ENTRY 12870 19840418 00001287000000001 SUBENT 12870001 19840418 00001287000100001 BIB 14 47 1287000100002 INSTITUTE (1USALRL) 1287000100003 REFERENCE (J,NSE,86,157,8402) 1287000100004 AUTHOR (R.E.HOWE) 1287000100005 TITLE MEASUREMENT OF FISSION NEUTRON MULTIPLICITIES FOR 1287000100006 THORIUM-232 AND URANIUM-235 WITH INCIDENT NEUTRON 1287000100007 ENERGIES TO 49 MEV. 1287000100008 FACILITY (LINAC) 1287000100009 METHOD (TOF) TIME OF FLIGHT 1287000100010 INC-SOURCE (EVAP)LINAC WAS PULSED 1440 TIMES PER/SEC WITH AN 1287000100011 ELECTRON PULSE WIDTH OF 7.0 NS. 1287000100012 WATER COOLED TANTALUM PLATES WERE USED FOR NEUTRON 1287000100013 PRODUCTION. 1287000100014 MONITOR INCIDENT NEUTRON ENERGY SCALE WAS CALIBRATED AGAINST 1287000100015 THE CARBON 2.007+-0.002 MEV RESONANCE AND PHOTO- 1287000100016 FISSION EVENTS WERE USED TO MARK THE TIME. 1287000100017 INC-SPECT 40 KEV AT 4 MEV AND 440 KEV AT 20 MEV. 1287000100018 THE EN-RSL GIVEN INCLUDES THE HWHM OF THE INCIDENT 1287000100019 NEUTRON ENERGY BIN INCLUDING DISPERSION DUE TO 1287000100020 FINITE TIME WIDTH OF ELECTRON BEAM. 1287000100021 DETECTOR (SCIN) LIQUID SCINTILLATOR 1287000100022 NEUTRONS WERE DETECTED IN A LIQUID SCINTILLATOR LOCATED1287000100023 NEAR THE FISSION CHAMBERS. 1287000100024 THE LIQUID SCINTILLATOR WAS CYLINDRICAL 7.5CM LONG 1287000100025 AND 12.5 CM IN DIAMETER. 1287000100026 (FISCH) 1287000100027 TH-232 FISSION CHAMBER WAS CONSTRUCTED FROM A SEQUENCE 1287000100028 OF 29 FOILS WITH 166 MG MASS 1287000100029 U-235 FISSION CHAMBER WAS CONSTRUCTED FROM A SEQUENCE 1287000100030 OF 11 FOILS WITH 66.3 MG MASS 1287000100031 EFFICIENCIES OF THE FISSION CHAMBERS WERE 95 PERCENT. 1287000100032 SAMPLE ALL SAMPLES WERE OF HIGH PURITY GREATER THAN 99.8 1287000100033 PERCENT. 1287000100034 UO2 WAS VAPOR DEPOSITED ON 2.5 MICRO M TO 500 MICRO 1287000100035 GM/CM2 1287000100036 THO2 WAS VAPOR DEPOSITED ON 2.5 MICRO M TO 500 MICRO 1287000100037 GM/CM2 1287000100038 ANALYSIS SIMILAR TO AUTHOR'S PAPER NUCL.SCI.ENG.77,454,1981. 1287000100039 ERR-ANALYS (ERR-S) STATISTICAL UNCERTAINTY. 1287000100040 THE STATISTICAL UNCERTAINTY INCLUDES UNCERTAINTIES IN 1287000100041 COINCIDENT NEUTRON COUNTS 1287000100042 TOTAL FISSION COUNTS 1287000100043 MEASURED DEAD TIMES 1287000100044 MEASURED BACKGROUNDS 1287000100045 (ERR-1) SYSTEMATIC UNCERTAINTY 1287000100046 (ERR-T) TOTAL UNCERTAINTY 1287000100047 R.M.S. VALUE OF STATISTICAL AND SYSTEMATIC ERRORS.1287000100048 HISTORY (840417C) 1287000100049 ENDBIB 47 0 1287000100050 NOCOMMON 0 0 1287000100051 ENDSUBENT 50 0 1287000199999 SUBENT 12870002 19840418 00001287000200001 BIB 4 19 1287000200002 REACTION ((90-TH-232(N,F),PR,NU)/(92-U-235(N,F),PR,NU)) 1287000200003 ANALYSIS THE RATIO WAS COMPUTED BY DIVIDING THE RAW NU-PROMPT 1287000200004 DATA FOR TH-232 BY THAT FOR U-235. 