ENTRY 23602 20201016 22952360200000001 SUBENT 23602001 20201016 22952360200100001 BIB 16 60 2360200100002 TITLE Measurements of thermal-neutron capture cross-section 2360200100003 of Cesium-135 by applying mass spectrometry 2360200100004 AUTHOR (S.Nakamura,Y.Shibahara,A.Kimura,O.Iwamoto,A.Uehara, 2360200100005 T.Fujii) 2360200100006 INSTITUTE (2JPNJAE,2JPNKTO,2JPNIRS,2JPNOSA) 2360200100007 REFERENCE (J,NST,57,388,2020) 2360200100008 #doi:10.1080/00223131.2019.1691077 2360200100009 FACILITY (REAC,2JPNKTO) 2360200100010 INC-SOURCE (REAC) Hydraulic Conveyer in the Kyoto University 2360200100011 Research Reactor(KUR) . KUR was operated at the 2360200100012 thermal power of 5 MW. 2360200100013 SAMPLE Cs-137 standard solution, Code# CS005, which was 2360200100014 supplied by JRIA was used for the samples. Cs-135 was 2360200100015 included as an impurity in the Cs-137 standard 2360200100016 solution. Two Cs-137 standard solutions equivalent to 2360200100017 about 200 Bq were prepared. The isotope ratios of 2360200100018 Cs-135 to Cs-137 were determined with TIMS. 2360200100019 Bare target: Cs-135/Cs-137 = 0.8970 +- 0.00024 2360200100020 Gd Shield: Cs-135/Cs-137 = 0.8990 +- 0.00014 2360200100021 METHOD (ACTIV,GSPEC) Cadmium-difference method. To set 2360200100022 0.133 eV as cut-off energy, Gd foils with thickness 2360200100023 of 25 um was used as neutron filter. Wires of Au/Al 2360200100024 alloy and Co/Al alloy were used to monitor neutron 2360200100025 fluxes. A set of the samples with and without the Gd 2360200100026 filters were used for the experiments. 2360200100027 Irradiations for the bare and Gd filtered targets 2360200100028 were performed for 3 and 6 h, respectively. 2360200100029 DETECTOR (HPGE) High purity germanium detector, relative 2360200100030 efficiency of 70% and 1.9 keV FWHM at the 1.33 MeV. 2360200100031 ANALYSIS The activities of Cs-137, Cs-136 and monitor wires 2360200100032 were measured by gamma-ray spectroscopy. Neutron flux 2360200100033 was deduced from the activities of the wires. (tables 2360200100034 2 and 3 in the REFERENCE) Deduced neutron flux: (e+14 2360200100035 n/cm2/sec) Thermal neutron Epi-thermal neutron Bare 2360200100036 target: 1.07 +-0.03 0.313+-0.021 Gd Shield: 2360200100037 0.155+-0.006 0.426+-0.012 The main contribution of 2360200100038 the uncertainties came from uncertainties due to 2360200100039 abundance of Co and Au in the wires and the detection 2360200100040 effeciency of the Ge detector. On the basis of 2360200100041 Westcott's convention, the cross section was derived 2360200100042 from the activity ratio of Cs-136 to Cs-137, the 2360200100043 half-lives of Cs-136 and Cs-137, the isotopic ratio 2360200100044 of Cs-135 to Cs-137 in the sample, and the neutron 2360200100045 fluxes. 2360200100046 CORRECTION The peak detection efficiencies were determined with 2360200100047 a set of calibrated mixed sources: Cd-109, Co-57, 2360200100048 Ce-139, Sn-113, Cs-137, Y-88, and Co-60. 2360200100049 DECAY-DATA (55-CS-136-G,13.16D,DG,818.5,0.997) 2360200100050 (55-CS-137,30.05YR,DG,661.6,0.8499) 2360200100051 (27-CO-60-G,5.2711YR,DG,1332.5,0.999826) 2360200100052 (79-AU-198-G,2.6943D,DG,441.8,0.9562) 2360200100053 ASSUMED Values assumed to deduce the thermal and epi-thermal 2360200100054 neutron fluxes. 