ENTRY 12337 20170824 14331233700000001 SUBENT 12337001 20170824 14331233700100001 BIB 11 55 1233700100002 TITLE Multiplicities of Fission Neutrons 1233700100003 AUTHOR (B.C.Diven,H.C.Martin,R.F.Taschek,J.Terrell) 1233700100004 REFERENCE (J,PR,101,1012,1956) 1233700100005 #doi:10.1103/PhysRev.101.1012 1233700100006 INSTITUTE (1USALAS) 1233700100007 DETECTOR (STANK,FISCH) The scintillator tank is a cylinder 30 1233700100008 in. long and 28.5 in. in diameter with 0.25-in. thick 1233700100009 steel walls, coated on the inside with 1233700100010 light-reflecting paint. 1233700100011 MONITOR (92-U-235(N,F),PR,NU) Normalized to U-235 prompt nu. 1233700100012 METHOD (COINC) A 10-channel pulse-height analyzer is used to 1233700100013 select a bias for the fission counter which is low 1233700100014 enough to accept nearly all fission events but high 1233700100015 enough to discriminate against alpha particles. About 1233700100016 1500 pairs of fission-triggered and background sweeps 1233700100017 are then recorded photographically on a roll of film. 1233700100018 The minimum acceptable height of neutron pulses is 1233700100019 also marked on the table. In order to avoid sweeps 1233700100020 triggered by events other than fission, only those 1233700100021 traces are read which have a properly located prompt 1233700100022 pulse due to fission gammas and proton recoils; at 1233700100023 least 99 percent of the fission events produce such a 1233700100024 pulse. The number of acceptable pulses after the 1233700100025 prompt-pulse time from each fission and background 1233700100026 trace are then recorded. Such measurements have been 1233700100027 made for fission induced by thermal neutrons and by 1233700100028 80-keV neutrons in U233, U235, and Pu239 and for 1233700100029 spontaneous fission of Pu240, Cm244 and Cf252. To 1233700100030 deduce the emission probabilities, Pn, from the 1233700100031 various numbers of pulses per sweep, it is necessary 1233700100032 to know the efficiency of the detector for fission 1233700100033 neutrons. The experimental efficiencies obtained were 1233700100034 87(2) percent and 85(3) percent, respectively, for 1233700100035 neutrons with energies of 0 to 100 keV and 2 MeV. If 1233700100036 it is assumed that neutron leakage is the primary 1233700100037 reason for change in efficiency with energy, the 1233700100038 Monte Carlo calculations may be used to plot a smooth 1233700100039 curve of efficiency versus energy passing through the 1233700100040 two experimental points. For fission-spectrum 1233700100041 neutrons the average efficiency thus determined is 1233700100042 83(2) percent. 1233700100043 ERR-ANALYS (DATA-ERR) The errors shown are standard deviations. 1233700100044 Allowance has been made for counting statistics, 1233700100045 uncertainty in the efficiency, and uncertainty in the 1233700100046 coincidence correction. 1233700100047 COMMENT Thermal neutron data have been omitted because of the 1233700100048 greater weight of the 80-keV data; there was no 1233700100049 significant difference. 1233700100050 STATUS (TABLE) Table II, page 1015. 1233700100051 HISTORY (19760804T) Translated from SCISRS 1233700100052 (19841005A) converted to reaction formalism 1233700100053 (20170824A) BP: Updated to new date formats,lower case.1233700100054 Corrections according last EXFOR rules and 1233700100055 Dict., added doi and fission neutron 1233700100056 multiplicity distribution data. 1233700100057 ENDBIB 55 0 1233700100058 COMMON 3 3 1233700100059 EN-NRM MONIT MONIT-ERR 1233700100060 EV PRT/FIS PRT/FIS 1233700100061 0.0253 2.46 0.03 1233700100062 ENDCOMMON 3 0 1233700100063 ENDSUBENT 62 0 1233700199999 SUBENT 12337002 20170824 14331233700200001 BIB 4 5 1233700200002 REACTION (92-U-233(N,F),PR,NU) 1233700200003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233700200004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233700200005 the target. 