ENTRY 41607 20181224 41814160700000001 SUBENT 41607001 20181224 41814160700100001 BIB 9 27 4160700100002 INSTITUTE (4RUSFEI) 4160700100003 REFERENCE (J,JET,10,290,1960) Engl.translation of: 4160700100004 (J,ZET,37,406,1959) 4160700100005 AUTHOR (B.D.Kuz'minov, L.S.Kutsarva, V.G.Nesterov, 4160700100006 L.I.Prokhorova, G.P.Smirenkin) 4160700100007 TITLE Some features of the spontaneous fission of U-238. 4160700100008 METHOD (COINC) Double coincidence. 4160700100009 Number of registered coincidences : ~2400 for U-238, 4160700100010 ~12000 for Pu-240. Three exp.runs. 4160700100011 DETECTOR (IOCH) Two multilayer ionization chambers to detect 4160700100012 spontaneous fission of U-238. Filled with Ar at 5 atm 4160700100013 pressure. 4160700100014 Identical chamber with Pu. Filled with 90%Ar + 10%CO(2)4160700100015 at 35 mm Hg pressure. 4160700100016 (BF3) The fis.chambers were surrounded by 24 4160700100017 proportional B-10F(3) counters in paraffin. 4160700100018 Efficiency of prompt fis.neutrons registration ~4.%. 4160700100019 Time resolution of electronic equipment ~6E-4 sec. 4160700100020 SAMPLE 12 g of uranium depleted of U-235 were deposited as 4160700100021 layers 2 mg/cm2 thick on both sides of Al foils. 4160700100022 2.5 mg mass, Pu-240 - 92%, Pu-238 - 8.%. 4160700100023 On platinum foil. 4160700100024 CORRECTION - Random coincidences for Pu-240 - < 0.2%, 4160700100025 for U-238 - ~0.01%, were not taken into account. 4160700100026 - for nonuniform efficiency along the neutron detector.4160700100027 HISTORY (20150702C) M.M. 4160700100028 (20181224U) Subent 002 was corrected 4160700100029 ENDBIB 27 0 4160700100030 NOCOMMON 0 0 4160700100031 ENDSUBENT 30 0 4160700199999 SUBENT 41607002 20181224 41814160700200001 BIB 9 18 4160700200002 REACTION 1(92-U-238(0,F),PR,NU) 4160700200003 2((92-U-238(0,F),PR,NU)/(94-PU-240(0,F),PR,NU)) 4160700200004 MONITOR 1(94-PU-240(0,F),PR,NU) 4160700200005 MONIT-REF 1(,R.B.Leachman,C,58GENEVA,15,229,1958) Report No.2467 4160700200006 DECAY-DATA (92-U-238,6.5E+15HR) 4160700200007 U-238 spontaneous fission HL was measured to be 4160700200008 (6.5+-0.3)*10**15 years. 4160700200009 REL-REF (A,,K.W.Geiger+,J,CJP,32,498,1954) 4160700200010 Agree with value 2.26+-0.16 of K.W.Geiger+. 4160700200011 (D,,D.J.Littler,J,PPS/A,65,203,1952) 4160700200012 Smaller then value 2.4+-0.2 of D.J.Littler . 4160700200013 ADD-RES Q (number of neutrons emitted in unit time by a gram 4160700200014 of uranium) was measured in three ways to be 4160700200015 64.5+-2 n/(g*hr). 4160700200016 Decay constant was defined to be 31.0+-1.5 fis/(g*hr). 4160700200017 ERR-ANALYS (DATA-ERR) Errors are not specified. 4160700200018 STATUS (TABLE) Text, p. 291 of J.Exp.Theor.Physics,10,290,19604160700200019 HISTORY (20181224U) MONIT-REF, REL-REF were corrected 4160700200020 ENDBIB 18 0 4160700200021 COMMON 1 3 4160700200022 ERR-HL 4160700200023 YR 4160700200024 0.3E+15 4160700200025 ENDCOMMON 3 0 4160700200026 DATA 6 1 4160700200027 DATA 1DATA-ERR 1MONIT 1MONIT-ERR 1DATA 2DATA-ERR 24160700200028 PRT/FIS PRT/FIS PRT/FIS PRT/FIS NO-DIM NO-DIM 4160700200029 0.92 0.03 2.26 0.05 2.1 0.1 4160700200030 ENDDATA 3 0 4160700200031 ENDSUBENT 30 0 4160700299999 ENDENTRY 2 0 4160799999999