ENTRY 23742 20210831 23022374200000001 SUBENT 23742001 20210831 23022374200100001 BIB 16 82 2374200100002 TITLE Thermal-neutron capture cross-section measurement of 2374200100003 Tantalum-181 using graphite thermal column at KUR 2374200100004 AUTHOR (S.Nakamura,Y.Shibahara,S.Endo,A.Kimura) 2374200100005 INSTITUTE (2JPNJAE,2JPNKTO) 2374200100006 REFERENCE (J,NST,58,1061,2021) 2374200100007 #doi:10.1080/00223131.2021.1908187 2374200100008 FACILITY (REAC,2JPNKTO) 2374200100009 Kyoto University Research Reactor (KUR). 2374200100010 INC-SOURCE (REAC)The graphite thermal column (TC-Pn) in KUR. 2374200100011 The nominal neutron flux intensity of TC-Pn is 2374200100012 5.86E+10 (n/cm2/sec) at 1 MW power operation. 2374200100013 The AUTHORs confirmed that the TC-Pn was extremely 2374200100014 thermalized on the basis of Westcott's convention 2374200100015 using neutron flux monitors: Au-197, Co-59, Sc-45, 2374200100016 Cu-63, and Mo-98. (See Fig. 8 in the REFERENCE.) 2374200100017 SAMPLE (73-TA-181,NAT=0.99988) 2374200100018 Sample: Ta Foil 0.006 mmt 1.129+-0.001 mg 2374200100019 Monitor: Au/Al Alloy wire 4.451+-0.001 mg 2374200100020 Co Foil 0.005 mmt 0.632+-0.001 mg 2374200100021 Sc Foil 0.025 mmt 0.405+-0.001 mg 2374200100022 Cu Foil 0.025 mmt 3.587+-0.001 mg 2374200100023 Mo Foil 0.025 mmt 1.129+-0.001 mg 2374200100024 The sample and the monitors were irradiated 2374200100025 in the TC-Pn for 30 minutes under 1-MW power operation.2374200100026 DETECTOR (HPGE) High purity germanium detector, relative 2374200100027 efficiency of 25%. 2374200100028 The gamma-ray peak efficiencies of the Ge detector were2374200100029 measured using a mixed source AM-8140 (Eckert & Ziegler2374200100030 Nuclitec GmbH, Germany) : Am-241, Cd-109, Co-57, 2374200100031 Ce-139, Hg-203, Sn-113, Cs-137, Co-60 and Y-88. 2374200100032 METHOD (ACTIV,GSPEC) Based on Westcott's convention method. 2374200100033 Because the neutron flux in the TC-Pn is well 2374200100034 thermalized (See Fig.8 in the REFERENCE) , epithermal 2374200100035 component in Westcott's convention method was 2374200100036 negligibly small. 2374200100037 ANALYSIS The reaction rate of the Ta sample was obtained from 2374200100038 the yield of each gamma ray emitted from the 2374200100039 irradiated Ta sample. 2374200100040 The weighted average of the reaction rates was derived 2374200100041 using 1121-, 1189-, 1221- and 1231-keV gamma rays. 2374200100042 Thermal capture cross section and g-factor were taken 2374200100043 from the REL-REF. 2374200100044 The thermal-neutron flux was derived as 2374200100045 (5.688+-0.091)E+10(n/cm2/sec) using the reaction 2374200100046 rates and the thermal cross section of the monitors. 2374200100047 The cross section of Ta-181 was derived from the 2374200100048 reaction rate of the Ta sample and the 2374200100049 thermal-neutron flux component. 2374200100050 CORRECTION Self-shielding coefficients for thermal neutrons were 2374200100051 calculated from neutron capture cross-sections and 2374200100052 area densities of the sample and the monitors. 2374200100053 The coincidence summing effect was estimated from 2374200100054 the peak-to-total ratios and the peak efficiencies. 