ENTRY L0059 19970129 0000L005900000001 SUBENT L0059001 19970129 0000L005900100001 BIB 13 71 L005900100002 INSTITUTE (1USAUI ) L005900100003 REFERENCE (T,YOUNG,72) L005900100004 AUTHOR (L.M.YOUNG) L005900100005 TITLE Photoneutron cross-sections and spectra from L005900100006 monoenergetic photons on yttrium, praseodymium, L005900100007 lead, and bismuth in the giant-resonance. L005900100008 FACILITY (BETAT,1USAUI ) 22 MeV Betatron. L005900100009 INC-SOURCE (QMPH,TAGD) Gamma-ray energy known to within 3-4%. L005900100010 Monochromatic gamma rays were tagged by momentum L005900100011 analyzing the post Bremsstrahlung electron associated L005900100012 with the gamma ray. L005900100013 DETECTOR (SCIN) LIQUID SCINTILLATOR DETECTOR. L005900100014 METHOD (TOF,PSD) The energy of neutrons was obtained by L005900100015 measuring the neutrons time-of-flight. L005900100016 Pulse shape discrimination was used to differentiate L005900100017 between events caused by gamma rays and by neutrons L005900100018 in the liquid scintillator. L005900100019 ANALYSIS Photoneutron cross sections were calculated from the L005900100020 experimental neutron energy spectra. L005900100021 The neutron spectra can be represented by: L005900100022 Number-N(E(n)) = B(T(n)) + L005900100023 function(dsigma(T(n),E(gamma))/D(T(n)*D(omega), L005900100024 where B(T(n)) = number of accidental events for T(n) L005900100025 T(n) = time of flight of neutrons of energy E(n)L005900100026 The data were analysed by parameterizing the backgroundL005900100027 and the differential cross section in equation L005900100028 mentioned above. L005900100029 The background was parameterized as a constant, while L005900100030 the differential cross section was parameterized usingL005900100031 the method of Kuchnir, see Phys.Rev.,161,1236 (1967). L005900100032 CORRECTION Two corrections were made to the total cross sections L005900100033 to compensate for neutron scattering: L005900100034 1) Corrected for neutron scattering by the collimator L005900100035 leading to counts in the detector, using a Monte L005900100036 Carlo technique to find an ideal line shape of the L005900100037 time-of-flight spectrum from monoenergetic isotropic L005900100038 neutron source at the center of the target. L005900100039 2) Corrected for neutron scattering in the target. L005900100040 This changed the initial isotropic neutron L005900100041 distribution to an anisotropic distribution favoring L005900100042 normal emission to the front face of the target. L005900100043 The corrections for neutron scattering in the targets L005900100044 of Y, Pr, Pb, and Bi were 17, 20, 14, and 29%, L005900100045 respectively. L005900100046 ERR-ANALYS (DATA-ERR2) Systematic errors due to uncertainties in L005900100047 gamma ray intensity, neutron detector efficiency, and L005900100048 the monte carlo calculations are estimated to be of L005900100049 the order of 10%. L005900100050 COMMENT All photoneutron cross sections measured can be L005900100051 described very well with a Lorenzian line shape; in L005900100052 some cases there is a small intermediate structure L005900100053 modifying the otherwise smooth cross sections and L005900100054 making them somewhat 'bumpy'. L005900100055 Measurements in all four elements show evidence for L005900100056 