ENTRY 14642 20211107 14891464200000001 SUBENT 14642001 20211107 14891464200100001 BIB 11 54 1464200100002 TITLE Spectrum of gamma rays in the 8- to 20-MeV range from 1464200100003 252Cf spontaneous fission 1464200100004 AUTHOR (F.S.Dietrich,J.C.Browne,W.J.O'Connell,M.J.Kay) 1464200100005 INSTITUTE (1USALRL) 1464200100006 REFERENCE (J,PR/C,10,795,1974) 1464200100007 #doi:10.1103/PhysRevC.10.795 1464200100008 METHOD (TOF) Time-of-flight techniques was used to eliminate 1464200100009 the effects of fission neutrons. 1464200100010 DETECTOR (NAICR) The gamma detector was a 25.4 cm diam x 25.4 cm1464200100011 long NaI scintillator surrounded by a 15.24 cm thick 1464200100012 NE102 plastic anticoincidence shield on the sides and 1464200100013 a 3.81 cm thick shield in front. 1464200100014 The energy calibration was accomplished by using a PuBe1464200100015 neutron source, which provides gamma peaks of 2.23 MeV 1464200100016 from neutron capture in the plastic shield, 4.43 MeV 1464200100017 from 9Be(alpha,n)12C*, and 6.797 MeV from full-energy 1464200100018 capture of slow neutrons on 127I. The calibration was 1464200100019 linearly extrapolated to the 10- to 20-MeV region. 1464200100020 SAMPLE The 252Cf source was evaporated onto a 5-cm2 nickel 1464200100021 foil and placed in an ionization chamber filled with 1464200100022 methane (CH4). 1464200100023 ANALYSIS To determine the absolute yield, the accepted gamma 1464200100024 pulse-height spectra were unfolded by an iterative 1464200100025 technique using response functions for discrete gamma 1464200100026 lines measured with the identical geometries used in 1464200100027 the 252Cf source runs. Gamma rays of energy 14.0 and 1464200100028 16.8 MeV were produced by the 15N(p,gamma)160 1464200100029 reaction at incident proton energies 2 and 5 MeV 1464200100030 furnished by the Lawrence Livermore Laboratory tandem 1464200100031 accelerator; 4.43-MeV gamma rays were observed from 1464200100032 the 15N(p,alpha)12C* reaction in the same series of 1464200100033 runs. The line shapes were parametrized with a 1464200100034 functional form which was also used to extrapolate 1464200100035 them to low energies. For each geometry, line shapes 1464200100036 at other energies mere determined by linearly 1464200100037 interpolating or extrapolating the measured line 1464200100038 shape parameters. Uncertainty in the low-energy 1464200100039 extrapolation of the line shapes contributes an 1464200100040 uncertainty of +/- 15% to the final absolute scale. 1464200100041 The counting statistics in the original spectra are 1464200100042 amplified by the unfolding procedure; these 1464200100043 variations mere reduced by Gaussian smoothing with 1464200100044 FTHM in the range 2-4%. 1464200100045 CORRECTION The absolute yield mas corrected for a 12% absorption 1464200100046 of gamma rays in the front 6LiH shield, the front 1464200100047 plastic, and the NaI housing materials, and for the 1464200100048 gamma rays that pass through the NaI without 1464200100049 interaction (calculated as 3% for the two small solid 1464200100050 angles). For the large solid angle, the correction for 1464200100051 gamma rays not interacting in the NaI was found by 1464200100052 comparing the observed yields of the 15N(p,gamma)16O 1464200100053 gamma rays with the different solid angles. 