ENTRY 31418 20100308 31443141800000001 SUBENT 31418001 20100308 31443141800100001 BIB 15 70 3141800100002 TITLE Integral fission cross section ratios of Th-232, U-236 3141800100003 and U-238 relative to U-235 in the neutron spectrum 3141800100004 produced by 23.2 MeV deuterons incident on a thick Be 3141800100005 metal target. 3141800100006 AUTHOR (M.Bovisio de Ricabarra,L.Cohen de Porto,D.Waisman, 3141800100007 G.H.Ricabarra) 3141800100008 INSTITUTE (3ARGCNE) 3141800100009 REFERENCE (R,INDC(ARG)-010,199208) 3141800100010 (R,INDC(ARG)-011,199303) no. 4, only summary. 3141800100011 FACILITY (VDGT,3ARGCNE) 3141800100012 INC-SOURCE (D-BE) Deuteron energy was 23.2 MeV. 3141800100013 DETECTOR (TRD) Solid-state nuclear track detector (SSNTD) 3141800100014 packets, consisting of electroplated fission deposits 3141800100015 (samples) plus mica track detectors for fission 3141800100016 fragment counting, were placed at 41 mm from the beam 3141800100017 spot in the Be target at approx. 0 Degree. 3141800100018 METHOD (FISCT) The mica SSNTD detectors were etched and the 3141800100019 fission tracks were counted after irradiation to 3141800100020 determine the fission ratios. A cadmium shield behind 3141800100021 the irradiated stack was used to eliminate low-energy 3141800100022 neutrons back scattered by the room walls. 3141800100023 Mass assay was based on 2*Pi alpha counting for 3141800100024 uranium deposits and counting of Pa-233 produced by 3141800100025 thermal neutrons in Th-232 for thorium deposits. 3141800100026 PART-DET (FF) 3141800100027 INC-SPECT The neutron spectrum was determined with the unfolding 3141800100028 code SAND-II using a set of 11 measured activities, 3141800100029 the mean neutron energy for 0.3 - 23 MeV being 7.5 MeV 3141800100030 ( from M.A.Lone et al, Nucl. Instr. Meth., 143, 331- 3141800100031 334 (1977)). 3141800100032 ANALYSIS Fissions per atom were determined taking into account 3141800100033 deposits mass and isotopic composition. 3141800100034 CORRECTION Corrections have been made for fission fragment 3141800100035 absorption in the deposits, for beam current 3141800100036 fluctuations, for small flux differences due to 3141800100037 position in the stack and to different foil diameter, 3141800100038 and for alpha backscattering in the foil backing. 3141800100039 ERR-ANALYS (ERR-T) The main two elements to be considered in the 3141800100040 error estimation are mass assay and fission-track 3141800100041 counting. 3141800100042 The error in mass assay is determined by the 3141800100043 uncertainties in (%): 3141800100044 (ERR-1) U-235 alpha decay half life .07 3141800100045 (ERR-2) U-236 alpha decay half life .06 3141800100046 (ERR-3) U-238 alpha decay half life .05 3141800100047 (ERR-4) correction for alpha backscattering 3141800100048 in the foil backing 0.1 3141800100049 (ERR-5) thorium weight 0.1 3141800100050 (ERR-6) alpha desintegration ratio for natural uranium:3141800100051 (U234+U235+U238)/U238 0.5 3141800100052 alpha counting and corrections for alpha self- 3141800100053 absorption ( values not given explicitely in paper). 