intermediate structure. In some cases, the structure L005900100057 is quite well defined. On the other hand, there is L005900100058 definitely no large scale intermediate structure L005900100059 similar to that was reported previously for cross L005900100060 sections which were derived by unfolding the yield L005900100061 curves obtained from electron Bremsstrahlung gamma L005900100062 rays with small increments in the end-point energy. L005900100063 The integrated cross section of the giant resonance forL005900100064 nuclei studied, in units of the classical dipole sum, L005900100065 increases linearly with A. This value is unity for A L005900100066 near 140 and about 1.25 for A near 200. The accuracy L005900100067 of this dependence on A and the absolute values, L005900100068 depends on the corrections for neutron scattering in L005900100069 the target, the efficiency of the neutron detector, L005900100070 and the photon flux. L005900100071 HISTORY (891201C) L005900100072 (950407A) BIB Updated L005900100073 ENDBIB 71 0 L005900100074 COMMON 1 3 L005900100075 DATA-ERR2 L005900100076 PER-CENT L005900100077 10. L005900100078 ENDCOMMON 3 0 L005900100079 ENDSUBENT 78 0 L005900199999 SUBENT L0059002 19970129 0000L005900200001 BIB 4 7 L005900200002 REACTION (39-Y-89(G,N)39-Y-88,,SIG) L005900200003 SAMPLE Target consisted of 1797 grams of natural metallic L005900200004 praseodymium covered with a thin layer of epoxy. L005900200005 ERR-ANALYS (DATA-ERR1) Statistical uncertainties only, derived L005900200006 from the calculation of the cross sections and includeL005900200007 the errors in the parameters used in this calculation L005900200008 STATUS Converted from Berman compilation. L005900200009 ENDBIB 7 0 L005900200010 NOCOMMON 0 0 L005900200011 DATA 3 47 L005900200012 EN DATA DATA-ERR1 L005900200013 MEV MB MB L005900200014 13.426 28.56 3.77 L005900200015 13.538 23.40 3.26 L005900200016 13.638 32.62 3.65 L005900200017 13.769 42.90 3.11 L005900200018 13.896 47.18 3.67 L005900200019 14.038 56.20 3.71 L005900200020 14.188 59.61 3.63 L005900200021 14.341 58.88 3.67 L005900200022 14.498 62.64 4.17 L005900200023 14.517 64.60 4.87 L005900200024 14.597 81.60 5.16 L005900200025 14.611 91.84 4.73 L005900200026 14.682 82.74 5.00 L005900200027 14.752 78.83 4.27 L005900200028 14.798 85.37 4.83 L005900200029 14.856 89.88 4.87 L005900200030 14.858 93.78 2.98 L005900200031 14.915 100.97 5.23 L005900200032 14.960 86.90 4.54 L005900200033 15.072 100.94 4.27 L005900200034 15.082 95.28 4.56 L005900200035 15.171 105.48 5.20 L005900200036 15.207 107.67 4.31 L005900200037 15.292 115.92 5.50 L005900200038 15.356 118.66 4.66 L005900200039 15.416 132.98 5.78 L005900200040 15.507 118.95 4.60 L005900200041 15.539 145.91 7.03 L005900200042 15.634 161.65 6.64 L005900200043 15.748 162.02 6.84 L005900200044 15.838 158.43 5.00 L005900200045 15.992 167.40 5.16 L005900200046 16.136 170.58 5.93 L005900200047 16.269 167.02 5.83 L005900200048 16.376 204.81 8.00 L005900200049 16.391 208.75 6.30 L005900200050 16.497 180.76 7.65 L005900200051 16.644 208.89 8.04 L005900200052 16.780 193.94 7.71 L005900200053 16.939 203.76 7.63 L005900200054 17.118 211.31 7.73 L005900200055 17.288 199.00 7.65 L005900200056 17.464 181.37 7.48 L005900200057 17.634 175.25 7.80 L005900200058 17.806 167.64 