy has been obtained. The simple expression reduces the computation time significantly. The trend in the variation of neutron emission cross sections with respect to the target mass number and incident proton energy has been discussed within the framework of the model used.

  7. Neutron cross section standards for the energy region above 20 MeV

    International Nuclear Information System (INIS)

    These proceedings of a specialists' meeting on Neutron cross section standards for the energy region above 20 MeV are divided into 6 sessions bearing on: - session 1: status of the date base for (n-p) scattering (2 conferences) - session 2: status of nucleon-nucleon phase shift calculations (1 conference) - session 3: recent and planned experimental work on n-p cross section measurements and facilities (7 conferences) - session 4: Instruments for utilizing the H (n.n) standard for neutron fluence measurement (4 conferences) - session 5: proposal for other neutron cross-section standards (4 conferences) - session 6: monitor reactions for radiation dosimetry (3 conferences)

  8. Neutron capture and total cross-section measurements on fast reactor structural materials

    International Nuclear Information System (INIS)

    The neutron capture and total cross-sections of a series of nuclides in the mass range 46 to 62 have been measured at Harwell by the time-of-flight method. The capture cross-sections were measured for incident neutron energies from a few eV to 800 keV using the neutron booster target of the 45 MeV electron linac. High resolution total cross-section measurements were made with the transmission facility on the 160 MeV proton synchrocyclotron. The results of preliminary analyses of the data are presented on the capture cross-sections of Fe, 47Ti, and 49Ti and the total cross-sections of 56Fe, 58Ni and 60Ni. (author)

  9. Resonance analysis and evaluation of the 235U neutron induced cross sections

    International Nuclear Information System (INIS)

    Neutron cross sections of fissile nuclei are of considerable interest for the understanding of parameters such as resonance absorption, resonance escape probability, resonance self-shielding,and the dependence of the reactivity on temperature. In the present study, new techniques for the evaluation of the 235U neutron cross sections are described. The Reich-Moore formalism of the Bayesian computer code SAMMY was used to perform consistent R-matrix multilevel analyses of the selected neutron cross-section data. The Δ3-statistics of Dyson and Mehta, along with high-resolution data and the spin-separated fission cross-section data, have provided the possibility of developing a new methodology for the analysis and evaluation of neutron-nucleus cross sections. The results of the analysis consists of a set of resonance parameters which describe the 235U neutron cross sections up to 500 eV. The set of resonance parameters obtained through a R-matrix analysis are expected to satisfy statistical properties which lead to information on the nuclear structure. The resonance parameters were tested and showed good agreement with the theory. It is expected that the parametrization of the 235U neutron cross sections obtained in this dissertation represents the current state of art in data as well as in theory and, therefore, can be of direct use in reactor calculations. 44 refs., 21 figs., 8 tabs

  10. Systematic Characteristics of Fast Neutron Fission Cross Sections for Actinide Nuclei

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The neutron fission cross sections of actinide nuclei are important data for the design of nuclear reactor and nuclear engineering, and so on. So far, there has been a certain amount of experimental data for the fission cross sections of actinide nuclei. However,

  11. Absolute cross-section normalization of magnetic neutron scattering data

    OpenAIRE

    Xu, Guangyong; Xu, Zhijun; Tranquada, J. M.

    2013-01-01

    We discuss various methods to obtain the resolution volume for neutron scattering experiments, in order to perform absolute normalization on inelastic magnetic neutron scattering data. Examples from previous experiments are given. We also try to provide clear definitions of a number of physical quantities which are commonly used to describe neutron magnetic scattering results, including the dynamic spin correlation function and the imaginary part of the dynamic susceptibility. Formulas that c...

  12. Measurement of neutron captured cross-sections in 1-2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gi Dong; Kim, Young Sek; Kim, Jun Kon; Yang, Tae Keun [Korea Institutes of Geoscience and Mineral Resources, Taejeon (Korea)

    2001-04-01

    The measurement of neutron captured reaction cross sections was performed to build the infra system for the production of nuclear data. MeV neutrons were produced with TiT target and {sup 3}T(p,n){sup 3}He reaction. The characteristics of TiT thin film was analyzed with ERD-TOF and RBS. The results was published at Journal of the Korea Physical Society (SCI registration). The energy, the energy spread and the flux of the produced neutron were measured. The neutron excitation functions of {sup 12}C and {sup 16}O were obtained to confirm the neutron energy and neutron energy spread. The neutron energy spread found to be 1.3 % at the neutron energy of 2.077 MeV. The {sup 197}Au(n,{gamma}) reaction was performed to obtain the nerutron flux. The maximum neutron flux found to be 1 x 10{sup 8} neutrons/sec at the neutron energy of 2 MeV. The absolute efficiency of liquid scintillation detector was obtained in the neutron energy of 1 - 2 MeV. The fast neutron total reaction cross sections of Cu, Fe, and Au were measured with sample in-out method. Also the neutron captured reaction cross sections of {sup 63}Cu were measured with fast neutron activation method. The measurement of neutron total reaction cross sections and the neutron captured reaction cross sections with fast neutrons were first tried in Korea. The beam pulsing system was investigated and the code of calculating the deposition spectrums for primary gamma rays was made to have little errors at nuclear data. 25 refs., 28 figs., 14 tabs. (Author)

  13. Neutron cross-section probability tables in TRIPOLI-3 Monte Carlo transport code

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, S.H.; Vergnaud, T.; Nimal, J.C. [Commissariat a l`Energie Atomique, Gif-sur-Yvette (France). Lab. d`Etudes de Protection et de Probabilite

    1998-03-01

    Neutron transport calculations need an accurate treatment of cross sections. Two methods (multi-group and pointwise) are usually used. A third one, the probability table (PT) method, has been developed to produce a set of cross-section libraries, well adapted to describe the neutron interaction in the unresolved resonance energy range. Its advantage is to present properly the neutron cross-section fluctuation within a given energy group, allowing correct calculation of the self-shielding effect. Also, this PT cross-section representation is suitable for simulation of neutron propagation by the Monte Carlo method. The implementation of PTs in the TRIPOLI-3 three-dimensional general Monte Carlo transport code, developed at Commissariat a l`Energie Atomique, and several validation calculations are presented. The PT method is proved to be valid not only in the unresolved resonance range but also in all the other energy ranges.

  14. Proceedings of a specialists' meeting on neutron activation cross sections for fission and fusion energy applications

    International Nuclear Information System (INIS)

    These proceedings of a specialists' meeting on neutron activation cross sections for fission and fusion energy applications are divided into 4 sessions bearing on: - data needs: 4 conferences - experimental work: 11 conferences - theoretical work: 4 conferences - evaluation work: 5 conferences

  15. Removal cross sections and total mass attenuation coefficients of fast neutrons and gamma rays for steel

    CERN Document Server

    Elsayed, A A

    2003-01-01

    The present work deals with the study of the attenuation properties and determination of the cross sections of fast neutrons and gamma rays for structure steel used in different applications in nuclear power plants, particle accelerators, research reactors and different radiation attenuation fields. Investigation has been performed by measuring the transmitted fast neutron and gamma ray spectra behind cylindrical samples of steel (rho=7.87 gem sup - sup 3) of different thicknesses. A reactor collimated beam and neutron - gamma spectrometer with stiblbene scintillator were used for measurements. The pluse shape disriminate technique based on zero cross over method was used to discriminate between neutron and gamma ray pulses. Effective removal cross-section (sigma sub R) and total mass attenuation coefficient (mu) of neureons and gamma rays have been achieved using the attenuation relations. Microscopic removal cross sections sigma sup 9 sup 8 and mass removal cross sections sigma sub R sub / subrho of fast ne...

  16. Calculation of production cross sections of γ-rays from thermal-neutron captures

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chun-Mei; WU Zhen-Dong

    2004-01-01

    The calculation methods of production cross sections of γ-rays for thermal-neutron captures are briefly presented. The check of intensity balance is made. The examples are given to illustrate its application.

  17. Measurement of neutron total cross-sections of 209Bi at the Pohang Neutron Facility

    CERN Document Server

    Wang, Tao-Feng; Kim, Guinyun

    2014-01-01

    Measurements of neutron total cross-sections of natural bismuth in the neutron energy region from 0.1 eV to 100 eV have been performed by using the time-of-flight method at the Pohang Neutron Facility, which consists of an electron linear accelerator, a water-cooled tantalum target with a water moderator, and a 12-m-long time-of-flight path. A 6Li-ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of 1.6 cm is employed as a neutron detector, and a piece of high purity natural bismuth metallic plates with a thickness of 3 mm is used for the neutron transmission measurement. The present results were compared with the evaluated data from ENDF/B VII.1 and other previous reported experimental data.

  18. Total cross section of neutron-proton scattering at low energies in quark-gluon model

    OpenAIRE

    Abramovsky, V. A.; Radchenko, N. V.

    2011-01-01

    We show that analysis of nonrelativistic neutron-proton scattering in a framework of relativistic QCD based quark model can give important information about QCD vacuum structure. In this model we describe total cross section of neutron-proton scattering at kinetic energies of projectile neutron from 1 eV up to 1 MeV.

  19. Numerical estimates of multiple reaction corrections in neutron cross-section measurements

    International Nuclear Information System (INIS)

    A method to evaluate the effect of secondary neutrons in 14-15 MeV neutron cross-section measurements is presented. The emission spectra of secondary neutrons are calculated by means of the preequilibrium and statistical models. An expression for the collision probability in a homogenous body has been utilized in the calculations. (author)

  20. Comparative analysis of the neutron cross-sections of iron from various evaluated data libraries

    International Nuclear Information System (INIS)

    The comparative analysis of neutron cross-sections of iron from evaluated nuclear data libraries SOKRATOR, KEDAK, ENDL is done in energy interval from 0.025 eV to 20 MeV. Some of iron cross-sections from SOKRATOR library are revised and new data, which are obtained by using new experimental data and more comprehensive theoretical methods, are recommended. As a result the new version of the iron neutron cross-section file (BNF-2012) is produced for SOKRATOR library. (author)

  1. Results of coupled channels calculations for the neutrons cross sections of a set of actinide nuclei

    International Nuclear Information System (INIS)

    This report gathers recents results of neutrons interactions with the following actinide nuclei: 230Th, 232Th, 234U, 238U, 242Pu, 246Cm and 252Cf from the use of the coupled channels optical model. Tabulations of the following quantities are given in Annexe: total, direct elastic and inelastic scattering (integrated and differential), and compound nucleus formation cross sections; ground state generalized transmission coefficients needed to calculate the cross sections of partial compound nucleus processes. This work was carried out within the framework of the IAEA-NDS Coordinated Research Programme on the Intercomparison of Actinide Neutron Cross Section Evaluations

  2. Neutron total and scattering cross sections of 6Li in the few MeV region

    International Nuclear Information System (INIS)

    Neutron total cross sections of 6Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of 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;α)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

  3. RAON neutron science facility design for measuring neutron-induced cross-section

    Directory of Open Access Journals (Sweden)

    Kim Jae Cheon

    2014-03-01

    Full Text Available A heavy-ion accelerator complex called RAON is currently under development in Korea. The neutron science facility (NSF is a part of RAON to produce white and mono-energetic neutrons covering the 10-90 MeV energy range with high-intensity. Deuterons and protons with ≤ 53 MeV and ≤ 88 MeV, respectively, accelerated by superconducting linac are delivered to the neutron target to produce fast neutrons. Pulsed beam intense is up to more than ∼ 20μA enough for measurements of neutron-induced reactions at the neutron time-of-flight (n-TOF facility. Be and C target are used to produce white neutrons and Li target is used for mono-energetic neutrons. Basically, two neutron beam lines at 0 ° and 30 ° will be constructed by using neutron collimator. In NSF, the time projection counter (TPC is employed to measure fission cross-section with ∼few % uncertainty.

  4. Self-shielding in large cross-section neutron absorbers

    International Nuclear Information System (INIS)

    This study is dealing with finding the effects on neutron regime in several cases, among them a fuel bundle comprised of 16 fuel rods, made of sintered UO2 pellets clad in zircaloy-4 and irradiated in the neutron trap. The variations of the average neutron flux and the effect of self-shielding were studied. Similar calculations were carried out, both theoretically and experimentally for samples of europium oxide. Self-shielding effects were studied, and the variation of the effective multiplication factor was found as function of mass. The isotope generation and depletion code origin was used to compute the radioactivity of fission products from irradiating uranium different enrichments in IRT-5000. The effect of self-shielding on the flux and on the activities were found also. 14 tabs.; 34 figs.; 27 refs

  5. Observation of Large Enhancement of Charge Exchange Cross Sections with Neutron-Rich Carbon Isotopes

    CERN Document Server

    Tanihata, I; Kanungo, R; Ameil, F; Atkinson, J; Ayyad, Y; Cortina-Gil, D; Dillmann, I; Estradé, A; Evdokimov, A; Farinon, F; Geissel, H; Guastalla, G; Janik, R; Knoebel, R; Kurcewicz, J; Litvinov, Yu A; Marta, M; Mostazo, M; Mukha, I; Nociforo, C; Ong, H J; Pietri, S; Prochazka, A; Scheidenberger, C; Sitar, B; Strmen, P; Takechi, M; Tanaka, J; Toki, H; Vargas, J; Winfield, J S; Weick, H

    2015-01-01

    Production cross sections of nitrogen isotopes from high-energy carbon isotopes on hydrogen and carbon targets have been measured for the first time for a wide range of isotopes. The fragment separator FRS at GSI was used to deliver C isotope beams. The cross sections of the production of N isotopes were determined by charge measurements of forward going fragments. The cross sections show a rapid increase with the number of neutrons in the projectile. Since the production of nitrogen is mostly due to charge exchange reactions below the proton separation energies, the present data suggests a concentration of Gamow-Teller and Fermi transition strength at low excitation energies for neutron-rich isotopes. It was also observed that the cross sections were enhanced much more strongly for neutron rich isotopes in the C-target data.

  6. Measurements of Thermal Neutron Capture Cross Sections of 136Ce, 156Dy, and 168Yb

    Science.gov (United States)

    Lee, J. Y.; Kim, Y. D.; Sun, G. M.

    2014-05-01

    For several low abundance stable nuclei, the thermal neutron capture cross sections are not well measured, while the cross sections for isotopes with high abundances are already well measured. Our experiments, different from the commonly used method of using gold foil as reference, are performed using natural foils for which we know the relative abundances of all isotopes and thermal neutron capture cross sections. Therefore, we can obtain the cross sections of low abundance isotopes, which are not known well, by comparing the yields of gammas from the neutron captures by various isotopes in the foils. The advantage of this method is the cancellation of potential systematic errors from thermal neutron flux, flux profile, foil thickness, foil size, and irradiation time. We have measured the thermal capture cross sections of 136Ce, 156Dy, and 168Yb isotopes, using the high thermal neutron flux from the reactor HANARO at KAERI, and have obtained new cross section values of 7.64±0.63 barn for 136Ce, 14.8±2.0 barn for 156Dy, and 1335±43 barn for 168Yb.

  7. Neutron source investigations in support of the cross section program at the Argonne Fast-Neutron Generator

    International Nuclear Information System (INIS)

    Experimental methods related to the production of neutrons for cross section studies at the Argonne Fast-Neutron Generator are reviewed. Target assemblies commonly employed in these measurements are described, and some of the relevant physical properties of the neutron source reactions are discussed. Various measurements have been performed to ascertain knowledge about these source reaction that is required for cross section data analysis purposes. Some results from these studies are presented, and a few specific examples of neutron-source-related corrections to cross section data are provided. 16 figures, 3 tables

  8. Neutron total and scattering cross sections of some even isotopes of molybdenum and the optical model

    International Nuclear Information System (INIS)

    Neutron total and elastic and inelastic scattering cross sections of 92Mo, 96Mo, 98Mo and 100Mo were measured. Neutron total cross sections were determined at intervals of less than or equal to 10 keV from 1.6 to 5.5 MeV with resolutions of approximately 10 keV. Neutron elastic and inelastic scattering cross sections were measured from 1.8 to 4.0 MeV at intervals of 0.2 MeV. Neutron groups corresponding to the excitation of forty states were identified. The experimental results were examined in the context of optical- and statistical-nuclear models. It was concluded that the real part of the optical potential includes a term proportional to [(N - Z)/A] and suggested that the imaginary part is shell dependent with decreasing magnitude as N = 50 is approached. Comparison of measured and calculated inelastic neutron excitation cross sections suggested a number of J/sup π/ assignments extending previous knowledge. The experimental and calculational results were used, together with previously reported values, to generate an evaluated neutron total and scattering cross section file in the ENDF format extending over the energy range 0.1 to 8.0 MeV

  9. Neutron cross-sections database for amino acids and proteins analysis

    International Nuclear Information System (INIS)

    Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)

  10. Neutron cross-sections database for amino acids and proteins analysis

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin, E-mail: dante@ien.gov.br, E-mail: fferreira@ien.gov.br, E-mail: Chaffin@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da, E-mail: hrocha@gbl.com.br [Universidade Federal do Rio de Janeiro (IPPMG/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pediatria

    2015-07-01

    Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)

  11. High-energy neutron-induced fission cross sections of natural lead and bismuth-209

    OpenAIRE

    Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme

    2011-01-01

    The CERN Neutron Time-Of-Flight (n TOF) facility is well suited to measure small neutron- induced ssion cross sections, as those of subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the ssion events. The present experiment provides the rst results for neutron-induced ssion up to 1 GeV for natPb and 209Bi. A good agreement with previous exper...

  12. Use of Neutron Benchmark Fields for the Validation of Dosimetry Cross Sections

    Science.gov (United States)

    Griffin, Patrick

    2016-02-01

    The evolution of validation metrics for dosimetry cross sections in neutron benchmark fields is explored. The strength of some of the metrics in providing validation evidence is examined by applying them to the 252Cf spontaneous fission standard neutron benchmark field, the 235U thermal neutron fission reference benchmark field, the ACRR pool-type reactor central cavity reference benchmark fields, and the SPR-III fast burst reactor central cavity. The IRDFF dosimetry cross section library is used in the validation study and observations are made on the amount of coverage provided to the library contents by validation data available in these benchmark fields.

  13. Expected anomalies of the neutron cross section near the liquid-glass transition

    International Nuclear Information System (INIS)

    In the frameworks of a microscopic theory the anomalies of the neutron cross section near the liquid-glass transition are discussed. The central concept of the theory is the correlation function for density fluctuations of wave vector q and frequency ω. Its absorptive part is proportional to the dynamical structure factor S(q, ω), this is the scattering law for coherent neutron scattering. Tagged particle motion is evaluated as well and it yields the incoherent neutron scattering cross section Si(q, ω) in. The predictions of the theory for S(q, ω) and Si (q, ω) a q-ω domain are given

  14. High-energy Neutron-induced Fission Cross Sections of Natural Lead and Bismuth-209

    CERN Document Server

    Tarrio, D; Carrapico, C; Eleftheriadis, C; Leeb, H; Calvino, F; Herrera-Martinez, A; Savvidis, I; Vlachoudis, V; Haas, B; Koehler, P; Vannini, G; Oshima, M; Le Naour, C; Gramegna, F; Wiescher, M; Pigni, M T; Audouin, L; Mengoni, A; Quesada, J; Becvar, F; Plag, R; Cennini, P; Mosconi, M; Rauscher, T; Couture, A; Capote, R; Sarchiapone, L; Vlastou, R; Domingo-Pardo, C; Dillmann, I; Pavlopoulos, P; Karamanis, D; Krticka, M; Jericha, E; Ferrari, A; Martinez, T; Trubert, D; Oberhummer, H; Karadimos, D; Plompen, A; Isaev, S; Terlizzi, R; Cortes, G; Cox, J; Cano-Ott, D; Pretel, C; Colonna, N; Berthoumieux, E; Vaz, P; Heil, M; Lopes, I; Lampoudis, C; Walter, S; Calviani, M; Gonzalez-Romero, E; Embid-Segura, M; Stephan, C; Igashira, M; Papachristodoulou, C; Aerts, G; Tavora, L; Berthier, B; Rudolf, G; Andrzejewski, J; Villamarin, D; Ferreira-Marques, R; Tain, J L; O'Brien, S; Reifarth, R; Kadi, Y; Neves, F; Poch, A; Kerveno, M; Rubbia, C; Lazano, M; Dahlfors, M; Wisshak, K; Salgado, J; Dridi, W; Ventura, A; Andriamonje, S; Assimakopoulos, P; Santos, C; Voss, F; Ferrant, L; Patronis, N; Chiaveri, E; Guerrero, C; Perrot, L; Vicente, M C; Lindote, A; Praena, J; Baumann, P; Kappeler, F; Rullhusen, P; Furman, W; David, S; Marrone, S; Tassan-Got, L; Gunsig, F; Alvarez-Velarde, F; Massimi, C; Mastinu, P; Pancin, J; Papadopoulos, C; Tagliente, G; Haight, R; Chepel, V; Kossionides, E; Badurek, G; Marganiec, J; Lukic, S; Pavlik, A; Goncalves, I; Duran, I; Alvarez, H; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C

    2011-01-01

    The CERN Neutron Time-Of-Flight (n\\_TOF) facility is well suited to measure small neutron-induced fission cross sections, as those of subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the fission events. The present experiment provides the first results for neutron-induced fission up to 1 GeV for (nat)Pb and (209)Bi. A good agreement with previous experimental data below 200 MeV is shown. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross section is close to 1 GeV.

  15. Neutron capture on (94)Zr: Resonance parameters and Maxwellian-averaged cross sections

    CERN Document Server

    Tagliente, G; Fujii, K; Abbondanno, U; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Bisterzo, S; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Goncalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tain, J.L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M.C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus (90)Zr and through (91,92,93,94)Zr, but only part of the flow extends to (96)Zr because of the branching point at (95)Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n, gamma) cross sections make Zr also an interesting structural material for nuclear reactors. The (94)Zr (n, gamma) cross section has been measured with high resolution at the spallation neutron source n_TOF at CERN and resonance parameters are reported up to 60 keV neutron energy.

  16. Cross-Section Measurements for Elastic and Inelastic Scattering of Neutrons from Noble Gases

    Science.gov (United States)

    Macmullin, Sean; Kidd, Mary; Tornow, Werner; Howell, Calvin; Brown, Michael; Henning, Reyco

    2010-11-01

    Neutron backgrounds are a significant concern to experiments that attempt to directly detect Weakly Interacting Massive Particle (WIMP) dark matter. Recoil nuclei produced by neutron elastic scattering can mimic WIMP signatures. There is insufficient experimental data available for the scattering cross-sections of neutrons with noble gases (Ne, Ar, Xe), which are candidate target materials for such experiments. Neutron elastic and inelastic scattering from neon of natural abundance was investigated at the Triangle Universities Nuclear Laboratory at neutron energies relevant to (α,n) and low-energy spallation neutron backgrounds in these experiments. The differential cross-section was measured using a time-of-flight technique at neutron energies of 8.0 and 5.0 MeV. Details of the experimental technique and current status of measurements will be presented.

  17. Formalism for neutron cross section covariances in the resonance region using kernel approximation

    Energy Technology Data Exchange (ETDEWEB)

    Oblozinsky, P.; Cho,Y-S.; Matoon,C.M.; Mughabghab,S.F.

    2010-04-09

    We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).

  18. Graphs of neutron cross sections in JSD1000 for radiation shielding safety analysis

    International Nuclear Information System (INIS)

    Graphs of neutron cross sections and self-shielding factors in the JSD1000 library are presented for radiation shielding safety analysis. The compilation contains various reaction cross sections for 42 nuclides from 1H to 241Am in the energy range from 3.51 x 10-4 eV to 16.5 MeV. The Bondarenko-type self-shielding factors of each reaction are given by the background cross sections from σ0 = 0 to σ0 = 10000. (author)

  19. Covariance of Neutron Cross Sections for {sup 16}O through R-matrix Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kunieda, S., E-mail: kunieda.satoshi@jaea.go.jp [Japan Atomic Energy Agency, Tokai-mura Naka-gun, Ibaraki 319-1195 (Japan); Kawano, T.; Paris, M.; Hale, G.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Shibata, K.; Fukahori, T. [Japan Atomic Energy Agency, Tokai-mura Naka-gun, Ibaraki 319-1195 (Japan)

    2015-01-15

    Through the R-matrix analysis, neutron cross sections as well as the covariance are estimated for {sup 16}O in the resolved resonance range. Although we consider the current results are still preliminary, we present the summary of the cross section analysis and the results of data uncertainty/covariance, including those for the differential cross sections. It is found that the values obtained highlight consequences of nature in the theory as well as knowledge from measurements, which gives a realistic quantification of evaluated nuclear data covariances.

  20. Study of the molecular structure and dynamics of bakelite with neutron cross section measurements

    International Nuclear Information System (INIS)

    The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 8000 C. (F.E.). 65 refs, 31 figs, 5 tabs

  1. Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Takafumi; Suzuki, Soju [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-03-01

    Activation cross sections of tag gas nuclides, which will be used for the failed fuel detection and location in FBR plants, were evaluated by the irradiation tests in the fast neutron spectrum fields in JOYO and YAYOI. The comparison of their measured radioactivities and the calculated values using the JENDL-3.2 cross section set showed that the C/E values ranged from 0.8 to 2.8 for the calibration tests in YAYOI and that the present accuracies of these cross sections were confirmed. (author)

  2. Stellar neutron capture cross sections of 41K and 45Sc

    Science.gov (United States)

    Heil, M.; Plag, R.; Uberseder, E.; Bisterzo, S.; Käppeler, F.; Mengoni, A.; Pignatari, M.

    2016-05-01

    The neutron capture cross sections of light nuclei (A neutron poisons. We report on measurements of the neutron capture cross sections of 41K and 45Sc, which were performed at the Karlsruhe 3.7 MV Van de Graaff accelerator via the activation method in a quasistellar neutron spectrum corresponding to a thermal energy of k T =25 keV. Systematic effects were controlled by repeated irradiations, resulting in overall uncertainties of less than 3%. The measured spectrum-averaged data have been used to normalize the energy-dependent (n ,γ ) cross sections from the main data libraries JEFF-3.2, JENDL-4.0, and ENDF/B-VII.1, and a set of Maxwellian averaged cross sections was calculated for improving the s -process nucleosynthesis yields in AGB stars and in massive stars. At k T =30 keV, the new Maxwellian averaged cross sections of 41K and 45Sc are 19.2 ±0.6 mb and 61.3 ±1.8 mb, respectively. Both values are 20% lower than previously recommended. The effect of neutron poisons is discussed for nuclei with A <56 in general and for the investigated isotopes in particular.

  3. Secondary neutron-production cross sections from heavy-ioninteractions in composite targets.

    Energy Technology Data Exchange (ETDEWEB)

    Heilbronn, L.; Iwata, Y.; Iwase,H.; Murakami, T.; Sato, H.; Nakamura, T.; Ronningen, R.M.; Ieki, K.; Gudowska, I.; Sobolevsky, N.

    2005-12-19

    Secondary neutron-production cross-sections have been measured from interactions of 290 MeV/nucleon C and 600 MeV/nucleon Ne in a target composed of simulated Martian regolith and polyethylene, and from 400 MeV/nucleon Ne interactions in wall material from the International Space Station. The data were measured between 5 and 80 deg in the laboratory. We report the double-differential cross sections, angular distributions, and total neutron-production cross sections from all three systems. The spectra from all three systems exhibit behavior previously reported in other heavy-ion, neutron production experiments; namely, a peak at forward angles near the energy corresponding to the beam velocity, with the remaining spectra generated by pre-equilibrium and equilibrium processes. The double differential cross sections are fitted with a moving-source parameterization. Also reported are the data without corrections for neutron flux attenuation in the target and other intervening materials, and for neutron production in non-target materials near the target position. These uncorrected spectra are compared with SHIELD-HIT and PHITS transport model calculations. The transport model calculations reproduce the spectral shapes well, but, on average, underestimate the magnitudes of the cross sections.

  4. Neutron Capture Cross Section Measurement on $^{238}$Pu at DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Chyzh, A; Wu, C Y

    2011-02-14

    The proposed neutron capture measurement for {sup 238}Pu was carried out in Nov-Dec, 2010, using the DANCE array at LANSCE, LANL. The total beam-on-target time is about 14 days plus additional 5 days for the background measurement. The target was prepared at LLNL with the new electrplating cell capable of plating the {sup 238}Pu isotope simultaneously on both sides of the 3-{micro}m thick Ti backing foil. A total mass of 395 {micro}g with an activity of 6.8 mCi was deposited onto the area of 7 mm in diameter. The {sup 238}Pu sample was enriched to 99.35%. The target was covered by 1.4 {micro}m double-side aluminized mylar and then inserted into a specially designed vacuum-tight container, shown in Fig. 1, for the {sup 238}Pu containment. The container was tested for leaks in the vacuum chamber at LLNL. An identical container without {sup 238}Pu was made as well and used as a blank for the background measurement.

  5. Neutron Capture Cross Section Measurement on 238Pu at DANCE

    International Nuclear Information System (INIS)

    The proposed neutron capture measurement for 238Pu was carried out in Nov-Dec, 2010, using the DANCE array at LANSCE, LANL. The total beam-on-target time is about 14 days plus additional 5 days for the background measurement. The target was prepared at LLNL with the new electrplating cell capable of plating the 238Pu isotope simultaneously on both sides of the 3-(micro)m thick Ti backing foil. A total mass of 395 (micro)g with an activity of 6.8 mCi was deposited onto the area of 7 mm in diameter. The 238Pu sample was enriched to 99.35%. The target was covered by 1.4 (micro)m double-side aluminized mylar and then inserted into a specially designed vacuum-tight container, shown in Fig. 1, for the 238Pu containment. The container was tested for leaks in the vacuum chamber at LLNL. An identical container without 238Pu was made as well and used as a blank for the background measurement.

  6. Neutron-induced capture cross sections of short-lived actinides with the surrogate reaction method

    Directory of Open Access Journals (Sweden)

    Gunsing F.

    2010-03-01

    Full Text Available Determination of neutron-capture cross sections of short-lived nuclei is opening the way to understand and clarify the properties of many nuclei of interest for nuclear structure physics, nuclear astrophysics and particularly for transmutation of nuclear wastes. The surrogate approach is well-recognized as a potentially very useful method to extract neutron cross sections for low-energy compound-nuclear reactions and to overcome the difficulties related to the target radioactivity. In this work we will assess where we stand on these neutron-capture cross section measurements and how we can achieve the short-lived Minor Actinides nuclei involved in the nuclear fuel cycle. The CENBG collaboration applied the surrogate method to determine the neutron-capture cross section of 233Pa (T1/2 = 27 d. The 233Pa (n,γ cross section is then deduced from the measured gamma decay probability of 234Pa compound nucleus formed via the surrogate 232Th(3He,p reaction channel. The obtained cross section data, covering the neutron energy range 0.1 to 1 MeV, have been compared with the predictions of the Hauser-Feshbach statistical model. The importance of establishing benchmarks is stressed for the minor actinides region. However, the lack of desired targets led us to propose recently the 174Yb (3He,pγ reaction as a surrogate reaction for the (n,γ predetermined benchmark cross section of 175Lu. An overview of the experimental setup combining gamma ray detectors such as Ge and C6D6 in coincidence with light charged particles ΔE-E Telescopes will be presented and preliminary results will be discussed.

  7. Undergraduate experiment to find nuclear sizes by measuring total cross sections for fast neutrons

    CERN Document Server

    Minor, T C; Montgomery, H E; Okun, L M; Fowler, J L

    1969-01-01

    Pu- alpha -Be neutron sources, now available in many college laboratories, used with stilbene crystal detectors and proper circuits for neutron-gamma discrimination, permit students to measure fast-neutron total cross sections for a number of easily obtained samples. From these measurements they may calculate the size of nuclei and, using elements covering a wide range of the periodic table, demonstrate the constant density of nuclear matter.

  8. Program POD. A computer code to calculate cross sections for neutron-induced nuclear reactions

    International Nuclear Information System (INIS)

    A computer code, POD, was developed for neutron-induced nuclear data evaluations. This program is based on four theoretical models, (1) the optical model to calculate shape-elastic scattering and reaction cross sections, (2) the distorted wave Born approximation to calculate neutron inelastic scattering cross sections, (3) the preequilibrium model, and (4) the multi-step statistical model. With this program, cross sections can be calculated for reactions (n, γ), (n, n'), (n, p), (n, α), (n, d), (n, t), (n, 3He), (n, 2n), (n, np), (n, nα), (n, nd), and (n, 3n) in the neutron energy range above the resonance region to 20 MeV. The computational methods and input parameters are explained in this report, with sample inputs and outputs. (author)

  9. Fast-neutron total and scattering cross sections of sup 58 Ni and nuclear models

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F. (Argonne National Lab., IL (United States)); Chiba, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

    1991-07-01

    The neutron total cross sections of {sup 58}Ni were measured from {approx} 1 to > 10 MeV using white-source techniques. Differential neutron elastic-scattering cross sections were measured from {approx} 4.5 to 10 MeV at {approx} 0.5 MeV intervals with {ge} 75 differential values per distribution. Differential neutron inelastic-scattering cross sections were measured, corresponding to fourteen levels with excitations up to 4.8 MeV. The measured results, combined with relevant values available in the literature, were interpreted in terms of optical-statistical and coupled-channels model using both vibrational and rotational coupling schemes. The physical implications of the experimental results nd their interpretation are discussed in the contexts of optical-statistical, dispersive-optical, and coupled-channels models. 61 refs.

  10. Amino acids analysis by total neutron cross-sections determinations: part V

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante L.; Ferreira, Francisco de O., E-mail: dante@ien.gov.br, E-mail: fferreira@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da, E-mail: helionutro@hotmail.com [Universidade Federal do Rio de Janeiro (IPPMG/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pediatria

    2013-07-01

    Total neutron cross-sections of twenty essential and non-essential amino acids to human were determined using crystal spectrometer installed on the Argonauta reactor of IEN (Instituto de Engenharia Nuclear (CNEN-RJ) and compared with data generated by parceling and grouping methodologies developed at this institution. For each amino acid was calculated the respective neutron cross-section by molecular structure, conformation and chemistry analysis. The results obtained for eighteen of twenty amino acids confirm the specifications and product formulations indicated by manufactures. These initial results allow to build a neutron cross-sections database as part of quality control of the amino supplied to hospitals for production of nutriments for parenteral or enteral formulations used in critical patients dependent on artificial feed, and for application in future studies of structure and dynamics for more complex molecules, including proteins, enzymes, fatty acids, membranes, organelles and other cell components. (author)

  11. Study of elastic and inelastic neutron cross-sections using time of flight technique

    International Nuclear Information System (INIS)

    High precision neutron scattering data has become increasingly important in the development of nuclear reactors and accelerator systems, astrophysics and space system design, radiation therapy and isotope production, and for shielding considerations. Previous evaluations of the neutron cross-section standards were completed in 1987 and disseminated as NEANDC/INDC and other databases. R-matrix model fits for the light elements and non-model least-squares fits for the heavy elements were the basis of the combined fits for all of the data. Some important reactions and constants are not considered standards, but assist greatly in the determination of the standard cross-sections and reduce their uncertainties. The focus of the present work is to measure elastic and inelastic neutron differential scattering cross-sections for 23Na using Time of Flight Technique for a range of energies with a high accuracy level

  12. Measurement of reaction cross sections of {sup 129}I induced by DT neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan). Faculty of Engineering

    1997-03-01

    The cross sections were measured for the {sup 129}I(n,2n){sup 128}I and {sup 129}I(n,{gamma}){sup 130}I reactions by DT neutrons, at OKTAVIAN facility of Osaka University, Japan. The foil activation method was used in the measurement. The sample was a sealed source of {sup 129}I, which was covered with a Cd foil. The irradiations were performed for 75 minutes to obtain the cross section of reaction producing {sup 128}I (T{sub 1/2}=24.99m) and 22 hours for the {sup 130}I (T{sub 1/2}=12.36h), respectively. The gamma-rays emitted from the irradiated sample were measured with a high purity Ge detector. The measured cross sections of {sup 129}I(n,2n){sup 128}I and {sup 129}I(n,{gamma}){sup 130}I reactions were 0.92{+-}0.11 barn and 0.013{+-}0.002 barn, respectively. For the {sup 129}I(n,2n){sup 128}I reaction, the evaluation of JENDL-3.2 overestimates cross section about 60% to the experimental result. However, especially for the {sup 129}I(n,{gamma}) reaction, the measured cross section may include the contribution from the neutrons in MeV region as well as epithermal ones. Also, the obtained cross section of the {sup 129}I(n,{gamma}){sup 130}I reaction was evaluated as an effective production cross section of {sup 130}I including {sup 129}I(n,{gamma}){sup 130m}I reaction. In order to remove the contribution from the epithermal and MeV region neutrons. A new method was proposed for the measurement of (n,{gamma}) reaction cross section. (author)

  13. Study on target spallation reaction cross sections induced by high energy neutrons and heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Takashi [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center

    1996-03-01

    The target spallation reaction cross sections of neutrons and heavy ions which have not been observed are determined in this paper. The object of this work is to make clear the differences between the spallation reaction cross section of neutron and that of proton by comparing the obtained value of neutron with the known value of proton. To this end, the quasi monochromatic neutron field of 20{approx}50 MeV was developed in 4 cyclotrons, INS, CYRIC, TIARA and RIKEN. The nuclear spallation reaction cross sections of C, Al and Bi were measured in the above field and the distribution of nuclear spallation reaction products in Cu determined by C ion beam of HIMAC. {sup 12}C(n,2n){sup 11}C reaction cross section shows the maximum value of about 20 mb at near 40{approx}50 MeV and then the value gradually decreased to 10 mb. The cross sections of {sup 209}Bi(n,Xn) are shown. The distribution of {sup 61}Cu is lower at the entrance and higher in the depth. (S.Y.)

  14. Cross section model and scattering law of liquid water for design of a cold neutron source

    International Nuclear Information System (INIS)

    A cross section model for cold neutron scattering in light water is developed, which describes various molecular motions inherent to hydrogen-bonded water molecules especially in terms of jump- and rotational-diffusion processes. Inter- and intra-molecular vibrations are also included. A systematic analysis is performed of a velocity autocorrelation function, a generalized frequency distribution and double-differential and total cross sections. Good agreement with the results of computer molecular dynamics and neutron scattering experiments is found. A wide range of cross section evaluation for neutron energies from 0.1 μeV to 10 eV and liquid temperatures between the melting and boiling points is performed. This permits us to generate such low-energy neutron cross section libraries as group constants set and scattering law for ultra-cold, very-cold, cold and thermal neutrons. Together with the libraries for liquid 4He, H2, D2 and solid and liquid CH4, a powerful tool for design of an advanced low-energy neutron source is now ready for use. (author)

  15. Neutron cross section covariances in the resonance region: 52Cr, 56Fe, 58Ni

    Energy Technology Data Exchange (ETDEWEB)

    Oblozinsky, P.; Cho, Y.-S.; Mattoon, C.M.; Mughabghab, S.F.

    2010-08-03

    We evaluated covariances for neutron capture and elastic scattering cross sections on major structural materials, {sup 52}Cr, {sup 56}Fe and {sup 58}Ni, in the resonance region which extends beyond 800 keV for each of them. Use was made of the recently developed covariance formalism based on kernel approximation along with data in the Atlas of Neutron Resonances. The data of most interest for AFCI applications, elastic scattering cross section uncertainties at energies above about few hundred keV, are on the level of about 12% for {sup 52}Cr, 7-8% for {sup 56}Fe and 5-6% for {sup 58}Ni.

  16. Study for determining the correction parameters in neutron capture cross section measurement

    International Nuclear Information System (INIS)

    The aim of this study was to determine correction parameters to improve the accuracy in measurements of the neutron capture cross-section on filtered neutron beams at Dalat nuclear research reactor. Computer codes to calculate these factors for effect of resonance capture at low energy background, multi scattering, and shelf shielding have been developed based on the methods of Monte - Carlo, Neutron transmission and Unfolding. The calculated and experimental results of neutron background spectra for 53.9 keV and 148.3 keV filtered neutron beams and the correction factors for nuclei of 197Au, 139La, 191Ir, 193Ir, and 152Sm are reported. (author)

  17. Measurement of the effective cross section of a 1/v absorber for diffracted polychromatic neutron beam

    International Nuclear Information System (INIS)

    The effective velocity and temperature for the neutron beam of the SNU-KAERI PGAA facility are determined by measuring the prompt γ-ray spectra for thin and thick 10B samples. Both the neutron flux and the γ-ray detection efficiency were set at minimum due to high neutron capture rate for the thick sample. The effective absorption cross section of 10B is obtained from the ratio of 10B peak count rates in both the spectra. The effective velocity and temperature of the neutron beam determined from the effective cross section are 2117 ± 21 m/s and 269 ± 5 K, respectively. These results are consistent with the values calculated from the neutron spectrum in 4%

  18. Average Neutron Total Cross Sections in the Unresolved Energy Range From ORELA High Resolutio Transmission Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H

    2004-05-27

    Average values of the neutron total cross sections of {sup 233}U, {sup 235}U, {sup 238}U, and {sup 239}Pu have been obtained in the unresolved resonance energy range from high-resolution transmission measurements performed at ORELA in the past two decades. The cross sections were generated by correcting the effective total cross sections for the self-shielding effects due to the resonance structure of the data. The self-shielding factors were found by calculating the effective and true cross sections with the computer code SAMMY for the same Doppler and resolution conditions as for the transmission measurements, using an appropriate set of resonance parameters. Our results are compared to results of previous measurements and to the current ENDF/B-VI data.

  19. Empirical Fit to Inelastic Electron-Deuteron and Electron-Neutron Resonance Region Transverse Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Peter Bosted; M. E. Christy

    2007-11-08

    An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic range of four-momentum transfer $0 \\le Q^2<10$ GeV$^2$ and final state invariant mass $1.2<3$ GeV. The deuteron fit relies on a fit of the ratio $R_p$ of longitudinal to transverse cross sections for the proton, and the assumption $R_p=R_n$. The underlying fit parameters describe the average cross section for proton and neutron, with a plane-wave impulse approximation (PWIA) used to fit to the deuteron data. Pseudo-data from MAID 2007 were used to constrain the average nucleon cross sections for $W<1.2$ GeV. The mean deviation of data from the fit is 3\\%, with less than 5\\% of the data points deviating from the fit by more than 10\\%.

  20. Thermal neutron capture cross sections for 16,171,18O and 2H

    Science.gov (United States)

    Firestone, R. B.; Revay, Zs.

    2016-04-01

    Thermal neutron capture γ -ray spectra for 16,17,18O and 2H have been measured with guided cold neutron beams from the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) reactor and the Budapest Research Reactor (BRR) on natural and O,1817 enriched D2O targets. Complete neutron capture γ -ray decay schemes for the 16,17,18O(n ,γ ) reactions were measured. Absolute transition probabilities were determined for each reaction by a least-squares fit of the γ -ray intensities to the decay schemes after accounting for the contribution from internal conversion. The transition probability for the 870.76-keV γ ray from 16O(n ,γ ) was measured as Pγ(871 )=96.6 ±0.5 % and the thermal neutron cross section for this γ ray was determined as 0.164 ±0.003 mb by internal standardization with multiple targets containing oxygen and stoichiometric quantities of hydrogen, nitrogen, and carbon whose γ -ray cross sections were previously standardized. The γ -ray cross sections for the O,1817(n ,γ ) and 2H(n ,γ ) reactions were then determined relative to the 870.76-keV γ -ray cross section after accounting for the isotopic abundances in the targets. We determined the following total radiative thermal neutron cross sections for each isotope from the γ -ray cross sections and transition probabilities; σ0(16O )=0.170 ±0.003 mb; σ0(17O )=0.67 ±0.07 mb; σ0(18O )=0.141 ±0.006 mb; and σ0(2H )=0.489 ±0.006 mb.

  1. Removal cross sections and total mass attenuation coefficients of fast neutrons and gamma rays for steel

    International Nuclear Information System (INIS)

    The present work deals with the study of the attenuation properties and determination of the cross sections of fast neutrons and gamma rays for structure steel used in different applications in nuclear power plants, particle accelerators, research reactors and different radiation attenuation fields. Investigation has been performed by measuring the transmitted fast neutron and gamma ray spectra behind cylindrical samples of steel (ρ=7.87 gem-3) of different thicknesses. A reactor collimated beam and neutron - gamma spectrometer with stiblbene scintillator were used for measurements. The pluse shape disriminate technique based on zero cross over method was used to discriminate between neutron and gamma ray pulses. Effective removal cross-section (σR) and total mass attenuation coefficient (μ) of neureons and gamma rays have been achieved using the attenuation relations. Microscopic removal cross sections σ98 and mass removal cross sections σR/ρ of fast neutrons have been evaluated based on measured results and definite energies. Also, total mass attenuation coefficients (μ/σ) of gamma rays have been evalusted and calculated using measured results and XCOM code respectively. Comparison between measured and calculated results shows a resonable agreement between the two

  2. Neutron-Induced Fission Cross Section Measurements for Full Suite of Uranium Isotopes

    Science.gov (United States)

    Laptev, Alexander; Tovesson, Fredrik; Hill, Tony

    2010-11-01

    A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). The incident neutron energy range spans energies from sub-thermal energies up to 200 MeV by measuring both the Lujan Center and the Weapons Neutron Research center (WNR). Conventional parallel-plate fission ionization chambers with actinide deposited foils are used as a fission detector. The time-of-flight method is implemented to measure neutron energy. Counting rate ratio from investigated and standard U-235 foils is translated into fission cross section ratio. Different methods of normalization for measured ratio are employed, namely, using of actinide deposit thicknesses, normalization to evaluated data, etc. Finally, ratios are converted to cross sections based on the standard U-235 fission cross section data file. Preliminary data for newly investigated isotopes U-236 and U-234 will be reported. Those new data complete a full suite of Uranium isotopes, which were investigated with presented experimental approach. When analysis of the new measured data will is completed, data will be delivered to evaluators. Having data for full set of Uranium isotopes will increase theoretical modeling capabilities and make new data evaluations much more reliable.

  3. Neutron capture cross section of $^{90}$Zr Bottleneck in the s-process reaction flow

    CERN Document Server

    Tagliente, G; Milazzo, P M; Moreau, C; Aerts, G; Abbondanno, U; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Bečvář, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Köhler, P; Kossionides, E; Krtička, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Santos, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M, C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2008-01-01

    The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. The small cross section of the neutron magic nucleus 90Zr, which accounts for more than 50% of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an important component of the structural materials used in traditional and advanced nuclear reactors. The (n,γ) cross section has been measured at CERN, using the n_TOF spallation neutron source. In total, 45 resonances could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the high resolution and low backgrounds at n_TOF. On average, the Γγ widths obtained in resonance analyses with the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the Maxwellian averaged cross section f...

