ENTRY 21456 20230220 231621456 0 1 SUBENT 21456001 20230220 231621456 1 1 BIB 13 35 21456 1 2 TITLE A comparison of the average number of neutrons emitted 21456 1 3 in fission of some uranium and plutonium isotopes 21456 1 4 AUTHOR (J.E.Sanders) 21456 1 5 REFERENCE (J,JNE,2,247,1956) final data 21456 1 6 (C,55GENEVA,4,307,1955) Egelstaff+, review article. 21456 1 7 (R,AERE-RP/R-1627,1955) Sanders+, superseded. 21456 1 8 (R,AERE-NP/R-2140,1957) Egelstaff+, evaluation. 21456 1 9 (R,AERE-NP/R-2104,1957) Egelstaff, compilation. 21456 1 10 (R,AERE-RP/R-1655,1955) nu(239Pu) 21456 1 11 INSTITUTE (2UK HAR) 21456 1 12 FACILITY (REAC,2UK HAR) BEPO-reactor. 21456 1 13 INC-SOURCE (THCOL) Thermal column. 21456 1 14 INC-SPECT Maxwellian neutron spectrum (thermal column). 21456 1 15 DETECTOR (COIN,FISCH,BF3) Coincidences between the fission 21456 1 16 fragments and the prompt neutrons. Fission chamber 21456 1 17 contained 15 cm Ar + 1 cm C-O(2). Ring of 16 BF3 21456 1 18 counters embedded in a block of paraffin wax 21456 1 19 surrounded the fission chamber. They had a pressure 21456 1 20 of 40 cm. Enriched boron-10 (96 perc), 13 cm long * 21456 1 21 2.3 cm diam. Sensitive volume. 21456 1 22 PART-DET (FF) Fission fragments in coincidence with 21456 1 23 (PN) prompt fission neutrons. 21456 1 24 CORRECTION Correction for the difference in the 21456 1 25 fission neutron spectra of the different isotopes, 21456 1 26 which causes a difference in detection efficiency. 21456 1 27 ERR-ANALYS (DATA-ERR) Error due to gate length within 21456 1 28 statistical error. Quoted error is standard deviation 21456 1 29 from the mean of a number of measurements (+ 1% from 21456 1 30 the correction on the efficiency for different 21456 1 31 fission neutron spectra in the case of the values 21456 1 32 derived from relative measurements.) 21456 1 33 STATUS (TABLE) Tbl.3 from J.Nucl.En.,2,247,1956 21456 1 34 HISTORY (19800310T) G.C. 21456 1 35 (20230220U) SD:Updated to new date formats,lower case. 21456 1 36 Corrections in all Subents. 21456 1 37 ENDBIB 35 0 21456 1 38 COMMON 1 3 21456 1 39 EN-DUMMY 21456 1 40 EV 21456 1 41 2.5300E-02 21456 1 42 ENDCOMMON 3 0 21456 1 43 ENDSUBENT 42 0 21456 199999 SUBENT 21456002 20230220 231621456 2 1 BIB 3 6 21456 2 2 REACTION ((92-U-233(N,F),PR,NU,,MXW)/ 21456 2 3 (92-U-235(N,F),PR,NU,,MXW)) 21456 2 4 SAMPLE Back-to-back foils of a few mg of oxide on 21456 2 5 Al or Pt backings of about 0.01 cm thickness. 21456 2 6 Isotopic enrichments 99.5% (U-233) and 81.2% (U-235). 21456 2 7 HISTORY (20230220U) SD: BIB updated. 21456 2 8 ENDBIB 6 0 21456 2 9 NOCOMMON 0 0 21456 2 10 DATA 2 1 21456 2 11 DATA DATA-ERR 21456 2 12 NO-DIM NO-DIM 21456 2 13 1.005 0.016 21456 2 14 ENDDATA 3 0 21456 2 15 ENDSUBENT 14 0 21456 299999 SUBENT 21456003 20230220 231621456 3 1 BIB 3 6 21456 3 2 REACTION ((94-PU-239(N,F),PR,NU,,MXW)/ 21456 3 3 (92-U-235(N,F),PR,NU,,MXW)) 21456 3 4 SAMPLE Back-to-back layers of a few mg of oxide on 21456 3 5 Al or Pt backings of about 0.01 cm thickness. 21456 3 6 Isotopic enrichment of 99.4%(Pu-239) and 81.2%(U-235).21456 3 7 HISTORY (20230220U) SD: BIB updated. 21456 3 8 ENDBIB 6 0 21456 3 9 NOCOMMON 0 0 21456 3 10 DATA 2 1 21456 3 11 DATA DATA-ERR 21456 3 12 NO-DIM NO-DIM 21456 3 13 1.168 0.022 21456 3 14 ENDDATA 3 0 21456 3 15 ENDSUBENT 14 0 21456 399999 SUBENT 21456004 20230220 231621456 4 1 BIB 4 12 21456 4 2 REACTION ((94-PU-241(N,F),PR,NU,,MXW)/ 21456 4 3 (92-U-235(N,F),PR,NU,,MXW)) 21456 4 4 SAMPLE Back-to-back foils of a few mg of oxide on 21456 4 5 Al or Pt backings of about 0.01 cm thickness. 