ENTRY 40757 20231113 421640757 0 1 SUBENT 40757001 20231113 421640757 1 1 BIB 8 51 40757 1 2 TITLE Measurements of the average number of neutrons emitted 40757 1 3 in the fission of some uranium and plutonium isotopes. 40757 1 4 COMMENT This article contains three parts: 40757 1 5 Part I. Page 123. 40757 1 6 Relative measurements of the average number of 40757 1 7 neutrons emitted in the thermal fission of U233, U235, 40757 1 8 Pu239, and Pu241. 40757 1 9 V.I.Kalashnikova,V.I.Lebedev,L.A.Mikaelyan, 40757 1 10 P.E.Spivak,V.P.Zakharova 40757 1 11 Part II. Page 127. 40757 1 12 Dependence of the number of neutrons emitted 40757 1 13 in the fission of heavy nuclei on the excitation 40757 1 14 energy of the fissionable nucleus. 40757 1 15 V.I.Kalashnikova, A.V.Krasnushkin, V.I.Lebedev, 40757 1 16 M.I.Pevzner, V.P.Zakharova 40757 1 17 Part III. Page 131. 40757 1 18 Absolute evaluation of the average number of 40757 1 19 neutrons emitted in the fission of some isotopes of 40757 1 20 uranium and plutonium. 40757 1 21 V.I.Kalashnikova,V.I.Lebedev,P.E.Spivak,V.P.Zakharova. 40757 1 22 In "V.I.Kalashnikov" (in part III) there is a misprint,40757 1 23 right "V.I.Kalashnikova", see Parts I, II on pages 40757 1 24 123, 127 of AEC-TR-2435,vol.1. 40757 1 25 .Of compiler M.M. 40757 1 26 This article was presented at 55MOSCOW ( candidates to40757 1 27 55GENEVA were discussed), 40757 1 28 and as mentioned in R,UCRL-50400,v.2,rev.2,1976, 40757 1 29 at 55GENEVA it was reported by M.S.Kozodaev at 40757 1 30 discussion of P/592 - see 55GENEVA,vol.2, 40757 1 31 p.228(English), p.258(Russian edition). 40757 1 32 In "V.I.Kalashnikov" there is probably a misprint, 40757 1 33 right "V.I.Kalashnikova", see Parts I, II on pages 40757 1 34 123, 127 of AEC-TR-2435,vol.1. 40757 1 35 AUTHOR (V.I.Kalashnikova,V.I.Lebedev,L.A.Mikaelyan, 40757 1 36 P.E.Spivak,V.P.Zakharova, A.V.Krasnukhin, M.I.Pevzner) 40757 1 37 REFERENCE (S,AEC-TR-2435,(1),131,1956) Part III. 40757 1 38 (S,AEC-TR-2435,(1),127,1956) Part II. 40757 1 39 (C,55MOSCOW,1,156,1955) 40757 1 40 REL-REF (N,,M.S.Kozodaev,C,55GENEVA,2,258,1955) 40757 1 41 Comments of M.S.Kozodaev at discussion of P/502. 40757 1 42 Data were confirmed (Subents 002-004). 40757 1 43 INSTITUTE (4RUSKUR) 40757 1 44 DETECTOR (PROPC) Neutrons detected by 24 BF3 counters in 40757 1 45 paraffin. 40757 1 46 (IOCH) 40757 1 47 HISTORY (19840522T) Converted from ENTRY 80157 40757 1 48 (20231113A) Upper -> lower case correction. 40757 1 49 Dates were corrected for 4-digits year. 40757 1 50 DEP code was added in STATUS of data Subents. 40757 1 51 Units were corrected: NO-DIM -> PRT/FIS 40757 1 52 Subents 005-007 were added. 