ENTRY 20779 20170724 22622077900000001 SUBENT 20779001 20170724 22622077900100001 BIB 13 50 2077900100002 TITLE Absolute neutron fission cross sections of 235U, 238U, 2077900100003 and 239Pu at 13.9 and 14.6 MeV 2077900100004 AUTHOR (M.Cance, G.Grenier, D.Gimat, D.Parisot) 2077900100005 INSTITUTE (2FR BRC) 2077900100006 REFERENCE (J,NSE,68,197,1978) 2077900100007 (C,76ANL,,237,1976) Same 235U,238U(n,f) data 2077900100008 (C,75KIEV,5,363,1976) 14.6 MeV 235,238U data in table 2077900100009 (J,ANS,22,664,1975) Prelim. 235,238U data in table 2077900100010 FACILITY (VDG,2FR BRC) 550 keV Van de Graaff accelerator 2077900100011 INC-SOURCE (D-T) 210 keV deuterons (10 uA) of TiT (650 ug/cm2 2077900100012 thick) on a Ta backing (0.02 cm thick) 2077900100013 METHOD (ASSOP) 2077900100014 (TOF) to determine background due to alpha activity of 2077900100015 the deposit and due to fissions induced by unwanted 2077900100016 neutrons 2077900100017 (PHD) 2077900100018 PART-DET (N,A,FF) 2077900100019 DETECTOR (FISCH) Double 4-pi ionization chamber 2077900100020 (SOLST) To detect associated alpha at 70 deg 2077900100021 (En=13.9 MeV) or 125 deg (En=14.6 MeV) 2077900100022 (SCIN) Plastic scintillator (1.5 cm diam, 2.0 cm thick)2077900100023 served as a neutron monitor to count neutron-alpha 2077900100024 coincidences 2077900100025 CORRECTION Corrected for 2077900100026 - background 2077900100027 - ionization chamber efficiency 2077900100028 - extrapolation to zero pulse height (1.3%-2.3%)2077900100029 - loss of fissions (0.7%-0.9%)2077900100030 - neutron attenuation in target backing (1%-1.8%)2077900100031 - neutron attenuation in front face of fission chamber2077900100032 (1.5%)2077900100033 - fissions due to other isotopes (1%-3%)2077900100034 COMMENT By compiler (2017-07-24): 2077900100035 Table III of Nucl.Sci.Eng.68(1978)197 does not give 2077900100036 information on the energy dependence of the partial 2077900100037 uncertainties. The compiler kept only those expected 2077900100038 as constants of the neutron energy. 2077900100039 STATUS (TABLE) Table IV of Nucl.Sci.Eng.68(1978)197 2077900100040 HISTORY (19780320R) Special attached form with numerical 2077900100041 values from Grenier 2077900100042 (19781102C) 2077900100043 (19781213E) 2077900100044 (20071126A) Date is corrected 2077900100045 (20071127A) MISC heading determined. Error structure 2077900100046 given. DATA-ERR to ERR-T changed. Common value of 2077900100047 EN-ERR moved to SAN 001. SUBENTs cross reference 2077900100048 established 2077900100049 (20110223U) SD: in code METHOD keyword HE-AC deleted. 2077900100050 (20170724A) On. ERR-ANALYS moved to data subentries. 2077900100051 Major revision in 002-006. 2077900100052 ENDBIB 50 0 2077900100053 NOCOMMON 0 0 2077900100054 ENDSUBENT 53 0 2077900199999 SUBENT 20779002 20170724 22622077900200001 BIB 4 20 2077900200002 REACTION (92-U-235(N,F),,SIG) 2077900200003 SAMPLE Uranium acetate (60 mm in diam., 103.5 ug/cm2 thick) 2077900200004 electrosprayed on 20 ug/cm2 vyns foil metallized by 2077900200005 Al (20 ug/cm2 thick) 2077900200006 (92-U-235,ENR=0.9825) 2077900200007 (92-U-234,ENR=0.0146) 2077900200008 (92-U-236,ENR=0.0009) 2077900200009 (92-U-238,ENR=0.0020) 2077900200010 ERR-ANALYS (ERR-T) Quadrature sum of the following uncertainties: 2077900200011 - Statistics including background subtraction 2077900200012 - Extrapolation to zero pulse height 2077900200013 (0.6% for irradiation with 238U, 2077900200014 0.23% for irradiation with 239Pu) 2077900200015 (ERR-2) Loss of fissions (0.19%) 2077900200016 (ERR-3) Number of atoms per cm2 (1.4%) 2077900200017 (ERR-4) Neutron attenuation in target backing (0.36%) 2077900200018 (ERR-5) Neutron attenuation in front face of (0.3%) 2077900200019 fission chamber 2077900200020 (ERR-6) Fissions due to other isotopes (0.2%) 2077900200021 HISTORY (20170724A) On. ERR-ANALYS added. ERR-1, ERR-S deleted.2077900200022 ENDBIB 20 0 2077900200023 COMMON 5 3 2077900200024 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2077900200025 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2077900200026 0.19 1.4 0.36 0.3 0.2 2077900200027 ENDCOMMON 3 0 2077900200028 DATA 4 2 2077900200029 EN EN-ERR DATA ERR-T 2077900200030 MEV MEV B B 2077900200031 13.9 0.13 2.062 0.039 2077900200032 14.6 0.13 2.063 0.039 2077900200033 ENDDATA 4 0 2077900200034 ENDSUBENT 33 0 2077900299999 SUBENT 20779003 20170724 