ENTRY C2490 20200303 C192C249000000001 SUBENT C2490001 20200303 C192C249000100001 BIB 9 43 C249000100002 TITLE Helium Ion-Induced Fission of 204Pb at 65, 41, 37 and C249000100003 25 MeV C249000100004 AUTHOR (W.K.Hensley,E.F.Neuzil) C249000100005 REFERENCE (J,JIN,32,1761,1970) C249000100006 #doi:10.1016/0022-1902(70)80580-2 C249000100007 REL-REF (M,C2473001,E.F.Neuzil,J,JIN,27,3,1965) Chemical C249000100008 techniques. C249000100009 INSTITUTE (1USAWWS) C249000100010 SAMPLE (82-PB-204,ENR=0.733) Sample #1. C249000100011 (82-PB-206,ENR=0.1203) C249000100012 (82-PB-207,ENR=0.059) C249000100013 (82-PB-208,ENR=0.0877) C249000100014 (82-PB-204,ENR=0.8924) Sample #2. C249000100015 (82-PB-206,ENR=0.0494) C249000100016 (82-PB-207,ENR=0.0234) C249000100017 (82-PB-208,ENR=0.0348) Enriched isotopes of 204Pb C249000100018 were obtained in the form of Pb(NO3)2 crystals. C249000100019 Targets were prepared in the usual manner by using C249000100020 the lead nitrate crystals as received or in a few C249000100021 cases by using lead powder which was C249000100022 electrochemically reduced from an aqueous solution of C249000100023 the nitrate. The amount of lead in the prepared C249000100024 target usually ranged between 0.5 and 3.0 mg. C249000100025 METHOD (CHSEP,EXTB) Targets of the enriched 204Pb were C249000100026 bombarded with helium ions and the fission fragment C249000100027 cross sections determined radiochemically. The C249000100028 targets were then flown to our laboratories in C249000100029 Bellingham where the fission fragments were separated C249000100030 and purified by the standard radiochemical C249000100031 techniques. The period of time between end of C249000100032 bombardment and counting the purified samples was C249000100033 short enough (~15 hr.) and the fission cross sections C249000100034 high enough that even 2.7 hr 92Sr could be easily C249000100035 identified. Due to the expense of the target material, C249000100036 most of the bombardments were made using the 73 C249000100037 percent enriched isotope (Sample #1). The value C249000100038 measured experimentally, however, was the total C249000100039 fission cross section for all the isotopes present. C249000100040 The value of the fission cross section for 204Pb C249000100041 alone was then resolved by subtracting the C249000100042 contributions from all the "impurity" isotopes. C249000100043 DECAY-DATA (38-SR-92,2.7HR) C249000100044 HISTORY (20200303C) BP C249000100045 ENDBIB 43 0 C249000100046 NOCOMMON 0 0 C249000100047 ENDSUBENT 46 0 C249000199999 SUBENT C2490002 20200303 C192C249000200001 BIB 5 7 C249000200002 REACTION (82-PB-204(A,F)ELEM/MASS,,SIG) C249000200003 FACILITY (CYCLO,1USABRK) The 88 in. cyclotron at the Lawrence C249000200004 Radiation Laboratory, Berkeley, California. C249000200005 FLAG (1.) Rejected for low chemical yield. C249000200006 ERR-ANALYS (DATA-ERR) A probable error of +-20 percent or less C249000200007 unless otherwise noted. C249000200008 STATUS (TABLE) Table 2, page 1763. C249000200009 ENDBIB 7 0 C249000200010 COMMON 2 3 C249000200011 EN DATA-ERR C249000200012 MEV PER-CENT C249000200013 65.0 20.0 C249000200014 ENDCOMMON 3 0 C249000200015 DATA 4 9 C249000200016 ELEMENT MASS DATA FLAG C249000200017 NO-DIM NO-DIM MICRO-B NO-DIM C249000200018 38.0 92.0 1.05 C249000200019 38.0 92.0 1.45 C249000200020 39.0 93.0 2.05 C249000200021 40.0 97.0 0.815 1. C249000200022 42.0 99.0 2.18 C249000200023 46.0 109.0 2.10 C249000200024 46.0 112.0 0.696 C249000200025 47.0 111.0 2.99 C249000200026 47.0 111.0 0.210 C249000200027 ENDDATA 11 0 C249000200028 ENDSUBENT 27 0 C249000299999 SUBENT C2490003 20200303 C192C249000300001 BIB 5 10 C249000300002 REACTION (82-PB-204(A,F)ELEM/MASS,,SIG) C249000300003 FACILITY (CYCLO,1USAWAU) Bombardments at and below 41 MeV took C249000300004 place in the 60in. cyclotron at the University of C249000300005 Washington, Seattle, Washington. C249000300006 FLAG (1.) Consistently low and probably due to