40757 1 53 ENDBIB 51 0 40757 1 54 NOCOMMON 0 0 40757 1 55 ENDSUBENT 54 0 40757 199999 SUBENT 40757002 20231113 421640757 2 1 BIB 7 25 40757 2 2 REACTION (94-PU-239(N,F),PR,NU,,MXW) 40757 2 3 INC-SOURCE .Calibrated neutron source 40757 2 4 .Thermal neutron beam 40757 2 5 INC-SPECT .Fission neutron spectrum 40757 2 6 .Thermal spectrum 40757 2 7 MONITOR (92-U-235(N,F),PR,NU,,MXW) 40757 2 8 COMMENT .Of N.Otsuka (NDS,IAEA). 40757 2 9 It's not clear, why the authors used U-235 fission NU 40757 2 10 as monitor (given in DATA block) but not U-233 fission 40757 2 11 NU measured by the authors (given in Subent 007). 40757 2 12 ERR-ANALYS (DATA-ERR) Error mainly resulting from neutron source 40757 2 13 strength inaccuracy (+-3.%). 40757 2 14 STATUS (TABLE,,V.I.Kalashnikov+,S,AEC-TR-2435,(1),131,1956) 40757 2 15 Table 6 on page 131 40757 2 16 See also text of M.S.Kozodaev,C,55GENEVA,2,258,1955 - 40757 2 17 data were confirmed. 40757 2 18 (DEP,40756002) Ratio Pu-239/U-235 at thermal energy. 40757 2 19 (OUTDT) It's not clear, 40757 2 20 - what was monitor: 40757 2 21 1)U-235 NU as mentioned in AEC-TR-2435,(1),131,1956 or 40757 2 22 2) U-233 NU as in M.S.Kozodaev,C,55GENEVA,2,258,1955 40757 2 23 - what was incident neutron energy: 40757 2 24 1) thermal (used in DATA block as EN-DUMMY because 40757 2 25 U233/U235 was measured at thermal energy) or 40757 2 26 2) fission spectrum energy. 40757 2 27 ENDBIB 25 0 40757 2 28 NOCOMMON 0 0 40757 2 29 DATA 4 1 40757 2 30 EN-DUMMY DATA DATA-ERR MONIT 40757 2 31 MEV PRT/FIS PER-CENT PRT/FIS 40757 2 32 2.5300E-08 3.0 4. 2.5 40757 2 33 ENDDATA 3 0 40757 2 34 ENDSUBENT 33 0 40757 299999 SUBENT 40757003 20231113 421640757 3 1 BIB 7 26 40757 3 2 REACTION (94-PU-241(N,F),PR,NU,,MXW) 40757 3 3 INC-SOURCE .Calibrated neutron source 40757 3 4 .Thermal neutron beam 40757 3 5 INC-SPECT .Fission neutron spectrum 40757 3 6 .Thermal spectrum 40757 3 7 MONITOR (92-U-235(N,F),PR,NU,,MXW) 40757 3 8 COMMENT .Of N.Otsuka (NDS,IAEA). 40757 3 9 It's not clear, why the authors used U-235 fission NU 40757 3 10 as monitor (given in DATA block) but not U-233 fission 40757 3 11 NU measured by the authors (given in Subent 007). 40757 3 12 ERR-ANALYS (DATA-ERR) Error mainly resulting from neutron source 40757 3 13 strength inaccuracy (+-3.%). 40757 3 14 STATUS (TABLE,,V.I.Kalashnikov+,S,AEC-TR-2435,(1),131,1956) 40757 3 15 Table 6 on page 131 40757 3 16 See also text of M.S.Kozodaev,C,55GENEVA,2,258,1955 - 40757 3 17 data were confirmed. 40757 3 18 (DEP,40756003) Ratio Pu241/Pu239 at thermal energy 40757 3 19 (DEP,40756002) Ratio Pu239/U235 at thermal energy 40757 3 20 (OUTDT) It's not clear, 40757 3 21 - what was monitor: 40757 3 22 1)U-235 NU as mentioned in AEC-TR-2435,(1),131,1956 or 40757 3 23 2)U-233 NU as in M.S.Kozodaev,C,55GENEVA,2,258,1955 40757 3 24 - what was incident neutron energy: 40757 3 25 1) thermal (used in DATA block as EN-DUMMY because 40757 3 26 U233/U235 was measured at thermal energy) or 40757 3 27 2) fission spectrum energy. 