  4. Fast-neutron total and scattering cross sections of Cr, Fe and 60Ni

    International Nuclear Information System (INIS)

    Neutron total cross sections are measured with broad resolutions (50 to 100 keV) from approx. = 1.0 to 4.5 MeV at intervals of less than or equal to 50 keV and to accuracies of approx. = 1% using a variety of sample thicknesses. Differential elastic-scattering cross sections are measured at greater than or equal to 10 scattering angles distributed between 20 to 160 deg. from approx. = 1.5 to 4.0 MeV at intervals of less than or equal to 50 keV. Angle-integrated elastic scattering cross sections are deduced from the measured values to accuracies greater than or equal to 5%. Inelastic-neutron-scattering cross sections are determined up to incident neutron energies of 4.0 MeV, at scattering angles distributed between 20 to 160 deg., and for 5 observed excitations in Cr, for 7 in Fe and for 6 in 60Ni. The experimental results are discussed in terms of conventional optical-statistical models with attention to cross section fluctuations and in the context of direct-scattering processes. The experimental and calculational results are compared with the corresponding evaluated quantities given in the ENDF/B file with attention to regions of agreement and inconsistency. 14 references

  5. Energy-averaged neutron cross sections of fast-reactor structural materials

    International Nuclear Information System (INIS)

    The status of energy-averaged cross sections of fast-reactor structural materials is outlined with emphasis on U.S. data programs in the neutron-energy range 1-10 MeV. Areas of outstanding accomplishment and significant uncertainty are noted with recommendations for future efforts. Attention is primarily given to the main constituents of stainless steel (e.g., Fe, Ni, and Cr) and, secondarily, to alternate structural materials (e.g., V, Ti, Nb, Mo, Zr). Generally, the mass regions of interest are A approximately 50 to 60 and A approximately 90 to 100. Neutron total and elastic-scattering cross sections are discussed with the implication on the non-elastic-cross sections. Cross sections governing discrete-inelastic-neutron-energy transfers are examined in detail. Cross sections for the reactions (n;p), (n;n',p), (n;α), (n;n',α) and (n;2n') are reviewed in the context of fast-reactor performance and/or diagnostics. The primary orientation of the discussion is experimental with some additional attention to the applications of theory, the problems of evaluation and the data sensitivity of representative fast-reactor systems

  6. Amino acids analysis by neutron cross-section techniques - Part III

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante L.; Ferreira, Francisco de O. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: dante@ien.gov.br; Rocha, Helio F. da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Puericultura e Pediatria Martagao Gesteira (IPPMG)]. E-mail: hrocha@gbl.com.br

    2007-07-01

    To continue the work initiated some time ago, about neutron cross section determinations of amino acids, which are directly encoded for protein synthesis by the standard genetic code, we are now measuring six more amino acids samples, with more complex structures to complete the project. All these amino acids are used in enteral and parenteral administration in hospital patients for nutritional applications. The present calculations are a little more difficult because of a new proceeding introduced in the method to explain its molecular structures and obtain its molecular formulae. These amino acids present different radical and elements related to the compounds available in the previous works. Each one, present different structure and freedom grade of movement related to the types of radicals linked in the repetitive structure. In that way, neutron cross section values change with the chemical binding intensities. These details obligate us to search new compounds with new molecular structures to obtain neutron cross sections for posterior comparison , meanly compounds including nitrogen, sulfur and oxygen groups linked to hydrogen atoms. At this time, individual amino acid samples of proline, glutamine, lysine, arginine, histidine, and glutamic acid were measured. It was used the neutron crystal spectrometer installed at the J-9 irradiation channel of the 1 kW Argonauta Reactor of the Instituto de Engenharia Nuclear (IEN). Gold and D{sub 2}O high purity samples were used for the experimental system calibration. Neutron cross section values were calculated from chemical composition, conformation and molecular structure analysis of the materials. Literature data were manipulated by parceling and grouping neutron cross-sections. (author)

  7. Neutron cross sections of 187Os and their analysis with accounting of possible correlation of elastic and inelastic scattering channels

    International Nuclear Information System (INIS)

    Averaged total cross sections in the 1.9-144 keV energy region and neutron elastic and inelastic scattering cross sections at 24.4 keV neutron energy have been measured for 187Os. Experimental data analysis for 187Os neutron cross sections in the E 187 averaged resonance parameters have been determined. The best experimental data approximation was obtained for the correlation coeffient ρ = 0.65 for elastic and inelastic amplitudes

  8. Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA

    CERN Document Server

    Breitweg, J; Derrick, Malcolm; Krakauer, D A; Magill, S; Musgrave, B; Pellegrino, A; Repond, J; Stanek, R; Yoshida, R; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Levi, G; Margotti, A; Massam, Thomas; Nania, R; Palmonari, F; Pesci, A; Bornheim, A; Brock, I; Coboken, K; Crittenden, James Arthur; Deffner, R; Heinloth, K; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kerger, R; Paul, E; Rautenberg, J; Schnurbusch, H; Stifutkin, A; Tandler, J; Voss, K C; Weber, A; Wieber, H; Bailey, D S; Barret, O; Brook, N H; Foster, B; Heath, G P; Heath, H F; Rodrigues, E; Scott, J; Tapper, R J; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Jeoung, H Y; Kim, J Y; Lee, J H; Lim, I T; Ma, K J; Pac, M Y; Caldwell, A; Liu, W; Liu, X; Mellado, B; Paganis, S; Sampson, S; Schmidke, W B; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Klimek, K H; Olkiewicz, K; Piotrzkowski, K; Stopa, P; Zawiejski, L; Bednarek, B; Jelen, K; Kisielewska, D; Kowal, A M; Kowalski, T; Przybycien, M B; Suszycki, L; Szuba, D; Bauerdick, L A T; Behrens, U; Bienlein, J K; Borras, K; Chiochia, V; Dannheim, D; Desler, K; Drews, G; Fox-Murphy, A; Fricke, U; Göbel, F; Goers, S; Göttlicher, P; Graciani, R; Haas, T; Hain, W; Hartner, G F; Hebbel, K; Hillert, S; Koch, W; Kötz, U; Kowalski, H; Labes, H; Löhr, B; Mankel, R; Martens, J; Martínez, M; Milite, M; Moritz, M; Notz, D; Petrucci, M C; Polini, A; Rohde, M; Savin, A A; Schneekloth, U; Selonke, F; Sievers, M; Stonjek, S; Wolf, G; Wollmer, U; Youngman, C; Zeuner, W; Coldewey, C; López-Duran-Viani, A; Meyer, A; Schlenstedt, S; Straub, P B; Barbagli, G; Gallo, E; Parenti, A; Pelfer, P G; Bamberger, Andreas; Benen, A; Coppola, N; Eisenhardt, S; Markun, P; Raach, H; Wölfle, S; Bussey, Peter J; Bell, M; Doyle, A T; Glasman, C; Lee, S W; Lupi, A; MacDonald, N; McCance, G J; Saxon, D H; Sinclair, L E; Skillicorn, Ian O; Waugh, R; Bohnet, I; Gendner, N; Holm, U; Meyer-Larsen, A; Salehi, H; Wick, K; Carli, T; Garfagnini, A; Gialas, I; Gladilin, L K; Kcira, D; Klanner, Robert; Lohrmann, E; Goncalo, R; Long, K R; Miller, D B; Tapper, A D; Walker, R; Cloth, P; Filges, D; Ishii, T; Kuze, M; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Ahn, S H; Lee, S B; Park, S K; Lim, H; Son, D; Barreiro, F; García, G; González, O; Labarga, L; Del Peso, J; Redondo, I; Terron, J; Vázquez, M E; Barbi, M S; Corriveau, F; Hanna, D S; Ochs, A; Padhi, S; Stairs, D G; Wing, M; Tsurugai, T; Antonov, A; Bashkirov, V; Danilov, M V; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V V; Suchkov, S; Dementev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korotkova, N A; Korzhavina, I A; Kuzmin, V A; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Solomin, A N; Vlasov, N N; Zotkin, S A; Bokel, C; Botje, M; Brümmer, N; Engelen, J; Grijpink, S; Koffeman, E; Kooijman, P M; Schagen, S; Van Sighem, A; Tassi, E; Tiecke, H G; Tuning, N; Velthuis, J J; Vossebeld, Joost Herman; Wiggers, L; De Wolf, E; Bylsma, B; Durkin, L S; Gilmore, J; Ginsburg, C M; Kim, C L; Ling, T Y; Boogert, S; Cooper-Sarkar, A M; Devenish, R C E; Grosse-Knetter, J; Matsushita, T; Ruske, O; Sutton, M R; Walczak, R; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; Dusini, S; Limentani, S; Longhin, A; Posocco, M; Stanco, L; Turcato, M; Adamczyk, L; Iannotti, L; Oh, B Y; Okrasinski, J R; Saull, P R B; Toothacker, W S; Whitmore, J J; Iga, Y; D'Agostini, Giulio; Marini, G; Nigro, A; Cormack, C; Hart, J C; McCubbin, N A; Shah, T P; Epperson, D E; Heusch, C A; Sadrozinski, H F W; Seiden, A; Wichmann, R; Williams, D C

    2000-01-01

    Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e^+ + p --> e^+ + n + jet + jet + X_r have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb^{-1}. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies E^{jet}_T > 6 GeV, neutron energy E_n > 400 GeV, and neutron production angle theta_n < 0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model.

  9. Neutron cross section measurements at n-TOF for ADS related studies

    CERN Document Server

    Mastinu, P F; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, P A; Audouin, L; Badurek, G; Bustreo, N; Aumann, P; Beva, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Segura, M E; Ferrant, L; Ferrari, A; Ferreira-Marques, R; itzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Guerrero, C; Gonçalves, I; Gallino, R; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Käppeler, F K; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Massimi, C; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescherand, M; Wisshak, K

    2006-01-01

    A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.

  10. Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA

    International Nuclear Information System (INIS)

    Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e++p→e++n+jet+jet+Xr have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies ETjet>6 GeV, neutron energy En>400 GeV, and neutron production angle θn<0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model

  11. Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Breitweg, J.; Chekanov, S.; Derrick, M.; Krakauer, D.; Magill, S.; Musgrave, B.; Pellegrino, A.; Repond, J.; Stanek, R.; Yoshida, R.; Mattingly, M.C.K.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; Pesci, A.; Sartorelli, G.; Zichichi, A.; Amelung, C.; Bornheim, A.; Brock, I.; Coboeken, K.; Crittenden, J.; Deffner, R.; Hartmann, H.; Heinloth, K.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kappes, A.; Katz, U.F.; Kerger, R.; Paul, E.; Rautenberg, J.; Schnurbusch, H.; Stifutkin, A.; Tandler, J.; Voss, K.C.; Weber, A.; Wieber, H.; Bailey, D.S.; Barret, O.; Brook, N.H.; Foster, B. E-mail: b.foster@bristol.ac.uk; Heath, G.P.; Heath, H.F.; Rodrigues, E.; Scott, J.; Tapper, R.J.; Capua, M.; Schioppa, M.; Susinno, G.; Jeoung, H.Y.; Kim, J.Y.; Lee, J.H.; Lim, I.T.; Ma, K.J.; Pac, M.Y.; Caldwell, A.; Liu, W.; Liu, X.; Mellado, B.; Paganis, S.; Sampson, S.; Schmidke, W.B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Klimek, K.; Olkiewicz, K.; Piotrzkowski, K.; Przybycien, M.B.; Stopa, P.; Zawiejski, L.; Bednarek, B.; Jelen, K.; Kisielewska, D.; Kowal, A.M.; Kowalski, T.; Przybycien, M.; Rulikowska-Zarebska, E.; Suszycki, L.; Szuba, D.; Kotanski, A.; Bauerdick, L.A.T.; Behrens, U.; Bienlein, J.K.; Borras, K.; Chiochia, V.; Dannheim, D.; Desler, K.; Drews, G.; Fox-Murphy, A.; Fricke, U.; Goebel, F.; Goers, S.; Goettlicher, P.; Graciani, R.; Haas, T.; Hain, W.; Hartner, G.F.; Hebbel, K.; Hillert, S.; Koch, W.; Koetz, U.; Kowalski, H.; Labes, H.; Loehr, B.; Mankel, R.; Martens, J.; Martinez, M.; Milite, M.; Moritz, M.; Notz, D.; Petrucci, M.C.; Polini, A.; Rohde, M.; Savin, A.A.; Schneekloth, U.; Selonke, F.; Sievers, M.; Stonjek, S.; Wolf, G.; Wollmer, U.; Youngman, C.; Zeuner, W.; Coldewey, C.; Lopez-Duran Viani, A.; Meyer, A.; Schlenstedt, S.[and others

    2001-02-26

    Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e{sup +}+p{yields}e{sup +}+n+jet+jet+X{sub r} have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb{sup -1}. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies E{sub T}{sup jet}>6 GeV, neutron energy E{sub n}>400 GeV, and neutron production angle {theta}{sub n}<0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model.

  12. Neutron secondary-particle production cross sections and their incorporation into Monte-Carlo transport codes

    International Nuclear Information System (INIS)

    Realistic simulations of the passage of fast neutrons through tissue require a large quantity of cross-sectional data. What are needed are differential (in particle type, energy and angle) cross sections. A computer code is described which produces such spectra for neutrons above ∼14 MeV incident on light nuclei such as carbon and oxygen. Comparisons have been made with experimental measurements of double-differential secondary charged-particle production on carbon and oxygen at energies from 27 to 60 MeV; they indicate that the model is adequate in this energy range. In order to utilize fully the results of these calculations, they should be incorporated into a neutron transport code. This requires defining a generalized format for describing charged-particle production, putting the calculated results in this format, interfacing the neutron transport code with these data, and charged-particle transport. The design and development of such a program is described. 13 refs., 3 figs

  13. Neutron Capture Cross Sections of Zr and La: Probing Neutron Exposure and Neutron Flux in Red Giant Stars

    CERN Multimedia

    Kitis, G; Wiescher, M; Dahlfors, M; Soares, J

    2002-01-01

    We propose to measure the neutron capture cross sections of $^{139}$La, of $^{93}$Zr (t$_{1/2}$)=1.5 10$^{6}$ yr), and of all the stable Zr isotopes at n_TOF. The aim of these measurements is to improve the accuracy of existing results by at least a factor of three in order to meet the quality required for using the s-process nucleosynthesis as a diagnostic tool for neutron exposure and neutron flux during the He burning stages of stellar evolution. Combining these results with a wealth of recent information coming from high-resolution stellar spectroscopy and from the detailed analysis of presolar dust grains will shed new light on the chemical history of the universe. The investigated cross sections are also needed for technological applications, in particular since $^{93}$Zr is one of the major long-lived fission products.

  14. Neutron-scattering cross section of the S=1/2 Heisenberg triangular antiferromagnet

    DEFF Research Database (Denmark)

    Lefmann, K.; Hedegård, P.

    1994-01-01

    In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with long...

  15. HADES. A computer code for fast neutron cross section from the Optical Model

    International Nuclear Information System (INIS)

    A FORTRAN V computer code for UNIVAC 1108/6 using a local Optical Model with spin-orbit interaction is described. The code calculates fast neutron cross sections, angular distribution, and Legendre moments for heavy and intermediate spherical nuclei. It allows for the possibility of automatic variation of potential parameters for experimental data fitting. (Author) 55 refs

  16. Contribution to the study of the unresolved resonance range of the neutrons cross sections

    International Nuclear Information System (INIS)

    This document presents the statistical description of neutron cross sections in the unresolved resonance range. The modeling of the total cross section and of the 'shape - elastic' cross section is based on the 'average R-Matrix' formalism. The partial cross sections describing the radiative capture, elastic scattering, inelastic scattering and fission process are calculated using the Hauser-Feshbach formalism with width fluctuation corrections. In the unresolved resonance range, these models depend on the average resonance parameters (neutron strength function Sc, mean level spacing Dc, average partial reaction widths Γc, channel radius ac, effective radius R' and distant level parameter R-barc∞). The codes (NJOY, CALENDF...) dedicated to the processing of nuclear data libraries (JEFF, ENDF/B, JENDL, CENDL, BROND... ) use the average parameters to take into account the self-shielding phenomenon for the simulation of the neutron transport in Monte-Carlo (MCNP, TRIPOLI... ) and deterministic (APOLLO, ERANOS...) codes. The evaluation work consists in establishing a consistent set of average parameters as a function of the total angular momentum J of the system and of the orbital moment of the incident neutron l. The work presented in this paper aims to describe the links between the S-Matrix and the 'average R-Matrix' formalism for the calculation of Sc, R-barc∞, ac and R'. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-08

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

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

    International Nuclear Information System (INIS)

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

  19. The CERN n_TOF Facility: Neutron Beams Performances for Cross Section Measurements

    CERN Document Server

    Chiaveri, E; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Gurusamy, P; Hernández-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P F; Mastromarco, M; Meaze, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Roman, F; Rubbia, C; Sabaté-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T; Žugec, P

    2014-01-01

    This paper presents the characteristics of the existing CERN n\\_TOF neutron beam facility (n\\_TOF-EAR1 with a flight path of 185 meters) and the future one (n\\_TOF EAR-2 with a flight path of 19 meters), which will operate in parallel from Summer 2014. The new neutron beam will provide a 25 times higher neutron flux delivered in 10 times shorter neutron pulses, thus offering more powerful capabilities for measuring small mass, low cross section and/or high activity samples.

  20. Production of a 44 Ti target and its cross section of thermal neutron capture

    International Nuclear Information System (INIS)

    A study of the production of a 44 Ti target was carried out aiming the determination of its thermal neutron capture cross-section. With this purpose, the cross-section of the reaction 45 Sc(p,2 n) 44 Ti was determined in the energies 16-, 18-, 20-22- and 45 MeV. The cross-section of the reactions (p,n) 45 Ti, (p,pn) 44m Sc, (p,pn) 44g Sc and (p,p2n)43 Sc were also measured. The results in the low energy region are in good agreement with a previous work by McGee et al. On the other hand, the cross-section at 45 MeV is different from McGee's result and indicates the existence of an abnormal behavior of the excitation function at higher energies. Furthermore, a radiochemical separation method was developed in order to eliminate Sc from the 44 Ti target which was irradiated with neutrons. It was possible to determine an upper limit for the cross-section of the reaction 44 Ti (n, γ) of 4 x 103 b. At last, it is presented a discussion of the results obtained and their possible astrophysical implications. (author)

  1. Evaluation of neutron cross sections for the Pd isotopes (RCN-3 data library)

    International Nuclear Information System (INIS)

    The evaluation procedure to obtain neutron cross sections of 102Pd, 104Pd, 105Pd, 106Pd, 107Pd, 108Pd and 110Pd for inclusion in the RCN-3 data library of fission-product cross sections is described. The new evaluation takes into account the results of recent differential and integral data. Most of the adopted resolved resonance parameters have been taken from the new CBNM measurements; for 107Pd the recent RPI data have been used. These resolved resonance parameters have been extensively analysed to obtain average values for the level spacing, capture width and neutron s- and p-wave strength functions. The systematics of the single-particle level-density parameter α and the capture width show significant odd-even effects. Optical-model and statistical-model calculations have been performed to obtain cross sections of reactions at energies from 1 meV to 15 MeV. The results for the capture cross sections based upon the analysed average resonance parameters turned out to be systematically lower than the ORELA average capture data and also lower than indicated by the most integral STEK data (except for 105Pd). As a compromise we have performed adjustments to increase the calculated fast capture cross sections for 104Pd, 106Pd and 108Pd

  2. New upper bound on the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    CERN Document Server

    Grammer, K B; Barrón-Palos, L; Blyth, D; Bowman, J D; Calarco, J; Crawford, C; Craycraft, K; Evans, D; Fomin, N; Fry, J; Gericke, M; Gillis, R C; Greene, G L; Hamblen, J; Hayes, C; Kucuker, S; Mahurin, R; Maldonado-Velázquez, M; Martin, E; McCrea, M; Mueller, P E; Musgrave, M; Nann, H; Penttilä, S I; Snow, W M; Tang, Z; Wilburn, W S

    2014-01-01

    The scattering of slow neutron beams provides unique, non-destructive, quantitative information on the structure and dynamics of materials of interest in physics, chemistry, materials science, biology, geology, and other fields. Liquid hydrogen is a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. In particular the rapid drop of the slow neutron scattering cross section of liquid parahydrogen below 15 meV, which renders the moderator volume transparent to the neutron energies of most interest for scattering studies, is therefore especially interesting and important. We have placed an upper bound on the total cross section and the scattering cross section for slow neutrons with energies between 0.43 meV and 16.1 meV on liquid hydrogen at 15.6 K using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge Nati...

  3. Neutron capture cross section of $^{25}$Mg and its astrophysical implications

    CERN Multimedia

    We propose to measure the neutron capture cross section of the stable $^{25}$Mg isotope. This experiment aims at the improvement of existing results for nuclear astrophysics.The measurement will be carried out under similar conditions as for the Mgexperiment that was completed at n_TOF during 2003. A metal $^{25}$Mg-enriched sample will be used in the proposed experiment instead of a MgO powder sample, which was used in the previous measurement and prevented us to minimize the uncertainty of the measured cross section. This experiment will be part of an ongoing study for a comprehensive discussion of the s-process abundances in massive stars.

  4. Evaluated neutron-induced cross sections for 40Ca from 20 to 40 MeV

    International Nuclear Information System (INIS)

    Nuclear model codes were used to compute cross sections for neutron-induced reactions on 40Ca for incident energies from 20 to 40 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Computed cross sections along with emission spectra for each product were combined into an Evaluated Nuclear Data File (ENDF) using the proposed format for charged-particle reactions. Discussion of the models used, the resulting calculations, and the final evaluated data file are presented

  5. Measurement of resonance self-shielding factors of neutron capture cross section by 238U

    International Nuclear Information System (INIS)

    Resonance self-shielding factors fsub(c) of neutron capture cross section by 238U in the 20-100 keV energy range are measured. The method for determining the fsub(c) factor consists in measuring partial transmission and transmission in the total cross section at different 238U filter thickness. The fsub(c) factor values in the 46.5-100 and 21.5-46.5 keV energy ranges are equal to 0.89+-0.03 and 0.81+-0.04, respectively

  6. Extracting electric dipole breakup cross section of one-neutron halo nuclei from breakup observables

    CERN Document Server

    Yoshida, Kazuki; Minomo, Kosho; Ogata, Kazuyuki

    2014-01-01

    How to extract an electric dipole (E1) breakup cross section \\sigma(E1) from one- neutron removal cross sections measured by using 12C and 208Pb targets, \\sigma_(-1n)^C and \\sigma_(-1n)^Pb, respectively, is discussed. It is shown that within about 5% error, \\sigma(E1) can be obtained by subtracting \\Gamma \\sigma_(-1n)^C from \\sigma_(- 1n)^Pb, as assumed in preceding studies. However, for the reaction of weakly-bound projectiles, the scaling factor \\Gamma is found to be two times as large as that usually adopted. As a result, we obtain 13-20% smaller \\sigma(E1) of 31Ne at 250 MeV/nucleon than extracted in a previous analysis of experimental data. By compiling the values of \\Gamma obtained for several projectiles, \\Gamma=(2.30 +/- 0.41)\\exp(- S_n)+(2.43 +/- 0.21) is obtained, where S_n is the neutron separation energy. The target mass number dependence of the nuclear parts of the one-neutron removal cross section and the elastic breakup cross section is also investigated.

  7. Measurement of Dijet Cross Sections in ep Interactions with a Leading Neutron at HERA

    CERN Document Server

    Andreev, V; Aplin, S; Asmone, A; Babaev, A; Backovic, S; Bähr, J; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baudrand, S; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bracinik, J; Brandt, G; Brisson, V; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Chekelian, V; Contreras, J G; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; Delcourt, B; Demirchyan, R; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dodonov, V; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, W; Essenov, S; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Finke, L; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Fomenko, A; Foresti, I; Formánek, J; Franke, G; Frising, G; Frisson, T; Gabathuler, Erwin; Garutti, E; Gayler, J; Gerhards, R; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Glazov, A; Glushkov, I; Görlich, L; Göttlich, M; Gogitidze, N; Gorbounov, S; Goyon, C; Grab, C; Greenshaw, T; Gregori, M; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Haller, J; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Herrera-Corral, G; Herynek, I; Heuer, R D; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, H; Kapichine, M; Karlsson, M; Katzy, J; Keller, N; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Korbel, V; Kostka, P; Koutouev, R; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Kuckens, J; Landon, M P J; Lange, W; Lastoviicka, T; Laycock, P; Lebedev, A; Leiner, B; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; List, B; Lobodzinska, E; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mohamed, A; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nankov, K; Naroska, Beate; Naumann, J; Naumann, T; Newman, P R; Niebuhr, C B; Nikiforov, A; Nikitin, D K; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perez-Astudillo, D; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Pöschl, R; Portheault, B; Povh, B; Prideaux, P; Raicevic, N; Reimer, P; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rurikova, Z; Rusakov, S V; Salvaire, F; Sankey, D P C; Sauvan, E; Schatzel, S; Scheins, J; Schilling, F P; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schröder, V; Schultz-Coulon, H C; Schwanenberger, C; Sedlak, K; Sefkow, F; Shevyakov, I; Shtarkov, L N; Sirois, Y; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsakov, I; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, M; Usik, A; Utkin, D; Valkár, S; Valkárová, A; Vallée, C; Van Mechelen, P; Van Remortel, N; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Vujicic, B; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Wigmore, C; Winter, G G; Wissing, C; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zimmermann, J; Zohrabyan, H G; Zomer, F

    2005-01-01

    Measurements are reported of the production of dijet events with a leading neutron in ep interactions at HERA. Differential cross sections for photoproduction and deep inelastic scattering are presented as a function of several kinematic variables. Leading order QCD simulation programs are compared with the measurements. Models in which the real or virtual photon interacts with a parton of an exchanged pion are able to describe the data. Next-to-leading order perturbative QCD calculations based on pion exchange are found to be in good agreement with the measured cross sections. The fraction of leading neutron dijet events with respect to all dijet events is also determined. The dijet events with a leading neutron have a lower fraction of resolved photon processes than do the inclusive dijet data.

  8. Neutron capture cross section measurement of $^{151}Sm$ at the CERN neutron Time of Flight Facility (nTOF)

    CERN Document Server

    Abbondanno, U; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, Samuel A; Andrzejewski, J; Badurek, G; Baumann, P; Becvar, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Cortina-Gil, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Durán, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Kölbl, H; Furman, W; Gonçalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Isaev, S; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, Armando; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wissha, K

    2004-01-01

    The measurement of **1**5**1Sm(n, gamma)**1**5**2Sm (samarium) cross section showed improved performance of the new spallation neutron facility. It covered a wide energy range with good resolution, high neutron flux, low backgrounds and a favourable duty factor. The samarium cross section was found to be of great importance for characterizing neutron capture nucleosynthesis in asymptotic giant stars. The combination of these features provided a promising basis for a broad experimental program directed towards application in astrophysics and advanced nuclear technologies. (Edited abstract)

  9. High resolution neutron total and capture cross-sections in separated isotopes of copper (6365Cu)

    International Nuclear Information System (INIS)

    High resolution neutron total and capture cross section measurements have been performed on separated isotopes of copper (6365Cu). Measurements for capture cross section were made from about 1 keV to a few hundreds of keV. The total cross section measurements were made in the energy interval of approximately 10 keV to 150 keV. The resulting capture data have been analyzed by a generalized least square peak fitting computer code in the energy interval of 2.5 keV to 50 keV. Photon strengths are determined using the data up to approximately 250 keV. The resulting total cross section data have been analyzed by area-analysis on the transmission values and by R-matrix multilevel code on cross section values. Average s- and p-wave level spacing and s- and p-wave strength function values are determined. From the resonance parameters thus obtained, by the analysis, statistical distribution is studied for s- and p-wave level spacings and reduced neutron widths. A comparison has been made for adjacent level spacings with the theoretical predictions of level repulsion (of same J/sup π/) by Wigner considering levels with various spin states separately for s-wave resonances where confident spin assignment has been possible. Reduced neutron widths are compared with the Porter-Thomas distribution. Optical model formulated by Feshbach, Porter and Weiskopf describes the neutron-nucleus interaction. A comparison has been made between experimentally determined values of the s- and p-wave strength functions and that obtainable from optical model calculations, thereby determining the appropriate optical model parameters. The experimental arrangement, pertinent theoretical discussion, and the processes of data reduction and the analyses along with the comparison of the previously reported results with the present work are presented in detail

  10. Validation of multigroup neutron cross sections for the Advanced Neutron Source against the FOEHN critical experimental measurements

    International Nuclear Information System (INIS)

    The FOEHN critical experiments were analyzed to validate the use of multigroup cross sections in the design of the Advanced Neutron Source. Eleven critical configurations were evaluated using the KENO, DORT, and VENTURE neutronics codes. Eigenvalue and power density profiles were computed and show very good agreement with measured values

  11. Neutron capture cross-sections of krypton isotopes and their astrophysical implications

    International Nuclear Information System (INIS)

    For the measurement of neutron capture cross sections of noble gases a new experimental technique was developed using high pressure gas targets. By this technique, measurements on five krypton samples with different isotopic composition were performed by which the capture and the total cross sections between 5 and 200 keV were determined in the same experiment with good statistical accuracy. Values of Maxwellian averaged capture cross sections at 30 keV could be derived for the stable isotopes of krypton, as they are required for a quantitative understanding of the s-process of nucleosynthesis. From the systematics of this s-process it was possible to determine the original abundance of krypton in the solar system. The branching of the s-process at Se-79 allowed to determine the temperature of the s-process. A value of kT = 35 keV is adopted by this calculation. (orig.) 891 KBE/orig. 892 HIS

  12. Neutron-induced cross sections of actinides via the surrogate-reaction method

    Directory of Open Access Journals (Sweden)

    Tveten G. M.

    2013-03-01

    Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method for extracting capture cross sections has to be investigated. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutroninduced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. First results are presented and discussed.

  13. Neutron capture cross-section studies of Tellurium isotopes for neutrinoless double beta decay applications

    Science.gov (United States)

    Bhike, Megha; Tornow, Werner

    2014-09-01

    The CUORE detector at Gran Sasso, aimed at searching for neutrinoless double-beta decay of 130Te, employs an array of TeO2 bolometer modules. To understand and identify the contribution of muon and (α,n) induced neutrons to the CUORE background, fast neutron cature cross-section data of the tellurium isotopes 126Te, 128Te and 130Te have been measured with the activation method at eight different energies in the neutron energy range 0.5-7.5 MeV. Plastic pill boxes of diameter 1.6 cm and width 1 cm containing Te were irradiated with mono-energetic neutrons produced via the 3H(p,n)3He and 2H(d,n)3He reactions. The cross-sections were determined relative to the 197Au(n, γ)198Au and 115In(n,n')115m In standard cross sections. The activities of the products were measured using 60% lead-shielded HPGe detectors at TUNL's low background counting facility. The present results are compared with the evaluated data from TENDL-2012, ENDF/B-VII.1, JEFF-3.2 and JENDL-4.0, as well as with literature data.

  14. NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION

    Energy Technology Data Exchange (ETDEWEB)

    OH,S.Y.; CHANG,J.; MUGHABGHAB,S.

    2000-05-11

    Neutron cross section evaluations of the fission-product isotopes, {sup 95}Mo, {sup 99}Tc, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, {sup 141}Nd, {sup 147}Sm, {sup 149}Sm, {sup 150}Sm, {sup 151}Sm, {sup 152}Sm, {sup 153}Eu, {sup 155}Gd, and {sup 157}Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of {sup 155}Gd and {sup 157}Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations.

  15. 252Cf-based thermal-neutron cross-section gauge for interpretation of neutron logs for oil exploration

    International Nuclear Information System (INIS)

    A newly developed neutron absorption cell measures the thermal-neutron absorption cross sections (Σ/sub w/) of formation brines encountered in logging operations. Thermal-neutron decay time logs with pulsed neutron logging systems are important tools of modern oil exploration technology. These logs yield information about oil saturation characteristics of the formation and oil-water contact location, provided the thermal-neutron cross-section behavior of the host formation is known. This cross section is determined to an important degree by that of the formation brine (Σ/sub w/). Presently, Σ/sub w/ is in most cases estimated from the chemically determined salinity of the brine, since actual measurements with a pulsed neutron logging tool are impractical, requiring several hundred gallons of the brine in a large tank. The chemical analyses are typically performed in a laboratory which is remote from the exploration site. With the portable neutron absorption cell, this measurement is made on site on a sample as small as four liters, with a precision of 0.1% in less than 5 minutes. The results of cell analyses on seventeen brine samples from oil fields in the United States and Canada are discussed. The cross sections measured have been compared with cross sections calculated from chemical and atomic absorption analyses. The agreement is within the experimental errors of the chemical analyses in all cases. Importantly, in all cases boron contributed a noticeable amount to the total absorption cross section. This boron contribution is ignored by conventional brine analyses precluding an accurate estimate of oil saturation, especially in the case of expensive log-inject-log measurements of residual oil preceding secondary or tertiary recovery

  16. Model for neutron total cross-section at low energies for nuclear grade graphite

    Energy Technology Data Exchange (ETDEWEB)

    Galván Josa, V.M. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), FaMAF, Universidad Nacional de Córdoba (Argentina); Dawidowski, J., E-mail: javier@cab.cnea.gov.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Comisión Nacional de Enegía Atómica-Universidad Nacional de Cuyo (Argentina); Santisteban, J.R.; Malamud, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Comisión Nacional de Enegía Atómica-Universidad Nacional de Cuyo (Argentina); Oliveira, R.G. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CIQUIBIC, Fac. Cs. Químicas, Universidad Nacional de Córdoba (Argentina)

    2015-04-21

    At subthermal neutron energies, polycrystalline graphite shows a large total cross-section due to small angle scattering processes. In this work, a new methodology to determine pore size distributions through the neutron transmission technique at subthermal energies is proposed and its sensitivity is compared with standard techniques. A simple model based on the form factor for spherical particles, normally used in the Small Angle Neutron Scattering technique, is employed to calculate the contribution of small angle effect to the total scattering cross-section, with the width and center of the radii distributions as free parameters in the model. Small Angle X-ray Scattering experiments were performed to compare results as a means to validate the method. The good agreement reached reveals that the neutron transmission technique is a useful tool to explore small angle scattering effects. This fact can be exploited in situations where large samples must be scanned and it is difficult to investigate them with conventional methods. It also opens the possibility to apply this method in energy-resolved neutron imaging. Also, since subthermal neutron transmission experiments are perfectly feasible in small neutron sources, the present findings open new possibilities to the work done in such kind of facilities.

  17. Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies

    Science.gov (United States)

    Kinoshita, N.; Hayashi, K.; Ueno, S.; Yatsu, Y.; Yokoyama, A.; Takahashi, N.

    2016-02-01

    Background: The p nuclei, which are not produced by neutron capture processes, are present with a typical isotopic abundance of 0.01%-0.3%. Abundance decreases with an increase in atomic number. However, the neutron-magic isotopes of 92Mo and 144Sm exhibit unusually large abundances in comparison. A combination of proton and α -particle capture reactions and neutron emission reactions are key to understanding this issue. Currently, complex network calculations do not have access to much experimental data, and hence require theoretically predicted reaction rates in order to estimate final abundances produced in nucleosynthesis. Purpose: Few experimental cross sections of (p ,γ) reactions on heavy nuclides with mass numbers of 130-150 have been reported. The 144Sm(p ,γ )145Eu reaction is the main destruction pathway for the nucleosynthesis of the 144Sm nuclide. In the present paper, experimental cross sections of the 144Sm(p ,γ )145Eu reaction at a range including astrophysically relevant energies for the p process were determined to compare with theoretical predictions using the Hauser-Feshback statistical model. Methods: The 144Sm was deposited on a high-purity Al foil with the molecular plating method. Stacks consisting of Ta degrader foils, 144Sm targets, and Cu foils used as flux monitors were irradiated with 14.0-MeV proton beams. The 144Sm(p ,γ )145Eu cross sections were determined from the 145Eu activities and the proton fluence estimated from the 65Zn activity in the Cu monitor foil. The proton energies bombarded on each 144Sm target were estimated using srim2013. Results: We determined the 144Sm(p ,γ )145Eu cross sections at proton energies between 2.8 and 7.6 MeV. These energies encompass nucleosynthesis temperatures between 3 and 5 GK. The cross sections at energies higher than 3.8 MeV agreed well with theoretically predicted cross sections using talys using the generalized superfluid (GS) model for level densities. However, calculations using non

  18. RSAP - A Code for Display of Neutron Cross Section Data and SAMMY Fit Results

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.

    2001-02-02

    RSAP is a computer code for display of neutron cross section data and selected SAMMY output. SAMMY is a multilevel R-matrix code for fitting neutron time-of-flight cross-section data using Bayes' method. RSAP, which runs on the Digital Unix Alpha platform, reads ORELA Data Files (ODF) created by SAMMY and uses graphics routines from the PLPLOT package. In addition, RSAP can read data and/or computed values from ASCII files with a format specified by the user. Plot output may be displayed in an X window, sent to a postscript file (rsap.ps), or sent to a color postscript file (rsap.psc). Thirteen plot types are supported, allowing the user to display cross section data, transmission data, errors, theory, Bayes fits, and residuals in various combinations. In this document the designations theory and Bayes refer to the initial and final theoretical cross sections, respectively, as evaluated by SAMMY. Special plot types include Bayes/Data, Theory--Data, and Bayes--Data. Output from two SAMMY runs may be compared by plotting the ratios Theory2/Theory1 and Bayes2/Bayes1 or by plotting the differences (Theory2-Theory1) and (Bayes2-Bayes1).

  19. Neutron cross sections for defect production by high-energy displacement cascades in copper

    International Nuclear Information System (INIS)

    Defect production cross sections for copper have been devised, based on computer simulations of displacement cascades. One thousand cascades ranging in energy from 200 eV to 200 keV were generated with the MARLOWE computer code. The cascades were subjected to a semi-empirical cascade quenching procedure and to short-term annealing with the ALSOME computer code. Functions were fitted to the numbers of defects produced as a function of primary knock-on atom (PKA) damage energy for the following defect types: 1) the total number of point defects after quenching and after short-term annealing, 2) the numbers of free interstitials and free vacancies after shortterm annealing, and 3) the numbers and sizes of vacancy and interstitial clusters after shortterm annealing. In addition, a function describing the number of distinct damage regions (lobes) per cascade was fitted to results of a graphical analysis of the cascade configurations. The defect production functions have been folded into PKA spectra using the NJOY nuclear data processing code system with ENDF/B-V nuclear data to yield neutron cross sections for defect production in copper. The free vacancy cross section displays much less variation with neutron energy than the cross sections for damage energy or total point defects

  20. Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

    Science.gov (United States)

    Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, S; Andrzejewski, J; Badurek, G; Baumann, P; Becvár, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Cortina, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Duran, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Furman, W; Goncalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, A; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stephan, C; Tagliente, G; Tain, J; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wisshak, K

    2004-10-15

    The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions. PMID:15524972

  1. Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

    Science.gov (United States)

    Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, S; Andrzejewski, J; Badurek, G; Baumann, P; Becvár, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Cortina, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Duran, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Furman, W; Goncalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, A; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stephan, C; Tagliente, G; Tain, J; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wisshak, K

    2004-10-15

    The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.

  2. γ-ray production cross sections of inelastic neutron scattering on natural molybdenum

    Directory of Open Access Journals (Sweden)

    Nyman M.

    2015-01-01

    Full Text Available γ-ray production cross sections of inelastic neutron scattering have been measured for molybdenum using the (n,n’γ-technique. The experiment was performed at the GELINA facility at the Institute for Reference Materials and Measurements (IRMM with the Gamma Array for Inelastic Neutron Scattering (GAINS setup. GAINS consisted of eight high purity germanium detectors at the time of this experiment. The sample was made of natural molybdenum, which includes seven isotopes (A = 92, 94, 95, 96, 97, 98, 100. The presence of so many isotopes in the sample leads to overlapping peaks in the spectra, which limits the amount of data that can be extracted from the analysis. Nevertheless, a total of 31 γ rays from the seven isotopes were analysed and γ-ray production cross sections were determined. Comparisons to other experimental results were made when such data was available. Also comparisons with model calculations were made with the Talys 1.6 code.

  3. Recent measurements of neutron capture cross sections in the fission product mass region

    International Nuclear Information System (INIS)

    The radiative capture cross sections for the separated isotopes of Sr, Y, Zr, Mo, Pd, Cd, Ba, La, Ce, Pr and Nd in the energy range 3 to 200 keV were measured with high energy resolution at the 40 m station of the Oak Ridge Electron Linear Accelerator. Maxwellian averaged 30 keV cross sections and average resonance parameters derived from the analysis are tabulated. A strong dependence of the average radiative widths on neutron binding energy is noted. This leads to a pronounced even-odd disparity. Neutron strength functions reduce with decreasing binding energy along an isotopic chain owing to the decreasing density of doorway states at the binding energy. 16 references

  4. Fast-neutron total and scattering cross sections of elemental palladium

    International Nuclear Information System (INIS)

    Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 1600. The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an optical potential that provides a good description of the measured values

  5. Determination of neutron-induced fission cross-sections of unstable nuclei via surrogate reaction method

    Indian Academy of Sciences (India)

    B K Nayak

    2014-11-01

    Heavy ion reaction studies around Coulomb barrier energies have been generally used to investigate the effect of the structure of projectile/target on reaction dynamics. Other than providing an understanding of basic physics of the reaction dynamics, some of these reactions have been used as tools to serve as surrogates of neutron-induced compound nuclear fission cross-sections involving unstable targets. In this paper, we report some of the recent results on the determination of neutron-induced fission cross-sections of unstable actinides present in Th–U and U–Pu fuel cycles by surrogate reaction method by employing transfer-induced fission studies with 6,7Li beams.

  6. Neutron-induced cross sections of actinides via the surrogate-reaction method

    Directory of Open Access Journals (Sweden)

    Ducasse Q.

    2013-12-01

    Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method has to be investigated. In particular, the absence of a compound nucleus formation and the Jπ dependence of the decay probabilities may question the method. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutron-induced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. The first results are hereby presented.

  7. Measurements of Neutron Captured Cross Sections in 1 Mev ∼ 2 MeV

    International Nuclear Information System (INIS)

    To obtain nuclear reaction data with fast neutron, the optimum condition of KIGAM bunching system, characteristics of KIGAM prompt gamma-ray detecting system and that of two dimensional data taking system such as gamma-ray time of flight and pulse height were investigated by Institute of Korea Geoscience and Mineral Resource (KIGAM). The pulse beam with the repetition rate of 125 ns and the width of 2 ns less than was obtained by the optimum bunching conditions. Also response and weighting function of prompt gamma-ray detector were obtained by the compton suppressed detector. Gamma time of flight spectrum and pulse height spectrum were measured by the two parameter data taking system. Neutron total cross sections and capture cross sections on 197Au have been measured and are being analyzed

  8. Neutron capture cross section of unstable 63Ni implications for stellar nucleosynthesis

    CERN Document Server

    Lederer, C; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Becares, V; Becvar, F; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calvino, F; Cano-Ott, D; Carrapico, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortes, G; Cortes-Giraldo, M.A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; Garcia, A R; Giubrone, G; Gomez-Hornillos, M B; Goncalves, I F; Gonzalez-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Korschinek, G; Krticka, M; Kroll, J; Langer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Martinez, T; Mastinu, P F; Mastromarco, M; Meaze, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondelaers, W; Paradela, C; Pavlik, A; Perkowski, J; Pignatari, M; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrio, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T J; Zugec, P

    2013-01-01

    The $^{63}$Ni($n, \\gamma$) cross section has been measured for the first time at the neutron time-of-flight facility n\\_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian Averaged Cross Sections were calculated for thermal energies from kT = 5 keV to 100 keV with uncertainties around 20%. Stellar model calculations for a 25 M$_\\odot$ star show that the new data have a significant effect on the $s$-process production of $^{63}$Cu, $^{64}$Ni, and $^{64}$Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

  9. Displacement cross sections and PKA spectra: tables and applications. [Neutron damage energy cross sections to 20 MeV, primary knockon atom spectra to 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Doran, D G; Graves, N J

    1976-12-01

    Damage energy cross sections to 20 MeV are given for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, niobium, molybdenum, tantalum, tungsten, lead, and 18Cr10Ni stainless steel. They are based on ENDF/B-IV nuclear data and the Lindhard energy partition model. Primary knockon atom (PKA) spectra are given for aluminum, iron, niobium, tantalum, and lead for neutron energies up to 15 MeV at approximately one-quarter lethargy intervals. The contributions of various reactions to both the displacement cross sections (taken to be proportional to the damage energy cross sections) and the PKA spectra are presented graphically. Spectral-averaged values of the displacement cross sections are given for several spectra, including approximate maps for the Experimental Breeder Reactor-II (EBR-II) and several positions in the Fast Test Reactor (FTR). Flux values are included to permit estimation of displacement rates. Graphs show integral PKA spectra for the five metals listed above for neutron spectra corresponding to locations in the EBR-II, the High Flux Isotope Reactor (HFIR), and a conceptual fusion reactor (UWMAK-I). Detailed calculations are given only for cases not previously documented. Uncertainty estimates are included.

  10. CHC program for calculation of the adjoint neutron cross sections on the basis of evaluated neutron data of the ENDF/B

    International Nuclear Information System (INIS)

    The features and the algorithm of the program to calculate adjoint neutron cross sections on the basis of the continuous energy neutron cross sections as well as energy and angular distributions are described. The calculated adjoint cross sections are intended for Monte Carlo investigation of the nonuniform adjoint Boltzmann equation. 16 refs

  11. Neutron cross-sections for advanced nuclear systems: the n_TOF project at CERN

    Science.gov (United States)

    Barbagallo, M.; Mastromarco, M.; Colonna, N.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Hernández-Prieto, A.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Krtička, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Leong, L. S.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P. F.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondalaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Rubbia, C.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; Žugec, P.

    2014-12-01

    The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n_TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.

  12. Neutron cross-sections for advanced nuclear systems: the n_TOF project at CERN

    Directory of Open Access Journals (Sweden)

    Barbagallo M.

    2014-01-01

    Full Text Available The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n_TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.

  13. Assessment of the neutron cross section database for mercury for the ORNL spallation source

    Energy Technology Data Exchange (ETDEWEB)

    Leal, L.C.; Spencer, R.R.; Ingersoll, D.T.; Gabriel, T.A. [Oak Ridge National Lab., TN (United States)

    1996-06-01

    Neutron source generation based on a high energy particle accelerator has been considered as an alternative to the canceled Advanced Neutron Source project at Oak Ridge National Laboratory. The proposed technique consists of a spallation neutron source in which neutrons are produced via the interaction of high-energy charged particles in a heavy metal target. Preliminary studies indicate that liquid mercury bombarded with GeV protons provides an excellent neutron source. Accordingly, a survey has been made of the available neutron cross-section data. Since it is expected that spectral modifiers, specifically moderators, will also be incorporated into the source design, the survey included thermal energy, resonance region, and high energy data. It was found that data of individual isotopes were almost non-existent and that the only evaluation found for the natural element had regions of missing data or discrepant data. Therefore, it appears that to achieve the desired degree of accuracy in the spallation source design it is necessary to re-evaluate the mercury database including making new measurements. During the presentation the currently available data will be presented and experiments proposed which can lead to design quality cross sections.

  14. Slow neutron total cross-section of Al6061 at low temperatures

    CERN Document Server

    Granada, J R

    2000-01-01

    This work presents evaluations of the total cross-section and its components, corresponding to the aluminum based alloy Al6061 at a few temperatures of interest, over the neutron energy range from 10 sup - sup 5 to 10 eV. A practical procedure for subtraction of the cold source's vessel contribution to the measured emerging spectra is discussed, and data given for the specific cases where Al6061 is used as the vessel material.

  15. A unified Monte Carlo approach to fast neutron cross section data evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.; Nuclear Engineering Division

    2008-03-03

    A unified Monte Carlo (UMC) approach to fast neutron cross section data evaluation that incorporates both model-calculated and experimental information is described. The method is based on applications of Bayes Theorem and the Principle of Maximum Entropy as well as on fundamental definitions from probability theory. This report describes the formalism, discusses various practical considerations, and examines a few numerical examples in some detail.

  16. Above-threshold structure in {sup 244}Cm neutron-induced fission cross section

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    The quasi-resonance structure appearing above the fission threshold in neutron-induced fission cross section of {sup 244}Cm(n,f) is interpreted. It is shown to be due to excitation of few-quasiparticle states in fissioning {sup 245}Cm and residual {sup 244}Cm nuclides. The estimate of quasiparticle excitation thresholds in fissioning nuclide {sup 245}Cm is consistent with pairing gap and fission barrier parameters. (author)

  17. Fast neutron spectrum unfolding of a TRIGA Mark II reactor and measurement of spectrum-averaged cross sections. Integral tests of differential cross sections of neutron threshold reactions

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.S.; Hossain, S.M.; Khan, R. [Atomic Energy Research Establishment, Dhaka (Bangladesh). Inst. of Nuclear Science and Technology (INST); Sudar, S. [Debrecen Univ. (Hungary). Inst. of Experimental Physics; Zulquarnain, M.A. [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh); Qaim, S.M. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Medizin (INM-5)

    2013-07-01

    The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the 3MW TRIGA Mark II reactor at Savar, Dhaka, Bangladesh, was unfolded by activating several metal foils to induce threshold nuclear reactions covering the whole spectrum, and then doing necessary iterative calculations utilizing the activation results and the code SULSA. The analysed shape of the spectrum in the TRIGA core was found to be similar to that of the pure {sup 235}U-fission spectrum, except for the energies between 0.5 and 1.5 MeV, where it was slightly higher than the fission spectrum. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured in this work were compared with the recommended values for a pure fission spectrum as well as with the integrated data deduced from measured and evaluated excitation functions of a few reactions given in some data files. The good agreement between integral measurements and integrated data in case of well-investigated reactions shows that the fast neutron field at the TRIGA Mark II reactor can be used for validation of evaluated data of neutron threshold reactions. (orig.)

  18. Fast neutron spectrum unfolding of a TRIGA Mark II reactor and measurement of spectrum-averaged cross sections. Integral tests of differential cross sections of neutron threshold reactions

    International Nuclear Information System (INIS)

    The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the 3MW TRIGA Mark II reactor at Savar, Dhaka, Bangladesh, was unfolded by activating several metal foils to induce threshold nuclear reactions covering the whole spectrum, and then doing necessary iterative calculations utilizing the activation results and the code SULSA. The analysed shape of the spectrum in the TRIGA core was found to be similar to that of the pure 235U-fission spectrum, except for the energies between 0.5 and 1.5 MeV, where it was slightly higher than the fission spectrum. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured in this work were compared with the recommended values for a pure fission spectrum as well as with the integrated data deduced from measured and evaluated excitation functions of a few reactions given in some data files. The good agreement between integral measurements and integrated data in case of well-investigated reactions shows that the fast neutron field at the TRIGA Mark II reactor can be used for validation of evaluated data of neutron threshold reactions. (orig.)

  19. Curium-245 and curium-247 neutron cross sections between 10 keV and 10 MeV

    International Nuclear Information System (INIS)

    The optical model code 2PLUS and the statistical model codes COMNUC and CASCADE were used to compute neutron cross sections for Cm-245 and Cm-247 between 10 keV and 10 MeV. Cross sections for elastic and inelastic scattering, radiative capture, fission, and the (n,2n) reactions were computed. The parameters for the fission model were selected to yield agreement with the cross sections from the Physics-8 bomb shot. Pu-239 cross sections were calculated and compared with existing cross section evaluations to demonstrate the validity of the calculational methods

  20. Measuring neutron-induced fission cross-section of shortlived actinides using a lead neutron-slowing-down spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Granier, T. E-mail: thierry.granier@cea.fr; Pangault, L.; Ethvignot, T.; Haight, R.C.; Ledoux, X.; Meot, V.; Patin, Y.; Pras, P.; Szmigiel, M.; Rundberg, R.S.; Wilhelmy, J.B

    2003-06-21

    The 'lead-slowing-down-spectrometer' method is an established technique for measuring neutron-induced reaction cross-sections. It is known to provide high neutron fluences below 100 keV. In this work, the possibility of applying this method to the measurement of the neutron-induced fission cross-section of shortlived actinides and in particular of the 77 eV isomer of {sup 235}U is investigated. Numerical simulations and a test-experiment using a photovaltaic cell fission detector demonstrate the feasibility of such a measurement at the Los Alamos Neutron Science Center using 800 MeV proton-induced spallation to provide source neutrons.

  1. Measurements of fast—neutron capture cross sections for 159Tb and 169Tm

    Institute of Scientific and Technical Information of China (English)

    ChenJin-Xiang; ShiZhao-Min; 等

    1998-01-01

    The neutron capture cross sections for 159Tb and 169Tm relative to the 197Au (n,γ)198Au reaction are measured at neutron energies of 0.57,1.10 and 1.60 MeV by using the activation method.The activities of the products are measured with a high resolution HPGe detector gamma-ray spectrometer.The errors of the present work are 5-6% for Tb,6-7% for Tm.The recommended data in energy region of 0.4-3.0MeV are given as compared with other data published previously.

  2. Prompt gamma-ray detectors for the measurement of neutron capture cross-sections

    International Nuclear Information System (INIS)

    A review is given of current techniques for detecting prompt gamma-radiation as a means of measuring total capture cross-sections. The discussion is generally restricted to systems with low or moderate gamma-ray energy resolution. Three classes of detector are considered: (1) the total absorption type; (2) detectors with efficiency proportional to gamma-ray energy; and (3) detectors of low efficiency and known gamma-ray response. Particular attention is given to the problems of background from reactions which compete with neutron capture, and the sensitivity of capture detectors to scattered neutrons. The extraction of capture yields from observed data is briefly considered

  3. Measurements of neutron cross sections for advanced nuclear energy systems at n_TOF (CERN

    Directory of Open Access Journals (Sweden)

    Barbagallo M.

    2014-03-01

    Full Text Available The n_TOF facility operates at CERN with the aim of addressing the request of high accuracy nuclear data for advanced nuclear energy systems as well as for nuclear astrophysics. Thanks to the features of the neutron beam, important results have been obtained on neutron induced fission and capture cross sections of U, Pu and minor actinides. Recently the construction of another beam line has started; the new line will be complementary to the first one, allowing to further extend the experimental program foreseen for next measurement campaigns.

