ENTRY 23185 20121017 22332318500000001 SUBENT 23185001 20121017 22332318500100001 BIB 11 26 2318500100002 TITLE Cross-Section Measurement of Thermal Neutron-Induced 2318500100003 Fission on 243Cm 2318500100004 AUTHOR (L.Popescu, J.Heyse, J.Wagemans, C.Wagemans) 2318500100005 INSTITUTE (2BLGMOL) L.Popescu, J.Heyse, J.Wagemans 2318500100006 (2BLGGHT) C.Wagemans 2318500100007 REFERENCE (J,NSE,171,204,2012) 2318500100008 FACILITY (REAC,2BLGMOL) Z59 irradiation channel (B-side) of the 2318500100009 BR1 reactor at SCK CEN - graphite-moderated air-cooled 2318500100010 system, using natU as fuel. Power of 700 kW. 2318500100011 INC-SOURCE (REAC) Neutron beam of diameter of 2 cm. 2318500100012 INC-SPECT Measured thermal neutron flux at the 243Cm sample 2318500100013 position was 6E+5 cm**-2/sec. 2318500100014 MONITOR (5-B-10(N,A)3-LI-7,,SIG) 2318500100015 For neutron flux monitoring. 2318500100016 PART-DET (FF,A) 2318500100017 DETECTOR (IMPSI) 50-mm-diam charged particle detector of 2318500100018 passivated implanted planar silicon PIPS type, 2318500100019 positioned in the beam at 8.3 cm from the 243Cm sample;2318500100020 for FF detection in solid angle of about 0.27 sr. 2318500100021 Alpha particles emitted in the B-10(n,a) reactions were2318500100022 detected with a 12-mm diam. PIPS detector positioned 2318500100023 outside the beam at 4.5 cm from the 10B sample. 2318500100024 HISTORY (20121017C) M.M. 2318500100025 (20121226U) Free text in REL-REF (explanation of code 2318500100026 B,NEUT.RES) was deleted in Subent 002 according to 2318500100027 comment of N.Otsuka (NDS,IAEA). 2318500100028 ENDBIB 26 0 2318500100029 NOCOMMON 0 0 2318500100030 ENDSUBENT 29 0 2318500199999 SUBENT 23185002 20121017 22332318500200001 BIB 9 66 2318500200002 REACTION (96-CM-243(N,F),,SIG) 2318500200003 SAMPLE - 94.65% enriched 243Cm-oxide sample containing 2318500200004 2.320 +- 0.025 microg of 243Cm. 2318500200005 (96-CM-243,ENR=0.9465) 5.77E+15 atoms 2318500200006 (96-CM-244,ENR=0.0429) 2.62E+14 atoms 2318500200007 (96-CM-245,ENR=0.0007) 4.01E+12 atoms 2318500200008 (96-CM-246,ENR=0.0094) 5.72E+13 atoms 2318500200009 (96-CM-247,ENR=0.0002) 1.34E+12 atoms 2318500200010 (96-CM-248,ENR=0.0003) 1.70E+12 atoms 2318500200011 239Pu 7.89E+13 atoms . 2318500200012 - U sample with a mass of 193.29+-1.33 microg, 99.94% 2318500200013 enrichment in 235U. 2318500200014 (92-U-233,ENR=0.00001) 4.99E+12 atoms 2318500200015 (92-U-234,ENR=0.00036) 1.79E+14 atoms 2318500200016 (92-U-235,ENR=0.99939) 4.95E+17 atoms 2318500200017 (92-U-236,ENR=0.00011) 5.42E+13 atoms 2318500200018 (92-U-238,ENR=0.00013) 6.36E+13 atoms 2318500200019 (number of atoms at time of measurement). 2318500200020 Cm and U samples were produced by vacuum deposition of 2318500200021 fissile material on identical aluminum backings of 2318500200022 20-microm thickness and 70-mm diameter, fixed in 2318500200023 identical aluminum frames and with a spot size of 15-mm2318500200024 diameter. 2318500200025 - B-10 sample - to monitor neutron beam by (n,alpha) - 2318500200026 46 +- 4 microg 10B/cm**2 . 2318500200027 ANALYSIS For obtaining the cross section of the 243Cm(n,f) 2318500200028 the relation was used: 2318500200029 Y=e*F*SUM(Gi*Ni*SIGi), where 2318500200030 Y - count rate, 2318500200031 e - detection efficiency, 2318500200032 F - neutron flux, 2318500200033 Gi - Westcott g-factor, 2318500200034 Ni - number of atoms, 2318500200035 SIGi - fission c-s at 25.3 eV 2318500200036 for i-th isotope considered, i from 1 to 7 for Cm. 2318500200037 The fission count rate measured with the 235U sample 2318500200038 can be expressed in similar way and the factor e*F can 2318500200039 be determined. 