ENTRY 20438 19840118 00002043800000001 SUBENT 20438001 19840118 00002043800100001 BIB 12 38 2043800100002 INSTITUTE (2SWTWUR) 2043800100003 REFERENCE (J,JIN,32,3441,7011) 2043800100004 (P,EANDC(OR)-93,7006) PROGRESS REPORT, FINAL VALUE. 2043800100005 (P,EANDC(OR)-75,27,68) PRELIMINARY RESULT. 2043800100006 AUTHOR (H.R.VON GUNTEN, K.F.FLYNN, A.SCHMID) 2043800100007 TITLE -THE THERMAL-NEUTRON FISSION CROSS-SECTION OF TH-227.- 2043800100008 INC-SOURCE (REAC ) E.I.R. SWIMMING-POOL REACTOR SAPHIR. 2043800100009 INC-SPECT METH.1 - THERMAL NEUTRON FLUX = 5.0E+8/CM**2/SEC 2043800100010 (FAST COMPONENT ABOUT 1/10 OF THIS VALUE) 2043800100011 METH.2 - 3-DAYS IRRADIATION IN THERMAL NEUTRON 2043800100012 FLUX = 2.0E+13/CM**2/SEC. 2043800100013 SAMPLE METH.1 - TH-227 WAS MOUNTED IN THE FISSION COUNTER 2043800100014 WITH SCOTCH PLATE. 2043800100015 METH.2 - AN ELECTROPLATED SAMPLE WAS IRRADIATED. 2043800100016 .SEE TEXT FOR DETAIAL OF SAMPLE PREPARATION AND MASS 2043800100017 DETERMINATION OF TH-227. 2043800100018 METHOD - BACK TO BACK FISSION COUNTER METHOD (METH. 1) 2043800100019 - RADIOCHEMICAL TECHNIQUES (METH. 2) 2043800100020 DETECTOR (FISCH) PARALLEL PLATE-TYPE FISSION COUNTER OPERATED2043800100021 AS A GAS FLOW CHAMBER WITH AN ARGON(90 PERC.)-METHANE 2043800100022 MIXTURE. THIS COUNTER WAS FASTENED BACK TO BACK TO 2043800100023 A SIMILAR COUNTER CONTAINING A VERY THIN DEPOSIT OF 2043800100024 U-235 SERVING AS A MONITOR. (METH. 1) 2043800100025 (NAICR) (3 IN.* 3 IN.)NAI(TL) CRYSTAL. 2043800100026 STATUS DATUM TAKEN FROM THE PUBLICATION. 2043800100027 HISTORY (700626C) 2043800100028 (720320A) COMMENTS ADAPTED. 2043800100029 (751126E) 2043800100030 ERR-ANALYS METH.1 - ERRORS DUE TO THE DETERMINATION OF THE N.OF 2043800100031 ATOMS OF TH-227,THE BACKGROUND, THE U-235 2043800100032 FISSION CROSS-SECT. AND COUNT RATE, 2043800100033 AND STATISTICAL ERRORS WERE INCLUDED 2043800100034 METH.2 - NO ERROR GIVEN,BUT ESTIMATED TO 25-30 PERC. 2043800100035 FOR VARIOUS MEASUREMENTS. A STANDARD 2043800100036 DEVIATION OF 25 PERCENT HAS RESULTED FOR 2043800100037 THE ARITHMETIC MEAN. 2043800100038 THE STANDARD DEVIATION OF THE WEIGHTED MEAN INCLUDING 2043800100039 BOTH METHODS WAS ESTIMATED 10 PERCENT. 2043800100040 ENDBIB 38 0 2043800100041 NOCOMMON 0 0 2043800100042 ENDSUBENT 41 0 2043800199999 SUBENT 20438002 19840118 00002043800200001 BIB 5 10 2043800200002 REACTION (90-TH-227(N,F),,SIG) 2043800200003 MONITOR (92-U-235(N,F),,SIG) 2043800200004 THERMAL = 580 B. 2043800200005 PART-DET (FF,B-) FISSION FRAGMENTS AND DECAY BETA. 2043800200006 COMMENT THE RESULT IS IN DISAGREEMENT WITH THE VALUE OF 2043800200007 1500 +- 1000 BARNS, PETERSON ET AL. CITED IN BNL325 2043800200008 2ND EDITION (1968). 2043800200009 HISTORY (700626C) 2043800200010 (720320A) COMMENTS ADAPTED. 2043800200011 (751126E) 2043800200012 ENDBIB 10 0 2043800200013 NOCOMMON 0 0 2043800200014 DATA 3 1 2043800200015 EN-DUMMY DATA DATA-ERR 2043800200016 MEV B B 2043800200017 2.5300E-08 2.0000E+02 2.0000E+01 2043800200018 ENDDATA 3 0 2043800200019 ENDSUBENT 18 0 2043800299999 ENDENTRY 2 0 2043899999999