2360200100055 (ASSUM1,27-CO-59(N,G)27-CO-60,,SIG) Thermal C.S. 2360200100056 (ASSUM2,79-AU-197(N,G)79-AU-198,,SIG) Thermal C.S. 2360200100057 REL-REF (R,,S.F.Mughabghab,B,NEUT.RES,,2-1,2006) 2360200100058 59Co and 197Au thermal cross sections given 2360200100059 HISTORY (20201016C) Atsushi Kimura 2360200100060 ERR-ANALYS (ASSUM1-ERR) Unc. of Co-59 thermal C.S. 2360200100061 (ASSUM2-ERR) Unc. of Au-197 thermal C.S. 2360200100062 ENDBIB 60 0 2360200100063 COMMON 4 3 2360200100064 ASSUM1 ASSUM1-ERR ASSUM2 ASSUM2-ERR 2360200100065 B B B B 2360200100066 37.18 0.06 98.65 0.09 2360200100067 ENDCOMMON 3 0 2360200100068 ENDSUBENT 67 0 2360200199999 SUBENT 23602002 20201016 22952360200200001 BIB 3 13 2360200200002 REACTION (55-CS-135(N,G)55-CS-136,,SIG) 2360200200003 STATUS (TABLE) From Tables 8, 10 of the REFERENCE 2360200200004 ERR-ANALYS (ERR-T) Total Unc. 2360200200005 (ERR-1) Unc. due to Half-life of Cs-137 2360200200006 (ERR-2) Statistical unc. of 662 keV g-rays from Cs-137 2360200200007 (ERR-3) Unc. due to emission probability of 662 keV 2360200200008 (ERR-4) Unc. due to detection efficiency for 662 keV 2360200200009 (ERR-5) Unc. due to isotopic ratio Cs-135/Cs-137 2360200200010 (ERR-6) Unc. due to Half-life of Cs-136 2360200200011 (ERR-7) Statistical unc. of 818 keV g-rays from Cs-136 2360200200012 (ERR-8) Unc. due to emission probability of 818 keV 2360200200013 (ERR-9) Unc. due to detection efficiency for 818 keV 2360200200014 (ERR-10) Unc. due to Irradiation time 2360200200015 ENDBIB 13 0 2360200200016 COMMON 10 6 2360200200017 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2360200200018 ERR-7 ERR-8 ERR-9 ERR-10 2360200200019 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2360200200020 PER-CENT PER-CENT PER-CENT PER-CENT 2360200200021 0.27 0.04 0.24 0.24 0.27 0.122360200200022 0.76 0.00 0.19 0.83 2360200200023 ENDCOMMON 6 0 2360200200024 DATA 3 1 2360200200025 EN DATA ERR-T 2360200200026 EV B B 2360200200027 0.0253 8.57 0.25 2360200200028 ENDDATA 3 0 2360200200029 ENDSUBENT 28 0 2360200299999 SUBENT 23602003 20201016 22952360200300001 BIB 3 13 2360200300002 REACTION (55-CS-135(N,G)55-CS-136,,RI) 2360200300003 STATUS (TABLE) From Tables 8, 10 of the REFERENCE 2360200300004 ERR-ANALYS (ERR-T) Total Unc. 2360200300005 (ERR-1) Unc. due to Half-life of Cs-137 2360200300006 (ERR-2) Statistical unc. of 662 keV g-rays from Cs-137 2360200300007 (ERR-3) Unc. due to emission probability of 662 keV 2360200300008 (ERR-4) Unc. due to detection efficiency for 662 keV 2360200300009 (ERR-5) Unc. due to isotopic ratio Cs-135/Cs-137 2360200300010 (ERR-6) Unc. due to Half-life of Cs-136 2360200300011 (ERR-7) Statistical unc. of 818 keV g-rays from Cs-136 2360200300012 (ERR-8) Unc. due to emission probability of 818 keV 2360200300013 (ERR-9) Unc. due to detection efficiency for 818 keV 2360200300014 (ERR-10) Unc. due to Irradiation time 2360200300015 ENDBIB 13 0 2360200300016 COMMON 10 6 2360200300017 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2360200300018 ERR-7 ERR-8 ERR-9 ERR-10 2360200300019 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2360200300020 PER-CENT PER-CENT PER-CENT PER-CENT 2360200300021 0.27 0.04 0.24 0.24 0.27 0.122360200300022 0.76 0.00 0.19 0.83 2360200300023 ENDCOMMON 6 0 2360200300024 DATA 3 1 2360200300025 EN-MIN DATA ERR-T 2360200300026 EV B B 2360200300027 0.133 45.3 3.2 2360200300028 ENDDATA 3 0 2360200300029 ENDSUBENT 28 0 2360200399999 ENDENTRY 3 0 2360299999999