1287000200005 CORRECTION THE FOLLOWING CORRECTIONS WERE MADE FOR THE RATIO 1287000200006 BACCGROUND NEUTRONS 3.1 PERCENT AT 3.1 MEV 1287000200007 ENERGY-INDEPENDENT PROPAGATION-DELAY 1287000200008 INDUCED EFFFICIENCY 4.8+-0.6 PERCENT. 1287000200009 GEOMETRY DEPENDENT EFFICIENCY DIFFERNCES BETWEEN 1287000200010 TWO NUCLIDE SAMPLES 0.34+-0.19PERCENT. 1287000200011 PILE-UP INDUCED DEAD TIME 0. 1287000200012 ENERGY-DEPENDENT DEAD-TIME 1287000200013 2.3 PERCENT AT 2. MEV 1287000200014 4.2 PERCENT AT 15. MEV 1287000200015 8.7 PERCENT AT 49. MEV. 1287000200016 CHANGES IN EMITTED NEUTRON SPECTRUM 1287000200017 3.0 PERCENT BELOW 25.MEV 1287000200018 6.0 PERCENT AT 49. MEV 1287000200019 STATUS DATA TAKEN FROM TABLE I OF THE JOURNAL ARTICLE. 1287000200020 (APRVD) R.E.HOWE, 84/6/13. 1287000200021 ENDBIB 19 0 1287000200022 NOCOMMON 0 0 1287000200023 DATA 6 40 1287000200024 EN EN-RSL DATA ERR-S ERR-1 ERR-T 1287000200025 MEV MEV NO-DIM NO-DIM NO-DIM NO-DIM 1287000200026 1.084 0.048 1.09 0.18 0.015 0.18 1287000200027 1.163 0.053 0.96 0.15 0.012 0.15 1287000200028 1.250 0.059 0.997 0.064 0.0082 0.065 1287000200029 1.348 0.066 0.836 0.035 0.0063 0.036 1287000200030 1.458 0.075 0.787 0.026 0.012 0.029 1287000200031 1.581 0.084 0.802 0.024 0.015 0.028 1287000200032 1.721 0.096 0.850 0.026 0.012 0.029 1287000200033 1.88 0.11 0.834 0.025 0.0054 0.026 1287000200034 2.06 0.13 0.871 0.025 0.0075 0.026 1287000200035 2.27 0.15 0.839 0.024 0.0072 0.025 1287000200036 2.52 0.17 0.873 0.034 0.0070 0.035 1287000200037 2.72 0.12 0.831 0.034 0.0066 0.035 1287000200038 2.88 0.13 0.810 0.034 0.0065 0.035 1287000200039 3.04 0.14 0.796 0.034 0.0064 0.035 1287000200040 3.23 0.15 0.813 0.034 0.0065 0.035 1287000200041 3.43 0.16 0.831 0.035 0.0066 0.036 1287000200042 3.65 0.18 0.827 0.034 0.0066 0.035 1287000200043 3.89 0.20 0.825 0.035 0.0066 0.036 1287000200044 4.16 0.22 0.809 0.032 0.0065 0.033 1287000200045 4.45 0.24 0.842 0.034 0.0067 0.035 1287000200046 4.78 0.27 0.836 0.032 0.0067 0.033 1287000200047 5.14 0.30 0.791 0.030 0.0064 0.031 1287000200048 5.55 0.34 0.838 0.032 0.0067 0.033 1287000200049 6.01 0.38 0.867 0.028 0.0069 0.029 1287000200050 6.53 0.43 0.878 0.025 0.012 0.028 1287000200051 7.11 0.49 0.897 0.023 0.013 0.026 1287000200052 7.78 0.56 0.932 0.024 0.011 0.026 1287000200053 8.55 0.65 0.896 0.025 0.0090 0.027 1287000200054 9.45 0.75 0.882 0.026 0.0071 0.027 1287000200055 10.48 0.88 0.870 0.027 0.0057 0.028 1287000200056 11.7 1.0 0.857 0.030 0.0054 0.030 1287000200057 13.2 1.2 0.897 0.032 0.0072 0.033 1287000200058 14.9 1.5 0.953 0.034 0.0076 0.035 1287000200059 17.0 1.8 0.883 0.034 0.0059 0.035 1287000200060 