8.46 L005900200059 17.938 139.86 8.21 L005900200060 18.092 143.77 7.82 L005900200061 ENDDATA 49 0 L005900200062 ENDSUBENT 61 0 L005900299999 SUBENT L0059003 19970129 0000L005900300001 BIB 5 10 L005900300002 REACTION ((59-PR-141(G,N)59-PR-140,,SIG)+ L005900300003 (59-PR-141(G,N+P)58-CE-139,,SIG)) L005900300004 Threshold of the reaction (gamma,n+p) is 14.4 MeV. L005900300005 SAMPLE Target consisted of 1797 grams of natural metallic L005900300006 praseodymium covered with a thin layer of epoxy. L005900300007 ERR-ANALYS (DATA-ERR1) Statistical uncertainties only, derived L005900300008 from the calculation of the cross sections and includeL005900300009 the errors in the parameters used in this calculation L005900300010 HISTORY (950407A) REACTION corrected. L005900300011 STATUS Converted from Berman compilation. L005900300012 ENDBIB 10 0 L005900300013 NOCOMMON 0 0 L005900300014 DATA 3 59 L005900300015 EN DATA DATA-ERR1 L005900300016 MEV MB MB L005900300017 10.993 35.38 2.92 L005900300018 11.078 37.45 3.05 L005900300019 11.158 38.66 3.69 L005900300020 11.260 41.02 3.53 L005900300021 11.388 41.03 3.33 L005900300022 11.504 41.65 3.38 L005900300023 11.621 51.56 3.81 L005900300024 11.735 51.64 3.63 L005900300025 11.873 50.37 3.94 L005900300026 11.978 63.30 4.07 L005900300027 12.070 45.65 3.51 L005900300028 12.176 70.07 3.10 L005900300029 12.257 76.37 4.27 L005900300030 12.346 89.43 3.66 L005900300031 12.464 94.48 3.58 L005900300032 12.588 97.32 3.71 L005900300033 12.719 112.71 3.89 L005900300034 12.859 94.17 3.71 L005900300035 12.996 126.80 4.40 L005900300036 13.110 133.62 4.15 L005900300037 13.238 155.78 5.12 L005900300038 13.367 161.81 5.30 L005900300039 13.451 163.55 3.71 L005900300040 13.464 173.17 5.09 L005900300041 13.549 185.59 5.17 L005900300042 13.640 202.89 5.43 L005900300043 13.800 208.87 5.45 L005900300044 13.910 223.84 5.17 L005900300045 14.051 242.15 5.45 L005900300046 14.187 259.20 5.30 L005900300047 14.343 274.79 5.99 L005900300048 14.504 299.93 6.35 L005900300049 14.608 289.06 6.73 L005900300050 14.749 303.17 6.81 L005900300051 14.843 312.34 7.83 L005900300052 14.861 295.94 5.40 L005900300053 14.970 285.81 8.88 L005900300054 15.070 321.26 9.21 L005900300055 15.207 332.04 8.73 L005900300056 15.358 351.68 8.85 L005900300057 15.500 310.15 8.62 L005900300058 15.656 277.64 8.39 L005900300059 15.845 319.85 9.14 L005900300060 15.997 291.60 9.19 L005900300061 16.134 299.32 10.70 L005900300062 16.257 267.05 10.16 L005900300063 16.370 292.50 9.75 L005900300064 16.397 254.45 7.93 L005900300065 16.505 249.46 9.19 L005900300066 16.644 265.11 9.67 L005900300067 16.785 226.27 9.01 L005900300068 16.953 240.89 9.29 L005900300069 17.123 206.74 9.01 L005900300070 17.285 184.15 8.21 L005900300071 17.471 184.73 8.27 L005900300072 17.640 151.04 8.50 L005900300073 17.804 182.78 9.26 L005900300074 17.951 144.97 9.37 L005900300075 18.093 153.39 9.34 L005900300076 ENDDATA 61 0 L005900300077 ENDSUBENT 76 0 L005900399999 SUBENT L0059004 19970129 0000L005900400001 BIB 4 7 L005900400002 REACTION (82-PB-208(G,N)82-PB-207,,SIG) L005900400003 SAMPLE Target consisted of 2325 grams of radiolead with L005900400004 isotope composition of 72.6% Pb208 and 25.6% Pb206. L005900400005 ERR-ANALYS (DATA-ERR1) Statistical uncertainties only, derived L005900400006 from the calculation