2318500200040 See ASSUMED data from REL-REF. 2318500200041 ASSUMED (ASSUM1,96-CM-244(N,F),,SIG) Westcott g-factor 0.9890 2318500200042 (ASSUM2,96-CM-245(N,F),,SIG) Westcott g-factor 0.9539 2318500200043 (ASSUM3,96-CM-246(N,F),,SIG) 2318500200044 (ASSUM4,96-CM-247(N,F),,SIG) 2318500200045 (ASSUM5,96-CM-248(N,F),,SIG) 2318500200046 Others assumed data used in analysis were coded as 2318500200047 MISC-data, because there are no codes for 2318500200048 ASSUM6 - ASSUM11 headings. 2318500200049 MISC-COL (MISC1)94-PU-239(N,F),,SIG, Westcott g-factor 1.0553 2318500200050 (MISC2)92-U-233(N,F),,SIG, Westcott g-factor 0.9955 2318500200051 (MISC3)92-U-234(N,F),,SIG, 2318500200052 (MISC4)92-U-235(N,F),,SIG, Westcott g-factor 0.9771 2318500200053 (MISC5)92-U-236(N,F),,SIG, 2318500200054 (MISC6)92-U-238(N,F),,SIG 2318500200055 REL-REF (R,,S.F.Mughabghab,B,NEUT.RES,,2006) 2318500200056 CORRECTION Contributions from spontaneous fission are negligible, 2318500200057 what was checked when the reactor was shut down. 2318500200058 Contributions from the epithermal component of the beam2318500200059 were also estimated by filtering the beam with a 2318500200060 1-mm-thick Cd foil, provided a cutoff energy of 0.55eV.2318500200061 The recorded fission spectrum amounts to 3.16% of the 2318500200062 spectrum recorded without the cadmium filter. 2318500200063 For the 243Cm measurement, corrections for temperature 2318500200064 variations during measurement cycle 2318500200065 ERR-ANALYS (ERR-S) Statistical uncertainty 2318500200066 (ERR-SYS) Systematical uncertainty 2318500200067 STATUS (TABLE) Table III of J,NSE,171,204,2012. 2318500200068 ENDBIB 66 0 2318500200069 COMMON 11 6 2318500200070 ASSUM1 ASSUM2 ASSUM3 ASSUM4 ASSUM5 MISC1 2318500200071 MISC2 MISC3 MISC4 MISC5 MISC6 2318500200072 B B B B B B 2318500200073 B B B B B 2318500200074 1.04 2144. 0.14 81.9 0.37 748.1 2318500200075 529.1 0.067 582.6 0.066 3.E-6 2318500200076 ENDCOMMON 6 0 2318500200077 DATA 4 1 2318500200078 EN DATA ERR-S ERR-SYS 2318500200079 MILLI-EV B B B 2318500200080 25.3 666. 6. 20. 2318500200081 ENDDATA 3 0 2318500200082 ENDSUBENT 81 0 2318500299999 SUBENT 23185003 20121017 22332318500300001 BIB 9 68 2318500300002 REACTION (96-CM-243(N,F),,SIG) 2318500300003 SAMPLE - 94.65% enriched 243Cm-oxide sample containing 2318500300004 2.320 +- 0.025 microg of 243Cm. 2318500300005 (96-CM-243,ENR=0.9465) 5.77E+15 atoms 2318500300006 (96-CM-244,ENR=0.0429) 2.62E+14 atoms 2318500300007 (96-CM-245,ENR=0.0007) 4.01E+12 atoms 2318500300008 (96-CM-246,ENR=0.0094) 5.72E+13 atoms 2318500300009 (96-CM-247,ENR=0.0002) 1.34E+12 atoms 2318500300010 (96-CM-248,ENR=0.0003) 1.70E+12 atoms 2318500300011 239Pu 7.89E+13 atoms . 2318500300012 - U sample with a mass of 193.29+-1.33 microg, 99.94% 2318500300013 enrichment in 235U. 2318500300014 (92-U-233,ENR=0.00001) 4.99E+12 atoms 2318500300015 (92-U-234,ENR=0.00036) 1.79E+14 atoms 2318500300016 (92-U-235,ENR=0.99939) 4.95E+17 atoms 2318500300017 (92-U-236,ENR=0.00011) 5.42E+13 atoms 2318500300018 (92-U-238,ENR=0.00013) 6.36E+13 atoms 2318500300019 (number of atoms at time of measurement). 2318500300020 Cm and U samples were produced by vacuum deposition of 2318500300021 fissile material on identical aluminum backings of 2318500300022 20-microm thickness and 70-mm diameter, fixed in 2318500300023 identical aluminum frames and with a spot size of 15-mm2318500300024 diameter. 2318500300025 - B-10 sample - to monitor neutron beam by (n,alpha) - 2318500300026 46 +- 4 microg 10B/cm**2 . 