poor C249000300007 chemical exchange between inert and radioactive C249000300008 ruthenium carrier. C249000300009 ERR-ANALYS (DATA-ERR) A probable error of +-20 percent or less C249000300010 unless otherwise noted. C249000300011 STATUS (TABLE) Table 2, page 1763. C249000300012 ENDBIB 10 0 C249000300013 COMMON 1 3 C249000300014 EN C249000300015 MEV C249000300016 41.0 C249000300017 ENDCOMMON 3 0 C249000300018 DATA 6 11 C249000300019 ELEMENT MASS DATA DATA-ERR DATA-ERR FLAG C249000300020 NO-DIM NO-DIM MICRO-B MICRO-B PER-CENT NO-DIM C249000300021 32.0 77.0 11.6 20.0 C249000300022 38.0 92.0 45.1 20.0 C249000300023 38.0 92.0 31.8 20.0 C249000300024 39.0 93.0 61.1 1.0 C249000300025 40.0 97.0 87.0 20.0 C249000300026 42.0 99.0 92.0 5.0 C249000300027 44.0 105.0 17.4 20.0 1.C249000300028 46.0 109.0 113.0 20.0 C249000300029 46.0 112.0 44.6 20.0 C249000300030 47.0 111.0 65.0 20.0 C249000300031 47.0 111.0 47.5 20.0 C249000300032 ENDDATA 13 0 C249000300033 ENDSUBENT 32 0 C249000399999 SUBENT C2490004 20200303 C192C249000400001 BIB 4 7 C249000400002 REACTION (82-PB-204(A,F)ELEM/MASS,,SIG) C249000400003 FACILITY (CYCLO,1USAWAU) Bombardments at and below 41 MeV took C249000400004 place in the 60in. cyclotron at the University of C249000400005 Washington, Seattle, Washington. C249000400006 ERR-ANALYS (DATA-ERR) A probable error of +-20 percent or less C249000400007 unless otherwise noted. C249000400008 STATUS (TABLE) Table 2, page 1763. C249000400009 ENDBIB 7 0 C249000400010 COMMON 1 3 C249000400011 EN C249000400012 MEV C249000400013 36.7 C249000400014 ENDCOMMON 3 0 C249000400015 DATA 5 9 C249000400016 ELEMENT MASS DATA DATA-ERR DATA-ERR C249000400017 NO-DIM NO-DIM MICRO-B MICRO-B PER-CENT C249000400018 38.0 92.0 1.33 20.0 C249000400019 38.0 92.0 3.31 20.0 C249000400020 39.0 93.0 7.21 20.0 C249000400021 40.0 97.0 16.2 20.0 C249000400022 42.0 99.0 7.1 0.3 C249000400023 46.0 109.0 15.4 20.0 C249000400024 46.0 112.0 3.22 20.0 C249000400025 47.0 111.0 9.05 20.0 C249000400026 47.0 111.0 2.48 20.0 C249000400027 ENDDATA 11 0 C249000400028 ENDSUBENT 27 0 C249000499999 SUBENT C2490005 20200303 C192C249000500001 BIB 4 7 C249000500002 REACTION (82-PB-204(A,F)ELEM/MASS,,SIG) C249000500003 FACILITY (CYCLO,1USAWAU) Bombardments at and below 41 MeV took C249000500004 place in the 60in. cyclotron at the University of C249000500005 Washington, Seattle, Washington. C249000500006 ERR-ANALYS (DATA-ERR) A probable error of +-20 percent or less C249000500007 unless otherwise noted. C249000500008 STATUS (TABLE) Table 2, page 1763. C249000500009 ENDBIB 7 0 C249000500010 COMMON 1 3 C249000500011 EN C249000500012 MEV C249000500013 25.0 C249000500014 ENDCOMMON 3 0 C249000500015 DATA 5 9 C249000500016 ELEMENT MASS DATA DATA-ERR DATA-ERR C249000500017 NO-DIM NO-DIM MICRO-B MICRO-B PER-CENT C249000500018 38.0 92.0 0.24 0.15 C249000500019 38.0 92.0 0.31 0.15 C249000500020 39.0 93.0 1.0 20.0 C249000500021 40.0 97.0 1.1 20.0 C249000500022 42.0 99.0 0.34 0.15 C249000500023 46.0 109.0 0.082 0.015 C249000500024 46.0 112.0 0.030 0.015 C249000500025 47.0 111.0 0.075 0.015 C249000500026 47.0 111.0 0.055 0.015 C249000500027 ENDDATA 11 0 C249000500028 ENDSUBENT 27 0 C249000599999 SUBENT C2490006 20200303 C192C249000600001 BIB 3 9 C249000600002 REACTION (82-PB-204(A,F),,SIG,,,DERIV) C249000600003 ANALYSIS The total fission cross sections were obtained in the C249000600004 usual manner by summing the individually resolved C249000600005 fission fragment cross sections for 204Pb. C249000600006 STATUS (DEP,C2490002) C249000600007 (DEP,C2490003) C249000600008 (DEP,C2490004) C249000600009 (DEP,C2490005) C249000600010 (TABLE) Table 3, page 1766. C249000600011 ENDBIB 9 0 C249000600012 NOCOMMON 0 0 C249000600013 DATA 2 4 C249000600014 EN DATA C249000600015 MEV MICRO-B C249000600016 65.0 47000.0 C249000600017 41.1 1824.0 C249000600018 36.7 320.0 C249000600019 25.3 18.0 C249000600020 ENDDATA 6 0 C249000600021 ENDSUBENT 20 0 C249000699999 ENDENTRY 6 0 C249099999999