ENTRY 23538 20200211 22862353800000001 SUBENT 23538001 20200211 22862353800100001 BIB 18 200 2353800100002 TITLE Measurement of the 13C(n,gamma) thermal cross section 2353800100003 via neutron irradiation and AMS 2353800100004 AUTHOR (T.Wright, S.Bennett, S.Heinitz, U.Koster, R.Mills, 2353800100005 T.Soldner, P.Steier, A.Wallner, T.Wieninger) 2353800100006 INSTITUTE (2UK MAN,2SWTPSI,2FR ILL,2UK NPL,2AUSVIE,3AULCBR) 2353800100007 REFERENCE (J,EPJ/A,55,200,2019) 2353800100008 #doi:10.1140/epja/i2019-12893-0 2353800100009 FACILITY (REAC,2FR ILL) PF1b cold-neutron beam facility 2353800100010 INC-SPECT Thermal equivalent capture flux of 2x10**10 n/cm2/s 2353800100011 with a mean energy of 4 meV. 2353800100012 SAMPLE (6-C-13,ENR=0.995) 2353800100013 Set I of samples with 0.4 cm deam. sealed in 3.5 cm 2353800100014 length quartz ampoules prepared by heating with a blow 2353800100015 torch to red heat: 2353800100016 Sample: 13C/1a 13C/1a 13C/1a 13C/1a 13C/1a 2353800100017 Mass (mg): 9.1 46.1 99.1 33.5 74.7 2353800100018 Set II of samples prepared by baking at 900 degree C 2353800100019 for two hours: 2353800100020 Sample: 13C/6b 13C/7b 13C/8b 13C/9b 2353800100021 Mass (mg): 20.0 32.2 13.2 20.0 2353800100022 Samples with natural isotopic composition: 2353800100023 Sample: natC/10b natC/11b natC/12b 2353800100024 Mass (mg): 23.4 201.5 36.0 2353800100025 METHOD (ACTIV) 2353800100026 Sample Irradiation time (min) 2353800100027 13C/1a 600 2353800100028 13C/2a 600 2353800100029 13C/3a 600 2353800100030 13C/4a 600 2353800100031 13C/6b 571 2353800100032 13C/7b 571 2353800100033 natC/10b 571 2353800100034 natC/11b 571 2353800100035 natC/12b 13833 2353800100036 (AMS) 2353800100037 DECAY-DATA (6-C-14,5730.YR) T1/2 = 5730 +- 40 years 2353800100038 REL-REF (R,,F.Ajzenberg-Selove,J,NP/A,523,1,1991) 2353800100039 C-14 half-life 2353800100040 ANALYSIS 1/v dependence on the neutron energy was assumed with 2353800100041 a Westcott factor of 1. 2353800100042 Only samples 6b and 7b are considered for the cross 2353800100043 section calculation and the mean 14C/13C ratio of 2353800100044 (1.159 +- 0.021)x10**12 is taken from the AMS 2353800100045 measurements. This is then divided by the product of 2353800100046 the irradiation time (34260 s) and the measured flux 2353800100047 for experiment two ((2.20 +- 0.09)x10**10 n/cm2/s) to 2353800100048 give a final 14C production cross section of 2353800100049 1.538 +- 0.069mb. This value is then reduced by 2353800100050 (0.93 +- 0.39)% to account for the estimated 2353800100051 14C production from 14N(n,p) to give the final result. 