ENTRY 22176 19910523 00002217600000001 SUBENT 22176001 19910523 00002217600100001 BIB 17 63 2217600100002 REFERENCE (J,RCA,50,1,90) 2217600100003 TITLE -ISOMERIC YIELD RATIOS OF 134-I AND 136-I AND 2217600100004 INDEPENDENT FRACTIONAL YIELDS OF SOME HALOGEN ISOTOPES2217600100005 IN THE FISSION OF 232-TH WITH REACTOR NEUTRONS. 2217600100006 AUTHOR (R.HENTZSCHEL,H.O.DENSCHLAG) 2217600100007 INSTITUTE (2GERMNZ) 2217600100008 FACILITY (REAC,2GERMNZ) THE FAST PNEUMATIC TUBE FACILITY OF THE 2217600100009 MAINZ TRIGA REACTOR. 2217600100010 INC-SOURCE (REAC ) THE IRRADIATION POSITION IN THE REACTOR WAS 2217600100011 WRAPPED IN A CD SHEET TO REDUCE GAMMA DOSE FROM 2217600100012 232-TH(N,G) AND WAS CHARACTERISED BY AN INTEGRATED 2217600100013 FAST, EPI-CADMIUM NEUTRON FLUX OF THE ORDER OF 2217600100014 1.5E+12 NEUTRONS/CM2 (100 MILLI-SEC NEUTRON PULSE). 2217600100015 INC-SPECT .FAST REACTOR EPI-CADMIUM SPECTRUM WITH AN ESTIMATED 2217600100016 MEAN EFFECTIVE NEUTRON ENERGY FOR 232-TH(N,F) OF 3 MEV2217600100017 SAMPLE .POLYSTYRENE CAPSULES FILLED WITH A SOLUTION OF 0.5 G 2217600100018 232-TH AS NITRATE IN 1.5 ML OF 2 M HNO3, CONTAINING 2217600100019 0.1 ML OF SATURATED SOLUTION OF NA2SO3, PLUS SUITABLE 2217600100020 ADDED AMOUNTS OF IODINE CARRIER AND HOLD-BACK CARRIERS2217600100021 TE(6+), SN(2+) AND SB(3+). IRRADIATION TIMES WERE 2217600100022 100 MILLI-SEC. 2217600100023 METHOD (CHSEP) FAST AUTOMATED RADIOCHEMICAL SEPARATION USING 2217600100024 PNEUMATIC TRANSPORT AND COMPUTER CONTROL. THE I AND BR2217600100025 WERE COLLECTED ON A PREFORMED AGCL FILTER LAYER BY 2217600100026 ION EXCHANGE WITH A CHEMICAL YIELD OF ABOUT 90 %. 2217600100027 (RELFY) THE HIGH SPIN ISOTOPES OF 134-,136-I USED AS 2217600100028 INTERNAL STANDARDS TO MONITOR FISSION EVENTS AND 2217600100029 CHEMICAL YIELD SINCE THEY HAVE NO BETA PRECURSORS. 2217600100030 THE COMPLEX DECAY CURVE OF THE 1313 KEV GAMMA FROM 2217600100031 136H-I AND 136L-I WAS RESOLVED MATHEMATICALLY IN EACH 2217600100032 EXPERIMENT. 2217600100033 ANALYSIS (DECAY) GROWTH AND DECAY CURVES AS A FUNCTION OF 2217600100034 WAITING TIME BETWEEN END OF IRRADIATION AND CHEMICAL 2217600100035 SEPARATION WERE ANALYSED TO EVALUATE THE FRACTIONAL 2217600100036 INDEPENDENT YIELDS. 2217600100037 DETECTOR (HPGE ) FIXED GEOMETRY COUNTING WITH AN EFFICIENCY 2217600100038 CALIBRATED 155 CM3 HPGE DETECTOR, RESOLUTION 1.9 KEV 2217600100039 AT 1333 KEV. INITIAL HIGH DEAD-TIMES CONTINUOUSLY 2217600100040 CORRECTED USING A LOSS-FREE COUNTING MODULE. 