ENTRY 21456 20230220 2145600000001 SUBENT 21456001 20230220 20231011 2145600100001 BIB 13 35 2145600100002 TITLE A comparison of the average number of neutrons emitted 2145600100003 in fission of some uranium and plutonium isotopes 2145600100004 AUTHOR (J.E.Sanders) 2145600100005 REFERENCE (J,JNE,2,247,1956) final data 2145600100006 (C,55GENEVA,4,307,1955) Egelstaff+, review article. 2145600100007 (R,AERE-RP/R-1627,1955) Sanders+, superseded. 2145600100008 (R,AERE-NP/R-2140,1957) Egelstaff+, evaluation. 2145600100009 (R,AERE-NP/R-2104,1957) Egelstaff, compilation. 2145600100010 (R,AERE-RP/R-1655,1955) nu(239Pu) 2145600100011 INSTITUTE (2UK HAR) 2145600100012 FACILITY (REAC,2UK HAR) BEPO-reactor. 2145600100013 INC-SOURCE (THCOL) Thermal column. 2145600100014 INC-SPECT Maxwellian neutron spectrum (thermal column). 2145600100015 DETECTOR (COIN,FISCH,BF3) Coincidences between the fission 2145600100016 fragments and the prompt neutrons. Fission chamber 2145600100017 contained 15 cm Ar + 1 cm C-O(2). Ring of 16 BF3 2145600100018 counters embedded in a block of paraffin wax 2145600100019 surrounded the fission chamber. They had a pressure 2145600100020 of 40 cm. Enriched boron-10 (96 perc), 13 cm long * 2145600100021 2.3 cm diam. Sensitive volume. 2145600100022 PART-DET (FF) Fission fragments in coincidence with 2145600100023 (PN) prompt fission neutrons. 2145600100024 CORRECTION Correction for the difference in the 2145600100025 fission neutron spectra of the different isotopes, 2145600100026 which causes a difference in detection efficiency. 2145600100027 ERR-ANALYS (DATA-ERR) Error due to gate length within 2145600100028 statistical error. Quoted error is standard deviation 2145600100029 from the mean of a number of measurements (+ 1% from 2145600100030 the correction on the efficiency for different 2145600100031 fission neutron spectra in the case of the values 2145600100032 derived from relative measurements.) 2145600100033 STATUS (TABLE) Tbl.3 from J.Nucl.En.,2,247,1956 2145600100034 HISTORY (19800310T) G.C. 2145600100035 (20230220U) SD:Updated to new date formats,lower case. 2145600100036 Corrections in all Subents. 2145600100037 ENDBIB 35 0 2145600100038 COMMON 1 3 2145600100039 EN-DUMMY 2145600100040 EV 2145600100041 2.5300E-02 2145600100042 ENDCOMMON 3 0 2145600100043 ENDSUBENT 42 0 2145600199999 SUBENT 21456002 20230220 20231011 2145600200001 BIB 3 6 2145600200002 REACTION ((92-U-233(N,F),PR,NU,,MXW)/ 2145600200003 (92-U-235(N,F),PR,NU,,MXW)) 2145600200004 SAMPLE Back-to-back foils of a few mg of oxide on 2145600200005 Al or Pt backings of about 0.01 cm thickness. 2145600200006 Isotopic enrichments 99.5% (U-233) and 81.2% (U-235). 2145600200007 HISTORY (20230220U) SD: BIB updated. 2145600200008 ENDBIB 6 0 2145600200009 NOCOMMON 0 0 2145600200010 DATA 2 1 2145600200011 DATA DATA-ERR 2145600200012 NO-DIM NO-DIM 2145600200013 1.005 0.016 2145600200014 ENDDATA 3 0 2145600200015 ENDSUBENT 14 0 2145600299999 SUBENT 21456003 20230220 20231011 2145600300001 BIB 3 6 2145600300002 REACTION ((94-PU-239(N,F),PR,NU,,MXW)/ 2145600300003 (92-U-235(N,F),PR,NU,,MXW)) 2145600300004 SAMPLE Back-to-back layers of a few mg of oxide on 2145600300005 Al or Pt backings of about 0.01 cm thickness. 2145600300006 Isotopic enrichment of 99.4%(Pu-239) and 81.2%(U-235).2145600300007 HISTORY (20230220U) SD: BIB updated. 2145600300008 ENDBIB 6 0 2145600300009 NOCOMMON 0 0 2145600300010 DATA 2 1 2145600300011 DATA DATA-ERR 2145600300012 NO-DIM NO-DIM 2145600300013 1.168 0.022 2145600300014 ENDDATA 3 0 2145600300015 ENDSUBENT 14 0 2145600399999 SUBENT 21456004 20230220 20231011 2145600400001 BIB 4 12 2145600400002 REACTION ((94-PU-241(N,F),PR,NU,,MXW)/ 2145600400003 (92-U-235(N,F),PR,NU,,MXW)) 2145600400004 SAMPLE Back-to-back foils of a few mg of oxide on 2145600400005 Al or Pt backings of about 0.01 cm thickness. 