19.6 2.2 0.885 0.036 0.0059 0.036 1287000200061 22.8 2.8 0.900 0.038 0.0059 0.038 1287000200062 26.9 3.6 0.944 0.042 0.0062 0.042 1287000200063 32.2 4.7 0.956 0.044 0.0063 0.044 1287000200064 39.2 6.3 1.048 0.056 0.0069 0.056 1287000200065 48.9 8.7 1.009 0.070 0.0066 0.070 1287000200066 ENDDATA 42 0 1287000200067 ENDSUBENT 66 0 1287000299999 SUBENT 12870003 19840418 00001287000300001 BIB 6 24 1287000300002 REACTION (90-TH-232(N,F),PR,NU) 1287000300003 MONITOR (92-U-235(N,F),PR,NU) MANERO-KONSHIN DATA. 1287000300004 AVERAGE SCINTILLATOR EFFICIENCY IN THE RANGE OF 1287000300005 1. TO 15. MEV WAS USED TO NORMALIZE THE ABSOLUTE 1287000300006 NUBAR DATA. THIS WAS DETERMINED BY COMPARING THE 1287000300007 U-235 DATA BETWEEN 1. AND 15. MEV WITH THE 1287000300008 RENORMALIZED MANERO-KONSHIN,AT.ENERGY REV.,10,637, 1287000300009 1972 U-235 NUBAR VALUES TO CF-252 NUBAR-PROMPT 1287000300010 VALUE=3.757. 1287000300011 CORRECTION THE CORRECTION FOR- 1287000300012 BACKGROUND NEUTRONS 6.0+-0.7 PERCENT. 1287000300013 ANGULAR ANISOTROPY AT WORST6.7 PERCENT 1287000300014 ABOVE 20 MEV 2.O PERCENT 1287000300015 FORWARD PEAKING 1.0 PERCENT 1287000300016 ERR-ANALYS SYSTEMATIC UNCERTAINTIES ARE BASED ON- 1287000300017 GEOMETRICAL EFFICENCY CORRECTION =.19PERCENT1287000300018 PROPAGATION-DELAY DIFFERENCE CORRECTION =.6PERCENT1287000300019 UNDETECED PILE-UP NEUTRON CORRECTION 1287000300020 DETECTED NEUTRON ANISOTROPY CORRECTION 1287000300021 ADD-RES THE PROMPT-NUBAR SLOPE WITH RESPECT TO NEUTRON ENERGY 1287000300022 =9. MEV IN THE 15. TO 49. MEV RANGE. 1287000300023 STATUS DATA TAKEN FROM TABLE II OF THE JOURNAL ARTICLE. 1287000300024 (DEP,12870002) 1287000300025 (DEP,12870004) 1287000300026 ENDBIB 24 0 1287000300027 COMMON 2 3 1287000300028 EN-NRM-MIN EN-NRM-MAX 1287000300029 MEV MEV 1287000300030 1. 15. 1287000300031 ENDCOMMON 3 0 1287000300032 DATA 6 7 1287000300033 EN EN-RSL DATA ERR-S ERR-1 ERR-T 1287000300034 MEV MEV NO-DIM NO-DIM NO-DIM NO-DIM 1287000300035 17.0 1.8 4.40 0.14 0.062 0.15 1287000300036 19.6 2.2 4.87 0.16 0.073 0.18 1287000300037 22.8 2.8 4.99 0.17 0.085 0.19 1287000300038 26.9 3.6 5.89 0.20 0.11 0.23 1287000300039 32.2 4.7 6.37 0.22 0.13 0.25 1287000300040 39.2 6.3 7.21 0.27 0.17 0.32 1287000300041 48.9 8.7 7.85 0.36 0.22 0.42 1287000300042 ENDDATA 9 0 1287000300043 ENDSUBENT 42 0 1287000399999 SUBENT 12870004 19840418 00001287000400001 BIB 6 22 1287000400002 REACTION (92-U-235(N,F),PR,NU) 1287000400003 MONITOR (92-U-235(N,F),PR,NU) MANERO-KONSHIN DATA. 1287000400004 AVERAGE SCINTILLATOR EFFICIENCY IN THE RANGE OF 1287000400005 1. TO 15. MEV WAS USED TO NORMALIZE THE ABSOLUTE 1287000400006 NUBAR DATA. THIS WAS DETERMINED BY COMPARING THE 1287000400007 U-235 DATA BETWEEN 1. AND 15. MEV WITH THE 1287000400008 RENORMALIZED MANERO-KONSHIN,AT.ENERGY REV.,10,637, 1287000400009 1972 U-235 NUBAR VALUES TO CF-252 NUBAR-PROMPT 1287000400010 VALUE=3.757. 