ENTRY 14297 20240710 1429700000001 SUBENT 14297001 20240710 20240316 1429700100001 BIB 9 36 1429700100002 TITLE Numbers of Prompt Neutrons per Fission for U233, U235, 1429700100003 Pu239 and Cf252 1429700100004 AUTHOR (B.C.Diven,J.C.Hopkins) 1429700100005 REFERENCE (C,61VIENNA,1,149,1961) 1429700100006 INSTITUTE (1USALAS) 1429700100007 FACILITY (VDG,1USALAS) 1429700100008 DETECTOR (SCIN,FISCH) Large cadmium-loaded liquid scintillator 1429700100009 and fission counter. 1429700100010 METHOD (REC,COINC) In order to deduced the mean number of 1429700100011 neutrons per fission from the observed number of 1429700100012 pulses per gate, it is necessary to know the 1429700100013 efficiency of the detector for fission neutrons. The 1429700100014 efficiency is determined in two ways. The first is to 1429700100015 assume the accurately known value of nubar for 235U 1429700100016 at thermal energy. The detector efficiency is the 1429700100017 mean number of neutrons detected per gate divided by 1429700100018 the known value of nubar. Another method is to 1429700100019 replace the fission detector with proton recoil 1429700100020 neutron detector such as hydrogen-filled proportional 1429700100021 counter that is inserted into the center of liquid 1429700100022 scintillator in place of the fission counter. Then 1429700100023 monoenergetic neutrons are passed through the 1429700100024 proportional counter, and the gate opened with pulses 1429700100025 produced by recoil protons. Every proportional 1429700100026 counter pulse is associated with the scattering of a 1429700100027 neutron out of the beam and into a liquid 1429700100028 scintillator by a hydrogen nucleus in the counter. 1429700100029 For fission spectrum, about 98.5% of the neutrons are 1429700100030 captured in the detector. 1429700100031 ERR-ANALYS (DATA-ERR) The standard deviations reflect 1429700100032 statistical uncertainty due to the number of fission 1429700100033 events observed and to 1429700100034 (ERR-1) the uncertainty in the nubar of 235U. 1429700100035 HISTORY (20170807C) BP 1429700100036 (20230710A) BP: Updated subentry 8. 1429700100037 (20240314U) On. Minor alteration in 008. 1429700100038 ENDBIB 36 0 1429700100039 COMMON 1 3 1429700100040 ERR-1 1429700100041 PER-CENT 1429700100042 1.2 1429700100043 ENDCOMMON 3 0 1429700100044 ENDSUBENT 43 0 1429700199999 SUBENT 14297002 20170807 14301429700200001 BIB 3 7 1429700200002 REACTION 1(98-CF-252(0,F),PR,NU) 1429700200003 2(98-CF-252(0,F),,NU) 1429700200004 ANALYSIS Determination of absolute nubar for spontaneous 1429700200005 fission of 252Cf. 1429700200006 STATUS (TABLE) Table I, page 153. 1429700200007 (COREL,14297003) Data normalized to 1429700200008 235U(nth,f) nu-bar=2.430. 1429700200009 ENDBIB 7 0 1429700200010 NOCOMMON 0 0 1429700200011 DATA 3 1 1429700200012 DATA 1DATA 2DATA-ERR 2 1429700200013 PRT/FIS PRT/FIS PER-CENT 1429700200014 3.722 3.731 3.0 1429700200015 ENDDATA 3 0 1429700200016 ENDSUBENT 15 0 1429700299999 SUBENT 14297003 20170807 14301429700300001 BIB 5 10 1429700300002 REACTION 1(98-CF-252(0,F),PR,NU) 1429700300003 2(98-CF-252(0,F),DL,NU) 1429700300004 3(98-CF-252(0,F),,NU) 1429700300005 ANALYSIS Determination of absolute nubar for spontaneous 1429700300006 fission of 252Cf normalized to "U.S. value" for nubar 1429700300007 of 235U. 1429700300008 MONITOR (92-U-235(N,F),,NU) 1429700300009 MONIT-REF ((MONIT),D.J.Hughes+,P,BNL-325,1960) 1429700300010 STATUS (TABLE) Table I, page 153. 