ENTRY 41514 20120214 41564151400000001 SUBENT 41514001 20120214 41564151400100001 BIB 15 73 4151400100002 TITLE Measurement of the Am-242g (T1/2=16.02hour) fission 4151400100003 cross section . 4151400100004 AUTHOR (E.F.Fomushkin, V.V.Gavrilov, M.F.Andreev,A.M.Shvetsov,4151400100005 V.N.Vyachin, N.I.Iosilevich, A.A.Portnov, V.I.Kvasov, 4151400100006 A.F.Kozhin, A.F.Redkin, M.Chadwick, T.Kawano) 4151400100007 INSTITUTE (4RUSMIF) A.A.Portnov,V.I.Kvasov,A.F.Kozhin,A.F.Redkin 4151400100008 (4RUSEPA) E.F.Fomushkin, V.V.Gavrilov, M.F.Andreev, 4151400100009 A.M.Shvetsov, V.N.Vyachin, N.I.Iosilevich 4151400100010 (1USALAS) M.Chadwick, T.Kawano 4151400100011 REFERENCE (C,2007NICE,1,425,200704) 4151400100012 (A,2011SAROV,63,2011) 4151400100013 (W,FOMUSHKIN,201110) Text of report for 2011SAROV from 4151400100014 E.Fomushkin via N.Otsuka. 4151400100015 (A,2007NICE,69(#199),200704) #199 Abstract book. 4151400100016 FACILITY (REAC,4RUSMIF) IRT-MEPhI reactor. 4151400100017 INC-SOURCE (REAC) VEC-25 and VEC-28 channels. 4151400100018 INC-SPECT Thermal maxwellian neutron flux and cadmium ratio were 4151400100019 determined experimentally by capture in gold,as a rule.4151400100020 For VEC-25 - neutron flux 1.98E13 n/cm**2/sec, 4151400100021 cadmium ratio 5.06 . 4151400100022 For VEC-28 - neutron flux 5.75E10 n/cm**2/sec, 4151400100023 cadmium ratio 13.5 . 4151400100024 Error of neutron flux about 4 % . 4151400100025 SAMPLE Am-241 of high enrichment. Relative content of Am-242m4151400100026 and Am-243 atoms in samples < 3.E-6. Electrodeposition4151400100027 from alcoholic solution was used for fission samples, 4151400100028 spot diameter 6.0+-0.1 mm . 4151400100029 For radiative capture - several ampules of quartz 4151400100030 glass containing purified nitrate of Am-241. 4151400100031 Am-241 content in layers from 12.9 to 16.8 microg, 4151400100032 in ampoules - from 32.3 to 35.5 microg . 4151400100033 U-235 or Pu-239 certified layers - for additional 4151400100034 control and normalization. 4151400100035 DETECTOR (HPGE) Coaxial semiconductor detector of extra-purity 4151400100036 germanium - for flux measurements. 4151400100037 (TRD) Dielectric track detectors - plates of silicate 4151400100038 glass of 6.00+-0.02 mm diameter at 6.00+-0.02 mm 4151400100039 distance from surface layer. Probability of one of 4151400100040 fission fragments hit to the area of detector sensitive4151400100041 surface - (9.37+-0.10)% . 4151400100042 METHOD (ACTIV) Three layers of Am-241 (3.60, 4.05, 3.19 10**64151400100043 nuclei of Am) in aluminum chambers were irradiated in 4151400100044 VEC-25 within 30min, 1.0hour, 1.5hour, respectively . 4151400100045 Immediately after irradiation dielectric track 4151400100046 detectors were established in chambers,and measurements4151400100047 were continued in VEC-28. 4151400100048 Irradiation with and without cadmium. 4151400100049 (ASPEC) Alpha-particle spectra were registered by 4151400100050 semiconductor alpha-spectrometer with 30keV resolution.4151400100051 Two ampoules with Am-241 nitrate were irradiated in 4151400100052 VEC-25 within 69.6 hour (neutron fluence 4151400100053 (0.495+-0.021)*10**19 n/cm**2) . 4151400100054 DECAY-DATA (96-CM-242,,A,6113.,,A,6069.) by B-decay of Am-242g. 4151400100055 (95-AM-241,,A,5485.,,A,5443.) 4151400100056 Relative yield of Cm-242 alpha-particles to yield of 4151400100057 Am-241 alpha-particles was measured. 4151400100058 (95-AM-242-G,16.02HR) 4151400100059 (95-AM-242-M,141.YR) 141.years was inserted by compiler4151400100060 from Nuclear Wallet Cards 2005. 4151400100061 REL-REF (D,,G.Fioni+,J,NP/A,693,546,2001) 4151400100062 CRITIQUE Of authors. Data of Am-241(n,g)Am-242 c-s of this 4151400100063 experiment are higher then Fioni+ data (696.+-48.)mb 4151400100064 and ENDF/B-VII data 620.8 mb. Most probably, this 4151400100065 difference is conditioned by the fact that the neutrons4151400100066 in IRT MEPhI reactor channels are thermalized 4151400100067 insufficiently. 4151400100068 COMMENT This work was supported by ISTC Project #2405. 4151400100069 HISTORY (20080911C) Compiled at CJD. M.M. 4151400100070 (20111025A) Data values were corrected as given in 4151400100071 report at Conf. 2011SAROV. 4151400100072 (20120214U) Subent 003 was corrected according to the 4151400100073 comment of M.Bossant: 4151400100074 STATUS Shift (TABLE) to the right position . 