ENTRY 32553 20010417 00003255300000001 SUBENT 32553001 20010417 00003255300100001 BIB 13 60 3255300100002 INSTITUTE (3CPRAEP) 3255300100003 REFERENCE (J,HFH,20,(3),129,199808) in Chinese. 3255300100004 AUTHOR (ZHANG SHENGDONG,GUO JINGRU,CUI ANZHI,LI DAMING, 3255300100005 ZHANG SHULAN,SUN HONGQING,YANG YI,LI HUI) 3255300100006 TITLE Measurement of fission yield of Cs-135 from thermal 3255300100007 neutron induced fission of U-235 by neutron activation 3255300100008 analysis 3255300100009 FACILITY (REAC) Heavy-water reactor 3255300100010 INC-SOURCE Thermal neutrons from heavy-water reflecting layer 3255300100011 channel. The epithermal parameter was 0.02980 and the 3255300100012 error was 0.00103. The neutron flux density was 3255300100013 3.99e+13cm2s. 3255300100014 METHOD (RCHEM,ACTIV) Fission products were separated from the 3255300100015 U-235 irradiation samples by radiochemical separation 3255300100016 method and weighted for determination of the chemical 3255300100017 recovery factor. 3255300100018 DETECTOR (HPGE) A 143cm3 high-purity germanium detector with 3255300100019 resolution (FWHM) 1.78keV at 1332keV gamma ray of 3255300100020 Co-60 was used for gamma measurement. 3255300100021 By energy-efficiency curve, the efficiency of Cs-136 3255300100022 Cs-137 and Au-198 were as follows: 3255300100023 Nucleus Gamma-energy(kev) Purity(%) Efficiency(%)3255300100024 Cs-137 661.6 85.1 1.27 3255300100025 Au-198 441.8 94.7 1.71 3255300100026 Cs-136 818.5 100.0 1.08 3255300100027 340.6 44.5 1.84 3255300100028 1048.1 80.5 0.91 3255300100029 The geometrical efficiency of recoil-catch was 3255300100030 approximate 40% for Cs-137 and Cs-135. 3255300100031 MONITOR (79-AU-197(N,G)79-AU-198,,SIG) 3255300100032 (92-U-235(N,F)55-CS-137,IND,FY,,FIS) 3255300100033 SAMPLE Aluminium is used underlaying of uranium. Uranium were 3255300100034 269mm2 in active area (18.5mm in diameter)and 100ug 3255300100035 in weight. The irradiation time was 66.0 hours. 3255300100036 The aluminium catcher was 50mg/cm2 in mass thickness 3255300100037 and 27.0mm in diameter, a aluminium circle was settled 3255300100038 on its surface and covered with two aluminium foils 3255300100039 on the circle. 3255300100040 ERR-ANALYS 1. The error from monitor were as follows: 3255300100041 - 1.7% neutron flux density 3255300100042 - 0.3% counting statistics 3255300100043 - 0.2% Au-197 standard solution sampling 3255300100044 - 0.8% other error of Au-197 targets were 3255300100045 irradiated in the same time 3255300100046 - 1.0% efficiency for Au-198 3255300100047 - 0.5% density of Au-197 solution 3255300100048 - 0.3% activation cross section for Au-197 3255300100049 2. Activity of Cs-136 in Al catcher 3255300100050 - 0.8% counting statistics 3255300100051 - 1.0% detector efficiency 3255300100052 - 1.7% neutron flux density 3255300100053 - 5.7% activation cross section 3255300100054 Total error was 6.1%. 3255300100055 3. Activity of Cs-137 in Al catcher 3255300100056 - 0.1% counting statistics 3255300100057 - 1.0% detector efficiency 3255300100058 Total error was 1.1%. 3255300100059 STATUS Data taken from part 3.5 in the paper of chinese J,HFH,3255300100060 20,(3),129,199808. 3255300100061 HISTORY (20010417C) by Chen Guochang 3255300100062 ENDBIB 60 0 3255300100063 NOCOMMON 0 0 3255300100064 ENDSUBENT 63 0 3255300199999 SUBENT 32553002 20010417 00003255300200001 BIB 1 1 3255300200002 REACTION (92-U-235(N,F)55-CS-135,CUM,FY,,MXW) 3255300200003 ENDBIB 1 0 3255300200004 COMMON 1 3 3255300200005 EN-DUMMY 3255300200006 EV 3255300200007 0.0253 3255300200008 ENDCOMMON 3 0 3255300200009 DATA 2 1 3255300200010 DATA ERR-T 3255300200011 PC/FIS PC/FIS 3255300200012 6.34 0.46 3255300200013 ENDDATA 3 0 3255300200014 ENDSUBENT 13 0 3255300299999 ENDENTRY 2 0 3255399999999