1464200100054 ERR-ANALYS No information on uncertainties. 1464200100055 HISTORY (20210810C) OG 1464200100056 ENDBIB 54 0 1464200100057 NOCOMMON 0 0 1464200100058 ENDSUBENT 57 0 1464200199999 SUBENT 14642002 20210814 14891464200200001 BIB 2 4 1464200200002 REACTION (98-CF-252(0,F)0-G-0,PR,FY/DE,,MSC) 1464200200003 For solid angle = 0.0179 sr 1464200200004 STATUS (CURVE) Fig.8 (p.798) in Phys.Rev/C,10,795,1974 was 1464200200005 digitized by GSYS2.4.7. 1464200200006 ENDBIB 4 0 1464200200007 NOCOMMON 0 0 1464200200008 DATA 2 54 1464200200009 E DATA 1464200200010 MEV PT/FIS/MEV 1464200200011 7.111 2.048E+04 1464200200012 7.246 1.291E+04 1464200200013 7.500 7.224E+03 1464200200014 7.664 5.176E+03 1464200200015 7.874 4.354E+03 1464200200016 8.017 2.239E+03 1464200200017 8.191 2.008E+03 1464200200018 8.383 1.534E+03 1464200200019 8.602 1.250E+03 1464200200020 8.796 1.316E+03 1464200200021 8.940 8.846E+02 1464200200022 9.096 7.687E+02 1464200200023 9.289 8.097E+02 1464200200024 9.482 7.829E+02 1464200200025 9.645 5.149E+02 1464200200026 9.819 4.620E+02 1464200200027 10.003 4.280E+02 1464200200028 10.306 3.754E+02 1464200200029 10.583 4.896E+02 1464200200030 10.734 1.989E+02 1464200200031 10.945 1.882E+02 1464200200032 11.077 3.317E+02 1464200200033 11.313 1.857E+02 1464200200034 11.468 1.562E+02 1464200200035 11.675 3.301E+02 1464200200036 11.858 3.091E+02 1464200200037 12.194 1.441E+02 1464200200038 12.406 1.653E+02 1464200200039 12.563 1.651E+02 1464200200040 12.934 2.753E+02 1464200200041 13.131 1.142E+02 1464200200042 13.347 5.623E+01 1464200200043 13.459 7.187E+01 1464200200044 13.682 1.162E+02 1464200200045 13.857 1.123E+02 1464200200046 14.019 6.093E+01 1464200200047 14.227 3.717E+01 1464200200048 14.411 3.334E+01 1464200200049 14.618 1.642E+01 1464200200050 14.772 1.091E+01 1464200200051 14.924 2.382E+01 1464200200052 15.118 3.076E+01 1464200200053 15.330 2.974E+01 1464200200054 15.526 5.237E+01 1464200200055 15.703 7.608E+01 1464200200056 15.864 3.870E+01 1464200200057 16.052 1.474E+01 1464200200058 16.260 3.816E+01 1464200200059 16.406 6.653E+00 1464200200060 16.624 4.374E+00 1464200200061 16.810 1.247E+00 1464200200062 16.952 1.246E+01 1464200200063 17.147 1.791E+01 1464200200064 17.338 1.256E+01 1464200200065 ENDDATA 56 0 1464200200066 ENDSUBENT 65 0 1464200299999 SUBENT 14642003 20210814 14891464200300001 BIB 2 4 1464200300002 REACTION (98-CF-252(0,F)0-G-0,PR,FY/DE,,MSC) 1464200300003 For solid angle = 0.0365 sr 1464200300004 STATUS (CURVE) Fig.8 (p.798) in Phys.Rev/C,10,795,1974 was 1464200300005 digitized by GSYS2.4.7. 