4151400100075 ENDBIB 73 0 4151400100076 NOCOMMON 0 0 4151400100077 ENDSUBENT 76 0 4151400199999 SUBENT 41514002 20111025 41544151400200001 BIB 4 6 4151400200002 REACTION (95-AM-241(N,G)95-AM-242-G,,SIG,,MXW) 4151400200003 INC-SPECT VEC-25 channel spectrum . 4151400200004 ANALYSIS Basing on results of measuring alpha-spectra from 4151400200005 Am-241 layers. 4151400200006 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400200007 Value confirmed in report of 2011SAROV. 4151400200008 ENDBIB 6 0 4151400200009 NOCOMMON 0 0 4151400200010 DATA 3 1 4151400200011 EN-DUMMY DATA DATA-ERR 4151400200012 EV B B 4151400200013 0.025 836. 32. 4151400200014 ENDDATA 3 0 4151400200015 ENDSUBENT 14 0 4151400299999 SUBENT 41514003 20120214 41564151400300001 BIB 4 13 4151400300002 REACTION (95-AM-242(N,F),,SIG,,MXW) 4151400300003 METHOD Dielectric track detectors underwent etching with 4151400300004 hydrofluoric acid.Counts of tracks caused by fission 4151400300005 fragments were implemented visually by optical 4151400300006 microscope. 4151400300007 ANALYSIS In irradiated layer the nuclei of Am-241, Am-242m, 4151400300008 Am-242g are contained and the accumulation of Cm-242 4151400300009 nuclei takes place.Am-242m fission of Am-241 4151400300010 sub-barrier fission contribute too large to yield of 4151400300011 fission fragments. Statistical analysis of data made 4151400300012 possible to get upper value. 4151400300013 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400300014 Value confirmed in report of 2011SAROV. 4151400300015 ENDBIB 13 0 4151400300016 NOCOMMON 0 0 4151400300017 DATA 2 1 4151400300018 EN-DUMMY DATA-MAX 4151400300019 EV B 4151400300020 0.025 1000. 4151400300021 ENDDATA 3 0 4151400300022 ENDSUBENT 21 0 4151400399999 SUBENT 41514004 20111025 41544151400400001 BIB 3 5 4151400400002 REACTION ((95-AM-242(N,F),,RI)/(94-PU-239(N,F),,RI)) 4151400400003 METHOD Measurement with cadmium jacket. Calibrated layer of 4151400400004 Pu-239 was used as standard. 4151400400005 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400400006 Value confirmed in report of 2011SAROV. 4151400400007 ENDBIB 5 0 4151400400008 NOCOMMON 0 0 4151400400009 DATA 3 1 4151400400010 EN-MIN DATA DATA-ERR 4151400400011 EV NO-DIM NO-DIM 4151400400012 0.5 0.325 0.047 4151400400013 ENDDATA 3 0 4151400400014 ENDSUBENT 13 0 4151400499999 SUBENT 41514005 20111025 41544151400500001 BIB 3 7 4151400500002 REACTION (95-AM-242(N,F),,RI) 4151400500003 MONITOR ((MONIT)94-PU-239(N,F),,RI) 4151400500004 Pu-239 was used as standard. 4151400500005 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400500006 (DEP,41514004) 4151400500007 Value of error was revised in report of 2011SAROV 4151400500008 18. -> 16. 4151400500009 ENDBIB 7 0 4151400500010 NOCOMMON 0 0 4151400500011 DATA 4 1 4151400500012 EN-MIN DATA DATA-ERR MONIT 4151400500013 EV B B B 4151400500014 0.5 97. 16. 299. 4151400500015 ENDDATA 3 0 4151400500016 ENDSUBENT 15 0 4151400599999 SUBENT 41514006 20111025 41544151400600001 BIB 6 9 4151400600002 REACTION (95-AM-241(N,G)95-AM-242-M,,SIG,,MXW) 4151400600003 INC-SPECT VEC-25 channel spectrum . 4151400600004 FACILITY (SPECM) 4151400600005 METHOD (ASEP) 4151400600006 ANALYSIS Isotopic analysis of Am samples by mass-spectrometer 4151400600007 with resolution power 500 . 4151400600008 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400600009 Data value was revised in report of 2011SAROV 4151400600010 148.6+-7.4 -> 151.0+-7.5 4151400600011 ENDBIB 9 0 4151400600012 NOCOMMON 0 0 4151400600013 DATA 3 1 4151400600014 EN-DUMMY DATA DATA-ERR 4151400600015 EV B B 4151400600016 0.025 151.0 7.5 4151400600017 ENDDATA 3 0 4151400600018 ENDSUBENT 17 0 4151400699999 SUBENT 41514007 20111025 41544151400700001 BIB 2 6 4151400700002 REACTION (95-AM-241(N,G)95-AM-242-G/T,,SIG/RAT,,MXW) 4151400700003 STATUS (TABLE) Text of C,2007NICE,1,425,2007, p.427 . 4151400700004 (DEP,41514006) 4151400700005 (DEP,41514002) 4151400700006 Data value was revised in report of 2011SAROV 4151400700007 0.848 -> 0.847. 4151400700008 ENDBIB 6 0 4151400700009 NOCOMMON 0 0 4151400700010 DATA 3 1 4151400700011 EN-DUMMY DATA DATA-ERR 4151400700012 EV NO-DIM NO-DIM 4151400700013 0.025 0.847 0.034 4151400700014 ENDDATA 3 0 4151400700015 ENDSUBENT 14 0 4151400799999 ENDENTRY 7 0 4151499999999