ENTRY 10296 20011227 00001029600000001 SUBENT 10296001 20011227 00001029600100001 BIB 14 36 1029600100002 INSTITUTE (1USAANL) 1029600100003 REFERENCE (C,70ANL,,281,1970) 1029600100004 AUTHOR (W.P.Poenitz) 1029600100005 TITLE Measurements of the 235U fission cross section at 552 1029600100006 and 644 keV 1029600100007 FACILITY (VDG) 3-MeV Van de Graaff. 1029600100008 INC-SOURCE 51V(p,n)51Cr reaction. Target was positioned in the 1029600100009 center of a spherical ionization chamber. 1029600100010 SAMPLE Uranium layer, 99.8% 235U and 120 micro-g/cm2 thick, 1029600100011 deposited on the inner sphere of ionization chamber 1029600100012 using molecular plating. 1029600100013 MONITOR 51Cr activity associated with neutrons from 51V(p,n) 1029600100014 source reaction used to determine absolute neutron 1029600100015 flux. 1029600100016 DETECTOR (FISCH) Fission events were measured by a spherical 1029600100017 ionization chamber surrounding the source. 0.025 cm. 1029600100018 thick silver spheres had a diameter of 3 inches 1029600100019 (inner sphere) 5 inches (outer sphere). 1029600100020 Alpha activity was counted in the ionization chamber. 1029600100021 After the end of the run, gamma activity of the target1029600100022 was measured with a calibrated Na(Tl) detector. 1029600100023 PART-DET (A) 1029600100024 CORRECTION A total coorection of 3.6% applied for effects of: 1029600100025 . total absorption of fission fragments, 1029600100026 . backscattering of neutrons from outer sphere, 1029600100027 . increase of the flight path in 235U for neutrons 1029600100028 scattered in the inner sphere, 1029600100029 . inelastic scattering of neutrons in target and 1029600100030 counter, 1029600100031 . backscattering of neutrons from the construction 1029600100032 materials, 1029600100033 ERR-ANALYS (DATA-ERR) Total error, statistical plus systematic. 1029600100034 STATUS (APRVD) Approved by author 1029600100035 HISTORY (19730115C) 1029600100036 (19830117A) Converted to REACTION formalism 1029600100037 (20011227A) Updated to new date formats, lower case. 1029600100038 ENDBIB 36 0 1029600100039 NOCOMMON 0 0 1029600100040 ENDSUBENT 39 0 1029600199999 SUBENT 10296002 20011227 00001029600200001 BIB 1 1 1029600200002 REACTION (92-U-235(N,F),,SIG) 1029600200003 ENDBIB 1 0 1029600200004 NOCOMMON 0 0 1029600200005 DATA 3 2 1029600200006 EN DATA DATA-ERR 1029600200007 KEV B B 1029600200008 552. 1.085 0.043 1029600200009 644. 1.066 0.042 1029600200010 ENDDATA 4 0 1029600200011 ENDSUBENT 10 0 1029600299999 ENDENTRY 2 0 1029699999999