1464200300006 ENDBIB 4 0 1464200300007 NOCOMMON 0 0 1464200300008 DATA 2 55 1464200300009 E DATA 1464200300010 MEV PT/FIS/MEV 1464200300011 7.128 1.600E+04 1464200300012 7.319 1.197E+04 1464200300013 7.501 8.303E+03 1464200300014 7.674 5.886E+03 1464200300015 7.864 3.829E+03 1464200300016 8.000 2.629E+03 1464200300017 8.229 2.283E+03 1464200300018 8.384 1.745E+03 1464200300019 8.602 1.099E+03 1464200300020 8.767 1.018E+03 1464200300021 8.960 9.951E+02 1464200300022 9.095 6.760E+02 1464200300023 9.290 9.109E+02 1464200300024 9.482 6.959E+02 1464200300025 9.654 4.626E+02 1464200300026 9.866 5.481E+02 1464200300027 10.013 4.814E+02 1464200300028 10.196 4.050E+02 1464200300029 10.353 4.801E+02 1464200300030 10.500 4.847E+02 1464200300031 10.582 4.260E+02 1464200300032 10.754 2.684E+02 1464200300033 10.956 2.460E+02 1464200300034 11.113 2.676E+02 1464200300035 11.316 3.104E+02 1464200300036 11.482 3.601E+02 1464200300037 11.664 2.553E+02 1464200300038 12.030 1.826E+02 1464200300039 12.223 1.692E+02 1464200300040 12.395 1.174E+02 1464200300041 12.566 6.504E+01 1464200300042 12.762 9.446E+01 1464200300043 13.124 1.849E+02 1464200300044 13.318 1.907E+02 1464200300045 13.473 1.521E+02 1464200300046 13.661 7.410E+01 1464200300047 13.866 2.205E+01 1464200300048 14.020 3.491E+00 1464200300049 14.229 1.050E+01 1464200300050 14.394 4.598E+01 1464200300051 14.591 8.729E+01 1464200300052 14.774 7.584E+01 1464200300053 14.946 4.529E+01 1464200300054 15.102 4.721E+01 1464200300055 15.334 6.293E+01 1464200300056 15.516 4.413E+01 1464200300057 15.666 1.593E+01 1464200300058 15.865 9.313E+00 1464200300059 16.249 2.952E+01 1464200300060 16.394 2.184E+01 1464200300061 16.601 1.019E+01 1464200300062 16.810 5.769E+00 1464200300063 16.962 3.096E+00 1464200300064 17.151 1.508E+00 1464200300065 17.305 2.414E+01 1464200300066 ENDDATA 57 0 1464200300067 ENDSUBENT 66 0 1464200399999 SUBENT 14642004 20210814 14891464200400001 BIB 2 4 1464200400002 REACTION (98-CF-252(0,F)0-G-0,PR,FY/DE,,MSC) 1464200400003 For solid angle = 0.251 sr 1464200400004 STATUS (CURVE) Fig.8 (p.798) in Phys.Rev/C,10,795,1974 was 1464200400005 digitized by GSYS2.4.7. 1464200400006 ENDBIB 4 0 1464200400007 NOCOMMON 0 0 1464200400008 DATA 2 42 1464200400009 E DATA 1464200400010 MEV PT/FIS/MEV 1464200400011 7.038 2.380E+04 1464200400012 7.293 1.598E+04 1464200400013 7.595 1.194E+04 1464200400014 7.904 6.898E+03 1464200400015 8.110 2.655E+03 1464200400016 8.504 2.183E+03 1464200400017 8.826 2.224E+03 1464200400018 9.127 1.327E+03 1464200400019 9.429 1.103E+03 1464200400020 9.712 7.731E+02 1464200400021 9.792 4.772E+02 1464200400022 10.006 7.880E+02 1464200400023 10.317 5.824E+02 1464200400024 10.608 3.329E+02 1464200400025 10.894 3.818E+02 1464200400026 11.180 4.062E+02 1464200400027 11.489 2.272E+02 1464200400028 11.781 1.626E+02 1464200400029 12.075 1.676E+02 1464200400030 12.390 2.185E+02 1464200400031 12.655 1.856E+02 1464200400032 12.949 1.664E+02 1464200400033 12.991 9.229E+01 1464200400034 13.287 1.141E+02 1464200400035 13.572 1.138E+02 1464200400036 13.900 6.716E+01 1464200400037 14.176 7.223E+01 1464200400038 14.496 5.005E+01 1464200400039 14.797 3.289E+01 1464200400040 15.110 3.536E+01 1464200400041 15.389 1.375E+01 1464200400042 15.687 2.498E+01 1464200400043 15.989 1.866E+01 1464200400044 16.277 6.113E+00 1464200400045 16.586 1.599E+01 1464200400046 16.872 1.873E+01 1464200400047 17.185 4.171E+00 1464200400048 17.499 5.556E+00 1464200400049 17.791 1.800E+01 1464200400050 18.088 6.155E+00 1464200400051 18.994 2.918E+00 1464200400052 19.285 8.497E+00 1464200400053 ENDDATA 44 0 1464200400054 ENDSUBENT 53 0 1464200499999 ENDENTRY 4 0 1464299999999