2145600400006 Isotopic enrichment of 81.2 perc for the U-235 foil. 2145600400007 The Pu-foil was prepared using highly irradiated Pu 2145600400008 from the nrx pile at chalk river. 2145600400009 It contained 26.8% Pu-239, and 13.9% Pu-241. 2145600400010 CORRECTION A 0.5% correction was made for the spontaneous 2145600400011 fission of Pu-240 and Pu-242. (these have no thermal 2145600400012 fission). 2145600400013 HISTORY (20230220U) SD: BIB updated. 2145600400014 ENDBIB 12 0 2145600400015 NOCOMMON 0 0 2145600400016 DATA 2 1 2145600400017 DATA DATA-ERR 2145600400018 NO-DIM NO-DIM 2145600400019 1.232 0.052 2145600400020 ENDDATA 3 0 2145600400021 ENDSUBENT 20 0 2145600499999 SUBENT 21456005 20230220 20231011 2145600500001 BIB 4 11 2145600500002 REACTION (92-U-235(N,F),PR,NU,,MXW) 2145600500003 SAMPLE 2 Thin walled cylinders of natural uranium, length 2145600500004 10 cm, outer diam 10 cm, 1.93 kg (3.2 mm wall 2145600500005 thickness), and 0.925 kg (1.5 mm wall thickness). 2145600500006 For the U-235 an oxide layer deposited on a Al or Pt 2145600500007 backing of 0.01 mm thickness was used, with an 2145600500008 isotopic enrichment of 81.2%. 2145600500009 METHOD Detection efficiency calibrated by a natural U 2145600500010 source with a spontaneous fission rate of 1.59+-0.09 2145600500011 neutrons/gram*second. 2145600500012 HISTORY (20230220U) SD: BIB updated. 2145600500013 ENDBIB 11 0 2145600500014 NOCOMMON 0 0 2145600500015 DATA 2 1 2145600500016 DATA DATA-ERR 2145600500017 PRT/FIS PRT/FIS 2145600500018 2.45 0.15 2145600500019 ENDDATA 3 0 2145600500020 ENDSUBENT 19 0 2145600599999 SUBENT 21456006 20230220 20231011 2145600600001 BIB 4 7 2145600600002 REACTION (92-U-233(N,F),PR,NU,,MXW) 2145600600003 SAMPLE Back-to-back foils of a few mg of oxide on 2145600600004 Al or Pt backings of about 0.01 cm thickness. 2145600600005 Isotopic enrichments of 81.2% (monitor-foil) 2145600600006 and 99.5% (U-233 foil). 2145600600007 STATUS (DEP,21456002) Ratio 233U/235U 2145600600008 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 2145600600009 ENDBIB 7 0 2145600600010 NOCOMMON 0 0 2145600600011 DATA 2 1 2145600600012 DATA DATA-ERR 2145600600013 PRT/FIS PRT/FIS 2145600600014 2.46 0.15 2145600600015 ENDDATA 3 0 2145600600016 ENDSUBENT 15 0 2145600699999 SUBENT 21456007 20230220 20231011 2145600700001 BIB 4 7 2145600700002 REACTION (94-PU-239(N,F),PR,NU,,MXW) 2145600700003 SAMPLE Back-to-back foils of a few milligrams of oxide on 2145600700004 Al or Pt backings of about 0.01 cm thickness. 2145600700005 Isotopic enrichment 81.2% (monitor-foil) and 2145600700006 99.4% (Pu-239 foil). 2145600700007 STATUS (DEP,21456003) Ratio 239Pu/235U 2145600700008 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 2145600700009 ENDBIB 7 0 2145600700010 NOCOMMON 0 0 2145600700011 DATA 2 1 2145600700012 DATA DATA-ERR 2145600700013 PRT/FIS PRT/FIS 2145600700014 2.86 0.18 2145600700015 ENDDATA 3 0 2145600700016 ENDSUBENT 15 0 2145600799999 SUBENT 21456008 20230220 20231011 2145600800001 BIB 5 12 2145600800002 REACTION (94-PU-241(N,F),PR,NU,,MXW) 2145600800003 SAMPLE Back-to-back foils of a few mg of oxide on 2145600800004 Al or Pt backings of about 0.01 cm thickness. 2145600800005 Isotopic enrichment of the monitor foil 81.2%. 2145600800006 The Pu-foil was prepared using highly irradiated Pu 2145600800007 from the NRX-pile at Chalk River, and contained 26.8% 2145600800008 Pu-239, and 13.9% Pu-241. 2145600800009 CORRECTION A 0.5% correction was made for the spontaneous 2145600800010 fission from Pu-240 and Pu-242 in the sample. (These 2145600800011 isotopes have no thermal fission). 2145600800012 STATUS (DEP,21456004) Ratio 241Pu/235U 2145600800013 HISTORY (20230220A) SD: MONITOR deleted. STATUS added. 2145600800014 ENDBIB 12 0 2145600800015 NOCOMMON 0 0 2145600800016 DATA 2 1 2145600800017 DATA DATA-ERR 2145600800018 PRT/FIS PRT/FIS 2145600800019 3.02 0.21 2145600800020 ENDDATA 3 0 2145600800021 ENDSUBENT 20 0 2145600899999 ENDENTRY 8 0 2145699999999