1233700200006 HISTORY (20170824A) BP: Corrected units. 1233700200007 ENDBIB 5 0 1233700200008 NOCOMMON 0 0 1233700200009 DATA 3 1 1233700200010 EN DATA DATA-ERR 1233700200011 MEV PRT/FIS PRT/FIS 1233700200012 8.0E-02 2.585 6.2E-02 1233700200013 ENDDATA 3 0 1233700200014 ENDSUBENT 13 0 1233700299999 SUBENT 12337003 20170824 14331233700300001 BIB 5 6 1233700300002 REACTION (92-U-235(N,F),PR,NU) 1233700300003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233700300004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233700300005 the target. 1233700300006 COMMENT Normalizing value. 1233700300007 HISTORY (20170824A) BP: Corrected units. 1233700300008 ENDBIB 6 0 1233700300009 NOCOMMON 0 0 1233700300010 DATA 3 1 1233700300011 EN DATA DATA-ERR 1233700300012 MEV PRT/FIS PRT/FIS 1233700300013 8.0E-02 2.47 3.0E-02 1233700300014 ENDDATA 3 0 1233700300015 ENDSUBENT 14 0 1233700399999 SUBENT 12337004 20170824 14331233700400001 BIB 4 5 1233700400002 REACTION (94-PU-239(N,F),PR,NU) 1233700400003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233700400004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233700400005 the target. 1233700400006 HISTORY (20170824A) BP: Corrected units. 1233700400007 ENDBIB 5 0 1233700400008 NOCOMMON 0 0 1233700400009 DATA 3 1 1233700400010 EN DATA DATA-ERR 1233700400011 MEV PRT/FIS PRT/FIS 1233700400012 8.0E-02 3.048 7.9E-02 1233700400013 ENDDATA 3 0 1233700400014 ENDSUBENT 13 0 1233700499999 SUBENT 12337005 20170824 14331233700500001 BIB 2 3 1233700500002 REACTION (94-PU-240(0,F),,NU) 1233700500003 HISTORY (19800512A) Iso-quant corrected to nuc-quant 1233700500004 (20170824A) BP: Corrected units. 1233700500005 ENDBIB 3 0 1233700500006 NOCOMMON 0 0 1233700500007 DATA 2 1 1233700500008 DATA DATA-ERR 1233700500009 PRT/FIS PRT/FIS 1233700500010 2.257 0.045 1233700500011 ENDDATA 3 0 1233700500012 ENDSUBENT 11 0 1233700599999 SUBENT 12337006 20170824 14331233700600001 BIB 2 3 1233700600002 REACTION (96-CM-244(0,F),,NU) 1233700600003 HISTORY (19800512A) Iso-quant corrected to nuc-quant 1233700600004 (20170824A) BP: Corrected units. 1233700600005 ENDBIB 3 0 1233700600006 NOCOMMON 0 0 1233700600007 DATA 2 1 1233700600008 DATA DATA-ERR 1233700600009 PRT/FIS PRT/FIS 1233700600010 2.810 0.059 1233700600011 ENDDATA 3 0 1233700600012 ENDSUBENT 11 0 1233700699999 SUBENT 12337007 20170824 14331233700700001 BIB 2 3 1233700700002 REACTION (98-CF-252(0,F),PR,NU) 1233700700003 HISTORY (19800512A) Iso-quant corrected to nuc-quant 1233700700004 (20170824A) BP: Corrected units and reaction. 1233700700005 ENDBIB 3 0 1233700700006 NOCOMMON 0 0 1233700700007 DATA 2 1 1233700700008 DATA DATA-ERR 1233700700009 PRT/FIS PRT/FIS 1233700700010 3.869 0.078 1233700700011 ENDDATA 3 0 1233700700012 ENDSUBENT 11 0 1233700799999 SUBENT 12337008 20170824 14331233700800001 BIB 4 5 1233700800002 REACTION (92-U-233(N,F),PR/NUM,NU) 1233700800003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233700800004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233700800005 the target. 1233700800006 HISTORY (20170824C) BP 1233700800007 ENDBIB 5 0 1233700800008 COMMON 1 3 1233700800009 EN 1233700800010 KEV 1233700800011 80.0 1233700800012 ENDCOMMON 3 0 1233700800013 DATA 3 9 1233700800014 PART-OUT DATA DATA-ERR 1233700800015 NO-DIM NO-DIM NO-DIM 1233700800016 0. 0.010 0.008 1233700800017 1. 0.151 0.024 1233700800018 2. 0.326 0.037 1233700800019 3. 0.301 0.044 1233700800020 4. 0.176 0.041 1233700800021 5. 0.042 0.028 1233700800022 6. -0.010 0.017 1233700800023 7. 