of the cross sections and includeL005900400007 the errors in the parameters used in this calculation L005900400008 STATUS Converted from Berman compilation. L005900400009 ENDBIB 7 0 L005900400010 NOCOMMON 0 0 L005900400011 DATA 3 58 L005900400012 EN DATA DATA-ERR1 L005900400013 MEV MB MB L005900400014 8.955 33.87 6.19 L005900400015 9.013 36.16 6.65 L005900400016 9.095 55.03 6.81 L005900400017 9.180 50.92 6.19 L005900400018 9.287 56.74 6.19 L005900400019 9.395 71.14 7.62 L005900400020 9.485 69.75 7.88 L005900400021 9.600 48.81 7.52 L005900400022 9.704 90.79 8.49 L005900400023 9.800 67.96 9.52 L005900400024 9.875 74.65 10.79 L005900400025 9.929 91.63 8.55 L005900400026 9.950 118.79 11.05 L005900400027 10.005 133.41 9.52 L005900400028 10.090 107.00 9.42 L005900400029 10.188 73.88 8.65 L005900400030 10.297 100.42 9.62 L005900400031 10.419 116.67 8.39 L005900400032 10.526 169.86 10.85 L005900400033 10.629 122.06 9.31 L005900400034 10.735 154.68 11.56 L005900400035 10.844 192.78 12.94 L005900400036 10.934 112.85 12.54 L005900400037 11.019 176.94 14.02 L005900400038 11.230 303.07 8.19 L005900400039 11.305 320.35 7.78 L005900400040 11.401 274.14 7.42 L005900400041 11.510 273.05 6.55 L005900400042 11.626 300.04 6.96 L005900400043 11.749 290.05 6.70 L005900400044 11.872 327.12 8.29 L005900400045 11.993 346.28 7.73 L005900400046 12.113 354.14 8.95 L005900400047 12.152 410.62 11.41 L005900400048 12.245 432.91 11.62 L005900400049 12.251 410.91 14.17 L005900400050 12.338 440.11 11.46 L005900400051 12.460 456.72 11.72 L005900400052 12.580 491.03 12.07 L005900400053 12.717 498.27 11.36 L005900400054 12.863 548.54 12.02 L005900400055 12.993 600.19 12.43 L005900400056 13.120 627.70 13.66 L005900400057 13.231 639.29 14.43 L005900400058 13.340 651.96 14.53 L005900400059 13.444 609.74 12.95 L005900400060 13.453 625.24 11.16 L005900400061 13.539 620.88 12.54 L005900400062 13.645 703.49 13.51 L005900400063 13.766 630.00 13.10 L005900400064 13.913 633.91 13.35 L005900400065 14.043 619.98 12.23 L005900400066 14.193 592.07 10.95 L005900400067 14.340 580.33 12.64 L005900400068 14.489 561.27 12.02 L005900400069 14.609 501.34 13.41 L005900400070 14.745 503.11 13.66 L005900400071 14.852 469.99 12.69 L005900400072 ENDDATA 60 0 L005900400073 ENDSUBENT 72 0 L005900499999 SUBENT L0059005 19970129 0000L005900500001 BIB 4 9 L005900500002 REACTION ((83-BI-209(G,N)83-BI-208,,SIG)+ L005900500003 (83-BI-209(G,N+P)82-PB-207,,SIG)) L005900500004 Threshold of the reaction (gamma,n+p) is about 11.2 MeVL005900500005 SAMPLE Target consisted of 3821 grams of natural metallic L005900500006 bismuth. L005900500007 ERR-ANALYS (DATA-ERR1) Statistical uncertainties only, derived L005900500008 from the calculation of the cross sections and includ L005900500009 the errors in the parameters used in this calculation L005900500010 STATUS Converted from Berman compilation. L005900500011 ENDBIB 9 0 L005900500012 NOCOMMON 0 0 L005900500013 DATA 3 46 L005900500014 EN DATA DATA-ERR1 L005900500015 MEV MB MB L005900500016 10.011 100.47 6.71 L005900500017 10.096 117.28 6.14 L005900500018 10.197 122.10 6.40 L005900500019 10.307 111.35 6.45 L005900500020 10.404 114.74 6.50 L005900500021 10.538 121.34 6.40 L005900500022 10.636 146.28 7.22 L005900500023 10.734 134.98 8.96 L005900500024 10.832 157.41 9.53 L005900500025 