ENTRY 20025 20170125 22572002500000001 SUBENT 20025001 20170125 22572002500100001 BIB 13 43 2002500100002 INSTITUTE (2SWDFOA) 2002500100003 REFERENCE (J,AF,29,293,196503) Main reference. 2002500100004 (C,65SALZBURG,2,57,1965) Prelim. thermal value given. 2002500100005 AUTHOR (H.Conde) 2002500100006 TITLE Average number of neutrons from the fission of U-235 2002500100007 FACILITY (VDG,2SWDFOA) 2.5 MeV Van de Graaff for 60 keV neutrons2002500100008 (VDG,2SWDAE ) 5 MeV Van de Graaff for 7.5 MeV neutrons.2002500100009 (CCW,2SWDFOA) Electrostatic accelerator for 14.8 MeV 2002500100010 neutrons. 2002500100011 INC-SOURCE (P-LI7) Li-7(p,n)-reaction for 60 keV neutrons 2002500100012 (D-D) D(d,n)-reaction for 7.5 MeV neutrons 2002500100013 (D-T) T(d,n)-reaction for 14.8 MeV neutrons 2002500100014 SAMPLE 56 mg of U-235 was deposited on five platinum disks 2002500100015 with a coating thickness of 1.5 mg/cm2. 2002500100016 The material was enriched to 93% U-235, 6% U-238 2002500100017 and 1% U-234. 2002500100018 METHOD (COINC) Coincidence 2002500100019 (TOF) Time of flight technique at 7.5 and 14.8 MeV 2002500100020 DETECTOR (SCIN) Large spherical liquid scintillator for the 2002500100021 liquid 60 keV and 14.8 MeV data and a large cylindrical2002500100022 scintillator for the 7.5 MeV data. 2002500100023 COMMENT Data are compared with other measurements a mean value2002500100024 for nu-bar(thermal)(U-235)=2.412+-0.015 is derived 2002500100025 CORRECTION .Pile-up (0.1 - 0.4%), 2002500100026 .false gates (0.1%), 2002500100027 .differences in fission neutron spectra (0.3 - 0.6%), 2002500100028 .anisotropy of fission neutron emission (0.1%), 2002500100029 .fission foil thickness (0.3%), 2002500100030 .fission by background neutrons (0.1 - 0.2%), 2002500100031 .impurities in fissile deposit (0.1%), 2002500100032 .uncertainty in the primary neutron energy (0.1 - 0.4%)2002500100033 The total correction was estimated to be -0.013+-0.007 2002500100034 ERR-ANALYS (DATA-ERR) The stated error includes counting 2002500100035 statistics and uncertainties in the corrections. 2002500100036 (MONIT-ERR) Uncertainty in Cf standard 2002500100037 HISTORY (19710517T) From NEUDADA file 2002500100038 (19800825A) changed to reaction formalism. 2002500100039 (20160907A) SD:Updated to new date formats,lower case. 2002500100040 REACTION code update in Subent 003 according to comment2002500100041 from N.Otsuka. Data units were changed following EXFOR 2002500100042 rules. 2002500100043 (20170125A) SD: Subent 004 was added from 20112 Entry. 2002500100044 MONITOR (-ERR) moved to Subents 002-003. 2002500100045 ENDBIB 43 0 2002500100046 NOCOMMON 0 0 2002500100047 ENDSUBENT 46 0 2002500199999 SUBENT 20025002 20170125 22572002500200001 BIB 5 5 2002500200002 REACTION (92-U-235(N,F),PR,NU) 2002500200003 COMMENT Nu-bar at 60 keV is not given. 