ENTRY 21620 20170721 22622162000000001 SUBENT 21620001 20170721 22622162000100001 BIB 14 54 2162000100002 TITLE Absolute fission cross-section measurements of 235U 2162000100003 at 2.5 and 4.45 MeV, and 241Am at 14.6 MeV neutron 2162000100004 energies 2162000100005 AUTHOR (M.Cance, G.Grenier) 2162000100006 INSTITUTE (2FR BRC) 2162000100007 REFERENCE (R,CEA-N-2194,1981) 2162000100008 (C,78HARWELL,864,1978) Prelim. data at 2.5 MeV in table2162000100009 REL-REF (O,21621001,M.Cance+,R,CEA-N-2194,1981) 2162000100010 241Am(n,f) cross section at 14.6 MeV given 2162000100011 FACILITY (VDG) 4 MV Van De Graaff accelerator 2162000100012 INC-SOURCE (P-T) En=2.5 MeV 2162000100013 (D-D) En=4.45 MeV 2162000100014 SAMPLE U3O8 (103.2 ug/cm2) onto a Ta backing (0.3 mm thick). 2162000100015 The number of 235U atoms was determined by low 2162000100016 geometry alpha-counting. 2162000100017 (92-U-235,ENR=0.97663) 2162000100018 (92-U-234,ENR=0.016653) 2162000100019 (92-U-236,ENR=0.001491) 2162000100020 (92-U-238,ENR=0.005229) 2162000100021 METHOD (TOF) 2162000100022 CORRECTION The following corrections were taken into account, 2162000100023 - Fission detector 2162000100024 . extrapolation to zero spectrum amplitude, 2162000100025 . loss of fission events, 2162000100026 . fission events due to other isotopes, 2162000100027 . fission events due to scattered neutrons, 2162000100028 . fisison events without neutron producing target. 2162000100029 - Telescope 2162000100030 . events without polyethylene radiator, 2162000100031 . events without neutron production target, 2162000100032 . neutron attenuation in backing materials. 2162000100033 - Long counter (only at 2.5 MeV), 2162000100034 . background without neutron production target, 2162000100035 . background from shadow-bar, 2162000100036 . neutron attenuation in air and in the hybrid 2162000100037 detector. 2162000100038 ERR-ANALYS (ERR-T) Total uncertainty 2162000100039 (ERR-1) Extrapolation to zero spectrum amplitude for 2162000100040 fission detection (0.1%)2162000100041 (ERR-2) Loss of fission events (0.1%)2162000100042 (ERR-3) Fission of due to other isotopes (0.2%)2162000100043 (ERR-4) Fission due to scattered neutrons (0.3%-0.5%)2162000100044 (ERR-6) Number of 235U atoms (0.5%)2162000100045 (ERR-7,,,U) Fission counting (0.7%-1.1%)2162000100046 (ERR-8) Geometrical factors (0.4%-0.5%)2162000100047 ADD-RES The average of cross sections from the telescope and 2162000100048 BF3 measurements is 1.26+/-0.03 b at 2.5+/-0.04 MeV. 2162000100049 STATUS (TABLE) Table 4 of CEA-N-2194 2162000100050 HISTORY (19800711C) G.C. 2162000100051 (19800808E) 2162000100052 (19820408A) Updated with main reference 2162000100053 (19820921E) 2162000100054 (20170721A) On. ERR-ANALYS updated. Major rev. in 2162000100055 002-003. 