ENTRY M0432 20161223 M086M043200000001 SUBENT M0432001 20161223 M086M043200100001 BIB 15 49 M043200100002 TITLE Photofission cross sections of Th-232 and U-236 M043200100003 from threshold to 8 MeV. M043200100004 AUTHOR (M.V.Yester,R.A.Anderl,R.C.Morrison) M043200100005 REFERENCE (J,NP/A,206,593,1973) M043200100006 INSTITUTE (1USAIOW) M043200100007 FACILITY (REAC,1USAIOW) M043200100008 INC-SOURCE (MPH=(28-NI-0(N,G))) M043200100009 A variable-energy beam of monoenergetic photons was M043200100010 obtained by Compton scattering the primary beam of M043200100011 radiative capture photons from an aluminium plate M043200100012 with a continuously variable radius of curvature. M043200100013 SAMPLE The target of Th-232 consisted of 156.4 mg of M043200100014 material (4.4 mg/cm**2) and was assayed at 100% M043200100015 Th-232. The U-236 target consisted of 317 mg of M043200100016 material (8.9 mg/cm**2) assayed at 89.38% U-236, M043200100017 9.20% U-235, 1.306% U-238, and 0.116% U-234. M043200100018 DETECTOR (SOLST) Heavy-ion silicon surface barrier detectors. M043200100019 Each of four detectors used was positioned on the M043200100020 rod located at 45 degrees with respect to the M043200100021 gamma-ray beam. M043200100022 PART-DET (FF) M043200100023 METHOD (EXTB) The yield points were formed from the sum of M043200100024 events in the four detectors. M043200100025 Compton scattering facility used provides a photon M043200100026 beam with a continuous energy distribution, rather M043200100027 than one discrete energy. hence, the photofission M043200100028 cross section could not be obtained directly, but M043200100029 were extracted from a measurement of fission M043200100030 yield as a function of end-point energy. M043200100031 ANALYSIS (UNFLD,LEAST) The unfolding procedure was the M043200100032 modification of least structure method of Cook: the M043200100033 cook's routine was developed for use not M043200100034 bremsstrahlung spectrum, but the specific spectrum M043200100035 of Compton scattered monoenergetic photons. M043200100036 REL-REF (N,,B.C.Cook,J,NIM,24,256,1963) M043200100037 Unfolding 'least-structure' method. M043200100038 ERR-ANALYS (ERR-S) The errors are statistical. M043200100039 (ERR-SYS) The systematic errors were estimated as to M043200100040 be about 30%. M043200100041 COMMENT Measurements of the photofission cross sections of M043200100042 Th-232 and U-236 for an energy range of 5.0 to 8.0 M043200100043 MeV are reported. The compton scattering facility at M043200100044 ames laboratory research reactor was used for these M043200100045 measurements. Resonance structure at g-ray energies M043200100046 of 6.3 and 7.6 MeV is observed in Th-232 and at 5.3, M043200100047 6.0, 6.5, and 7.5 MeV in U-236. M043200100048 HISTORY (19910218C) M043200100049 (20161223A) Corrected by V.Varlamov: dates, ANALYSIS, M043200100050 ERR-ANALYS, STATUS, REL-REF, COMMON, lowercase. M043200100051 ENDBIB 49 0 M043200100052 COMMON 1 3 M043200100053 ERR-SYS M043200100054 PER-CENT M043200100055 30. M043200100056 ENDCOMMON 3 0 M043200100057 ENDSUBENT 56 0 M043200199999 SUBENT M0432002 20161223 M086M043200200001 BIB 3 4 M043200200002 REACTION (92-U-236(G,F),,SIG) M043200200003 STATUS (TABLE) Data from Table 1. M043200200004 HISTORY (20161223A) Corrected by V.Varlamov: STATUS, M043200200005 ERR-S. M043200200006 ENDBIB 4 0 M043200200007 NOCOMMON 0 0 M043200200008 DATA 3 31 M043200200009 EN DATA ERR-S M043200200010 MEV MB MB M043200200011 5. -2.6 1.3 M043200200012 5.1 -2. 1.1 M043200200013 5.2 -1.1 .8 M043200200014 5.3 -0.1 .7 M043200200015 5.4 .2 .7 M043200200016 5.5 .7 .8 M043200200017 5.6 1.3 .9 M043200200018 5.7 2.1 1.0 M043200200019 5.8 3.2 1.0 M043200200020 5.9 4.2 1.0 M043200200021 6. 4.7 1.0 M043200200022 6.1 4.9 1.0 M043200200023 6.2 4.9 1.0 M043200200024 6.3 5. 1. M043200200025 6.4 5.3 1.0 M043200200026 6.5 5.7 1.1 M043200200027 6.6 5.7 1.1 M043200200028 6.7 5.5 1.1 M043200200029 6.8 5.3 1.1 M043200200030 6.9 5.0 1.1 M043200200031 7. 5.4 1.1 M043200200032 7.1 6.4 1.1 M043200200033 7.2 8.0 1.1 M043200200034 7.3 10.1 1.1 M043200200035 7.4 11.9 1.1 M043200200036 7.5 12.6 1.1 M043200200037 7.6 12.6 1.1 M043200200038 7.7 12.1 1.1 M043200200039 7.8 11.5 1.1 M043200200040 7.9 10.7 1.1 M043200200041 8. 9.8 1.3 M043200200042 ENDDATA 33 0 M043200200043 ENDSUBENT 42 0 M043200299999 SUBENT M0432003 20161223 M086M043200300001 BIB 3 4 M043200300002 REACTION (90-TH-232(G,F),,SIG) M043200300003 STATUS (TABLE) Data from Table 1. M043200300004 HISTORY (20161223A) Corrected by V.Varlamov: STATUS, M043200300005 ERR-S. M043200300006 ENDBIB 4 0 M043200300007 NOCOMMON 0 0 M043200300008 DATA 3 31 M043200300009 EN DATA ERR-S M043200300010 MEV MB MB M043200300011 5. -0.6 .6 M043200300012 5.1 -0.6 .5 M043200300013 5.2 -0.7 .3 M043200300014 5.3 -0.8 .3 M043200300015 5.4 -0.9 .4 M043200300016 5.5 -0.6 .4 M043200300017 5.6 .1 .5 M043200300018 5.7 .9 .5 M043200300019 5.8 1.7 .5 M043200300020 5.9 2.9 .5 M043200300021 6. 4.5 .5 M043200300022 6.1 6.2 .5 M043200300023 6.2 7.6 .5 M043200300024 6.3 8.3 .5 M043200300025 6.4 8.2 .5 M043200300026 6.5 7.5 .5 M043200300027 6.6 6.4 .5 M043200300028 6.7 5.2 .5 M043200300029 6.8 4.2 .5 M043200300030 6.9 3.6 .5 M043200300031 7. 3.4 .5 M043200300032 7.1 3.5 .5 M043200300033 7.2 3.9 .5 M043200300034 7.3 4.3 .5 M043200300035 7.4 4.7 .5 M043200300036 7.5 5.1 .5 M043200300037 7.6 5.1 .5 M043200300038 7.7 4.7 .5 M043200300039 7.8 3.9 .5 M043200300040 7.9 3.1 .5 M043200300041 8. 2.4 .6 M043200300042 ENDDATA 33 0 M043200300043 ENDSUBENT 42 0 M043200399999 ENDENTRY 3 0 M043299999999