ENTRY 14495 20180312 14391449500000001 SUBENT 14495001 20180312 14391449500100001 BIB 9 21 1449500100002 TITLE Search for Radiochemical Evidence for Ternary Fission 1449500100003 of 235U by Thermal Neutrons 1449500100004 AUTHOR (R.W.Stoenner,M.Hillman) 1449500100005 REFERENCE (J,PR,142,716,1966) 1449500100006 #doi:10.1103/PhysRev.142.716 1449500100007 REL-REF (D,,M.L.Muga,J,PRL,11,129,1963) 1449500100008 INSTITUTE (1USABNL) 1449500100009 FACILITY (REAC,1USABNL) Brookhaven Graphite Research Reactor. 1449500100010 INC-SPECT Reactor spectrum. 1449500100011 ANALYSIS All of the fission yields must, however, be expressed 1449500100012 as upper limits for the following reasons: (a) no 1449500100013 firm evidence for 42Ar or for 56 Co was found; the 1449500100014 method of analyses used merely assumed that some was 1449500100015 present, and (b) 37Ar, 39Ar, and 41Ar could have been 1449500100016 formed by reactions of neutrons with trace impurities 1449500100017 in the sample, such as (n,gamma) reactions with argon, 1449500100018 (n,p) reactions with potassium, and (n,alpha) 1449500100019 reactions with calcium. A reasonable upper limit to 1449500100020 assign each yield is the sum of the calculated yield 1449500100021 and its standard deviation. 1449500100022 HISTORY (20180312C) BP 1449500100023 ENDBIB 21 0 1449500100024 COMMON 1 3 1449500100025 EN-DUMMY 1449500100026 EV 1449500100027 0.0253 1449500100028 ENDCOMMON 3 0 1449500100029 ENDSUBENT 28 0 1449500199999 SUBENT 14495002 20180312 14391449500200001 BIB 7 17 1449500200002 REACTION (92-U-235(N,F)18-AR-37,(CUM),FY,,SPA) 1449500200003 DETECTOR (PROPC) 1449500200004 SAMPLE The irradiated uranium sample, a part of a reactor 1449500200005 fuel plate containing approximately 2.5 mg of 235U 1449500200006 and 125 mg of aluminum. 1449500200007 METHOD (CHSEP,RELFY) The sample was irradiated for 3.85 yr. 1449500200008 The sample was dissolved in the presence of measured 1449500200009 amounts of argon, krypton, and xenon carriers with 6N 1449500200010 hydrochloric acid containing a trace of platinic 1449500200011 chloride as a catalyst. The recovery of each rare gas 1449500200012 was measured; chemical yields were always more than 1449500200013 95%. The difference of activities of the argon 1449500200014 counted through a thin window (39Ar) and internally in 1449500200015 a gas counter was taken as the 37Ar activity. 1449500200016 MONITOR (92-U-235(N,F)36-KR-85,CUM,FY,,SPA) 1449500200017 MONIT-REF ((MONIT)13215001,S.Katcoff+,J,JIN,27,1447,1965) 1449500200018 STATUS (TABLE) Table II, page 718. 1449500200019 ENDBIB 17 0 1449500200020 COMMON 1 3 1449500200021 MONIT 1449500200022 PC/FIS 1449500200023 0.273 1449500200024 ENDCOMMON 3 0 1449500200025 DATA 1 1 1449500200026 DATA-MAX 1449500200027 PC/FIS 1449500200028 1.0E-7 1449500200029 ENDDATA 3 0 1449500200030 ENDSUBENT 29 0 1449500299999 SUBENT 14495003 20180312 14391449500300001 BIB 7 18 1449500300002 REACTION (92-U-235(N,F)18-AR-39,(CUM),FY,,SPA) 1449500300003 DETECTOR (PROPC) 1449500300004 SAMPLE The irradiated uranium sample, a part of a reactor 1449500300005 fuel plate containing approximately 2.5 mg of 235U 1449500300006 and 125 mg of aluminum. 1449500300007 METHOD (CHSEP,RELFY) The sample was irradiated for 3.85 yr. 1449500300008 The sample was dissolved in the presence of measured 1449500300009 amounts of argon, krypton, and xenon carriers with 6N 1449500300010 hydrochloric acid containing a trace of platinic 1449500300011 chloride as a catalyst. The recovery of each rare gas 1449500300012 was measured; chemical yields were always more than 1449500300013 95%. The 39Ar disintegration rate was measured by 1449500300014 transferring the argon sample from the 42Ar 1449500300015 determination to the envelope surrounding a thin-wall 1449500300016 counter. 1449500300017 MONITOR (92-U-235(N,F)36-KR-85,CUM,FY,,SPA) 1449500300018 MONIT-REF ((MONIT)13215001,S.Katcoff+,J,JIN,27,1447,1965) 1449500300019 STATUS (TABLE) Table II, page 718. 