ENTRY 14733 20220118 14961473300000001 SUBENT 14733001 20220118 14961473300100001 BIB 9 17 1473300100002 TITLE The ratio of the fission cross sections of 49 and 25 1473300100003 for thermal neutrons and the ration [1+alpha(49)]/ 1473300100004 [1+alpha(25)] 1473300100005 AUTHOR (J.W.Dewire,R.R.Wilson,W.D.Woodward) 1473300100006 REFERENCE (R,LA-103,1944) 1473300100007 REL-REF (R,14734001,E.E.Anderson+,S,LA-91,1944) 239Pu 1473300100008 absorption cross section. 1473300100009 INSTITUTE (1USALAS) 1473300100010 FACILITY (CYCLO,1USALAS) 1473300100011 INC-SOURCE (D-BE) A thermalized neutron flux of about 2*10**5 1473300100012 neutrons/cm2/sec at the center of the 11'*7'*6'8" 1473300100013 graphite block at the cyclotron. 1473300100014 DETECTOR (IOCH) The comparison chamber consisted of two 1473300100015 parallel plate ionization chambers having a common 1473300100016 high voltage electrode, on which the samples were 1473300100017 placed. 1473300100018 HISTORY (20220118C) BP 1473300100019 ENDBIB 17 0 1473300100020 COMMON 1 3 1473300100021 EN-DUMMY 1473300100022 EV 1473300100023 0.0253 1473300100024 ENDCOMMON 3 0 1473300100025 ENDSUBENT 24 0 1473300199999 SUBENT 14733002 20220118 14961473300200001 BIB 5 14 1473300200002 REACTION ((94-PU-239(N,F),,SIG,,SPA)/(92-U-235(N,F),,SIG,,SPA)) 1473300200003 SAMPLE Six foils of 235U and four foils of 239Pu were used 1473300200004 in the experiment. All the foils were deposited on 1 1473300200005 or 2 mil Pt. All the weights are based on a half life 1473300200006 for 239Pu of 24,400 years. 1473300200007 ERR-ANALYS (DATA-ERR) In order to find any systematic errors in 1473300200008 counting, a 239Pu foil and a 235U foil were compared 1473300200009 under conditions obtained by separately interchanging 1473300200010 scalars, amplifiers, and foils, and by moving the 1473300200011 chamber within the block. No significant change in 1473300200012 the counting ratio were detected. No further details 1473300200013 on how the given uncertainty was determined. 1473300200014 DECAY-DATA (94-PU-239,24400.YR) 1473300200015 STATUS (TABLE) page 5. 1473300200016 ENDBIB 14 0 1473300200017 NOCOMMON 0 0 1473300200018 DATA 2 1 1473300200019 DATA DATA-ERR 1473300200020 NO-DIM NO-DIM 1473300200021 1.40 0.02 1473300200022 ENDDATA 3 0 1473300200023 ENDSUBENT 22 0 1473300299999 SUBENT 14733003 20220118 14961473300300001 BIB 4 10 1473300300002 REACTION (((94-PU-239(N,ABS),,SIG,,SPA)/ 1473300300003 (92-U-235(N,ABS),,SIG,,SPA))/ 1473300300004 ((94-PU-239(N,F),,SIG,,SPA)/(92-U-235(N,F),,SIG,,SPA)))1473300300005 ANALYSIS The following relation was used: [1+alpha(239Pu)]/ 1473300300006 [1+alpha(235U)] = ((sigma abs(239Pu)/sigma abs(235U))/ 1473300300007 (sigmaf(235U)/sigmaf(239Pu))). 1473300300008 ASSUMED (ASSUM1,94-PU-239(N,ABS),,SIG) 1473300300009 (ASSUM2,92-U-235(N,ABS),,SIG) 1473300300010 STATUS (DEP,14733002) 1473300300011 (TABLE) page 7. 1473300300012 ENDBIB 10 0 1473300300013 NOCOMMON 0 0 1473300300014 DATA 3 1 1473300300015 DATA ASSUM1 ASSUM2 1473300300016 NO-DIM B B 1473300300017 1.29 1056.0 640.0 1473300300018 ENDDATA 3 0 1473300300019 ENDSUBENT 18 0 1473300399999 ENDENTRY 3 0 1473399999999