ENTRY M0431 20170329 M088M043100000001 SUBENT M0431001 20170329 M088M043100100001 BIB 14 62 M043100100002 TITLE Photofission cross sections of U-238 and U-235 M043100100003 from 5.0 to 8.0 MeV. M043100100004 AUTHOR (R.A.Anderl,M.V.Yester,R.C.Morrison) M043100100005 REFERENCE (J,NP/A,212,221,1973) M043100100006 #doi:10.1016/0375-9474(73)90560-5 M043100100007 INSTITUTE (1USAIOW) M043100100008 FACILITY (REAC,1USAIOW) M043100100009 INC-SOURCE (MPH=(28-NI-0(N,G))) Radiative capture photons are M043100100010 compton scattered from a curved aluminium plate. The M043100100011 energy of scattered photons was easily varied by M043100100012 rotating and bending the scattering plate. M043100100013 SAMPLE the targets of U-238 (enriched to 99.97%, 7.77 M043100100014 mg/cm**2) and U-235 (enriched to 97.68%, 7.25 M043100100015 mg/cm**2) were the cylindrical metal foil targets M043100100016 5.08 cm high and 2.22 cm diameter. M043100100017 METHOD (EXTB) M043100100018 DETECTOR (SOLST) Heavy-ion surface barrier detectors. M043100100019 The experimental yield curves were measured using four M043100100020 detectors were mounted at 45 and 135 degrees with M043100100021 respect to the incident photon beam. M043100100022 PART-DET (FF) M043100100023 ANALYSIS (INTAD,UNFLD,LEAST) The net yield curve was obtained M043100100024 by normalization of the raw yield data followed by M043100100025 background substraction from the total photofission M043100100026 yield. M043100100027 The average photofission cross section was determined M043100100028 by unfolding the beam spectra from the net M043100100029 photofission yield curve using the least-structure M043100100030 method. Applying the appropriate target, counting M043100100031 efficiency, and normalization factors to the average M043100100032 cross section, the absolute cross cross section value M043100100033 were obtained. M043100100034 ERR-ANALYS (DATA-ERR) The errors are the uncertainties due to M043100100035 propagation of the yield point statistical errors M043100100036 through the unfolding equations. The systematic errors M043100100037 were estimated to be about 30%. M043100100038 COMMENT Cross sections extracted from measured yield curves M043100100039 are reported for photofission of U-238 and U-235. M043100100040 The monoenergetic photons were obtained by compton M043100100041 scattering g-rays produced by neutron capture in a M043100100042 nickel plate near the core of the 5 mw ames M043100100043 laboratory research reactor. An unfolding procedure M043100100044 was used to extract the smoothed cross sections from M043100100045 the measured yield curves. In the U-238(g,f) cross M043100100046 section, prominent structure is observed at 6.2 MeV M043100100047 and 7.6 MeV with hints of structure at 5.5 MeV and M043100100048 7.0 MeV. The U-235(g,f) cross section shows M043100100049 pronounced structure at 5.9 MeV, 6.6 MeV, and 7.5 M043100100050 MeV with a hint of structure at 5.4 MeV. M043100100051 HISTORY (19910218C) M043100100052 (20000225A) M043100100053 Reaction line of SUBENT 003 corrected. M043100100054 SUBENT 004 added. M043100100055 DATA-ERR section of SUBENT 001 corrected, COMMON