1449500300020 ENDBIB 18 0 1449500300021 COMMON 1 3 1449500300022 MONIT 1449500300023 PC/FIS 1449500300024 0.273 1449500300025 ENDCOMMON 3 0 1449500300026 DATA 1 1 1449500300027 DATA-MAX 1449500300028 PC/FIS 1449500300029 4.0E-7 1449500300030 ENDDATA 3 0 1449500300031 ENDSUBENT 30 0 1449500399999 SUBENT 14495004 20180312 14391449500400001 BIB 7 16 1449500400002 REACTION (92-U-235(N,F)18-AR-41,(CUM),FY,,SPA) 1449500400003 DETECTOR (PROPC) 1449500400004 SAMPLE The irradiated uranium sample, a part of a reactor 1449500400005 fuel plate containing approximately 2.5 mg of 235U 1449500400006 and 125 mg of aluminum. 1449500400007 METHOD (CHSEP,RELFY) The sample was irradiated for 2.0 h. 1449500400008 The sample was dissolved in the presence of measured 1449500400009 amounts of argon, krypton, and xenon carriers with 6N 1449500400010 hydrochloric acid containing a trace of platinic 1449500400011 chloride as a catalyst. The recovery of each rare gas 1449500400012 was measured; chemical yields were always more than 1449500400013 95%. Counting of 41Ar was begun about three 1449500400014 half-lives after the end of irradiation. 1449500400015 MONITOR (92-U-235(N,F)36-KR-85,CUM,FY,,SPA) 1449500400016 MONIT-REF ((MONIT)13215001,S.Katcoff+,J,JIN,27,1447,1965) 1449500400017 STATUS (TABLE) Table II, page 718. 1449500400018 ENDBIB 16 0 1449500400019 COMMON 1 3 1449500400020 MONIT 1449500400021 PC/FIS 1449500400022 0.273 1449500400023 ENDCOMMON 3 0 1449500400024 DATA 1 1 1449500400025 DATA-MAX 1449500400026 PC/FIS 1449500400027 3.0E-9 1449500400028 ENDDATA 3 0 1449500400029 ENDSUBENT 28 0 1449500499999 SUBENT 14495005 20180312 14391449500500001 BIB 7 28 1449500500002 REACTION (92-U-235(N,F)18-AR-42,(CUM),FY,,SPA) 1449500500003 DETECTOR (GEMUC) A low-level G.M. gas counter (30 mm x4 mm, 1449500500004 background 0.026+-0.002 counts/min) was filled with the1449500500005 argon. 1449500500006 SAMPLE The irradiated uranium sample, a part of a reactor 1449500500007 fuel plate containing approximately 2.5 mg of 235U 1449500500008 and 125 mg of aluminum. 1449500500009 METHOD (CHSEP,RELFY) The sample was irradiated for 3.85 yr. 1449500500010 The sample was dissolved in the presence of measured 1449500500011 amounts of argon, krypton, and xenon carriers with 6N 1449500500012 hydrochloric acid containing a trace of platinic 1449500500013 chloride as a catalyst. The recovery of each rare gas 1449500500014 was measured; chemical yields were always more than 1449500500015 95%. 42K was allowed to grow in, the argon was removed,1449500500016 and then the 42K was counted. No evidence for 42K 1449500500017 activity was observed. An upper limit for 42K 1449500500018 activity was determined by two methods: 1449500500019 (1) the difference between a long count of the sample 1449500500020 and of the background was taken as the number of 1449500500021 atoms of 42K at the beginning of the count, and 1449500500022 (2) a least-squares decay-curve analysis was 1449500500023 performed assuming the presence of 42K and background. 1449500500024 The fission yields obtained from the two methods are 1449500500025 (1.1+-1.7)x10**-11% and (0.6+-0.8)x10**-11%, 1449500500026 respectively. 1449500500027 MONITOR (92-U-235(N,F)36-KR-85,CUM,FY,,SPA) 1449500500028 MONIT-REF ((MONIT)13215001,S.Katcoff+,J,JIN,27,1447,1965) 1449500500029 STATUS (TABLE) Table II, page 718. 1449500500030 ENDBIB 28 0 1449500500031 COMMON 1 3 1449500500032 MONIT 1449500500033 PC/FIS 1449500500034 0.273 1449500500035 ENDCOMMON 3 0 1449500500036 DATA 1 1 1449500500037 DATA-MAX 1449500500038 PC/FIS 1449500500039 3.0E-11 1449500500040 ENDDATA 3 0 1449500500041 ENDSUBENT 40 0 1449500599999 SUBENT 14495006 20180312 14391449500600001 BIB 5 10 1449500600002 REACTION (92-U-235(N,F)27-CO-56,(CUM),FY,,SPA) 1449500600003 SAMPLE A sample of 12 mg of 235U as uranyl sulfate wrapped 1449500600004 in sufficient aluminum to stop all fission recoil. 1449500600005 DETECTOR (NAICR) 76 mm x 76 mm NaI(Tl) detector. 1449500600006 METHOD (CHSEP,FPGAM) The sample was irradiated for 19.9 1449500600007 days. Gamma spectra were measured with a NaI(Tl) 1449500600008 detector. After subtraction of a standard 60Co 1449500600009 background gamma spectrum from the gamma spectrum of 1449500600010 the sample, no firm evidence was found for 56Co. 1449500600011 STATUS (TABLE) Table II, page 718. 1449500600012 ENDBIB 10 0 1449500600013 NOCOMMON 0 0 1449500600014 DATA 1 1 1449500600015 DATA-MAX 1449500600016 PC/FIS 1449500600017 8.0E-8 1449500600018 ENDDATA 3 0 1449500600019 ENDSUBENT 18 0 1449500699999 ENDENTRY 6 0 1449599999999