ENTRY 12399 20220822 15001239900000001 SUBENT 12399001 20220822 15001239900100001 BIB 12 48 1239900100002 INSTITUTE (1USAANL) 1239900100003 REFERENCE (J,JNE,21,157,1967) 1239900100004 AUTHOR (J.W.Meadows,J.F.Whalen) 1239900100005 TITLE Energy dependence of Nu bar (p) for neutron-induced 1239900100006 fission of U235 below 1.0 MeV. 1239900100007 FACILITY (VDG,1USAANL) 1239900100008 INC-SOURCE (P-LI7) The thickness of the lithium targets was 1239900100009 adjusted so that the energy loss of a proton passing 1239900100010 through them corresponded to a neutron energy spread 1239900100011 of 0.04-0.06 MeV except at the two points near 0.04 MeV1239900100012 SAMPLE The fissionable material was spread uniformly over the 1239900100013 plates that used as a fission chamber.The 235U detector1239900100014 contained 187 mg of uranium enriched to 96%; while the 1239900100015 252Cf detector contained enough californium to give 1239900100016 approx. 600 fissions per minute. 1239900100017 METHOD Two fission detectors, one containing 235U and the 1239900100018 other 252Cf, were surrounded by the neutron detector. 1239900100019 Neutrons entered through the tapered collimator. A 1239900100020 fission pulse started a time analyser which recorded 1239900100021 the neutron time distribution in 1024 channels for 1239900100022 1200 mu-sec after the fission. Two time distributions 1239900100023 were recorded, one for fission pulses originating in 1239900100024 the 235U detector and one for those originating in the 1239900100025 252Cf detector (see REL-REF). 1239900100026 REL-REF (M,,J.F.Whalen+,J,RSI,35,682,1964) 1239900100027 DETECTOR (BF3) The neutron detector consisted of twenty-four 1239900100028 BF3 counters arranged in two concentric rings of twelve1239900100029 each and embedded in a paraffin cylinder 46 cm long and1239900100030 51 cm in diameter. A tube, 8-6 cm in diameter, passing 1239900100031 through the centre cylinder contained the fission 1239900100032 detectors. All surfaces of the paraffin cylinder were 1239900100033 covered with 0.5 mm cadmium sheet. The measured 1239900100034 efficiency of this detector for 252Cf neutrons was 1239900100035 9.42+-0.07% occupying a region 4 cm long. 1239900100036 (FISCH) The fission detectors were multiple plate ion 1239900100037 chambers, each having ten plates and occupying a region1239900100038 4 cm long. The two chambers were separated by a plate 1239900100039 thick enough to prevent the passage of fission 1239900100040 fragments. 1239900100041 STATUS (TABLE) Table 2 of J.Nucl.Energy 21(1967)157 1239900100042 HISTORY (19760804T) Translated from SCISRS 1239900100043 (19800507U) Converted to reaction formalism 1239900100044 (19841018A) Data heading corrected. 1239900100045 (20070426A) DR Subentry 4 added. 1239900100046 (20110806A) SD: BIB updated. Data units in Subent 002 1239900100047 changed. Fields in NODATA of Sub.003 corrected1239900100048 (20220630A) OS. MONITOR moved from sub.1 to sub.2, 1239900100049 STATUS updated, errors updated in sub.2 1239900100050 ENDBIB 48 0 1239900100051 NOCOMMON 0 0 1239900100052 ENDSUBENT 51 0 1239900199999 SUBENT 12399002 20220822 15001239900200001 BIB 6 9 1239900200002 REACTION (92-U-235(N,F),PR,NU) 1239900200003 MONITOR (98-CF-252(0,F),,NU) 1239900200004 MONIT-REF (21252001,D.S.Mather+,J,PR,133,B1403,1964) 1239900200005 ERR-ANALYS (ERR-1) Relative error 1239900200006 (ERR-T) Total error 1239900200007 STATUS (DEP,12399004) U235/Cf252 ratios 1239900200008 HISTORY (20110806A) SD: Data units changed: NO-DIM to PRT/FIS. 1239900200009 (20220630A) Monitor moved from sub.1, ERR-1 added, 1239900200010 STATUS added 1239900200011 ENDBIB 9 0 1239900200012 COMMON 2 3 1239900200013 MONIT MONIT-ERR 1239900200014 NO-DIM NO-DIM 1239900200015 3.782 0.02 1239900200016 ENDCOMMON 3 0 1239900200017 DATA 5 16 1239900200018 EN EN-RSL DATA ERR-1 ERR-T 1239900200019 MEV MEV PRT/FIS PRT/FIS PRT/FIS 1239900200020 0.039 0.05 2.422 0.017 0.023 1239900200021 0.046 0.05 2.423 0.016 0.027 1239900200022 0.15 0.032 2.462 0.018 0.024 1239900200023 0.225 0.03 2.48 0.018 0.024 1239900200024 0.265 0.028 2.47 0.022 0.027 1239900200025 0.298 0.027 2.472 0.022 0.027 1239900200026 0.325 0.027 2.514 0.018 0.024 1239900200027 0.358 0.025 2.436 0.018 0.024 1239900200028 0.375 0.025 2.477 0.022 0.027 1239900200029 0.405 0.025 2.468 0.022 0.027 1239900200030 0.425 0.025 2.534 0.017 0.023 1239900200031 0.476 0.024 2.512 0.019 0.024 1239900200032 0.548 0.021 2.489 0.017 0.023 1239900200033 0.675 0.018 2.514 0.017 0.023 1239900200034 0.785 0.021 2.527 0.014 0.021 1239900200035 1. 0.02 2.561 0.016 0.023 1239900200036 ENDDATA 18 0 1239900200037 ENDSUBENT 36 0 1239900299999 SUBENT 12399003 20110806 13741239900300001 BIB 3 3 1239900300002 REACTION (92-U-235(N,F),PR,NU) 1239900300003 STATUS (SPSDD,12399002) 1239900300004 HISTORY (19800507A) Data superseded 1239900300005 ENDBIB 3 0 1239900300006 NOCOMMON 0 0 1239900300007 NODATA 0 0 1239900300008 ENDSUBENT 7 0 1239900399999 SUBENT 12399004 20070426 13441239900400001 BIB 1 1 1239900400002 REACTION ((92-U-235(N,F),PR,NU)/(98-CF-252(0,F),PR,NU)) 1239900400003 ENDBIB 1 0 1239900400004 NOCOMMON 0 0 1239900400005 DATA 3 16 1239900400006 EN EN-RSL DATA 1239900400007 MEV MEV NO-DIM 1239900400008 0.039 0.050 0.6403 1239900400009 0.046 0.050 0.6404 1239900400010 0.150 0.032 0.6509 1239900400011 0.225 0.030 0.6557 1239900400012 0.265 0.028 0.6531 1239900400013 0.298 0.027 0.6537 1239900400014 0.325 0.027 0.6646 1239900400015 0.358 0.025 0.6440 1239900400016 0.375 0.025 0.6549 1239900400017 0.405 0.025 0.6526 1239900400018 0.425 0.025 0.6700 1239900400019 0.476 0.024 0.6643 1239900400020 0.548 0.021 0.6582 1239900400021 0.675 0.018 0.6646 1239900400022 0.785 0.021 0.6682 1239900400023 1.000 0.020 0.6771 1239900400024 ENDDATA 18 0 1239900400025 ENDSUBENT 24 0 1239900499999 ENDENTRY 4 0 1239999999999