ENTRY 10237 20190722 14541023700000001 SUBENT 10237001 20190722 14541023700100001 BIB 13 44 1023700100002 TITLE The ratio of the uranium-238 to uranium-235 fission 1023700100003 cross sections from 1 to 5 MeV 1023700100004 AUTHOR (J.W.Meadows) 1023700100005 INSTITUTE (1USAANL) 1023700100006 REFERENCE (J,NSE,49,310,1972) 1023700100007 (R,ANL-NDM-83,1983) Revised data in table 1023700100008 FACILITY (DYNAM,1USAANL) Argonne 8 MeV Tandem Dynamitron 1023700100009 INC-SOURCE (P-LI7) Targets produced by evaporation of Li on Ta 1023700100010 backing. 1023700100011 Target thicknesses about 200 keV above 2 MeV neutron 1023700100012 energy but thinner at lower energies. 1023700100013 SAMPLE Samples deposited on 0.25-mm thick polished stainless 1023700100014 steel or 0.13-mm thick Mo backings by electroplating 1023700100015 or by vacuum evaporation. 1023700100016 Below 2 MeV, deposit diameter 2.5 cm, approximate 1023700100017 thicknesses either 150 or 500 ug/cm2. 1023700100018 Above 3 MeV, deposit diameter 5 cm, thickness 1023700100019 approximately 500 ug/cm2. 1023700100020 DETECTOR (FISCH) Low-mass double ionization chamber using 1023700100021 methane as the counting gas. 1023700100022 Below 2 MeV, detector 5 cm from neutron source. 1023700100023 Above 3 MeV, detector 52 cm from neutron source. 1023700100024 METHOD (TOF) Time-of-flight used to reduce and measure 1023700100025 time-independent background. 1023700100026 Sample mass ratios for normalization measured by 1023700100027 comparing thermal thermal fission rate of 235U 1023700100028 samples and 238U samples containing 10% 235U. 1023700100029 Sample masses also measured by calorimetric analysis. 1023700100030 ANALYSIS 238U(n,f)/235U(n,f) shape ratio normalized to the 1023700100031 absolute ratio measured at 2.500, 2.890 and 3.256 MeV.1023700100032 CORRECTION Corrected for second 7Li(p,n) group, other uranium 1023700100033 isotopes, inelastic scattering in sample backings, 1023700100034 pulse-height extrapolation, and background. 1023700100035 Effects due to elastic scattering in sample supports, 1023700100036 sample geometry, and momentum effects were eliminated 1023700100037 by the normalization or by measurements in both 1023700100038 counter orientations. 1023700100039 STATUS (APRVD) J.W. Meadows, 1984/3/2. 1023700100040 HISTORY (19721030C) 1023700100041 (19750905A) BIB changes. 1023700100042 (19821015A) Converted to REACTION formalism 1023700100043 (19831230A) Revised as per ANL-NDM-83. 002-003 combined1023700100044 (20010309U) Updated to new date formats, lower case. 1023700100045 (20190722A) On. Major revision in 003. 1023700100046 ENDBIB 44 0 1023700100047 NOCOMMON 0 0 1023700100048 ENDSUBENT 47 0 1023700199999 NOSUBENT 10237002 19840306 14541023700200001 SUBENT 10237003 20190722 14541023700300001 BIB 6 22 1023700300002 REACTION 1((92-U-238(N,F),,SIG)/(92-U-235(N,F),,SIG)) 1023700300003 2(92-U-238(N,F),,SIG) 1023700300004 MONITOR 2(92-U-235(N,F),,SIG) 1023700300005 MONIT-REF 2(,,3,ENDF/B-V,,1978) 1023700300006 ERR-ANALYS1(ERR-T) Total error 1023700300007 - secondary source reactions (20% of correction) 1023700300008 - propagation from neutron energy error (~20% of the 1023700300009 energy resolution) 1023700300010 (ERR-1,,,F) Normalization of shape ratio: 1023700300011 - calorimetric analysis (0.50%) 1023700300012 - alpha counting excluding statistics (0.60%) 1023700300013 - thickness correction (0.18%) 1023700300014 - extrapolation (0.10%) 1023700300015 - dead time correction (0.25%) 1023700300016 - scattering correction (0.60%) 1023700300017 - statistical - alpha counting etc. (0.42%) 1023700300018 (ERR-2,,,U) Uncorrelated error, which principle due to 1023700300019 the counting statistics, but a part is based on the 1023700300020 consistency of repeated measurements. 