  4. Neutron cross-section libraries in the AMPX master interface format for thermal and fast reactors

    International Nuclear Information System (INIS)

    Neutron cross-section libraries in the AMPX master interface format have been created for three reactor types. Included are an 84-group library for use with light-water reactors, a 27-group library for use with heavy-water CANDU reactors and a 126-group library for use with liquid metal fast breeder reactors. In general, ENDF/B data were used in the creation of these libraries, and the nuclides included in each library should be sufficient for most neutronic analyses of reactors of that type. Each library has been used successfully in fuel depletion calculations

  5. Cross section measurement for (n,n{alpha}) reactions by 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kasugai, Y.; Ikeda, Y.; Uno, Y. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yamamoto, H.; Kawade, K.

    1997-03-01

    Nine (n,n{alpha}) cross sections for (n,n{alpha}) reactions induced by 13.5-14.9 MeV neutrons were measured for {sup 51}V, {sup 65}Cu, {sup 71}Ga, {sup 76}Ge, {sup 87}Rb, {sup 91}Zr, {sup 93}Nb, {sup 96}Zr and {sup 109}Ag isotopes by using Fusion Neutronics Source (FNS) at JAERI. The reactions for 91Zr and 96Zr were measured for the first time. The evaluated data of JENDL-3 and ENDF/B-VI were compared with the present data. Some of the evaluated values are much different from our data by a factor more than ten. (author)

  6. Validation of multigroup neutron cross sections and calculational methods for the advanced neutron source against the FOEHN critical experiments measurements

    Energy Technology Data Exchange (ETDEWEB)

    Smith, L.A.; Gallmeier, F.X. [Oak Ridge Institute for Science and Energy, TN (United States); Gehin, J.C. [Oak Ridge National Lab., TN (United States)] [and others

    1995-05-01

    The FOEHN critical experiment was analyzed to validate the use of multigroup cross sections and Oak Ridge National Laboratory neutronics computer codes in the design of the Advanced Neutron Source. The ANSL-V 99-group master cross section library was used for all the calculations. Three different critical configurations were evaluated using the multigroup KENO Monte Carlo transport code, the multigroup DORT discrete ordinates transport code, and the multigroup diffusion theory code VENTURE. The simple configuration consists of only the fuel and control elements with the heavy water reflector. The intermediate configuration includes boron endplates at the upper and lower edges of the fuel element. The complex configuration includes both the boron endplates and components in the reflector. Cross sections were processed using modules from the AMPX system. Both 99-group and 20-group cross sections were created and used in two-dimensional models of the FOEHN experiment. KENO calculations were performed using both 99-group and 20-group cross sections. The DORT and VENTURE calculations were performed using 20-group cross sections. Because the simple and intermediate configurations are azimuthally symmetric, these configurations can be explicitly modeled in R-Z geometry. Since the reflector components cannot be modeled explicitly using the current versions of these codes, three reflector component homogenization schemes were developed and evaluated for the complex configuration. Power density distributions were calculated with KENO using 99-group cross sections and with DORT and VENTURE using 20-group cross sections. The average differences between the measured values and the values calculated with the different computer codes range from 2.45 to 5.74%. The maximum differences between the measured and calculated thermal flux values for the simple and intermediate configurations are {approx} 13%, while the average differences are < 8%.

  7. Neutron Capture Cross Section Measurement on 91Zr at J-PARC/MLF/ANNRI

    Directory of Open Access Journals (Sweden)

    Hori Jun-ichi

    2015-01-01

    Full Text Available The neutron capture cross section measurement on 91Zr was performed at neutron TOF beam line ANNRI installed at J-PARC/MLF. Prompt capture gamma rays from the sample were detected with an array of large Ge detectors at a distance of 21.5 m from the spallation neutron source by the time-of-fligh (TOF method. The neutron capture gamma-ray pulse-height spectra from the 182-eV p-wave resonance and the 292-eV s-wave resonance were obtained by gating on the TOF regions, respectively. Though the decay patterns of primary transitions from the capture state were quite different between resonances, the prominent characteristics common to both resonances was the very strong ground-state transition from the 935-keV state. Therefore, a ground-state transition method was applied to obtain the capture yield, so that the background components due to impurities were successfully eliminated. The preliminary result of the neutron capture cross section for 91Zr up to 5 keV is presented.

  8. Theoretical neutron-capture cross sections for r-process nucleosynthesis in the $^{48}$Ca region

    CERN Document Server

    Rauscher, T; Kratz, K -L; Balogh, W; Oberhummer, H

    2015-01-01

    We calculate neutron capture cross sections for r-process nucleosynthesis in the $^{48}$Ca region, namely for the isotopes $^{40-44}$S, $^{46-50}$Ar, $^{56-66}$Ti, $^{62-68}$Cr, and $^{72-76}$Fe. While previously only cross sections resulting from the compound nucleus reaction mechanism (Hauser-Feshbach) have been considered, we recalculate not only that contribution to the cross section but also include direct capture on even-even nuclei. The level schemes, which are of utmost importance in the direct capture calculations, are taken from quasi-particle states obtained with a folded-Yukawa potential and Lipkin-Nogami pairing. Most recent deformation values derived from experimental data on $\\beta$-decay half lives are used where available. Due to the consideration of direct capture, the capture rates are enhanced and the "turning points" in the r-process path are shifted to slightly higher mass numbers. We also discuss the sensitivity of the direct capture cross sections on the assumed deformation.

  9. ZZ MONTAGE-400, Neutron Activation 100-Group Cross-Section Library of Fusion Reactor Materials

    International Nuclear Information System (INIS)

    1 - Description of problem or function: Format: GAM-II group structure and ANISN; Number of groups: 100-group cross sections. Nuclides: H, He, Li, Be, B, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Ag, Sn, Cs, Hf, Ta, W, Re, Au, Pb. Origin: derived from ENDF/B, or calculated at Brookhaven National Laboratory. Weighting spectrum: 1/E except near 14 MeV where a thermally broadened fusion peak, assuming a temperature of 20 MeV, is employed. This data library contains 100- group cross sections, with GAM-II group structure, for 421 neutron activation reactions with fusion reactor structural and coolant materials. The weighting function is 1/E except near 14 MeV where a thermally broadened fusion peak, assuming a temperature of 20 MeV, is employed. The library also contains half life information for the activated nuclei. 2 - Method of solution: The thermal group cross sections were calculated from the 2200 m/s value, when available, otherwise from the group 99 value. The majority of the non-thermal cross sections were derived from pointwise data derived from ENDF/B, or calculated at Brookhaven National Laboratory using the nuclear systematics code THRESH. These were converted to multigroup from using the codes ETOG and NJOY

  10. TRANSX-2.15, Neutron Gamma Particle Transport Tables from MATXS Format Cross-Sections

    International Nuclear Information System (INIS)

    1 - Description of program or function: TRANSX is a computer code that reads nuclear data from a library in MATXS format and produces transport tables compatible with many discrete-ordinates (SN) and diffusion codes. Tables can be produced for neutron, photon, charged-particle, or coupled transport. Options include adjoint tables, mixtures, homogeneous or heterogeneous self-shielding, group collapse, homogenization, thermal up-scatter, prompt or steady-state fission, transport corrections, elastic removal corrections, and flexible response function edits. 2 - Method of solution: TRANSX reads through the materials in a MATXS library and accumulates the cross sections into a transport table using the user's mix instructions. At the same time, response function edit cross sections are accumulated using the user's edit instructions. They can thus be any linear combination of the cross sections available in the library. When the table is complete, it is written out in the desired format. Output options include DTF-style card images, FIDO, ISOTXS, and the binary group-ordered GOXS format. Self-shielding is handled using the background cross section method. Heterogeneity options include homogeneous mixtures, escape using mean chord, lattices of cylinders by the Bell or Sauer approximations, and reflected or periodic slab cell by the bell or E3 approximations. 3 - Restrictions on the complexity of the problem: Only narrow- resonance self-shielding is available in this version. This may affect accuracy for thermal problems

  11. Neutron capture cross section measurements for 238U in the resonance region at GELINA

    Science.gov (United States)

    Kim, H. I.; Paradela, C.; Sirakov, I.; Becker, B.; Capote, R.; Gunsing, F.; Kim, G. N.; Kopecky, S.; Lampoudis, C.; Lee, Y.-O.; Massarczyk, R.; Moens, A.; Moxon, M.; Pronyaev, V. G.; Schillebeeckx, P.; Wynants, R.

    2016-06-01

    Measurements were performed at the time-of-flight facility GELINA to determine the 238U(n, γ) cross section in the resonance region. Experiments were carried out at a 12.5 and 60m measurement station. The total energy detection principle in combination with the pulse height weighting technique was applied using C6D6 liquid scintillators as prompt γ-ray detectors. The energy dependence of the neutron flux was measured with ionisation chambers based on the 10B(n, α) reaction. The data were normalised to the isolated and saturated 238U resonance at 6.67 eV. Special procedures were applied to reduce bias effects due to the weighting function, normalization, dead time and background corrections, and corrections related to the sample properties. The total uncertainty due to the weighting function, normalization, neutron flux and sample characteristics is about 1.5%. Resonance parameters were derived from a simultaneous resonance shape analysis of the GELINA capture data and transmission data obtained previously at a 42m and 150m station of ORELA. The parameters of resonances below 500 eV are in good agreement with those resulting from an evaluation that was adopted in the main data libraries. Between 500 eV and 1200 eV a systematic difference in the neutron width is observed. Average capture cross section data were derived from the experimental capture yield in the energy region between 3.5 keV and 90 keV. The results are in good agreement with an evaluated cross section resulting from a least squares fit to experimental data available in the literature prior to this work. The average cross section data derived in this work were parameterised in terms of average resonance parameters and included in a least squares analysis together with other experimental data reported in the literature.

  12. Theoretical and experimental cross sections for neutron reactions on 64Zinc

    International Nuclear Information System (INIS)

    Accurate measurements of the 64Zn (n,2n) 64Cu and 64Zn (n,p) 63Zn cross sections at 14.8 MeV have been made using a Texas Nuclear Neutron Generator and the activation technique. A NaI(T1) spectrometer (using two 6'' x 6'' NaI detectors/crystals) was used to measure the gamma radiation emitted in coincidence from the positron-emitting decay products. The measurements were made relative to 65Cu (n,2n) /64/Cu and 63Cu (n,2n) 62Cu cross sections, which have similar half-lives, radiation emission, and were previously measured to high accuracy (2 percent). The value obtained for the (n,2n) measurement was 199 /+-/ 6 millibarns, and a value of 176 /+-/ 4.5 millibarns was obtained for the (n,p) measurement. In concert, a theoretical analysis of neutron induced reactions on /64/Zn was performed at Los Alamos National Laboratory using the Hauser-Feshbach statistical theory in the GNASH code over an energy range of 100 keV to 20 MeV. Calculations included width fluctuation corrections, direct reaction contributions, and preequilibrium corrections above 6 MeV. Neutron optical model potentials were determined for zinc. The theoretical values agree with the new 14.8 MeV measurements approximately within experimental error, with calculations of 201 millibarns for the (n,2n) cross section and 170 millibarns for the (n,p) cross section. Results from the analysis will be made available in National Evaluated Nuclear Data Format (ENDF/B) for fusion energy applications. 50 refs., 34 figs., 10 tabs

  13. Theoretical and experimental cross sections for neutron reactions on /sup 64/Zinc

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, D.A.

    1988-03-01

    Accurate measurements of the /sup 64/Zn (n,2n)/sup 63/Zn and /sup 64/Zn (n,p)/sup 64/Cu cross sections at 14.8 MeV have been made using a Texas Nuclear Neutron Generator and the activation technique. A NaI(Tl) spectrometer (using two 6'' x 6'' NaI detectors/crystals) was ued to measure the gamma radiation emitted in coincidence from the positron-emitting decay products. The measurements were made relative to /sup 65/Cu (n,2n)/sup 64/Cu and /sup 63/Cu (n,2n)/sup 62/Cu cross sections, which have similar half-lives, radiation emission, and were previously measured to high accuracy (2%). The value obtained for the (n,2n) measurement was 199 +- 6 millibarns, and a value of 176 +- 4.5 millibarns was obtained for the (n,p) measurement. In concert, a theoretical analysis of neutron induced reactions on /sup 64/Zn was performed at Los Alamos National Laboratory using the Hauser-Feshbach statistical theory in the GNASH code over an energy range of 100 keV to 20 MeV. Calculations included width fluctuation corrections, direct reaction contributions, and preequilibrium corrections above 6 MeV. Neutron optical model potentials were determined for zinc. The theoretical values agree with the new 14.8 MeV measurements approximately within experimental error, with calculations of 201 millibarns for the (n,2n) cross section and 170 millibarns for the (n,p) cross section. Results from the analysis will be made available in National Evaluated Nuclear Data Format (ENDF/B) for fusion energy applications. 50 refs., 34 figs., 10 tabs.

  14. Principle and Uncertainty Quantification of an Experiment Designed to Infer Actinide Neutron Capture Cross-Sections

    Energy Technology Data Exchange (ETDEWEB)

    G. Youinou; G. Palmiotti; M. Salvatorre; G. Imel; R. Pardo; F. Kondev; M. Paul

    2010-01-01

    An integral reactor physics experiment devoted to infer higher actinide (Am, Cm, Bk, Cf) neutron cross sections will take place in the US. This report presents the principle of the planned experiment as well as a first exercise aiming at quantifying the uncertainties related to the inferred quantities. It has been funded in part by the DOE Office of Science in the framework of the Recovery Act and has been given the name MANTRA for Measurement of Actinides Neutron TRAnsmutation. The principle is to irradiate different pure actinide samples in a test reactor like INL’s Advanced Test Reactor, and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after neutron irradiation allows the energy integrated neutron cross-sections to be inferred since the relation between the two are the well-known neutron-induced transmutation equations. This approach has been used in the past and the principal novelty of this experiment is that the atom densities of the different transmutation products will be determined with the Accelerator Mass Spectroscopy (AMS) facility located at ANL. While AMS facilities traditionally have been limited to the assay of low-to-medium atomic mass materials, i.e., A < 100, there has been recent progress in extending AMS to heavier isotopes – even to A > 200. The detection limit of AMS being orders of magnitude lower than that of standard mass spectroscopy techniques, more transmutation products could be measured and, potentially, more cross-sections could be inferred from the irradiation of a single sample. Furthermore, measurements will be carried out at the INL using more standard methods in order to have another set of totally uncorrelated information.

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

    Science.gov (United States)

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

    2006-03-01

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

  16. Double differential neutron emission cross sections, numerical tables and figures (1983)

    International Nuclear Information System (INIS)

    Numerical data tables for experimental double differential neutron emission cross sections with a 14 MeV neutron source are given. The experimental method is explained in Ref. 1. The data on Li, Be, C, O, Al, Cr, Fe, Ni, Mo, Cu, Nb and Pb correspond to the presentation by the authors at the 1982 Antwerp Conference (Ref. 1). Additional data for D (Ref. 2), F and Si (Ref. 3) are given. The figures showing the experimental data in comparison with the calculated double differential cross sections using ENDF/B-4 data are attached. In the comparison on carbon, the ENDF/B-5 data were used. In the figures, the corrected experimental data with a multiple scattering code are given together with the raw data. The multiple scattering correction (Ref. 4) was performed by using the calculated double differential cross sections from the ENDF/B-4 data. In the data tables, the experimental data without the multiple scattering correction are given. The numerical data tables were made by using the EXFOR format of the NEA Data Bank. (Kako, I.)

  17. Neutron transmission and capture cross section measurements for 241Am at the GELINA facility

    International Nuclear Information System (INIS)

    Resonance parameters for neutron-induced reactions on 241Am below 110 eV have been determined. The parameters result from a resonance shape analysis of transmission and capture data measured at the time-of-flight facility GELINA, with the accelerator operating at a 50 Hz repetition rate. The transmission experiments were carried out at a 25 m station using a Li glass scintillator. The capture experiments were performed at a 12.5 m station by applying the total energy detection principle in combination with the pulse height weighting technique using a pair of C6D6 detectors. The normalization of the capture data was determined by a combined least squares adjustment of the transmission and capture data. From the adjusted resonance parameters a capture cross section of 749 ± 35 b for a neutron energy of 0.0253 eV and an average radiation width of Γγ = 42.0 meV for s-wave resonances were obtained. A missing-level analysis for s-wave neutron resonances within the statistical model results in compatible values with previous estimates. The neutron widths obtained in this work are approximately 22% larger compared to other experimental data and evaluated data libraries. Also the thermal capture cross section is larger than most of the recommended values. However, the resonance parameter file presented in this work is consistent with results of both integral experiments and of the experimentally determined resonance integrals. (authors)

  18. Measurement of the inelastic neutron scattering cross section of 56Fe

    Directory of Open Access Journals (Sweden)

    Nolte R.

    2010-10-01

    Full Text Available At the superconducting electron linear accelerator ELBE at Forschungszentrum Dresden-Rossendorf the neutron time-of-flight facility nELBE has become operational. Fast neutrons in the energy range from 200 keV to 10 MeV are produced by the pulsed electron beam from ELBE impinging on a liquid lead circuit as a radiator. The short beam pulses of 10 ps provide the basis for an excellent time resolution for neutron time-of-flight experiments, giving an energy resolution of about <1% at 1 MeV with a short flight path of 5 m. By means of a “double-time-of-flight” setup the (n,nâγ cross section to the first excited state of 56Fe has been measured over the whole energy range without knowledge about cross sections of higher-lying levels. Plastic scintillators were used to detect the inelastically scattered neutron and BaF2 detectors to detect the correlated γ-ray.

  19. The thermal neutron capture cross section of the radioactive isotope $^{60}$Fe

    CERN Document Server

    Heftrich, T; Dressler, R; Eberhardt, K; Endres, A; Glorius, J; Göbel, K; Hampel, G; Heftrich, M; Käppeler, F; Lederer, C; Mikorski, M; Plag, R; Reifarth, R; Stieghorst, C; Schmidt, S; Schumann, D; Slavkovská, Z; Sonnabend, K; Wallner, A; Weigand, M; Wiehl, N; Zauner, S

    2015-01-01

    50% of the heavy element abundances are produced via slow neutron capture reactions in different stellar scenarios. The underlying nucleosynthesis models need the input of neutron capture cross sections. One of the fundamental signatures for active nucleosynthesis in our galaxy is the observation of long-lived radioactive isotopes, such as $^{60}$Fe with a half-life of $2.60\\times10^6$ yr. To reproduce this $\\gamma$-activity in the universe, the nucleosynthesis of $^{60}$Fe has to be understood reliably. A $^{60}$Fe sample produced at the Paul-Scherrer-Institut was activated with thermal and epithermal neutrons at the research reactor at the Johannes Gutenberg-Universit\\"at Mainz. The thermal neutron capture cross section has been measured for the first time to $\\sigma_{\\text{th}}=0.226 \\ (^{+0.044}_{-0.049})$ b. An upper limit of $\\sigma_{\\text{RI}} < 0.50$ b could be determined for the resonance integral. An extrapolation towards the astrophysicaly interesting energy regime between $kT$=10 keV and 100 ke...

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

    Science.gov (United States)

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

    2014-03-01

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

  1. Measurement of the thermal neutron capture cross section and the resonance integral of radioactive Hf182

    Science.gov (United States)

    Vockenhuber, C.; Bichler, M.; Wallner, A.; Kutschera, W.; Dillmann, I.; Käppeler, F.

    2008-04-01

    The neutron capture cross sections of the radioactive isotope Hf182 (t1/2=8.9×106 yr) in the thermal and epithermal energy regions have been measured by activation at the TRIGA Mark-II reactor of the Atomic Institute of the Austrian Universities in Vienna, Austria, and subsequent γ-ray spectroscopy of Hf183. High values for the thermal (kT=25 meV) cross section σ0=133±10 b and for the resonance integral I0=5850±660 b were found. Additionally, the absolute intensities of the main γ-ray transitions in the decay of Hf182 have been considerably improved.

  2. Determination of cross sections for the production of low-energy monoenergetic neutron fields

    International Nuclear Information System (INIS)

    The response of a neutron detector, defined as the reading of the device per unit of incident fluence or dose, varies with neutron energy. The experimental determination of this variation, i.e. of the response function of this instrument, has to be performed by facilities producing monoenergetic neutron fields. These neutrons are commonly produced by interaction between accelerated ions (proton or deuteron) onto a thin target composed of a reactive layer deposited on a metallic backing. Using the 7Li(p, n), 3H(p, n), 2H(d, n) and 3H(d, n) reactions, monoenergetic neutrons are obtained between 120 keV and 20 MeV in the ion beam direction (0 deg.). To reach lower neutron energies, the angle of the measuring point with respect to the ion beam direction can be increased. However, this method presents several problems of neutron energy and fluence homogeneities over the detector surface, as well as an important increase of the scattered neutron contribution. Another solution is to investigate other nuclear reactions, as 45Sc(p, n) allowing to extend the neutron energy range down to 8 keV at 0 deg.. A complete study of this reaction and its cross section has been undertaken within the framework of a scientific cooperation between the laboratory of neutron metrology and dosimetry (IRSN, France), two European national metrological institutes, the National Physical Laboratory (UK) and the Physikalisch-Technische Bundesanstalt (Germany), and IRMM, the Institute for Reference Materials and Measurements (EC). In parallel, other possible reactions have been investigated: 65Cu(p, n), 51V(p, n), 57Fe(p, n), 49Ti(p, n), 53Cr(p, n) and 37Cl(p, n). They were compared in terms of neutron fluence and minimum energy of the produced neutrons. (author)

  3. Neutron capture cross sections of $^{70,72,73,74,76}$ Ge at n_TOF EAR-1

    CERN Multimedia

    We propose to measure the (n;$\\gamma$ ) cross sections of the isotopes $^{70;72;73;74;76}$Ge. Neutron induced reactions on Ge are of importance for the astrophysical slow neutron capture process, which is responsible for forming about half of the overall elemental abundances heavier than Fe. The neutron capture cross section on Ge affects the abundances produced in this process for a number of heavier isotopes up to a mass number of A = 90. Additionally, neutron capture on Ge is of interest for low background experiments involving Ge detectors. Experimental cross section data presently available for Ge (n;$\\gamma$ ) are scarce and cover only a fraction of the neutron energy range of interest. (n;$\\gamma$ ) cross sections will be measured in the full energy range from 25 meV to about 200 keV at n TOF EAR-1.

  4. Thermal neutron radiative cross sections for Li,76,9Be,B,1110,C,1312, and N,1514

    Science.gov (United States)

    Firestone, R. B.; Revay, Zs.

    2016-05-01

    Total thermal radiative neutron cross sections have been measured on natural and enriched isotopic targets containing Li,76,9Be,B,1110,C,1312, and N,1514 with neutron beams from the Budapest Reactor. Complete neutron capture γ -ray decay schemes were measured for each isotope. Absolute transition probabilities have been determined by a least-squares fit of the transition intensities, corrected for internal conversion, to the (n ,γ ) decay schemes. The γ -ray cross sections were standardized using stoichiometric compounds containing both the isotope of interest and another element whose γ -ray cross sections are well known. Total cross sections σ0 were then determined for each isotope from the γ -ray cross sections and transition probabilities. For the 11B(n ,γ )12B reaction decay transition probabilities were determined for the γ rays from 12B (t1 /2=20.20 ms) β- decay.

  5. Neutron cross-sections for next generation reactors: new data from n_TOF.

    Science.gov (United States)

    Colonna, N; Abbondanno, U; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviani, M; Calviño, F; Cano-Ott, D; Capote, R; de Albornoz, A Carrillo; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vicente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2010-01-01

    In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry.

  6. Neutron cross-sections for next generation reactors: New data from n_TOF

    CERN Document Server

    Colonna, N; Eleftheriadis, C; Leeb, H; Tain, J L; Calvino, F; Herrera-Martinez, A; Savvidis, I; Vlachoudis, V; Haas, B; Abbondanno, U; Vannini, G; Konovalov, V; Marques, L; Wiescher, M; de Albornoz, A Carrillo; Audouin, L; Mengoni, A; Quesada, J; Becvar, F; Plag, R; Cennini, P; Mosconi, M; Duran, I; Rauscher, T; Ketlerov, V; Couture, A; Capote, R; Sarchiapone, L; Pigni, M T; Vlastou, R; Domingo-Pardo, C; Pavlopoulos, P; Karamanis, D; Krticka, M; Jericha, E; Ferrari, A; Martinez, T; Oberhummer, H; Karadimos, D; Plompen, A; Isaev, S; Terlizzi, R; Kaeppeler, F; Cortes, G; Cox, J; Voss, F; Pretel, C; Berthoumieux, E; Dolfini, R; Vaz, P; Griesmayer, E; Heil, M; Lopes, I; Lampoudis, C; Walter, S; Calviani, M; Gonzalez-Romero, E; Stephan, C; Igashira, M; Papachristodoulou, C; Aerts, G; Tavora, L; Wendler, H; Milazzo, P M; Rudolf, G; Andrzejewski, J; Villamarin, D; Ferreira-Marques, R; O'Brien, S; Gunsing, F; Reifarth, R; Perrot, L; Lindote, A; Neves, F; Poch, A; Gramegna, F; Kerveno, M; Rubbia, C; Koehler, P; Dahlfors, M; Wisshak, K; Fujii, K; Salgado, J; Dridi, W; Ventura, A; Andriamonje, S; Dillman, I; Assimakopoulos, P; Ferrant, L; Lozano, M; Patronis, N; Chiaveri, E; Guerrero, C; Kadi, Y; Baumann, P; Moreau, C; Oshima, M; Rullhusen, P; Furman, W; David, S; Marrone, S; Paradela, C; Vicente, M C; Tassan-Got, L; Cano-Ott, D; Alvarez-Velarde, F; Massimi, C; Mastinu, P; Pancin, J; Papadopoulos, C; Tagliente, G; Alvarez, H; Haight, R; Goverdovski, A; Chepel, V; Rosetti, M; Kossionides, E; Badurek, G; Marganiec, J; Lukic, S; Frais-Koelbl, H; Pavlik, A; Goncalves, I

    2010-01-01

    In 2002, an innovative neutron time-of-flight facility started operation at CERN: n\\_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n\\_TOF is presented, together with plans for new measurements related to nuclear industry. (C) 2010 Elsevier Ltd. All rights reserved.

  7. The {sup 234}U neutron capture cross section measurement at the n TOF facility

    Energy Technology Data Exchange (ETDEWEB)

    Lampoudis, C.; Abbondanno, U.; Aerts, G.; A lvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, O.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kappeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    The neutron capture cross-section of {sup 234}U has been measured for energies from thermal up to the keV region in the neutron time-of-flight facility n-TOF, based on a spallation source located at CERN. A 4{pi} BaF{sub 2} array composed of 40 crystals, placed at a distance of 184.9 m from the neutron source, was employed as a total absorption calorimeter (TAC) for detection of the prompt {gamma}-ray cascade from capture events in the sample. This text describes the experimental setup, all necessary steps followed during the data analysis procedure. Results are presented in the form of R-matrix resonance parameters from fits with the SAMMY code and compared to the evaluated data of Endf in the relevant energy region, indicating the good performance of the n-TOF facility and the TAC. (authors)

  8. Neutron cross-sections for next generation reactors: new data from n_TOF.

    Science.gov (United States)

    Colonna, N; Abbondanno, U; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviani, M; Calviño, F; Cano-Ott, D; Capote, R; de Albornoz, A Carrillo; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vicente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2010-01-01

    In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry. PMID:20096595

  9. Actinide neutron induced cross section measurements using the oscillation technique in the Minerve reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, B.; Leconte, P.; Gruel, A.; Antony, M.; Di-Salvo, J.; Hudelot, J.P.; Pepino, A.; Lecluze, A. [CEA Cadarache, DEN/CAD/DER/SPRC/LEPh, 13 - Saint-Paul-lez-Durance (France)

    2009-07-01

    CEA is deeply involved research programs concerning nuclear fuel advanced studies (actinides, plutonium), waste management, the scientific and technical support of French PWR reactors and EPR reactor, and innovative systems. In this framework, specific neutron integral experiments have been carried out in the critical ZPR (zero power reactor) facilities of the CEA at Cadarache such as MINERVE, EOLE and MASURCA. This paper deals with MINERVE Pool Reactor experiments. MINERVE is mainly devoted to neutronics studies of different reactor core types. The aim is to improve the knowledge of the integral absorption cross sections of actinides (OSMOSE program), of new absorbers (OCEAN program) and also for fission Products (CBU program) in thermal, epithermal and fast neutron spectra. (authors)

  10. Neutron and Charged-Particle Induced Cross Sections for Radiochemistry in the Region of Samarium, Europium, and Gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Kelley, K; Dietrich, F S; Bauer, R; Mustafa, M

    2004-11-30

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron and proton induced nuclear reaction cross sections in the mass region of samarium, europium and gadolinium (62 {le} Z {le} 64, 82 {le} N {le} 96).

  11. Evaluation of sodium-23 neutron capture cross section data for the ENDF/B V-III file

    International Nuclear Information System (INIS)

    The evaluation of neutron cross sections of 23Na, material number 1156, for the ENDF/B File is described. Cross sections were evaluated between 10-5 eV and 15 MeV. Experimental data available up to March 1971 were included in the evaluation

  12. Preliminary cross sections for gamma rays produced by interaction of 1 to 40 MeV neutrons with 59Co

    International Nuclear Information System (INIS)

    Data for 46 distinct gamma rays previously obtained at the 20-meter station of the Oak Ridge Electron Linear Accelerator (ORELA) were studied to determine cross sections for 1.0-40.0 MeV neutron interactions with 59Co. Data reduction methods and preliminary cross sections are given in this report. 5 refs., 12 figs., 8 tabs

  13. Generation of the library of neutron cross sections for the Record code of the Fuel Management System (FMS)

    International Nuclear Information System (INIS)

    On the basis of the library structure of the RECORD code a method to generate the neutron cross sections by means of the ENDF-B/IV database and the NJOY code has been developed. The obtained cross sections are compared with those of the current library which was processed using the ENDF-B/III version. (Author)

  14. Neutron cross-sections for advanced nuclear systems. The nTOF project at CERN

    International Nuclear Information System (INIS)

    In 2012, nuclear energy continued to play an important role in global electricity production. Despite a small reduction of the total generating nuclear power capacity after the accident at the Fukushima Daiichi nuclear power plant, a significant growth, between 35% and 100% by 2030, is foreseen in the use of nuclear energy worldwide. The knowledge of a wide variety of nuclear processes is a fundamental prerequisite in nuclear technology, as well as in other field of fundamental and applied Nuclear Physics. In particular, neutron-induced reactions play a key role in the operation of present nuclear reactors as well as in the design of future ones aiming at minimizing nuclear waste, such as Generation-IV reactors, ADS or reactors based on Th/U fuel cycle. The cross sections of a large number of neutron-induced reactions are requested with high accuracy to improve safety and efficiency of current reactors, and for the design of future generation systems. Since 2001 nTOF, an innovative neutron Time-Of-Flight facility, has been operating at CERN with the aim of addressing the needs of nuclear data for basic and applied nuclear Physics. An extensive program on both neutron induced fission and capture reactions has been carried out so far. Thanks to the well suited features of the nTOF neutron beam, such as the high instantaneous neutron flux, the high resolution and the wide energy range covered, from thermal to a few GeV, coupled with state-of-the-art detectors and data acquisition system, it has been possible to collect high accuracy and high resolution neutron cross-section data on a variety of isotopes, many of which radioactive. In particular, important results for nuclear technologies have been obtained on isotopes of U, Pu and minor actinides with long half life. Recently the construction of a new, high-flux measuring station has started. A 25 times higher fluence relative to the existing experimental area will allow to measure isotopes with short half life, as

  15. Scattering cross sections of liquid deuterium for ultracold neutrons: Experimental results and a calculation model

    CERN Document Server

    Döge, Stefan; Müller, Stefan; Morkel, Christoph; Gutsmiedl, Erwin; Geltenbort, Peter; Lauer, Thorsten; Fierlinger, Peter; Petry, Winfried; Böni, Peter

    2015-01-01

    We present scattering cross sections $\\sigma_\\text{scatt}$ of ultracold neutrons (UCN) in liquid deuterium at T = 20.6 K, as recently measured by means of a transmission experiment. The indispensable thorough raw data treatment procedure is explained. A calculation model for coherent and incoherent scattering in liquid deuterium in the hydrodynamic limit based on appropriate physical concepts is provided and shown to ?t the data well. The applicability of the incoherent approximation for UCN scattering in liquid deuterium was tested and found to deliver acceptable results.

  16. Measurement of the absolute values of cross-sections in neutron photoproduction (1962)

    International Nuclear Information System (INIS)

    The absolute values of photoneutrons production cross-sections for the case of intermediate and heavy nuclei (lanthanium, cerium, tantalum, gold, lead and bismuth) are determined with an error of 15 per cent. The results obtained agree with theories in which the giant resonance is explained by the collective motion of the protons against the neutrons. The effect of the nuclear deformation on the shape of the giant resonance is seen in the case of Ta181, it will be possible to determine the quadrupole momenta of deformed nuclei with a good accuracy when we shall increase the statistics of measurements. (author)

  17. Aquelarre. A computer code for fast neutron cross sections from the statistical model

    International Nuclear Information System (INIS)

    A Fortran V computer code for Univac 1108/6 using the partial statistical (or compound nucleus) model is described. The code calculates fast neutron cross sections for the (n, n'), (n, p), (n, d) and (n, α reactions and the angular distributions and Legendre moments.for the (n, n) and (n, n') processes in heavy and intermediate spherical nuclei. A local Optical Model with spin-orbit interaction for each level is employed, allowing for the width fluctuation and Moldauer corrections, as well as the inclusion of discrete and continuous levels. (Author) 67 refs

  18. Fast-neutron elastic-scattering cross sections of elemental tin

    International Nuclear Information System (INIS)

    Broad-resolution neutron-elastic-scattering cross sections of elemental tin are measured from 1.5 to 4.0 MeV. Incident-energy intervals are approx. 50 keV below 3.0 MeV and approx. 200 keV at higher energies. Ten to twenty scattering angles are used, distributed between approx. 20 and 1600. The experimental results are used to deduce the parameters of a spherical optical-statistical model and they are also compared with corresponding values given in ENDF/B-V

  19. Neutron-induced fission cross sections of uraniums up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus); Hasegawa, A.

    1998-11-01

    Statistical theory of nuclear reactions, well-proved below 20 MeV, is applied for {sup 235}U and {sup 238}U fission data analysis up to {approx}40 MeV. It is shown that measured data could be reproduced. Chance structure of measured fission cross section is provided, it`s validity is supported by description of data for competing (n,xn)-reactions. Role of fissility of target nucleus is addressed. It seems that gap in incident neutron energy interval of 20 MeV - 50 MeV, below which evaluation approaches are well-developed, and above which simplified statistical approaches are valid, could be covered. (author)

  20. Total cross sections for neutron scattering from few nucleon systems. I. Measurements.

    Science.gov (United States)

    Abfalterer, W. P.; Bateman, F. B.; Dietrich, F. S.; Elster, Ch.; Finlay, R. W.; Glöckle, W.; Golak, J.; Haight, R. C.; Hüber, D.; Morgan, G. L.; Witala, H.

    1998-04-01

    We have recently measured neutron total cross sections for hydrogen and the total cross section difference for deuterium-hydrogen (d-h) over a wide energy range (approximately 10-600 MeV projectile energy). These measurements were made by an attenuation technique at the LANSCE/WNR facility using samples of D_2O, H_2O, C_8H_18, and CH2 with a technique similar to that applied in Ref. [1]. The results for d-h are in significant disagreement with previous measurements of this quantity (up to 9% near 80 MeV). The results have been used to test the Faddeev description of the n+d total cross section between 10 and 300 MeV as reported in the following abstract. [1mm] [1] R.W. Finlay et al., Phys. Rev. C47, 237 (1993) [2mm] ^ This work is supported in part by the U.S. Department of Energy under Contracts W-7405-ENG-48 (LLNL), W-7405-ENG-36 (LANL), and DE-FG02-93ER40756 (Ohio U.), the Deutsche Forschungsgemeinschaft (DFG), the Ohio Supercomputer Center (OSC) and the HLRZ Jülich.

  1. Fast-neutron total and scattering cross sections of 58Ni

    International Nuclear Information System (INIS)

    Neutron total cross sections of 58Ni were measured at 25 keV intervals from 0.9 to 4.5 MeV with 50 to 100 keV resolutions. Attention was given to self-shielding corrections to the observed total cross sections. Differential elastic- and inelastic-scattering cross sections were measured at 50 keV intervals from 1.35 to 4.0 MeV with 50 to 100 keV resolutions. Inelastic excitation of levels at 1.458 +- 0.009, 2.462 +- 0.010, 2.791 +- 0.015, 2.927 +- 0.012 and 3.059 +- 0.025 MeV was observed. The experimental results were interpreted in terms of optical-statistical and coupled-channels models. A spherical optical-statistical model was found generally descriptive of an energy-average of the experimental results. However, detailed considerations suggested significant contributions from direct-vibrational interactions, particularly associated with the excitation of the first 2+ level

  2. Neutron cross sections of 28 fission product nuclides adopted in JENDL-1

    International Nuclear Information System (INIS)

    This is the final report concerning the evaluated neutron cross sections of 28 fission product nuclides adopted in the first version of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nuclides were selected as being most important for fast reactor calculations, and are 90Sr, 93Zr, 95Mo, 97Mo, 99Tc, 101Ru, 102Ru, 103Rh, 104Ru, 105Pd, 106Ru, 107Pd, 109Ag, 129I, 131Xe, 133Cs, 135Cs, 137Cs, 143Nd, 144Ce, 144Nd, 145Nd, 147Pm, 147Sm, 149Sm, 151Sm, 153Eu and 155Eu. The status of the experimental data was reviewed over the whole energy range. The present evaluation was performed on the basis of the measured data with the aid of theoretical calculations. The optical and statical models were used for evaluation of the smooth cross sections. An improved method was developed in treating the multilevel Breit-Wigner formula for the resonance region. Various physical parameters and the level schemes, adopted in the present work are discussed by comparing with those used in the other evaluations such as ENDF/B-IV, CEA, CNEN-2 and RCN-2. Furthermore, the evaluation method and results are described in detail for each nuclide. The evaluated total, capture and inelastic scattering cross sections are compared with the other evaluated data and some recent measured data. Some problems of the present work are pointed out and ways of their improvement are suggested. (author)

  3. Medium modifications of the nucleon-nucleon elastic cross section in neutron-rich intermediate energy HICs

    OpenAIRE

    Li, Qingfeng; Li, Zhuxia; Soff, Sven; Bleicher, Marcus; Stöcker, Horst

    2006-01-01

    Several observables of unbound nucleons which are to some extent sensitive to the medium modifications of nucleon-nucleon elastic cross sections in neutron-rich intermediate energy heavy ion collisions are investigated. The splitting effect of neutron and proton effective masses on cross sections is discussed. It is found that the transverse flow as a function of rapidity, the $Q_{zz}$ as a function of momentum, and the ratio of halfwidths of the transverse to that of longitudinal rapidity di...

  4. Measurements of neutron cross section of the {sup 243}Am(n,{gamma}){sup 244}Am reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The effective thermal neutron cross section of {sup 243}Am(n,{gamma}){sup 244}Am reaction was measured by the activation method. Highly-purified {sup 243}Am target was irradiated in an aluminum capsule by using a research reactor JRR-3M. The tentative effective thermal neutron cross sections are 3.92 b, and 84.44 b for the production of {sup 244g}Am and {sup 244m}Am, respectively. (author)

  5. Statistical Model Analysis of (n, α Cross Sections for 4.0-6.5 MeV Neutrons

    Directory of Open Access Journals (Sweden)

    Khuukhenkhuu G.

    2016-01-01

    Full Text Available The statistical model based on the Weisskopf-Ewing theory and constant nuclear temperature approximation is used for systematical analysis of the 4.0-6.5 MeV neutron induced (n, α reaction cross sections. The α-clusterization effect was considered in the (n, α cross sections. A certain dependence of the (n, α cross sections on the relative neutron excess parameter of the target nuclei was observed. The systematic regularity of the (n, α cross sections behaviour is useful to estimate the same reaction cross sections for unstable isotopes. The results of our analysis can be used for nuclear astrophysical calculations such as helium burning and possible branching in the s-process.

  6. Statistical Model Analysis of (n, α) Cross Sections for 4.0-6.5 MeV Neutrons

    Science.gov (United States)

    Khuukhenkhuu, G.; Odsuren, M.; Gledenov, Y. M.; Zhang, G. H.; Sedysheva, M. V.; Munkhsaikhan, J.; Sansarbayar, E.

    2016-02-01

    The statistical model based on the Weisskopf-Ewing theory and constant nuclear temperature approximation is used for systematical analysis of the 4.0-6.5 MeV neutron induced (n, α) reaction cross sections. The α-clusterization effect was considered in the (n, α) cross sections. A certain dependence of the (n, α) cross sections on the relative neutron excess parameter of the target nuclei was observed. The systematic regularity of the (n, α) cross sections behaviour is useful to estimate the same reaction cross sections for unstable isotopes. The results of our analysis can be used for nuclear astrophysical calculations such as helium burning and possible branching in the s-process.

  7. Thermal-neutron cross sections and resonance integrals of 138Ba and 141Pr using Am-Be neutron source

    Science.gov (United States)

    Panikkath, Priyada; Mohanakrishnan, P.

    2016-09-01

    The thermal-neutron capture cross sections and resonance integrals of 138Ba(n, γ)139Ba and 141Pr(n, γ)142Pr were measured by activation method using an isotopic Am-Be neutron source. The estimations were with respect to that of 55Mn(n, γ)56Mn and 197Au(n, γ)198Au reference monitors. The measured thermal-capture cross section of 138 Ba with respect to 55 Mn is 0.410±0.023 b and with respect to 197 Au is 0.386±0.019 b. The measured thermal-capture cross section of 141 Pr with respect to 55 Mn is 11.36±1.29 b and with respect to 197 Au is 10.43±1.14 b. The resonance integrals for 138 Ba are 0.380±0.033 b (55 Mn) and 0.364±0.027 b (197 Au) and for 141 Pr are 21.05±2.88 b (55 Mn) and 15.27±1.87 b (197 Au). The comparison between the present measurements and various reported values are discussed. The cross sections corresponding to the selected isotopes are measured using an Am-Be source facility for the first time.

  8. Neutron Capture and Total Cross Section Measurements and Resonance Parameters of Gadolinium

    International Nuclear Information System (INIS)

    Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic Institute (RPI) linac facility using metallic and liquid Gd samples. The liquid samples were isotopically-enriched in either 155Gd or 157Gd. The capture measurements were made at the 25-m flight station with a multiplicity-type capture detector, and the transmission measurements were performed at 15- and 25-m flight stations with 6Li glass scintillation detectors. The multilevel R-matrix Bayesian code SAMMY was used to extract resonance parameters. Among the significant findings are the following. The neutron width of the largest resonance in Gd, at 0.032 eV in 157Gd, has been measured to be (9 ± 1)% smaller than that given in ENDF/B-VI updated through release 8. The thermal (2200 m/s) capture cross section of 157Gd has been measured to be 11% smaller than that calculated from ENDF. The other major thermal resonance, at 0.025 eV in 155Gd, did not display a significant deviation from the thermal capture cross section given by ENDF. In the epithermal region, the analysis provided here represents the most extensive to date. Twenty eight new resonances are proposed and other resonances previously identified in the literature have been revisited. The assignment of resonances within regions of complicated structure incorporated the observations of other researchers, particularly on the six occasions where ENDF resonances are recommended to be removed. The poor match of the ENDF parameters to the current data is significant, and substantial improvement to the understanding of gadolinium cross sections is presented, particularly above 180 eV where the ENDF resolved region for 155Gd ends

  9. Fast-neutron total and scattering cross sections of 107Ag in the MeV region

    International Nuclear Information System (INIS)

    Neutron total cross sections are measured from 0.25 to 4.5 MeV at intervals of less than or approx. = to 10 keV. Neutron differential elastic- and inelastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 0.2 MeV. Cross sections for scattering into more than 20 energy groups are determined. Cross sections calculated from an optical-statistical model are in quantitative agreement with measured neutron total and elastic-scattering cross sections and in qualitative agreement with measured neutron inelastic-scattering cross sections. In the context of this model, significant dependence of the inelastic-scattering process on parity and/or deformation is not in evidence. The interpretation of the observed neutron inelastic-neutron-scattering results is consistent with previous reported J/sup π/ assignments and the systematics of nuclear-level-densities. 29 references

  10. Total neutron cross-sections for rare isotopes using a digital-signal-processing technique: Case study {sup 48}Ca

    Energy Technology Data Exchange (ETDEWEB)

    Shane, R. [Department of Physics, Washington University, Campus Box 1134, St. Louis, MO 63130 (United States); Charity, R.J.; Elson, J.M. [Department of Chemistry, Washington University, Campus Box 1134, St. Louis, MO 63130 (United States); Sobotka, L.G., E-mail: lgs@wustl.ed [Department of Physics, Washington University, Campus Box 1134, St. Louis, MO 63130 (United States); Department of Chemistry, Washington University, Campus Box 1134, St. Louis, MO 63130 (United States); Devlin, M.; Fotiades, N.; O' Donnell, J.M. [LANSCE Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-03-11

    A digital-signal-processing method was developed and used to measure the total neutron cross-sections of {sup 48}Ca from 15 to 300 MeV. This technique allows for cross-sections to be obtained with high statistical accuracy even for samples that are an order of magnitude smaller than those used with conventional (non-digital) techniques. The isotopic and energy dependence of rare-isotope total neutron cross-sections are of considerable value for extracting the n/p asymmetry dependence of optical-model potentials.

  11. The neutron capture cross section for 99Tc with Feshbach and Weisskopf model

    International Nuclear Information System (INIS)

    The transmutation is one of the famous modes for the nuclear wastes management. It is based on the transformation of the radiotoxic element to the stable one by nuclear reaction.The most important fission product is technetium-99. The 99Tc were confirmed to have highest transmutation priorities in terms of transmutability and long-term radiological risk reduction Its transmutation under a neutron flux in an installation (transmuter) is the process of it artificial transformation into stable nuclides. The neutronic cross sections of the 99Tc (n,γ) 100Tc reaction are calculated with the Feshbach and Weisskopf model outside the resonance region. These values are compared to those evaluated from the nuclear data library ENDF/E IV. The introduction of the normalization factor is necessary to have closer values

  12. The neutron capture cross sections for 99Tc with Feshbach and Weisskopf model

    International Nuclear Information System (INIS)

    Full text: The transmutation is one of the famous modes for the nuclear wastes management. It is based on the transformation of the radio-toxic element to the stable one by nuclear reaction. The most important fission products are technetium-99. The 99Tc were confirmed to have highest transmutation priorities in terms of transmutability and long-term radiological risk reduction. Its transmutation under a neutron flux in an installation (trans-muter) is the process of its artificial transformation into stable nuclides. The neutronic cross sections of the 99Tc(n,γ)100Tc reactions are calculated with the Feshbach and Weisskopf model outside the resonance region. These values are compared to those evaluated from the nuclear data library ENDF/B-IV. The introduction of normalization factor is necessary to have closer values

  13. The neutron capture cross section of the ${s}$-process branch point isotope $^{63}$Ni

    CERN Multimedia

    Neutron capture nucleosynthesis in massive stars plays an important role in Galactic chemical evolution as well as for the analysis of abundance patterns in very old metal-poor halo stars. The so-called weak ${s}$-process component, which is responsible for most of the ${s}$ abundances between Fe and Sr, turned out to be very sensitive to the stellar neutron capture cross sections in this mass region and, in particular, of isotopes near the seed distribution around Fe. In this context, the unstable isotope $^{63}$Ni is of particular interest because it represents the first branching point in the reaction path of the ${s}$-process. We propose to measure this cross section at n_TOF from thermal energies up to 500 keV, covering the entire range of astrophysical interest. These data are needed to replace uncertain theoretical predicitons by first experimental information to understand the consequences of the $^{63}$Ni branching for the abundance pattern of the subsequent isotopes, especially for $^{63}$Cu and $^{...

  14. Total cross sections for neutron scattering from few nucleon systems. II. Theoretical considerations.^.

    Science.gov (United States)

    Elster, Ch.; Abfalterer, W. P.; Bateman, F. B.; Dietrich, F. S.; Finlay, R. W.; Glöckle, W.; Golak, J.; Haight, R. C.; Hüber, D.; Morgan, G. L.; Witala, H.

    1998-04-01

    New high precision measurements of the difference in neutron total cross sections of deuterium and hydrogen (d-h) were performed for neutron energies between 10 and 600 MeV. The results are compared to state-of-the-art Faddeev calculations of the n+d total cross section between 10 and 300 MeV, which systematically underpredict the experiment above 100 MeV. This result is not very sensitive to the type of modern NN interaction employed. Further, the convergence of the Faddeev multiple scattering series is demonstrated. We therefore conclude that the Faddeev description is inadequate above 100 MeV projectile energy. We also consider the first and second order terms in the multiple scattering series in the high energy limit to study shadowing effects. [1mm] ^ This work is supported in part by the U.S. Department of Energy under Contracts W-7405-ENG-48 (LLNL), W-7405-ENG-36 (LANL), and DE-FG02-93ER40756 (Ohio U.), the Deutsche Forschungsgemeinschaft (DFG), the Ohio Supercomputer Center (OSC) and the HLRZ Jülich.

  15. A correlated study between effective total macroscopic cross sections and effective energies for neutron beams with continuous spectra

    CERN Document Server

    Kobayashi, H

    1999-01-01

    Two practically useful quantities have been introduced to characterize a continuous-energy-spectrum neutron beam and to describe transmission phenomena of the beam in the field of quantitative neutron radiography. These quantities are the effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section as defined for a monochromatic energy. Four neutron beams have been used to measure ETM cross sections at effective energies of 29.8, 17.2, 9.8 meV, and at the In resonance energy of 1.46 eV. Results are studied as a function of estimated effective energy, where the effective energy was estimated by a beam quality indicator (BQI) which has been proposed recently. Validity of ETM cross sections as a function of the effective energy is discussed and correlated with recent nuclear data.

  16. Neutron Cross Section Processing Methods for Improved Integral Benchmarking of Unresolved Resonance Region Evaluations

    Science.gov (United States)

    Walsh, Jonathan A.; Forget, Benoit; Smith, Kord S.; Brown, Forrest B.

