ENTRY 21615 20121109 22342161500000001 SUBENT 21615001 20121109 22342161500100001 BIB 12 43 2161500100002 INSTITUTE (2JPNWDA) Waseda university, Tokyo, Japan. 2161500100003 REFERENCE (J,NIM,154,335,1978) 2161500100004 AUTHOR (M.Kase,J.Kikuchi,T.Doke) 2161500100005 TITLE Half-life of U-238 spontaneous fission and its 2161500100006 fragment kinetic energies 2161500100007 FACILITY .No facility used. 2161500100008 SAMPLE .Natural uranium oxide (mainly U3O8) fixed on the 2161500100009 cathode surface of the ionization chamber, 458 mg 2161500100010 in weight and 0.108 mg/cm2 in thickness. 2161500100011 METHOD (PSD) Pulse-shaping circuit of a semi-Gaussian 2161500100012 type used with the ionization chamber. 2161500100013 DETECTOR (IOCH) A cylindrical gridded ionization chamber, 2161500100014 with an area of 5000 cm2. 2161500100015 ANALYSIS .The energy calibration was performed by using the 2161500100016 following relation, 2161500100017 E=AX+B 2161500100018 where E is the kinetic energy of a fission fragment, 2161500100019 X is the pulse height and A and B are constants. 2161500100020 .The following assumptions were made, 2161500100021 the constant A is not dependent on the mass and 2161500100022 equal to a constant for alpha particles, 2161500100023 the mass distribution of U-238 spontaneous fission 2161500100024 is equal to that of U-235 thermal neutron induced 2161500100025 fission. 2161500100026 STATUS (TABLE) .Data taken from Nucl.Instr.&Meth.154,335,1978 2161500100027 CORRECTION .For- 2161500100028 - contribution from U-235 fission induced by cosmic- 2161500100029 ray produced thermal neutrons (negligibly small), 2161500100030 - pile-up pulses from alpha-particles, which 2161500100031 above 25 MeV becomes negligibly small. 2161500100032 - Electronic noise pulses from the external 2161500100033 disturbances (no correction necessary), 2161500100034 - effects of the self-absorption and cylindrical 2161500100035 geometry of the cathode. 2161500100036 HISTORY (19800804C) CN. 2161500100037 (19800808E) 2161500100038 (19840106U) A.P.T. Japan code changed to JPN 2161500100039 (19840106E) 2161500100040 (20121109A) SD: Updated to new date formats,lower case.2161500100041 Corrected according last EXFOR rules and Dict. 2161500100042 INC-SOURCE deleted, relevant only to MONITOR reaction 2161500100043 (Subent 2). REACTION code in Subent 2 corrected. 2161500100044 Subent 2 split in two. Other minor corrections. 2161500100045 ENDBIB 43 0 2161500100046 NOCOMMON 0 0 2161500100047 ENDSUBENT 46 0 2161500199999 SUBENT 21615002 20121109 22342161500200001 BIB 4 18 2161500200002 REACTION 1(92-U-238(0,F),,AKE,HF) 2161500200003 2(92-U-238(0,F),,AKE,LF) 2161500200004 Average kinetic energy of fission fragments. 2161500200005 MONITOR 1(92-U-235(N,F),SEC,AKE,HF,MXW) 2161500200006 2(92-U-235(N,F),SEC,AKE,LF,MXW) Average values of post 2161500200007 neutron-emission energies for fragments from U-235 2161500200008 thermal-neutron-induced fission. 2161500200009 The kinetic energy spectrum of 235U thermalneutron- 2161500200010 induced fission was measured, in order to check the 2161500200011 saturation characteristics of pulse height and to 2161500200012 calibrate the energies of fragments from 2161500200013 238U spontaneous fission. 2161500200014 (AM-BE) An Am-Be neutron source, thermalized by a 2161500200015 paraffin wall of 30 cm thickness, used for satura- 2161500200016 tion characteristics and energy calibration. 2161500200017 MONIT-REF (,F.Shiraishi+,J,NIM,107,493,1973) 2161500200018 HISTORY (20121109A) SD: REACTION code split in two codes. 2161500200019 data of FF moved to Subent 3. 2161500200020 ENDBIB 18 0 2161500200021 COMMON 1 3 2161500200022 EN-NRM 2161500200023 EV 2161500200024 2.5300E-02 2161500200025 ENDCOMMON 3 0 2161500200026 DATA 6 1 2161500200027 DATA 1DATA-ERR 1MONIT 1DATA 2DATA-ERR 2MONIT 22161500200028 MEV MEV MEV MEV MEV MEV 2161500200029 6.7000E+01 1.2000E+00 6.6780E+01 9.7600E+01 7.0000E-01 9.9740E+012161500200030 ENDDATA 3 0 2161500200031 ENDSUBENT 30 0 2161500299999 SUBENT 21615003 20121109 22342161500300001 BIB 3 4 2161500300002 REACTION (92-U-238(0,F),SEC,AKE,LF+HF) 2161500300003 Average kinetic energy of fission fragments. 2161500300004 STATUS (DEP,21615002) Sum of LF+HF 2161500300005 HISTORY (20121109C) SD. 2161500300006 ENDBIB 4 0 2161500300007 NOCOMMON 0 0 2161500300008 DATA 2 1 2161500300009 DATA DATA-ERR 2161500300010 MEV MEV 2161500300011 1.6460E+02 1.9000E+00 2161500300012 ENDDATA 3 0 2161500300013 ENDSUBENT 12 0 2161500399999 ENDENTRY 3 0 2161599999999