40757 3 28 ENDBIB 26 0 40757 3 29 NOCOMMON 0 0 40757 3 30 DATA 4 1 40757 3 31 EN-DUMMY DATA DATA-ERR MONIT 40757 3 32 MEV PRT/FIS PER-CENT PRT/FIS 40757 3 33 2.5300E-08 3.1 4. 2.5 40757 3 34 ENDDATA 3 0 40757 3 35 ENDSUBENT 34 0 40757 399999 SUBENT 40757004 20231113 421640757 4 1 BIB 7 27 40757 4 2 REACTION (92-U-233(N,F),PR,NU,,MXW) 40757 4 3 INC-SOURCE .Thermal neutron beam 40757 4 4 INC-SPECT .Thermal spectrum 40757 4 5 MONITOR (92-U-235(N,F),PR,NU,,MXW) 40757 4 6 COMMENT .Of N.Otsuka (NDS,IAEA). 40757 4 7 It's not clear, why the authors used U-235 fission NU 40757 4 8 as monitor (given in DATA block) but not U-233 fission 40757 4 9 NU measured by the authors (given in Subent 007). 40757 4 10 ERR-ANALYS (DATA-ERR) Error mainly resulting from neutron source 40757 4 11 strength inaccuracy (+-3.%). 40757 4 12 STATUS (TABLE,,V.I.Kalashnikov+,S,AEC-TR-2435,(1),131,1956) 40757 4 13 Text on page 131 (with uncertainty), 40757 4 14 Table 6 (without uncertainty) 40757 4 15 See also text of M.S.Kozodaev,C,55GENEVA,2,258,1955 - 40757 4 16 data were confirmed. 40757 4 17 (DEP,40756004) Ratio U-233/U-235 at thermal energy 40757 4 18 (COREL,40757007) U-233 Nu determined by calibrated 40757 4 19 source. 40757 4 20 (OUTDT) It's not clear, 40757 4 21 - what was monitor: 40757 4 22 1)U-235 NU as mentioned in AEC-TR-2435,(1),131,1956 or 40757 4 23 2)U-233 NU in M.S.Kozodaev,C,55GENEVA,2,258,1955 is 40757 4 24 mentioned once as determined by calibrated source; 40757 4 25 - what was incident neutron energy: 40757 4 26 1) thermal (used in DATA block as EN-DUMMY because 40757 4 27 U233/U235 was measured at thermal energy) or 40757 4 28 2) fission spectrum energy. 40757 4 29 ENDBIB 27 0 40757 4 30 NOCOMMON 0 0 40757 4 31 DATA 4 1 40757 4 32 EN-DUMMY DATA DATA-ERR MONIT 40757 4 33 MEV PRT/FIS PER-CENT PRT/FIS 40757 4 34 2.5300E-08 2.6 4. 2.5 40757 4 35 ENDDATA 3 0 40757 4 36 ENDSUBENT 35 0 40757 499999 SUBENT 40757005 20231113 421640757 5 1 BIB 7 21 40757 5 2 REACTION (94-PU-239(N,F),PR,NU,,MXW)/(94-PU-240(0,F),PR,NU) 40757 5 3 INC-SOURCE .Thermal neutron beam 40757 5 4 INC-SPECT .Thermal spectrum 40757 5 5 SAMPLE Thin layer (0.2 mg/cm2) of mixture of Pu-240 and 40757 5 6 Pu-239 in approximately equal proportions. 40757 5 7 Total weight of Pu 1.7 mg. 40757 5 8 METHOD (COINC) Fission fragmants and neutrons coincidence. 40757 5 9 Two series of measurement: 40757 5 10 Ser. Isotope Nfragments Ncoincidences NU*w*eta 40757 5 11 I Pu239 33,826 4,375 0.128+-0.002 40757 5 12 Pu240 19,467 1,897 0.097+-0.002 40757 5 13 II Pu239 483,712 61,432 0.1270+-0.000740757 5 14 Pu240 21,232 2,003 0.094+-0.002 40757 5 15 Where 40757 5 16 w - solid angle, 40757 5 17 eta - detection efficiency. 