    2016-03-01

    In this work we describe the development and application of computational methods for processing neutron cross section data in the unresolved resonance region (URR). These methods are integrated with a continuous-energy Monte Carlo neutron transport code, thereby enabling their use in high-fidelity analyses. Enhanced understanding of the effects of URR evaluation representations on calculated results is then obtained through utilization of the methods in Monte Carlo integral benchmark simulations of fast spectrum critical assemblies. First, we present a so-called on-the-fly (OTF) method for calculating and Doppler broadening URR cross sections. This method proceeds directly from ENDF-6 average unresolved resonance parameters and, thus, eliminates any need for a probability table generation pre-processing step in which tables are constructed at several energies for all desired temperatures. Significant memory reduction may be realized with the OTF method relative to a probability table treatment if many temperatures are needed. Next, we examine the effects of using a multi-level resonance formalism for resonance reconstruction in the URR. A comparison of results obtained by using the same stochastically-generated realization of resonance parameters in both the single-level Breit-Wigner (SLBW) and multi-level Breit-Wigner (MLBW) formalisms allows for the quantification of level-level interference effects on integrated tallies such as keff and energy group reaction rates. Though, as is well-known, cross section values at any given incident energy may differ significantly between single-level and multi-level formulations, the observed effects on integral results are minimal in this investigation. Finally, we demonstrate the calculation of true expected values, and the statistical spread of those values, through independent Monte Carlo simulations, each using an independent realization of URR cross section structure throughout. It is observed that both probability table

  17. EVALUATION OF NEUTRON CROSS SECTIONS FOR A COMPLETE SET OF Nd ISOTOPES.

    Energy Technology Data Exchange (ETDEWEB)

    KIM,H.; HERMAN, M.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; ROCHMAN, D.; LEE. Y.-O.

    2007-10-29

    Neutron cross sections for a complete set of Nd isotopes, {sup 142,143,144,145,146,147,148,150}Nd, were evaluated in the incident energy range from 10{sup -5} eV to 20 MeV. In the low energy region, including thermal and resolved resonances, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. In the unresolved resonance region we performed additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data. In the fast neutron region, we used the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. The results are compared to the existing nuclear data libraries, including ENDF/B-VI.8, JENDL-3.3 and JEFF-3.1, and to the available experimental data. The new evaluations are suitable for neutron transport calculations and they were adopted by the new evaluated nuclear data file of the United States, ENDF/B-VII.0, released in December 2006.

  18. Measurement of the radiative neutron capture cross section of 206Pb and its astrophysical implications

    CERN Document Server

    Domingo-Pardo, C; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, M; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; Oshima, M; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2007-01-01

    The (n, gamma) cross section of 206Pb has been measured at the CERN n_TOF facility with high resolution in the energy range from 1 eV to 600 keV by using two optimized C6D6 detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture gamma-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched 208Pb sample. The effect of the lower energy cutoff in the pulse height spectra of the C6D6 detectors was carefully corrected via Monte Carlo simulations. Compared to previous 206Pb values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results hav...

  19. Interaction cross section study of the two-neutron halo nucleus 22C

    Science.gov (United States)

    Togano, Y.; Nakamura, T.; Kondo, Y.; Tostevin, J. A.; Saito, A. T.; Gibelin, J.; Orr, N. A.; Achouri, N. L.; Aumann, T.; Baba, H.; Delaunay, F.; Doornenbal, P.; Fukuda, N.; Hwang, J. W.; Inabe, N.; Isobe, T.; Kameda, D.; Kanno, D.; Kim, S.; Kobayashi, N.; Kobayashi, T.; Kubo, T.; Leblond, S.; Lee, J.; Marqués, F. M.; Minakata, R.; Motobayashi, T.; Murai, D.; Murakami, T.; Muto, K.; Nakashima, T.; Nakatsuka, N.; Navin, A.; Nishi, S.; Ogoshi, S.; Otsu, H.; Sato, H.; Satou, Y.; Shimizu, Y.; Suzuki, H.; Takahashi, K.; Takeda, H.; Takeuchi, S.; Tanaka, R.; Tuff, A. G.; Vandebrouck, M.; Yoneda, K.

    2016-10-01

    The interaction cross sections (σI) of the very neutron-rich carbon isotopes 19C, 20C and 22C have been measured on a carbon target at 307, 280, and 235 MeV/nucleon, respectively. A σI of 1.280 ± 0.023 b was obtained for 22C, significantly larger than for 19,20C, supporting the halo character of 22C. A 22C root-mean-squared matter radius of 3.44 ± 0.08 fm was deduced using a four-body Glauber reaction model. This value is smaller than an earlier estimate (of 5.4 ± 0.9 fm) derived from a σI measurement on a hydrogen target at 40 MeV/nucleon. These new, higher-precision σI data provide stronger constraints for assessing the consistency of theories describing weakly bound nuclei.

  20. Neutron total cross-sections and resonance parameters of Mo and Ta

    Indian Academy of Sciences (India)

    A K M Moinul Haque Meaze; K Devan; Y S Lee; Y D Oh; G N Kim; D Son

    2007-02-01

    Experimental results of transmissions for the samples of natural molybdenum with thickness 0.0192 atoms/barn and for the four samples of natural tantalum with thickness 0.0222, 0.0111, 0.0055 and 0.0025 atoms/barn are presented in this work. Measurements were carried out at the Pohang Neutron Facility which consists of a 100 MeV Linac, water-cooled tantalum target, and 12 m flight path length. Effective total cross-sections were extracted from the transmission data, and resonance parameters were obtained by using the code SAMMY. The present measurements were compared with other measurements and with the evaluated nuclear data file ENDF/B-VI.8.

  1. Measurement of capture cross sections of 238U on the filtered keV-neutron beams

    International Nuclear Information System (INIS)

    Capture cross sections for the 238U(n,γ) reaction were measured related to that of the 197Au(n,γ) reaction on the filtered keV-neutron beams at the Dalat reactor using the activation method. Radioactivities of samples after irradiation were measured with HPGe detectors (50 mm2 sensitive area, FWHM = 150 eV for 55Fe and 70 cc volume, FWHM = 2.5 keV at 1332 keV γ-transition of 60Co). The data obtained by the authors were compared with the evaluations in ENDF/B-VI and JEF-2 and also with the results from recent experimental works. (author). 12 refs, 1 fig., 4 tabs

  2. Investigations of neutron characteristics for salt blanket models; integral fission cross section measurements of neptunium, plutonium, americium and curium isotopes

    International Nuclear Information System (INIS)

    Neutron characteristics of salt blanket micromodels containing eutectic mixtures of sodium, zirconium, and uranium fluorides were measured on FKBN-2M, BIGR and MAKET facilities. The effective fission cross sections of neptunium, plutonium, americium, and curium isotopes were measured on the neutron spectra formed by micromodels. (author)

  3. Measurement of thermal neutron cross section for {sup 241}Am(n,f) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Katsuhei; Yamamoto, Shuji; Fujita, Yoshiaki [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Miyoshi, Mitsuharu; Kimura, Itsuro; Kanno, Ikuo; Shinohara, Nobuo

    1997-03-01

    Making use of a standard neutron spectrum field with a pure Maxwellian distribution, the thermal neutron cross section for the {sup 241}Am(n,f) reaction has been measured relative to the reference value of 586.2b for the {sup 235U}(n,f) reaction. For the present measurement, electrodeposited layers of {sup 241}Am and {sup 235}U have been employed as back-to-back type double fission chambers. The present result at neutron energy of 0.0253 eV is 3.15 {+-} 0.097b. The ENDF/B-VI data is in good agreement with the present value, while the JENDL-3.2 data is lower by 4.2%. The evaluated data in JEF-2.2 and by Mughabghab are higher by 0.9% and 1.6%, respectively than the present result. The ratios of the earlier experimental data to the present value are distributed between 0.89 and 1.02. (author)

  4. New Standard Evaluated Neutron Cross Section Libraries for the GEANT4 Code and First Verification

    CERN Document Server

    Mendoza, Emilio; Koi, Tatsumi; Guerrero, Carlos

    2014-01-01

    The Monte Carlo simulation of the interaction of neutrons with matter relies on evaluated nuclear data libraries and models. The evaluated libraries are compilations of measured physical parameters (such as cross sections) combined with predictions of nuclear model calculations which have been adjusted to reproduce the experimental data. The results obtained from the simulations depend largely on the accuracy of the underlying nuclear data used, and thus it is important to have access to the nuclear data libraries available, either of general use or compiled for specific applications, and to perform exhaustive validations which cover the wide scope of application of the simulation code. In this paper we describe the work performed in order to extend the capabilities of the GEANT4 toolkit for the simulation of the interaction of neutrons with matter at neutron energies up to 20 MeV and a first verification of the results obtained. Such a work is of relevance for applications as diverse as the simulation of a n...

  5. The capture cross sections of the neon isotopes and the s-process neutron balance

    International Nuclear Information System (INIS)

    The neutron capture cross sections of the three stable neon isotopes have been measured by the time-of-flight method in the energy range from 5 to 200 keV, using hydrogen free fast liquid scintillator detectors and the Maier-Leibnitz pulse height weighting technique. As a result it was found that neutron absorption by the light elements, from 20Ne to 56Fe, is dominated not by 22Ne but by 25Mg. The condition that as many neutrons should be produced as are absorbed has led to the conclusion that at least 80% of the 22Ne must undergo the (α,n) reaction, which implies that less than 20% can undergo the (α,γ) reaction. Therefore the (α,n) reaction rate must be at least 4 times faster than the (α,γ) rate. An inspection of these reaction rates as a function of temperature shows that this condition can be satisfied only for T > 3.2 108 K, or kT > 28 keV. (orig./HSI)

  6. 232Th and 238U neutron emission cross section calculations and analysis of experimental data

    International Nuclear Information System (INIS)

    In this study, pre-equilibrium neutron-emission spectra produced by (n,xn) reactions on nuclei 232Th and 238U have been calculated. Angle-integrated cross sections in neutron induced reactions on targets 232Th and 238U have been calculated at the bombarding energies up to 18 MeV. We have investigated multiple pre-equilibrium matrix element constant from internal transition for 232Th (n,xn) neutron emission spectra. In the calculations, the geometry dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. In addition, we have described how multiple pre-equilibrium emissions can be included in the Feshbach-Kerman-Koonin (FKK) fully quantum-mechanical theory. By analyzing (n,xn) reaction on 232Th and 238U, with the incident energy from 2 Me V to 18 Me V, the importance of multiple pre-equilibrium emission can be seen cleady. All calculated results have been compared with experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other

  7. Calculation of the neutron induced fission cross-section of 233Pa up to 20 MeV

    International Nuclear Information System (INIS)

    Since very recently, direct measurements of the 233Pa(n,f) cross-section are available in the energy range from 1.0 to 8.5 MeV. This has stimulated a new, self-consistent, neutron cross-section evaluation for the n+233Pa system, in the incident neutron energy range 0.01-20 MeV. Since higher fission chances are involved also the lighter Pa-isotopes had to be re-evaluated in a consistent manner. The results are quite different compared to earlier evaluation attempts. Since 233Pa is a key isotope in the thorium based fuel cycle the quality of its reaction cross-sections is important for the modeling of future advanced fuel and reactor concepts. The present status of the evaluated libraries is that they differ by a factor of two in the absolute fission cross-section and also in the threshold energy value

  8. Integral test of neutron cross section data for future reactor materials through measurement and analysis of neutron spectra

    International Nuclear Information System (INIS)

    In order to assess the cross section data for future reactor materials, such as molybdenum, niobium, titanium, lithium and fluorine, the angular neutron spectra in test piles of these materials or their chemical compounds have been measured in the energy range from a few keV to a few MeV by the linac time-of-flight method. The results have been compared with those theoretically calculated from the evaluated cross section data in such as JENDL-2 (or JENDL-1, JENDL-3PR1) and ENDF/B-IV. For both of molybdenum and niobium, it has been found that the energy distribution of inelastically scattered neutrons plays an important role in the analysis, and the JENDL library gives better predictions of spectrum shapes than ENDF/B-IV for both cases. In the case of niobium, however, it appears that the values of inelastic scattering cross section in JENDL-2 are too small around 2 MeV. It has been also found for niobium that the cross section data below 100 keV in ENDF/B-IV are inadequate. In a titanium pile, a discrepancy between the measured spectrum and the calculated one from ENDF/B-IV has been found in the energy range from about 60 keV to a few 100 keV. In order to investigate the cause of this discrepancy, the total cross sections for titanium have been measured by the transmission method. In the case of lithium, the discrepancy between the measured and calculated spectra is considerably reduced by adopting the angular distribution for 7Li from ENDF/B-IV above about 500 keV. In the case of fluorine, spatial distributions of neutrons and X-rays have been also measured in both piles by the activation method to estimate the influence of photoneutrons generated in the sample material on the neutron distribution, and it has been found that their influence below 1 MeV is not so large as is necessary to be taken into account for the present assessment. (J.P.N)

  9. Theoretical Analysis of Neutron Double-Differential Cross Section of n+11B at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Shang

    2003-01-01

    A new reaction model for light nuclei is proposed to analyze the measured data, especially for the doubledifferential cross sections. In this paper the calculation with this model is employed to analyze measurements of the total outgoing neutron double-differential cross sections for n+11B reactions at En = 14.2 MeV. The representation of the double-differential cross sections of the second emitted particles is given in detail. The calculation results indicate that the recoil effect in light nuclear reaction is essentially important. The reaction channels are discussed in detail.

  10. Neutron inelastic-scattering cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu

    International Nuclear Information System (INIS)

    Differential-neutron-emission cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. 232Th, 233U, 235U and 238U inelastic-scattering values, poor agreement is observed for 240Pu, and a serious discrepancy exists in the case of 239Pu

  11. Photoneutron cross sections measurements in 9Be, 13C e 17O with thermal neutron capture gamma-rays

    International Nuclear Information System (INIS)

    Photoneutron cross sections measurements of 9Be, 13C and 17O have been obtained in the energy interval between 1,6 and 10,8 MeV, using neutron capture gamma-rays with high resolution in energy (3 a 21 eV), produced by 21 target materials, placed inside a tangential beam port, near the core of the IPEN/CNEN-SP IEA-R1 (5 MW) research reactor. The samples have been irradiated inside a 4π geometry neutron detector system 'Long Counter', 520,5 cm away from the capture target. The capture gamma-ray flux was determined by means of the analysis of the gamma spectrum obtained by using a Ge(Li) solid-state detector (EG and G ORTEC, 25 cm3, 5%), previously calibrated with capture gamma-rays from a standard target of Nitrogen (Melamine). The neutron photoproduction cross section has been measured for each target capture gamma-ray spectrum (compound cross section). A inversion matrix methodology to solve inversion problems for unfolding the set of experimental compound cross sections, was used in order to obtain the cross sections at specific excitation energy values (principal gamma line energies of the capture targets). The cross sections obtained at the energy values of the principal gamma lines were compared with experimental data reported by other authors, with have employed different gamma-ray sources. A good agreement was observed among the experimental data in this work with reported in the literature. (author)

  12. Fast neutron cross section measurements. Final technical report, March 1, 1987--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, G.F.

    1997-06-01

    The time-of-flight technique was used with the ring scattering geometry in a laboratory with low neutron scattering background to measure the angular distributions of the cross sections for elastic and inelastic scattering of 14 MeV neutrons in natural chromium, iron, nickel, and niobium. Specifically for inelastic scattering included were: the 1.43 MeV and 4.56 MeV levels of {sup 52}Cr, the 0.85 MeV level, and (2.94-3.12) MeV and (4.46-4.51) MeV level groups of {sup 56}Fe, the 1.33 MeV level of {sup 60}Ni combined with the 1.45 MeV level of {sup 58}Ni, and the 4.48 MeV level of {sup 58}Ni. Pulses of neutrons with time width of 0.9-1.1 ns were produced via the {sup 3}H(d,n){sup 4}He reaction in a 150 keV Cockcroft-Walton linear accelerator, with average intensities of 9x10{sup 8} n/s. The energy of the incident neutrons was between 14.75 MeV (at 16{degree}) and 13.48 MeV (at 160{degree}). High purity scattering ring samples were used. The scattering angles ranged from {approx}16{degree} to {approx}150{degree}, for iron, chromium, and nickel, and from {approx}16{degree} to {approx}160{degree} for niobium, with a typical step of {approx}10{degree}. High purity ring samples were used.

  13. Measurement of the neutron total cross section of sodium from 32 keV to 37 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D.C.; Harvey, J.A.; Hill, N.W.

    1976-10-01

    The neutron transmission through a 8.1-cm sample of pure sodium has been measured for neutron energies between 32.5 keV and 37.4 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons, which were detected at the 200-m flight path by a NE-110 proton recoil detector. The experimental results are tabulated and compared with the total cross section in the ENDF/B-IV file for sodium.

  14. Theoretical Analysis of Neutron Double-differental Cross Section of n+10B at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Having very large neutron absorption cross-section at low energies, 10B has long been selected as theshielding material in nuclear engineering. In the reactions of n+10B there are many partial reactionchannels to be opened even at incident neutron energies of 14 MeV Since the new approach fordescription of neutron induced light nucleus reaction was proposed in 1999, many experimental data,

  15. Integral cross section measurements of a few threshold reactions induced by Am/Be neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Md. Shuza; Hossain, Syed Mohammad; Rumman-Uz-Zaman, Md. [Atomic Energy Research Establishment, Dhaka (Bangladesh). Institute of Nuclear Science and Technology (INST); Spahn, Ingo; Qaim, Syed M. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Neurowissenschaften und Medizin (INM), Nuklearchemie (INM-5); Rakib-Uz-Zaman, Md. [Rajshahi Univ. (Bangladesh). Dept. of Applied Chemistry and Chemical Engineering

    2015-07-01

    Integral cross sections of the reactions {sup 46}Ti(n,p){sup 46}Sc, {sup 47}Ti(n,p){sup 47}Sc, {sup 48}Ti(n,p){sup 48}Sc, {sup 60}Ni(n,p){sup 60}Co and {sup 64}Zn(n,p){sup 64}Cu were measured with fast neutrons (E{sub n} > 1.5 MeV) from an Am/Be source. The results were compared with data calculated using the neutron spectral distribution and the excitation function of each reaction given in the data libraries ENDF/B-VII.0, IRDF-2002, JEFF-3.2 and JENDL-4.0. In general, the integral measurement and the integrated value agreed within ±4%, except for the {sup 46}Ti(n,p){sup 46}Sc reaction where JEFF-3.2 shows a deviation of 7% and the {sup 60}Ni(n,p){sup 60}Co reaction where ENDF/B-VII.0 and IRDF-2002 exhibit deviations upto 8%.

  16. Review and Assessment of Neutron Cross Section and Nubar Covariances for Advanced Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Maslov,V.M.; Oblozinsky, P.; Herman, M.

    2008-12-01

    In January 2007, the National Nuclear Data Center (NNDC) produced a set of preliminary neutron covariance data for the international project 'Nuclear Data Needs for Advanced Reactor Systems'. The project was sponsored by the OECD Nuclear Energy Agency (NEA), Paris, under the Subgroup 26 of the International Working Party on Evaluation Cooperation (WPEC). These preliminary covariances are described in two recent BNL reports. The NNDC used a simplified version of the method developed by BNL and LANL that combines the recent Atlas of Neutron Resonances, the nuclear reaction model code EMPIRE and the Bayesian code KALMAN with the experimental data used as guidance. There are numerous issues involved in these estimates of covariances and it was decided to perform an independent review and assessment of these results so that better covariances can be produced for the revised version in future. Reviewed and assessed are uncertainties for fission, capture, elastic scattering, inelastic scattering and (n,2n) cross sections as well as prompt nubars for 15 minor actinides ({sup 233,234,236}U, {sup 237}Np, {sup 238,240,241,242}Pu, {sup 241,242m,243}Am and {sup 242,243,244,245}Cm) and 4 major actinides ({sup 232}Th, {sup 235,238}U and {sup 239}Pu). We examined available evaluations, performed comparison with experimental data, taken into account uncertainties in model parameterization and made use state-of-the-art nuclear reaction theory to produce the uncertainty assessment.

  17. Neutron Cross section Covariances in the Resonance region: 50,53Cr, 54,57Fe and 60Ni

    Energy Technology Data Exchange (ETDEWEB)

    Oblozinsky, P.; Cho,Y.-S.; Mattoon,C.M.; Mughabghab,S.F.

    2010-11-23

    We evaluated covariances in the neutron resonance region for capture and elastic scattering cross sections on minor structural materials, {sup 50,53}Cr, {sup 54,57}Fe and {sup 60}Ni. Use was made of the recently developed covariance formalism based on kernel approximation along with data in the Atlas of Neutron Resonances. Our results of most interest for advanced fuel cycle applications, elastic scattering cross section uncertainties at energies around 100 keV, are on the level of about 7-10%.

  18. Characterization of an INVS Model IV Neutron Counter for High Precision ($\\gamma,n$) Cross-Section Measurements

    CERN Document Server

    Arnold, C W; Karwowski, H J; Rich, G C; Tompkins, J R; Howell, C R

    2010-01-01

    A neutron counter designed for assay of radioactive materials has been adapted for beam experiments at TUNL. The cylindrical geometry and 64% maximum efficiency make it well suited for ($\\gamma,n$) cross-section measurements near the neutron emission threshold. A high precision characterization of the counter has been made using neutrons from several sources. Using a combination of measurements and simulations, the absolute detection efficiency of the neutron counter was determined to an accuracy of $\\pm$ 3% in the neutron energy range between 0.1 and 1 MeV. It is shown that this efficiency characterization is generally valid for a wide range of targets.

  19. Evaluation of HYLIFE-II and Sombrero using 175- and 566-group neutron transport and activation cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Latkowski, Jeffery F. E-mail: latkowski1@llnl.gov; Cullen, Dermott E.; Sanz, Javier

    2000-11-01

    Recent modifications to the TART Monte Carlo neutron and photon transport code allow enable calculation of 566-group neutron spectra. This expanded group structure represents a significant improvement over the 50- and 175-group structures that have been previously available. To support use of this new capability, neutron activation cross-section libraries have been created in the 175- and 566-group structures starting from the FENDL/A-2.0 pointwise data. Neutron spectra have been calculated for the first walls of the HYLIFE-II and Sombrero inertial fusion energy power plant designs and have been used in subsequent neutron activation calculations. The results obtained using the two different group structures are compared with each other as well as to those obtained using a 175-group version of the EAF3.1 activation cross-section library.

  20. Analysis of Neutron Double-Differential Cross Sections for n + 12C Reaction Below 30 MeV

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the light nucleus reaction model (Nucl. Sci. Eng. l33 (1999) 218), four aspects (neutron incident energy region, reaction channel analysis, the renewed level schemes and the optical model parameters) of n+12 C reaction are improved to calculate total outgoing neutron double-differential cross sections with modified LUNF code below 30 MeV. The calculated results agree fairly well with the experimental data at En = 14.1 MeV and 18 MeV. The analysis shows that the pre-equilibrium mechanism, which is exactly considered the conservation of energy, momentum and parity, dominates the whole reaction process. The contribution of the neutron emission from 5He to total energyangular spectra is also considered properly. This modified LUNF code will be a useful tool to set up the file of neutron double-differential cross sections below 30 MeV in the neutron evaluation nuclear data library.

  1. The thermal neutron absorption cross-sections, resonance integrals and resonance parameters of silicon and its stable isotopes

    International Nuclear Information System (INIS)

    The data available up to the end of November 1968 on the thermal neutron absorption cross-sections, resonance absorption integrals, and resonance parameters of silicon and its stable isotopes are collected and discussed. Estimates are given of the mean spacing of the energy levels of the compound nuclei near the neutron binding energy. It is concluded that the thermal neutron absorption cross-section and resonance absorption integral of natural silicon are not well established. The data on these two parameters are somewhat correlated, and three different assessments of the resonance integral are presented which differ over-all by a factor of 230. Many resonances have been detected by charged particle reactions which have not yet been observed in neutron cross-section measurements. One of these resonances of Si28, at En = 4 ± 5 keV might account for the large resonance integral which is derived, very uncertainly, from integral data. The principal source of the measured resonance integral of Si30 has not yet been located. The thermal neutron absorption cross-section of Si28 appears to result mainly from a negative energy resonance, possibly the resonance at En = - 59 ± 5 keV detected by the Si28 (d,p) reaction. (author)

  2. Measurement of neutron-induced activation cross-sections using spallation source at JINR and neutronic validation of the Dubna code

    Indian Academy of Sciences (India)

    Manish Sharma; V Kumar; H Kumawat; J Adam; V S Barashenkov; S Ganesan; S Golovatiouk; S K Gupta; S Kailas; M I Krivopustov; H S Palsania; V Pronskikh; V M Tsoupko-Sitnikov; N Vladimirova; H Westmeier; W Westmeier

    2007-02-01

    A beam of 1 GeV proton coming from Dubna Nuclotron colliding with a lead target surrounded by 6 cm paraffin produces spallation neutrons. A Th-foil was kept on lead target (neutron spallation source) in a direct stream of neutrons for activation and other samples of 197Au, 209Bi, 59Co, 115In and 181Ta were irradiated by moderated beam of neutrons passing through 6 cm paraffin moderator. The gamma spectra of irradiated samples were analyzed using gamma spectrometry and DEIMOS software to measure the neutron cross-section. For this purpose neutron fluence at the positions of samples is also estimated using PREPRO software. The results of cross-sections for reactions 232Th(, ), 232Th(, 2), 197Au(, ), 197Au(, ), 197Au(, ), 59Co(, ), 59Co(, ), 181Ta(, ) and 181Ta(, ) are given in this paper. Neutronics validation of the Dubna Cascade Code is also done using cross-section data by other experiments.

  3. Sensitivity coefficients for the 238U neutron-capture shielded-group cross sections

    International Nuclear Information System (INIS)

    In the unresolved resonance region cross sections are represented with statistical resonance parameters. The average values of these parameters are chosen in order to fit evaluated infinitely dilute group cross sections. The sensitivity of the shielded group cross sections to the choice of mean resonance data has recently been investigated for the case of 235U and 239Pu by Ganesan and by Antsipov et al; similar sensitivity studies for 238U are reported

  4. Neutron capture cross sections of the krypton isotopes and the s-process branching at 79Se

    International Nuclear Information System (INIS)

    The input data for an analysis of the s-process branching at 79Se have been significantly improved. The neutron capture cross sections for the stable krypton isotopes (except 86Kr) were measured between 3 and 240 keV neutron energy. In addition, statistical model calculations of the (n,γ)-cross sections for all isotopes involved in this branching were performed. With these data and with other experimental results from literature a recommended set of Maxwellian average cross sections was established in the mass region 77< A<85. The relevant decay parameters of the involved unstable nuclei and the parameters for the s-process model are discussed as well. On this basis the following aspects are investigated: the temperature during s-process, the decomposition into s- and r-process contributions and the solar krypton abundance. (orig.)

  5. Cross Sections for Neutron-induced Reactions on Actinide Targets Extracted from Surrogate Experiments: A Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Lesher, S R; Scielzo, N D; Thompson, I J; Younes, W

    2009-10-01

    The Surrogate nuclear reactions method, an indirect approach for determining cross sections for compound-nuclear reactions involving difficult-to-measure targets, is reviewed. Focusing on cross sections for neutron-induced reactions on actinides, we review the successes of past and present applications of the method and assess its uncertainties and limitations. The approximations used in the analyses of most experiments work reasonably well for (n,f) cross sections for neutron energies above 1-2 MeV, but lead to discrepancies for low-energy (n,f) reactions, as well as for (n,{gamma}) applications. Correcting for some of the effects neglected in the approximate analyses leads to improved (n,f) results. We outline steps that will further improve the accuracy and reliability of the Surrogate method and extend its applicability to reactions that cannot be approached with the present implementation of the method.

  6. Computer calculation of neutron cross sections with Hauser-Feshbach code STAPRE incorporating the hybrid pre-compound emission model

    International Nuclear Information System (INIS)

    Computer codes incorporating advanced nuclear models (optical, statistical and pre-equilibrium decay nuclear reaction models) were used to calculate neutron cross sections needed for fusion reactor technology. The elastic and inelastic scattering (n,2n), (n,p), (n,n'p), (n,d) and (n,γ) cross sections for stable molybdenum isotopes Mosup(92,94,95,96,97,98,100) and incident neutron energy from about 100 keV or a threshold to 20 MeV were calculated using the consistent set of input parameters. The hydrogen production cross section which determined the radiation damage in structural materials of fusion reactors can be simply deduced from the presented results. The more elaborated microscopic models of nuclear level density are required for high accuracy calculations

  7. MENDF71x. Multigroup Neutron Cross Section Data Tables Based upon ENDF/B-VII.1

    Energy Technology Data Exchange (ETDEWEB)

    Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parsons, Donald Kent [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gardiner, Steven J. [Univ. of California, Davis, CA (United States); Gray, Mark Girard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lee, Mary Beth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); White, Morgan Curtis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-17

    A new multi-group neutron cross section library has been released along with the release of NDI version 2.0.20. The library is named MENDF71x and is based upon the evaluations released in ENDF/B-VII.1 which was made publicly available in December 2011. ENDF/B-VII.1 consists of 423 evaluations of which ten are excited states evaluations and 413 are ground state evaluations. MENDF71x was created by processing the 423 evaluations into 618-group, downscatter only NDI data tables. The ENDF/B evaluation files were processed using NJOY version 99.393 with the exception of 35Cl and 233U. Those two isotopes had unique properties that required that we process the evaluation using NJOY version 2012. The MENDF71x library was only processed to room temperature, i.e., 293.6 K. In the future, we plan on producing a multi-temperature library based on ENDF/B-VII.1 and compatible with MENDF71x.

  8. Sensitivity of tungsten neutron cross sections to target band mixing and ν6 deformation

    International Nuclear Information System (INIS)

    It is shown that insertion of a deformation parameter ν6 in coupled channels calculations may be necessary for proper predictions of the neutron total cross sections (sigma/sub T/) at incident energies below approx.700 keV. This is illustrated in the present work with the sigma/sub T/ measurements of Whalen et al. on the /sup 182,184,186/W isotopes. In a previous report it has been established that these data could not be well reproduced using coupled channel calculations involving only ν2 and ν4 deformations. It is shown presently that this discrepancy can be removed if, provided that self-shielding corrections to these measurements are made, a small deformation parameter ν6 is considered in coupled channel analyses. As the W isotopes are lying at the rotational edge of the A = 190--200 transitional mass region, it is also emphasized that band mixing effects on the model predictions might be of some importance. These effects have been investigated for /sup 182,184,186/W as well as for 183W using realistic collective wave functions

  9. Comparison of neutron cross sections for selected fission products and isotopic composition analyses with burnup

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. H.; Gil, C. S.; Kim, J. D.; Jang, J. H.; Lee, Y. D. [KAERI, Taejon (Korea)

    2003-10-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI-BNL international collaboration have been compared with the ENDF/B-VI release 7. Also, the influence of the new evaluations on isotopic compositions of the fission products as a function of burnup has been analyzed through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69 group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including new evaluations in resonance region covering thermal region, and ENDF/B-VII expected including those in upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows maximum difference of 4.78% compared to ENDF/B-VI.7. However, the isotopic compositions of all fission products calculated with ENDF/B-VII shows no differences compared to ENDF/B-VI.7.

  10. Comparisons of Neutron Cross Sections and Isotopic Composition Calculations for Fission-Product Evaluations

    Science.gov (United States)

    Kim, Do Heon; Gil, Choong-Sup; Chang, Jonghwa; Lee, Yong-Deok

    2005-05-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI (Korea Atomic Energy Research Institute)-BNL (Brookhaven National Laboratory) international collaboration have been compared with ENDF/B-VI.7. Also, the influence of the new evaluations on the isotopic composition calculations of the fission products has been estimated through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69-group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including the new evaluations in the resonance region covering the thermal region, and the expected ENDF/B-VII including those in the upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows a maximum difference of 5.02% compared to ENDF/B-VI.7. However, the isotopic compositions of all the fission products calculated with the expected ENDF/B-VII show no differences when compared to ENDF/B-VI.7 for the thermal reactor benchmark cases.

  11. Large-scale QRPA calculation of E1-strength and its impact on the neutron capture cross section

    CERN Document Server

    Goriely, S

    2002-01-01

    Large-scale QRPA calculations of the E1-strength are performed as a first attempt to microscopically derive the radiative neutron capture cross sections for the whole nuclear chart. A folding procedure is applied to the QRPA strength distribution to take the damping of the collective motion into account. It is shown that the resulting E1-strength function based on the SLy4 Skyrme force is in close agreement with photoabsorption data as well as the available experimental E1-strength at low energies. The increase of the E1-strength at low energies for neutron-rich nuclei is qualitatively analyzed and shown to affect the corresponding radiative neutron capture cross section significantly. A complete set of E1-strength function is made available for practical applications in a table format for all 7neutron drip lines.

  12. Neutron cross sections of 122Te, 123Te, and 124Te between 1 and 60 keV

    International Nuclear Information System (INIS)

    The currently favored s process scenario of helium shell burning in low mass stars involves a range of thermal energies from kT=12 to 25 keV with most of the neutron exposure taking place at low temperatures. Therefore, differential cross sections are required down to the region of resolved resonances for the reliable determination of the Maxwellian-averaged cross sections typical of the stellar plasma. This work deals with the neutron capture cross sections of the important s only isotopes 122Te, 123Te, and 124Te, which were measured between 1 and 60 keV neutron energy with a setup of Moxon-Rae detectors. The systematic uncertainties achieved in this experiment are ∼5%, but statistical uncertainties are smaller than 2%. In addition to the Moxon-Rae detectors, the setup includes a 6Li glass detector which could be used to determine the total neutron cross sections simultaneously. These results represent the first set of experimental data in this energy range

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

    Science.gov (United States)

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

    2015-10-01

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

  14. R-Matrix Evaluation of {sup 16}O neutron cross sections up to 6.3 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.; Leal, L.C.; Larson, N.M.; Spencer, R.R.; and Wright, R.Q.

    2000-08-01

    In this paper the authors describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes' method, a generalized least squares technique.

  15. Neutron cross-sections for 55Mn in the energy range from 0.2 to 22 MeV

    OpenAIRE

    RAHMAN, Abul Khaer Mohammad Rezaur

    2012-01-01

    Neutron total and differential elastic scattering cross-sections for 55Mn nucleus was calculated from different global spherical optical potential (SOP) sets for different neutron energies ranging from 0.2 MeV to 22 MeV using the well known computer program SCAT-2 on an IBM PC-AT. In addition, the angular distributions of elastically scattered neutrons at different neutron energies were calculated. The results were compared with those of the experimental data obtained from the EXFOR d...

  16. Using a Time Projection Chamber to Measure High Precision Neutron-Induced Fission Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Manning, Brett [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-06

    2014 LANSCE run cycle data will provide a preliminary 239Pu(n,f) cross section and will quantify uncertainties: PID and Target/beam non-uniformities. Continued running during the 2015 LANSCE run cycle: Thin targets to see both fission fragments and 239Pu(n,f) cross section and fully quantified uncertainties

  17. Measurement and analysis of the $^{243}$Am neutron capture cross section at the n_TOF facility at CERN

    CERN Document Server

    Mendoza, E; Guerrero, C; Berthoumieux, E; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Balibrea, J; Baumann, P; Becvar, F; Belloni, F; Calvino, F; Calviani, M; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Ferrant†, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonz alez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Ketlerov, V; Kerveno, M; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lossito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martınez, T; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O’Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vicente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2014-01-01

    Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the $^{243}$Am(n,$\\gamma$) cross section uncertainty. Method: The $^{243}$Am(n,$\\gamma$) cross section has been measured at the n_TOF facility at CERN with a BaF$_{2}$ Total Absorption Calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The $^{243}$Am(n,$\\gamma$) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature has been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the $^{243}$Am(n,$\\gamma$) cross section uncertainty and suggest that this cross section is underestimate...

  18. Measurement of Fission Cross-Sections for Neutrons of Energies in the Range 40-500 keV

    International Nuclear Information System (INIS)

    Measurements have been made of the fission cross-section of U233, U234 , U236, Np237, Pu239 and Pu241 at several neutron energies between 40 keV and 500 keV. Measurements in this energy range are of importance in reactor calculations especially in fast dilute systems where the neutron flux is high in the 10- 100-keV energy range. Recent measurements at this laboratory of the U235 fission cross-section gave absolute values slightly lower than previous data. The present series of measurements are made relative to the new values of the U235 fission cross-section using back-to-back ionization chambers. The fissile foils were assayed by α-assay, direct weighing and coulometry. Good agreement was obtained between these assays. The fission measurements have an estimated accuracy of between 1 % and.2% and,combined with the, error on the U235 fission cross-section,give a final error of about 3% in the fission cross-sections. The present results together with those of previous measurements are given, and the corrections for fission- fragment absorption, backgrounds and scattering are discussed. (author)

  19. COMBINE7.1 - A Portable ENDF/B-VII.0 Based Neutron Spectrum and Cross-Section Generation Program

    Energy Technology Data Exchange (ETDEWEB)

    Woo Y. Yoon; David W. Nigg

    2011-09-01

    COMBINE7.1 is a FORTRAN 90 computer code that generates multigroup neutron constants for use in the deterministic diffusion and transport theory neutronics analysis. The cross-section database used by COMBINE7.1 is derived from the Evaluated Nuclear Data Files (ENDF/B-VII.0). The neutron energy range covered is from 20 MeV to 1.0E-5 eV. The Los Alamos National Laboratory NJOY code is used as the processing code to generate a 167 fine-group cross-section library in MATXS format for Bondarenko self-shielding treatment. Resolved resonance parameters are extracted from ENDF/B-VII.0 File 2 for a separate library to be used in an alternate Nordheim self-shielding treatment in the resolved resonance energy range. The equations solved for energy dependent neutron spectrum in the 167 fine-group structure are the B3 or B1 zero-dimensional approximations to the transport equation. The fine group cross sections needed for the spectrum calculation are first prepared by Bondarenko self-shielding interpolation in terms of background cross section and temperature. The geometric lump effect, when present, is accounted for by augmenting the background cross section. Nordheim self-shielded fine group cross sections for a material having resolved resonance parameters overwrite correspondingly the existing self-shielded fine group cross sections when this option is used. COMBINE7.1 coalesces fine group cross sections into broad group macroscopic and microscopic constants. The coalescing is performed by utilizing fine-group fluxes and/or currents obtained by spectrum calculation as the weighting functions. The multigroup constants may be output in any of several standard formats including INL format, ANISN 14** free format, CCCC ISOTXS format, and AMPX working library format. ANISN-PC, a one-dimensional (1-D) discrete-ordinate transport code, is incorporated into COMBINE7.1. As an option, the 167 fine-group constants generated by zero-dimensional COMBINE portion in the program can be

  20. Radiochemical determination of the neutron capture cross sections of {sup 241}Am irradiated in the JMTR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, N.; Hatsukawa, Y.; Hata, K.; Kohno, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    The thermal neutron capture cross section {sigma}{sub 0} and Resonance integral I{sub 0} of {sup 241}Am leading to the production of {sup 242m}Am and {sup 242g}Am were measured by radiochemical method. The cross sections obtained in this study are {sigma}{sub 0}=60.9 {+-} 2.6 barn, I{sub 0}=213 {+-} 13 barn for {sup 241}Am(n,{gamma}){sup 242m}Am and {sigma}{sub 0}=736 {+-} 31 barn, I{sub 0}=1684 {+-} 92 barn for {sup 241}Am(n,{gamma}){sup 242g}Am. (author)

  1. A simultaneous evaluation of neutron induced reaction cross sections for 56Fe at En = 14.1 MeV

    International Nuclear Information System (INIS)

    A simultaneous evaluation of neutron induced reaction (i.e., (n,total), (n,n), (n,non), (n,n'), (n,2n), (n,nα), (n,np), (n,γ), (n,p), (n,d), (n,α), (n,n-em), (n,p-em), (n,d-em) and (n,α-em) reaction) cross sections on 56Fe at En = 14.1 MeV is carried out. The evaluated cross sections are compared with the corresponding measured values and the evaluations for CENDL-2, ENDF/B-6, JEF-2.2, JENDL-3 and BROND-2. (9 tabs., 1 fig)

  2. Transport analysis of measured neutron leakage spectra from spheres as tests of evaluated high energy cross sections

    Science.gov (United States)

    Bogart, D. D.; Shook, D. F.; Fieno, D.

    1973-01-01

    Integral tests of evaluated ENDF/B high-energy cross sections have been made by comparing measured and calculated neutron leakage flux spectra from spheres of various materials. An Am-Be (alpha,n) source was used to provide fast neutrons at the center of the test spheres of Be, CH2, Pb, Nb, Mo, Ta, and W. The absolute leakage flux spectra were measured in the energy range 0.5 to 12 MeV using a calibrated NE213 liquid scintillator neutron spectrometer. Absolute calculations of the spectra were made using version 3 ENDF/B cross sections and an S sub n discrete ordinates multigroup transport code. Generally excellent agreement was obtained for Be, CH2, Pb, and Mo, and good agreement was observed for Nb although discrepancies were observed for some energy ranges. Poor comparative results, obtained for Ta and W, are attributed to unsatisfactory nonelastic cross sections. The experimental sphere leakage flux spectra are tabulated and serve as possible benchmarks for these elements against which reevaluated cross sections may be tested.

  3. Development of a Multi-Group Neutron Cross Section Library Generation System for PWR

    International Nuclear Information System (INIS)

    This report describes a generation system of multi-group cross section library which is used in the KARMA lattice calculation code. In particular, the theoretical methodologies, program structures, and input preparations for the constituent programs of the system are described in detail. The library generation system consists of the following five programs : ANJOY, GREDIT, MERIT, SUBDATA, and LIBGEN. ANJOY generates automatically the NJOY input files and two batch files for automatic NJOY run for all the nuclides considered. The automatic NJOY run gives TAPE 23 (PENDF output file of BROADR module of NJOY) and TAPE24 (GENDF output file of GROUPR module of NJOY) files for each nuclide. GREDIT prepares a formatted multi-group cross section file in which the cross sections are tabulated versus temperature and background cross section after reading the TAPE24 file. MERIT generates the hydrogen equivalence factors and the resonance integral tables by solving the slowing down equation with ultra-fine group cross sections which are prepared with the TAPE 23 file. SUBDATA generates the subgroup data including subgroup levels and weights after reading the MERIT output file. Finally, LIBGEN generates the final multi-group library file by assembling the data prepared in the previous steps and by reading the other data such as fission product yield data and decay data.The multi-group cross section library includes general multi-group cross sections, resonance data, subgroup data, fission product yield data, kappa-values (energy release per fission), and all the data which are required in the depletion calculation. The addition or elimination of the cross sections for some nuclides can be easily done by changing the LIBGEN input file if the general multi-group cross section and the subgroup data files are prepared

  4. Neutron activation cross sections of medium-Z nuclei at 14.4 MeV

    International Nuclear Information System (INIS)

    Activation cross sections are measured for isotopes of nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, cadmium, tin, tellurium, antimony, iodine, barium, and cesium. From the measured (n,2n) cross sections an empirical formula as a function of only Z and A of the target nucleus is obtained. From the statistical model with the constant nuclear temperature approximation for level densities and other approximation, equations are derived to calculate (n,2n), (n,np), (n,pn), (n,p), (n,alpha), and (n,d) cross sections. 59 refs., 15 figs., 12 tabs

  5. Helium production cross section Measurement of Pb and Sn for 14.9 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Yoshiyuki; Fujimoto, Toshihiro; Ozaki, Shuji; Muramasu, Masatomo; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori; Ikeda, Yujiro

    1998-03-01

    Helium production cross sections of lead and tin for 14.9 MeV neutrons were measured by helium accumulation method. Lead and tin samples were irradiated with FNS, an intense d-T neutron source of JAERI. The amount of helium produced in the samples by the neutron irradiation was measured with the Helium Atoms Measurement System (HAMS) at Kyushu University. As the samples contained a small amount of helium because of their small helium production cross sections at 14.9 MeV, the samples were evaporated by radiation from a tungsten filament to decrease background gases at helium measurement. Uncertainties of the present results were less than {+-}4.4%. The results were compared with other experimental data in the literature and also compared with the evaluated values in JENDL-3.2. (author)

  6. Influence of the neutron numbers of projectile and target on the evaporation residue cross sections in hot fusion reactions

    Science.gov (United States)

    Zhu, Long; Su, Jun; Zhang, Feng-Shou

    2016-06-01

    Within the framework of a dinuclear system model, the influence of projectile and target neutron number on capture cross section, fusion probability, and survival probability for the reactions S,3634+238U and 48Ca+Pu 239 ,240 ,242 ,244 are investigated. The calculated excitation functions are in good agreement with the experimental data. To synthesize more unknown neutron-deficient isotopes of already-known superheavy elements, the possibility of using lighter calcium isotopes to induce hot fusion reactions is investigated and the maximal evaporation residual cross sections for Ca 44 ,46 ,48 -induced hot fusion reactions to produce unknown neutron-deficient superheavy nuclei with Z =112 -116 are predicted.

  7. Pulsed and monoenergetic beams for neutron cross-section measurements using activation and scattering techniques at Triangle Universities Nuclear Laboratory

    Science.gov (United States)

    Hutcheson, A.; Angell, C. T.; Becker, J. A.; Boswell, M.; Crowell, A. S.; Dashdorj, D.; Fallin, B.; Fotiades, N.; Howell, C. R.; Karwowski, H. J.; Kelley, J. H.; Kiser, M.; Macri, R. A.; Nelson, R. O.; Pedroni, R. S.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Weisel, G. J.; Wilhelmy, J. B.

    2007-08-01

    In support of the Stewardship Science Academic Alliances initiative, an experimental program has been developed at Triangle Universities Nuclear Laboratory (TUNL) to measure (n,xn) cross-sections with both in-beam and activation techniques with the goal of improving the partial cross-section database for the NNSA Stockpile Stewardship Program. First experimental efforts include excitation function measurements on 235,238U and 241Am using pulsed and monoenergetic neutron beams with En = 5-15 MeV. Neutron-induced partial cross-sections were measured by detecting prompt γ rays from the residual nuclei using various combinations of clover and planar HPGe detectors in the TUNL shielded neutron source area. Complimentary activation measurements using DC neutron beams have also been performed in open geometry in our second target area. The neutron-induced activities were measured in the TUNL low-background counting area. In this presentation, we include detailed information about the irradiation procedures and facilities and preliminary data on first measurements using this capability.

  8. Pulsed and monoenergetic beams for neutron cross-section measurements using activation and scattering techniques at Triangle Universities Nuclear Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hutcheson, A. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States)]. E-mail: hutch@tunl.duke.edu; Angell, C.T. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Becker, J.A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Boswell, M. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Crowell, A.S. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Dashdorj, D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Fallin, B. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Fotiades, N. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Howell, C.R.; Karwowski, H.J.; Kelley, J.H.; Kiser, M. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Macri, R.A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Nelson, R.O. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Pedroni, R.S. [NC A and T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); Tonchev, A.P.; Tornow, W. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Vieira, D.J. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Weisel, G.J. [Penn State Altoona, 3000 Ivyside Park, Altoona, PA 16601 (United States); Wilhelmy, J.B. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

    2007-08-15

    In support of the Stewardship Science Academic Alliances initiative, an experimental program has been developed at Triangle Universities Nuclear Laboratory (TUNL) to measure (n,xn) cross-sections with both in-beam and activation techniques with the goal of improving the partial cross-section database for the NNSA Stockpile Stewardship Program. First experimental efforts include excitation function measurements on {sup 235,238}U and {sup 241}Am using pulsed and monoenergetic neutron beams with E {sub n} = 5-15 MeV. Neutron-induced partial cross-sections were measured by detecting prompt {gamma} rays from the residual nuclei using various combinations of clover and planar HPGe detectors in the TUNL shielded neutron source area. Complimentary activation measurements using DC neutron beams have also been performed in open geometry in our second target area. The neutron-induced activities were measured in the TUNL low-background counting area. In this presentation, we include detailed information about the irradiation procedures and facilities and preliminary data on first measurements using this capability.

  9. Precision Measurement of 56Fe(n,n γ) Cross Sections Using 14.1 MeV Neutrons

    Science.gov (United States)

    Wang, Haoyu; Koltick, David

    2016-03-01

    Integral production cross sections for 846.8 keV and 1238.3 keV prompt gamma rays from 14.1 MeV neutrons interactions on 56Fe are reported. The experimental technique takes advantage of the 1.5 nanosecond coincidence timing resolution between the neutron production time and the gamma ray detection time to reject noise, together with the large 30% solid angle gamma ray coverage. The scattering angle coverage with respect to the neutron beam direction extends from 60 degrees to 120 degrees. The neutron flux is measured using the detected associated alpha-particle from the D-T fusion reaction produced using an associated particle neutron generator. Present cross section measurements using other techniques with limited timing resolution and solid angle coverage are in agreement at neutron energies lower than 6 MeV. At higher neutron energies reported results can disagree by more than 20%. The more accurate technique used in these measurements can distinguish between the differences in the present reported results at higher neutron energies. The author would like to thank TechSource, Inc. and Advanced Physics Technologies, LLC. for their support in this work.

  10. Fast-neutron capture cross sections of importance in technological applications

    International Nuclear Information System (INIS)

    The importance of the capture cross section of the major fertile nuclei, 238U and 232Th, leads to the consideration of these data. The 238U (n,γ) cross section is considered of priority as it is part of the 238U-239Pu cycle. Experimental techniques used in the measurements of these data are considered. Data measured more recently are compared with provisions made for the possible explanations of differing results. It is concluded that the 238U (n,γ) cross section is known with approx. 5% above 10 keV and fulfills the uncertainty limit for this cross section set to achieve design accuracy for k/sub eff/ and the breeding ratio above 500 keV. Below 500 keV, the present uncertainty falls short of the required 1.5 to 3.0% uncertainty. Specific recommendations are made to resolve existing discrepancies and data uncertainties. 84 references

  11. Fragmentation cross-sections and binding energies of neutron-rich nuclei

    CERN Document Server

    Tsang, M B; Friedman, W A; Mocko, M; Sun, Z Y; Aoi, N; Cook, J M; Delaunay, F; Famiano, M A; Hui, H; Imai, N; Iwasaki, H; Motobayashi, T; Niikura, M; Onishi, T; Rogers, A M; Sakuraï, H; Suzuki, H; Takeshita, E; Takeuchi, S; Wallace, M S

    2007-01-01

    An exponential dependence of the fragmentation cross-section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross-sections. From the systematics of 75,77,78,79Cu isotope cross-sections have been extracted. They are 636.94 +/- 0.40 MeV, 647.1 +/- 0.4 MeV, 651.6 +/- 0.4 MeV and 657.8 +/- 0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of 75Cu is reduced from 980 keV (listed value in the 2003 mass table of Audi and Wapstra) to 400 keV. The predicted cross-sections of two near drip-line nuclei, 39Na and 40Mg, from the fragmentation of 48Ca are discussed.