2374200100055 DECAY-DATA (79-AU-198-G,2.6943D,DG,411.80,0.9562) 2374200100056 (27-CO-60-G,5.2711YR,DG,1173.24,0.99826, 2374200100057 DG,1332.50,0.9985) 2374200100058 (21-SC-46-G,83.79D,DG,889.28,0.99984, 2374200100059 DG,1120.55,0.99987) 2374200100060 (29-CU-64,12.700HR,DG,1345.84,0.00473) 2374200100061 (42-MO-99,2.7479D,DG,181.06,0.0599, 2374200100062 DG,366.42,0.0119, 2374200100063 DG,739.50,0.1213, 2374200100064 DG,777.92,0.0426) 2374200100065 (73-TA-182-G,114.43D,DG,1121.30,0.349, 2374200100066 DG,1189.05,0.162, 2374200100067 DG,1221.41,0.270, 2374200100068 DG,1231.02,0.114) 2374200100069 ASSUMED Thermal capture dross section of the monitors were 2374200100070 assumed to deduce the thermal neutron flux. 2374200100071 (ASSUM1,79-AU-197(N,G)79-AU-198,,SIG) 2374200100072 (ASSUM2,27-CO-59(N,G)27-CO-60,,SIG) 2374200100073 (ASSUM3,21-SC-45(N,G)21-SC-46,,SIG) 2374200100074 (ASSUM4,29-CU-63(N,G)29-CU-64,,SIG) 2374200100075 (ASSUM5,42-MO-98(N,G)42-MO-99,,SIG) 2374200100076 ERR-ANALYS (ASSUM1-ERR) Uncertainty of Au-197 thermal C.S. 2374200100077 (ASSUM2-ERR) Uncertainty of Co-59 thermal C.S. 2374200100078 (ASSUM3-ERR) Uncertainty of Sc-45 thermal C.S. 2374200100079 (ASSUM4-ERR) Uncertainty of Cu-63 thermal C.S. 2374200100080 (ASSUM5-ERR) Uncertainty of Mo-98 thermal C.S. 2374200100081 REL-REF (R,,S.F.Mughabghab,B,NEUT.RES,,,2018) Thermal 2374200100082 capture cross section and g-factor were given. 2374200100083 HISTORY (20210831C) Atsushi Kimura 2374200100084 ENDBIB 82 0 2374200100085 COMMON 10 6 2374200100086 ASSUM1 ASSUM1-ERR ASSUM2 ASSUM2-ERR ASSUM3 ASSUM3-ERR 2374200100087 ASSUM4 ASSUM4-ERR ASSUM5 ASSUM5-ERR 2374200100088 B B B B B B 2374200100089 B B B B 2374200100090 98.65 0.09 37.18 0.06 27.2 0.022374200100091 4.50 0.02 0.130 0.006 2374200100092 ENDCOMMON 6 0 2374200100093 ENDSUBENT 92 0 2374200199999 SUBENT 23742002 20210831 23022374200200001 BIB 3 19 2374200200002 REACTION (73-TA-181(N,G)73-TA-182,,SIG) 2374200200003 ERR-ANALYS (ERR-T) Total uncertainty. 2374200200004 (ERR-S) Statistical uncertainty. 2374200200005 (1170+-0.006)E-12 (event/s) 2374200200006 (ERR-1) Uncertainty due to gamma-ray emission 2374200200007 probability and fitting at the gamma-ray 2374200200008 spectroscopy. (1170+-0.021)E-12 (event/s) 2374200200009 (ERR-2) Uncertainty due to half life of Ta-182. 2374200200010 114.43+-0.03 (days) 2374200200011 (ERR-3) Uncertainty due to relative gamma-ray 2374200200012 efficiency of the Ge-detector. 2374200200013 (ERR-4) Uncertainty due to sample weight. 2374200200014 1.129+-0.001 (mg) 2374200200015 (ERR-5) Uncertainty due to irradiation time. 2374200200016 1800+-1 (sec) 2374200200017 (ERR-6) Uncertainty due to the thermal neutron flux. 2374200200018 (5.688+-0.031)E+10(n/cm2/sec) 2374200200019 STATUS (TABLE) Tables 5+6+8 of J.Nucl.Sci.Technol.58(2021)10612374200200020 Data were provided by AUTHOR. 2374200200021 ENDBIB 19 0 2374200200022 COMMON 7 6 2374200200023 ERR-S ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 2374200200024 ERR-6 2374200200025 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2374200200026 PER-CENT 2374200200027 0.51 1.79 0.03 0.16 0.09 0.062374200200028 0.55 2374200200029 ENDCOMMON 6 0 2374200200030 DATA 3 1 2374200200031 EN DATA ERR-T 2374200200032 EV B B 2374200200033 0.0253 20.5 0.4 2374200200034 ENDDATA 3 0 2374200200035 ENDSUBENT 34 0 2374200299999 ENDENTRY 2 0 2374299999999