1287000400011 CORRECTION THE CORRECTION FOR- 1287000400012 BACKGROUND NEUTRONS 6.0+-0.7 PERCENT. 1287000400013 ANGULAR ANISOTROPY AT WORST6.7 PERCENT 1287000400014 ABOVE 20 MEV 2.O PERCENT 1287000400015 FORWARD PEAKING 1.0 PERCENT 1287000400016 ERR-ANALYS SYSTEMATIC UNCERTAINTIES ARE BASED ON- 1287000400017 GEOMETRICAL EFFICENCY CORRECTION =.19PERCENT1287000400018 PROPAGATION-DELAY DIFFERECNCE CORRECTION=.6PERCENT1287000400019 UNDETECED PILE-UP NEUTRON CORRECTION 1287000400020 DETECTED NEUTRON ANISOTROPY CORRECTION 1287000400021 ADD-RES THE PROMPT-NUBAR SLOPE WITH RESPECT TO NEUTRON ENERGY 1287000400022 =11. MEV IN THE 17. TO 49. MEV RANGE. 1287000400023 STATUS DATA TAKEN FROM TABLE III OF THE JOURNAL ARTICLE. 1287000400024 ENDBIB 22 0 1287000400025 COMMON 2 3 1287000400026 EN-NRM-MIN EN-NRM-MAX 1287000400027 MEV MEV 1287000400028 1. 15. 1287000400029 ENDCOMMON 3 0 1287000400030 DATA 6 7 1287000400031 EN EN-RSL DATA ERR-S ERR-1 ERR-T 1287000400032 MEV MEV NO-DIM NO-DIM NO-DIM NO-DIM 1287000400033 17.0 1.8 4.98 0.10 0.065 0.12 1287000400034 19.6 2.2 5.50 0.11 0.077 0.13 1287000400035 22.8 2.8 5.54 0.14 0.089 0.17 1287000400036 26.9 3.6 6.24 0.17 0.11 0.20 1287000400037 32.2 4.7 6.66 0.19 0.13 0.23 1287000400038 39.2 6.3 6.88 0.28 0.16 0.32 1287000400039 48.9 8.7 7.78 0.44 0.21 0.49 1287000400040 ENDDATA 9 0 1287000400041 ENDSUBENT 40 0 1287000499999 SUBENT 12870005 19840918 00001287000500001 BIB 5 16 1287000500002 REACTION (90-TH-231(N,F),PR,NU,,,DERIV) 1287000500003 ANALYSIS THE TH-232 NUBAR-PROMPT RESULTS ABOVE THE (N,NF) 1287000500004 THRESHOLD WAS USED TO ESTIMATE THE TH-231 1287000500005 PROMPT-NUBAR VALUES AS A FUNCTION OF NEUTRON ENERGY. 1287000500006 MONITOR (98-CF-252(N,F),PR,NU) 1287000500007 (92-U-235(N,F),PR,NU) MANERO-KONSHIN DATA. 1287000500008 AVERAGE SCINTILLATOR EFFICIENCY IN THE RANGE OF 1287000500009 1. TO 15. MEV WAS USED TO NORMALIZE THE ABSOLUTE 1287000500010 NUBAR DATA. THIS WAS DETERMINED BY COMPARING THE 1287000500011 U-235 DATA BETWEEN 1. AND 15. MEV WITH THE 1287000500012 RENORMALIZED MANERO-KONSHIN,AT.ENERGY REV.,10,637, 1287000500013 1972 U-235 NUBAR VALUES TO CF-252 NUBAR-PROMPT 1287000500014 VALUE=3.757. 1287000500015 STATUS (DEP,12870002) 1287000500016 (DEP,12870003) 1287000500017 HISTORY (840918A) BIB CORRECTION. 1287000500018 ENDBIB 16 0 1287000500019 NOCOMMON 0 0 1287000500020 DATA 3 1 1287000500021 EN DATA ERR-T 1287000500022 EV NO-DIM NO-DIM 1287000500023 0.0253 2.6 0.3 1287000500024 ENDDATA 3 0 1287000500025 ENDSUBENT 24 0 1287000599999 ENDENTRY 5 0 1287099999999