Neutron-capture cross-sections of 244Cm and 246Cm measured with an array of large germanium detectors in the ANNRI at J-PARC/MLF

The neutron neutron-capture cross cross-sections of 244Cm and 246Cm were measured by the time-of-flight method in the energy range of 1–300 300 eV with an array of large germanium detectors in the Accurate Neutron-Nucleus Reaction measurement InstrumentANNRI at Material and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research ComplexJ-PARC/MLF. The 244Cm resonances at around 7.7 and 16.8 8 eV and the 246Cm resonances at around 4.3 and 15.3 3 eV were observed in the capture reactions for the first time. The uncertainties of the obtained cross cross-sections are 5.8% at the top of the first resonance of 244Cm and 6.6% at that of 246Cm. The rResonance analyses were performed for low-energy ones using the code SAMMY. The prompt γ-ray spectra of 244Cm and 246Cm were also obtained. Eight and five new prompt γ-ray emissions were observed in the 244Cm(n, γ) and 246Cm(n, γ) reactions, respectively.

[1]  M. Igashira,et al.  Measurements of neutron-capture cross sections of 244Cm and 246Cm at J-PARC/MLF/ANNRI , 2011 .

[2]  J. Katakura,et al.  The 'study on nuclear data by using a high intensity pulsed neutron source for advanced nuclear system' nuclear data project and the characteristics of the neutron beam line for the capture cross section experiments at J-PARC , 2011 .

[3]  M. Igashira,et al.  The ¡°4¨? Ge Spectrometer¡± for Measurements of Neutron Capture Cross Sections bythe TOF Method at the J-PARC/MLF/ANNRI , 2011 .

[4]  M. Igashira,et al.  Study of Neutron Capture Reactions Using the 4?ð Ge Spectrometer , 2011 .

[5]  M. Igashira,et al.  Measurement of energy spectra and spatial distributions of neutron beams provided by the ANNRI beamline for capture cross-section measurements at the J-PARC/MLF , 2011 .

[6]  K. Shibata,et al.  JENDL-4.0: A New Library for Nuclear Science and Engineering , 2011 .

[7]  M. Igashira,et al.  Measurement of Neutron Capture Cross Section Ratios of 244Cm Resonances Using NNRI , 2010 .

[8]  Noboru Watanabe,et al.  First neutron production utilizing J-PARC pulsed spallation neutron source JSNS and neutronic performance demonstrated , 2010 .

[9]  M. Igashira,et al.  A dead-time correction method for multiple gamma-ray detection , 2009, 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC).

[10]  M. Mizumoto,et al.  Development of a 4π germanium spectrometer for nuclear data measurements at J-PARC , 2009, 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC).

[11]  M. Igashira,et al.  Nuclear data study at J-PARC BL04 , 2009 .

[12]  Mihai Anitescu,et al.  Nuclear data sensitivity, uncertainty and target accuracy assessment for future nuclear systems , 2006 .

[13]  Masayuki Igashira,et al.  Development of a Data Acquisition System for a Multiple Gamma‐Ray Detection Method , 2005 .

[14]  N. M. Larson,et al.  Updated Users' Guide for SAMMY Multilevel R-matrix Fits to Neutron Data Using Bayes' Equation , 1998 .

[15]  C. Marsol,et al.  245Cm States Fed by the α-Decay of 249Cf , 1997 .

[16]  I. Ahmad,et al.  Electron capture decay of 245Bk (4.90 d) and 246Bk (1.80 d) , 1976 .

[17]  A. M. Friedman,et al.  (d,p) and (d,t) Studies of the Actinide Elements. II. ^{243}Cm, ^{245}Cm, ^{247}Cm, and ^{249}Cm , 1971 .

[18]  J. H. Gibbons,et al.  Capture-Cross-Section Studies for 30—220-keV Neutrons Using a New Technique , 1967 .

[19]  J. Starner,et al.  Decay of 245Am , 1967 .

[20]  W. Marsden.  I and J , 2012 .

[21]  Tadashi Yoshida,et al.  Analysis of Prediction Accuracy for Actinide Decay Heat of Spent MOX Fuel from Light Water Reactors , 2010 .

[22]  Atsushi Kimura,et al.  Performance of a high speed and high density data acquisition system for multiple gamma-ray detection , 2008, 2008 IEEE Nuclear Science Symposium Conference Record.

[23]  M. Igashira,et al.  Performance of a 4π Ge spectrometer for neutron capture cross section measurements , 2007 .

[24]  J. F. Briesmeister.  MCNP-A General Monte Carlo N-Particle Transport Code , 1993 .

[25]  Richard B. Firestone,et al.  Table of Isotopes , 1978 .

[26]  M. S. Moore,et al.  Analysis of the Fission and Capture Cross Sections of the Curium Isotopes , 1971 .