2217600100041 PART-DET (DG ) 2217600100042 DECAY-DATA (53-I-134-M,3.8MIN,DG,271.9,.790) 2217600100043 (53-I-134-G,52.8MIN,DG,847.0,.954) 2217600100044 (53-I-135,6.61HR,DG,1260.4,.286) 2217600100045 (53-I-136-M,45.SEC,DG,381.4,.998) 2217600100046 DG,1313.0,1.0) 2217600100047 (53-I-136-G,84.SEC,DG,1313.0,1.0) 2217600100048 (36-KR-85-M,4.48HR,DG,151.2,.750) 2217600100049 (35-BR-86,54.SEC,DG,1564.9,.644) 2217600100050 CORRECTION .THE LOW COUNTING RATE OF 134-I NECESSITATED A 2217600100051 DETECTION EFFICIENCY AS HIGH AS POSSIBLE (SAMPLE - 2217600100052 DETECTOR DISTANCE = 1 CM), CONSEQUENTLY A CORRECTION 2217600100053 FOR GEOMETRICAL SUMMING LOSSES WAS NECESSARY (UP TO 2217600100054 30%). 2217600100055 .CORRECTION MADE FOR SMALL 134-TE CONTAMINATION. 2217600100056 .CORRECTION FOR SUPERPOSITION OF SOME GAMMAS 2217600100057 .136-I YIELD CORRECTED BY 1 % FOR FRACTIONAL 2217600100058 INDEPENDENT YIELD OF 136-XE. 2217600100059 ERR-ANALYS (DATA-ERR) INCLUDES ERRORS OF THE PEAK-AREA STATISTICS,2217600100060 DETECTION EFFICIENCY, GAMMA ABUNDANCES, LEAST SQUARE 2217600100061 ANALYSIS FITTING. 2217600100062 STATUS .DATA TAKEN FROM MAIN REF. 2217600100063 HISTORY (910516C) S.W. 2217600100064 (910523E) 2217600100065 ENDBIB 63 0 2217600100066 COMMON 1 3 2217600100067 EN-MEAN 2217600100068 MEV 2217600100069 3.0000E+00 2217600100070 ENDCOMMON 3 0 2217600100071 ENDSUBENT 70 0 2217600199999 SUBENT 22176002 19910523 00002217600200001 BIB 3 8 2217600200002 REACTION 1(90-TH-232(N,F)53-I-134-M/T,IND,FY/RAT,,SPA) 2217600200003 2(90-TH-232(N,F)53-I-136-M/T,IND,FY/RAT,,SPA) 2217600200004 YIELD RATIOS OF HIGH SPIN TO (HIGH + LOW) SPIN STATES:2217600200005 53-I-134-H SPIN = -8, 53-I-134-L SPIN = +4 2217600200006 53-I-136-H SPIN = -6, 53-I-136-L SPIN = -2 2217600200007 STATUS .DATA TAKEN FROM MAIN REF. 2217600200008 HISTORY (910516C) S.W. 2217600200009 (910523E) 2217600200010 ENDBIB 8 0 2217600200011 NOCOMMON 0 0 2217600200012 DATA 4 1 2217600200013 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 2217600200014 NO-DIM NO-DIM NO-DIM NO-DIM 2217600200015 0.47 0.05 0.71 0.05 2217600200016 ENDDATA 3 0 2217600200017 ENDSUBENT 16 0 2217600299999 SUBENT 22176003 19910523 00002217600300001 BIB 3 9 2217600300002 REACTION ((90-TH-232(N,F)ELEM/MASS,IND,FY,,SPA)/ 2217600300003 (90-TH-232(N,F)53-I-136,CUM,FY,,SPA)) 2217600300004 THE INDEPENDENT YIELDS ARE QUOTED AS A FRACTION OF THE2217600300005 TOTAL 136-I (HIGH + LOW SPIN) YIELD MEASURED AFTER THE2217600300006 DECAY OF 136-TE AND EXTRAPOLATED BACK TO ZERO DELAY 2217600300007 TIME AFTER IRRADIATION. 2217600300008 STATUS .DATA TAKEN FROM MAIN REF. 2217600300009 HISTORY (910516C) S.W. 2217600300010 (910523E) 2217600300011 ENDBIB 9 0 2217600300012 NOCOMMON 0 0 2217600300013 DATA 4 5 2217600300014 ELEMENT MASS DATA DATA-ERR 2217600300015 NO-DIM NO-DIM NO-DIM NO-DIM 2217600300016 35. 85. 0.047 0.005 2217600300017 35. 86. 0.184 0.04 2217600300018 53. 134. 0.016 0.004 2217600300019 53. 135. 0.162 0.03 2217600300020 53. 136. 0.334 0.06 2217600300021 ENDDATA 7 0 2217600300022 ENDSUBENT 21 0 2217600399999 ENDENTRY 3 0 2217699999999