ENTRY 10906 19840622 00001090600000001 SUBENT 10906001 19840622 00001090600100001 BIB 15 65 1090600100002 INSTITUTE (1USAORL) 1090600100003 REFERENCE (R,ORNL-TM-8203,8310) 1090600100004 AUTHOR (D.C.LARSON,N.M.LARSON,J.A.HARVEY,N.W.HILL,C.H.JOHNSON)1090600100005 TITLE APPLICATION OF NEW TECHNIQUES TO ORELA NEUTRON 1090600100006 TRANSMISSION MEASUREMENTS AND THEIR UNCERTAINTY 1090600100007 ANALYSIS-THE CASE OF NATURAL NICKEL FROM 2 KEV TO 1090600100008 20 MEV. 1090600100009 FACILITY (LINAC) ORELA 1090600100010 METHOD (TOF)200-M FLIGHT PATH 1090600100011 INC-SOURCE (PHOTO)REPETITION RATE OF 780 HZ AT ELECTRON BURST 1090600100012 WIDTH OF 7.5+-0.5 NS WITH 8KW ON THE TARGET. 1090600100013 MONITOR 235-U FISSION CHAMBER WITH 89 MG OF 235-U. 1090600100014 DETECTOR (SCIN) 1.9CM BY 10.2 CM DIAMETER NE110 PLASTIC 1090600100015 SCINTILLATOR, COUPLED TO A RCA-8854 PHOTOTUBE. 1090600100016 SAMPLE 1820-G NATURAL NICKEL CYLINDRICAL IN SHAPE WITH 10.2 1090600100017 CM DIAMETER AND 2.54 CM LENGTH. 1090600100018 SAMPLE THICKNESS=0.2304 ATOMS/BARN. 1090600100019 NATURAL NICKEL CONSISTED OF- 1090600100020 . NICKEL 99.97 PERCENT 1090600100021 . COBALT-LESS THAN 0.001 PERCENT 1090600100022 . CARBON-LESS THAN 0.02 PERCENT 1090600100023 . IRON 0.005 1090600100024 . OTHERS-LESS THAN 0.001 PERCENT 1090600100025 ANALYSIS AFTER CORRECTING THE DATA FOR BACKGROUND EFFECTS - 1090600100026 . REGIONS OF EACH BIAS SPECTRUM WERE SELECTED, BASED 1090600100027 ON TOTAL COUNTS AND COUNT-TO-BACKGROUND RATIO, 1090600100028 AND SUMMED TO FORM THE FINAL SPECTRA FOR BOTH 1090600100029 SAMPLE-IN AND SAMPLE-OUT. 1090600100030 . SAMPLE-IN AND SAMPLE-OUT SPECTRA WERE NORMALIZED TO 1090600100031 THE HOUSE. MONITOR COUNTER. FINALLY THE RATIOS WERE 1090600100032 CONVERTED TO CROSS SECTION AS A FUNCTION OF ENERGY. 1090600100033 . FINALLY SAMPLE-IN AND SAMPLE-OUT COUNTS WERE 1090600100034 AVERAGED TO REDUCE THE NUMBER OF DATA POINTS FROM 1090600100035 60000 TO 13695. 1090600100036 ERR-ANALYS (ERR-S) STATISTICAL UNCERTAINTY 1090600100037 (ERR-1) SYSTEMATIC UNCERTAINTY 1090600100038 CHANNEL INDEPENDENT 1090600100039 .SAMPLE THICKNESS UNCERTAINTY = 0.18 PERCENT 1090600100040 .DUE TO MONITOR COUNTER = 0.3 PERCENT (SAMPLE IN)1090600100041 0.5 PERCENT(SAMPLE OUT)1090600100042 CHANNEL DEPENDENT- 1090600100043 . ENERGY SCALE UNCERTAINTY=SEE ORNL/TM-8880(84)1090600100044 . DEADTIME UNCERTAINTY 1090600100045 . BACKGROUND UNCERTAINTIES. 1090600100046 (ERR-T) TOTAL UNCERTAINTY 1090600100047 AVERAGED OVER THE ENTIRE ENERGY RANGE THE STATISTICAL 1090600100048 UNCERTAINTY IS 2.5 TIMES LARGER THAN THE SYSTEMATIC 1090600100049 UNCERTAINTIES. 1090600100050 . CROSS SECTION UNCERTAINTIES AND CORRELATIONS HAVE 1090600100051 BEEN DISCUSSED IN DETAIL IN THE ORNL REPORT. 1090600100052 AT LOW ENERGIES SOME OF THE ERRORS ARE EXTREMELY LARGE 1090600100053 DUE TO LARGE BLACKING OUT RESONANCES. 1090600100054 CORRECTION FOLLOWING CORRECTIONS WERE MADE - 1090600100055 . DEADTIME CORRECTION 1090600100056 LARGEST CORRECTION WAS AROUND 1 MEV 1090600100057 1.23 AND 1.56 FACTORS FOR SAMPLE-IN AND 1090600100058 SAMPLE-OUT SPECTRA RESPECTIVELY. 1090600100059 . BACKGROUND CORRECTION 1090600100060 TIME-INDEPENDENT 1090600100061 2.2 MEV GAMMA-RAY BACKGROUND 1090600100062 B-10(N,ALPHA-GAMMA) REACTION 1090600100063 OTHER SOURCES 1090600100064 STATUS (PRELM) PRIVATE COMMUNICATION 84/6/8. 1090600100065 (APRVD) D.C.LARSON, 84/7/20. 1090600100066 HISTORY (840621C) 1090600100067 ENDBIB 65 0 1090600100068 NOCOMMON 0 0 1090600100069 ENDSUBENT 68 0 1090600199999 SUBENT 10906002 19861118 00001090600200001 BIB 3 3 1090600200002 REACTION (28-NI-0(N,TOT),,SIG) 1090600200003 STATUS (SPSDD,12882010) 1090600200004 HISTORY (861118A) STATUS SPSDD ADDED. 1090600200005 ENDBIB 3 0 1090600200006 NOCOMMON 0 0 1090600200007 NODATA 0 0 1090600200008 ENDSUBENT 7 0 1090600299999 ENDENTRY 2 0 1090699999999