1429700300011 (COREL,14297002) Absolute measurement 1429700300012 ENDBIB 10 0 1429700300013 COMMON 3 3 1429700300014 EN-NRM MONIT MONIT-ERR 1429700300015 EV PRT/FIS PER-CENT 1429700300016 0.023 2.430 1.2 1429700300017 ENDCOMMON 3 0 1429700300018 DATA 5 1 1429700300019 DATA 1DATA-ERR 1DATA 2DATA 3DATA-ERR 3 1429700300020 PRT/FIS PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700300021 3.739 0.051 0.009 3.748 0.051 1429700300022 ENDDATA 3 0 1429700300023 ENDSUBENT 22 0 1429700399999 SUBENT 14297004 20170807 14301429700400001 BIB 4 8 1429700400002 REACTION 1(92-U-233(N,F),PR,NU) 1429700400003 2(92-U-233(N,F),DL,NU) 1429700400004 3(92-U-233(N,F),,NU) 1429700400005 COMMENT The measurement of nubar for neutron-induced fission 1429700400006 of 233U, 235U and 239Pu relative to the nubar for the 1429700400007 spontaneous fission of 252Cf. 1429700400008 MONITOR (98-CF-252(0,F),,NU) 1429700400009 STATUS (TABLE) Table I, page 153. 1429700400010 ENDBIB 8 0 1429700400011 COMMON 2 3 1429700400012 EN MONIT 1429700400013 EV PRT/FIS 1429700400014 0.0253 3.73 1429700400015 ENDCOMMON 3 0 1429700400016 DATA 5 1 1429700400017 DATA 1DATA-ERR 1DATA 2DATA 3DATA-ERR 3 1429700400018 PRT/FIS PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700400019 2.440 0.041 0.007 2.447 0.041 1429700400020 ENDDATA 3 0 1429700400021 ENDSUBENT 20 0 1429700499999 SUBENT 14297005 20170807 14301429700500001 BIB 5 9 1429700500002 REACTION 1(92-U-233(N,F),PR,NU) 1429700500003 2(92-U-233(N,F),,NU) 1429700500004 INC-SOURCE (D-D) For neutron energies between 3.5-5 Mev the 1429700500005 D(d,n) reaction is used. 1429700500006 COMMENT The measurement of nubar for neutron-induced fission 1429700500007 of 233U, 235U and 239Pu relative to the nubar for the 1429700500008 spontaneous fission of 252Cf. 1429700500009 MONITOR (98-CF-252(0,F),,NU) 1429700500010 STATUS (TABLE) Table I, page 153. 1429700500011 ENDBIB 9 0 1429700500012 COMMON 2 3 1429700500013 EN MONIT 1429700500014 MEV PRT/FIS 1429700500015 4.0 3.73 1429700500016 ENDCOMMON 3 0 1429700500017 DATA 4 1 1429700500018 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 1429700500019 PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700500020 2.943 0.040 2.950 0.063 1429700500021 ENDDATA 3 0 1429700500022 ENDSUBENT 21 0 1429700599999 SUBENT 14297006 20170807 14301429700600001 BIB 4 7 1429700600002 REACTION 1(92-U-235(N,F),PR,NU) 1429700600003 2(92-U-235(N,F),DL,NU) 1429700600004 COMMENT The measurement of nubar for neutron-induced fission 1429700600005 of 233U, 235U and 239Pu relative to the nubar for the 1429700600006 spontaneous fission of 252Cf. 1429700600007 MONITOR (98-CF-252(0,F),,NU) 1429700600008 STATUS (TABLE) Table I, page 153. 1429700600009 ENDBIB 7 0 1429700600010 COMMON 2 3 1429700600011 EN MONIT 1429700600012 EV PRT/FIS 1429700600013 0.0253 3.73 1429700600014 ENDCOMMON 3 0 1429700600015 DATA 3 1 1429700600016 DATA 1DATA-ERR 1DATA 2 1429700600017 PRT/FIS PRT/FIS PRT/FIS 1429700600018 2.414 0.030 0.016 1429700600019 ENDDATA 3 0 1429700600020 ENDSUBENT 19 0 1429700699999 SUBENT 14297007 20170807 14301429700700001 BIB 5 9 1429700700002 REACTION 1(92-U-235(N,F),PR,NU) 1429700700003 2(92-U-235(N,F),,NU) 1429700700004 INC-SOURCE (D-D) For neutron energies between 3.5-5 Mev the 1429700700005 D(d,n) reaction is used. 1429700700006 COMMENT The measurement of nubar for neutron-induced fission 1429700700007 of 233U, 235U and 239Pu relative to the nubar for the 1429700700008 spontaneous fission of 252Cf. 1429700700009 MONITOR (98-CF-252(0,F),,NU) 1429700700010 STATUS (TABLE) Table I, page 153. 