  12. Fragmentation cross sections and binding energies of neutron-rich nuclei

    Science.gov (United States)

    Tsang, M. B.; Lynch, W. G.; Friedman, W. A.; Mocko, M.; Sun, Z. Y.; Aoi, N.; Cook, J. M.; Delaunay, F.; Famiano, M. A.; Hui, H.; Imai, N.; Iwasaki, H.; Motobayashi, T.; Niikura, M.; Onishi, T.; Rogers, A. M.; Sakurai, H.; Suzuki, H.; Takeshita, E.; Takeuchi, S.; Wallace, M. S.

    2007-10-01

    An exponential dependence of the fragmentation cross section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross sections. From the systematics of Cu isotope cross sections, the binding energies of Cu76,77,78,79 have been extracted. They are 636.94±0.4,647.1±0.4,651.6±0.4, and 657.8±0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of Cu75 is reduced from 980 keV, as listed in the 2003 mass table of Audi, Wapstra, and Thibault to 400 keV. The predicted cross sections of two near drip-line nuclei, Na39 and Mg40 from the fragmentation of Ca48 are discussed.

  13. Analysis of Neutron Double-Differential Cross Section of n+14N at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    YANYu-Liang; DUANJun-Feng; SUNXiao-Jun; WANGJi-Min; ZHANGJing-Shang

    2005-01-01

    Abstract By using a new reaction model for light nuclei, the double-differential cross section of n+14N reactions at En=14.2 MeV has been analyzed. In the case of n+14N reactions, the reaction mechanism is very complex, there are over one hundred opened partial reaction channels even at incident energy En=14.2 MeV. In this paper the opened reaction channels are listed in detail. With LUNF code the model calculation is performed to analyze the doubledifferential cross sections of total outgoing neutron. The calculated results agree fairly with the experimental data. The results indicate that the pre-equilibrium mechanism dominates the whole reaction processes, and the recoil egect in light nuclear reactions is essentially important. 5He emission has been considered, but it is only a small contribution to thedouble-differential cross section at incident energy En=14.2 MeV.

  14. Analysis of Neutron Double-Differential Cross Section of n+14N at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    YAN Yu-Liang; DUAN Jun-Feng; SUN Xiao-Jun; WANG Ji-Min; ZHANG Jing-Shang

    2005-01-01

    By using a new reaction model for light nuclei, the double-differential cross section of n+14N reactions at En = 14.2 MeV has been analyzed. In the case of n+14N reactions, the reaction mechanism is very complex, there are over one hundred opened partial reaction channels even at incident energy En = 14.2 MeV. In this paper the opened reaction channels are listed in detail. With LUNF code the model calculation is performed to analyze the doubledifferential cross sections of total outgoing neutron. The calculated results agree fairly with the experimental data. The results indicate that the pre-equilibrium mechanism dominates the whole reaction processes, and the recoil effect in light nuclear reactions is essentially important. 5He emission has been considered, but it is only a small contribution to the double-differential cross section at incident energy En = 14.2 MeV.

  15. Semi-empirical systematics of (n, p) reaction cross sections for 14.5 MeV neutrons

    International Nuclear Information System (INIS)

    A new semi-empirical formula for the calculation of the (n, p) cross section at 14.5 MeV neutron energy is obtained. Derived from the evaporation statistical model, the new formula includes five parameters and shows for the first time a strong dependence of the (n, p) cross section on terms of the parameter (2Z-1)/A. Fitting this formula to the existing cross section data on 161 nuclei with 40≤A≤209, the adjustable parameters have been determined and the systematics of the (n, p) reaction have been studied. The predictions of this formula are compared with those of the existing formulae and with the experimental data. The formula with five parameters is found to give a better fit to the data than the previous comparable formulae

  16. Measurement of the effective thermal cross section of {sup 134}Cs by triple neutron capture reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Shoji; Harada, Hideo; Katoh, Toshio [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works; Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

    1998-03-01

    The effective thermal cross section ({sigma}{sub eff}) of the {sup 134}Cs(n,{gamma}){sup 135}Cs reaction was measured by the activation method and the {gamma}-ray spectroscopic method in order to obtain fundamental data for research on the transmutation of nuclear wastes. The effective thermal cross section of the reaction {sup 134}Cs(n,{gamma}){sup 135}Cs was found to be 140.6{+-}8.5 barns. (author)

  17. Deformation effect on reaction cross sections for neutron-rich Ne-isotopes induced reactions

    CERN Document Server

    Minomo, Kosho; Kimura, Masaaki; Ogata, Kazuyuki; Shimizu, Yoshifumi R; Yahiro, Masanobu

    2011-01-01

    Isotope-dependence of measured reaction cross sections in scattering of $^{28-32}$Ne isotopes from $^{12}$C target at 240 MeV/nucleon is analyzed by the double-folding model with the Melbourne $g$-matrix. The density of projectile is calculated by the mean-field model with the deformed Wood-Saxon potential. The deformation is evaluated by the antisymmetrized molecular dynamics. The deformation of projectile enhances calculated reaction cross sections to the measured values.

  18. Measurement of helium production cross sections of iron for d-T neutrons by helium accumulation method

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Yoshiyuki; Kanda, Yukinori; Nagae, Koji; Fujimoto, Toshihiro [Kyushu Univ., Fukuoka (Japan); Ikeda, Yujiro

    1997-03-01

    Helium production cross sections of Iron were measured by helium accumulation method for neutron energies from 13.5 to 14.9 MeV. Iron samples were irradiated with FNS, an intense d-T neutron source of JAERI. As the neutron energy varies according to the emission angle at the neutron source, the samples were set around the neutron source and were irradiated by neutrons of different energy depending on each sample position. The amount of helium produced in a sample was measured by Helium Atoms Measurement System at Kyushu University. The results of this work are in good agreement with other experimental data in the literature and also compared with the evaluated values in JENDL-3. (author)

  19. Velocity autocorrelation by quantum simulations for direct parameter-free computations of the neutron cross sections. II. Liquid deuterium

    Science.gov (United States)

    Guarini, E.; Neumann, M.; Bafile, U.; Celli, M.; Colognesi, D.; Bellissima, S.; Farhi, E.; Calzavara, Y.

    2016-06-01

    Very recently we showed that quantum centroid molecular dynamics (CMD) simulations of the velocity autocorrelation function provide, through the Gaussian approximation (GA), an appropriate representation of the single-molecule dynamic structure factor of liquid H2, as witnessed by a straightforward absolute-scale agreement between calculated and experimental values of the total neutron cross section (TCS) at thermal and epithermal incident energies. Also, a proper quantum evaluation of the self-dynamics was found to guarantee, via the simple Sköld model, a suitable account of the distinct (intermolecular) contributions that influence the neutron TCS of para-H2 for low-energy neutrons (below 10 meV). The very different role of coherent nuclear scattering in D2 makes the neutron response from this liquid much more extensively determined by the collective dynamics, even above the cold neutron range. Here we show that the Sköld approximation maintains its effectiveness in producing the correct cross section values also in the deuterium case. This confirms that the true key point for reliable computational estimates of the neutron TCS of the hydrogen liquids is, together with a good knowledge of the static structure factor, the modeling of the self part, which must take into due account quantum delocalization effects on the translational single-molecule dynamics. We demonstrate that both CMD and ring polymer molecular dynamics (RPMD) simulations provide similar results for the velocity autocorrelation function of liquid D2 and, consequently, for the neutron double differential cross section and its integrals. This second investigation completes and reinforces the validity of the proposed quantum method for the prediction of the scattering law of these cryogenic liquids, so important for cold neutron production and related condensed matter research.

  20. Measurement method of activation cross-sections of reactions producing short-lived nuclei with 14 MeV neutrons

    CERN Document Server

    Kawade, K; Kasugai, Y; Shibata, M; Iida, T; Takahashi, A; Fukahori, T

    2003-01-01

    We describe a method for obtaining reliable activation cross-sections in the neutron energy range between 13.4 and 14.9 MeV for the reactions producing short-lived nuclei with half-lives between 0.5 and 30 min. We noted neutron irradiation fields and measured induced activities, including (1) the contribution of scattered low-energy neutrons, (2) the fluctuation of the neutron fluence rate during the irradiation, (3) the true coincidence sum effect, (4) the random coincidence sum effect, (5) the deviation in the measuring position due to finite sample thickness, (6) the self-absorption of the gamma-ray in the sample material and (7) the interference reactions producing the same radionuclides or the ones emitting the gamma-ray with the same energy of interest. The cross-sections can be obtained within a total error of 3.6%, when good counting statistics are achieved, including an error of 3.0% for the standard cross-section of sup 2 sup 7 Al (n, alpha) sup 2 sup 4 Na. We propose here simple methods for measuri...

  1. Amino acids analysis using grouping and parceling of neutrons cross sections techniques; Analise de aminoacidos atraves das tecnicas do agrupamento e parcelamento de secoes de choque para neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante Luiz Voi [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Rocha, Helio Fenandes da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Puericultura e Pediatria Martagao Gesteira

    2002-07-01

    Amino acids used in parenteral administration in hospital patients with special importance in nutritional applications were analyzed to compare with the manufactory data. Individual amino acid samples of phenylalanine, cysteine, methionine, tyrosine and threonine were measured with the neutron crystal spectrometer installed at the J-9 irradiation channel of the 1 kW Argonaut Reactor of the Instituto de Engenharia Nuclear (IEN). Gold and D{sub 2}O high purity samples were used for the experimental system calibration. Neutron cross section values were calculated from chemical composition, conformation and molecular structure analysis of the materials. Literature data were manipulated by parceling and grouping neutron cross sections. (author)

  2. Neutron total cross-section model for liquids and its application to light water

    International Nuclear Information System (INIS)

    Highlights: → This model describes the total cross-section of molecular liquids aiming describe the subthermal energy range. → The model is amenable to perform calculations of interest in Nuclear Engineering. → The model describes the incoherent cross-section and is suited for hydrogenated liquids. → We apply the model to light water at room temperature. → The results compare favorably with experimental data - Abstract: In this article we present a model that describes the total cross-section of molecular liquids, aiming to provide a good description in the subthermal energy range with a minimum number of parameters, amenable to perform calculations of interest in Nuclear Engineering. We follow the spirit of Granada's Synthetic model that was successful in the thermal and epithermal ranges. The model describes the incoherent cross-section and is suited for hydrogenated liquids. We apply the model to light water at room temperature. The results compare favorably with experimental data. We compare with other models that describe the subthermal cross-sections. In the description we stress the need to have a good knowledge of the vibrational intermolecular energy spectrum, and the diffusion constant.

  3. Neutron cross sections of 187Os and their analysis with a possible correlation of the elastic and inelastic scattering channels

    International Nuclear Information System (INIS)

    The averaged total neutron cross sections in the energy range 1.9-144 keV and the elastic and inelastic scattering cross sections of neutrons of energy E = 24.4 keV have been measured for 187Os. All the experimental data on the neutron cross sections of 187Os in the energy range E ≤ 150 keV have been analyzed, taking into account a possible correlation of the elastic and inelastic scattering channels. The average resonance parameters of 187Os have been determined and are S0 = 2.44(21) x 10-4 eV-1/2, S1 = 0.368(41) x 10-4 eV-1/2, R∞0 = -0.243(25), and bar Γγ0 = 78.6(4.9) meV. The best approximation of the experimental data is obtained when the coefficient describing the correlation of the elastic and inelastic channel amplitude is ρ = 0.65. 19 refs., 8 figs., 3 tabs

  4. Eta photoproduction on the neutron at GRAAL: Measurement of the differential cross section

    CERN Document Server

    Rebreyend, D

    2005-01-01

    In this contribution, we will present our first preliminary measurement of the differential cross section for the reaction gamma+n->eta+n. Comparison of the reactions gamma+p->eta+p for free and bound proton (D2 target) will also be discussed.

  5. Fast-neutron capture cross sections of importance in technological applications. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Poenitz, W. P.

    1979-01-01

    The importance of the capture cross section of the major fertile nuclei, /sup 238/U and /sup 232/Th, leads to the consideration of these data. The /sup 238/U (n,..gamma..) cross section is considered of priority as it is part of the /sup 238/U-/sup 239/Pu cycle. Experimental techniques used in the measurements of these data are considered. Data measured more recently are compared with provisions made for the possible explanations of differing results. It is concluded that the /sup 238/U (n,..gamma..) cross section is known with approx. 5% above 10 keV and fulfills the uncertainty limit for this cross section set to achieve design accuracy for k/sub eff/ and the breeding ratio above 500 keV. Below 500 keV, the present uncertainty falls short of the required 1.5 to 3.0% uncertainty. Specific recommendations are made to resolve existing discrepancies and data uncertainties. 84 references.

  6. Measurement of 14 MeV neutron cross section of {sup 129}I with foil activation method

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Isao; Nakano, Daisuke; Takahashi, Akito [Osaka Univ., Suita (Japan). Faculty of Engineering

    1997-03-01

    The {sup 129}I, which is one of the most famous fission products (FPs), is of very important concern from the standpoint of waste transmutation due to its extremely long half life. The accurate reaction cross section data of {sup 129}I induced by 14 MeV neutrons are indispensable when evaluating the performance to transmute it in a fusion reactor. However, there was no available experimental data reported until now. We measured 14 MeV neutron induced reaction cross sections of {sup 129}I to give the reference cross section data for evaluation of transmutation performance and nuclear data, using OKTAVIAN facility of Osaka university, Japan. Since the available amount of {sup 129}I as a sample is quite small, probably less than 1 mg, the foil activation method was adopted in the measurement. The sample was a sealed source of {sup 129}I and the {gamma}-rays from the irradiated sample were measured with a Hp-Ge detector. Several {gamma}-rays peaks which could be expected to be caused by two nuclear reactions of {sup 129}I(n,2n) and {sup 129}I(n,{gamma}) were observed. We confirmed that these peaks corresponded to those of {sup 128}I and {sup 130}I through ascertaining each energy and half life. From the measurement, the cross section of {sup 129}I(n,2n) and the effective production cross section of {sup 130}I produced by the {sup 129}I(n,{gamma}){sup 130}I reaction including the contribution of {sup 129}I(n,{gamma}){sup 130m}I reaction, that were estimated to be 1.1{+-}0.1 b and 0.032{+-}0.003 b, respectively at 14.8 MeV, were obtained with an acceptable accuracy of about 10 %, though the errors caused by the uncertainty of {gamma} decay scheme data still existed. The measured cross sections were compared with the evaluated nuclear data of JENDL-3.2 and ENDF/B-VI. For the {sup 129}I(n,2n) reaction, the evaluations overestimate the cross section by 30-40 %, while for the {sup 129}I(n,{gamma}) reaction, the evaluations underestimate by at least one order of magnitude

  7. Advanced Monte Carlo procedure for the IFMIF d-Li neutron source term based on evaluated cross section data

    CERN Document Server

    Simakov, S P; Moellendorff, U V; Schmuck, I; Konobeev, A Y; Korovin, Y A; Pereslavtsev, P

    2002-01-01

    A newly developed computational procedure is presented for the generation of d-Li source neutrons in Monte Carlo transport calculations based on the use of evaluated double-differential d+ sup 6 sup , sup 7 Li cross section data. A new code M sup c DeLicious was developed as an extension to MCNP4C to enable neutronics design calculations for the d-Li based IFMIF neutron source making use of the evaluated deuteron data files. The M sup c DeLicious code was checked against available experimental data and calculation results of M sup c DeLi and MCNPX, both of which use built-in analytical models for the Li(d, xn) reaction. It is shown that M sup c DeLicious along with newly evaluated d+ sup 6 sup , sup 7 Li data is superior in predicting the characteristics of the d-Li neutron source. As this approach makes use of tabulated Li(d, xn) cross sections, the accuracy of the IFMIF d-Li neutron source term can be steadily improved with more advanced and validated data.

  8. The neutron capture cross sections of 186;187;188 Os and their application to Re/Os cosmochronometer

    CERN Document Server

    Fujii, Kaori; Mastinu, P; Milazzo, P M

    2009-01-01

    The aim of this thesis is a fine determination of 186;187;188Os neutron capture cross sections, in order to remove principal nuclear physics uncertainties on the age of the universe determined using the Re/Os cosmochronometer. A general introduction including stellar nucleosynthesis, nuclear cosmochronometry,available neutron facilities and neutron reaction features is given. Dedicated measurements of the 186;187;188Os capture cross sections have been performed at the CERN neutron time-of- ight facility, n TOF, in the neutron energy range from 1 eV up to 1 MeV. The details of the measurement and the data treatment are reported. Using obtained capture yields, resolved resonance region analysis is completed. Resonance parameters have been extracted from a full R-matrix fit. A statistical analysis has been performed and the related averaged resonance parameters are derived. This information is crucial for a complete understanding and modelling in terms of the Hauser-Feshbach statistical model of the capture and ...

  9. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    Science.gov (United States)

    Kahler, A. C.; MacFarlane, R. E.; Mosteller, R. D.; Kiedrowski, B. C.; Frankle, S. C.; Chadwick, M. B.; McKnight, R. D.; Lell, R. M.; Palmiotti, G.; Hiruta, H.; Herman, M.; Arcilla, R.; Mughabghab, S. F.; Sublet, J. C.; Trkov, A.; Trumbull, T. H.; Dunn, M.

    2011-12-01

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [M. B. Chadwick et al., "ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data," Nuclear Data Sheets, 112, 2887 (2011)]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected 235U and 239Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected

  10. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kahler, A.C.; Herman, M.; Kahler,A.C.; MacFarlane,R.E.; Mosteller,R.D.; Kiedrowski,B.C.; Frankle,S.C.; Chadwick,M.B.; McKnight,R.D.; Lell,R.M.; Palmiotti,G.; Hiruta,H.; Herman,M.; Arcilla,R.; Mughabghab,S.F.; Sublet,J.C.; Trkov,A.; Trumbull,T.H.; Dunn,M.

    2011-12-01

    The ENDF/B-VII.1 library is the latest revision to the United States Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [M. B. Chadwick et al., 'ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data,' Nuclear Data Sheets, 112, 2887 (2011)]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected {sup 235}U and {sup 239}Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also

  11. A 4p BaF2 detector for (n,g) cross section measurements at a spallation neutron source

    CERN Document Server

    Heil, M; Fowler, M M; Haight, R C; Käppeler, F; Rundberg, R S; Seabury, E H; Ullmann, J L; Wilhelmy, J B; Wisshak, K

    2013-01-01

    The quest for improved neutron capture cross sections for advanced reactor concepts, transmutation of radioactive wastes as well as for astrophysical scenarios of neutron capture nucleosynthesis has motivated new experimental efforts based on modern techniques. Recent measurements in the keV region have shown that a 4p BaF2 detector represents an accurate and versatile instrument for such studies. The present work deals with the potential of such a 4p BaF2 detector in combination with spallation neutron sources, which offer large neutron fluxes over a wide energy range. Detailed Monte Carlo simulations with the GEANT package have been performed to investigate the critical backgrounds at a spallation facility, to optimize the detector design, and to discuss alternative solutions.

  12. Measurement of the neutron-induced fission cross sections of /sup 242/Cm and /sup 238/Pu

    International Nuclear Information System (INIS)

    The neutron-induced fission cross sections of /sup 242/Cm and /sup 238/Pu have been measured from 0.1 eV to 100 keV using the Rensselaer Intense Neutron Spectrometer. Fission areas and widths were determined for several resolved low-energy resonances of /sup 242/Cm and /sup 238/Pu. The fission resonance integrals for /sup 242/Cm and /sup 238/Pu were found to be 12.9 +- 0.7 and 15.9 +- 0.6 b, respectively. The gross structure observed in the unresolved energy region of the /sup 242/Cm and /sup 238/Pu fission cross sections is suggestive of intermediate structure, and is consistent with the second well lying 2 to 3 MeV above the first well. The ENDF/B-V library fission cross section of /sup 238/Pu is, in general, not in good agreement with this measurement and a new evaluation is recommended. This is the first reported fission measurement of /sup 242/Cm in the 0.1-eV through 100-keV energy range

  13. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    Science.gov (United States)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Naik, Haladhara; Shahid, Muhammad; Lee, Manwoo

    2015-08-01

    The cross-sections for 209Bi(n, 4n)206Bi, 209Bi(n, 5n)205Bi, natPb(n, xn)204mPb, natPb(n, xn)203Pb, natPb(n, xn)202mPb,natPb(n, xn)201Pb, natPb(n, xn)200Pb, natPb(n, αxn)203Hg and natPb(n, p xn)202Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the 9Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code.

  14. Influence of target-scattered neutrons on cross-section measurements

    International Nuclear Information System (INIS)

    Monoenergetic neutrons produced with accelerators are usually accompanied by degraded and secondary neutrons which arise from reactions of source neutrons in the material of the target construction. A Monte Carlo code was written which takes into account the kinematics and the angular source strength of the neutron producing reaction and the interactions of the neutrons with the material in the immediate vicinity of their production. The calculation of the spectral distribution of the neutron fluence is compared with the result of a time-of-flight measurement. (author)

  15. Evaluation of the neutron cross sections of 235U in the thermal energy region. Final report

    International Nuclear Information System (INIS)

    The objective of this work has been to improve the knowledge of the thermal cross sections of the fissile nuclei as a step toward providing a standard data base for the nuclear industry. The methodology uses a form of the Adler-Adler multilevel-fission theory and Breit-Wigner multilevel-scattering theory. It incorporates these theories in a general nonlinear least-squares (LSQ) fitting program SIGLEARNThe analysis methodology in this work was applied to the thermal data on 235U. A reference data file has been developed which includes most of the known data of interest. The first important result of this work is the assessment of the shape uncertainties of the partial cross sections. The results of our studies lead to the following values and error estimates for 235U g factors in a thermal (20.440C) energy spectrum: g/sub f/ = 0.97751 (+-0.11%); g/sub γ/ = 0.98230 (+-0.14%). A second important result of this study is the development of a recommended set of 2200 m/s (0.0253 eV) values of the parameters and the probable range of further adjustment which might be made. The analysis also provides the result of a common interpretation of energy-dependent absolute cross-section data of different measurements to yield a consistent set of experimental 0.0253 eV values with rigorous error estimates. It also provides normalization factors for relative fission and capture cross sections on a common basis with rigorous error estimates. The results of these analyses provide a basis for deciding what new measurements would be most beneficial. The most important of these would be improved direct capture data in the thermal region

  16. Measurement of thermal neutron cross section and resonance integral for (n,{gamma}) reaction in {sup 152}Sm

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Mustafa [Gazi University, Gazi Education Faculty, 06500 Teknikokullar - Ankara (Turkey)]. E-mail: mkaradag@gazi.edu.tr; Yuecel, Haluk [Saraykoey Nuclear Research and Training Center (SNRTC), 06983 Saray - Ankara (Turkey); Gueray Budak, M. [Gazi University, Gazi Education Faculty, 06500 Teknikokullar - Ankara (Turkey)

    2007-03-15

    This study implies that {sup 55}Mn(n,{gamma}){sup 55}Mn monitor reaction may be a convenient alternative comparator for the activation method and thus, it was used for the determination of thermal neutron cross section (TNX) and the resonance integral (RI) of the reaction {sup 152}Sm(n,{gamma}){sup 153}Sm. The samples of MnO{sub 2} and Sm{sub 2}O{sub 3} diluted with Al{sub 2}O{sub 3} powder were irradiated within and without a cylindrical 1 mm-Cd shield case in an isotropic neutron field obtained from the {sup 241}Am-Be neutron sources. The {gamma}-ray spectra from the irradiated samples were measured by high resolution {gamma}-ray spectrometry with a calibrated n-type Ge detector. The correction factors for {gamma}-ray attenuation, thermal neutron and resonance neutron self-shielding effects and epithermal neutron spectrum shape factor ({alpha}) were taken into account in the determinations. The thermal neutron cross section for {sup 152}Sm(n,{gamma}){sup 153}Sm reaction has been determined to be 204.8 {+-} 7.9 b at 0.025 eV. This result has been obtained relative to the reference thermal neutron cross section value of 13.3 {+-} 0.1 b for the {sup 55}Mn(n,{gamma}){sup 56}Mn reaction. For the TNX, most of the experimental data and evaluated one in JEFF-3.1, ENDF/B-VI, JENDL 3.3 and BROND 2.0, in general, agree well with the present result. The RI value for {sup 152}Sm(n,{gamma}){sup 153}Sm reaction has also been determined to be 3038 {+-} 214 b, relative to the reference value of 14.0 {+-} 0.3 b for the {sup 55}Mn(n,{gamma}){sup 56}Mn monitor reaction, using a 1/E {sup 1+{alpha}} epithermal neutron spectrum and assuming Cd cut-off energy of 0.55 eV. In surveying literature, the existing experimental and evaluated data for the RI values are distributed from 1715 to 3462 b. However, when the Cd cut-off energy is defined as 0.55 eV, the present RI value agrees with some previously reported RI values, 3020 {+-} 163 b by Simonits et al., 3141 {+-} 157 by Van Der Linden

  17. Theoretical Analysis of Neutron Double-Differential Cross Section of n+10B at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Shang

    2003-01-01

    By using a new reaction model for light nuclei, the double-differential cross sections of n+ 10B reactions atEn = 14.2 MeV have been analyzed. In the case of n+10B reactions there are over one hundred opened partial reactionchannels. Besides the sequential particle emissions, there is also the three-body breakup process, in which the kinematicsis classified into four types. In this paper the opened reaction channels are listed in detail with the LUNF code, withwhich the model calculation is performed to analyze the total outgoing neutron double-differential cross sections. All ofthe fittings agree fairly well with the measurements. The calculation results indicate that the pre-equilibrium mechanismdominates the whole reaction processes, and the recoil effect in light nuclear reaction is essentially important.

  18. Production and Validation of Isotope Production Cross Section Libraries for Neutrons and Protons to 1.7 GeV

    CERN Document Server

    Mashnik, S G; Van Riper, K A; Wilson, W B

    1998-01-01

    For validation and development of codes and for modeling isotope production in high power accelerators and APT Materials studies, we have produced experimental, calculated, and evaluated activation libraries for interaction of nucleons with nuclides covering about a third of all natural elements. For targets considered here, our compilation of experimental data is the most complete we are aware of, since it contains all data available on the Web, in journal papers, laboratory reports, theses, and books, as well as all data included in the large compilation by Sobolevsky with co-authors (NUCLEX) published recently by Springer-Verlag in 4 volumes. Our evaluated library was produced using all available experimental cross sections together with calculations by the CEM95, LAHET, and HMS-ALICE codes and with the European Activation File EAF-97 and LANL Update II of the ECNAF Neutron Activation Cross-Section Library.

  19. A simultaneous evaluation of neutron induced reaction cross sections for 56Fe at En = 14.1 MeV

    International Nuclear Information System (INIS)

    A simultaneous evaluation of neutron induced reaction (i.e., (n,total), (n,n), (n,non), (n,n'), (n,2n), (n,nα), (n,np), (n,γ), (n,p), (n,d), (n,α), (n,n-em), (n,p-em), (n,d-em) and (n,α-em) reaction) cross sections on 56Fe at En = 14.1 MeV is carried out. The evaluated cross sections are compared with the corresponding measured values and the evaluations for CENDL-2, ENDF/B-6, JEF-2.2, JENDL-3 and BROND-2. (author). 27 refs, 1 fig., 8 tabs

  20. Theoretical Analysis of Neutron Double-Differential Cross Section of n + 19F at 14.2 MeV

    Institute of Scientific and Technical Information of China (English)

    DUAN Jun-Feng; YAN Yu-Liang; SUN Xiao-Jun; ZHANG Yue; ZHANG Jing-Shang

    2007-01-01

    A new light nuclear reaction model has been developed and the double-differential measurements of 1p shell nuclei have been analyzed successfully. Now, the application of this model is expanded to 19F of the 2s-1d shell nucleus. The double-differential cross section of total outgoing neutron for n + 19F reactions at En = 14.2 MeV has been calculated and analyzed, which agrees fairly well with the experimental measurements. In this paper, the contributions from different reaction channels to the double-differential cross sections have been analyzed in detail. The calculations indicate that this light nuclear reaction model is also able to be used for the 2s-1d shell nucleus so long as the related level scheme could be provided sufficiently.

  1. Fission cross-sections, prompt fission neutron and γ-ray emission in request for nuclear applications

    Directory of Open Access Journals (Sweden)

    Hambsch F.-J.

    2016-01-01

    Full Text Available In recent years JRC-IRMM has been investigating fission cross-sections of 240,242Pu in the fast-neutron energy range relevant for innovative reactor systems and requested in the High Priority Request List (HPRL of the OECD/Nuclear Energy Agency (NEA. In addition to that, prompt neutron multiplicities are being investigated for the major isotopes 235U, 239Pu in the neutron-resonance region using a newly developed scintillation detector array (SCINTIA and an innovative modification of the Frisch-grid ionisation chamber for fission-fragment detection. These data are highly relevant for improved neutron data evaluation and requested by the OECD/Working Party on Evaluation Cooperation (WPEC. Thirdly, also prompt fission γ-ray emission is investigated using highly efficient lanthanide-halide detectors with superior timing resolution. Again, those data are requested in the HPRL for major actinides to solve open questions on an under-prediction of decay heat in nuclear reactors. The information on prompt fission neutron and γ-ray emission is crucial for benchmarking nuclear models to study the de-excitation process of neutron-rich fission fragments. Information on γ-ray emission probabilities is also useful in decommissioning exercises on damaged nuclear power plants like Fukushima Daiichi to which JRC-IRMM is contributing. The results on the 240,242Pu fission cross section, 235U prompt neutron multiplicity in the resonance region and correlations with fission fragments and prompt γ-ray emission for several isotopes will be presented and put into perspective.

  2. Fission cross-sections, prompt fission neutron and γ-ray emission in request for nuclear applications

    Science.gov (United States)

    Hambsch, F.-J.; Salvador-Castiñeira, P.; Oberstedt, S.; Göök, A.; Billnert, R.

    2016-06-01

    In recent years JRC-IRMM has been investigating fission cross-sections of 240,242Pu in the fast-neutron energy range relevant for innovative reactor systems and requested in the High Priority Request List (HPRL) of the OECD/Nuclear Energy Agency (NEA). In addition to that, prompt neutron multiplicities are being investigated for the major isotopes 235U, 239Pu in the neutron-resonance region using a newly developed scintillation detector array (SCINTIA) and an innovative modification of the Frisch-grid ionisation chamber for fission-fragment detection. These data are highly relevant for improved neutron data evaluation and requested by the OECD/Working Party on Evaluation Cooperation (WPEC). Thirdly, also prompt fission γ-ray emission is investigated using highly efficient lanthanide-halide detectors with superior timing resolution. Again, those data are requested in the HPRL for major actinides to solve open questions on an under-prediction of decay heat in nuclear reactors. The information on prompt fission neutron and γ-ray emission is crucial for benchmarking nuclear models to study the de-excitation process of neutron-rich fission fragments. Information on γ-ray emission probabilities is also useful in decommissioning exercises on damaged nuclear power plants like Fukushima Daiichi to which JRC-IRMM is contributing. The results on the 240,242Pu fission cross section, 235U prompt neutron multiplicity in the resonance region and correlations with fission fragments and prompt γ-ray emission for several isotopes will be presented and put into perspective.

  3. The cross-section data from neutron activation experiments on niobium in the NPI p-7Li quasi-monoenergetic neutron field

    Science.gov (United States)

    Honusek, M.; Bém, P.; Fischer, U.; Götz, M.; Novák, J.; Simakov, S. P.; Šimečková, E.

    2010-10-01

    The reaction of protons on 7Li target produces the high-energy quasi- monoenergetic neutron spectrum with the tail to lower energies. Proton energies of 19.8, 25.1, 27.6, 30.1, 32.6, 35.0 and 37.4 MeV were used to obtain quasi-monoenergetic neutrons with energies of 18, 21.6, 24.8, 27.6, 30.3, 32.9 and 35.6 MeV, respectively. Nb cross-section data for neutron energies higher than 22.5 MeV do not exist in the literature. Nb is the important material for fusion applications (IFMIF) as well. The variable-energy proton beam of NPI cyclotron is utilized for the production of neutron field using thin lithium target. The carbon backing serves as the beam stopper. The system permits to produce neutron flux density about 109 n/cm2/s in peak at 30 MeV neutron energy. The niobium foils of 15 mm in diameter and approx. 0.75 g weight were activated. The nuclear spectroscopy methods with HPGe detector technique were used to obtain the activities of produced isotopes. The large set of neutron energies used in the experiment allows us to make the complex study of the cross-section values. The reactions (n,2n), (n,3n), (n,4n), (n,He3), (n,α) and (n,2nα) are studied. The cross-sections data of the (n,4n) and (n,2nα) are obtained for the first time. The cross-sections of (n,2n) and (n,α) reactions for higher neutron energies are strongly influenced by low energy tail of neutron spectra. This effect is discussed. The results are compared with the EAF-2007 library.

  4. The cross-section data from neutron activation experiments on niobium in the NPI p-7Li quasi-monoenergetic neutron field

    Directory of Open Access Journals (Sweden)

    Simakov S.P.

    2010-10-01

    Full Text Available The reaction of protons on 7Li target produces the high-energy quasi- monoenergetic neutron spectrum with the tail to lower energies. Proton energies of 19.8, 25.1, 27.6, 30.1, 32.6, 35.0 and 37.4 MeV were used to obtain quasi-monoenergetic neutrons with energies of 18, 21.6, 24.8, 27.6, 30.3, 32.9 and 35.6 MeV, respectively. Nb cross-section data for neutron energies higher than 22.5 MeV do not exist in the literature. Nb is the important material for fusion applications (IFMIF as well. The variable-energy proton beam of NPI cyclotron is utilized for the production of neutron field using thin lithium target. The carbon backing serves as the beam stopper. The system permits to produce neutron flux density about 109  n/cm2/s in peak at 30 MeV neutron energy. The niobium foils of 15 mm in diameter and approx. 0.75 g weight were activated. The nuclear spectroscopy methods with HPGe detector technique were used to obtain the activities of produced isotopes. The large set of neutron energies used in the experiment allows us to make the complex study of the cross-section values. The reactions (n,2n, (n,3n, (n,4n, (n,He3, (n,α and (n,2nα are studied. The cross-sections data of the (n,4n and (n,2nα are obtained for the first time. The cross-sections of (n,2n and (n,α reactions for higher neutron energies are strongly influenced by low energy tail of neutron spectra. This effect is discussed. The results are compared with the EAF-2007 library.

  5. Measurement of double-differential neutron emission cross sections of 238U, 232Th and 12C for 18 MeV neutrons

    International Nuclear Information System (INIS)

    Double-differential neutron emission cross sections of 238U, 232Th and 12C have been measured for 18-MeV incident neutrons using the neutron time-of-flight technique and Tohoku University 4.5MV Dynamitron accelerator as a pulsed neutron generator. In the experiment, energy resolution of the spectrometer was improved by employing a newly developed post-acceleration beam-chopper and by adjustment of timing property of the neutron detector. Measurements were made at laboratory angles between 30- and 145- deg., and data were obtained for secondary neutrons between 0.8 and 18 MeV. In the data processing, a care was taken for the data correction for the effects of parasitic neutrons associated with primary neutrons; the correction proved to be of special importance in the present measurement. We compared the data obtained in the present experiment with the evaluated data, JENDL-3 and ENDF/B-IV (B-V for 12C), and discussed the origin of the discrepancies. The anisotropy observed for secondary neutrons from 238U and 232Th was found to be reproduced by Kalbach-Mann systematics on the assumption of isotropy of fission neutrons. The experimental results for 12C showed marked discrepancies concerning the scattering cross sections and neutron spectrum in the continuum region. (author)

  6. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    International Nuclear Information System (INIS)

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 418 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [1]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unmoderated and uranium reflected 235U and 239Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected actinide reaction rates such as 236U capture. Other deficiencies, such as the overprediction of Pu solution system critical eigenvalues and a decreasing trend in calculated eigenvalue for

  7. ENDF/B-VII.1 Neutron Cross Section Data Testing with Critical Assembly Benchmarks and Reactor Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kahler, A. [Los Alamos National Laboratory (LANL); Macfarlane, R E [Los Alamos National Laboratory (LANL); Mosteller, R D [Los Alamos National Laboratory (LANL); Kiedrowski, B C [Los Alamos National Laboratory (LANL); Frankle, S C [Los Alamos National Laboratory (LANL); Chadwick, M. B. [Los Alamos National Laboratory (LANL); Mcknight, R D [Argonne National Laboratory (ANL); Lell, R M [Argonne National Laboratory (ANL); Palmiotti, G [Idaho National Laboratory (INL); Hiruta, h [Idaho National Laboratory (INL); Herman, Micheal W [Brookhaven National Laboratory (BNL); Arcilla, r [Brookhaven National Laboratory (BNL); Mughabghab, S F [Brookhaven National Laboratory (BNL); Sublet, J C [Culham Science Center, Abington, UK; Trkov, A. [Jozef Stefan Institute, Slovenia; Trumbull, T H [Knolls Atomic Power Laboratory; Dunn, Michael E [ORNL

    2011-01-01

    The ENDF/B-VII.1 library is the latest revision to the United States' Evaluated Nuclear Data File (ENDF). The ENDF library is currently in its seventh generation, with ENDF/B-VII.0 being released in 2006. This revision expands upon that library, including the addition of new evaluated files (was 393 neutron files previously, now 423 including replacement of elemental vanadium and zinc evaluations with isotopic evaluations) and extension or updating of many existing neutron data files. Complete details are provided in the companion paper [1]. This paper focuses on how accurately application libraries may be expected to perform in criticality calculations with these data. Continuous energy cross section libraries, suitable for use with the MCNP Monte Carlo transport code, have been generated and applied to a suite of nearly one thousand critical benchmark assemblies defined in the International Criticality Safety Benchmark Evaluation Project's International Handbook of Evaluated Criticality Safety Benchmark Experiments. This suite covers uranium and plutonium fuel systems in a variety of forms such as metallic, oxide or solution, and under a variety of spectral conditions, including unmoderated (i.e., bare), metal reflected and water or other light element reflected. Assembly eigenvalues that were accurately predicted with ENDF/B-VII.0 cross sections such as unrnoderated and uranium reflected (235)U and (239)Pu assemblies, HEU solution systems and LEU oxide lattice systems that mimic commercial PWR configurations continue to be accurately calculated with ENDF/B-VII.1 cross sections, and deficiencies in predicted eigenvalues for assemblies containing selected materials, including titanium, manganese, cadmium and tungsten are greatly reduced. Improvements are also confirmed for selected actinide reaction rates such as (236)U; (238,242)Pu and (241,243)Am capture in fast systems. Other deficiencies, such as the overprediction of Pu solution system critical

  8. Modeled Neutron and Charged-Particle Induced Nuclear Reaction Cross Sections for Radiochemistry in the Region of Yttrium, Zirconium, Niobium, and Molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Kelley, K; Dietrich, F S; Bauer, R; Mustafa, M G

    2006-06-13

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron, proton, and deuteron induced nuclear reaction cross sections for targets ranging from strontium (Z = 38) to rhodium (Z = 45).

  9. A new modelling of the multigroup scattering cross section in deterministic codes for neutron transport

    International Nuclear Information System (INIS)

    In reactor physics, calculation schemes with deterministic codes are validated with respect to a reference Monte Carlo code. The remaining biases are attributed to the approximations and models induced by the multigroup theory (self-shielding models and expansion of the scattering law using Legendre polynomials) to represent physical phenomena (resonant absorption and scattering anisotropy respectively). This work focuses on the relevance of a polynomial expansion to model the scattering law. Since the outset of reactor physics, the latter has been expanded on a truncated Legendre polynomial basis. However, the transfer cross sections are highly anisotropic, with non-zero values for a very small range of the cosine of the scattering angle. Besides, the finer the energy mesh and the lighter the scattering nucleus, the more exacerbated is the peaked shape of this cross section. As such, the Legendre expansion is less suited to represent the scattering law. Furthermore, this model induces negative values which are non-physical. In this work, various scattering laws are briefly described and the limitations of the existing model are pointed out. Hence, piecewise-constant functions have been used to represent the multigroup scattering cross section. This representation requires a different model for the diffusion source. The discrete ordinates method which is widely employed to solve the transport equation has been adapted. Thus, the finite volume method for angular discretization has been developed and implemented in Paris environment which hosts the Sn solver, Snatch. The angular finite volume method has been compared to the collocation method with Legendre moments to ensure its proper performance. Moreover, unlike the latter, this method is adapted for both the Legendre moments and the piecewise-constant functions representations of the scattering cross section. This hybrid-source method has been validated for different cases: fuel cell in infinite lattice

  10. Triaxiality as essential feature for electromagnetic strength, level density and neutron capture cross sections in heavy nuclei

    International Nuclear Information System (INIS)

    Reliable predictions for compound nuclear processes leading to nuclides outside the valley of stability are of importance for nuclear astrophysics as well as for the transmutation of nuclear waste. Assuming triaxiality in nearly all nuclei with A>70 a combined parameterization is presented for level density and photon strength. For the strength functions a fit to IVGDR shapes by the sum of three Lorentzians adding up to the TRK sum rule is used. Only two global fit-parameters are needed and a third one suffices to also describe level densities sufficiently well, if the significant collective enhancement due to the loss of axial symmetry is accounted for. Predicted level distances for the small spins reached by capture at the neutron threshold agree well to observations for more than 100 spin-0 target nuclei. Simultaneously derived neutron capture cross sections in the range of unresolved resonances are in accord to experimental findings as well as to Maxwellian averages (kT=30 keV) of neutron capture cross sections compiled recently for simulations of nuclear reactions in AGB-stars.

  11. Measurements of double-differential neutron emission cross sections of Nb and Bi for 11.5 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ibaraki, Masanobu; Matsuyama, Shigeo; Soda, Daisuke; Baba, Mamoru; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering

    1997-03-01

    Double-differential neutron emission cross sections (DDXs) of Nb and Bi have been measured for 11.5MeV neutrons using the {sup 15N}(d,n){sup 16}O quasi-monoenergetic neutron source at Tohoku University 4.5MV Dynamitron facility. For En`>6MeV, DDXs were measured by the conventional TOF method (single-TOF:S-TOF). For En`<6MeV, where the S-TOF spectra were distorted by the background neutrons, we adopted a double-TOF method (D-TOF). By applying D-TOF method, we obtained DDXs down to 1MeV. (author)

  12. Measurements of double-differential neutron emission cross sections of {sup 6}Li and {sup 7}Li for 18 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo; Sanami, Toshiya; Win, T.; Miura, Takako; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering

    1997-03-01

    Double-differential neutron emission cross sections of {sup 6}Li and {sup 7}Li were measured for 18 MeV neutrons at Tohoku University 4.5 MV Dynamitron facility. Neutron emission spectra were obtained down to 1 MeV at 13 angles with energy resolution good enough to separate discrete levels. A care was taken to eliminate the sample-dependent background due to parasitic neutrons. Experimental results were in fair agreement with the JENDL-3.2 data and a simple model considering a three-body breakup process and discrete level excitations. (author)

  13. Investigation of the sup 9 sup 3 Nb neutron cross-sections in resonance energy range

    CERN Document Server

    Grigoriev, Y V; Faikov-Stanchik, H; Ilchev, G; Kim, G N; Kitaev, V Ya; Mezentseva, Z V; Panteleev, T; Sinitsa, V V; Zhuravlev, B V

    2001-01-01

    The results of gamma-ray multiplicity spectra and transmission measurements for sup 9 sup 3 Nb in energy range 21.5 eV-100 keV are presented. Gamma spectra from 1 to 7 multiplicity were measured on the 501 m and 121 m flight paths of the IBR-30 using a 16-section scintillation detector with a NaI(Tl) crystals of a total volume of 36 l and a 16-section liquid scintillation detector of a total volume of 80 l for metallic samples of 50, 80 mm in diameter and 1, 1.5 mm thickness with 100% sup 9 sup 3 Nb. Besides, the total and scattering cross-section of sup 9 sup 3 Nb were measured by means batteries of B-10 and He-3 counters on the 124 m, 504 m and 1006 m flight paths of the IBR-30. Spectra of multiplicity distribution were obtained for resolved resonances in the energy region E=30-6000 eV and for energy groups in the energy region E=21.5 eV- 100 keV. They were used for determination of the average multiplicity, resonance parameters and capture cross-section in energy groups and for low-laying resonances of sup...

  14. Impact of the γ _{ν }NN* Electrocoupling Parameters at High Photon Virtualities and Preliminary Cross Sections off the Neutron

    Science.gov (United States)

    Gothe, Ralf W.; Tian, Ye

    2016-10-01

    Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from already explored—where meson-cloud degrees of freedom contribute substantially to the baryon structure—to still unexplored distance scales—where quark degrees of freedom dominate and the transition from dressed to current quarks occurs—we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that can then be compared to state-of-the-art models and QCD-based calculations. The vast majority of the available exclusive electroproduction cross sections are off the proton. Hence flavor-dependent analyses of excited light-quark baryons are lacking experimental data off the neutron. The goal is to close this gap by providing exclusive {γ }_{ν }(n) → p+ {π }- reaction cross section off deuterium and to establish a kinematical final-state-interaction (FSI) correction factor (R) map that can be determined from the data set itself. The "e1e" Jefferson Lab CLAS data set, that is analyzed, includes both a hydrogen and deuterium target run period, which allows a combined

  15. R-Matrix Evaluation of Cl Neutron Cross Sections up to 1.2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.

    2003-03-27

    We have performed an evaluation of {sup 35}Cl, {sup 37}Cl, and {sup nat}Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were carried out with the computer code SAMMY, which utilizes Bayes' method, a generalized least squares technique. A recent modification of SAMMY enabled us to calculate charged particle penetrabilities for the proton exit channel. Our resonance parameter representation describes the data much better than does ENDF/B-VI, and it should lead to improved criticality safety calculations for systems where Cl is present.

  16. Impact of the γ _{ν } NN* Electrocoupling Parameters at High Photon Virtualities and Preliminary Cross Sections off the Neutron

    Science.gov (United States)

    Gothe, Ralf W.; Tian, Ye

    2016-06-01

    Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from already explored—where meson-cloud degrees of freedom contribute substantially to the baryon structure—to still unexplored distance scales—where quark degrees of freedom dominate and the transition from dressed to current quarks occurs—we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that can then be compared to state-of-the-art models and QCD-based calculations. The vast majority of the available exclusive electroproduction cross sections are off the proton. Hence flavor-dependent analyses of excited light-quark baryons are lacking experimental data off the neutron. The goal is to close this gap by providing exclusive {γ }_{ν }(n) → p+ {π }- reaction cross section off deuterium and to establish a kinematical final-state-interaction (FSI) correction factor (R) map that can be determined from the data set itself. The "e1e" Jefferson Lab CLAS data set, that is analyzed, includes both a hydrogen and deuterium target run period, which allows a combined

  17. Calculation of Cross Section of Radiative Halo-Neutron Capture by 12C at Stellar Energy with the Asymptotic Normalization Coefficient Method

    Institute of Scientific and Technical Information of China (English)

    WU Kai-Su; CHEN Yong-Shou; LIU Zu-Hua; LIN Cheng-Jian; ZHANG Huan-Qiao

    2003-01-01

    The cross section of the direct neutron capture reaction 12C(n,7)13C(l/2+) is calculated with the asymptotic normalization coefficient method. The result is in good agreement with a recent experiment at low energy. An enormous enhancement of cross section is found for this direct neutron capture in which a p-wave neutron is captured into an 2?i/2 orbit with neutron halo. The possible effect of the neutron halo structure presented in this reaction on the s-process in astrophysics is discussed in general.

  18. Measurement of cross sections producing short-lived nuclei by 14 MeV neutron. Br, Te, Dy, Ho, Yb

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Matsumoto, T.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.

    1997-03-01

    Nine neutron activation cross sections producing the nuclei with half-lives between 2 min and 57 min have been measured at energy range between 13.4 and 14.9 MeV for Br, Te, Dy, Ho, Yb. The cross sections of {sup 81}Br(n,p){sup 81m}Se, {sup 128}Te(n,p){sup 128m}Sb, {sup 128}Te(n,{alpha}){sup 125m}Sn, {sup 164}Dy(n,p){sup 164}Tb, {sup 165}Ho(n,{alpha}){sup 162}Tb, {sup 176}Yb(n,p){sup 176}Tm were newly obtained at the six energy points between 13.4-14.9 MeV, although the previous results have been obtained at one energy point. {sup 79}Br(n,2n){sup 78}Br, {sup 164}Dy(n,p){sup 164}Tb are compared with evaluated data of JENDL-3.2. The evaluations for these reactions agree reasonably well with experimental results. The cross sections of (n,p) reaction are compared with systematics by Kasugai et. al. The systematics agrees with experimental results. (author)

  19. Study of U235 neutron fission spectrum by the knowledge of cross sections average over that spectrum

    International Nuclear Information System (INIS)

    A literature search of cross sections averaged over the fission neutron spectrum confirms inconsistencies between calculated and experimental values for high threshold reactions. Since, in this case, calculated averaged cross sections are systematically lower than measured values, it is concluded that the representations used to carry out these calculations underestimate the number of neutrons in the high energy region of the spectrum. A careful measurement of the averaged cross section for the 45Sc(n,2n) 44gSc and 45Sc(n,2n) 44mSc high threshold reactions had been performed in the RA-6 Neutron Activation Analysis Laboratory after carefully checking that the neutron flux at the core position where the samples were being irradiated was indeed an undisturbed fission spectrum. The experimental values are greater than those calculated with either, Watt type representations or the one based on the Madland and Nix model for the prompt fission spectrum. In many areas of nuclear engineering, like validation of nuclear data, reactor calculations, applied nuclear physics, shielding design, etc., it is of great practical importance to have a representation for the neutron flux that can be expressed in a closed analytical form and that agrees with experimental results, specially for the most widely fissile nuclide, 235U. The results of the calculations mentioned above lead us to propose an analytical form for the 235U fission neutron spectrum that better agrees with experimental results in the whole energy spectrum. We propose two different forms; both are a modification of the Watt-type form that has been adopted within the ENDF/B-V files. One of the new analytical representations is defined in two regions: below 9.5 MeV it is exactly the same formula as that used within the ENDF/B-V files, above this energy the parameters of this formula are changed. The other proposed analytical representation is expressed by a single formula in the whole energy range. These two new

  20. Benchmarking of the FENDL-3 Neutron Cross-section Data Starter Library for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U., E-mail: ulrich.fischer@kit.edu [Association KIT-Euratom, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Angelone, M. [Associazione ENEA-Euratom, ENEA Fusion Division, Via E. Fermi 27, I-00044 Frascati (Italy); Bohm, T. [University of Wisconsin-Madison, 1500 Engineering Dr, Madison, WI 53706 (United States); Kondo, K. [Association KIT-Euratom, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Konno, C. [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Sawan, M. [University of Wisconsin-Madison, 1500 Engineering Dr, Madison, WI 53706 (United States); Villari, R. [Associazione ENEA-Euratom, ENEA Fusion Division, Via E. Fermi 27, I-00044 Frascati (Italy); Walker, B. [University of Wisconsin-Madison, 1500 Engineering Dr, Madison, WI 53706 (United States)

    2014-06-15

    This paper summarizes the benchmark analyses performed in a joint effort of ENEA (Italy), JAEA (Japan), KIT (Germany), and the University of Wisconsin (USA) on a computational ITER benchmark and a series of 14 MeV neutron benchmark experiments. The computational benchmark revealed a modest increase of the neutron flux levels in the deep penetration regions and a substantial increase of the gas production in steel components. The comparison to experimental results showed good agreement with no substantial differences between FENDL-3.0 and FENDL-2.1 for most of the responses. In general, FENDL-3 shows an improved performance for fusion neutronics applications.

