ENTRY 32624 20200825 31973262400000001 SUBENT 32624001 20200825 31973262400100001 BIB 12 53 3262400100002 TITLE Measurement of thermal neutrons fission cross section 3262400100003 ratio for U-233, U-235. 3262400100004 AUTHOR (Jia Wenhai, Yan Wuguang, Ye Zongyuan, Huan Wenyong, 3262400100005 Yuan Hanrong) 3262400100006 INSTITUTE (3CPRAEP) 3262400100007 REFERENCE (J,CST,9,19,1975) 3262400100008 FACILITY (REAC,3CPRAEP) Heavy-water reactor 3262400100009 INC-SOURCE (REAC) Neutron beam from the horizontal experimental 3262400100010 hole incident into a NaCl(200) crystal monochromator. 3262400100011 After Bragg diffraction by the monochromator, the 3262400100012 0.0253 eV monochromatic neutron beam was obtained 3262400100013 which passed through a simple chopper monochromator 3262400100014 to reduce the higher-order diffracted neutrons 3262400100015 component. 3262400100016 SAMPLE Uranium was electroplated on a platinum foil. 3262400100017 The uranium layer was 26 mm in diameter, 400 ug/cm2 3262400100018 in thickness. 3262400100019 The total weight was 3262400100020 2.1132 mg for the 233U sample, 3262400100021 1.9983 mg for the 235U sample(1), 3262400100022 2.1602 mg for the 235U sample(2). 3262400100023 The isotopic composition for the samples by mass 3262400100024 spectrographic analysis was as follows: 3262400100025 ---------------------------------------------------- 3262400100026 Isotope 233U sample 235U sample(1) 235U sample(2) 3262400100027 ---------------------------------------------------- 3262400100028 233U 99.0+/-0.5 3262400100029 234U 0.4+/-0.1 1.15+/-0.10 1.0+/-0.1 3262400100030 235U 0.4+/-0.1 90.0 +/-0.9 90.5+/-0.9 3262400100031 236U 0.15+/-0.10 3262400100032 238U 0.2+/-0.1 8.4 +/-0.7 8.5+/-0.8 3262400100033 ---------------------------------------------------- 3262400100034 DETECTOR (FISCH) Back-to-back ionization chamber filled with 3262400100035 1 atom argon (95.0%) and methane (5.0%) containing 3262400100036 the 233U and 235U samples 3262400100037 CORRECTION Corrected for 3262400100038 - neutron flux attenuation due to passing through the 3262400100039 ahead sample including the backing. 3262400100040 - fission counts due to the 235U impurity in the 233U 3262400100041 sample. 3262400100042 ERR-ANALYS (ERR-T) The total error (2.1%) propagated from 3262400100043 (ERR-1) 233U(n,f) counting statistics (0.25%) 3262400100044 (ERR-2) 235U(n,f) counting statistics (0.25%) 3262400100045 (ERR-3) 233U Sample mass (1.10%) 3262400100046 (ERR-4) 235U Sample mass (1.50%) 3262400100047 (ERR-5) 233U Fission detection efficiency (0.80%) 3262400100048 (ERR-6) 235U Fission detection efficiency (0.40%) 3262400100049 (ERR-7) Self-attenuation of neutron flux (0.20%) 3262400100050 (ERR-8,,0.1) 235U impurity in the 233U sample (<0.1%) 3262400100051 STATUS (TABLE) Table 3 of At.Energy Sci.Technol.9,(1975)19 3262400100052 HISTORY (19950225C) Compiled by Liang Qichang (CNDC) 3262400100053 (20100219U) SD:Updated to new date formats,lower case. 3262400100054 (20200825A) On. ERR-ANALYS updated. 3262400100055 ENDBIB 53 0 3262400100056 COMMON 7 6 3262400100057 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 3262400100058 ERR-7 3262400100059 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 3262400100060 PER-CENT 3262400100061 0.25 0.25 1.10 1.50 0.80 0.40 3262400100062 0.20 3262400100063 ENDCOMMON 6 0 3262400100064 ENDSUBENT 63 0 3262400199999 SUBENT 32624002 20200825 31973262400200001 BIB 2 2 3262400200002 REACTION ((92-U-233(N,F),,SIG)/(92-U-235(N,F),,SIG)) 3262400200003 HISTORY (20200825A) On. EN=0.0253 eV moved from 001 3262400200004 ENDBIB 2 0 3262400200005 NOCOMMON 0 0 3262400200006 DATA 3 1 3262400200007 EN DATA ERR-T 3262400200008 EV NO-DIM NO-DIM 3262400200009 0.0253 0.916 0.018 3262400200010 ENDDATA 3 0 3262400200011 ENDSUBENT 10 0 3262400299999 SUBENT 32624003 20200825 31973262400300001 BIB 4 7 3262400300002 REACTION (92-U-233(N,F),,SIG) 3262400300003 MONITOR (92-U-235(N,F),,SIG,,AV) 3262400300004 The weighted average of some selected experimental 3262400300005 data for 235U published from 1953 to 1973 was used as 3262400300006 the reference cross section. 3262400300007 STATUS (DEP,32604002) 233U(n,f)/235U(n,f) cross section ratio 3262400300008 HISTORY (20200825A) On. EN=0.0253 eV moved from 001 3262400300009 ENDBIB 7 0 3262400300010 NOCOMMON 0 0 3262400300011 DATA 5 1 3262400300012 EN DATA ERR-T MONIT MONIT-ERR 3262400300013 EV B B B B 3262400300014 0.0253 536. 11. 585. 2. 3262400300015 ENDDATA 3 0 3262400300016 ENDSUBENT 15 0 3262400399999 ENDENTRY 3 0 3262499999999