ENTRY 32835 20230917 3283500000001 SUBENT 32835001 20230917 20240316 3283500100001 BIB 12 31 3283500100002 TITLE Measurement of the thermal neutron absorption cross 3283500100003 section of graphite 3283500100004 AUTHOR (Chen Ying,Gou Cheng,Rong Chaofan,Jiang Songsheng, 3283500100005 Wang Huici,Zhu Shengyun,Hu Xuanwen,Luo Dexing) 3283500100006 INSTITUTE (3CPRAEP) 3283500100007 REFERENCE (J,CST,10,146,1976) 3283500100008 FACILITY (CYCLO,3CPRAEP) 1.2 m 3283500100009 INC-SOURCE (P-LI7) 4.5 MeV proton beam with 50 - 180 Hz, pulse 3283500100010 width 30 - 200 ms, 0.2 - 1.0 mA, is induced on 0.5 - 3283500100011 0.8 mm metal Li. 3283500100012 SAMPLE Graphite prisms are stacked with graphite blocks, the 3283500100013 average size of blocks is 19.86 x 19.86 x 30.01 cm3. 3283500100014 Graphite has a density of 1.653 g/cm. 3283500100015 DETECTOR (BF3) 2 BF3 detectors are 2 cm in diameter and 25 cm 3283500100016 long. The detector is covered with Cd tablet in 3283500100017 thickness of 0.5 mm and B4C in thickness of 2 cm. The 3283500100018 other 2 BF3 detector as monitors are placed in the 3283500100019 distance of 2 - 3 m and about 45 deg and 120 deg. 3283500100020 METHOD (DIFUS) In 1st measurement, the samples smaller than 3283500100021 119.39 x 119.17 x 79.88 cm3 are covered with borax in 3283500100022 thickness of 8 cm. The samples smaller than 79.45 x 3283500100023 79.45 x 90.03 cm3 are covered with borax in thickness 3283500100024 of 8 cm and paraffin in thickness of 10 cm. In 2nd 3283500100025 measurement, the samples smaller than 119.17 x 119.17 3283500100026 x 90.03 cm3 are covered with borax and paraffin. 3283500100027 CORRECTION The background is 0.3 - 0.6 %. The systematical error 3283500100028 from the size of graphite is 1%, and contained in the 3283500100029 uncertainty of average cross section. 3283500100030 STATUS (TABLE) Data are obtained from the Table 3 in 3283500100031 At.En.Sci.Technol,10,146,1976. 3283500100032 HISTORY (20230917C) Compiled by Yangyang Liu (CNDC) 3283500100033 ENDBIB 31 0 3283500100034 COMMON 1 3 3283500100035 EN 3283500100036 EV 3283500100037 0.0253 3283500100038 ENDCOMMON 3 0 3283500100039 ENDSUBENT 38 0 3283500199999 SUBENT 32835002 20230917 20240316 3283500200001 BIB 3 6 3283500200002 REACTION (6-C-0(N,ABS),,SIG) 3283500200003 FLAG (1.) 1st round measurement 3283500200004 (2.) 2nd round measurement 3283500200005 ERR-ANALYS (ERR-T) Total uncertainties 3283500200006 (ERR-1) Uncertainty of least squares 3283500200007 (ERR-2) Uncertainty of experiment 3283500200008 ENDBIB 6 0 3283500200009 NOCOMMON 0 0 3283500200010 DATA 5 2 3283500200011 DATA ERR-1 ERR-2 ERR-T FLAG 3283500200012 MB MB MB MB NO-DIM 3283500200013 4.00 0.08 0.04 0.12 1. 3283500200014 4.07 0.08 0.06 0.14 2. 3283500200015 ENDDATA 4 0 3283500200016 ENDSUBENT 15 0 3283500299999 SUBENT 32835003 20230917 20240316 3283500300001 BIB 4 4 3283500300002 REACTION (6-C-0(N,ABS),,SIG,,AV) 3283500300003 ANALYSIS Average of result from 1st and 2nd round measurements 3283500300004 ERR-ANALYS (DATA-ERR) Total uncertainty 3283500300005 STATUS (DEP,32835002) Individual measurements 3283500300006 ENDBIB 4 0 3283500300007 NOCOMMON 0 0 3283500300008 DATA 2 1 3283500300009 DATA DATA-ERR 3283500300010 MB MB 3283500300011 4.03 0.13 3283500300012 ENDDATA 3 0 3283500300013 ENDSUBENT 12 0 3283500399999 ENDENTRY 3 0 3283599999999