ENTRY 23217 20151013 22452321700000001 SUBENT 23217001 20151013 22452321700100001 BIB 18 58 2321700100002 TITLE Measurement of the neutron-induced fission cross 2321700100003 sections of 209Bi at 45 and 73 MeV. 2321700100004 AUTHOR (V.P.Eismont, A.V.Kireev,I.V.Ryzhov,G.A.Tutin, H.Conde,2321700100005 K.Elmgren, S.Hultqvist) 2321700100006 REFERENCE (C,96KALMAR,2,618,1996) 2321700100007 INSTITUTE (4RUSRI) V.P.Eismont,A.V.Kireev,I.V.Ryzhov,G.A.Tutin. 2321700100008 (2SWDUPP) H.Conde,K.Elmgren,S.Hultqvist. 2321700100009 FACILITY (CYCLO,2SWDUPP) TSL cyclotron, Uppsala 2321700100010 INC-SOURCE (P-LI7) 8 mm Li-7 target was bombarded by 49.1 and 2321700100011 76.4 MeV protons. 4-6 ns wide pulses separated by 2321700100012 60-75 ns. Neutron beam diameter was about 10 cm in 2321700100013 the target position. 2321700100014 INC-SPECT Neutron flux was of order 10**6 1/sec within a solid 2321700100015 angle 60 microsr with proton current up to 3 microAmp. 2321700100016 METHOD (TOF) Neutron flight path about 11 m. 2321700100017 (PHD) 2321700100018 DETECTOR (IOCH) Twin ionization chamber with Frisch grids. 2321700100019 100% efficiency. The intrinsic time resolution of the 2321700100020 ionization chamber was about 4.5 ns (FWHM). 2321700100021 Thickness of targets (mg/cm**2) : 2321700100022 En,MeV U(3)O(8) Bi 2321700100023 45. 0.425 0.85 2321700100024 73. 1.31 1.65 2321700100025 The energy calibration of the chamber was made using 2321700100026 energies of U-234 and U-238 alpha-particles. 2321700100027 PART-DET (FF) Fission fragments were detected. 2321700100028 MONITOR (92-U-238(N,F),,SIG) 2321700100029 MONIT-REF (14016001,P.W.Lisowski+,S,NEANDC-305,177,1991) 2321700100030 SAMPLE Nat-U(3)O(8) , metallic Bi were located back to back. 2321700100031 Non-uniformity of the layers was within 15 %. Targets 2321700100032 diameter 78 mm. 2321700100033 ANALYSIS The distributions of number of measured events for 2321700100034 Bi-209 and U-238 targets versus TOF of the incident 2321700100035 neutrons were analyzed off-line with an energy 2321700100036 threshold of 30 MeV. 2321700100037 CORRECTION For the loss of events due to the 30 MeV threshold 2321700100038 fixed for the TOF spectra. 2321700100039 For the target thickness. 2321700100040 For linear momentum transferred to the compound nucleus2321700100041 and anisotropy of fission fragments - estimated using 2321700100042 the proton-induced fission data. 2321700100043 ERR-ANALYS (ERR-S) Statistical error. 2321700100044 Uncertainty components: 2321700100045 (ERR-1) Mass of targets. 2321700100046 (ERR-2) Target thickness correction. 2321700100047 (ERR-3) TOF spectrum decomposition. 2321700100048 (ERR-4) Energy spectrum extrapolation. 2321700100049 (ERR-5,,0.5) Linear momentum transfer correction- 2321700100050 for 73 MeV - 0.5%, for 45 MeV <0.5%. 2321700100051 (ERR-T) Total relative uncertainty. 2321700100052 (DATA-ERR) Not explained, probably absolute total. 2321700100053 STATUS (COREL,22903001) MFGIC - multi-section Frisch-gridded 2321700100054 ionization chamber measurement (further improvement of 2321700100055 detector, published in 2004-2006) 2321700100056 (COREL,22646001) TFBC - thin film breakdown counters. 2321700100057 HISTORY (20131212C) M.M. 2321700100058 (20151013A) SD: In Subent 002 SF1 changed in REACTION 2321700100059 denominator following remark from B.Marcinkevicius. 2321700100060 ENDBIB 58 0 2321700100061 COMMON 3 3 2321700100062 ERR-S ERR-1 ERR-2 2321700100063 PER-CENT PER-CENT PER-CENT 2321700100064 7. 0.5 0.5 2321700100065 ENDCOMMON 3 0 2321700100066 ENDSUBENT 65 0 2321700199999 SUBENT 23217002 20151013 22452321700200001 BIB 4 8 2321700200002 REACTION ((83-BI-209(N,F),,SIG)/(92-U-238(N,F),,SIG)) 2321700200003 REL-REF (A,22646002,V.P.Eismont+,J,PR/C,53,2911,1996) 2321700200004 At 73 MeV agree with value (9.7+-0.9)*10**-3 . 2321700200005 (A,22646002,V.P.Eismont+,C,96KALMAR,2,606,1996) 2321700200006 At 45 MeV agree with value (1.18+-0.15)*10**-3 . 2321700200007 STATUS (TABLE) Table 2 of C,96KALMAR,2,618,1996 . 2321700200008 HISTORY (20151013A) SD: SF1=U-235 -> U-238 in REACTION 2321700200009 denominator following Tbl.2 of 96KALMAR,2,618,1996. 2321700200010 ENDBIB 8 0 2321700200011 NOCOMMON 0 0 2321700200012 DATA 6 2 2321700200013 EN DATA DATA-ERR ERR-T ERR-3 ERR-4 2321700200014 MEV NO-DIM NO-DIM PER-CENT PER-CENT PER-CENT 2321700200015 45. 1.07E-3 0.08E-3 7.4 2. 1. 2321700200016 73. 9.1E-3 1.2E-3 12.8 8. 7. 2321700200017 ENDDATA 4 0 2321700200018 ENDSUBENT 17 0 2321700299999 SUBENT 23217003 20131212 22392321700300001 BIB 5 6 2321700300002 REACTION (83-BI-209(N,F),,SIG) 2321700300003 MONITOR (92-U-238(N,F),,SIG) 2321700300004 MONIT-REF (14016001,P.W.Lisowski+,S,NEANDC-305,177,1991) 2321700300005 ERR-ANALYS (MONIT-ERR) U-238 standard cross section 2321700300006 STATUS (TABLE) Table 2 of C,96KALMAR,2,618,1996 . 2321700300007 (DEP,23172002) Measured ratio. 2321700300008 ENDBIB 6 0 2321700300009 COMMON 1 3 2321700300010 MONIT-ERR 2321700300011 PER-CENT 2321700300012 5. 2321700300013 ENDCOMMON 3 0 2321700300014 DATA 6 2 2321700300015 EN DATA DATA-ERR ERR-T ERR-3 ERR-4 2321700300016 MEV MB MB PER-CENT PER-CENT PER-CENT 2321700300017 45. 1.80 0.16 8.9 2. 1. 2321700300018 73. 13.9 1.9 13.7 8. 7. 2321700300019 ENDDATA 4 0 2321700300020 ENDSUBENT 19 0 2321700399999 ENDENTRY 3 0 2321799999999