0.006 0.009 1233700800024 8. -0.002 0.002 1233700800025 ENDDATA 11 0 1233700800026 ENDSUBENT 25 0 1233700899999 SUBENT 12337009 20170824 14331233700900001 BIB 4 5 1233700900002 REACTION (92-U-235(N,F),PR/NUM,NU) 1233700900003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233700900004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233700900005 the target. 1233700900006 HISTORY (20170824C) BP 1233700900007 ENDBIB 5 0 1233700900008 COMMON 1 3 1233700900009 EN 1233700900010 KEV 1233700900011 80.0 1233700900012 ENDCOMMON 3 0 1233700900013 DATA 3 9 1233700900014 PART-OUT DATA DATA-ERR 1233700900015 NO-DIM NO-DIM NO-DIM 1233700900016 0. 0.027 0.004 1233700900017 1. 0.158 0.010 1233700900018 2. 0.339 0.014 1233700900019 3. 0.305 0.015 1233700900020 4. 0.133 0.013 1233700900021 5. 0.038 0.009 1233700900022 6. -0.001 0.003 1233700900023 7. 0.001 0.002 1233700900024 8. 0.000 0.000 1233700900025 ENDDATA 11 0 1233700900026 ENDSUBENT 25 0 1233700999999 SUBENT 12337010 20170824 14331233701000001 BIB 4 5 1233701000002 REACTION (94-PU-239(N,F),PR/NUM,NU) 1233701000003 FACILITY (ACCEL,1USALAS) Electrostatic accelerator. 1233701000004 INC-SOURCE (P-T) 80-keV neutrons from the T(p,n)He3 reaction in 1233701000005 the target. 1233701000006 HISTORY (20170824C) BP 1233701000007 ENDBIB 5 0 1233701000008 COMMON 1 3 1233701000009 EN 1233701000010 KEV 1233701000011 80.0 1233701000012 ENDCOMMON 3 0 1233701000013 DATA 3 9 1233701000014 PART-OUT DATA DATA-ERR 1233701000015 NO-DIM NO-DIM NO-DIM 1233701000016 0. -0.01 0.01 1233701000017 1. 0.11 0.03 1233701000018 2. 0.13 0.06 1233701000019 3. 0.56 0.08 1233701000020 4. 0.11 0.08 1233701000021 5. 0.06 0.09 1233701000022 6. 0.05 0.08 1233701000023 7. 0.00 0.06 1233701000024 8. -0.01 0.03 1233701000025 ENDDATA 11 0 1233701000026 ENDSUBENT 25 0 1233701099999 SUBENT 12337011 20170824 14331233701100001 BIB 2 2 1233701100002 REACTION (94-PU-240(0,F),NUM,NU) 1233701100003 HISTORY (20170824C) BP 1233701100004 ENDBIB 2 0 1233701100005 NOCOMMON 0 0 1233701100006 DATA 3 9 1233701100007 PART-OUT DATA DATA-ERR 1233701100008 NO-DIM NO-DIM NO-DIM 1233701100009 0. 0.049 0.006 1233701100010 1. 0.214 0.012 1233701100011 2. 0.321 0.014 1233701100012 3. 0.282 0.017 1233701100013 4. 0.112 0.013 1233701100014 5. 0.021 0.008 1233701100015 6. 0.001 0.003 1233701100016 7. 0.000 0.002 1233701100017 8. 0.000 0.000 1233701100018 ENDDATA 11 0 1233701100019 ENDSUBENT 18 0 1233701199999 SUBENT 12337012 20170824 14331233701200001 BIB 2 2 1233701200002 REACTION (96-CM-244(0,F),NUM,NU) 1233701200003 HISTORY (20170824C) BP 1233701200004 ENDBIB 2 0 1233701200005 NOCOMMON 0 0 1233701200006 DATA 3 9 1233701200007 PART-OUT DATA DATA-ERR 1233701200008 NO-DIM NO-DIM NO-DIM 1233701200009 0. 0.009 0.005 1233701200010 1. 0.109 0.016 1233701200011 2. 0.292 0.023 1233701200012 3. 0.315 0.027 1233701200013 4. 0.224 0.027 1233701200014 5. 0.030 0.017 1233701200015 6. 0.021 0.010 1233701200016 7. 0.000 0.003 1233701200017 8. 0.000 0.000 1233701200018 ENDDATA 11 0 1233701200019 ENDSUBENT 18 0 1233701299999 SUBENT 12337013 20170824 14331233701300001 BIB 2 2 1233701300002 REACTION (98-CF-252(0,F),PR/NUM,NU) 1233701300003 HISTORY (20170824C) BP 1233701300004 ENDBIB 2 0 1233701300005 NOCOMMON 0 0 1233701300006 DATA 3 9 1233701300007 PART-OUT DATA DATA-ERR 1233701300008 NO-DIM NO-DIM NO-DIM 1233701300009 0. 0.005 0.002 1233701300010 1. 0.004 0.009 1233701300011 2. 0.138 0.019 1233701300012 3. 0.223 0.032 1233701300013 4. 0.356 0.035 1233701300014 5. 0.175 0.034 1233701300015 6. 0.071 0.028 1233701300016 7. 0.022 0.017 1233701300017 8. 0.006 0.007 1233701300018 ENDDATA 11 0 1233701300019 ENDSUBENT 18 0 1233701399999 ENDENTRY 13 0 1233799999999