2353800100052 Sample 14C/13C(x10**-12) 2353800100053 13C/1a 1.173 +- 0.021 2353800100054 13C/2a 1.172 +- 0.013 2353800100055 13C/3a 1.199 +- 0.022 2353800100056 13C/4a 0.622 +- 0.010 2353800100057 13C/5a 0.0011 +- 0.0003 2353800100058 13C/6b 1.154 +- 0.025 2353800100059 13C/7b 1.166 +- 0.014 2353800100060 13C/8b 0.0013 +- 0.0007 2353800100061 13C/9b 0.0017 +- 0.0008 2353800100062 natC/10b 2.41 +- 0.14 2353800100063 natC/11b 1.86 +- 0.15 2353800100064 natC/12b 5150 2353800100065 IAEA C3 139.9 +- 1.4 2353800100066 IAEA C6 164.5 +- 1.3 2353800100067 CTW2 135.5 +- 4.4 2353800100068 MONITOR ((MONIT1)29-CU-63(N,G)29-CU-64,,SIG) 2353800100069 ((MONIT2)40-ZR-94(N,G)40-ZR-95,,SIG) 2353800100070 ((MONIT3)40-ZR-96(N,G)40-ZR-97,,SIG) 2353800100071 Measured neutron flux from the corresponding flux 2353800100072 monitor foils: 2353800100073 Irradiation "a" (2016) 2353800100074 Activated isotope Foil No. Flux (x10**10 n/cm2/s) 2353800100075 63Cu 1 2.09 +- 0.106 2353800100076 63Cu 2 2.06 +- 0.114 2353800100077 63Cu 3 2.05 +- 0.121 2353800100078 63Cu 4 2.35 +- 0.129 2353800100079 63Cu 5 2.33 +- 0.126 2353800100080 63Cu 6 2.31 +- 0.144 2353800100081 63Cu 7 2.50 +- 0.149 2353800100082 63Cu 8 2.05 +- 0.140 2353800100083 94Zr 1 2.31 +- 0.130 2353800100084 94Zr 2 1.73 +- 0.108 2353800100085 94Zr 3 2.15 +- 0.151 2353800100086 94Zr 4 1.90 +- 0.134 2353800100087 94Zr 5 2.27 +- 0.148 2353800100088 94Zr 6 2.16 +- 0.128 2353800100089 94Zr 7 2.10 +- 0.127 2353800100090 94Zr 8 1.74 +- 0.115 2353800100091 94Zr 9 1.88 +- 0.126 2353800100092 94Zr 10 2.06 +- 0.124 2353800100093 96Zr 1 2.29 +- 0.0928 2353800100094 96Zr 2 2.03 +- 0.0871 2353800100095 96Zr 3 2.10 +- 0.103 2353800100096 96Zr 4 2.13 +- 0.0987 2353800100097 96Zr 5 2.05 +- 0.0977 2353800100098 96Zr 6 2.00 +- 0.0863 2353800100099 96Zr 7 1.99 +- 0.0888 2353800100100 96Zr 8 1.88 +- 0.0843 2353800100101 96Zr 9 2.09 +- 0.0947 2353800100102 96Zr 10 2.05 +- 0.0889 2353800100103 All foils/a 2.09 +- 0.15 2353800100104 Irradiation "b" (2018) 2353800100105 Activated isotope Foil No. Flux (x10**10 n/cm2/s) 2353800100106 63Cu 1 2.25 +- 0.0739 2353800100107 63Cu 2 2.30 +- 0.0533 2353800100108 94Zr 1 2.26 +- 0.0941 2353800100109 94Zr 2 2.14 +- 0.0884 2353800100110 94Zr 3 2.08 +- 0.0883 2353800100111 94Zr 4 2.07 +- 0.0887 2353800100112 94Zr 5 2.28 +- 0.0963 2353800100113 94Zr 6 2.21 +- 0.100 2353800100114 96Zr 1 2.28 +- 0.0771 2353800100115 96Zr 2 2.18 +- 0.0739 2353800100116 96Zr 3 2.16 +- 0.0785 2353800100117 96Zr 4 2.16 +- 0.0795 2353800100118 96Zr 5 2.39 +- 0.0873 2353800100119 96Zr 6 2.10 +- 0.0847 2353800100120 All foils/b 2.20 +- 0.09 2353800100121 MONIT-REF ((MONIT1),S.F.Mughabghab,B,NEUT.RES,,,2018) 2353800100122 ((MONIT2),S.F.Mughabghab,B,NEUT.RES,,,2018) 2353800100123 ((MONIT3),S.F.Mughabghab,B,NEUT.RES,,,2018) 2353800100124 DECAY-MON (29-CU-64,12.701HR,AR,511.,0.352,DG,1345.9,0.00475) 2353800100125 (40-ZR-95,64.032D,DG,724.2,0.437,DG,756.7,0.553) 2353800100126 (40-ZR-97,16.749HR,DG,743.,0.928) 2353800100127 ADD-RES 14C production cross sections for each carbon sample: 2353800100128 (Numerical data for the results plotted on fig.2 2353800100129 provided by authors) 2353800100130 Cross section Cross section Cross section 2353800100131 (mb) (mb) (mb) 2353800100132 sample 1a 2353800100133 cathode 1 cathode 2 cathode 3 2353800100134 1 1.535 +- 0.114 1.547 +- 0.114 1.577 +- 0.118 2353800100135 2 1.515 +- 0.112 1.552 +- 0.115 1.577 +- 0.118 2353800100136 3 1.530 +- 0.113 1.583 +- 0.117 1.608 +- 0.120 2353800100137 4 1.506 +- 0.112 1.577 +- 0.117 1.605 +- 0.120 2353800100138 5 1.527 +- 0.113 1.573 +- 0.116 1.585 +- 0.118 2353800100139 6 1.540 +- 0.114 1.564 +- 0.116 1.566 +- 0.117 2353800100140 7 1.532 +- 0.113 1.557 +- 0.115 1.586 +- 0.118 2353800100141 8 1.542 +- 0.114 1.571 +- 0.116 1.573 +- 0.117 2353800100142 9 1.533 +- 0.113 1.582 +- 0.117 2353800100143 sample 2a 2353800100144 1 1.568 +- 0.116 1.582 +- 0.117 1.532 +- 0.115 2353800100145 2 1.552 +- 0.115 1.586 +- 0.117 1.538 +- 0.116 2353800100146 3 1.549 +- 0.114 1.592 +- 0.118 1.531 +- 0.115 2353800100147 4 1.569 +- 0.116 1.570 +- 0.116 1.529 +- 0.115 2353800100148 5 1.568 +- 0.116 1.561 +- 0.116 1.516 +- 0.113 2353800100149 6 1.570 +- 0.116 1.564 +- 0.116 1.561 +- 0.116 2353800100150 7 1.579 +- 0.117 1.565 +- 0.116 1.544 +- 0.115 2353800100151 8 1.568 +- 0.116 1.560 +- 0.116 1.560 +- 0.116 2353800100152 9 1.554 +- 0.115 1.571 +- 0.116 1.562 +- 0.116 2353800100153 sample 3a 2353800100154 1 1.536 +- 0.114 1.589 +- 0.118 1.595 +- 0.119 2353800100155 2 1.566 +- 0.116 1.593 +- 0.118 1.546 +- 0.116 2353800100156 3 1.555 +- 0.115 1.581 +- 0.117 1.539 +- 0.115 2353800100157 4 1.615 +- 0.119 1.594 +- 0.118 1.552 +- 0.115 2353800100158 5 1.608 +- 0.119 1.601 +- 0.119 1.582 +- 0.117 2353800100159 6 1.610 +- 0.119 1.616 +- 0.120 1.581 +- 0.117 2353800100160 7 1.626 +- 0.120 1.602 +- 0.119 1.592 +- 0.118 2353800100161 8 1.632 +- 0.121 1.601 +- 0.119 1.641 +- 0.122 2353800100162 9 1.643 +- 0.122 1.612 +- 0.119 1.632 +- 0.121 2353800100163 sample 4a 2353800100164 1 1.583 +- 0.118 1.608 +- 0.121 1.523 +- 0.115 2353800100165 2 1.564 +- 0.116 1.577 +- 0.119 1.491 +- 0.113 2353800100166 3 1.559 +- 0.116 1.551 +- 0.116 1.591 +- 0.120 2353800100167 4 1.549 +- 0.115 1.578 +- 0.118 1.540 +- 0.115 2353800100168 5 1.588 +- 0.118 1.578 +- 0.117 1.541 +- 0.115 2353800100169 6 1.597 +- 0.118 1.581 +- 0.117 1.544 +- 0.115 2353800100170 7 1.598 +- 0.119 