22622077900300001 BIB 4 18 2077900300002 REACTION (92-U-238(N,F),,SIG) 2077900300003 SAMPLE Uranium acetate 60 mm in diam., 75.8 ug/cm2 thick) 2077900300004 electrosprayed on 20 ug/cm2 vyns foil metallized by 2077900300005 Al (20 ug/cm2 thick) 2077900300006 (92-U-238,ENR=0.9805) 2077900300007 (92-U-234,ENR=0.0192) 2077900300008 (92-U-235,ENR=0.0003) 2077900300009 (92-U-236,ENR=0.0000) 2077900300010 ERR-ANALYS (ERR-T) Quadrature sum of the following uncertainties: 2077900300011 - Statistics including background subtraction 2077900300012 (ERR-1) Extrapolation to zero pulse height (0.7%) 2077900300013 (ERR-2) Loss of fissions (0.17%) 2077900300014 (ERR-3) Number of atoms per cm2 (1.35%) 2077900300015 (ERR-4) Neutron attenuation in target backing (0.36%) 2077900300016 (ERR-5) Neutron attenuation in front face of (0.3%) 2077900300017 fission chamber 2077900300018 (ERR-6) Fissions due to other isotopes (0.4%) 2077900300019 HISTORY (20170724A) On. ERR-ANALYS added. ERR-S deleted. 2077900300020 ENDBIB 18 0 2077900300021 COMMON 6 3 2077900300022 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2077900300023 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2077900300024 0.7 0.17 1.35 0.36 0.3 0.4 2077900300025 ENDCOMMON 3 0 2077900300026 DATA 4 2 2077900300027 EN EN-ERR DATA ERR-T 2077900300028 MEV MEV B B 2077900300029 13.9 0.13 1.143 0.025 2077900300030 14.6 0.13 1.149 0.025 2077900300031 ENDDATA 4 0 2077900300032 ENDSUBENT 31 0 2077900399999 SUBENT 20779004 20170724 22622077900400001 BIB 5 7 2077900400002 REACTION ((92-U-238(N,F),,SIG,,,DERIV)/ 2077900400003 (92-U-235(N,F),,SIG,,,DERIV)) 2077900400004 ANALYSIS Calculated from absolute measurements 2077900400005 ERR-ANALYS (DATA-ERR) Total uncertainty 2077900400006 STATUS (DEP,20779002) 235U(n,f) cross section 2077900400007 (DEP,20779003) 238U(n,f) cross section 2077900400008 HISTORY (20170724A) On. Parial uncertainties deleted. 2077900400009 ENDBIB 7 0 2077900400010 NOCOMMON 0 0 2077900400011 DATA 4 2 2077900400012 EN EN-ERR DATA DATA-ERR 2077900400013 MEV MEV NO-DIM NO-DIM 2077900400014 13.9 0.13 0.554 0.016 2077900400015 14.6 0.13 0.557 0.017 2077900400016 ENDDATA 4 0 2077900400017 ENDSUBENT 16 0 2077900499999 SUBENT 20779005 20170724 22622077900500001 BIB 4 17 2077900500002 REACTION (94-PU-239(N,F),,SIG) 2077900500003 SAMPLE Pu acetate (40 mm diam., 68 ug/cm2 thick) 2077900500004 electrosprayed on a vyns foil 2077900500005 (94-PU-239,ENR=0.9914) 2077900500006 (94-PU-238,ENR=0.000046) 2077900500007 (94-PU-240,ENR=0.00855) 2077900500008 (94-PU-242,ENR=0.0000038) 2077900500009 ERR-ANALYS (ERR-T) Quadrature sum of the following uncertainties: 2077900500010 - Statistics including background subtraction 2077900500011 (ERR-1) Extrapolation to zero pulse height (0.3%)2077900500012 (ERR-2) Loss of fissions (0.15%)2077900500013 (ERR-3) Number of atoms per cm2 (1.36%)2077900500014 (ERR-4) Neutron attenuation in target backing (0.36%)2077900500015 (ERR-5) Neutron attenuation in front face of 2077900500016 fission chamber (0.3%)2077900500017 (ERR-6) Fissions due to other isotopes (0.17%)2077900500018 HISTORY (20170724A) On. ERR-ANALYS added. ERR-S deleted. 2077900500019 ENDBIB 17 0 2077900500020 COMMON 6 3 2077900500021 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 2077900500022 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2077900500023 0.3 0.15 1.36 0.36 0.3 0.17 2077900500024 ENDCOMMON 3 0 2077900500025 DATA 4 2 2077900500026 EN EN-ERR DATA ERR-T 2077900500027 MEV MEV B B 2077900500028 13.9 0.13 2.321 0.058 2077900500029 14.6 0.13 2.290 0.052 2077900500030 ENDDATA 4 0 2077900500031 ENDSUBENT 30 0 2077900599999 SUBENT 20779006 20170724 22622077900600001 BIB 5 7 2077900600002 REACTION ((94-PU-239(N,F),,SIG,,,DERIV)/ 2077900600003 (92-U-235(N,F),,SIG,,,DERIV)) 2077900600004 ANALYSIS Calculated from absolute measurements 2077900600005 ERR-ANALYS (DATA-ERR) Total uncertainty 2077900600006 STATUS (DEP,20779002) 235U(n,f) cross section 2077900600007 (DEP,20779005) 238U(n,f) cross section 2077900600008 HISTORY (20170724A) On. Parial uncertainties deleted. 2077900600009 ENDBIB 7 0 2077900600010 NOCOMMON 0 0 2077900600011 DATA 4 2 2077900600012 EN EN-ERR DATA DATA-ERR 2077900600013 MEV MEV NO-DIM NO-DIM 2077900600014 13.9 0.13 1.125 0.035 2077900600015 14.6 0.13 1.110 0.033 2077900600016 ENDDATA 4 0 2077900600017 ENDSUBENT 16 0 2077900699999 ENDENTRY 6 0 2077999999999