40757 5 18 ERR-ANALYS (ERR-S) Statistical error. 40757 5 19 Systematic error is sufficiently small - comment of 40757 5 20 authors in the article. 40757 5 21 STATUS (TABLE,,V.I.Kalashnikova+,S,AEC-TR-2435,(1),127,1956) 40757 5 22 Text on page 129 40757 5 23 ENDBIB 21 0 40757 5 24 NOCOMMON 0 0 40757 5 25 DATA 3 1 40757 5 26 EN-DUMMY DATA ERR-S 40757 5 27 EV NO-DIM NO-DIM 40757 5 28 0.0253 1.33 0.03 40757 5 29 ENDDATA 3 0 40757 5 30 ENDSUBENT 29 0 40757 599999 SUBENT 40757006 20231113 421640757 6 1 BIB 3 7 40757 6 2 REACTION (94-PU-240(0,F),PR,NU) 40757 6 3 ERR-ANALYS (DATA-ERR) Error mainly resulting from neutron source 40757 6 4 strength inaccuracy (+-3.%). 40757 6 5 STATUS (TABLE,,V.I.Kalashnikov+,S,AEC-TR-2435,(1),131,1956) 40757 6 6 Table 6. 40757 6 7 (DEP,40756005) Ratio Pu239(n,f)/Pu240(spont.fis.) 40757 6 8 (DEP,40757002) Pu239 40757 6 9 ENDBIB 7 0 40757 6 10 NOCOMMON 0 0 40757 6 11 DATA 3 1 40757 6 12 DATA DATA-ERR MONIT 40757 6 13 PRT/FIS PER-CENT PRT/FIS 40757 6 14 2.2 4. 2.5 40757 6 15 ENDDATA 3 0 40757 6 16 ENDSUBENT 15 0 40757 699999 SUBENT 40757007 20231113 421640757 7 1 BIB 8 27 40757 7 2 REACTION (92-U-233(N,F),PR,NU,,FIS) 40757 7 3 INC-SPECT .Calibrated source spectrum was very similar to the 40757 7 4 fission spectrum. 40757 7 5 METHOD . The quantity w*eta was measured with the calibrated 40757 7 6 source and was found to be (5.35+-0.15) %. 40757 7 7 .Dependence of quantity NU*w*eta on resolving time t : 40757 7 8 t,sec NU*w*eta 40757 7 9 1.6E-04 0.0117 40757 7 10 2.8E-04 0.134 40757 7 11 3.4E-04 0.136 40757 7 12 4.3E-04 0.140 40757 7 13 5.0E-04 0.140 40757 7 14 w - solid angle, 40757 7 15 eta - neutron detection efficiency. 40757 7 16 ANALYSIS NU was determined from measured (with calibrated 40757 7 17 source) w*eta and measured NU*w*eta = 0.140+-0.001. 40757 7 18 COMMENT .Of compiler M.M. 40757 7 19 From the text of the Part III article it is not enouth40757 7 20 clear, what incident spectrum was at measuremet of 40757 7 21 NU*w*eta - calibrated source spectrum or 40757 7 22 thermal spectrum. 40757 7 23 ERR-ANALYS (DATA-ERR) Type of uncertainty is not explained in the 40757 7 24 article. 40757 7 25 STATUS (TABLE,,V.I.Kalashnikov+,S,AEC-TR-2435,(1),131,1956) 40757 7 26 Text on page 131. 40757 7 27 HISTORY (20231113C) Subent was added according to a comment of 40757 7 28 N.Otsuka (NDS,IAEA). 40757 7 29 ENDBIB 27 0 40757 7 30 NOCOMMON 0 0 40757 7 31 DATA 3 1 40757 7 32 EN-DUMMY DATA DATA-ERR 40757 7 33 MEV PRT/FIS PRT/FIS 40757 7 34 1. 2.6 0.1 40757 7 35 ENDDATA 3 0 40757 7 36 ENDSUBENT 35 0 40757 799999 ENDENTRY 7 0 4075799999999