  1. Benchmarking of the FENDL-3 Neutron Cross-section Data Starter Library for Fusion Applications

    International Nuclear Information System (INIS)

    This paper summarizes the benchmark analyses performed in a joint effort of ENEA (Italy), JAEA (Japan), KIT (Germany), and the University of Wisconsin (USA) on a computational ITER benchmark and a series of 14 MeV neutron benchmark experiments. The computational benchmark revealed a modest increase of the neutron flux levels in the deep penetration regions and a substantial increase of the gas production in steel components. The comparison to experimental results showed good agreement with no substantial differences between FENDL-3.0 and FENDL-2.1 for most of the responses. In general, FENDL-3 shows an improved performance for fusion neutronics applications

  2. Measurement of neutron inelastic scattering cross section of {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Takako; Baba, Mamoru; Ibaraki, Masanobu; Sanami, Toshiya; Win, Than; Hirasawa, Yoshitaka; Matsuyama, Shigeo; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan)

    1998-03-01

    Neutron scattering from the 0{sup +}, 2{sup +} (1-st) and 4{sup +} (2nd) levels of {sup 238}U was measured for incident energies between 0.4 and 0.85 MeV at the Tohoku University 4.5 MV Dynamitron facility, using the time-of-flight (TOF) method with monoenergetic pulsed neutrons by the {sup 7}Li(p,n) reaction. The results are presented in comparison with other experimental data and evaluated data. (author)

  3. Measurements of the Fe-54 (n,p) Mn-54 Reaction Cross Section in the Neutron Energy Range 2.3-3.8 MeV

    International Nuclear Information System (INIS)

    We have measured the 54Fe (n, p) 54Mn reaction cross section using a surface barrier detector to record the number of protons released in the reaction. The neutron flux was determined by means of a hydrogenous radiator, detecting the scattered protons with the solid state detector, and calculating the number of impinging neutrons from the well known n-p scattering cross section. The 54Fe (n, p) 54Mn reaction cross section is found to increase from 25 mb at 2.3 MeV to 208 mb at 3.5 MeV

  4. Importance of nuclear triaxiality for electromagnetic strength, level density and neutron capture cross sections in heavy nuclei

    CERN Document Server

    Grosse, Eckart; Massarczyk, Ralph

    2014-01-01

    Cross sections for neutron capture in the range of unresolved resonances are predicted simultaneously to level distances at the neutron threshold for more than 100 spin-0 target nuclei with A >70. Assuming triaxiality in nearly all these nuclei a combined parameterization for both, level density and photon strength is presented. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians adding up to the TRK sum rule and theory-based predictions for the A-dependence of pole energies and spreading widths. For the small spins reached by capture level densities are well described by only one free global parameter; a significant collective enhancement due to the deviation from axial symmetry is observed. Reliable predictions for compound nuclear reactions also outside the valley of stability as expected from the derived global parameterization are important for nuclear astrophysics and for the transmutation of nuclear waste.

  5. New time-of-flight data for the neutron capture cross-section of {sup 63}Cu

    Energy Technology Data Exchange (ETDEWEB)

    Weigand, M.; Reifarth, R. [Goethe Universitaet, Frankfurt (Germany); Bredeweg, T.A.; Couture, A.; Jandel, M.; O' Donnell, J.M.; Ullmann, J.L. [LANL, Los Alamos (United States)

    2014-07-01

    One of the important questions in nuclear astrophysics is how the observed abundances of elements came to be. Nearly all of the elements beyond the iron peak are either formed by the s- or the r-process in almost equal shares. The precise s-process path depends on stellar parameters like temperature and neutron density, and on nuclear parameters like half-lifes and neutron capture cross-sections (NCS). Thus, there is a big need for experimental data on the involved reactions to calculate their stellar rates to understand s-process nucleosynthesis. The NCS of the copper isotopes influences the isotopic ratios of Zn. Former experiments concerning the NCS of {sup 63}Cu showed large discrepancies. In order to determine the {sup 63}Cu(n,γ) cross-section in the astrophysical energy region, an experiment has been performed using the calorimetric 4π-BaF{sub 2} array DANCE at the Los Alamos National Lab (LANL). The results of the experiment will be presented.

  6. Neutron elastic scattering cross-sections measurement on carbon and fluorine in epithermal energy range using PEREN platform

    International Nuclear Information System (INIS)

    Molten Salt Reactor (MSR) based on Th/U cycle is one of the new generation concepts for nuclear energy production. A typical MSR is a graphite-moderated core with liquid fuel (7LiF +ThF4 + UF4). Many numerical studies based on Monte-Carlo codes are currently carried out but the validity of these numerical result relies on the precise knowledge of neutron cross sections used such as elastic scattering on carbon (σC), fluorine (σF) and lithium 7 (σLi). The goal of this work is to obtain σC and σF between 1 eV and 100 keV. Such measurements have been performed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC) de Grenoble on the experimental platform PEREN using slowing-down time spectrometers (C and CF2) associated to a pulsed neutron generator (GENEPI). Capture rates are obtained for reference materials (Au, Ag, Mo and In) using YAP scintillator coupled to a photo-multiplier. Very precise simulations (MCNP code) of the experimental setup have been performed and comparison with experiments has led to the determination of σC and σF with accuracies of 1% and 2% respectively. These results show a small discrepancy to evaluated nuclear data file (ENDF). Measures of total cross-sections σC and σF at higher energy (200 - 600 keV) were also carried out at Centre des Etudes Nucleaires de Bordeaux using a transmission method. Mono-energetic neutrons were produced by protons accelerated by a Van de Graaff accelerator on a LiF target and transmitted neutrons are counted in a proportional hydrogen gaseous detector. Discrepancies of 5% and 9% for σC and σF respectively with ENDF have been shown. (author)

  7. VIM4.0, Stead-State 3-D Neutron Transport Using ENDF/B or Multigroup Cross Sections

    International Nuclear Information System (INIS)

    1 - Description of program or function: VIM solves the steady-state neutron or photon transport problem in any detailed three-dimensional geometry using either continuous energy-dependent ENDF nuclear data or multigroup cross sections. Neutron transport is carried out in a criticality mode, or in a fixed source mode (optionally incorporating subcritical multiplication). Photon transport is simulated in the fixed source mode. The geometry options are infinite medium, combinatorial geometry, and hexagonal or rectangular lattices of combinatorial geometry unit cells, and rectangular lattices of cells of assembled plates. Boundary conditions include vacuum, specular and white reflection, and periodic boundaries for reactor cell calculations. The VIM 4.0 distribution includes data from ENDF/B-IV, ENDF/B-V, ENDF/B-VI and JEF2.2. Binary sequential data libraries for use with the code system on IBM or Sun workstations are included. ASCII data libraries and a convenient means to convert them to binary on a target machine are included for users on other systems. In addition to be included in the RSICC distribution files, the VIM User Guide is available on the developer's web site http://www.ra.anl.gov/vimguide/. 2 - Methods:VIM uses standard Monte Carlo methods for particle tracking with several optional variance-reduction techniques. These include splitting/Russian roulette, non-terminating absorption with non-analog weight cutoff energy. The keff is determined by the optimum linear combinations of two of the three eigenvalue estimates - analog, collision, and track length. Resonance and smooth cross sections are specified pointwise with linear-linear interpolation, frequently with many thousands of energy points. Unresolved resonances are described by the probability table method, which allows the statistical nature of the evaluated resonance cross sections to be incorporated naturally into self-shielding. Neutron interactions are elastic, inelastic and thermal scattering

  8. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

    CERN Document Server

    Belloni, F; Milazzo, P M; Calviani, M; Colonna, N; Mastinu, P; Abbondanno, U; Aerts, G; Álvarez, H; Álvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvár, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Koehler, P; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vazl, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.

  9. The fast neutron SEU cross section of a 4 Mb SRAM memory

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Evaldo C.F.; Goncalez, Odair L.; Cruz, Marco Aurelio da; Prado, Adriane Cristina Mendes; Federico, Claudio Antonio; Gaspar, Felipe de Barros, E-mail: claudiofederico@ieav.cta.br, E-mail: odairlelisgoncalez@gmail.com, E-mail: evaldocarlosjr@gmail.com, E-mail: adriane.acm@hotmail.com [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil)

    2013-07-01

    The results of a static test of single event upset (SEU) produced by fast neutrons on an ISSI 4Mb SRAM memory are reported in this work. To perform the tests, it was built a platform based on a motherboard which is controlled by microprocessor, whose function is to perform the writing, reading and control of the memories under irradiation. The irradiation was performed with a set of 8 {sup 241}Am-Be neutrons source in a quasi-isotropic incidence. The SEU cross was calculated from the accumulated bit flip count. (author)

  10. The fast neutron SEU cross section of a 4 Mb SRAM memory

    International Nuclear Information System (INIS)

    The results of a static test of single event upset (SEU) produced by fast neutrons on an ISSI 4Mb SRAM memory are reported in this work. To perform the tests, it was built a platform based on a motherboard which is controlled by microprocessor, whose function is to perform the writing, reading and control of the memories under irradiation. The irradiation was performed with a set of 8 241Am-Be neutrons source in a quasi-isotropic incidence. The SEU cross was calculated from the accumulated bit flip count. (author)

  11. Determination of the fission-neutron averaged cross sections of some high-energy threshold reactions of interest for reactor dosimetry

    CERN Document Server

    Arribere, M A; Ribeiro-Guevara, S; Korochinsky, S; Blostein, J J

    2003-01-01

    For three high threshold reactions, we have measured the cross sections averaged over a sup 2 sup 3 sup 5 U fission neutron spectrum. The measured reactions, and corresponding averaged cross sections found, are: sup 1 sup 2 sup 7 I(n,2n) sup 1 sup 2 sup 6 I, (1.36+-0.12) mb; sup 9 sup 0 Zr(n,2n) sup 8 sup 9 sup m Zr, (13.86+-0.83) mu b; and sup 5 sup 8 Ni(n,d+np+pn) sup 5 sup 7 Co, (274+-15) mu b; all referred to the well known standard of (111+-3) mb for the sup 5 sup 8 Ni(n,p) sup 5 sup 8 sup m sup + sup g Co averaged cross section. The measured cross sections are of interest in nuclear engineering for the characterization of the fast neutron component in the energy distribution of reactor neutrons. (author)

  12. New integral experiments for large angle scattering cross section data benchmarking with DT neutron beam at JAEA/FNS

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Seiki, E-mail: ohnishi@nmri.go.jp [National Maritime Research Institute, Mitaka, Tokyo (Japan); Kondo, Keitaro [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Azuma, Tetsushi [Kyoto University, Kumatori-cho, Osaka (Japan); Sato, Satoshi; Ochiai, Kentaro; Takakura, Kosuke [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Murata, Isao [Osaka University, Suita, Osaka (Japan); Konno, Chikara [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer We constructed a deuteron-triton fusion neutron beam. Black-Right-Pointing-Pointer A large SS316 cylinder assembly was irradiated by the neutron beam. Black-Right-Pointing-Pointer The reaction rates of activation foil were measured inside it. Black-Right-Pointing-Pointer The C/Es became smaller with the distance from the beam axis. Black-Right-Pointing-Pointer The large angle scattering cross section around 90 Degree-Sign affects that. - Abstract: A new integral experiment with a deuteron-triton fusion (DT) neutron beam started in order to validate scattering cross section data. First the DT neutron beam was constructed with a collimator. The performance of the collimator system and the characteristics of the DT neutron beam were measured. Second a new integral experiment for type 316 stainless steel (SS316) was carried out with this DT neutron beam. The DT neutron beam of 3.5 cm in diameter was injected to the front surface center of an SS316 cylindrical assembly. Reaction rates of the {sup 93}Nb(n,2n){sup 92m}Nb reaction in the assembly were measured with the activation foil method and were calculated with the Monte Carlo transport calculation code. The measurement points were located at three positions, on the center of the beam axis and at 15 cm and 30 cm apart from the axis. The ratio of calculation to experiment of the {sup 93}Nb(n,2n){sup 92m}Nb reaction rate became smaller than 1 with the distance from the beam axis. Then, the dependency of each reaction rate on scattering angle was calculated. It was proved that at off-axis positions, where C/E is smaller than 1, 90 Degree-Sign scattering contribute relatively larger than at on-axis positions and backward scattering made little contribution to the results in this experiment. The reasons of the discrepancy between the measured and calculated data will be investigated.

  13. Neutron Capture Cross Sections and Gamma Emission Spectra from Neutron Capture on 234,236,238U Measured with DANCE

    Science.gov (United States)

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

    2014-05-01

    A new measurement of the 238U(n, γ) cross section using a thin 48 mg/cm2 target was made using the DANCE detector at LANSCE over the energy range from 10 eV to 500 keV. The results confirm earlier measurements. Measurements of the gamma-ray emission spectra were also made for 238U(n, γ) as well as 234,236U(n, γ). These measurements help to constrain the radiative strength function used in the cross-section calculations.

  14. Neutron cross section measurements using the Oak Ridge electron linear accelerator

    International Nuclear Information System (INIS)

    This report discusses: n + 40Ar reactions; Neutron transmission measurement of n + 86Kr; state dependence of the optical potential 189Os and the s-process of stellar nucleosynthesis; and 122,123,124,124,126Te + n reactions. 4 refs., 9 figs

  15. The Weak s-Process in Massive Stars and its Dependence on the Neutron Capture Cross Sections

    Science.gov (United States)

    Pignatari, M.; Gallino, R.; Heil, M.; Wiescher, M.; Käppeler, F.; Herwig, F.; Bisterzo, S.

    2010-02-01

    The slow neutron capture process in massive stars (weak s process) produces most of the s-process isotopes between iron and strontium. Neutrons are provided by the 22Ne(α,n)25Mg reaction, which is activated at the end of the convective He-burning core and in the subsequent convective C-burning shell. The s-process-rich material in the supernova ejecta carries the signature of these two phases. In the past years, new measurements of neutron capture cross sections of isotopes beyond iron significantly changed the predicted weak s-process distribution. The reason is that the variation of the Maxwellian-averaged cross sections (MACS) is propagated to heavier isotopes along the s path. In the light of these results, we present updated nucleosynthesis calculations for a 25 M sun star of Population I (solar metallicity) in convective He-burning core and convective C-burning shell conditions. In comparison with previous simulations based on the Bao et al. compilation, the new measurement of neutron capture cross sections leads to an increase of s-process yields from nickel up to selenium. The variation of the cross section of one isotope along the s-process path is propagated to heavier isotopes, where the propagation efficiency is higher for low cross sections. New 74Ge, 75As, and 78Se MACS result in a higher production of germanium, arsenic, and selenium, thereby reducing the s-process yields of heavier elements by propagation. Results are reported for the He core and for the C shell. In shell C-burning, the s-process nucleosynthesis is more uncertain than in the He core, due to higher MACS uncertainties at higher temperatures. We also analyze the impact of using the new lower solar abundances for CNO isotopes on the s-process predictions, where CNO is the source of 22Ne, and we show that beyond Zn this is affecting the s-process yields more than nuclear or stellar model uncertainties considered in this paper. In particular, using the new updated initial composition, we

  16. Analysis of Different Uncertainty Activation Cross Section Data Libraries for LWR, ADS and DEMO Neutron Spectr

    Science.gov (United States)

    Díez, C. J.; Cabellos, O.; Martínez, J. S.

    2012-05-01

    This work is aimed to present the main differences of nuclear data uncertainties among three different nuclear data libraries: EAF-2007, EAF-2010 and SCALE-6.0, under different neutron spectra: LWR, ADS and DEMO (fusion). To take into account the neutron spectrum, the uncertainty data are collapsed to onegroup. That is a simple way to see the differences among libraries for one application. Also, the neutron spectrum effect on different applications can be observed. These comparisons are presented only for (n,fission), (n,gamma) and (n,p) reactions, for the main transuranic isotopes (234,235,236,238U, 237Np, 238,239,240,241Pu, 241,242m,243Am, 242,243,244,245,246,247,248Cm, 249Bk, 249,250,251,252Cf). But also general comparisons among libraries are presented taking into account all included isotopes. In other works, target accuracies are presented for nuclear data uncertainties; here, these targets are compared with uncertainties on the above libraries. The main results of these comparisons are that EAF-2010 has reduced their uncertainties for many isotopes from EAF-2007 for (n,gamma) and (n,fission) but not for (n,p); SCALE-6.0 gives lower uncertainties for (n,fission) reactions for ADS and PWR applications, but gives higher uncertainties for (n,p) reactions in all applications. For the (n,gamma) reaction, the amount of isotopes which have higher uncertainties is quite similar to the amount of isotopes which have lower uncertainties when SCALE-6.0 and EAF-2010 are compared. When the effect of neutron spectra is analysed, the ADS neutron spectrum obtained the highest uncertainties for (n,gamma) and (n,fission) reactions of all libraries.

  17. R-Matrix Evaluation of 16O Neutron Cross Sections up to 6.3 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.

    2000-08-21

    In this paper we describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes method, a generalized least squares technique. Over the years the nuclear community has developed a collection of evaluated nuclear data for applications in thermal, fast reactor, and fusion systems. However, typical neutron spectra in criticality safety applications are different from the spectra relevant to thermal, fast reactor, and fusion systems. In fact, the neutron spectra important for these non-reactor systems appear to peak in the epithermal energy range. Nuclear data play a major role in the calculation of the criticality safety margins for these systems. A thorough examination of how the present collection of nuclear data evaluations behaves in criticality safety calculations is needed. Many older evaluations will probably need to be revised, and new evaluations will be needed. Oxygen is an important element in criticality safety applications where oxides are present in significant abundance. The existing ENDF/B-VI.5 evaluation is expressed in terms of point-wise cross sections derived from the analysis of G. Hale [HA91]. Unfortunately such an evaluation is not directly useful for resonance analysis of data from samples in which oxygen is combined with other elements; for that purpose, Reich-Moore resonance parameters are needed. This paper addresses the task of providing those parameters. In the following sections we discuss the data, resonance analysis procedure, and results.

  18. Determination of the neutron resonance parameters for 206Pb and of the thermal neutron capture cross section for 206Pb and 209Bi

    International Nuclear Information System (INIS)

    Chapter 1 describes the motivation of the measurements (accelerator driven systems, stellar nucleosynthesis, neutron induced reactions on 206Pb), the present status of the neutron capture data for 206Pb and 209Bi and the structure of this work. In Chapter 2 the basic reaction theory underlying this work is described. The neutron induced reaction mechanism and formalism are explained. The parameterisation of the cross section in terms of R-matrix theory is discussed and we put particular emphasis on the statistical behaviour of the resonance parameters and the impact of the angular distribution of gamma rays following neutron capture. The relation between experimental observables and the resonance parameters is discussed together with general comments related to resonance shape analysis. Chapter 3 is focused on the determination of resonance parameters for 206Pb. We performed high-resolution transmission and capture measurements at the Time-Of-Flight (TOF) facility GELINA of the IRMM at Geel (B) and determined the resonance parameters. For nuclei like 206Pb, where the total width is dominated by Γn, the capture area allows to determine G. Transmission measurements were carried out to determine Γn, and the statistical factor g of resonances. Before performing a Resonance Shape Analysis (RSA) on the transmission and capture data, we verified the neutron flux and resolution at GELINA. We also compared the characteristics of GELINA with those of the n-TOF facility at CERN. A special emphasis is placed on the total energy detection technique using C6D6 detectors. This technique was applied for the determination of the capture cross section. To reduce systematic bias effects on the capture cross section, the response of the detectors was determined by Monte Carlo simulations, which has been validated by experiments. Using these response functions the partial capture cross sections for individual resonances of 206Pb have been deduced, by unfolding the response of the C6D

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

    Science.gov (United States)

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

    2014-03-01

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

  20. Distinction between Proton- and Neutron-Density Distributions of Halo Nuclei at the Nuclear Surface via Reaction Cross Sections

    Science.gov (United States)

    Nishimura, Daiki; Fukuda, M.; Takechi, M.; Mihara, M.; Ishikawa, D.; Matsuta, K.; Matsumiya, R.; Kuboki, T.; Suzuki, T.; Yamaguchi, T.; Hachiuma, I.; Namihira, K.; Ohtsubo, T.; Shinbara, Y.; Ohkuma, Y.; Izumikawa, T.; Tanaka, K.; Ozawa, A.; Yasuda, Y.; Moriguchi, T.; Momota, S.; Fukuda, S.; Sato, S.; Kanazawa, M.; Kitagawa, A.

    2009-10-01

    The halo and skin structures at the nuclear surface have attracted much interest for their exotic nature. By utilizing the isospin asymmetry of nucleon-nucleon total cross sections in the intermediate energy region, in principle, the proton- and neutron-density distributions can be determined independently. To demonstrate this isospin asymmetric effect, we have studied σR for the neutron-halo nucleus ^11 Be and the proton-halo nucleus ^8B on proton targets. We measured σR for ^11Be and ^8B on C and proton targets by the transmission method in the intermidiate energy region using HIMAC heavy ion synchrotron at NIRS. The present result for ^11Be is consistent with that the tail of ^11Be density consists of a neutron. On the other hand, the experimental result for ^8B is in agreement with the calculation with a proton tail in ^8B. Thus, the proton and neutron density distributions at the nuclear surface can be distinguished successfully by the σR on C and proton targets.

  1. Revision and extensions of neutron capture cross-sections in the European activation file EAF-3

    Energy Technology Data Exchange (ETDEWEB)

    Kopecky, J.; Delfini, M.G.; Kamp, H.A.J. van der; Nierop, D.

    1992-07-01

    This report contains an extensive description of the work performed to compile, extend and revise the neutron capture data subfile of the European Activation File (EAF-3). The starter was the EAF-1 data file from 1989. The present version, EAF/NG-3, contains (n, [gamma]) excitation functions for all nuclides (729 targets) with half-lives exceeding 1/2 day in the mass range from H-1 to Cm-248. (author). 35 refs.; 9 figs.; 7 tabs.

  2. Photofission cross sections of U-233 and Pu-239 near threshold induced by gamma-rays from thermal neutron capture

    International Nuclear Information System (INIS)

    The photofission cross sections of U-233 and PU-239 have been studied using monochromatic photons produced by thermal neutron capture in several materials placed in a radial beam hole of the IEA-R1, 2 MW pool type research reactor, in the energy interval from 5.43 MeV to 9.72 MeV. The gamma flux incident on the samples were measured using a (3X3) inch. NaI(Tl) crystal. The photofission fragments were detected in MAKROFOL-KG (solid state nuclear track detector) etched 30 min. in a KOH (35%wt) solution at 600C. The efficiency of the detector was obtained using a Californium-252 calibrated source and its value was (0.4323 ± 3%). The tracks were counted by means of an automatic spark counting. Analyzing the photofission data we have observed similarities between the cross sections obtained for the two samples in comparison with other authors. A structure was also observed in the U-233 cross section near the energy of 7.23 MeW. Acoording to the liquid drop model the height of the simple fission barrier were determined: (5.6 ± 0.2) MeV and (5.7 ± 0.2) MeV for U-233 and Pu-239 respectively. The relative fissionability of the samples to U-238 were also determined in each excitation energy and showed to be energy independent: (2.12 +-0.25) for U-233, and (3.32+-0.41) for Pu-239. (author)

  3. Calculated neutron-activation cross sections for E/sub n/ /le/ 100 MeV for a range of accelerator materials

    International Nuclear Information System (INIS)

    Activation problems associated with particle accelerators are commonly dominated by reactions of secondary neutrons produced in reactions of beam particles with accelerator or beam stop materials. Measured values of neutron-activation cross sections above a few MeV are sparse. Calculations with the GNASH code have been made for neutrons incident on all stable nuclides of a range of elements common to accelerator materials. These elements include B, C, N, O, Ne, Mg, Al, Si, P, S, Ar, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Nd, and Sm. Calculations were made for a grid of incident neutron energies extending to 100 MeV. Cross sections leading to the direct production of as many as 87 activation products for each of 84 target nuclide were tabulated on this grid of neutron energies, each beginning with the threshold for the product nuclide's formation. Multigrouped values of these cross sections have been calculated and are being integrated into the cross-section library of the REAC-2 neutron activation code. Illustrative cross sections are presented. 20 refs., 6 figs., 1 tab

  4. Gamma-ray production cross sections in multiple channels for neutron induced reaction on 48Ti for En=1 to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-06

    Prompt {gamma}-ray production cross sections were measured on a {sup 48}Ti sample for incident neutron energies from 1 MeV to 200 MeV. Partial {gamma}-ray cross sections for transitions in {sup 45-48}Ti, {sup 45-48}Sc, and {sup 43-45}Ca were determined. The observation of about 130 transitions from 11 different isotopes in the present work provides a demanding test of reaction model calculations, and is the first study in this mass region to extract partial {gamma}-ray cross sections for many different reaction channels over a wide range of incident neutron energies. The neutrons were produced by the Los Alamos National Laboratory spallation neutron source located at the LANSCE/WNR facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed GErmanium Array for Neutron Induced Excitations (GEANIE). Event neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections and then compared with model calculations using the enhanced GNASH reaction code. Compound nuclear, pre-equilibrium emission and direct reaction mechanisms are included. Overall the model calculations of the partial {gamma}-ray cross sections are in good agreement with measured values.

  5. Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Pigni, Marco T [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Leal, Luiz C [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten—namely, 182W(26.5%), 183W(14.31%), 184W(30.64%), and 186W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

  6. Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

    International Nuclear Information System (INIS)

    Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten - namely, 182W(26.5%), 183W(14.31%), 184W(30.64%), and 186W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

  7. Neutron capture cross-section of fission products in the European activation file EAF-3

    Energy Technology Data Exchange (ETDEWEB)

    Kopecky, J.; Delfini, M.G.; Kamp, H.A.J. van der; Gruppelaar, H.; Nierop, D. (Netherlands Energy Research Foundation (ECN), Petten (Netherlands))

    1992-05-01

    This paper contains a description of the work performed to extend and revise the neutron capture data in the European Activation File (EAF-3) with emphasis on nuclides in the fission-product mass range. The starter was the EAF-1 data file from 1989. The present version, EAF/NG-3, contains (n,[gamma]) excitation functions for all nuclides (729 targets) with half-lives exceeding 1/2 day in the mass range from H-1 to Cm-248. The data file is equipped with a preliminary uncertainty file, that will be improved in the near future. (author). 19 refs.; 5 figs.; 3 tabs.

  8. Neutron and gamma-ray emission double differential cross sections for the nuclear reaction by 1.5 GeV {pi}{sup +} incidence

    Energy Technology Data Exchange (ETDEWEB)

    Iga, Kiminori; Ishibashi, Kenji; Shigyo, Nobuhiro [Kyushu Univ., Fukuoka (Japan)] [and others

    1998-03-01

    Neutron and gamma-ray production double differential cross sections were measured for iron by the use of 1.5 GeV {pi}{sup +} mesons. The measured cross sections were compared with the calculated values by HETC-KFA2. For the neutrons, the calculated results deviate from the experimental data in the neutron energy region below 30 MeV. The calculated values of gamma-ray production agree with the experimental data at gamma-ray energies from 1 to 7 MeV within a factor of three. (author)

  9. Determination of 55Mn(n,γ) reaction cross-section at the neutron energies of 1.12 and 2.12 MeV

    International Nuclear Information System (INIS)

    In the present work, we determine the 55Mn(n,γ)56Mn reaction cross-section at the neutron energies of 1.12 and 2.12 MeV by using the off-line γ-ray spectrometric technique. The (n,γ) reaction cross-section 55Mn as a function of neutron energy was also calculated using nuclear reaction modular code TALYS-1.6 and compared with the present experimental data at 1.12 and 2.12 MeV as well as the literature data at other neutron energies

  10. Measurement of cross section of the {sup 98}Mo(n,γ){sup 99}Mo reaction using monochromatic thermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Md. Shuza; Hossain, Syed Mohammod; Zakaria, A.K.M.; Islam, Mohammod Amirul [Atomic Energy Research Establishment, Dhaka (Bangladesh). Inst. of Nuclear Science and Technology; Afroze, Nazmin [Atomic Energy Research Establishment, Dhaka (Bangladesh). Inst. of Nuclear Science and Technology; Jahangirnagar Univ., Dhaka (Bangladesh). Dept. of Physics

    2015-05-01

    The cross sections of the reaction {sup 98}Mo(n,γ){sup 99}Mo at neutron energies of 0.0334 eV and 0.0536 eV were measured for the first time using the activation technique, and the resulting values of 116 ± 7 mb and 91 ± 5 mb, respectively, are in good agreement with the JENDL-4 and ENDF/B-VII data files. Those measured values were extrapolated to the energy 0.0253 eV assuming 1/v dependence in the thermal region and the results were compared with the integrally measured values reported in the literature. The new data are thus useful to check the evaluated excitation function.

  11. Measurements of the induced gamma ray cross sections by 14. 2 MeV neutrons with Fe, Ni, Cu

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xiamin; Shen Ronglin; Xing Jinjiang; Wu Yongshun; Ding Dazhao

    1982-05-01

    The differential cross sections of the discrete gamma rays at 55/sup 0/ in the nuclear reactions of 14.2 MeV neutrons with Fe, Ni, Cu have been measured. The Ge (Li) semiconductor detector is enclosed in a heavy complete shielding. The relative efficiencies of full energy peaks and double peaks of the Ge (Li) detector are determined by the ''doubleline method'' in ..gamma.. energy region from 0.3 to 12 MeV and then normalized by a set of standard sources in order to determine the absolute efficiency. The linearity, stability and the effect of counting rate of the spectrometer have been checked.

  12. Simulation study of neutrino nucleus cross section measurement in a segmented detector at a spallation neutron source

    Institute of Scientific and Technical Information of China (English)

    YANG Zhen-Wei; DING Ming-Ming; CHEN Shao-Min; WANG Zhe; ZHANG Feng; GAO Yuan-Ning

    2012-01-01

    Knowledge ofνe-Fe/Pb differential cross sections for νe energy below several tens of MeV scale is believed to be crucial in understanding supernova physics.In a segmented detector at a spallation neutron source,νe energy reconstructed from the electron range measurement is strongly affected because both multiple scattering and electromagnetic showers occur along the electron passage in target materials.In order to estimate these effects,a simulation study has been performed with a cube block model assuming perfect tracking precision.The energy spectrum distortion is observed to be proportional to the atomic number of the target material.Feasibility of unfolding the distorted νe energy spectrum is studied for both Fe and Pb.An evaluation of the statistical accuracy attainable is therefore provided for a segmented detector.

  13. Development and benchmark of high energy continuous-energy neutron cross Section library HENDL-ADS/MC

    International Nuclear Information System (INIS)

    The ADS (accelerator driven sub-critical system) has great energy spans, complex energy spectrum structures and strong physical effects. Hence, the existing nuclear data libraries can't fully meet the needs of nuclear analysis in ADS. In order to do nuclear analysis for ADS system, a point-wise data library HENDL-ADS/MC (hybrid evaluated nuclear data library) was produced by FDS team. Meanwhile, to test the availability and reliability of the HENDL-ADS/MC data library, a series of shielding and critical safety benchmarks were performed. To validate and qualify the reliability of the high-energy cross section for HENDL-ADS/MC library further, a series of high neutronics integral experiments have been performed. The testing results confirm the accuracy and reliability of HENDL-ADS/MC. (authors)

  14. Cross sections of ground and isomeric states for (n,p) reaction on Sm-154 between 13.57 and 14.83MeV neutrons.

    Science.gov (United States)

    Reyhancan, Iskender Atilla

    2016-07-01

    In this study, the activation cross sections were measured for the (154)Sm(n,p)(154g)Pm, and (154)Sm(n,p)(154m)Pm reactions at several neutron energies between 13.57 and 14.83MeV, which were produced by the neutron generator (SAMES T-400) through the (3)H((2)H,n)(4)He reaction. The production of short-lived activity and the spectra accumulation were performed by the cyclic activation technique. Induced gamma-ray activities were measured using a high resolution gamma ray spectrometer equipped with a high-purity Germanium (HPGe) detector. In the cross section measurements, corrections were made regarding the effects of gamma-ray attenuation, dead-time, fluctuation of neutron flux, and low energy neutrons. The measured cross sections were compared with data reported in literature as well as model calculations using the code TALYS 1.6. PMID:27149398

  15. Neutron-induced fission cross section of (nat)Pb and (209)Bi from threshold to 1 GeV: An improved parametrization

    CERN Document Server

    Tarrio, D; Audouin, L; Berthier, B; Duran, I; Ferrant, L; Isaev, S; Le Naour, C; Paradela, C; Stephan, C; Trubert, D; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lederer, C; Lindote, A; Lopes, I; Losito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mendoza, E; Mengoni, A; Milazzo, P.M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Sarmento, R; Savvidis, I; Tagliente, G; Tain, J.L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross sections for (nat)Pb and (209)Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n\\_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to (235)U and (238)U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  16. European Collaboration for High-Resolution Measurements of Neutron Cross Sections between 1 MeV and 250 MeV

    CERN Multimedia

    Leal, L C; Kitis, G; Guber, K H; Yuasa nakagawa, K; Koehler, P E; Quaranta, A

    2002-01-01

    The experimental determination of neutron cross section data has always been of primary importance in Nuclear Physics. Many of the salient features of nuclear levels and densities can be determined from the resonant structure of such cross sections and of their decay scheme. An associated importance of precise neutron induced reaction cross sections has resulted from the worldwide interest in Accelerator Driven Systems (ADS) that has emerged at CERN and elsewhere. Many applications, such as accelerator-based transmutation of nuclear waste, energy amplification medical research, astrophysical applications and also fusion research require nuclear data that quantitatively and qualitatively go beyond the presently available traditional evaluation.\\\\ \\\\We consider a spallation driven TOF facility at the CERN-PS with an unprecedented neutron flux (1000 times the existing ones) in the broad energy range between 1 eV and 250 MeV and with very high energy resolution. The present concept for an intense neutron source m...

  17. Generation of neutron cross sections library for the Thermos code of the Fuel management System (FMS); Generacion de la biblioteca de secciones eficaces de neutrones para el codigo Thermos del sistema de administracion de combustible (FMS)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Viais J, J. [ININ, Gcia. Sistemas Nucleares, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1990-10-15

    There is developed a method to generate the library of neutron cross sections for the Thermos code by means of the database ENDF-B/IV and the NJOY code. The obtained results are compared with the version previous of the library of neutron cross sections which was processed using the version ENDF-B/III. (Author)

  18. Library of neutron cross sections of the Thermos code; Biblioteca de secciones eficaces de neutrones del codigo Thermos

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Hernandez L, H. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1991-10-15

    The present work is the complement of the IT.SN/DFR-017 report in which the structure and the generation of the library of the Thermos code is described. In this report the comparison among the values of the cross sections that has the current library of the Thermos code and those generated by means of the ENDF-B/NJOY it is shown. (Author)

  19. Au, Bi, Co and Nb cross-section measured by quasimonoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV

    Science.gov (United States)

    Majerle, M.; Bém, P.; Novák, J.; Šimečková, E.; Štefánik, M.

    2016-09-01

    Au, Bi, Co and Nb samples were irradiated several times with quasi-monoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV. The activities of the samples were measured with the HPGe detector and the reaction rates were calculated. The cross-sections were extracted using the SAND-II method with the reference cross-sections from the EAF-2010 database. The uncertainties of the final results are discussed.

  20. Measurement of neutron capture cross-section of the 71Ga(n, γ) 72Ga reaction at 0.0536 eV energy

    Science.gov (United States)

    Uddin, M. S.; Chowdhury, M. H.; Hossain, S. M.; Latif, Sk. A.; Hafiz, M. A.; Islam, M. A.; Zakaria, A. K. M.; Yunus, S. M.; Azharul Islam, S. M.

    2008-08-01

    The neutron capture cross-section for the 71Ga(n, γ) 72Ga reaction at 0.0536 eV energy was measured using activation technique based on TRIGA Mark-II research reactor. The 197Au(n, γ) 198Au monitor reaction was used to determine the effective neutron flux. Neutron absorption and γ-ray attenuation in gallium oxide pellet were corrected in determination of cross-section. The cross-section for the above reaction at 0.0536 eV amounts to 2.75 ± 0.14 b. As far as we know there are no experimental data available at our investigated energy. So far we are the first, who carried out experiment with 0.0536 eV neutrons for cross-section measurement. The present result is larger than that of JENDL-3.3, but consistent within the uncertainty range. The value of ENDF/B-VII is higher than this work. The result of this work will be useful to observe energy dependence of neutron capture cross-sections.

  1. Neutron capture cross section measurement of praseodymium in the energy region from 0.003 eV to 140 keV

    CERN Document Server

    Yoon, J; Lee, S; Yamamoto, S; Kobayashi, K

    2003-01-01

    The neutron capture cross section of praseodymium ( sup 1 sup 4 sup 1 Pr) has been measured relative to the sup 1 sup 0 B(n, alpha gamma) standard cross section in the energy region from 0.003 eV to 140 keV by the neutron time-of-flight (TOF) method with a 46-MeV electron linear accelerator (linac) of the Research Reactor Institute, Kyoto University (KURRI). An assembly of Bi sub 4 Ge sub 3 O sub 1 sub 2 (BGO) scintillators was used for the capture cross section measurement. In addition, the thermal neutron cross section (2,200 m/s value) of the sup 1 sup 4 sup 1 Pr(n, gamma) reaction has been also measured by an activation method at the heavy water thermal neutron facility of the Kyoto University Reactor (KUR). The thermal neutron flux was monitored with the sup 1 sup 9 sup 7 Au(n, gamma) sup 1 sup 9 sup 8 Au standard cross section. The above TOF measurement has been normalized to the current activation data (11.6+-1.3 b) at 0.0253 eV. The evaluated data in JENDL-3.3, ENDF/B-VI, and JEF-2.2 have been in gene...

  2. Critical analysis for nuclear data of thermal neutron capture cross section and the resonance integral from library based on neutron activation measurements

    International Nuclear Information System (INIS)

    For research reactor applications of neutron activation analysis, the evaluated neutron reaction cross sections and resonance integrals in some different libraries available were analyzed comparatively. In order to check these data, the thermal neutron capture cross section (σ0) and the resonance integral (I0) of 23Na(n, γ )24Na, 58Fe(n, γ) 59Fe, 59Co(n, γ )60Co, 27Al(n, γ )28Al, 109Ag(n, γ) 110mAg, 197Au(n, γ)198Au and 238U(n, γ )239U reactions from different libraries were used for comparative analysis with experimental measurements based on fundamental neutron activation equation. The targets were irradiated with neutrons in a research nuclear reactor 100 kW power, Triga Mark I. A high purity Ge detector was used for the gamma ray measurements of the irradiated samples. The evaluated results have been in general agreement with the current data according to different library sources. (author)

  3. {sup 48}Ti(n,xnpa{gamma}) reaction cross sections using spallation neutrons for E{sub n} = 1 to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dashdorj, D; Mitchell, G E; Garrett, P E; Agvaanluvsan, U; Becker, J A; Bernstein, L A; Cooper, J R; Hoffman, R D; Younes, W; Devlin, N; Fotiades, N; Nelson, R O

    2005-01-06

    {gamma}-ray excitation functions have been measured for the interaction of fast neutrons with {sup 48}Ti (neutron energy from 1 MeV to 250 MeV). The Los Alamos National Laboratory spallation neutron source, at the LANSCE/WNR facility, provided a ''white'' neutron beam which is produced by bombarding a natural W target with a pulsed proton beam. The prompt-reaction {gamma} rays were measured with the large-scale Compton-suppressed Ge spectrometer, GEANIE. Neutron energies were determined by the time-of-flight technique. Excitation functions were converted to partial {gamma}-ray cross sections, taking into account the dead-time correction, the target thickness, the detector efficiency, and neutron flux (monitored with an in-line fission chamber). The data analysis is presented here for neutron energies between 1 to 20 MeV. Partial {gamma}-ray cross sections for transitions in {sup 47,48}Ti, {sup 48}Sc, and {sup 45}Ca have been determined. These results are compared to Hauser-Feshbach predictions calculated using the STAPRE code, which includes compound nuclear and pre-equilibrium emission. The partial cross sections for {gamma} rays, whose discrete {gamma}-ray cascade path leads to the ground state in {sup 48}Ti, {sup 47}Ti, {sup 48}Sc, and {sup 45}Ca have been summed to obtain estimates of the lower limits for reaction cross sections. Partial cross sections for unobserved {gamma}-rays are predicted from the STAPRE code. These lower limits are combined with Hauser-Feshbach calculations to deduce {sup 48}Ti(n,n'){sup 48}Ti, {sup 48}Ti(n,2n){sup 47}Ti, {sup 48}Ti(n,p){sup 48}Sc, and {sup 48}Ti(n,{alpha}){sup 45}Ca reaction channel cross sections.

  4. Scattering chamber facility for double-differential cross-section measurement with 14 MeV DT neutron generator at IPR

    Indian Academy of Sciences (India)

    PRAJAPATI P M; PANDEY BHAWNA; GUPTA N C; KUMAR SURESH; NAYAK B K; SAXENA A; SURYANARAYANA S V; JAKHAR S; VALA SUDHIRSINH; RAO C V S; BASU T K

    2016-06-01

    Measurement of double-differential cross-sections of 14 MeV neutron-inducedcharged-particle productions is very important for estimating the nuclear heating and radiation damage of a fusion reactor. Only a few experimental data are available even though the nuclear reaction cross-section data of structural materials are important in fusion nuclear technology. In this context,general purpose scattering chamber facility has been developed for accelerator-based 14 MeV DT neutron generator to measure double-differential nuclear reaction cross-section at Fusion Neutronics Laboratory, IPR. It has been designed for experiments using silicon surface barrier detectors forthe online detection of charged particles. It offers flexibility in the arrangement of silicon surface barrier detectors.

  5. Neutron capture cross-section measurement for the 186W(n,gamma)187W reaction at 0.0536eV energy.

    Science.gov (United States)

    Uddin, M S; Chowdhury, M H; Hossain, S M; Latif, Sk A; Hafiz, M A; Islam, M A; Zakaria, A K M; Azharul Islam, S M

    2008-09-01

    The thermal neutron-induced activation cross section for the (186)W(n,gamma)(187)W reaction was measured at 0.0536eV neutron energy using TRIGA Mark-II research reactor, Atomic Energy Research Establishment, Savar, Dhaka, Bangladesh. The (197)Au(n,gamma)(198)Au monitor reaction induced in a high-purity gold foil was used to determine the effective neutron beam intensity. The activities induced in sample and monitor foils were measured nondestructively by a high-resolution HPGe gamma-ray detector. The present experimental cross-section value is the first one at 0.0536eV. The obtained new cross section that amounts to 26.6+/-1.6b is 2% higher than the recently reported data in ENDF/B-VII and 5% lower than that of JENDL-3.3. PMID:18325774

  6. 241 Am ( n ,γ) cross section in the neutron energy region between 0.02 eV and 300 keV

    Science.gov (United States)

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

    2008-04-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for a neutron capture cross section measurement on 241 Am . The high granularity of the DANCE array (160 BaF2 detectors in a 4π geometry) enables an efficient detection of prompt gamma rays following neutron capture. The preliminary results on the 241 Am ( n ,γ) cross section are presented from 0.02 eV to 300 keV. The cross section at thermal energy E n = 0.0253 eV was determined to be 665±33 barns. Resonance parameters were obtained using the SAMMY7 fit to the measured cross section in the resonance region. Significant discrepancies were found between our results and data evaluations for the first three lowest lying resonances. The cross section for neutrons with E n >l keV agrees well with the ENDF/B-VII.0 and JENDL-3.3 evaluations.

  7. 241Am(n,γ) cross section in the neutron energy region between 0.02 eV and 300 keV

    International Nuclear Information System (INIS)

    The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for a neutron capture cross section measurement on 241Am. The high granularity of the DANCE array (160 BaF2 detectors in a 4π geometry) enables an efficient detection of prompt gamma rays following neutron capture. The preliminary results on the 241Am(n,γ) cross section are presented from 0.02 eV to 300 keV. The cross section at thermal energy En = 0.0253 eV was determined to be 665±33 barns. Resonance parameters were obtained using the SAMMY7 fit to the measured cross section in the resonance region. Significant discrepancies were found between our results and data evaluations for the first three lowest lying resonances. The cross section for neutrons with En>l keV agrees well with the ENDF/B-VII.0 and JENDL-3.3 evaluations

  8. Self-consistent calculations of the strength function and radiative neutron capture cross section for stable and unstable tin isotopes

    CERN Document Server

    Goriely, S; Krewald, S

    2011-01-01

    The E1 strength function for 15 stable and unstable Sn even-even isotopes from A=100 till A=176 are calculated using the self-consistent microscopic theory which, in addition to the standard (Q)RPA approach, takes into account the single-particle continuum and the phonon coupling. Our analysis shows two distinct regions for which the integral characteristics of both the giant and pygmy resonances behave rather differently. For neutron-rich nuclei, starting from $^{132}$Sn, we obtain a giant E1 resonance which significantly deviates from the widely-used systematics extrapolated from experimental data in the $\\beta$-stability valley. We show that the inclusion of the phonon coupling is necessary for a proper description of the low-energy pygmy resonances and the corresponding transition densities for $A132$ region the influence of phonon coupling is significantly smaller. The radiative neutron capture cross sections leading to the stable $^{124}$Sn and unstable $^{132}$Sn and $^{150}$Sn nuclei are calculated wi...

  9. Study of fast neutron scattering. The displacement cross-section (1962); Etude de la diffusion des neutrons rapides. Section efficace de deplacement (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Millot, J.P. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1962-07-01

    We propose a method for calculating the biological efficiency of fast neutrons emitted by in-pile fission sources. This method justifies the empirical theory of Albert and Welton. In making simple assumptions concerning the cross-sections, we have supposed that the propagation can ben reduced to a mono-kinetic problem. A system of orthonormal functions is then set up making it possible to calculate the flux leaving a planar source. This method generalises the results obtained by Platzek to the case where the elastic cross-sections are not isotropic, and make it possible in particular to define a displacement cross-section: extension of the diffusion coefficient. This method can be generalised to the case of neutron diffraction as a function of time, and to the study of slowing-down. Numerical results are given in an appendix for the following: H{sub 2}O, D{sub 2}O, Fe, Be, Pb, CH, CH{sub 2}. These cross-sections have been verified experimentally in water and in graphite for neutrons of 2.5 and 14 MeV using a SAMES accelerator and a 2 MeV Van De Graaff. (author) [French] Nous proposons une methode permettant de calculer l'efficacite biologique des neutrons rapides issus des sources de fission dans la protection d'une pile. Cette methode justifie la theorie empirique d'Albert et Welton. En faisant des hypotheses simples sur les sections efficaces, nous avons suppose que la propagation pouvait etre ramenee a un probleme monocinetique. Nous construisons alors un systeme de fonctions orthonormales qui permet de calculer le flux issu d'une source plane. Cette methode generalise les resultats obtenus par Platzek au cas ou les sections efficaces elastiques ne sont pas isotropes et en particulier permet de definir une section efficace de deplacement: extension du coefficient de diffusion. Cette methode peut etre generalisee a la diffusion des neutrons en fonction du temps et a l'etude du ralentissement. Les resultats numeriques sont donnes en annexe

  10. Status report on multigroup cross section generation code development for high-fidelity deterministic neutronics simulation system.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W. S.; Lee, C. H. (Nuclear Engineering Division)

    2008-05-16

    Under the fast reactor simulation program launched in April 2007, development of an advanced multigroup cross section generation code was initiated in July 2007, in conjunction with the development of the high-fidelity deterministic neutron transport code UNIC. The general objectives are to simplify the existing multi-step schemes and to improve the resolved and unresolved resonance treatments. Based on the review results of current methods and the fact that they have been applied successfully to fast critical experiment analyses and fast reactor designs for last three decades, the methodologies of the ETOE-2/MC{sup 2}-2/SDX code system were selected as the starting set of methodologies for multigroup cross section generation for fast reactor analysis. As the first step for coupling with the UNIC code and use in a parallel computing environment, the MC{sup 2}-2 code was updated by modernizing the memory structure and replacing old data management package subroutines and functions with FORTRAN 90 based routines. Various modifications were also made in the ETOE-2 and MC{sup 2}-2 codes to process the ENDF/B-VII.0 data properly. Using the updated ETOE-2/MC{sup 2}-2 code system, the ENDF/B-VII.0 data was successfully processed for major heavy and intermediate nuclides employed in sodium-cooled fast reactors. Initial verification tests of the MC{sup 2}-2 libraries generated from ENDF/B-VII.0 data were performed by inter-comparison of twenty-one group infinite dilute total cross sections obtained from MC{sup 2}-2, VIM, and NJOY. For almost all nuclides considered, MC{sup 2}-2 cross sections agreed very well with those from VIM and NJOY. Preliminary validation tests of the ENDF/B-VII.0 libraries of MC{sup 2}-2 were also performed using a set of sixteen fast critical benchmark problems. The deterministic results based on MC{sup 2}-2/TWODANT calculations were in good agreement with MCNP solutions within {approx}0.25% {Delta}{rho}, except a few small LANL fast assemblies

  11. Validation Analyses of IEAF-2001 Activation Cross-Section Data for SS-316 and F82H Steels Irradiated in a White d-Li Neutron Field

    Science.gov (United States)

    Simakov, S. P.; Fischer, U.; v. Möllendorff, U.; Schmuck, I.; Tsige-Tamirat, H.; Wilson, P. P. H.

