ENTRY 21884 20211225 23062188400000001 SUBENT 21884001 20211225 23062188400100001 BIB 14 47 2188400100002 TITLE Search for Be-7 and Si-32 as products of ternary 2188400100003 fission of U-235 by thermal neutrons 2188400100004 AUTHOR (D.C.Aumann,H.Zeising) 2188400100005 REFERENCE (J,INC,16,171,1980) 2188400100006 INSTITUTE (2GERMUN) Institut fuer Radiochemie, Technische 2188400100007 Universitaet, Muenchen. 2188400100008 FACILITY (REAC,2GERMUN) The Munich Research Reactor. 2188400100009 INC-SOURCE (REAC) The samples were irradiated in the 2188400100010 graphite reflector of the reactor. 2188400100011 INC-SPECT The thermal neutron flux was 1.6E+13 neutrons/cm-sq*Se2188400100012 and 1.4E+13 neutrons/cm-sq*sec for the two samples, 2188400100013 respectively. 2188400100014 SAMPLE Two samples of about 555 Mg uranium enriched to about 2188400100015 90% U-235. Each sample consisted of 9 chips 2188400100016 of 55-65 Mg of uranium metal. Each chip was wrapped in2188400100017 aluminum foil (20 um thick). The chips were place in 2188400100018 larger aluminum cans, three by three, and three such 2188400100019 cans formed one sample. 2188400100020 METHOD (ACTIV) Irradiation time was about 30 days. 2188400100021 (CHSEP) Chemical separation 2188400100022 DETECTOR (GELI) A coaxial Ge(Li) detector with a 16.9% 2188400100023 photopeak efficiancy relative to a 3 inch * 3 inch 2188400100024 NaI(Tl) crystal and a resolution of 2.1 keV for the 2188400100025 1.33 MeV gamma-ray of Co-60 was used for detection of 2188400100026 the 478. keV gamma-ray of Be-7 and radiation from 2188400100027 Ba-140 used a monitor for the number of fissions. 2188400100028 The Be-samples were also counted in a calibrated 2188400100029 low-background gas flow window counter provided with 2188400100030 an anticoincidence guard counter to measure possible 2188400100031 beta activity of 1.6e+06 yr Be-10. the same beta- 2188400100032 counter was used to measure the beta activity of Si-322188400100033 and its daughter p-32 with half-life 14.28 d. 2188400100034 ANALYSIS The number of fissions in the irradiated U-235 sample 2188400100035 was determined from the amount of Ba-140 produced in 2188400100036 the sample. This number was determined to be 2188400100037 1.5e+19 and 0.9e+19 for the two samples, respectively 2188400100038 Since no or very small evidences for excistance 2188400100039 of activity were observed, only upper limits for 2188400100040 fission yields are given. 2188400100041 CORRECTION For 2188400100042 - detector efficiency 2188400100043 - chemical yield 2188400100044 - burn-up of produced fission products 2188400100045 ERR-ANALYS No details given. 2188400100046 HISTORY (19831219C) A.L. 2188400100047 (20211225A) SD:Updated to new date formats,lower case. 2188400100048 Corrections in all Subents. 2188400100049 ENDBIB 47 0 2188400100050 COMMON 1 3 2188400100051 EN-DUMMY 2188400100052 EV 2188400100053 2.5300E-02 2188400100054 ENDCOMMON 3 0 2188400100055 ENDSUBENT 54 0 2188400199999 SUBENT 21884002 20211225 23062188400200001 BIB 5 12 2188400200002 REACTION (92-U-235(N,F)ELEM/MASS,TER,FY,,MXW) 2188400200003 DECAY-DATA ((1.)4-BE-7,53.3D,DG,478.,0.1035) 2188400200004 ((2.)4-BE-10,1.6E+06YR,B-) 2188400200005 ((3.)14-SI-32,280.YR,B-) The daughter nucleus P-32 2188400200006 is also a beta- emitter. 2188400200007 From compiler: the currently known half-life is ~157 yr2188400200008 COMMENT The results show that ternary fission giving rise to 2188400200009 fragments of mass greater than that of the alpha 2188400200010 particle is extremely rare if it occurs at all. 2188400200011 STATUS (TABLE) Table 1 from Inorg.Nucl.Chem.Lett.,16(1980)171 2188400200012 HISTORY (20211225A) SD: SF5=CUM -> TER in REACTION code. 2188400200013 STATUS updated. COMMENT added. 2188400200014 ENDBIB 12 0 2188400200015 NOCOMMON 0 0 2188400200016 DATA 4 3 2188400200017 ELEMENT MASS DATA-MAX DECAY-FLAG 2188400200018 NO-DIM NO-DIM PC/FIS NO-DIM 2188400200019 4. 7. 2.00E-10 1. 2188400200020 4. 10. 3.00E-04 2. 2188400200021 14. 32. 1.20E-10 3. 2188400200022 ENDDATA 5 0 2188400200023 ENDSUBENT 22 0 2188400299999 ENDENTRY 2 0 2188499999999