2318500300027 ANALYSIS For obtaining the cross section of the 243Cm(n,f) 2318500300028 the relation was used: 2318500300029 Y=e*F*SUM(Gi*Ni*SIGi), where 2318500300030 Y - count rate, 2318500300031 e - detection efficiency, 2318500300032 F - neutron flux, 2318500300033 Gi - Westcott g-factor, 2318500300034 Ni - number of atoms, 2318500300035 SIGi - fission c-s at 25.3 eV 2318500300036 for i-th isotope considered, i from 1 to 7 for Cm. 2318500300037 The fission count rate measured with the 235U sample 2318500300038 can be expressed in similar way and the factor e*F can 2318500300039 be determined. 2318500300040 See ASSUMED data from REL-REF. 2318500300041 ASSUMED (ASSUM1,96-CM-244(N,F),,SIG) Westcott g-factor 0.98902 2318500300042 (ASSUM2,96-CM-245(N,F),,SIG) Westcott g-factor 0.94769 2318500300043 (ASSUM3,96-CM-246(N,F),,SIG) Westcott g-factor 1.00260 2318500300044 (ASSUM4,96-CM-247(N,F),,SIG) Westcott g-factor 0.97686 2318500300045 (ASSUM5,96-CM-248(N,F),,SIG) Westcott g-factor 1.00120 2318500300046 Others assumed data used in analysis were coded as 2318500300047 MISC-data, because there are no codes for 2318500300048 ASSUM6 - ASSUM11 headings. 2318500300049 MISC-COL (MISC1)94-PU-239(N,F),,SIG, Westcott g-factor 1.04990 2318500300050 (MISC2)92-U-233(N,F),,SIG, Westcott g-factor 0.99632 2318500300051 (MISC3)92-U-234(N,F),,SIG, Westcott g-factor 0.99050 2318500300052 (MISC4)92-U-235(N,F),,SIG, Westcott g-factor 0.97660 2318500300053 (MISC5)92-U-236(N,F),,SIG, Westcott g-factor 1.00240 2318500300054 (MISC6)92-U-238(N,F),,SIG, Westcott g-factor 1.00130 2318500300055 REL-REF (R,,,3,JEFF-3.1.1,,2009) 2318500300056 The JEFF-3.1.1 Nuclear Data Library, A.Santamarina+, 2318500300057 JEFF Report 22, Nuclear Energy Agency, 2009. 2318500300058 CORRECTION Contributions from spontaneous fission are negligible, 2318500300059 what was checked when the reactor was shut down. 2318500300060 Contributions from the epithermal component of the beam2318500300061 were also estimated by filtering the beam with a 2318500300062 1-mm-thick Cd foil, provided a cutoff energy of 0.55eV.2318500300063 The recorded fission spectrum amounts to 3.16% of the 2318500300064 spectrum recorded without the cadmium filter. 2318500300065 For the 243Cm measurement, corrections for temperature 2318500300066 variations during measurement cycle. 2318500300067 ERR-ANALYS (ERR-S) Statistical uncertainty 2318500300068 (ERR-SYS) Systematical uncertainty 2318500300069 STATUS (TABLE) Table III of J,NSE,171,204,2012. 2318500300070 ENDBIB 68 0 2318500300071 COMMON 11 6 2318500300072 ASSUM1 ASSUM2 ASSUM3 ASSUM4 ASSUM5 MISC1 2318500300073 MISC2 MISC3 MISC4 MISC5 MISC6 2318500300074 B B B B B B 2318500300075 B B B B B 2318500300076 0.60 2141.12 0.14 81.78 0.37 747.99 2318500300077 531.24 0.67 584.98 0.06 0.00 2318500300078 ENDCOMMON 6 0 2318500300079 DATA 4 1 2318500300080 EN DATA ERR-S ERR-SYS 2318500300081 MILLI-EV B B B 2318500300082 25.3 668. 6. 20. 2318500300083 ENDDATA 3 0 2318500300084 ENDSUBENT 83 0 2318500399999 SUBENT 23185004 20121017 22332318500400001 BIB 4 7 2318500400002 REACTION (96-CM-243(N,F),,SIG) 2318500400003 ANALYSIS Average of two different normalizations. 2318500400004 ERR-ANALYS (DATA-ERR) The uncertainty excludes the uncertainty on 2318500400005 the Westcott factor. 2318500400006 STATUS (TABLE) Table IV of J,NSE,171,204,2012. 2318500400007 (DEP,23185002) See 2318500400008 (DEP,23185003) ANALYSIS. 2318500400009 ENDBIB 7 0 2318500400010 NOCOMMON 0 0 2318500400011 DATA 3 1 2318500400012 EN DATA DATA-ERR 2318500400013 MILLI-EV B B 2318500400014 25.3 667. 26. 2318500400015 ENDDATA 3 0 2318500400016 ENDSUBENT 15 0 2318500499999 ENDENTRY 4 0 2318599999999