ENTRY 23748 20220901 2374800000001 SUBENT 23748001 20220901 20230412 2374800100001 BIB 16 80 2374800100002 TITLE Measurements of the neutron capture cross section of 2374800100003 243Am around 23.5 keV 2374800100004 AUTHOR (Y.Kodama,T.Katabuchi,G.Rovira,A.Kimura,S.Nakamura, 2374800100005 S.Endo,N.Iwamoto,O.Iwamoto,J.Hori,Y.Shibahara, 2374800100006 K.Terada,H.Nakano,Y.Sato) 2374800100007 INSTITUTE (2JPNTIT,2JPNJAE,2JPNKTO) 2374800100008 REFERENCE (J,NST,58,1159,2021) 2374800100009 #doi:10.1080/00223131.2021.1943557 2374800100010 REL-REF (I,,K.Kino+,J,NIM/A,736,66,2014) 2374800100011 Energy resolution of the pulsed neutron 2374800100012 (I,23746001,G.Rovira,J,NIM/A,1003,165318,2021) 2374800100013 Experimental setup and filtered neutron spectrum 2374800100014 FACILITY (SYNCY,2JPNJAE) ANNRI(BL04) beam line of MLF at J-PARC 2374800100015 INC-SOURCE (SPALL) Spallation reaction in a mercury target 2374800100016 irradiated with 3-GeV protons (606kW). 2374800100017 The proton beams were supplied at a repetition rate of 2374800100018 25 Hz and in the "double-bunch mode", in which the 2374800100019 pulsed protons consist of two bunches, each with a 2374800100020 width of 100 ns, at intervals of 600 ns. 2374800100021 To improve neutron energy resolution, Fe neutron 2374800100022 filters with thickness of 20 cm were installed. 2374800100023 DETECTOR (NAICR) 330 mm (diam.) and 203 mm in thickness, 90 deg 2374800100024 with respect to the neutron beam line. 2374800100025 Dead time is typically 3 us. 2374800100026 (SCIN) Two plastic scintillator to eliminate events 2374800100027 triggered mainly by cosmic rays: 2374800100028 - 403 (354) mm in outer (inner) diam. and 330 mm in 2374800100029 length for 90deg detector; 2374800100030 - 266 (225) mm in outer (inner) diam. and 254 mm in 2374800100031 length for 125deg detector. 2374800100032 DAQ: CAEN V1720 Digitizer (12bit, 250MHz) 2374800100033 METHOD (FNB,TOF) Neutron TOF experiment with a neutron 2374800100034 filtering system. 2374800100035 SAMPLE An 243Am sample with a mass of 38.14 mg and an 2374800100036 activity of 281.8 MBq was used. The sample was shaped 2374800100037 like a disk with 10 mm in diameter and 0.5 mm in 2374800100038 thickness, made of AmO2 powder mixed with binder 2374800100039 material of Y2O3 (39 mg) . The sample was sealed in 2374800100040 an Al container. 2374800100041 A dummy sample, an Al container with the identical 2374800100042 dimensions to the 243Am sample, including only Y2O3, 2374800100043 was also used for background measurements. 2374800100044 A carbon sample with a diameter of 10 mm and a 2374800100045 thickness of 0.5 mm was used as neutron scatterer 2374800100046 to subtract background. 2374800100047 A gold sample with a 10 mm diameter, 1 mm thickness 2374800100048 was used for normalization. 2374800100049 A boron sample with a diameter of 10 mm and a 2374800100050 thickness of 0.5 mm was used for neutron spectrum 2374800100051 measurement. 2374800100052 INC-SPECT Relative neutron TOF spectrum was measured by 2374800100053 detecting the 478-keV gamma rays from 2374800100054 10B(n,alpha gamma)7Li reactions. 2374800100055 Energy distribution of the filtered neutron spectrum 2374800100056 was written in NIM-A1003(2021)165318. 2374800100057 ANALYSIS The pulse height weighting technique (PHWT) was 2374800100058 applied to derive the neutron capture yield. 2374800100059 Measurements with the carbon sample, 2374800100060 "Dummy replica sample", and "Blank (no sample) " were 2374800100061 used for back ground estimation. 