1023700300021 STATUS (TABLE) Table XIII of ANL-NDM-83 1023700300022 HISTORY (20190722A) On. ERR-S -> ERR-2. ERR-1 added. 1023700300023 0.01776 -> 0.02776 at 1.146 MeV. 1023700300024 ENDBIB 22 0 1023700300025 COMMON 1 3 1023700300026 ERR-1 1023700300027 PER-CENT 1023700300028 1.12 1023700300029 ENDCOMMON 3 0 1023700300030 DATA 6 47 1023700300031 EN EN-RSL-FW DATA 1ERR-2 1ERR-T 1DATA 21023700300032 MEV MEV NO-DIM PER-CENT PER-CENT B 1023700300033 0.899 0.023 0.00997 3.72 3.86 0.01164 1023700300034 1.007 0.022 0.01267 2.34 3.54 0.01545 1023700300035 1.095 0.022 0.02187 3.10 3.66 0.02658 1023700300036 1.110 0.022 0.02132 1.91 2.70 0.02591 1023700300037 1.146 0.021 0.02776 3.25 3.64 0.03375 1023700300038 1.207 0.021 0.02912 1.91 3.21 0.03554 1023700300039 1.249 0.021 0.0336 1.56 4.02 0.0412 1023700300040 1.295 0.028 0.0511 1.53 6.55 0.0627 1023700300041 1.353 0.021 0.0829 2.55 5.25 0.1023 1023700300042 1.387 0.020 0.1173 2.04 4.63 0.1452 1023700300043 1.397 0.028 0.1323 1.11 5.97 0.1639 1023700300044 1.404 0.020 0.1528 1.24 4.32 0.1894 1023700300045 1.451 0.020 0.2041 1.70 5.02 0.2542 1023700300046 1.491 0.027 0.2717 1.16 2.97 0.3397 1023700300047 1.517 0.020 0.2721 1.04 1.82 0.3411 1023700300048 1.548 0.020 0.305 1.54 2.12 0.383 1023700300049 1.591 0.027 0.317 0.99 1.77 0.401 1023700300050 1.620 0.019 0.325 0.99 1.70 0.411 1023700300051 1.694 0.020 0.330 1.55 2.08 0.422 1023700300052 1.694 0.027 0.360 0.97 1.70 0.460 1023700300053 1.724 0.019 0.338 0.99 1.67 0.433 1023700300054 1.753 0.019 0.353 1.54 2.03 0.453 1023700300055 1.794 0.026 0.371 1.00 1.66 0.478 1023700300056 1.826 0.019 0.388 1.00 1.59 0.501 1023700300057 1.854 0.019 0.372 1.46 1.88 0.480 1023700300058 1.896 0.026 0.399 0.93 1.45 0.516 1023700300059 1.918 0.019 0.400 1.10 1.53 0.518 1023700300060 1.985 0.032 0.415 0.94 1.45 0.539 1023700300061 1.992 0.115 0.407 0.49 1.02 0.528 1023700300062 2.000 0.019 0.393 1.08 1.47 0.510 1023700300063 2.044 0.114 0.421 0.91 1.34 0.546 1023700300064 2.197 0.102 0.424 0.88 1.31 0.547 1023700300065 2.500 0.104 0.428 0.35 0.83 0.543 1023700300066 2.890 0.097 0.428 0.35 0.83 0.527 1023700300067 3.256 0.089 0.446 0.28 0.87 0.533 1023700300068 3.476 0.085 0.464 0.86 1.49 0.546 1023700300069 3.484 0.085 0.466 0.55 1.14 0.548 1023700300070 3.575 0.097 0.467 0.78 1.24 0.545 1023700300071 3.670 0.080 0.480 0.86 1.27 0.556 1023700300072 3.876 0.078 0.488 0.86 1.39 0.557 1023700300073 3.992 0.078 0.495 0.94 1.67 0.561 1023700300074 4.075 0.078 0.495 0.86 1.60 0.559 1023700300075 4.078 0.085 0.490 0.57 1.18 0.553 1023700300076 4.475 0.082 0.506 0.71 1.69 0.564 1023700300077 4.992 0.072 0.515 0.47 4.53 0.549 1023700300078 5.083 0.082 0.517 0.84 1.24 0.548 1023700300079 5.147 0.071 0.516 0.74 5.28 0.545 1023700300080 ENDDATA 49 0 1023700300081 ENDSUBENT 80 0 1023700399999 ENDENTRY 3 0 1023799999999