    2005-05-01

    The evaluated intermediate-energy activation cross-section library IEAF-2001 has been tested against integral experiments with SS-316 and F82H steels exposed to a white neutron flux spectrum extending up to 55 MeV. By making use of the ALARA inventory code the expected γ-active product nuclide inventories were calculated and compared with the measured one. It was found that IEAF-2001 reasonably agrees with experimental data for most of the detected radioisotopes. The reasons for some larger disagreements were found to be the uncertainty of the sample elemental composition, non-validated neutron activation reaction cross sections, and sequential charge particle reactions.

  12. O(n,xγ) reaction cross section for incident neutron energies between 6.5 and 20.0 MeV

    International Nuclear Information System (INIS)

    Differential cross sections for the neutron-induced gamma-ray production from oxygen were measured for incident neutron energies between 6.5 and 20.0 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons and a NaI spectrometer to detect the gamma rays at 1250. The data presented are the double differential cross section, d2sigma/dΩdE, for gamma-ray energies between 1.6 and 10.6 MeV for coarse intervals in incident neutron energy. The integrated yield for gamma rays of energies greater than 1.6 MeV with higher resolution in the neutron energy is also presented. The experimental results are compared with the Evaluated Nuclear Data File (ENDF). 34 references

  13. O(n,x. gamma. ) reaction cross section for incident neutron energies between 6. 5 and 20. 0 MeV. [Yield

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, G.L.; Chapman, G.T.

    1979-09-01

    Differential cross sections for the neutron-induced gamma-ray production from oxygen were measured for incident neutron energies between 6.5 and 20.0 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons and a NaI spectrometer to detect the gamma rays at 125/sup 0/. The data presented are the double differential cross section, d/sup 2/sigma/d..cap omega..dE, for gamma-ray energies between 1.6 and 10.6 MeV for coarse intervals in incident neutron energy. The integrated yield for gamma rays of energies greater than 1.6 MeV with higher resolution in the neutron energy is also presented. The experimental results are compared with the Evaluated Nuclear Data File (ENDF). 34 references.

  14. (n,2n) and (n,3n) cross sections of neutron-induced reactions on 150Sm for En from threshold to 35 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dashdorj, D; Mitchell, G; Kawano, T; Becker, J; Wu, C; Devlin, M; Fotiades, N; Nelson, R; Kunieda, S

    2009-03-16

    Cross-section measurements were made of prompt discrete {gamma}-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on a {sup 150}Sm sample fo 1550 mg/cm{sup 2} of Sm{sub 2}O{sub 3} enriched to 95.6% in {sup 150}Sm. Results are compared with enhanced Hauser-Feshbach model calculations including the pre-equilibrium reactions. Energetic neutrons were delivered by the Los Alamos Neutron Science Center facility. The prompt-reaction {gamma} rays were detected with the Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Incident neutron energies were determined by the time-of-flight technique. Excitation functions for thirteen individual {gamma}-rays up to E{sub x} = 0.8 MeV in {sup 149}Sm and one {gamma}-ray transition between the first excited and ground state in {sup 148}Sm were measured. Partial {gamma}-ray cross sections were calculated using GNASH, an enhanced Hauser-Feshbach statistical nuclear reaction model code, and compared with the experimental results. The particle transmission coefficients were calculated with new systematic 'global' optical model potential parameters. The coupled-channel optical model based on the soft rotor model was employed to calculate the particle transmission coefficients. The pre-equilibrium part of the spin distribution in {sup 150}Sm was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK) and incorporated into the GNASH reaction model code. the partial cross sections for discrete {gamma}-ray cascade paths leading to the ground state in {sup 149}Sm and {sup 148}Sm have been summed (without double counting) to estimate lower limits for reaction cross sections. These lower limits are combined with Hauser-Feshbach model calculations to deduce the reaction channel cross sections. These reaction channel cross sections agree with previously measured experimental and ENDF/B-VII evaluations.

  15. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

    Science.gov (United States)

    Pritychenko, B.; Mughabghab, S. F.

    2012-12-01

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

  16. Semi-empirical systematics of (n, 2n), (n, α) reactions cross sections at 14–15 MeV neutron energy

    International Nuclear Information System (INIS)

    In this study we propose new semi-empirical formulas by modifying the formula of Levkovskii with the new parameters for (n, 2n) and (n, α) reactions cross-sections at 14–15 MeV neutron incident energy. The cross sections have been calculated using the asymmetry parameter depending on empirical formulas for the incoming energies of 14–15 MeV neutrons. The parameters obtained by modifying the original formula of Levkovskii and Konno et al. have been determined by applying the least squares fitting method to the experimental cross sections, and the systematics of the (n, 2n) and (n, α) reactions have been studied. We have also suggested different parameters for the empirical formula to reproduce the cross sections of the (n, 2n) and (n, α) reactions for the neutron incident energy of 14–15 MeV. The modified formulas yielded cross sections representing markedly smaller chi-square (χ2) deviations from experimental values, and values much closer to units as compared with those calculated using Levkovskii's and Konno et al. original formulas. The results obtained have been discussed and compared with the other empirical formulas, and found to be well in agreement when used to correlate the available experimental σ(n, 2n) and σ(n, σ) data of different nuclei. (author)

  17. The influence of Isospin Dependence of In-Medium NN Cross Sections on the Ratio of Emitted Neutrons to Protons in HICs

    Institute of Scientific and Technical Information of China (English)

    JIA Yi-Jian; ZHANG Ying-Xun; LI Zhu-Xia; LU Xiao-Hua; LIU Fu-Hu

    2009-01-01

    The influence of isospin dependence of in-medium nucleon-nucleon cross sections on the n/p ratios for emitted nucleons in reactions 96Zr+6Zr and 96Ru+96Ru at Eb = 400 AMeV is investigated by means of an improved quantum molecular dynamics model. Our results show that the high energy part of the spectra of the n/p ratios for emitted nucleons is sensitive to the isospin dependence of in-medium nucleon-nucleon cross sections for neutron-rich reaction systems. Therefore, we propose that the n/p ratio of emitted high energy nucleons in a very neutron-rich reaction system at several hundreds of AMeV can be taken as sensitive observables to constrain the isospindependence of in-medium nucleon-nucleon cross sections.

  18. Updated Users' Guide for RSAP -- A Code for Display and Manipulation of Neutron Cross Section Data and SAMMY Fit Results

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, R.O.

    2003-07-29

    RSAP [1] is a computer code for display and manipulation of neutron cross section data and selected SAMMY output. SAMMY [2] is a multilevel R-matrix code for fitting neutron time-of-flight cross-section data using Bayes' method. This users' guide provides documentation for the recently updated RSAP code (version 6). The code has been ported to the Linux platform, and several new features have been added, including the capability to read cross section data from ASCII pointwise ENDF files as well as double-precision PLT output from SAMMY. A number of bugs have been found and corrected, and the input formats have been improved. Input items are parsed so that items may be separated by spaces or commas.

  19. Computed partial neutron cross-sections of 51V at 14 MeV for trace elemental analysis of biological samples

    International Nuclear Information System (INIS)

    The present paper describes the primary and secondary computed partial neutron reaction cross-sections at 14 MeV for 51V. The computations are based on the compound nucleus theory using an optical model potential and Newton's shell-dependent level density formula. The computed partial cross-sections have been compared with the available experimental values and are fairly in good agreement. These cross-sections have been used for the trace elemental analysis of biological samples like brain, muscle, liver, testes, lung, lymph nodes and blood of human subjects. The induced β-activity per gram of above biological samples per unit neutron flux have been computed for the reactions 51V(n,p)51Tisup(*) with Tsub(1/2)=5.8 min and 51V(n,α)48Scsup(*) with Tsub(1/2)=1.81 days and are tabulated. (author). 12 refs

  20. Inclusive cross section and single-transverse-spin asymmetry for very forward neutron production in polarized p+p collisions at sqrt(s)=200 GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aphecetche, L; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chang, B S; Chang, W C; Charvet, J -L; Chernichenko, S; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Citron, Z; Cole, B A; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Das, K; David, G; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durum, A; Dutta, D; Dzhordzhadze, V; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H -Å; Henni, A Hadj; Haggerty, J S; Hamagaki, H; Han, R; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Kawall, D; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, S H; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Klay, J; Klein-Boesing, C; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, K B; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Liebing, P; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mikeš, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niita, T; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J -C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reygers, K; Riabov, V; Riabov, Y; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Samsonov, V; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Seto, R; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Togawa, M; Toia, A; Tomášek, L; Tomita, Y; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, Y; Wei, F; Wessels, J; White, S N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zolin, L

    2012-01-01

    The energy dependence of the single-transverse-spin asymmetry, A_N, and the cross section for neutron production at very forward angles were measured in the PHENIX experiment at RHIC for polarized p+p collisions at sqrt(s)=200 GeV. The neutrons were observed in forward detectors covering an angular range of up to 2.2 mrad. We report results for neutrons with momentum fraction of x_F=0.45 to 1.0. The energy dependence of the measured cross sections were consistent with x_F scaling, compared to measurements by an ISR experiment which measured neutron production in unpolarized p+p collisions at sqrt(s)=30.6--62.7 GeV. The cross sections for large x_F neutron production for p+p collisions, as well as those in e+p collisions measured at HERA, are described by a pion exchange mechanism. The observed forward neutron asymmetries were large, reaching A_N=-0.08+/-0.02 for x_F=0.8; the measured backward asymmetries, for negative x_F, were consistent with zero. The observed asymmetry for forward neutron production is dis...

  1. Neutron capture cross section measurements of $^{238}$U, $^{241}$Am and $^{243}$Am at n_TOF

    CERN Multimedia

    Koehler, P E; Plag, R

    The increase of the world energy demand and the need of low carbon energy sources have triggered the renaissance and/or enhancement of nuclear energy in many countries. Fundamental nuclear physics can contribute in a practical way to the sustainability and safety of the nuclear energy production and the management of the nuclear waste. There exists a series of recent studies which address the most relevant isotopes, decay data, nuclear reaction channels and energy ranges which have to be investigated in more detail for improving the design of different advanced nuclear systems [1] and nuclear fuel cycles [2]. In this proposal, we aim at the measurement of the neutron capture cross sections of $^{238}$U, $^{241}$Am and $^{243}$Am. All three isotopes are listed in the NEA High Priority Request List [37], are recommended for measurements [1] and play an important role in the nuclear energy production and fuel cycle scenarios. The measurements will provide as well valuable nuclear structure data necessary for the...

  2. Dependence of the Ratio between the Resonance Integral and Thermal Neutron Cross Section on the Deviation of the Epithermal Neutron Spectrum from the 1/E Law

    International Nuclear Information System (INIS)

    In k0- Neutron Activation Analysis (k0-NAA), the conversion from the tabulated Q0 (ratio of the resonance integral to thermal neutron cross-section)to Q0(α) (α is the shape factor of the epithermal neutron flux, indicating the deviation of the epithermal neutron spectrum from the ideal 1/E shape) are calculated using a FORTRAN program. The calculations are done for most elements that can be detected by neutron activation using different values of the parameter (α) ranging from -0.1≤α≤+0.1. The obtained data are used to study the dependence of the values (α) on the irradiation position factor in (k0-NAA)equation for some selected isotopes differ in their resonance energy and its Q0 values. The results show that, the irradiation factor is affective mainly for low thermal tro epithermal flux ratio f especially for Q0 value greater than 50. so consequently determining the irradiation parameters α value is not needed for irradiation positions that rich with thermal neutron. But for high f values the irradiation position factor should be taken into account. On the other hand the constructed FORTRAN program can be used to calculate the value Q0 (α) directly for different value of α

  3. Neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu from 1 to 400 MeV

    International Nuclear Information System (INIS)

    Time-of-flight measurements of neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. 8 refs., 3 figs

  4. Measurement of neutron activation cross sections for major elements of water, air and soil between 30 and 70 MeV

    International Nuclear Information System (INIS)

    Neutron activation cross sections between 30 and 70 MeV were measured by the activation method using a semi-monoenergetic neutron field settled at the AVF cyclotron of the Cyclotron and Radioisotope Center (CYRIC), Tohoku University. Natural samples of N, O, Si, Na, Ca and Mg which are the major elements of water, air and soil were irradiated in this neutron field generated through the 7Li(p,n)7Be reaction by 30, 35, 40, 50, 60 and 70 MeV protons on thin Li target. Neutron yields were measured with the time-of-flight method using a calibrated NE213 organic liquid scintillator. From the induced activities measured with the HPGe detectors, we estimated the excitation functions of 15 cross sections. (author)

  5. Experimental determination of neutron capture cross sections of fast reactor structure materials integrated in intermediate energy spectra. Vol. 2: description of experimental structure

    International Nuclear Information System (INIS)

    A selection of technical documents is given concerning the experimental determination of the neutron capture cross-sections of fast reactor structural materials (Fe, Cr, Ni...) integrated over the intermediate energy spectra. The experimental structure project and modifications of the reactor RB2 for this experiment, together with criticality and safety calculations, are presented

  6. Development of an experimental set-up for the measurement of neutron-induced fission and capture cross sections of highly radioactive fissile nuclei

    Directory of Open Access Journals (Sweden)

    Companis Iulia

    2014-04-01

    Full Text Available The measurement of neutron-capture cross sections of many actinides is complicated by the difficulty in separating capture γ-rays from the large fission-fragment prompt γ-ray background. For example, current estimates of the capture cross section of 233U show large discrepancies, with differences of more than 20%. To improve the accuracy of data, a new experimental set-up for the simultaneous measurement of the neutron-induced capture and fission cross sections was designed, assembled and optimized. The measurements will be performed at the GEel LINear Accelerator (GELINA neutron time-of-flight facility in Belgium, where neutron cross sections can be measured over a wide energy range with high energy resolution. The fission detector consists of a dedicated multi-plate high-efficiency ionization chamber (IC. The γ-rays produced in capture reaction are detected by an array of C6D6 scintillators. Fission γ–rays are distinguished from capture γ–rays by the anticoincidence signals from the IC and the C6D6 detectors. For the undetected fission events a correction has to be applied based on the efficiency of the IC that should be high and known with a high accuracy. The performance of the IC during dedicated test experiments is presented, focusing on the determination of the detection efficiency.

  7. HADES. A computer code for fast neutron cross section from the Optical Model; HADES. Un programa numerico para el calculo de seccciones eficaces neutronicas mediante el modelo optico

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Navarro, C.

    1973-07-01

    A FORTRAN V computer code for UNIVAC 1108/6 using a local Optical Model with spin-orbit interaction is described. The code calculates fast neutron cross sections, angular distribution, and Legendre moments for heavy and intermediate spherical nuclei. It allows for the possibility of automatic variation of potential parameters for experimental data fitting. (Author) 55 refs.

  8. High energy neutron cross-sections and kerma values of biomedical interest calculated with a nuclear model applicable to light nuclei

    International Nuclear Information System (INIS)

    A model has been developed for calculating fast neutron cross sections (E > 14 MeV) for light nuclei of biomedical interest. The model explicitly includes experimental nuclear structure information. Some calculations for 12C, 14N, and 16O are presented

  9. Macroscopic cross sections of neutron radiation capture by Pb-208, U-238 and Tc-99 nuclides in the accelerator driven subcritical core cooled with molten Pb-208 - 286

    International Nuclear Information System (INIS)

    In the paper macroscopic cross sections for several isotopes: 208Pb, 238U, 99Tc and natural mix of lead isotopes, natPb, averaged over neutron spectra of the accelerator driven subcritical core cooled with natPb or 208Pb are given. It is shown that macro cross sections for a coolant from 208Pb are by 6.2 times smaller than those for the coolant consisted from natPb. The economy of neutrons in the core cooled with molten 208Pb can be used for reducing initial fuel load, increasing plutonium breeding and enhancing transmutation of such long lived fission products as 99Tc. The values of macro cross sections calculated for 238U and 99Tc, equal to 0.6 and 0.8 barns, respectively, are comparable with the values of the same nuclide macro cross sections for neutron spectrum of the fast reactor core cooled with sodium. Good neutron and physical features of molten 208Pb permit to assume it as perspective coolant for fast reactors and accelerator driven systems. (authors)

  10. Generation of the library of neutron cross sections for the Record code of the Fuel Management System (FMS); Generacion de la biblioteca de secciones eficaces de neutrones para el codigo Record del Sistema de Administracion de Combustible (FMS)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Hernandez L, H. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1991-11-15

    On the basis of the library structure of the RECORD code a method to generate the neutron cross sections by means of the ENDF-B/IV database and the NJOY code has been developed. The obtained cross sections are compared with those of the current library which was processed using the ENDF-B/III version. (Author)

  11. Design of a scattering chamber for double differential cross-section measurement with an accelerator based 14 MeV neutron generator

    International Nuclear Information System (INIS)

    The measurement of double-differential cross-sections (DDX) for the fast neutron induced charged particle reactions on fusion technology relevant structural materials are very important for estimating the level of nuclear heating, radiation damage in a reactor environment. Such reactions are induced on bombardment of fast neutrons on the first wall, structural, and blanket components of the reactor thereby leading to formation of gases (helium, hydrogen, deuterium etc.) in the bulk of materials

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

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, John Leonard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kawano, Toshihiko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bredeweg, Todd Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baramsai, Bayarbadrakh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haight, Robert Cameron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jandel, Marian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mosby, Shea Morgan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); O' Donnell, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vieira, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilhelmy, Jerry B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Becker, John A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wu, Ching-Yen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Krticka, Milan [Charles Univ., Prague (Czech Republic)

    2015-05-28

    Neutron capture cross sections in the “continuum” region (>≈1 keV) and gamma-emission spectra are of importance to basic science and many applied fields. Careful measurements have been made on most common stable nuclides, but physicists must rely on calculations (or “surrogate” reactions) for rare or unstable nuclides. Calculations must be benchmarked against measurements (cross sections, gamma-ray spectra, and <Γγ>). Gamma-ray spectrum measurements from resolved resonances were made with 1 - 2 mg/cm2 thick targets; cross sections at >1 keV were measured using thicker targets. The results show that the shape of capture cross section vs neutron energy is not sensitive to the form of the strength function (although the magnitude is); the generalized Lorentzian E1 strength function is not sufficient to describe the shape of observed gamma-ray spectra; MGLO + “Oslo M1” parameters produces quantitative agreement with the measured 238U(n,γ) cross section; additional strength at low energies (~ 3 MeV) -- likely M1-- is required; and careful study of complementary results on low-lying giant resonance strength is needed to consistently describe observations.

  13. Measurement of the neutron capture cross section of the s-only isotope 204Pb from 1 eV to 440 keV

    CERN Document Server

    Domingo-Pardo, C; Aerts, G; Alvarez-Pol, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Bisterzo, S; Calvino, F; Cano-Ott, D; Capote, R; Carrapico, C; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Gallino, R; Goncalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Kappeler, F; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P.M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; Oshima, M; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J.L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M.C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2007-01-01

    The neutron capture cross section of 204Pb has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range could be reliably determined from the measurement of a 208Pb sample. Other systematic effects in this measurement could be investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for 204Pb at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed.

  14. Cross sections of proton- and neutron-induced reactions by the Liège intranuclear cascade model

    Science.gov (United States)

    Chen, Jian; Dong, Tiekuang; Ren, Zhongzhou

    2016-06-01

    The purpose of the paper is mainly to test the validity of the Liège intranuclear cascade (INCL) model in calculating the cross sections of proton-induced reactions for cosmogenic nuclei using the newly compiled database of proton cross sections. The model calculations of 3He display the rising tendency of cross sections with the increase of energy, in accordance with the experimental data. Meanwhile, the differences between the theoretical results and experimental data of production cross sections (10Be and 26Al) are generally within a factor of 3, meaning that the INCL model works quite well for the proton-induced reactions. Based on the good agreement, we predict the production cross sections of 26Al from reactions n + 27Al, n + 28Si, and n + 40Ca and those of 10Be from reactions n + 16O and n + 28Si. The results also show a good agreement with a posteriori excitation functions.

  15. The indirect relationship between accuracy of the neutron cross section and the European market. Prospects for future

    International Nuclear Information System (INIS)

    The nuclear analytical techniques are peaceful tools which are applied since tens of years to material and environment analysis; they are under permanent consideration of the EC and IAEA Commissions for future developments together with objectives concerning security and safety. Neutron Activation Analysis (NAA) coupled with the high resolution γ-ray spectroscopy is one of the most powerful techniques designed to investigate composition of materials. The NAA applications, if carried out within the framework of a quality assurance system, gives confidence in the materials performance, which - in turn - contribute to development in social-economic and security fields (industry, medicine, environment control, forensic investigations, etc.). So, the nuclear activation tool is indirectly connected with the market of products and services; in turn, the NAA performance depends on the accuracy of the nuclear decay and reaction data. As the market will always need valid results, that request can be fulfilled only when the lowest measurement uncertainty of the element concentration, evaluated in accord to the GUM's recommendations is obtained. We demonstrated recently that the relative standardization procedure based on CRM samples provides the lowest uncertainty values and that the second reliable way is the internal standardization way based on k0,Au data. The thermal neutron activation and resonance integral cross section introduce too high uncertainty values (up to over 50% for a coverage factor k = 2), what can not be accepted on the market, as they introduce loss of precision and - by consequence - loss of quality and money. The NAA analysts in laboratories accredited in conformity with the Standard for competence are fully responsible on the results got for all of the analysed materials; it appears compulsory to help them by as high accurate as possible neutron activation data, as well as by production/certification of Reference Materials by accredited NAA European

  16. URR [Unresolved Resonance Region] computer code: A code to calculate resonance neutron cross-section probability tables, Bondarenko self-shielding factors, and self-indication ratios for fissile and fertile nuclides

    International Nuclear Information System (INIS)

    The URR computer code has been developed to calculate cross-section probability tables, Bondarenko self-shielding factors, and self-indication ratios for fertile and fissile isotopes in the unresolved resonance region. Monte Carlo methods are utilized to select appropriate resonance parameters and to compute the cross sections at the desired reference energy. The neutron cross sections are calculated by the single-level Breit-Wigner formalism with s-, p-, and d-wave contributions. The cross-section probability tables are constructed by sampling by Doppler broadened cross-sections. The various self-shielding factors are computer numerically as Lebesgue integrals over the cross-section probability tables

  17. MANTA. An Integral Reactor Physics Experiment to Infer the Neutron Capture Cross Sections of Actinides and Fission Products in Fast and Epithermal Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Youinou, Gilles Jean-Michel [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Neutron cross-sections characterize the way neutrons interact with matter. They are essential to most nuclear engineering projects and, even though theoretical progress has been made as far as the predictability of neutron cross-section models, measurements are still indispensable to meet tight design requirements for reduced uncertainties. Within the field of fission reactor technology, one can identify the following specializations that rely on the availability of accurate neutron cross-sections: (1) fission reactor design, (2) nuclear fuel cycles, (3) nuclear safety, (4) nuclear safeguards, (5) reactor monitoring and neutron fluence determination and (6) waste disposal and transmutation. In particular, the assessment of advanced fuel cycles requires an extensive knowledge of transuranics cross sections. Plutonium isotopes, but also americium, curium and up to californium isotope data are required with a small uncertainty in order to optimize significant features of the fuel cycle that have an impact on feasibility studies (e.g. neutron doses at fuel fabrication, decay heat in a repository, etc.). Different techniques are available to determine neutron cross sections experimentally, with the common denominator that a source of neutrons is necessary. It can either come from an accelerator that produces neutrons as a result of interactions between charged particles and a target, or it can come from a nuclear reactor. When the measurements are performed with an accelerator, they are referred to as differential since the analysis of the data provides the cross-sections for different discrete energies, i.e. σ(Ei), and for the diffusion cross sections for different discrete angles. Another approach is to irradiate a very pure sample in a test reactor such as the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after

  18. MANTA. An Integral Reactor Physics Experiment to Infer the Neutron Capture Cross Sections of Actinides and Fission Products in Fast and Epithermal Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Youinou, Gilles Jean-Michel [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Neutron cross-sections characterize the way neutrons interact with matter. They are essential to most nuclear engineering projects and, even though theoretical progress has been made as far as the predictability of neutron cross-section models, measurements are still indispensable to meet tight design requirements for reduced uncertainties. Within the field of fission reactor technology, one can identify the following specializations that rely on the availability of accurate neutron cross-sections: (1) fission reactor design, (2) nuclear fuel cycles, (3) nuclear safety, (4) nuclear safeguards, (5) reactor monitoring and neutron fluence determination and (6) waste disposal and transmutation. In particular, the assessment of advanced fuel cycles requires an extensive knowledge of transuranics cross sections. Plutonium isotopes, but also americium, curium and up to californium isotope data are required with a small uncertainty in order to optimize significant features of the fuel cycle that have an impact on feasibility studies (e.g. neutron doses at fuel fabrication, decay heat in a repository, etc.). Different techniques are available to determine neutron cross sections experimentally, with the common denominator that a source of neutrons is necessary. It can either come from an accelerator that produces neutrons as a result of interactions between charged particles and a target, or it can come from a nuclear reactor. When the measurements are performed with an accelerator, they are referred to as differential since the analysis of the data provides the cross-sections for different discrete energies, i.e. σ(Ei), and for the diffusion cross sections for different discrete angles. Another approach is to irradiate a very pure sample in a test reactor such as the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after

  19. Neutron capture cross section of $^{232}Th$ measured at the nTOF facility at CERN in the unresolved resonance region up to 1 MeV

    CERN Document Server

    Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, P A; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carillo de Albornoz, A; Cennini, P; Chepel, V Yu; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gonçalves, I; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F K; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2006-01-01

    We have measured the neutron capture reaction yield of /sup 232energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves script l=0,1, and 2.

  20. R-matrix analysis of the 241Pu neutron cross sections in the energy range thermal to 300 eV

    International Nuclear Information System (INIS)

    The report is a description of the analysis of the 241Pu neutron cross sections in the resolved resonance region at Oak Ridge National Laboratory (ORNL) using the multilevel-multichannel Reich-Moore code SAMMY. The resonance parameters were obtained in the energy range 0 to 300 eV. The table of the resonance parameters is given with some statistical properties of the parameters. Tabulated and graphical comparison between the experimental data and the calculated cross sections are given. The results are available in ENDF/B-V format and will be proposed for the evaluated data library JEF2 and ENDF/B-VI. 28 refs., 15 figs., 16 tabs

  1. The neutron capture cross sections of {sup 237}Np(n,{gamma}) and {sup 240}Pu(n,{gamma}) and its relevance in the transmutation of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, C.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kappeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    Neutron capture cross sections of actinides are of great relevance for the Transmutation of Nuclear Waste in Accelerator Driven Systems (ADS) and Generation-IV reactors. The neutron capture cross sections of {sup 237}Np and {sup 240}Pu in the range of 1 eV to 2 keV were measured at the n-TOF facility with a Total Absorption Calorimeter. The data have been analyzed with the SAMMY code. The corresponding covariance matrices have been generated. The final cross sections are presented and compared to the previously existing ones.The n-TOF {sup 237}Np {sigma}(n,{gamma}) is in agreement with the evaluated data files below 300 eV and its is lower by 10 to 15% up to 2 keV. This discrepancy with the evaluated data files is also observed in the capture cross section derived from the transmission measurements of Gressier et al. In the case of the {sup 240}Pu {sigma}(n,{gamma}), the n-TOF {sigma}(n,{gamma}) agrees within uncertainties with JENDL-3.3 and JEFF-3.1, except for a group of resonances around 800 eV. Endf/B-VII data are lower than n-TOF and the mentioned evaluations, with differences that increase with neutron energy up to 15-20 per cent.

  2. Search for halo nucleus in Mg isotopes through the measurements of reaction cross sections towards the vicinity of neutron drip line

    Directory of Open Access Journals (Sweden)

    Takechi M.

    2014-03-01

    Full Text Available Reaction cross sections (σR for 24–38Mg on C targets at the energies of around 240 MeV/nucleon have been measured precisely at RIBF, RIKEN for the purpose of obtaining the crucial information on the changes of nuclear structure in unstable nuclei, especially around the so-called “island of inversion” region. In the island of inversion region, which includes neutron-rich Ne, Na, and Mg isotopes, the vanishing of the N = 20 magic number for neutrons have been discussed along with nuclear deformation. The present result suggest deformation features of Mg isotopes and shows a large cross section of weakly-bound nucleus 37Mg, which could be caused by a neutron halo formation.

  3. Search for halo nucleus in Mg isotopes through the measurements of reaction cross sections towards the vicinity of neutron drip line

    International Nuclear Information System (INIS)

    Reaction cross sections (σR) for 24-38Mg on C targets at the energies of around 240 MeV/nucleon have been measured precisely at RIBF, RIKEN for the purpose of obtaining the crucial information on the changes of nuclear structure in unstable nuclei, especially around the so-called 'island of inversion' region. In the island of inversion region, which includes neutron-rich Ne, Na, and Mg isotopes, the vanishing of the N=20 magic number for neutrons have been discussed along with nuclear deformation. The present result suggests deformation features of Mg isotopes and shows a large cross section of weakly-bound nucleus 37Mg, which could be caused by a neutron halo formation. (authors)

  4. Measurement of the neutron capture cross-sections of Dy and Hf in the energy region from 0.003 eV to 50 keV

    CERN Document Server

    Cho, H J; Yamanoto, S; Fujita, Y; Kim, G Y; Ko, I S; Cho, M H; Namkung, W; Chang, J H; Ko, S K

    1999-01-01

    The capture cross-sections of Dy and Hf were measured in the energy region from 0.003 eV to 50 keV by using the neutron time-of-flight method at the 46 MeV electron linear accelerator of the Research Reactor Institute, Kyoto University. An assembly of Bi sub 4 Ge sub 3 O sub 1 sub 2 (BGO) scintillators, which was placed at a distance of 12.7 +- 0.02 m from the neutron source, was employed as a total absorption detector for the prompt capture gamma-ray measurement on the sample. In order to determine the neutron flux impinging on a capture sample, we used a Sm(n,gamma) reaction for thermal neutrons and the sup 1 sup 0 B(n,alpha gamma) reaction for neutrons from 0.003 eV to 50 keV. The absolute capture yield for the sample was obtained from the saturated resonance data at a large resonance of the sample. For the capture cross-section of Dy, the existing experimental data and the evaluated data in ENDF/B-VI and JEF-2.2 are closed to the present result. For the Hf capture cross-section, the previous experimental ...

  5. The PSIMECX medium-energy neutron activation cross-section library. Part 1: Description and procedures for use

    Energy Technology Data Exchange (ETDEWEB)

    Atchison, F.

    1998-09-01

    The PSIMECX library contains calculated nuclide production cross-sections from neutron-induced reactions in the energy range about 2 to 800 MeV in the following 72 stable isotopes of 24 elements: {sup 12}C, {sup 13}C, {sup 16}O, {sup 17}O, {sup 18}O, {sup 23}Na, {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 27}Al, {sup 28}Si, {sup 29}Si, {sup 30}Si, {sup 31}P, {sup 32}S, {sup 33}S, {sup 34}S, {sup 36}S, {sup 35}Cl, {sup 37}Cl, {sup 39}K, {sup 40}K, {sup 41}K, {sup 40}Ca, {sup 42}Ca, {sup 43}Ca, {sup 44}Ca, {sup 46}Ca, {sup 48}Ca, {sup 46}Ti, {sup 47}Ti, {sup 48}Ti, {sup 49}Ti, {sup 50}Ti, {sup 50}V, {sup 51}V, {sup 50}Cr, {sup 52}Cr, {sup 53}Cr, {sup 54}Cr, {sup 55}Mn, {sup 54}Fe, {sup 56}Fe, {sup 57}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 61}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 66}Zn, {sup 67}Zn, {sup 68}Zn, {sup 70}Zn, {sup 92}Mo, {sup 94}Mo, {sup 95}Mo, {sup 96}Mo, {sup 97}Mo, {sup 98}Mo, {sup 100}Mo, {sup 121}Sb, {sup 123}Sb, {sup 204}Pb, {sup 206}Pb, {sup 207}Pb, {sup 208}Pb, {sup 232}Th and {sup 238}U. The energy range covers essentially all transmutation channels other than capture. The majority of the selected elements are principal constituents of normal materials of construction used in and around accelerator facilities and the library is, first and foremost, designed to be a tool for the estimation of their activation in wide-band neutron fields. This first report, from a set of three, describes the form and usage of the library; the other two reports document the calculational methods. The present organisation of the library is the author's first idea and adequate for the intended use (activation calculations); being machine readable, translation of the library into other formats is straightforward. (author)

  6. Measurement of cross sections producing short-lived nuclei by 14MeV neutron. Cd, Sn, Te, Nd, Gd, Re

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.

    1998-03-01

    Nine neutron activation cross sections producing the nuclei with half-lives between 25sec and 22min were measured at energy range between 13.4 and 14.9 MeV by activation method. The (n,p) and (n,{alpha}) reaction cross sections were measured for the isotopes of {sup 110}Cd, {sup 112}Sn, {sup 122}Te, {sup 130}Te and {sup 185}Re and those of {sup 130}Te, {sup 148}Nd and {sup 158}Gd, respectively. The present results were compared with our systematics proposed on the basis of 58 cross section data of (n,p) and 33 data of (n,{alpha}) reaction. Good agreements have been seen between them. (author)

  7. Calculation and evaluation of cross-sections and kerma factors for neutrons up to 100 MeV on {sup 16}O and {sup 14}N

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B. [California Univ., Livermor, CA (United States). Lawrence Livermore National Lab.; Young, P.G.

    1997-03-01

    We present evaluations of the interaction of neutrons with energies between 20 and 100 MeV with oxygen and nitrogen nuclei, which follows on from our previous work on carbon. Our aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. We apply the FKK-GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. We determine total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra for light ejectiles with A {<=} 4 and gamma-rays, and average energy depositions. Our results for charged-particle emission spectra agree well with the measurements of Subramanian et al. We compare kerma factors derived from our evaluated cross sections with experimental data, providing an integral benchmarking of our work. (author). 52 refs.

  8. Neutron-induced fission cross-section of {sup 233}U in the energy range 0.5

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare (INFN), Legnaro (Italy); CERN, Geneva (Switzerland); Colonna, N.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Mastinu, P.; Gramegna, F. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [CEA, Irfu, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C. [Univ. de Santiago de Compostela, Santiago (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [Univ. of Lodz, Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Inst. fuer Kernphysik, Karlsruhe Inst. of Technology, Campus Nord, Karlsruhe (Germany); Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H.; Pigni, M.T. [Technische Univ. Wien, Atominstitut der Oesterreichischen Univ., Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [Centre National de la Recherche Scientifique/IN2P3 - IReS, Strasbourg (France); Becvar, F.; Krticka, M. [Charles Univ., Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Univ. Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Univ. de Sevilla, Sevilla (Spain); Carrapico, C.; Goncalves, I.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P. [Inst. Tecnologico e Nuclear, Lisbon (Portugal)] [and others

    2011-01-15

    The neutron-induced fission cross-section of {sup 233}U has been measured at the CERN n-TOF facility relative to the standard fission cross-section of {sup 235}U between 0.5 and 20MeV. The experiment was performed with a fast ionization chamber for the detection of the fission fragments and to discriminate against {alpha} -particles from the natural radioactivity of the samples. The high instantaneous flux and the low background of the n-TOF facility result in data with uncertainties of {approx} 3%, which were found in good agreement with previous experiments. The high quality of the present results allows to improve the evaluation of the {sup 233}U (n,f) cross-section and, consequently, the design of energy systems based on the Th/U cycle. (orig.)

  9. Cross sections for neutron capture from surrogate measurements: An examination of Weisskopf-Ewing and ratio approximations

    OpenAIRE

    Escher, Jutta E.; Dietrich, Frank S.

    2010-01-01

    Motivated by the renewed interest in the surrogate nuclear reactions approach, an indirect method for determining compound-nuclear reaction cross sections, the prospects for determining (n, gamma) cross sections for deformed rare-earth and actinide nuclei are investigated. A nuclear-reaction model is employed to simulate physical quantities that are typically measured in surrogate experiments and used to assess the validity of the Weisskopf-Ewing and ratio approximations, which are typically ...

  10. Measurement of the (n,2n) cross sections for 89Y, 93Nb, 103Rh, 107Ag, 169Tm, 175Lu and 197Au at 14.1 and 14.8 MeV incident neutron energies

    International Nuclear Information System (INIS)

    The (n,2n) cross sections for 89Y, 93Nb, 103Rh, 107Ag, 169Tm, 175Lu and 197Au have been measured at 14.1 and 14.8 MeV incident neutron energies. The samples were irradiated at the 14 MeV neutron generator of C.E. VALDUC. 27Al(n,α)24Na cross section was used for standard. The cross sections were obtained with an accuracy of about 5%

  11. Differential cross section measurement of the elastic neutron-deuteron-scattering in the energy range 2.5-30 MeV

    International Nuclear Information System (INIS)

    The differential cross-section of the elastic D(n, n)D scattering has been measured in the energy range 2.5-30 MeV. A pulsed 'white' neutron beam from deuterons (Esub(d) approx. equal to 48 MeV) on natural uranium was collimated by bulk metal shielding in a approx. equal to 60 m long vacuum tube in the THETAsub(LAB) = O0-direction. The collimated neutrons were scattered from a partially and a totally deuterated scintillator. The mixed scatterer of hydrogen, deuterium and carbon provided the absolute calibration of the (n, d)-cross-section by the well-known (n, p)-cross-section. The scattered neutrons were detected by two detectors at 14 laboratory angles. Five parameters for each event were measured in coincidence, so that background reduction could be done. Additional contributions from multiple-scattering were determined by Monte-Carlo calculations. Twenty angular distributions were obtained with uncertainties between 2 and 6%. Some significant deviations from older measurements and from exact 3-body-calculations were found. Much importance was attached to the determination of the properties of the neutron-detectors, especially of the so-called 'black-detector'. (orig.)

  12. Measurements of neutron-induced capture and fission reactions on $^{235}$ U: cross sections and ${\\alpha}$ ratios, photon strength functions and prompt ${\\gamma}$-ray from fission

    CERN Multimedia

    We propose to measure the neutron-induced capture cross section of the fissile isotope $^{235}$U using a fission tagging set-up. This new set-up has been tested successfully in 2010 and combines the n_TOF 4${\\pi}$ Total Absorption Calorimeter (TAC) with MicroMegas (MGAS) fission detectors. It has been proven that such a combination of detectors allows distinguishing with very good reliability the electromagnetic cascades from the capture reactions from dominant ${\\gamma}$-ray background coming from the fission reactions. The accurate discrimination of the fission background is the main challenge in the neutron capture cross section measurements of fissile isotopes. The main results from the measurement will be the associated capture cross section and ${\\alpha}$ ratio in the resolved (0.3-2250 eV) and unresolved (2.25-30 keV) resonance regions. According to the international benchmarks and as it is mentioned in the NEA High Priority Request List (HPRL), the 235U(n,${\\gamma}$) cross section is of utmost impo...

  13. Measurements of the neutron capture cross sections and incineration potentials of minor-actinides in high thermal neutron fluxes: Impact on the transmutation of nuclear wastes

    International Nuclear Information System (INIS)

    This thesis comes within the framework of minor-actinide nuclear transmutation studies. First of all, we have evaluated the impact of minor actinide nuclear data uncertainties within the cases of 241Am and 237Np incineration in three different reactor spectra: EFR (fast), GT-MHR (epithermal) and HI-HWR (thermal). The nuclear parameters which give the highest uncertainties were thus highlighted. As a result of fact, we have tried to reduce data uncertainties, in the thermal energy region, for one part of them through experimental campaigns in the moderated high intensity neutron fluxes of ILL reactor (Grenoble). These measurements were focused onto the incineration and transmutation of the americium-241, the curium-244 and the californium-249 isotopes. Finally, the values of 12 different cross sections and the 241Am isomeric branching ratio were precisely measured at thermal energy point. (author)

  14. Measurement of neutron-production double-differential cross-sections on carbon bombarded with 290-MeV/nucleon carbon and oxygen ions

    International Nuclear Information System (INIS)

    Neutron-production double-differential cross-sections on carbon-carbon and oxygen-carbon reactions with incident heavy-ion energy of 290 MeV/nucleon were measured by time-of-flight method using liquid organic scintillators. By use of a detection system specialized for low-energy neutrons, the cross-sections were obtained in a wide energy region from several hundred MeV down to 0.6 MeV for the oxygen-ion incidences. The experimental data were compared with the calculation results using the Monte-Carlo simulation code, PHITS. The PHITS results gave an overall agreement with the measured data within a factor of two.

  15. Measurement of the neutron-induced fission cross-section of {sup 241}Am at the time-of-flight facility n{sub T}OF

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); CERN, Geneva (Switzerland); Colonna, N.; Barbagallo, M.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Mastinu, P.; Gramegna, F. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Perrot, L.; Plukis, A. [Irfu, CEA, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C.; Tarrio, D. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [University of Lodz, Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Institut fuer Kernphysik, Karlsruhe Institute of Technology, Campus Nord, Nord (Germany); Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H. [Technische Universitaet Wien, Atominstitut der Oesterreichischen Universitaeten, Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [Centre National de la Recherche Scientifique/IN2P3 - IReS, Strasbourg (France); Becvar, F.; Krticka, M. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Universitat Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency (IAEA), Vienna (Austria); Universidad de Sevilla, Sevilla (Spain)] [and others

    2013-01-15

    The neutron-induced fission cross-section of {sup 241}Am has been measured relative to the standard fission cross-section of {sup 235}U between 0.5 and 20 MeV. The experiment was performed at the CERN n{sub T}OF facility. Fission fragments were detected by a fast ionization chamber by discriminating against the {alpha} -particles from the high radioactivity of the samples. The high instantaneous neutron flux and the low background of the n{sub T}OF facility enabled us to obtain uncertainties of {approx} 5%. With the present results it was possible to resolve discrepancies between previous data sets and to confirm current evaluations, thus providing important information for design studies of future reactors with improved fuel burn-up. (orig.)

  16. Re-evaluation of the neutron scattering dynamics in heavy water, generation of multigroup cross sections for THERM-126

    International Nuclear Information System (INIS)

    In providing THERM-126 with cross section matrices for deuterium bound in heavy water the IKE phonon spectrum was reevaluated. The changes are modifications in the acoustic part and in the frequency of the second oscillator. Contrary to the phonon spectrum model for D in D2O in ENDF/B-IV the broad band of hindered rotations is assumed to be temperature dependent taking into account the diffusive motion of the molecule. With the new model scattering law data S (α, β) are generated in the temperature range 293.6 K-673.6 K. The THERM-126 scattering cross section matrices are calculated up to P3. As a validity check a lot of differential and integral cross sections are compared to experiments and benchmarks are recalculated. (orig.)

  17. Cross sections for neutron capture from surrogate measurements: An examination of Weisskopf-Ewing and ratio approximations

    International Nuclear Information System (INIS)

    Motivated by the renewed interest in the surrogate nuclear reactions approach, an indirect method for determining compound-nuclear reaction cross sections, the prospects for determining (n,γ) cross sections for deformed rare-earth and actinide nuclei are investigated. A nuclear reaction model is employed to simulate physical quantities that are typically measured in surrogate experiments and used to assess the validity of the Weisskopf-Ewing and ratio approximations, which are typically employed in the analysis of surrogate reactions. The expected accuracy of (n,γ) cross sections extracted from typical surrogate measurements is discussed and limitations of the approximate methods are illustrated. Suggestions for moving beyond presently employed approximations are made.

  18. Measurements of (n,xp), (n,xd) double differential cross sections of Al and C for neutrons at 75 and 65 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nauchi, Yasushi; Baba, Mamoru; Iwasaki, Tomohiko [Tohoku Univ., Sendai (Japan). Faculty of Engineering] [and others

    1998-03-01

    The (n,xp) and (n,xd) double differential cross sections (DDXs) of Al and C were measured at 6 angles (12deg, 17deg, 25deg, 40deg, 55deg and 70deg) for neutrons En=65 and 75 MeV. These data are compared with theoretical calculations of ISOBAR and GNASH. A new wide range spectrometer under fabrication to down the detection threshold is also described. (author)

  19. Analysis of the Fission Cross-Section of U233 for Neutrons of Energies Between 1.7 and 30 eV

    International Nuclear Information System (INIS)

    The cross-section of U233 for resonance neutrons was analysed by the least-squares method. The paper discusses the need for using a multilevel formalism, and considers the statistical distributions of level spacing and partial widths. By the use of a study of level spacing as a starting point, particular attention is paid to the possibility of obtaining information on the relationship of populations of resonances of different spin. (author)

  20. Anomalous behavior of (n,α), (n,p) cross-section for 55Fe and 59Ni with low energy neutrons

    International Nuclear Information System (INIS)

    The objective of the present work is to study 55Fe(n,p) 59Ni(n,p), 55Fe(n,α), and 59Ni(n,α) reactions from the point of view of the prolific source of helium and hydrogen production not only at fast neutrons energy but also at lower energy. These reactions cannot be neglected at lower energy due to its very high cross-sections for He/H production inside the fusion reactor

  1. Indirect Measurement of 99Mo(n, γ) Cross-sections by 2 Neutron Transfer Reaction

    Institute of Scientific and Technical Information of China (English)

    FENG; Jing; YANG; Yi; LIU; Shi-long; WU; Xiao-guang; HU; Shi-peng; ZHONG; Jian; LI; Yun-ju; YAN; Sheng-quan; LI; Zhi-hong

    2013-01-01

    Aiming at acquiring the cross-sections for 99Mo(n,γ)by substitute reaction 98Mo(18O,16Oγ),the elastic scattering cross-sections for 16O+100Mo and 18O+98Mo systems are carefully measured on Q3D system of Tandem accelerator in China Institute of Atomic Energy at 90 MeV.Subsequently the interactive potentials for 16O+100Mo and 18O+98Mo systems are derived from the scattering.Finally,

  2. The impact of updated Zr neutron-capture cross sections and new asymptotic giant branch models on our understanding of the s process and the origin of stardust

    CERN Document Server

    Lugaro, Maria; Karakas, Amanda I; Milazzo, Paolo M; Kaeppeler, Franz; Davis, Andrew M; Savina, Michael R

    2013-01-01

    We present model predictions for the Zr isotopic ratios produced by slow neutron captures in C-rich asymptotic giant branch (AGB) stars of masses 1.25 to 4 Msun and metallicities Z=0.01 to 0.03, and compare them to data from single meteoritic stardust silicon carbide (SiC) and high-density graphite grains that condensed in the outflows of these stars. We compare predictions produced using the Zr neutron-capture cross section from Bao et al. (2000) and from n_TOF experiments at CERN, and present a new evaluation for the neutron-capture cross section of the unstable isotope 95Zr, the branching point leading to the production of 96Zr. The new cross sections generally presents an improved match with the observational data, except for the 92Zr/94Zr ratios, which are on average still substantially higher than predicted. The 96Zr/94Zr ratios can be explained using our range of initial stellar masses, with the most 96Zr-depleted grains originating from AGB stars of masses 1.8 - 3 Msun, and the others from either lowe...

  3. Thermal neutron capture cross-section measurements of 243Am and 242Pu using the new mini-INCA α- and γ-spectroscopy station

    International Nuclear Information System (INIS)

    In the framework of the Mini-INCA project, dedicated to the study of Minor Actinide transmutation process in high neutron fluxes, an α- and γ-spectroscopy station has been developed and installed at the High Flux Reactor of the Laue-Langevin Institut. This set-up allows short irradiations as well as long irradiations in a high quasi-thermal neutron flux and post-irradiation spectroscopy analysis. It is well suited to measure precisely, in reference to 59Co cross-section, neutron capture cross-sections, for all the actinides, in the thermal energy region. The first measurements using this set-up were done on 243Am and 242Pu isotopes. Cross-section values, at En=0.025eV, were found to be (81.8+/-3.6)b for 243Am and (22.5+/-1.1)b for 242Pu. These values differ from evaluated data libraries by a factor of 9% and 17%, respectively, but are compatible with the most recent measurements, validating by the way the experimental apparatus

  4. Measurement of the thermal cross section of the reaction 64Zn(n,γ)65Zn in a mixed neutron flux

    International Nuclear Information System (INIS)

    Zinc is an element that is present in a great variety of biological and geological samples.For its determination by Instrumental Neutron Activation Analysis, the reaction 64Zn(n,γ)65Zn is used, due to the long half life of the reaction product, the target's bigger isotopic abundance, and an easily measurable 1115 keV main gamma line.In a recent evaluation of thermal cross sections and resonance integrals, a thermal cross section value that is 44.7% bigger than the previous evaluation has been published by the same reference.This difference is not within reported uncertainties.Besides, the relative uncertainty of the new evaluation is much bigger than the one corresponding to the previous evaluation.The adoption of the thermal cross section corresponding to different evaluations may imply, in the case of an irradiation in the peripheral I 6 position at the R A-6 reactor, discrepancies of about 43% in the calculated concentrations.These inconsistencies were evident during the irradiation of certified standard materials.This motivated the measurement of the thermal cross section for the reaction 64Zn(n,γ)65Zn in the I 6 position at the R A-6 reactor.For the analysis of results, a code was written in order to calculate correction factors from an accurate characterization of the neutron spectrum.The thermal cross section value of the reaction 64Zn(n,γ)65Zn measured is (0.76± 0.03) b

  5. Cross-section measurements for (n, 2n) reactions on stannum isotopes in the neutron energy range of 13.5 to 14.6 MeV

    Institute of Scientific and Technical Information of China (English)

    PU Zhong-Sheng; YAN Dong; MA Jun; DU Xiao-Fang; GUAN Qiu-Yun

    2008-01-01

    Cross-sections for (n, 2n) reactions have been measured on stannum isotopes at the neutron energies of 13.5 to 14.6 MeV using the activation technique. Data are reported for the following reactions:112Sn(n, 2n)111Sn, 118Sn(n, 2n)117Sn and 124Sn(n, 2n)123mSn. The neutron fluences were determined using the monitor reaction 93Nb(n, 2n)92mNb or 27Al(n, α)24Na. The results of present work were compared with data published previously.

