ENTRY 41758 20230828 4175800000001 SUBENT 41758001 20230828 20231127 4175800100001 BIB 12 58 4175800100002 TITLE Structure of the prompt neutron multiplicity 4175800100003 distribution in the spontaneous fission of 256Rf 4175800100004 AUTHOR (A.V.Isaev,R.S.Mukhin,A.V.Andreev,Z.Asfari, 4175800100005 M.L.Chelnokov,V.I.Chepigin,H.M.Devaraja,O.Dorvaux, 4175800100006 B.Gall,K.Hauschild,I.N.Izosimov,A.A.Kuznetsova, 4175800100007 A.Lopez-Martens,O.N.Malyshev,A.G.Popeko,Yu.A.Popov, 4175800100008 A.Rahmatinejad,B.Sailaubekov,T.M.Shneidman,E.A.Sokol, 4175800100009 A.I.Svirikhin,M.S.Tezekbayeva,A.V.Yeremin, 4175800100010 N.I.Zamyatin) 4175800100011 INSTITUTE (4ZZZDUB) A.V.Isaev,R.S.Mukhin,A.V.Andreev, 4175800100012 M.L.Chelnokov,V.I.Chepigin,H.M.Devaraja,I.N.Izosimov, 4175800100013 A.A.Kuznetsova,O.N.Malyshev,A.G.Popeko,Yu.A.Popov, 4175800100014 A.Rahmatinejad,B.Sailaubekov,T.M.Shneidman,E.A.Sokol, 4175800100015 A.I.Svirikhin,M.S.Tezekbayeva,A.V.Yeremin, 4175800100016 N.I.Zamyatin 4175800100017 (2FR STR)Z.Asfari,O.Dorvaux,B.Gall 4175800100018 (2FR PAR)K.Hauschild, A.Lopez-Martens 4175800100019 (4RUSDBU) O.N.Malyshev,A.G.Popeko,Yu.A.Popov, 4175800100020 A.I.Svirikhin,A.V.Yeremin 4175800100021 (4KASKAZ) B.Sailaubekov,M.S.Tezekbayeva 4175800100022 (4KASATN) B.Sailaubekov, 4175800100023 (4RUSRUS) Kazan Federal University, Kazan, Russia. 4175800100024 T.M.Shneidman 4175800100025 REFERENCE (J,PL/B,843,138008,2023) 4175800100026 #doi:10.1016/j.physletb.2023.138008 4175800100027 FACILITY (CYCLO,4ZZZDUB) U-400 cyclotron 4175800100028 SHELS velocity filter = modernized 4175800100029 VASSILISSA electrostatic separator. 4175800100030 SAMPLE 208PbS (thickness 350 microg/cm2, Pb-208 isotope 4175800100031 enrichment > 99 %) was irradiated with a beam (up to 4175800100032 237+-3 MeV energy) of charged 50-Ti ions. 4175800100033 The total number of beam ions that passed through the 4175800100034 target and then stopped in a faraday cup was about 4175800100035 2.8*10**18. 4175800100036 Rf-256 nuclei were separated by SHELS filter. 4175800100037 DETECTOR (SISD,HE3SP) 54 He-3 neutron detectors placed around 4175800100038 an assembly of Si detectors consisting of a 48x48-strip4175800100039 focal-plane detector and 4 tunnel 16-strip detectors 4175800100040 for fission fragments and alpha-particle registration. 4175800100041 The neutron detector efficiency measured with a 248Cm 4175800100042 source was (45 +- 1)%. 4175800100043 Average neutron life-time in the assembly is 4175800100044 (23+-1) microsec . 4175800100045 DECAY-DATA (104-RF-256,6.7E-3SEC) 6.7+-0.2 msec, measured. 4175800100046 METHOD Fission fragments from Rf-256 spontaneous fission were4175800100047 searched for the time interval (0 - 62) msec (~10*T1/2)4175800100048 following the registration of the implanted reaction 4175800100049 products. 4175800100050 Total number of 2605 prompt neutrons in correlation 4175800100051 with 1345 256Rf spontaneous fission events were 4175800100052 registered. 4175800100053 Neutron signals were separated from gamma-quanta 4175800100054 signals by setting the thresholds of discriminators. 4175800100055 CORRECTION Background neutron counting rate was ~100 neutrons/s 4175800100056 inside the detector. 4175800100057 ADD-RES (DECAY) the alpha decay branching ratio was found to be4175800100058 0.003 +0.005 -0.003. 4175800100059 HISTORY (20230828C) M.M. 4175800100060 ENDBIB 58 0 4175800100061 NOCOMMON 0 0 4175800100062 ENDSUBENT 61 0 4175800199999 SUBENT 41758002 20230828 20231127 4175800200001 BIB 4 6 4175800200002 REACTION (104-RF-256(0,F),PR,NU) 4175800200003 MISC-COL (MISC) Variance of neutron distribution 4175800200004 ERR-ANALYS (ERR-S) Statistical uncertainty. 4175800200005 STATUS (TABLE,,A.V.Isaev+,J,PL/B,843,138008,2023) 4175800200006 Text in chapter 3.Results. 4175800200007 (DEP,41758003) Prompt neutron distribution. 4175800200008 ENDBIB 6 0 4175800200009 NOCOMMON 0 0 4175800200010 DATA 3 1 4175800200011 DATA ERR-S MISC 4175800200012 PRT/FIS PRT/FIS SEE TEXT 4175800200013 4.30 0.17 3.2 4175800200014 ENDDATA 3 0 4175800200015 ENDSUBENT 14 0 4175800299999 SUBENT 41758003 20230828 20231127 4175800300001 BIB 4 10 4175800300002 REACTION (104-RF-256(0,F),PR/NUM,NU) 4175800300003 MISC-COL (MISC1) Distribution of multiplicity of detected prompt4175800300004 neutrons, normalized to 1. 4175800300005 (MISC2) Number of observed spontaneous fission events. 4175800300006 ERR-ANALYS (ERR-S) Statistical uncertainty. 4175800300007 (MISC1-ERR) Statistical uncertainty. 4175800300008 For PART-OUT = 7 and 8 the value is < 0.001 in 4175800300009 the Table 1. 4175800300010 STATUS (TABLE,,A.V.Isaev+,J,PL/B,843,138008,2023) 4175800300011 Table 1 . 4175800300012 ENDBIB 10 0 4175800300013 NOCOMMON 0 0 4175800300014 DATA 6 9 4175800300015 PART-OUT DATA ERR-S MISC1 MISC1-ERR MISC2 4175800300016 NO-DIM NO-DIM NO-DIM NO-DIM NO-DIM SEE TEXT 4175800300017 0. 0.042 0.014 0.148 0.010 199. 4175800300018 1. 0.062 0.018 0.259 0.014 348. 4175800300019 2. 0.062 0.021 0.255 0.010 343. 4175800300020 3. 0.102 0.021 0.215 0.007 290. 4175800300021 4. 0.192 0.022 0.096 0.004 129. 4175800300022 5. 0.253 0.022 0.024 0.002 32. 4175800300023 6. 0.205 0.019 0.002 0.001 3. 4175800300024 7. 0.082 0.018 0.001 1. 4175800300025 8. 0. 0.014 0. 0. 4175800300026 ENDDATA 11 0 4175800300027 ENDSUBENT 26 0 4175800399999 ENDENTRY 3 0 4175899999999