2002500200004 MONITOR (98-CF-252(0,F),PR,NU) 2002500200005 STATUS (TABLE) Data from the abstract of AF,29,293,1965 2002500200006 HISTORY (20170125A) SD: MONIT (-ERR) were added from Subent 0012002500200007 ENDBIB 5 0 2002500200008 COMMON 2 3 2002500200009 MONIT MONIT-ERR 2002500200010 PRT/FIS PRT/FIS 2002500200011 3.767 0.020 2002500200012 ENDCOMMON 3 0 2002500200013 DATA 3 2 2002500200014 EN DATA DATA-ERR 2002500200015 MEV PRT/FIS PRT/FIS 2002500200016 7.5 3.49 0.06 2002500200017 14.8 4.47 0.09 2002500200018 ENDDATA 4 0 2002500200019 ENDSUBENT 18 0 2002500299999 SUBENT 20025003 20170125 22572002500300001 BIB 5 12 2002500300002 REACTION 1(92-U-235(N,F),PR,NU,,,DERIV) 2002500300003 2((92-U-235(N,F),PR,NU,,,DERIV)/ 2002500300004 (98-CF-252(0,F),PR,NU)) 2002500300005 MONITOR 1(98-CF-252(0,F),PR,NU) 2002500300006 ANALYSIS The thermal nu-bar value is calculated by 2002500300007 an extrapolation to thermal energy assuming a linear 2002500300008 energy dependence of nu-bar with a slope of 0.085 2002500300009 neutrons per MeV. 2002500300010 STATUS (TABLE) Table 3 of Ark.Fys.29(1965)293 2002500300011 HISTORY (20160907A) SD: SF9=DERIV added to REACTION code. 2002500300012 Second REACTION code and data were added. 2002500300013 (20170125A) SD: MONIT (-ERR) were added from Subent 0012002500300014 ENDBIB 12 0 2002500300015 COMMON 2 3 2002500300016 MONIT 1MONIT-ERR 1 2002500300017 PRT/FIS PRT/FIS 2002500300018 3.767 0.020 2002500300019 ENDCOMMON 3 0 2002500300020 DATA 5 1 2002500300021 EN DATA 1DATA-ERR 1DATA 2DATA-ERR 2 2002500300022 MEV PRT/FIS PRT/FIS NO-DIM NO-DIM 2002500300023 2.5300E-08 2.411 0.023 0.6400 0.0053 2002500300024 ENDDATA 3 0 2002500300025 ENDSUBENT 24 0 2002500399999 SUBENT 20025004 20170122 22572002500400001 BIB 9 23 2002500400002 REACTION (92-U-235(N,F),PR,NU,,,DERIV) 2002500400003 MONITOR (98-CF-252(0,F),PR,NU) 2002500400004 ANALYSIS .The thermal nu-bar-value was calculated by 2002500400005 an extrapolation to thermal energy assuming a linear 2002500400006 energy dependence of nu-bar with a slope of 2002500400007 0.085 neutrons/MeV, starting from nu-bar at 60 keV. 2002500400008 REL-REF (A,12326004,J.C.Hopkins+,J,NP,48,433,1963) and 2002500400009 A.Moat,D.S.Mather,P.Fieldhouse priv.communication 2002500400010 COMMENT .Nu-bar(total) = 2.433+-0.015 at thermal energy is 2002500400011 obtained by adding nu-bar(delayed) from S.Cox et al., 2002500400012 Phys.Rev., 112(1958)960. 2002500400013 .Estimated nu-bar for 7.5 MeV is 3.47 +- 0.06. 2002500400014 .the 60 keV value is not given. 2002500400015 CORRECTION .The total correction was estimated to be 0.013+-0.007.2002500400016 ERR-ANALYS .The error given for the relative value includes 2002500400017 counting statistics and uncertainties in the 2002500400018 corrections 2002500400019 STATUS (TABLE) Data are from 65SALZBURG,2,57,1965 2002500400020 (SPSDD,20025003) The values of 20025.003 Subent 2002500400021 supersedes this Subent. 2002500400022 HISTORY (19710513T) From NEUDADA file 2002500400023 (20170122T) SD: Subent was originally from 20112.003. 2002500400024 BIB update. SF9=DERIV added to REACTION code. 2002500400025 ENDBIB 23 0 2002500400026 COMMON 2 3 2002500400027 MONIT MONIT-ERR 2002500400028 PRT/FIS PRT/FIS 2002500400029 3.775 0.002 2002500400030 ENDCOMMON 3 0 2002500400031 DATA 3 1 2002500400032 EN DATA DATA-ERR 2002500400033 MEV PRT/FIS PRT/FIS 2002500400034 2.53E-08 2.417 0.015 2002500400035 ENDDATA 3 0 2002500400036 ENDSUBENT 35 0 2002500499999 ENDENTRY 4 0 2002599999999