10.934 166.43 9.68 L005900500026 11.011 192.83 11.93 L005900500027 11.070 191.01 11.98 L005900500028 11.171 258.61 12.75 L005900500029 11.260 270.60 11.37 L005900500030 11.385 307.36 11.83 L005900500031 11.494 294.82 11.94 L005900500032 11.627 283.81 11.83 L005900500033 11.757 362.82 13.78 L005900500034 11.867 322.42 13.47 L005900500035 11.985 330.71 15.88 L005900500036 12.071 388.03 16.49 L005900500037 12.153 387.38 11.68 L005900500038 12.176 400.37 16.08 L005900500039 12.243 441.16 16.13 L005900500040 12.339 460.93 15.57 L005900500041 12.446 487.97 14.70 L005900500042 12.584 520.79 15.41 L005900500043 12.726 556.27 15.31 L005900500044 12.844 495.53 15.06 L005900500045 12.985 626.00 16.65 L005900500046 13.115 658.82 17.77 L005900500047 13.228 638.95 19.36 L005900500048 13.336 653.09 18.90 L005900500049 13.407 629.91 9.89 L005900500050 13.452 605.93 19.93 L005900500051 13.511 631.15 8.70 L005900500052 13.637 624.28 9.88 L005900500053 13.742 634.17 8.45 L005900500054 13.887 640.92 9.32 L005900500055 14.030 618.38 8.76 L005900500056 14.176 590.46 8.45 L005900500057 14.325 575.95 8.24 L005900500058 14.480 522.78 8.71 L005900500059 14.598 495.75 9.47 L005900500060 14.736 489.49 9.53 L005900500061 14.844 448.22 9.47 L005900500062 ENDDATA 48 0 L005900500063 ENDSUBENT 62 0 L005900599999 SUBENT L0059006 19970129 0000L005900600001 BIB 2 5 L005900600002 REACTION ((83-BI-209(G,N)83-BI-208,,INT)+ L005900600003 (83-BI-209(G,N+P)82-PB-207,,INT)) L005900600004 Integral of the Lorenzian curve. L005900600005 Threshold of the reaction (gamma,n+p) is ABOUT 11.2 ME L005900600006 STATUS (DEP,L0059005) L005900600007 ENDBIB 5 0 L005900600008 NOCOMMON 0 0 L005900600009 DATA 3 1 L005900600010 EN-MIN EN-MAX DATA L005900600011 MEV MEV MB*MEV L005900600012 7.5 15. 3820. L005900600013 ENDDATA 3 0 L005900600014 ENDSUBENT 13 0 L005900699999 SUBENT L0059007 19970129 0000L005900700001 BIB 2 3 L005900700002 REACTION (82-PB-208(G,N)82-PB-207,,INT) L005900700003 Integral of the Lorenzian curve. L005900700004 STATUS (DEP,L0059004) L005900700005 ENDBIB 3 0 L005900700006 NOCOMMON 0 0 L005900700007 DATA 3 1 L005900700008 EN-MIN EN-MAX DATA L005900700009 MEV MEV MB*MEV L005900700010 7.4 15. 3840. L005900700011 ENDDATA 3 0 L005900700012 ENDSUBENT 11 0 L005900799999 SUBENT L0059008 19970129 0000L005900800001 BIB 3 6 L005900800002 REACTION ((59-PR-141(G,N)59-PR-140,,INT)+ L005900800003 (59-PR-141(G,N+P)58-CE-139,,INT)) L005900800004 Threshold of the reaction (gamma,n+p) is 14.4 MeV. L005900800005 Integral of the Lorenzian curve. L005900800006 STATUS (DEP,L0059003) L005900800007 HISTORY (950407A) REACTION corrected. L005900800008 ENDBIB 6 0 L005900800009 NOCOMMON 0 0 L005900800010 DATA 3 1 L005900800011 EN-MIN EN-MAX DATA L005900800012 MEV MEV MB*MEV L005900800013 9.4 18. 2080. L005900800014 ENDDATA 3 0 L005900800015 ENDSUBENT 14 0 L005900899999 SUBENT L0059009 19970129 0000L005900900001 BIB 2 3 L005900900002 REACTION (39-Y-89(G,N)39-Y-88,,INT) L005900900003 Integral of the Lorenzian curve. L005900900004 STATUS (DEP,L0059002) L005900900005 ENDBIB 3 0 L005900900006 NOCOMMON 0 0 L005900900007 DATA 3 1 L005900900008 EN-MIN EN-MAX DATA L005900900009 MEV MEV MB*MEV L005900900010 11.5 18. 1157. L005900900011 ENDDATA 3 0 L005900900012 ENDSUBENT 11 0 L005900999999 ENDENTRY 9 0 L005999999999