1.584 +- 0.118 1.555 +- 0.116 2353800100171 8 1.600 +- 0.119 1.580 +- 0.117 1.545 +- 0.115 2353800100172 9 1.587 +- 0.118 1.580 +- 0.117 1.541 +- 0.116 2353800100173 sample 6b 2353800100174 1 1.436 +- 0.065 1.581 +- 0.070 1.518 +- 0.067 2353800100175 2 1.539 +- 0.068 1.548 +- 0.069 1.520 +- 0.069 2353800100176 3 1.551 +- 0.070 1.535 +- 0.069 1.491 +- 0.067 2353800100177 4 1.508 +- 0.067 1.538 +- 0.069 1.520 +- 0.068 2353800100178 5 1.552 +- 0.069 1.547 +- 0.069 1.521 +- 0.068 2353800100179 sample 7b 2353800100180 1 1.506 +- 0.066 1.517 +- 0.071 1.528 +- 0.068 2353800100181 2 1.537 +- 0.068 1.537 +- 0.070 1.549 +- 0.070 2353800100182 3 1.554 +- 0.069 1.530 +- 0.069 1.560 +- 0.073 2353800100183 4 1.577 +- 0.070 1.548 +- 0.070 1.545 +- 0.069 2353800100184 5 1.556 +- 0.069 1.568 +- 0.074 1.541 +- 0.069 2353800100185 ERR-ANALYS (ERR-T) The total uncertainty (one standard 2353800100186 deviation) determined from: 2353800100187 (ERR-1) AMS isotopic ratio taken as one standard 2353800100188 deviation of the isotopic ratios of all sputter 2353800100189 samples associated with a given sample. 2353800100190 (ERR-2) Uncertainty of the flux measurement 2353800100191 determined from: 2353800100192 - Statistical uncertainties on the activity 2353800100193 measurements 6%, 5% and 4% for 64Cu, 95Zr and 97Zr for 2353800100194 experiment "a" and respectively 3%, 3% and 2% for 2353800100195 experiment "b" 2353800100196 - Systematic uncertainties from the neutron activation 2353800100197 cross sections, decay constants and branching ratios 2353800100198 0.4%, 3.3% and 3.0% for 64Cu, 95Zr and 97Zr 2353800100199 respectively for both experiments. 2353800100200 STATUS (APRVD) Proof-read by T.Wright (2020-02-20) 2353800100201 HISTORY (20200211C) VS 2353800100202 ENDBIB 200 0 2353800100203 COMMON 6 3 2353800100204 MONIT1 MONIT1-ERR MONIT2 MONIT2-ERR MONIT3 MONIT3-ERR 2353800100205 B B B B B B 2353800100206 4.50 0.02 0.0494 0.0017 0.0229 0.00102353800100207 ENDCOMMON 3 0 2353800100208 ENDSUBENT 207 0 2353800199999 SUBENT 23538002 20200211 22862353800200001 BIB 3 4 2353800200002 REACTION (6-C-13(N,G)6-C-14,,SIG) 2353800200003 MISC-COL (MISC) cross section not corrected for 14N(n,p)13C 2353800200004 contribution 2353800200005 STATUS (TABLE) Text on page 6 of Eur. Phys. J. A 55(2019) 200 2353800200006 ENDBIB 4 0 2353800200007 NOCOMMON 0 0 2353800200008 DATA 7 1 2353800200009 EN DATA ERR-T ERR-1 ERR-2 MISC 2353800200010 MISC-ERR 2353800200011 EV MB MB PER-CENT PER-CENT MB 2353800200012 MB 2353800200013 0.0253 1.52 0.07 1.8 4.1 1.538 2353800200014 0.069 2353800200015 ENDDATA 6 0 2353800200016 ENDSUBENT 15 0 2353800299999 ENDENTRY 2 0 2353899999999