3141800100054 the error in fission track counting is determined by: 3141800100055 error in counting statistics ( no explicite value 3141800100056 given in original paper) and 3141800100057 systematic errors arising from fission rates 3141800100058 corrections, which are: 3141800100059 (ERR-7,2.,5.) position in stack 2 - 5 3141800100060 (ERR-8) stack to source distance 1.0 3141800100061 (ERR-9) fission fragment range in uraniumoxide 10. 3141800100062 (ERR-10) fission fragment range in thoriumoxide 30. 3141800100063 correction for fissions from other isotopes, 3141800100064 which depends on uncertainties in: 3141800100065 isotopic composition ( see under 'sample' 3141800100066 in subents 003 - 008) 3141800100067 (ERR-11) (calculated)integral fission cross section 5.3141800100068 STATUS (TABLE) Data are taken from Table 5 of INDC(ARG)-010. 3141800100069 HISTORY (19930714C) HW 3141800100070 (20100220A) SD:Updated to new date formats,lower case. 3141800100071 Cosmetic changes 3141800100072 ENDBIB 70 0 3141800100073 COMMON 11 6 3141800100074 EN-DUMMY ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 3141800100075 ERR-6 ERR-8 ERR-9 ERR-10 ERR-11 3141800100076 MEV PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 3141800100077 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 3141800100078 7.5 0.07 0.06 0.05 0.1 0.5 3141800100079 1. 1. 10. 30. 5. 3141800100080 ENDCOMMON 6 0 3141800100081 ENDSUBENT 80 0 3141800199999 SUBENT 31418002 20100308 31443141800200001 BIB 3 8 3141800200002 REACTION ((90-TH-232(N,F),,SIG,,SPA)/(92-U-238(N,F),,SIG,,SPA)) 3141800200003 SAMPLE Electroplated fission deposits of natural uranium 3141800200004 oxide and natural thorium oxide. 3141800200005 Composition of the natural uranium deposit being (%): 3141800200006 U234 U235 U236 U238 3141800200007 0.0055+-4. .72+-7. 0.0 99.2745 3141800200008 CORRECTION The U-238 fissions were 1.6% corrected for U-235 3141800200009 fissions. 3141800200010 ENDBIB 8 0 3141800200011 NOCOMMON 0 0 3141800200012 DATA 2 1 3141800200013 DATA ERR-T 3141800200014 NO-DIM PER-CENT 3141800200015 0.3110 3.18 3141800200016 ENDDATA 3 0 3141800200017 ENDSUBENT 16 0 3141800299999 SUBENT 31418003 20100308 31443141800300001 BIB 3 8 3141800300002 REACTION ((90-TH-232(N,F),,SIG,,SPA)/(92-U-238(N,F),,SIG,,SPA)) 3141800300003 SAMPLE Electroplated fission deposits of natural uranium 3141800300004 oxide and natural thorium oxide. 3141800300005 Composition of the natural uranium deposit being (%): 3141800300006 U234 U235 U236 U238 3141800300007 0.0055+-4. .72+-7. 0.0 99.2745 3141800300008 CORRECTION The U-238 fissions were 1.6% corrected for U-235 3141800300009 fissions. 3141800300010 ENDBIB 8 0 3141800300011 NOCOMMON 0 0 3141800300012 DATA 2 1 3141800300013 DATA ERR-T 3141800300014 NO-DIM PER-CENT 3141800300015 0.3084 3.18 3141800300016 ENDDATA 3 0 3141800300017 ENDSUBENT 16 0 3141800399999 SUBENT 31418004 20100308 31443141800400001 BIB 2 6 3141800400002 REACTION ((90-TH-232(N,F),,SIG,,SPA)/(92-U-238(N,F),,SIG,,SPA)) 3141800400003 SAMPLE Electroplated fission deposits of depleted uranium 3141800400004 oxide and natural thorium oxide, the isotopic 3141800400005 composition of the uranium deposit being (%): 3141800400006 U234 U235 U236 U238 3141800400007 0.0 .0023 +-2 0.0 99.9977 3141800400008 ENDBIB 6 0 3141800400009 NOCOMMON 0 0 3141800400010 DATA 2 1 3141800400011 DATA ERR-T 3141800400012 NO-DIM PER-CENT 3141800400013 0.3071 3.20 3141800400014 ENDDATA 3 0 3141800400015 ENDSUBENT 14 0 3141800499999 SUBENT 31418005 20100308 31443141800500001 BIB 3 8 3141800500002 REACTION ((90-TH-232(N,F),,SIG,,SPA)/(92-U-238(N,F),,SIG,,SPA)) 3141800500003 SAMPLE Electroplated fission deposits of natural uranium 3141800500004 oxide and natural thorium oxide. 