ENTRY M0387 20161221 M086M038700000001 SUBENT M0387001 20161221 M086M038700100001 BIB 13 53 M038700100002 TITLE Fission of complex nuclei induced by 52-MeV M038700100003 monochromatic and polarized photons. M038700100004 AUTHOR (O.A.P.Tavares,M.L.Terranova,L.Casano,A.D'angelo, M038700100005 D.Moricciani,C.Schaerf,D.Babusci,B.Girolami, M038700100006 J.B.Martins,E.L.Moreira,J.L.Vieira) M038700100007 INSTITUTE (2ITYFRA,3BZLRIO) M038700100008 REFERENCE (J,PR/C,44,1683,1991) M038700100009 INC-SOURCE (LCS) Scattering of laser light by the high M038700100010 energy electrons circulating in the storage ring M038700100011 ADONE - Compton backscattering. M038700100012 FACILITY (ESTRG,2ITYFRA) Frascati National Laboratories LADON. M038700100013 SAMPLE The target materials consisted of 0.21 - 0.30 M038700100014 mg/cm**2 thin films of Th-232 - O-2, U-nat. - O-3, M038700100015 and 93 % enriched U-235 - O-2 oxides prepared om M038700100016 mica sheets as supports and were contacted with 100 M038700100017 micron thick Makrofol N, Bayer AG, which served as M038700100018 detectors for fission fragments. The total M038700100019 effective numbers of target nuclei for different M038700100020 stacks were 3.4, 8.1, and 1.9 units of 10**18 cm**-2 M038700100021 for Th-232, U-238, and U-235, respectively. M038700100022 METHOD (EXTB,SITA) M038700100023 DETECTOR (TRD) 100 micron thick Macrofol N, Bayer AG, foils M038700100024 and mica foils. M038700100025 ANALYSIS The direct fission fragment track counting. M038700100026 CORRECTION To obtain the final values of the physical quantities M038700100027 and associated errors, the data have been treated by M038700100028 considering the geometry of exposure, statistics, M038700100029 counting and registration efficiencies, and M038700100030 fission-track background. M038700100031 COMMENT Experimental fissility data from photofission M038700100032 reactions of Th-232, U-238, and U-235 muclei at 52 M038700100033 MeV have been obtained using monochromatic and fully M038700100034 polarized photon beams and dielectric fission-track M038700100035 detectors. These data, along with literature data M038700100036 for Np-237, U-235,238, Th-232, Bi-209, Pb-208, and M038700100037 Yb-174 nuclei have been analyzed within the M038700100038 framework of a simple two-step model for M038700100039 photofission reactions, i.e., absorption of the M038700100040 incident photon by a neutron - proton pair followed M038700100041 by an evaporation-fission competition mechanism for M038700100042 excited nucleus. For nuclei in the ta - np region M038700100043 the trend of calculated fissilities clearly shows M038700100044 shell effects in the vicinity of Pb-208. In the case M038700100045 of U-238 the effect of photon polarization on M038700100046 fission direction has also been studied, and M038700100047 isotropy was observed in the fragment azimuthal M038700100048 distribution. M038700100049 HISTORY (19971015C) Data were compiled at the Russia MSU SINP M038700100050 CDFE by V.Varlamov. M038700100051 (20161221A) Corrected by V.Varlamov: dates, REACTION, M038700100052 ERR-ANALYS, STATUS, COMMON, DATA, SUBENTs 003, 004, M038700100053 006, 007, 009, 010 deleted because no dara for EXFOR, M038700100054 lowercase. M038700100055 ENDBIB 53 0 M038700100056 COMMON 2 3 M038700100057 EN EN-RSL-FW M038700100058 MEV PER-CENT M038700100059 52. 10. M038700100060 ENDCOMMON 3 0 M038700100061 ENDSUBENT 60 0 M038700199999 SUBENT M0387002 20161221 M086M038700200001 BIB 4 5 M038700200002 REACTION (90-TH-232(G,F),,SIG) M038700200003 ERR-ANALYS (ERR-S) Statistical errors are given. M038700200004 STATUS (TABLE) Data from Table 1. M038700200005 HISTORY (20161221A) Corrected by V.Varlamov: dates, REACTION, M038700200006 STATUS, DATA substituted. M038700200007 ENDBIB 5 0 M038700200008 NOCOMMON 0 0 M038700200009 DATA 2 1 M038700200010 DATA ERR-S M038700200011 MB MB M038700200012 6. 1. M038700200013 ENDDATA 3 0 M038700200014 ENDSUBENT 13 0 M038700299999 NOSUBENT M0387003 20161221 M086M038700300001 NOSUBENT M0387004 20161221 M086M038700400001 SUBENT M0387005 20161221 M086M038700500001 BIB 4 5 M038700500002 REACTION (92-U-235(G,F),,SIG) M038700500003 ERR-ANALYS (ERR-S) Statistical errors are given. M038700500004 STATUS (TABLE) Data from Table 1. M038700500005 HISTORY (20161221A) Corrected by V.Varlamov: dates, REACTION, M038700500006 STATUS, DATA. M038700500007 ENDBIB 5 0 M038700500008 NOCOMMON 0 0 M038700500009 DATA 2 1 M038700500010 DATA ERR-S M038700500011 MB MB M038700500012 16. 2. M038700500013 ENDDATA 3 0 M038700500014 ENDSUBENT 13 0 M038700599999 NOSUBENT M0387006 20161221 M086M038700600001 NOSUBENT M0387007 20161221 M086M038700700001 SUBENT M0387008 20161221 M086M038700800001 BIB 4 5 M038700800002 REACTION (92-U-238(G,F),,SIG) M038700800003 ERR-ANALYS (ERR-S) Statistical errors are given. M038700800004 STATUS (TABLE) Data from Table 1. M038700800005 HISTORY (20161221A) Corrected by V.Varlamov: dates, REACTION, M038700800006 STATUS, DATA substituted. M038700800007 ENDBIB 5 0 M038700800008 NOCOMMON 0 0 M038700800009 DATA 2 1 M038700800010 DATA ERR-S M038700800011 MB MB M038700800012 10. 1. M038700800013 ENDDATA 3 0 M038700800014 ENDSUBENT 13 0 M038700899999 NOSUBENT M0387009 20161221 M086M038700900001 NOSUBENT M0387010 20161221 M086M038701000001 ENDENTRY 10 0 M038799999999