2162000100056 ENDBIB 54 0 2162000100057 COMMON 4 3 2162000100058 ERR-1 ERR-2 ERR-3 ERR-6 2162000100059 PER-CENT PER-CENT PER-CENT PER-CENT 2162000100060 0.1 0.1 0.2 0.5 2162000100061 ENDCOMMON 3 0 2162000100062 ENDSUBENT 61 0 2162000199999 SUBENT 21620002 20170721 22622162000200001 BIB 6 20 2162000200002 REACTION (92-U-235(N,F),,SIG) 2162000200003 MONITOR (1-H-1(N,EL)1-H-1,,SIG) 2162000200004 DETECTOR (FISCH) 2162000200005 (TELES,SOLST,SOLST) Hybrid detector with the fission 2162000200006 foil and a polyethylene foil (radiator) mounted 2162000200007 back-to-back. 2162000200008 ERR-ANALYS (ERR-5) Fission without neutron production target 2162000200009 at 4.45 MeV (0.7%)2162000200010 (ERR-9) Event without polyethylene radiator (0.9%-1.2%)2162000200011 (ERR-10) Events without neutron production target 2162000200012 (0.1%-0.3%)2162000200013 (ERR-11) Neutron attenuation in backing materials(0.1%)2162000200014 (ERR-12) n-p scattering cross section (0.75%)2162000200015 (ERR-13) Number of hydrogen atoms (0.2%)2162000200016 (ERR-14) Efficiency (0.3%)2162000200017 (ERR-15,,,U) Statistics (0.3%-0.5%)2162000200018 STATUS (COREL,21620003) Data with BF3 counter 2162000200019 HISTORY (19820408A) 2162000200020 (20170721A) On. ERR-ANALYS updated. BF3 data moved 2162000200021 from 002 to 003. EN-RSL -> EN-RSL-HW 2162000200022 ENDBIB 20 0 2162000200023 COMMON 4 3 2162000200024 ERR-11 ERR-12 ERR-13 ERR-14 2162000200025 PER-CENT PER-CENT PER-CENT PER-CENT 2162000200026 0.1 0.75 0.2 0.3 2162000200027 ENDCOMMON 3 0 2162000200028 DATA 11 2 2162000200029 EN EN-RSL-HW DATA ERR-T ERR-4 ERR-5 2162000200030 ERR-7 ERR-8 ERR-9 ERR-10 ERR-15 2162000200031 MEV MEV B PER-CENT PER-CENT PER-CENT 2162000200032 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2162000200033 2.5 0.04 1.28 1.7 0.5 2162000200034 0.7 0.5 0.9 0.1 0.3 2162000200035 4.45 0.1 1.13 2.2 0.3 0.7 2162000200036 1.1 0.4 1.2 0.3 0.5 2162000200037 ENDDATA 8 0 2162000200038 ENDSUBENT 37 0 2162000299999 SUBENT 21620003 20170721 22622162000300001 BIB 6 10 2162000300002 REACTION (92-U-235(N,F),,SIG) 2162000300003 MONITOR (5-B-10(N,A)3-LI-7,,SIG) 2162000300004 DETECTOR (FISCH) 2162000300005 (BF3) Directional long counter 2162000300006 ERR-ANALYS (ERR-9) Background from shadow-bar (0.4%) 2162000300007 (ERR-10) Neutron attenuation in air (0.3%) 2162000300008 (ERR-11) Neutron attenuation in hybrid detector (0.3%) 2162000300009 (ERR-12) Efficiency (2.5%) 2162000300010 STATUS (COREL,21620003) Data with proton counter telescope 2162000300011 HISTORY (20170721C) On 2162000300012 ENDBIB 10 0 2162000300013 COMMON 4 3 2162000300014 ERR-9 ERR-10 ERR-11 ERR-12 2162000300015 PER-CENT PER-CENT PER-CENT PER-CENT 2162000300016 0.4 0.3 0.3 2.5 2162000300017 ENDCOMMON 3 0 2162000300018 DATA 7 1 2162000300019 EN EN-RSL-HW DATA ERR-T ERR-4 ERR-7 2162000300020 ERR-8 2162000300021 MEV MEV B PER-CENT PER-CENT PER-CENT 2162000300022 PER-CENT 2162000300023 2.5 0.04 1.23 2.8 0.5 0.7 2162000300024 0.5 2162000300025 ENDDATA 6 0 2162000300026 ENDSUBENT 25 0 2162000399999 ENDENTRY 3 0 2162099999999