ENTRY 33002 20110817 31523300200000001 SUBENT 33002001 20110817 31523300200100001 BIB 14 76 3300200100002 TITLE Mass distribution in the thermal neutron induced 3300200100003 fission of 229-Th 3300200100004 AUTHOR (R.J.Singh, S.S.Rattan, A.V.R.Reddy, 3300200100005 C.R.Venkatasubramani, A.Ramaswami, 3300200100006 Satya Prakash, M.V.Ramaniah) 3300200100007 Old name = S.S.Rattan, New name = Sarbjit Singh 3300200100008 INSTITUTE (3INDTRM) 3300200100009 REFERENCE (J,RCA,31,69,1982) 3300200100010 FACILITY (REAC,3INDTRM) Cirus reactor 3300200100011 INC-SPECT Thermal neutron flux of ~5.0E12 n/sec/cm**2 3300200100012 SAMPLE Targets of 229Th and 235U were prepared on platinum 3300200100013 backing by electro deposition using isopropyl alcohol 3300200100014 METHOD (REC) The fission fragments were collected by the 3300200100015 thin target-recoil-catcher technique. 3300200100016 (RCHEM) Low yield products were measured by 3300200100017 radiochemical separation followed by beta/gamma ray 3300200100018 counting 3300200100019 (GSPEC) High yield fission products were measured by 3300200100020 gamma ray spectrometry. 3300200100021 (EXTB) Thermal neutron from CIRUS reactor were used. 3300200100022 (RELFY) The fission product yields were measured 3300200100023 relative to the thermal neutron induced fission of 3300200100024 235U. 3300200100025 DETECTOR (GELI) For high yield products. 3300200100026 (PROPC) End window gas flow proportional counter, for 3300200100027 low yield products. 3300200100028 MONITOR 235U targets (0.1 ug) were irradiated together with 3300200100029 the 229Th targets (30 ug). 3300200100030 Activities of the 235U fission products were measured 3300200100031 in the same way as those of 229Th. 3300200100032 The 235U fission product mass chain yields were taken 3300200100033 from the compilation of Meek and Rider. 3300200100034 The 91Sr yield is used as monitor for yield of any 3300200100035 other fission products of 229Th. 3300200100036 ANALYSIS (DECAY) The decay of each product was followed for 3300200100037 suitable length of time to determine the activity at 3300200100038 the end of irradiation 3300200100039 Assuming that charge distribution pattern is similar 3300200100040 in 229Th and 235U fission, the chain yields of 235U 3300200100041 were used to calculate the respective chain yields 3300200100042 in 229Th. 3300200100043 91Sr was taken as an internal standard for both 229Th 3300200100044 and 235U fission, so as to eliminate any error due 3300200100045 to change in flux from one irradiation to another. 3300200100046 The final mass yield values were obtained by 3300200100047 normalising the area under the mass distribution 3300200100048 curve to 200%. 3300200100049 CORRECTION Chemical yield corrections were incorporated wherever 3300200100050 chemistry was carried out. 3300200100051 The decay for a suitable number of gamma rays of 3300200100052 the nuclides were followed for suitable length of 3300200100053 time to determine the activity at the end of 3300200100054 irradiation. 3300200100055 The correction for the decay during the irradiation 3300200100056 were getting cancelled as the samples were irradiated 3300200100057 simultaneously both for 229Th and 235U. 3300200100058 The errors due detector efficiency, self absorption 3300200100059 and scattering were getting cancelled as the samples 3300200100060 were counted in similar geometry. 3300200100061 It was assumed that the genetic relations are same 3300200100062 both in case of 229Th and 235U fission products and 3300200100063 under the conditions of the experiment. 3300200100064 The correction due to fast fission of 229Th and 235U 3300200100065 were negligible. 3300200100066 No corrections were applied for neutron capture. 3300200100067 STATUS (TABLE) Table 1 of Radiochim.Acta 31(1982)69 3300200100068 HISTORY (20060906C) Data was initially compiled to EXFOR by 3300200100069 Paresh Prajapati of M.S.University of Baroda and 3300200100070 S.V.Suryanarayana, H.Naik and S.Ganesan of Bhabha 3300200100071 Atomic Research Centre, Mumbai, India. 3300200100072 (20080328A) The data entries were recompiled, checked 33300200100073 and corrected by Sarbjit Singh (Author) of Bhabha 3300200100074 Atomic Research Centre, Mumbai, India. 3300200100075 (20080826A) SD,On. Energy changed from EN on EN-DUMMY 3300200100076 in Subent 002 added SPA in reaction code 3300200100077 (20110818A) On. ANALYSIS, METHOD modified. 3300200100078 ENDBIB 76 0 3300200100079 NOCOMMON 0 0 3300200100080 ENDSUBENT 79 0 3300200199999 SUBENT 33002002 20110817 31523300200200001 BIB 4 6 3300200200002 REACTION (90-TH-229(N,F)MASS,CHN,FY,,SPA) 3300200200003 DECAY-DATA Taken from chart of nuclides prepared by 3300200200004 W.Seelmann-Eggebert et al., Institute for Radiochemie,3300200200005 KFK,1974 3300200200006 ERR-ANALYS (ERR-S) Statistical, given as 1 standard deviation 3300200200007 HISTORY (20110817A) On. RESULT deleted 3300200200008 ENDBIB 6 0 3300200200009 COMMON 1 3 3300200200010 EN-DUMMY 3300200200011 EV 3300200200012 0.0253 3300200200013 ENDCOMMON 3 0 3300200200014 DATA 3 28 3300200200015 MASS DATA ERR-S 3300200200016 NO-DIM PC/FIS PC/FIS 3300200200017 77. 0.0091 0.0010 3300200200018 83. 4.51 0.05 3300200200019 85. 9.83 1.47 3300200200020 88. 9.23 0.60 3300200200021 89. 8.6 2.1 3300200200022 91. 7.11 0.15 3300200200023 92. 6.53 0.27 3300200200024 97. 0.86 0.05 3300200200025 99. 0.33 0.06 3300200200026 111. 0.030 0.008 3300200200027 112. 0.033 0.012 3300200200028 113. 0.036 0.008 3300200200029 115. 0.022 0.004 3300200200030 121. 0.012 0.002 3300200200031 125. 0.033 0.010 3300200200032 126. 0.055 0.011 3300200200033 127. 0.050 0.010 3300200200034 131. 0.576 0.015 3300200200035 132. 1.29 0.12 3300200200036 133. 2.91 0.10 3300200200037 134. 5.96 0.42 3300200200038 135. 6.50 0.59 3300200200039 138. 8.63 0.50 3300200200040 139. 8.79 0.60 3300200200041 140. 9.22 1.31 3300200200042 142. 7.48 0.40 3300200200043 143. 7.55 0.10 3300200200044 147. 2.56 0.13 3300200200045 ENDDATA 30 0 3300200200046 ENDSUBENT 45 0 3300200299999 ENDENTRY 2 0 3300299999999