M043100100056 section changed to NOCOMMON, Date format changed. M043100100057 (20010419A) M043100100058 NOSUBENT record for M0431002 was included because M043100100059 SUBENT M0431003 is used in many data bases. M043100100060 (20110119A) Corrected by V.Varlamov: REFERENCE, M043100100061 NOCOMMON, INC-SOURCE, lowercase. M043100100062 (20170329A) Corrected by V.Varlamov: the HISTORY line M043100100063 (20000225A) added, STATUS. M043100100064 ENDBIB 62 0 M043100100065 NOCOMMON 0 0 M043100100066 ENDSUBENT 65 0 M043100199999 NOSUBENT M0431002 20010419 0000M043100200001 SUBENT M0431003 20170329 M088M043100300001 BIB 3 5 M043100300002 REACTION (92-U-235(G,F),,SIG) M043100300003 STATUS (TABLE) Data from Table 1. M043100300004 HISTORY (20000225A) Corrected by V.Varlamov: REACTION. M043100300005 (20170329A) Corrected by V.Varlamov: the HISTORY line M043100300006 (20000225A) added, STATUS. M043100300007 ENDBIB 5 0 M043100300008 NOCOMMON 0 0 M043100300009 DATA 3 31 M043100300010 EN DATA DATA-ERR M043100300011 MEV MB MB M043100300012 5. -0.4 1.9 M043100300013 5.1 .3 1.6 M043100300014 5.2 1.4 1.3 M043100300015 5.3 2.5 1. M043100300016 5.4 3.2 .9 M043100300017 5.5 3.6 1. M043100300018 5.6 3.9 1.1 M043100300019 5.7 4.6 1.3 M043100300020 5.8 6. 1.3 M043100300021 5.9 7.3 1.3 M043100300022 6. 6.9 1.3 M043100300023 6.1 5.1 1.3 M043100300024 6.2 3.4 1.3 M043100300025 6.3 3.4 1.3 M043100300026 6.4 5.4 1.4 M043100300027 6.5 8.1 1.4 M043100300028 6.6 9.5 1.5 M043100300029 6.7 9.4 1.5 M043100300030 6.8 8.6 1.5 M043100300031 6.9 8.1 1.5 M043100300032 7. 9.5 1.5 M043100300033 7.1 12.7 1.5 M043100300034 7.2 17.2 1.5 M043100300035 7.3 22.6 1.5 M043100300036 7.4 26.9 1.5 M043100300037 7.5 28.4 1.5 M043100300038 7.6 27. 1.5 M043100300039 7.7 23.3 1.4 M043100300040 7.8 18.4 1.5 M043100300041 7.9 13.6 1.6 M043100300042 8. 10. 1.8 M043100300043 ENDDATA 33 0 M043100300044 ENDSUBENT 43 0 M043100399999 SUBENT M0431004 20170329 M088M043100400001 BIB 3 5 M043100400002 REACTION (92-U-238(G,F),,SIG) M043100400003 STATUS (TABLE) Data from Table 1. M043100400004 HISTORY (20000225C) M043100400005 (20170329A) Corrected by V.Varlamov: the HISTORY line M043100400006 (20000225C) added. M043100400007 ENDBIB 5 0 M043100400008 NOCOMMON 0 0 M043100400009 DATA 3 31 M043100400010 EN DATA DATA-ERR M043100400011 MEV MB MB M043100400012 5. -0.8 .6 M043100400013 5.1 -0.9 .5 M043100400014 5.2 -0.9 .4 M043100400015 5.3 -0.5 .4 M043100400016 5.4 .2 .5 M043100400017 5.5 .9 .5 M043100400018 5.6 1.2 .6 M043100400019 5.7 1.4 .6 M043100400020 5.8 2.1 .5 M043100400021 5.9 3.2 .5 M043100400022 6. 4.6 .5 M043100400023 6.1 5.4 .6 M043100400024 6.2 5.2 .6 M043100400025 6.3 4.5 .6 M043100400026 6.4 3.6 .6 M043100400027 6.5 3.1 .6 M043100400028 6.6 3.2 .6 M043100400029 6.7 3.7 .6 M043100400030 6.8 4.3 .6 M043100400031 6.9 4.9 .6 M043100400032 7. 5.3 .5 M043100400033 7.1 5.9 .6 M043100400034 7.2 6.6 .6 M043100400035 7.3 7.7 .6 M043100400036 7.4 8.9 .6 M043100400037 7.5 9.5 .6 M043100400038 7.6 9.6 .6 M043100400039 7.7 9.5 .6 M043100400040 7.8 9. .5 M043100400041 7.9 8.2 .5 M043100400042 8. 7.2 .6 M043100400043 ENDDATA 33 0 M043100400044 ENDSUBENT 43 0 M043100499999 ENDENTRY 4 0 M043199999999