21456 4 6 Isotopic enrichment of 81.2 perc for the U-235 foil. 21456 4 7 The Pu-foil was prepared using highly irradiated Pu 21456 4 8 from the nrx pile at chalk river. 21456 4 9 It contained 26.8% Pu-239, and 13.9% Pu-241. 21456 4 10 CORRECTION A 0.5% correction was made for the spontaneous 21456 4 11 fission of Pu-240 and Pu-242. (these have no thermal 21456 4 12 fission). 21456 4 13 HISTORY (20230220U) SD: BIB updated. 21456 4 14 ENDBIB 12 0 21456 4 15 NOCOMMON 0 0 21456 4 16 DATA 2 1 21456 4 17 DATA DATA-ERR 21456 4 18 NO-DIM NO-DIM 21456 4 19 1.232 0.052 21456 4 20 ENDDATA 3 0 21456 4 21 ENDSUBENT 20 0 21456 499999 SUBENT 21456005 20230220 231621456 5 1 BIB 4 11 21456 5 2 REACTION (92-U-235(N,F),PR,NU,,MXW) 21456 5 3 SAMPLE 2 Thin walled cylinders of natural uranium, length 21456 5 4 10 cm, outer diam 10 cm, 1.93 kg (3.2 mm wall 21456 5 5 thickness), and 0.925 kg (1.5 mm wall thickness). 21456 5 6 For the U-235 an oxide layer deposited on a Al or Pt 21456 5 7 backing of 0.01 mm thickness was used, with an 21456 5 8 isotopic enrichment of 81.2%. 21456 5 9 METHOD Detection efficiency calibrated by a natural U 21456 5 10 source with a spontaneous fission rate of 1.59+-0.09 21456 5 11 neutrons/gram*second. 21456 5 12 HISTORY (20230220U) SD: BIB updated. 21456 5 13 ENDBIB 11 0 21456 5 14 NOCOMMON 0 0 21456 5 15 DATA 2 1 21456 5 16 DATA DATA-ERR 21456 5 17 PRT/FIS PRT/FIS 21456 5 18 2.45 0.15 21456 5 19 ENDDATA 3 0 21456 5 20 ENDSUBENT 19 0 21456 599999 SUBENT 21456006 20230220 231621456 6 1 BIB 4 7 21456 6 2 REACTION (92-U-233(N,F),PR,NU,,MXW) 21456 6 3 SAMPLE Back-to-back foils of a few mg of oxide on 21456 6 4 Al or Pt backings of about 0.01 cm thickness. 21456 6 5 Isotopic enrichments of 81.2% (monitor-foil) 21456 6 6 and 99.5% (U-233 foil). 21456 6 7 STATUS (DEP,21456002) Ratio 233U/235U 21456 6 8 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 21456 6 9 ENDBIB 7 0 21456 6 10 NOCOMMON 0 0 21456 6 11 DATA 2 1 21456 6 12 DATA DATA-ERR 21456 6 13 PRT/FIS PRT/FIS 21456 6 14 2.46 0.15 21456 6 15 ENDDATA 3 0 21456 6 16 ENDSUBENT 15 0 21456 699999 SUBENT 21456007 20230220 231621456 7 1 BIB 4 7 21456 7 2 REACTION (94-PU-239(N,F),PR,NU,,MXW) 21456 7 3 SAMPLE Back-to-back foils of a few milligrams of oxide on 21456 7 4 Al or Pt backings of about 0.01 cm thickness. 21456 7 5 Isotopic enrichment 81.2% (monitor-foil) and 21456 7 6 99.4% (Pu-239 foil). 21456 7 7 STATUS (DEP,21456003) Ratio 239Pu/235U 21456 7 8 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 21456 7 9 ENDBIB 7 0 21456 7 10 NOCOMMON 0 0 21456 7 11 DATA 2 1 21456 7 12 DATA DATA-ERR 21456 7 13 PRT/FIS PRT/FIS 21456 7 14 2.86 0.18 21456 7 15 ENDDATA 3 0 21456 7 16 ENDSUBENT 15 0 21456 799999 SUBENT 21456008 20230220 231621456 8 1 BIB 5 12 21456 8 2 REACTION (94-PU-241(N,F),PR,NU,,MXW) 21456 8 3 SAMPLE Back-to-back foils of a few mg of oxide on 21456 8 4 Al or Pt backings of about 0.01 cm thickness. 21456 8 5 Isotopic enrichment of the monitor foil 81.2%. 21456 8 6 The Pu-foil was prepared using highly irradiated Pu 21456 8 7 from the NRX-pile at Chalk River, and contained 26.8% 21456 8 8 Pu-239, and 13.9% Pu-241. 21456 8 9 CORRECTION A 0.5% correction was made for the spontaneous 21456 8 10 fission from Pu-240 and Pu-242 in the sample. (These 21456 8 11 isotopes have no thermal fission). 21456 8 12 STATUS (DEP,21456004) Ratio 241Pu/235U 21456 8 13 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 21456 8 14 ENDBIB 12 0 21456 8 15 NOCOMMON 0 0 21456 8 16 DATA 2 1 21456 8 17 DATA DATA-ERR 21456 8 18 PRT/FIS PRT/FIS 21456 8 19 3.02 0.21 21456 8 20 ENDDATA 3 0 21456 8 21 ENDSUBENT 20 0 21456 899999 ENDENTRY 8 0 2145699999999