ENTRY 21718 19810723 00002171800000001 SUBENT 21718001 19810723 00002171800100001 BIB 13 36 2171800100002 INSTITUTE (2BLGGHT) INSTITUTE FOR NUCLEAR SCIENCES. 2171800100003 (2BLGMOL) REACTOR SITE. 2171800100004 REFERENCE (J,RCA,19,(3),102,72) FULL REPORT. 2171800100005 AUTHOR (P.DE REGGE,R.DAMS,J.HOSTE) 2171800100006 TITLE -THE MEAN FISSION NEUTRON CROSS SECTION FOR THE 2171800100007 REACTION TA-181(N,P)HF-181 -. 2171800100008 FACILITY (REAC )BR-2 REACTOR S.C.K.MOL. 2171800100009 INC-SOURCE (REAC ) REACTOR NEUTRONS, IRRADIATION FOR 98HRS. 2171800100010 INC-SPECT .EQUIVALENT FISSION NEUTRON SPECTRUM. 2171800100011 THE FAST NEUTRON SPECTRUM WAS MONITORED BY ALUMINIUM 2171800100012 AND MAGNESIUM THRESHOLD MONITORS. 2171800100013 SAMPLE .SPEC-PURE TA2O5, WITH A HAFNIUM IMPURITY OF 30 PPM. 2171800100014 PURIFIED TO REMOVE HAFNIUM BY A LIQUID EXTRACTION 2171800100015 TECHNIQUE BY MORRISON AND FREISER, REDUCING THE 2171800100016 HAFNIUM IMPURITY TO LESS THAN 0.5 PPM. 2171800100017 .THREE SAMPLES OF 10 MG WERE SEALED IN SILICA AND 2171800100018 IRRADIATED WITH AND WITHOUT CADMIUM COVER. 2171800100019 METHOD (ACTIV) ACTIVATION OF HF-181. REACTION PRODUCTS WERE 2171800100020 CHEMICALLY SEPERATED AFTER IRRADIATION USIND DOWEX 2171800100021 EXCHANGE RESIN TO SEPERATE TANTALUM AND HAFNIUM. 2171800100022 THE SEPERATED AND PURIFIED HAFNIUM FRACTION STILL 2171800100023 CONTAINED SOME TA-182 AS BACKGROUND, ELIMINATED BY 2171800100024 A FAST-SLOW COINCIDENCE COUNTING METHOD. 2171800100025 DETECTOR (GELI ) NO DETAILS. 2171800100026 MONITOR (13-AL-27(N,A)11-NA-24,,SIG,,FIS) FISSION SPECTRUM 2171800100027 AVERAGE VALUE TAKEN AS 0.60 MICRO-B. ALSO NI-58(N,P), 2171800100028 MG-24(N,P), AND NI-58(N,2N) WERE ALSO USED AS FAST 2171800100029 FLUX MONITORS WITH VALUES OF 102., 1.31, AND 0.0045 M 2171800100030 RESPECTIVELY. 2171800100031 .THE THERMAL FLUX WAS MONITORED BY THE CO-59(N,G) 2171800100032 REACTION WITH AN ASSUMED EFFECTIVE THERMAL CROSS 2171800100033 SECTION OF 37.9 B. 2171800100034 .THE CADMIUM RATIO WAS 40.2 . 2171800100035 STATUS .TEXT, PAGE 105, RCA,19,3,102. 2171800100036 HISTORY (810112C) 2171800100037 (810120E) 2171800100038 ENDBIB 36 0 2171800100039 COMMON 2 3 2171800100040 EN-DUMMY MONIT 2171800100041 MEV MB 2171800100042 1.5000E+00 6.0000E-01 2171800100043 ENDCOMMON 3 0 2171800100044 ENDSUBENT 43 0 2171800199999 SUBENT 21718002 19810120 00002171800200001 BIB 7 19 2171800200002 REACTION (73-TA-181(N,P)72-HF-181,,SIG,,FIS) FISSION SPECTRUM 2171800200003 AVERAGE CROSS SECTION. 2171800200004 ANALYSIS .IRRADIATION WITH AND WITHOUT CADMIUM COVER ALLOWS 2171800200005 THE HF-181 ACTIVITIES FROM HF-180(N,G) AND TA-181(N,P 2171800200006 TO BE SEPERATED. 2171800200007 DECAY-DATA (72-HF-181,42.5D,DG,133.,,DG,346.,,DG,482.) 2171800200008 FAST-SLOW COINCIDENCE ON THE 133 AND 482 KEV PHOTOPEAK2171800200009 BECAUSE OF LARGE DIFFERENCES IN SPECIFIC ACTIVITY WITH2171800200010 AND WITHOUT CADMIUM, AN INTERMEDIATE HF-181 REFERENCE 2171800200011 WAS USED. 2171800200012 STATUS .TEXT, PAGE 105. 2171800200013 HISTORY (810112C) 2171800200014 (810120E) 2171800200015 CORRECTION .CORRECTED FOR NEUTRON CAPTURE IN TRACE IMPURITY 2171800200016 OF HAFNIUM, SEE ANALYSIS. 2171800200017 ERR-ANALYS (ERR-S) ONE STANDARD DEVIATION, MAINLY DUE TO COUNTING 2171800200018 STATISTICS ON THE VERY LOW ACTIVITIES. SYSTEMATIC OR 2171800200019 RANDOM ERRORS IN THE FLUX DETERMINATIONS ARE NOT 2171800200020 REFLECTED IN THIS ERROR. 2171800200021 ENDBIB 19 0 2171800200022 NOCOMMON 0 0 2171800200023 DATA 2 1 2171800200024 DATA ERR-S 2171800200025 MB MB 2171800200026 1.2000E-03 3.0000E-04 2171800200027 ENDDATA 3 0 2171800200028 ENDSUBENT 27 0 2171800299999 ENDENTRY 2 0 2171899999999