2374800100062 The neutron capture cross section of 243Am was 2374800100063 determined relative to the capture cross section of 2374800100064 197Au. 2374800100065 CORRECTION Dead Time Correction was applied with the extended 2374800100066 dead-time model. 2374800100067 Correction factors for self shielding and multiple 2374800100068 scattering were deduced using the PHITS. 2374800100069 Contributions of discriminated gamma-rays to the 2374800100070 capture yields were estimated from theoretical 2374800100071 calculation using the nuclear reaction model code 2374800100072 CCONE and detector response functions obtained 2374800100073 by PHITS code. 2374800100074 Contributions from the impurities to the capture 2374800100075 yield were calculated using the evaluated cross 2374800100076 sections of the impurities in JENDL-4.0. 2374800100077 The influence of the fission events was very small 2374800100078 and neglected. 2374800100079 MONITOR (79-AU-197(N,G)79-AU-198,,SIG) 2374800100080 MONIT-REF (,,3,JENDL-4.0,,2010) 2374800100081 HISTORY (20220901C) Compiled by A. Kimura. 2374800100082 ENDBIB 80 0 2374800100083 NOCOMMON 0 0 2374800100084 ENDSUBENT 83 0 2374800199999 SUBENT 23748002 20220901 20230412 2374800200001 BIB 4 32 2374800200002 REACTION (95-AM-243(N,G)95-AM-244,,SIG) 2374800200003 MISC-COL (MISC) Median energy of the incident neutrons. 2374800200004 See Figs.20 of NIM-A1003(2021)165318 2374800200005 ERR-ANALYS (ERR-T) Total uncertainty. 2374800200006 (MONIT-ERR) Systematic uncertainty related to 2374800200007 standard 197Au cross section. 2374800200008 (ERR-1) Statistical uncertainty for the 243Am sample 2374800200009 measurement. 2374800200010 (ERR-2) Statistical uncertainty for the Au sample 2374800200011 measurement. 2374800200012 (ERR-3) Systematic uncertainty related to Beam power 2374800200013 fluctuation. 2374800200014 (ERR-4) Systematic uncertainty related to sample mass. 2374800200015 (ERR-5) Systematic uncertainty related to the 2374800200016 weighting function. 2374800200017 (ERR-6) Systematic uncertainty related to the self 2374800200018 shielding and multiple scattering correction 2374800200019 for the 243Am sample. 2374800200020 (ERR-7) Systematic uncertainty related to the self 2374800200021 shielding and multiple scattering correction 2374800200022 for the Au sample. 2374800200023 (ERR-8) Systematic uncertainty related to the 2374800200024 corrections for gamma-rays below threshold 2374800200025 for the 243Am sample. 2374800200026 (ERR-9) Systematic uncertainty related to the 2374800200027 corrections for gamma-rays below threshold 2374800200028 for the Au sample. 2374800200029 (ERR-10) Systematic uncertainty related to the 2374800200030 corrections for impurities. 2374800200031 STATUS (TABLE) Fig. 4 and Table 1 in REFERENCE. 2374800200032 Data were obtained from AUTHOR 2374800200033 (SUPPL,23746003) Neutron spectrum 2374800200034 ENDBIB 32 0 2374800200035 COMMON 12 6 2374800200036 MONIT MONIT-ERR ERR-1 ERR-2 ERR-3 ERR-4 2374800200037 ERR-5 ERR-6 ERR-7 ERR-8 ERR-9 ERR-10 2374800200038 B PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2374800200039 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2374800200040 0.64 3.0 3.1 2.5 0.5 0.22374800200041 1.0 0. 0.8 1.4 1.2 0.32374800200042 ENDCOMMON 6 0 2374800200043 DATA 5 1 2374800200044 EN-MIN EN-MAX MISC DATA ERR-T 2374800200045 KEV KEV KEV B B 2374800200046 22.0 24.8 23.5 2.52 0.14 2374800200047 ENDDATA 3 0 2374800200048 ENDSUBENT 47 0 2374800299999 ENDENTRY 2 0 2374899999999