3141800500005 Composition of the natural uranium deposit being (%): 3141800500006 U234 U235 U236 U238 3141800500007 0.0055+-4. .72+-7. 0.0 99.2745 3141800500008 CORRECTION The U-238 fissions were 1.6% corrected for U-235 3141800500009 fissions. 3141800500010 ENDBIB 8 0 3141800500011 NOCOMMON 0 0 3141800500012 DATA 2 1 3141800500013 DATA ERR-T 3141800500014 NO-DIM PER-CENT 3141800500015 0.3235 3.08 3141800500016 ENDDATA 3 0 3141800500017 ENDSUBENT 16 0 3141800599999 SUBENT 31418006 20100308 31443141800600001 BIB 3 11 3141800600002 REACTION ((92-U-238(N,F),,SIG,,SPA)/(92-U-235(N,F),,SIG,,SPA)) 3141800600003 SAMPLE Electroplated fission deposits of natural and enriched 3141800600004 uranium oxide, the isotopic 3141800600005 composition of the natural uranium deposit being (%): 3141800600006 U234 U235 U236 U238 3141800600007 0.0055+-4. .72+-7. 0.0 99.2745 3141800600008 and of the enriched uranium deposit being (%): 3141800600009 U234 U235 U236 U238 3141800600010 .57+-.88 95.27+-.01 0.0 4.16+-.12 3141800600011 CORRECTION The U-235 fissions were 2.5% corrected for U-234 3141800600012 and U-238 fissions. 3141800600013 ENDBIB 11 0 3141800600014 NOCOMMON 0 0 3141800600015 DATA 2 1 3141800600016 DATA ERR-T 3141800600017 NO-DIM PER-CENT 3141800600018 0.4569 2.42 3141800600019 ENDDATA 3 0 3141800600020 ENDSUBENT 19 0 3141800699999 SUBENT 31418007 20100308 31443141800700001 BIB 3 11 3141800700002 REACTION ((92-U-238(N,F),,SIG,,SPA)/(92-U-235(N,F),,SIG,,SPA)) 3141800700003 SAMPLE Electroplated fission deposits of depleted and 3141800700004 enriched uranium oxide, the isotopic 3141800700005 composition of the depleted uranium deposit being (%): 3141800700006 U234 U235 U236 U238 3141800700007 0.0 .0023 +-2 0.0 99.9977 3141800700008 and of the enriched uranium deposit (%): 3141800700009 U234 U235 U236 U238 3141800700010 .57+-.88 95.27+-.01 0.0 4.16+-.12 3141800700011 CORRECTION The U-235 fissions were 2.5% corrected for U-234 3141800700012 and U-238 fissions. 3141800700013 ENDBIB 11 0 3141800700014 NOCOMMON 0 0 3141800700015 DATA 2 1 3141800700016 DATA ERR-T 3141800700017 NO-DIM PER-CENT 3141800700018 0.4521 2.15 3141800700019 ENDDATA 3 0 3141800700020 ENDSUBENT 19 0 3141800799999 SUBENT 31418008 20100308 31443141800800001 BIB 3 11 3141800800002 REACTION ((92-U-236(N,F),,SIG,,SPA)/(92-U-235(N,F),,SIG,,SPA)) 3141800800003 SAMPLE Electroplated fission deposits of depleted and 3141800800004 U236-enriched uranium oxide, the isotopic 3141800800005 composition of the depleted uranium deposit being (%): 3141800800006 U234 U235 U236 U238 3141800800007 0.0 .0023 +-2 0.0 99.9977 3141800800008 and of the U236-enriched uranium deposit (%): 3141800800009 U234 U235 U236 U238 3141800800010 0.0 4.57+-.1 92.96+-.05 2.47+-.2 3141800800011 CORRECTION The U-236 fissions were 8.8% corrected for U-235 3141800800012 fissions. 3141800800013 ENDBIB 11 0 3141800800014 NOCOMMON 0 0 3141800800015 DATA 2 1 3141800800016 DATA ERR-T 3141800800017 NO-DIM PER-CENT 3141800800018 0.7081 2.1 3141800800019 ENDDATA 3 0 3141800800020 ENDSUBENT 19 0 3141800899999 ENDENTRY 8 0 3141899999999