1429700700011 ENDBIB 9 0 1429700700012 COMMON 2 3 1429700700013 EN MONIT 1429700700014 MEV PRT/FIS 1429700700015 4.0 3.73 1429700700016 ENDCOMMON 3 0 1429700700017 DATA 4 1 1429700700018 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 1429700700019 PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700700020 2.903 0.048 2.919 0.048 1429700700021 ENDDATA 3 0 1429700700022 ENDSUBENT 21 0 1429700799999 SUBENT 14297008 20230710 20240316 1429700800001 BIB 5 17 1429700800002 REACTION 1(94-PU-240(0,F),PR,NU) 1429700800003 2(94-PU-240(0,F),DL,NU) 1429700800004 3(94-PU-240(0,F),,NU) 1429700800005 MONITOR (98-CF-252(0,F),,NU) 1429700800006 COMMENT The measurement of nubar for neutron-induced fission 1429700800007 of 233U, 235U and 239Pu relative to the nubar for the 1429700800008 spontaneous fission of 252Cf. Between -6.28 MeV and 1429700800009 thermal energy, zero threshold reaction. This 1429700800010 interpretation was questioned by the CF-252 1429700800011 evaluators (Denise Neudecker). Additional comment 1429700800012 from Naohiko: "...the authors provide the Pu240 with 1429700800013 En=-6.28 MeV rather than En='Spont.' in Table I. 1429700800014 (What is -6.28 MeV? Neutron separation energy of 1429700800015 240Pu, which is currently known to be ~6.53 MeV.) ." 1429700800016 HISTORY (20230710A) BP: Correctted data set from (N,F) to 1429700800017 spontaneous fission per CF-252 evaluation project. 1429700800018 STATUS (TABLE) Table I, page 153. 1429700800019 ENDBIB 17 0 1429700800020 COMMON 1 3 1429700800021 MONIT 1429700800022 PRT/FIS 1429700800023 3.73 1429700800024 ENDCOMMON 3 0 1429700800025 DATA 5 1 1429700800026 DATA 1DATA-ERR 1DATA 2DATA 3DATA-ERR 3 1429700800027 PRT/FIS PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700800028 2.167 0.036 0.009 2.176 0.036 1429700800029 ENDDATA 3 0 1429700800030 ENDSUBENT 29 0 1429700899999 SUBENT 14297009 20170807 14301429700900001 BIB 4 8 1429700900002 REACTION 1(94-PU-239(N,F),PR,NU) 1429700900003 2(94-PU-239(N,F),DL,NU) 1429700900004 3(94-PU-239(N,F),,NU) 1429700900005 COMMENT The measurement of nubar for neutron-induced fission 1429700900006 of 233U, 235U and 239Pu relative to the nubar for the 1429700900007 spontaneous fission of 252Cf. 1429700900008 MONITOR (98-CF-252(0,F),,NU) 1429700900009 STATUS (TABLE) Table I, page 153. 1429700900010 ENDBIB 8 0 1429700900011 COMMON 2 3 1429700900012 EN MONIT 1429700900013 EV PRT/FIS 1429700900014 0.0253 3.73 1429700900015 ENDCOMMON 3 0 1429700900016 DATA 5 1 1429700900017 DATA 1DATA-ERR 1DATA 2DATA 3DATA-ERR 3 1429700900018 PRT/FIS PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429700900019 2.814 0.046 0.006 2.820 0.046 1429700900020 ENDDATA 3 0 1429700900021 ENDSUBENT 20 0 1429700999999 SUBENT 14297010 20170807 14301429701000001 BIB 5 9 1429701000002 REACTION 1(94-PU-239(N,F),PR,NU) 1429701000003 2(94-PU-239(N,F),,NU) 1429701000004 INC-SOURCE (D-D) For neutron energies between 3.5-5 Mev the 1429701000005 D(d,n) reaction is used. 1429701000006 COMMENT The measurement of nubar for neutron-induced fission 1429701000007 of 233U, 235U and 239Pu relative to the nubar for the 1429701000008 spontaneous fission of 252Cf. 1429701000009 MONITOR (98-CF-252(0,F),,NU) 1429701000010 STATUS (TABLE) Table I, page 153. 1429701000011 ENDBIB 9 0 1429701000012 COMMON 2 3 1429701000013 EN MONIT 1429701000014 MEV PRT/FIS 1429701000015 4.0 3.73 1429701000016 ENDCOMMON 3 0 1429701000017 DATA 4 1 1429701000018 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 1429701000019 PRT/FIS PRT/FIS PRT/FIS PRT/FIS 1429701000020 3.415 0.063 3.421 0.063 1429701000021 ENDDATA 3 0 1429701000022 ENDSUBENT 21 0 1429701099999 ENDENTRY 10 0 1429799999999