  6. HOTSPUR progress report: neutron source spectrum characterization, and 6Li(n,xα) and 7Li(n,xα) cross section determination

    International Nuclear Information System (INIS)

    As a prerequisite to high accuracy measurements involving the bulk configuration of 6LiD we must have a good grasp of the details of the RTNS-I neutron source energy spectrum. Experiments to this end involving neutron yield vs deuteron energy, ratios of foil activation of selected elements, and pulse height distributions of a Si surface barrier detector are described. With this knowledge, the 4He-production cross sections for 6Li and 7Li are found experimentally to be 0.512b and 0.336b, respectively, at anti E/sub N/ = 15.0 MeV in free-field geometry. 14 references

  7. Double differential charged particle emission cross sections of vanadium for 14.1 MeV incident neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kokooo; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan). Faculty of Engineering

    1997-03-01

    The double differential cross sections of V(n,xp) and V(n,x{alpha}) reactions have been measured by using the E-TOF spectrometer. The measured data were compared with other experimental data and evaluated nuclear data of JENDL Fusion-File. (author)

  8. Calculation of neutron cross sections for 90Zr, 208Pb and 209Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    International Nuclear Information System (INIS)

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides 90Zr, 208Pb and 209Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for 90Zr and Bechetti and Greenless for 208Pb and 209Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  9. Cross Section Measurements of Neutron Induced Reactions on GaAs using Monoenergetic Beams from 7.5 to 15 MeV

    Science.gov (United States)

    Raut, R.; Crowell, A. S.; Fallin, B.; Howell, C. R.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Kwan, E.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2011-09-01

    Cross section measurements for the neutron induced reactions on GaAs have been carried out at ten different neutron energies from 7.5 to 15 MeV, using the activation technique. The monoenergetic neutron beams were produced via the 2H(d,n)3He reaction, known for it's high neutron yield in the chosen energy regime. GaAs samples were activated along with the Au and Al monitor foils, for estimating the incident neutron flux. The induced activiy was measured using high resolution γ-ray spectroscopy. Five reaction channels viz., 69Ga(n, 2n) Ga, 69Ga(n,p)69mZn, 71Ga(n,p)71mZn, 75As(n, 2n)74As and 75As(n,p)75Ge, have been reported for the comprehensive cross section measurements. The results are compared with the existing literature data and the available evaluations. Statistical model calculations, based on the Hauser-Feshbach formalism, have been carried out using the TALYS and EMPIRE codes and are compared with the experimental values.

  10. ANSL-V: ENDF/B-V based multigroup cross-section libraries for Advanced Neutron Source (ANS) reactor studies. Supplement 1

    International Nuclear Information System (INIS)

    The original ANSL-V cross-section libraries (ORNL-6618) were developed over a period of several years for the physics analysis of the ANS reactor, with little thought toward including the materials commonly needed for shielding applications. Materials commonly used for shielding applications include calcium barium, sulfur, phosphorous, and bismuth. These materials, as well as 6Li, 7Li, and the naturally occurring isotopes of hafnium, have been added to the ANSL-V libraries. The gamma-ray production and gamma-ray interaction cross sections were completely regenerated for the ANSL-V 99n/44g library which did not exist previously. The MALOCS module was used to collapse the 99n/44g coupled library to the 39n/44g broad- group library. COMET was used to renormalize the two-dimensional (2- D) neutron matrix sums to agree with the one-dimensional (1-D) averaged values. The FRESH module was used to adjust the thermal scattering matrices on the 99n/44g and 39n/44g ANSL-V libraries. PERFUME was used to correct the original XLACS Legendre polynomial fits to produce acceptable distributions. The final ANSL-V 99n/44g and 39n/44g cross-section libraries were both checked by running RADE. The AIM module was used to convert the master cross-section libraries from binary coded decimal to binary format (or vice versa)

  11. Evaluation of cross sections and calculation of kerma factors for neutrons up to 80 MeV on {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Harada, M.; Watanabe, Y. [Kyushu Univ., Fukuoka (Japan); Chiba, S.; Fukahori, T.

    1997-03-01

    We have evaluated the cross sections for neutrons with incident energies from 20 to 80 MeV on {sup 12}C for the JENDL high-energy file. The total cross sections were determined by a generalized least-squares method with available experimental data. The cross sections of elastic and inelastic scattering to the first 2{sup +} were evaluated with the theoretical calculations. The optical potentials necessary for these calculations were derived using a microscopic approach by Jeukenne-Lejeune-Mahaux. For the evaluation of double differential emission cross sections (DDXs), we have developed a code system SCINFUL/DDX in which total 35 reactions including the 3-body simultaneous breakup process (n+{sup 12}C {yields} n+{alpha}+{sup 8}Be) can be taken into consideration in terms of a Monte Carlo method, and have calculated the DDXs of all light-emissions (A{<=}4) and heavier reaction products. The results for protons, deuterons, and alphas showed overall good agreement with experimental data. The code is also applicable for calculations of total and partial kerma factors. Total kerma factors calculated for energies from 20 to 80 MeV were compared with the measurements and the other latest evaluations from the viewpoints of medical application and nuclear heating estimation. (author)

  12. ANSL-V: ENDF/B-V based multigroup cross-section libraries for Advanced Neutron Source (ANS) reactor studies. Supplement 1

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.Q.; Renier, J.P.; Bucholz, J.A.

    1995-08-01

    The original ANSL-V cross-section libraries (ORNL-6618) were developed over a period of several years for the physics analysis of the ANS reactor, with little thought toward including the materials commonly needed for shielding applications. Materials commonly used for shielding applications include calcium barium, sulfur, phosphorous, and bismuth. These materials, as well as {sup 6}Li, {sup 7}Li, and the naturally occurring isotopes of hafnium, have been added to the ANSL-V libraries. The gamma-ray production and gamma-ray interaction cross sections were completely regenerated for the ANSL-V 99n/44g library which did not exist previously. The MALOCS module was used to collapse the 99n/44g coupled library to the 39n/44g broad- group library. COMET was used to renormalize the two-dimensional (2- D) neutron matrix sums to agree with the one-dimensional (1-D) averaged values. The FRESH module was used to adjust the thermal scattering matrices on the 99n/44g and 39n/44g ANSL-V libraries. PERFUME was used to correct the original XLACS Legendre polynomial fits to produce acceptable distributions. The final ANSL-V 99n/44g and 39n/44g cross-section libraries were both checked by running RADE. The AIM module was used to convert the master cross-section libraries from binary coded decimal to binary format (or vice versa).

  13. Measurement of the generation ratio of 233U and the average radiation capture cross section of 232Th with 232ThO2 irradiated by fast neutrons

    International Nuclear Information System (INIS)

    Background: Thorium-Uranium cycle plays an important role in the future's power production technology. Nuclear data involved are urgently needed for engineering design and other purposes since there are obvious differences between the existing evaluated data. Macroscopic neutron integral experiment can be used as a good tool to survey the confusion. Purpose: Macroscopic neutron integral experiment based on radioactive method was carried out to measure the generation ratio of 233U nuclide and the average radiation capture cross section of 232Th while a ThO2 sample was irradiated by fast neutrons leakage from a fast critical facility. We expect that these data can be used as a reference for the research of Th-U cycle. Methods: Radiation capture reactions of 232Th nuclides occur when the nuclides are irradiated by neutrons. 233U nuclides will be generated after two cascade decays by emitting beta rays from the activation products, which are 233Th nuclides. The ThO2 sample was prepared as a slice of 20 mm×10 mm from 0.743 36-g ThO2 powders of 99.9% enriched. The neutron flux was measured by activation method which was 4.07x109 cm-2·s-1 at the sample's irradiation position while the facility worked at the power level of 180 watts. The leakage neutrons' energy distribution was calculated by MC method and it is very close to the fission spectrum with the averaged energy of 1.42 MeV. After irradiation and then a period of cooling time the gamma rays emitted from the sample were measured by an HPGe spectrometer which had been pre-calibrated. From these data the activity of 233Pa was calculated and then the generation ratio of 233U and the average radiation capture cross section of 232Th were calculated. The measured average radiation capture cross section was compared with the cross sections calculated based on the ENDFB-VH.1, CENDL-3.1, JENDL-4.0, BROND2.2 databases. Results: The measured generation ratio of 233U was 4.01×10-12 with an uncertainty of 6

  14. Calculations of neutron and proton induced reaction cross sections for actinides in the energy region from 10MeV to 1GeV

    International Nuclear Information System (INIS)

    Several nuclear model codes were applied to calculations of nuclear data in the energy region from 10MeV to 1GeV. At energies up to 100MeV the nuclear theory code GNASH was used for nuclear data calculation for neutrons incident for on 238U, 233-236U, 238-242Pu, 237Np, 232Th, 241-243Am and 242-247Cm. At energies from 100MeV to 1GeV the intranuclear cascade exciton model including the fission process was applied to calculations of protons and neutrons with 233U, 235U, 238U, 232Th, 232Pa, 237Np, 238Np, 239Pu, 241Am, 242Am and 242-248Cm. Determination of parameter systematics was a major effort in the present work that was aimed at improving the predictive capability of the models used. An emphasis was placed upon a simultaneous analysis of data for a variety of reaction channels for the nuclei considered, as well as of data that are available for nearby nuclei or for other incident particles. Comparisons with experimental data available on multiple reaction cross sections, isotope yields, fission cross sections, particle multiplicities, secondary particle spectra, and double differential cross sections indicate that the calculations reproduce the trends, and often the details, of the measurements data. (author) 82 refs

  15. A new approach for precise measurements of keV neutron capture cross sections: The examples of 93Nb, 103Rh, and 181Ta

    International Nuclear Information System (INIS)

    A new experimental method has been implemented for precise measurements of neutron capture cross sections in the energy range from 3 to 200 keV. Neutrons are produced via the 7Li(p,n)7Be reaction using a pulsed 3 MV Van de Graaff accelerator. The neutron energy is determined by the time of flight technique using flight paths of less than 1 m. Capture events are detected with the Karlsruhe 4π Barium Fluoride Detector. This detector is characterized by a resolution in gamma-ray energy of 14% at 662 keV and 7% at 2.5 MeV, a time resolution of 500 ps, and a peak efficiency of 90% at 1 MeV. Capture events are registered with ≅ 95% probability above a gamma-ray threshold of 2.5 MeV. The combined effect of the relatively short primary flight path, the 10 cm inner radius of the detector sphere, and of the low capture cross section of BaF2 allows to discriminate the main background due to capture of sample scattered neutrons in the scintillator via time of flight, leaving part of the neutron energy range completely undisturbed. The high efficiency and good energy resolution for capture gamma-rays yields a further reduction of this background by using only the relevant energy channels for data evaluation. In the first measurements with the new detector, the neutron capture cross sections of 93Nb, 103Rh, and 181Ta were determined in the energy range from 3 to 200 keV relative to gold as a standard. The cross section ratios could be determined with overall systematic uncertainties of 0.7 to 0.8%; statistical uncertainties were less than 1% in the energy range from 20 to 100 keV, if the data are combined in 20 keV wide bins. The necessary sample masses were of the order of one gram. Further improvements with respect to sensitivity and accuracy are discussed. (orig.)

  16. Cross-section measurements of neutron-induced reactions on GaAs using monoenergetic beams from 7.5 to 15 MeV

    Science.gov (United States)

    Raut, R.; Crowell, A. S.; Fallin, B.; Howell, C. R.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Kwan, E.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2011-04-01

    Cross-section measurements for neutron-induced reactions on GaAs have been carried out at twelve different neutron energies from 7.5 to 15 MeV using the activation technique. The monoenergetic neutron beams were produced via the H2(d,n)He3 reaction. GaAs samples were activated along with Au and Al monitor foils to determine the incident neutron flux. The activities induced by the reaction products were measured using high-resolution γ-ray spectroscopy. Cross sections for five reaction channels, viz., Ga69(n,2n)Ga68, Ga69(n,p)Zn69m, Ga71(n,p)Zn71m, As75(n,2n)As74, and As75(n,p)Ge75, are reported. The results are compared with the previous measurements and available data evaluations. Statistical-model calculations, based on the Hauser-Feshbach formalism, have been carried out using the TALYS and the COH3 codes and are compared with the experimental results.

  17. Thulium-169 neutron inelastic scattering cross section measurements via the sup 1 sup 6 sup 9 Tm(n,n'gamma) reaction 25.40.fq; Inelastic neutron scattering; Nuclear reactions 169Tm(n,n'gamma); gamma-branching ratios; Neutron inelastic level cross sections; Compound and direct nuclear interaction; Time-of-flight method; High purity Ge detector

    CERN Document Server

    Ko, Y J; Kegel, G H R; Desimone, D J; Seo, P N; Young, P G

    2000-01-01

    Neutron inelastic scattering from thulium-169 has been studied for states above 100 keV via the (n,n'gamma) reaction at incident energies in the 0.2- to 1.0-MeV range. A high-resolution Ge spectrometer in conjunction with the time-of-flight technique was utilized. Thirty-six gamma-ray transitions from 16 levels were observed. Gamma-ray angular distributions were measured at E sub n =750 keV and excitation functions at 125 degrees were measured in 50 keV steps over the range of incident energies. Differential gamma-ray production cross sections and gamma-ray branching ratios were obtained. Inferred neutron inelastic level cross sections of the four lowest ground-state rotational band (K suppi=1/2 sup +) members are compared to the sum of calculated compound nucleus and direct interaction cross sections. For the remaining levels, measurements are compared to compound nucleus calculations only. The comparison shows generally good agreement particularly near threshold.

  18. Production cross sections of discrete gamma-ray resulting from interaction of 14. 2 MeV neutron with Pb and Bi

    Energy Technology Data Exchange (ETDEWEB)

    Wu Youngshun; Shen Ronglin; Shi Xiamin; Xing Jinqiang; Ding Dazhao

    1982-11-01

    The differential cross sections of gamma-rays produced in interation of 14.2 MeV neutron with natural lead and bismuth have been measured at 55/sup 0/ (lab). The complete shield Ge (Li) spectrometer with time-of-flight technique gated by associated particle in T(d,n) reaction was used. The gamma-ray spectra from 14.2 MeV neutron interactions with /sup 238/U and natural Tungsten have been measured as well. For Pb and Bi, tens of discrete gamma-rays were identified. Some of thme have not been reported in previous work. The effects of attenuation and multiple scattering of neutron and the gamma-ray self-absorption in sample are corrected by Monte-Carlo method. The experimental results are compared with others.

  19. Measurement of the Cross Section for Electromagnetic Dissociation with Neutron Emission in Pb-Pb Collisions at √sNN = 2.76 TeV

    CERN Document Server

    Abelev, Betty; Adamova, Dagmar; Adare, Andrew Marshall; Aggarwal, Madan; Aglieri Rinella, Gianluca; Agocs, Andras Gabor; Agostinelli, Andrea; Aguilar Salazar, Saul; Ahammed, Zubayer; Ahmad, Arshad; Ahmad, Nazeer; Ahn, Sang Un; Akindinov, Alexander; Aleksandrov, Dmitry; Alessandro, Bruno; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Almaraz Avina, Erick Jonathan; Alme, Johan; Alt, Torsten; Altini, Valerio; Altinpinar, Sedat; Altsybeev, Igor; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshauser, Harald; Arbor, Nicolas; Arcelli, Silvia; Arend, Andreas; Armesto, Nestor; Arnaldi, Roberta; Aronsson, Tomas Robert; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Awes, Terry; Aysto, Juha Heikki; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bailhache, Raphaelle Marie; Bala, Renu; Baldini Ferroli, Rinaldo; Baldisseri, Alberto; Baldit, Alain; Baltasar Dos Santos Pedrosa, Fernando; Ban, Jaroslav; Baral, Rama Chandra; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Barret, Valerie; Bartke, Jerzy Gustaw; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batyunya, Boris; Baumann, Christoph Heinrich; Bearden, Ian Gardner; Beck, Hans; Belikov, Iouri; Bellini, Francesca; Bellwied, Rene; Belmont-Moreno, Ernesto; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhati, Ashok Kumar; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Bjelogrlic, Sandro; Blanco, F; Blanco, Francesco; Blau, Dmitry; Blume, Christoph; Bock, Nicolas; Bogdanov, Alexey; Boggild, Hans; Bogolyubsky, Mikhail; Boldizsar, Laszlo; Bombara, Marek; Book, Julian; Borel, Herve; Borissov, Alexander; Bose, Suvendu Nath; Bossu, Francesco; Botje, Michiel; Bottger, Stefan; Boyer, Bruno Alexandre; Braidot, Ermes; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Browning, Tyler Allen; Broz, Michal; Brun, Rene; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Bugaiev, Kyrylo; Busch, Oliver; Buthelezi, Edith Zinhle; Caballero Orduna, Diego; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calvo Villar, Ernesto; Camerini, Paolo; Canoa Roman, Veronica; Cara Romeo, Giovanni; Carena, Francesco; Carena, Wisla; Carminati, Federico; Casanova Diaz, Amaya Ofelia; Castillo Castellanos, Javier Ernesto; Casula, Ester Anna Rita; Catanescu, Vasile; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Charvet, Jean-Luc Fernand; Chattopadhyay, Sukalyan; Chattopadhyay, Subhasis; Chawla, Isha; Cherney, Michael Gerard; Cheshkov, Cvetan; Cheynis, Brigitte; Chiavassa, Emilio; Chibante Barroso, Vasco Miguel; Chinellato, David; Chochula, Peter; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Coccetti, Fabrizio; Colamaria, Fabio; Colella, Domenico; Conesa Balbastre, Gustavo; Conesa del Valle, Zaida; Constantin, Paul; Contin, Giacomo; Contreras, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Cotallo, Manuel Enrique; Crochet, Philippe; Cruz Alaniz, Emilia; Cuautle, Eleazar; Cunqueiro, Leticia; D'Erasmo, Ginevra; Dainese, Andrea; Dalsgaard, Hans Hjersing; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Kushal; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; de Barros, Gabriel; De Caro, Annalisa; de Cataldo, Giacinto; de Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; de Rooij, Raoul Stefan; Del Castillo Sanchez, Eduardo; Delagrange, Hugues; Deloff, Andrzej; Demanov, Vyacheslav; Denes, Ervin; Deppman, Airton; Di Bari, Domenico; Di Giglio, Carmelo; Di Liberto, Sergio; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Dominguez, Isabel; Donigus, Benjamin; Dordic, Olja; Driga, Olga; Dubey, Anand Kumar; Ducroux, Laurent; Dupieux, Pascal; Dutta Majumdar, AK; Dutta Majumdar, Mihir Ranjan; Elia, Domenico; Emschermann, David Philip; Engel, Heiko; Erdal, Hege Austrheim; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Eyyubova, Gyulnara; Fabris, Daniela; Faivre, Julien; Falchieri, Davide; Fantoni, Alessandra; Fasel, Markus; Fearick, Roger Worsley; Fedunov, Anatoly; Fehlker, Dominik; Feldkamp, Linus; Felea, Daniel; Fenton-Olsen, Bo; Feofilov, Grigory; Fernandez Tellez, Arturo; Ferretti, Alessandro; Ferretti, Roberta; Figiel, Jan; Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Fragkiadakis, Michail; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Fusco Girard, Mario; Gaardhoje, Jens Joergen; Gagliardi, Martino; Gago, Alberto; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Garabatos, Jose; Garcia-Solis, Edmundo; Garishvili, Irakli; Gerhard, Jochen; Germain, Marie; Geuna, Claudio; Gheata, Andrei George; Gheata, Mihaela; Ghidini, Bruno; Ghosh, Premomoy; Gianotti, Paola; Girard, Martin Robert; Giubellino, Paolo; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez, Ramon; Gonzalez Ferreiro, Elena; Gonzalez-Trueba, Laura Helena; Gonzalez-Zamora, Pedro; Gorbunov, Sergey; Goswami, Ankita; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grajcarek, Robert; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoriev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grinyov, Boris; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerra Gutierrez, Cesar; Guerzoni, Barbara; Guilbaud, Maxime Rene Joseph; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Gutbrod, Hans; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harmanova, Zuzana; Harris, John William; Hartig, Matthias; Hasegan, Dumitru; Hatzifotiadou, Despoina; Hayrapetyan, Arsen; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Herrmann, Norbert; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hicks, Bernard; Hille, Per Thomas; Hippolyte, Boris; Horaguchi, Takuma; Hori, Yasuto; Hristov, Peter Zahariev; Hrivnacova, Ivana; Huang, Meidana; Humanic, Thomas; Hwang, Dae Sung; Ichou, Raphaelle; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Incani, Elisa; Innocenti, Gian Michele; Ippolitov, Mikhail; Irfan, Muhammad; Ivan, Cristian George; Ivanov, Andrey; Ivanov, Marian; Ivanov, Vladimir; Ivanytskyi, Oleksii; Jacholkowski, Adam Wlodzimierz; Jacobs, Peter; Jancurova, Lucia; Jangal, Swensy Gwladys; Janik, Malgorzata Anna; Janik, Rudolf; Jayarathna, Sandun; Jena, Satyajit; Jha, Deeptanshu Manu; Jimenez Bustamante, Raul Tonatiuh; Jirden, Lennart; Jones, Peter Graham; Jung, Hyung Taik; Jusko, Anton; Kakoyan, Vanik; Kalcher, Sebastian; Kalinak, Peter; Kalisky, Matus; Kalliokoski, Tuomo Esa Aukusti; Kalweit, Alexander Philipp; Kanaki, Kalliopi; Kang, Ju Hwan; Kaplin, Vladimir; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kazantsev, Andrey; Kebschull, Udo Wolfgang; Keidel, Ralf; Khan, Mohisin Mohammed; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Dong Jo; Kim, Do Won; Kim, Jonghyun; Kim, Jin Sook; Kim, Minwoo; Kim, Se Yong; Kim, Seon Hee; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Klay, Jennifer Lynn; Klein, Jochen; Klein-Bosing, Christian; Kliemant, Michael; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Koch, Kathrin; Kohler, Markus; Kolojvari, Anatoly; Kondratiev, Valery; Kondratyeva, Natalia; Konevskih, Artem; Korneev, Andrey; Kour, Ravjeet; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kramer, Frederick; Kraus, Ingrid Christine; Krawutschke, Tobias; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Krus, Miroslav; Kryshen, Evgeny; Krzewicki, Mikolaj; Kucheriaev, Yury; Kuhn, Christian Claude; Kuijer, Paul; Kurashvili, Podist; Kurepin, A; Kurepin, AB; Kuryakin, Alexey; Kushpil, Svetlana; Kushpil, Vasily; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Ladron de Guevara, Pedro; Lakomov, Igor; Langoy, Rune; Lara, Camilo Ernesto; Lardeux, Antoine Xavier; Lazzeroni, Cristina; Le Bornec, Yves; Lea, Ramona; Lechman, Mateusz; Lee, Ki Sang; Lee, Sung Chul; Lefevre, Frederic; Lehnert, Joerg Walter; Leistam, Lars; Lemmon, Roy Crawford; Lenhardt, Matthieu Laurent; Lenti, Vito; Leon Monzon, Ildefonso; Leon Vargas, Hermes; Leoncino, Marco; Levai, Peter; Lien, Jorgen; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Liu, Lijiao; Loenne, Per-Ivar; Loggins, Vera; Loginov, Vitaly; Lohn, Stefan Bernhard; Lohner, Daniel; Loizides, Constantinos; Loo, Kai Krister; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lovhoiden, Gunnar; Lu, Xianguo; Luettig, Philipp; Lunardon, Marcello; Luo, Jiebin; Luparello, Grazia; Luquin, Lionel; Luzzi, Cinzia; Ma, Rongrong; Maevskaya, Alla; Mager, Magnus; Mahapatra, Durga Prasad; Maire, Antonin; Mal'Kevich, Dmitry; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Ludmila; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Marin, Ana Maria; Marin Tobon, Cesar Augusto; Markert, Christina; Martashvili, Irakli; Martinengo, Paolo; Martinez, Mario Ivan; Martinez Davalos, Arnulfo; Martinez Garcia, Gines; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Mastromarco, Mario; Mastroserio, Annalisa; Matthews, Zoe Louise; Matyja, Adam Tomasz; Mayani, Daniel; Mayer, Christoph; Mazer, Joel; Mazzoni, Alessandra Maria; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Mercado Perez, Jorge; Meres, Michal; Miake, Yasuo; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz; Mitu, Ciprian Mihai; Mlynarz, Jocelyn; Mohanty, Ajit Kumar; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Monteno, Marco; Montes, Esther; Moon, Taebong; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Munhoz, Marcelo; Musa, Luciano; Musso, Alfredo; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Nattrass, Christine; Naumov, Nikolay; Navin, Sparsh; Nayak, Tapan Kumar; Nazarenko, Sergey; Nazarov, Gleb; Nedosekin, Alexander; Nicassio, Maria; Nielsen, Borge Svane; Niida, Takafumi; Nikolaev, Sergey; Nikolic, Vedran; Nikulin, Sergey; Nikulin, Vladimir; Nilsen, Bjorn Steven; Nilsson, Mads Stormo; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Novitzky, Norbert; Nyanin, Alexandre; Nyatha, Anitha; Nygaard, Casper; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Oleniacz, Janusz; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Ortona, Giacomo; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Pachmayer, Yvonne Chiara; Pachr, Milos; Padilla, Fatima; Pagano, Paola; Paic, Guy; Painke, Florian; Pajares, Carlos; Pal, S; Pal, Susanta Kumar; Palaha, Arvinder Singh; Palmeri, Armando; Papikyan, Vardanush; Pappalardo, Giuseppe; Park, Woo Jin; Passfeld, Annika; Patalakha, Dmitri Ivanovich; Paticchio, Vincenzo; Pavlinov, Alexei; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitri; Perez Lara, Carlos Eugenio; Perez Lezama, Edgar; Perini, Diego; Perrino, Davide; Peryt, Wiktor Stanislaw; Pesci, Alessandro; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petran, Michal; Petris, Mariana; Petrov, Plamen Rumenov; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Piccotti, Anna; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Pitz, Nora; Piuz, Francois; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Pluta, Jan Marian; Pocheptsov, Timur; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polichtchouk, Boris; Pop, Amalia; Porteboeuf-Houssais, Sarah; Pospisil, Vladimir; Potukuchi, Baba; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puchagin, Sergey; Puddu, Giovanna; Pujol Teixido, Jordi; Pulvirenti, Alberto; Punin, Valery; Putis, Marian; Putschke, Jorn Henning; Quercigh, Emanuele; Qvigstad, Henrik; Rachevski, Alexandre; Rademakers, Alphonse; Radomski, Sylwester; Raiha, Tomi Samuli; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Ramirez Reyes, Abdiel; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reichelt, Patrick; Reicher, Martijn; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riccati, Lodovico; Ricci, Renato Angelo; Richert, Tuva; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Rodrigues Fernandes Rabacal, Bartolomeu; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roed, Ketil; Rohr, David; Rohrich, Dieter; Romita, Rosa; Ronchetti, Federico; Rosnet, Philippe; Rossegger, Stefan; Rossi, Andrea; Roukoutakis, Filimon; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Ryabinkin, Evgeny; Rybicki, Andrzej; Sadovsky, Sergey; Safarik, Karel; Sahoo, Raghunath; Sahu, Pradip Kumar; Saini, Jogender; Sakaguchi, Hiroaki; Sakai, Shingo; Sakata, Dosatsu; Salgado, Carlos Albert; Salzwedel, Jai; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Sano, Satoshi; Santo, Rainer; Santoro, Romualdo; Sarkamo, Juho Jaako; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schreiner, Steffen; Schuchmann, Simone; Schukraft, Jurgen; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Patrick Aaron; Scott, Rebecca; Segato, Gianfranco; Selioujenkov, Ilya; Senyukov, Serhiy; Seo, Jeewon; Serci, Sergio; Serradilla, Eulogio; Sevcenco, Adrian; Sgura, Irene; Shabetai, Alexandre; Shabratova, Galina; Shahoyan, Ruben; Sharma, Natasha; Sharma, Satish; Shigaki, Kenta; Shimomura, Maya; Shtejer, Katherin; Sibiriak, Yury; Siciliano, Melinda; Sicking, Eva; Siddhanta, Sabyasachi; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, catherine; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Sinha, Bikash; Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Skjerdal, Kyrre; Smakal, Radek; Smirnov, Nikolai; Snellings, Raimond; Sogaard, Carsten; Soltz, Ron Ariel; Son, Hyungsuk; Song, Jihye; Song, Myunggeun; Soos, Csaba; Soramel, Francesca; Sputowska, Iwona; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Stefanini, Giorgio; Steinbeck, Timm Morten; Steinpreis, Matthew; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Stolpovskiy, Mikhail; Strabykin, Kirill; Strmen, Peter; Suaide, Alexandre Alarcon do Passo; Subieta Vasquez, Martin Alfonso; Sugitate, Toru; Suire, Christophe Pierre; Sukhorukov, Mikhail; Sultanov, Rishat; Sumbera, Michal; Susa, Tatjana; Szanto de Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szostak, Artur Krzysztof; Tagridis, Christos; Takahashi, Jun; Tapia Takaki, Daniel Jesus; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terrevoli, Cristina; Thader, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony; Tlusty, David; Toia, Alberica; Torii, Hisayuki; Tosello, Flavio; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ulery, Jason Glyndwr; Ullaland, Kjetil; Ulrich, Jochen; Uras, Antonio; Urban, Jozef; Urciuoli, Guido Marie; Usai, Gianluca; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; van der Kolk, Naomi; van Leeuwen, Marco; Vande Vyvre, Pierre; Vannucci, Luigi; Vargas, Aurora Diozcora; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vechernin, Vladimir; Veldhoen, Misha; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Vikhlyantsev, Oleg; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Viyogi, Yogendra; Vodopianov, Alexander; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; von Haller, Barthelemy; Vranic, Danilo; vrebekk, Gaute; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Vladimir; Wan, Renzhuo; Wang, Dong; Wang, Mengliang; Wang, Yifei; Wang, Yaping; Watanabe, Kengo; Wessels, Johannes; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Alexander; Wilk, Grzegorz Andrzej; Williams, Crispin; Windelband, Bernd Stefan; Xaplanteris Karampatsos, Leonidas; Yaldo, Chris G; Yang, Hongyan; Yang, Shiming; Yasnopolsky, Stanislav; Yi, JunGyu; Yin, Zhongbao; Yoo, In-Kwon; Yoon, Jongik; Yu, Weilin; Yuan, Xianbao; Yushmanov, Igor; Zach, Cenek; Zampolli, Chiara; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zaviyalov, Nikolai; Zbroszczyk, Hanna Paulina; Zelnicek, Pierre; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhou, Daicui; Zhou, Fengchu; Zhou, You; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zinovjev, Gennady; Zoccarato, Yannick Denis; Zynovyev, Mykhaylo

    2012-01-01

    The first measurement of neutron emission in electromagnetic dissociation of 208Pb nuclei at the LHC is presented. The measurement is performed using the neutron Zero Degree Calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN = 2.76 TeV with neutron emission are σ_single EMD = 187.2±0.2 (stat.) +13.8−12.0 (syst.) b and σ_mutual EMD = 6.2 ± 0.1 (stat.) ±0.4 (syst.) b respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.

  20. The neutron anomaly in the gamma N --> eta N cross section through the looking glass of the flavour SU(3) symmetry

    CERN Document Server

    Boika, T; Polyakov, M V

    2014-01-01

    We study the implications of the flavour SU(3) symmetry for various interpretations of the neutron anomaly in the $\\gamma N\\to\\eta N$ cross section. We show that the explanation of the neutron anomaly due to interference of known N(1535) and N(1650) resonances implies that N(1650) resonance should have a huge coupling to $\\phi$-meson -- at least 5 times larger than the corresponding $\\rho^0$ coupling. In terms of quark degrees of freedom this means that the well-known N(1650) resonance must be a "cryptoexotic pentaquark"-- its wave function should contain predominantly an $s\\bar s$ component. It turns out that the "conventional" interpretation of the neutron anomaly by the interference of known resonances metamorphoses into unconventional physics picture of N(1650).

  1. Slow neutron total cross-section, transmission and reflection calculation for poly- and mono-NaCl and PbF2 crystals

    Science.gov (United States)

    Mansy, Muhammad S.; Adib, M.; Habib, N.; Bashter, I. I.; Morcos, H. N.; El-Mesiry, M. S.

    2016-10-01

    A detailed study about the calculation of total neutron cross-section, transmission and reflection from crystalline materials was performed. The developed computer code is approved to be sufficient for the required calculations, also an excellent agreement has been shown when comparing the code results with the other calculated and measured values. The optimal monochromator and filter parameters were discussed in terms of crystal orientation, mosaic spread, and thickness. Calculations show that 30 cm thick of PbF2 poly-crystal is an excellent cold neutron filter producing neutron wavelengths longer than 0.66 nm needed for the investigation of magnetic structure experiments. While mono-crystal filter PbF2 cut along its (1 1 1), having mosaic spread (η = 0.5°) and thickness 10 cm can only transmit thermal neutrons of the desired wavelengths and suppress epithermal and γ-rays forming unwanted background, when it is cooled to liquid nitrogen temperature. NaCl (2 0 0) and PbF2 (1 1 1) monochromator crystals having mosaic spread (η = 0.5°) and thickness 10 mm shows high neutron reflectivity for neutron wavelengths (λ = 0.114 nm and λ = 0.43 nm) when they used as a thermal and cold neutron monochromators respectively with very low contamination from higher order reflections.

  2. Measurement of thermal neutron cross-section and resonance integral for the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction by the cadmium ratio method

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Mustafa [Gazi University, Gazi Education Faculty, Teknikokullar, 06500 Ankara (Turkey)], E-mail: mkaradag@gazi.edu.tr; Yuecel, Haluk [Turkish Atomic Energy Authority, Besevler Yerleskesi, Tandogan, 06100 Ankara (Turkey)

    2008-06-15

    The thermal-neutron cross-section and the resonance integral for the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction were measured by the activation method using a {sup 55}Mn monitor as single comparator. Analytical grade MnO{sub 2} and Yb{sub 2}O{sub 3} powder samples with and without a cylindrical 1 mm Cd shield box were irradiated in an isotropic neutron field obtained from three {sup 241}Am-Be neutron sources. The gamma-ray spectra from the activated samples were measured with a calibrated n-type high-purity Ge detector. The experimental results were corrected for the correction factors calculated for thermal and epithermal neutron self-shielding effects, epithermal neutron spectrum shape and gamma-ray self attenuation. Thus, the thermal neutron cross-section for the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction is found to be 126.5 {+-} 6.6 b, relative to that of the {sup 55}Mn monitor. The resonance integral value for the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction is found to be 59.6 {+-} 8.5 b, at cadmium cut-off energy of a 0.55 eV. Using the measured cadmium ratios of {sup 55}Mn and {sup 174}Yb, the result for resonance integral of the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction has also been obtained relative to the reference value of the {sup 55}Mn monitor. The present results for the {sup 174}Yb(n,{gamma}){sup 175}Yb reaction agree well only with the recent experimental ones obtained by Kafala et al. and De Corte and Simonits within uncertainty limits. However, the previously reported experimental data for the thermal neutron cross-section for this reaction are distributed between 24 and 141 b, and similarly the experimental values for the resonance integral value also show a large scatter in the range of 30-69 b.

  3. Re-evaluation of the $^{16}$O($n$,$\\gamma$)$^{17}$O cross section at astrophysical energies and its role as neutron poison in the $s$ process

    CERN Document Server

    Mohr, Peter; Pignatari, Marco; Dillmann, Iris; Mengoni, Alberto; Kaeppeler, Franz

    2016-01-01

    The doubly-magic nucleus $^{16}$O has a small neutron capture cross section of just a few tens of microbarn in the astrophysical energy region. Despite of this, $^{16}$O plays an important role as neutron poison in the astrophysical slow neutron capture ($s$) process due to its high abundance. We present in this paper a re-evaluation of the available experimental data for $^{16}$O($n,\\gamma$)$^{17}$O and derive a new recommendation for the Maxwellian-averaged cross sections (MACS) between $kT$= 5$-$100 keV. Our new recommendations are lower up to $kT$= 60 keV compared to the previously recommended values but up to 14\\% higher at $kT$= 100 keV. We explore the impact of this different energy dependence on the weak $s$-process during core helium- ($kT$= 26 keV) and shell carbon burning ($kT$= 90 keV) in massive stars where $^{16}$O is the most abundant isotope.

  4. Development of an experimental set-up for the measurement of neutron-induced fission and capture cross sections of radioactive fissile nuclei

    Directory of Open Access Journals (Sweden)

    Companis I.

    2013-12-01

    Full Text Available A new experimental set-up for a simultaneous measurement of neutron induced capture and fission cross sections was designed, assembled and optimized. The measurements will be performed at GEel LINear Accelerator (GELINA neutron time-of-flight facility in Belgium, where neutron cross sections can be measured over a wide energy range with high energy resolution. The fission events detector consists of a dedicated multi-plate high efficiency fission ionization chamber (IC. The γ-rays produced in capture reaction are detected by an efficient array of C6D6 scintillators. Fission γ-rays events are distinguished from capture events by the anticoincidence signals from the IC and the C6D6 detectors. For the undetected fission events a correction has to be applied with respect to the efficiency of the IC that should be high and known with a high precision. Another important issue is the good separation between fission-fragment (FF and the high alpha pile-up. The performances of the IC during test experiments are presented, focusing in particular on the detection efficiency.

  5. The impact of updated Zr neutron-capture cross sections and new asymptotic giant branch models on our understanding of the S process and the origin of stardust

    Energy Technology Data Exchange (ETDEWEB)

    Lugaro, Maria [Monash Centre for Astrophysics (MoCA), Monash University, Clayton, VIC 3800 (Australia); Tagliente, Giuseppe [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Karakas, Amanda I. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Milazzo, Paolo M. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Käppeler, Franz [Karlsruhe Institute of Technology, Campus North, D-76021 Karlsruhe (Germany); Davis, Andrew M. [The Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637 (United States); Savina, Michael R., E-mail: maria.lugaro@monash.edu, E-mail: giuseppe.tagliente@ba.infn.it, E-mail: amanda.karakas@anu.edu.au, E-mail: paolo.milazzo@ts.infn.it, E-mail: franz.kaeppeler@kit.edu, E-mail: a-davis@uchicago.edu, E-mail: msavina@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2014-01-01

    We present model predictions for the Zr isotopic ratios produced by slow neutron captures in C-rich asymptotic giant branch (AGB) stars of masses 1.25-4 M {sub ☉} and metallicities Z = 0.01-0.03, and compare them to data from single meteoritic stardust silicon carbide (SiC) and high-density graphite grains that condensed in the outflows of these stars. We compare predictions produced using the Zr neutron-capture cross sections from Bao et al. and from n{sub T}OF experiments at CERN, and present a new evaluation for the neutron-capture cross section of the unstable isotope {sup 95}Zr, the branching point leading to the production of {sup 96}Zr. The new cross sections generally present an improved match with the observational data, except for the {sup 92}Zr/{sup 94}Zr ratios, which are on average still substantially higher than predicted. The {sup 96}Zr/{sup 94}Zr ratios can be explained using our range of initial stellar masses, with the most {sup 96}Zr-depleted grains originating from AGB stars of masses 1.8-3 M {sub ☉} and the others from either lower or higher masses. The {sup 90,} {sup 91}Zr/{sup 94}Zr variations measured in the grains are well reproduced by the range of stellar metallicities considered here, which is the same needed to cover the Si composition of the grains produced by the chemical evolution of the Galaxy. The {sup 92}Zr/{sup 94}Zr versus {sup 29}Si/{sup 28}Si positive correlation observed in the available data suggests that stellar metallicity rather than rotation plays the major role in covering the {sup 90,} {sup 91,} {sup 92}Zr/{sup 94}Zr spread.

  6. Double differential cross section for neutron production in carbon-nucleus interactions at energies of 135-400 MeV/nucleon, obtained using the phenomenological NNEP method

    International Nuclear Information System (INIS)

    In this work we calculated the double differential cross sections for neutron production in 12C-A interactions on the basis of the phenomenological NNEP method and made their comparison with experimental data. Comparison was performed to verify the semi-empirical method for the experimental data and to determine the possibility of using the semi-empirical method for the prediction of radiation situation in the carbon-ion medical accelerator in the energy range of carbon ions 135-400 MeV/nucleon. There is a good agreement between the calculated and experimental data

  7. Measurement of the neutron-induced fission cross-section of {sup 243}Am relative to {sup 235}U from 0.5 to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); CERN, Geneva (Switzerland); Colonna, N.; Barbagallo, M.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Mastinu, P.; Gramegna, F. [Lab. Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [Irfu, CEA, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C.; Tarrio, D. [Univ. de Santiago de Compostela, Galicia (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [Univ. of Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Karlsruhe Inst. of Technology, Eggenstein-Leopoldshafen (Germany). Inst. fuer Kernphysik; Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H. [Technische Univ. Wien, Atominstitut der Oesterreichischen Universitaeten, Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [IReS, Centre National de la Recherche Scientifique/IN2P3, Strasbourg (France); Becvar, F.; Krticka, M. [Charles Univ., Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Univ. Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Univ. de Sevilla (Spain); Carrapico, C.; Goncalves, I.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P. [Inst. Tecnologico e Nuclear, Lisbon (Portugal)] [and others

    2011-12-15

    The ratio of the neutron-induced fission cross-sections of {sup 243}Am and {sup 235}U was measured in the energy range from 0.5 to 20 MeV with uncertainties of {approx} 4%. The experiment was performed at the CERN n{sub T}OF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up. (orig.)

  8. Extracting the cross section angular distributions for 15C high-energy resonance excited via the (18O,16O two-neutron transfer reaction

    Directory of Open Access Journals (Sweden)

    Carbone D.

    2016-01-01

    Full Text Available The 13C(18O,16O15C reaction has been studied at 84 MeV incident energy. The ejectiles have been momentum analized by the MAGNEX spectrometer and 15C excitation energy spectra have been obtained up to about 20 MeV. In the region above the two-neutron separation energy, a bump has been observed at 13.7 MeV. The extracted cross section angular distribution for this structure, obtained by using different models for background, displays a clear oscillating pattern, typical of resonant state of the residual nucleus.

  9. Development of 239Pu total cross section multilevel parameters determination technique by analysing experiments on neutron transmission in resolved resonance region

    International Nuclear Information System (INIS)

    The aim of this work is development of S-matrix multilevel resonance parameters determination technique with neutron transmission data used in resolved resonance region. Experimental transmission data values were obtained for the Pu-239 thickness range 0.00217-0.1234 nucl/barns on the time-of-flight spectrometer with 70 ns/m resolution. S-matrix Adler's formalism with least square method fit were used for experimental data description. The method developed enables to justify the resonance-resonance interference parameters H. Its possibilities are demonstrated by determination of these parameters for four resonances of the Pu-239 total cross section

  10. FEMA DFIRM Cross Sections

    Data.gov (United States)

    Minnesota Department of Natural Resources — FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally...

  11. Accuracy of the thermal neutron absorption cross section measurements (based on examples of selected pulsed beam methods); Dokladnosc pomiarow przekroju czynnego absorpcji neutronow termicznych (na przykladzie wybranych metod impulsowych)

    Energy Technology Data Exchange (ETDEWEB)

    Krynicka, E. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1997-12-31

    The problem of accuracy of the thermal neutron macroscopic absorption cross section determination is discussed on examples of selected measurement methods which use non-stationary neutron fields. The computer simulation method elaborated by the author is presented as a procedure for estimating the standard deviation of the measured absorption cross section. The computer simulation method presented can be easily utilized to estimate the accuracy of measurement of various physical magnitudes. (author) 46 refs, 3 figs, 1 tab

  12. URR [Unresolved Resonance Region] computer code: A code to calculate resonance neutron cross-section probability tables, Bondarenko self-shielding factors, and self-indication ratios for fissile and fertile nuclides

    International Nuclear Information System (INIS)

    The URR computer code has been developed to calculate cross-section probability tables, Bondarenko self-shielding factors, and self- indication ratios for fertile and fissile isotopes in the unresolved resonance region. Monte Carlo methods are utilized to select appropriate resonance parameters and to compute the cross sections at the desired reference energy. The neutron cross sections are calculated by the single-level Breit-Wigner formalism with s-, p-, and d-wave contributions. The cross-section probability tables are constructed by sampling the Doppler broadened cross-section. The various shelf-shielded factors are computed numerically as Lebesgue integrals over the cross-section probability tables. 6 refs

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

    Science.gov (United States)

    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.

  14. Measurement of 232Th(, ) and 232Th(, 2) cross-sections at neutron energies of 13.5, 15.5 and 17.28 MeV using neutron activation techniques

    Indian Academy of Sciences (India)

    Sadhana Mukerji; H Naik; S V Suryanarayana; S Chachara; B S Shivashankar; V Mulik; Rita Crasta; Sudipta Samanta; B K Nayak; A Saxena; S C Sharma; P V Bhagwat; K K Rasheed; R N Jindal; S Ganesan; A K Mohanty; A Goswami; P D Krishnani

    2012-08-01

    The 232Th(, ) reaction cross-section at average neutron energies of 13.5, 15.5 and 17.28 MeV from the 7Li(, ) reaction has been determined for the first time using activation and off-line -ray spectrometric technique. The 232Th(, 2) cross-section at 17.28 MeV neutron energy has also been determined using the same technique. The experimentally determined 232Th(, ) and 232Th(, 2) reaction cross-sections from the present work were compared with the evaluated data of ENDF/BVII and JENDL-4.0 and were found to be in good agreement. The present data, along with literature data in a wide range of neutron energies, were interpreted in terms of competition between 232Th(, ), (, ), (, ) and (, ) reaction channels. The 232Th(, ) and 232Th(, 2) reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were found to be in good agreement with the experimental data from the present work but were slightly higher than the literature data at lower neutron energies.

  15. Estimation of double differential angle-dependent neutron production cross sections from tritons on 197Au at energies from 5.97 to 19.14 MeV

    CERN Document Server

    Drosg, Manfred

    2016-01-01

    Estimated cross sections for neutron production from triton bombardment of gold are deduced from measurements of triton interactions with gas targets that used gold as a triton beam stop material. Differential cross sections for production of neutrons from 5.97-, 7.47-, 10.45-, 16.41- and 19.14-MeV tritons on 197Au were evaluated. Corrections for the neutron interaction in gold, in the target structure and in the air of the flight path were obtained by means of a Monte Carlo technique. Uncorrelated scale uncertainties range from 24 to 41% whereas those of double differential cross sections range from 0.2 to 5%. Based on these cross section data, calculation of neutron yield at 0o from fully stopped tritons at 20.22 MeV agree with an independent measurement. Least-squares fits with a gamma distribution model indicate an anisotropy in the high energy portion of the neutron spectra. Legendre polynomial fits of differential cross sections are reported. All neutron cross section data are made available through the...

  16. Neutron cross section measurements of water, heavy water, urine and blood for nutrition application; Medidas de secoes de choque para neutrons da agua leve, da agua pesada, urina e sangue para aplicacao em nutricao

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante Luiz; Oliveira Ferreira, Francisco J. de [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Pediatria e Puericultura Marzagao Gesteira

    1997-12-01

    The present work describes the application of a method developed at the reactor physics laboratory of IEN-CNEN-RJ for the determination of body water in subjects. The method is based on neutron cross section determinations of molecular compounds. It was used the crystal neutron spectrometer installed in J-9 channel irradiation of the Argonauta reactor. Hydrogenous and deuterated samples were measured to demonstrate the viability of the method. (author). 3 refs., 1 tab.

  17. Contribution to the study of nuclear structure using neutron total cross-section measurements between 400 and 1200 keV: isolated resonances and intermediate structure

    International Nuclear Information System (INIS)

    The neutron total cross sections have been measured over the energy range 400 keV - 1200 keV for fluorine, aluminium, silicon, phosphorus, vanadium, chromium, manganese, iron, nickel, cobalt and lead with an energy spread of 3 keV. The neutrons were produced by the T (p,n) 3He reaction, the proton beam was supplied by a 2 MeV Van de Graaff. The structure in 56Fe has been studied in a more detailed way by measuring six angular distributions in the above range and the elastic scattering excitation curves at four angles. The measurements have made it possible to show the existence of the compound nucleus, as well as the presence of an intermediate structure in certain nuclei. (author)

  18. Measurements of double differential charged particle emission cross sections and development of a wide range charged particles spectrometer for ten`s MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nauchi, Yasushi; Baba, Mamoru; Kiyosumi, Takehide [Tohoku Univ., Sendai (Japan). Faculty of Engineering] [and others

    1997-03-01

    We measured (n,xp), (n,xd) cross sections of C and Al for En=64.3 MeV neutrons at the {sup 7}Li(p,n) neutron sources facility at TIARA (Takasaki Establishment, JAERI) by using a conventional SSD-NaI telescope placed in the air. They show characteristic energy and angular dependence in high energy regions. In order to extend the measurements to low energy protons and {alpha} particles, a new spectrometer consisting of low pressure gas counters and BaF{sub 2} scintillators is now under development. A low threshold for low energy {alpha} particles will be achieved by using the gas counters. The particle identification over a wide energy range will be achieved by combining the {Delta}E-E method for low energy particles with the pulse shape discrimination (PSD) method of BaF{sub 2} for high energy particles. (author)

  19. Reaction Cross Section Calculations in Neutron Induced Reactions and GEANT4 Simulation of Hadronic Interactions for the Reactor Moderator Material BeO

    Directory of Open Access Journals (Sweden)

    Veli ÇAPALI

    2016-05-01

    Full Text Available BeO is one of the most common moderator material for neutron moderation; due to its high density, neutron capture cross section and physical-chemical properties that provides usage at elevated temperatures. As it’s known, for various applications in the field of reactor design and neutron capture, reaction cross–section data are required. The cross–sections of (n,α, (n,2n, (n,t, (n,EL and (n,TOT reactions for 9Be and 16O nuclei have been calculated by using TALYS 1.6 Two Component Exciton model and EMPIRE 3.2 Exciton model in this study. Hadronic interactions of low energetic neutrons and generated isotopes–particles have been investigated for a situation in which BeO was used as a neutron moderator by using GEANT4, which is a powerful simulation software. In addition, energy deposition along BeO material has been obtained. Results from performed calculations were compared with the experimental nuclear reaction data exist in EXFOR.

  20. Production of a {sup 44} Ti target and its cross section of thermal neutron capture; Producao de um alvo de {sup 44} Ti e sua secao de choque para captura de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Ejnisman, R

    1993-12-31

    A study of the production of a {sup 44} Ti target was carried out aiming the determination of its thermal neutron capture cross-section. With this purpose, the cross-section of the reaction {sup 45} Sc(p,2 n) {sup 44} Ti was determined in the energies 16-, 18-, 20-22- and 45 MeV. The cross-section of the reactions (p,n) {sup 45} Ti, (p,pn) {sup 44m} Sc, (p,pn) {sup 44g} Sc and (p,p2n){sup 43} Sc were also measured. The results in the low energy region are in good agreement with a previous work by McGee et al. On the other hand, the cross-section at 45 MeV is different from McGee`s result and indicates the existence of an abnormal behavior of the excitation function at higher energies. Furthermore, a radiochemical separation method was developed in order to eliminate Sc from the {sup 44} Ti target which was irradiated with neutrons. It was possible to determine an upper limit for the cross-section of the reaction {sup 44} Ti (n, {gamma}) of 4 x 10{sup 3} b. At last, it is presented a discussion of the results obtained and their possible astrophysical implications. (author) 94 refs.