ENTRY 10086 20170724 14321008600000001 SUBENT 10086001 20170724 14321008600100001 BIB 8 17 1008600100002 TITLE Measurement of the ratios of capture and fission 1008600100003 neutron cross sections of 235U, 238U, and 239Pu at 1008600100004 130 to 1400 keV 1008600100005 AUTHOR (W.P.Poenitz) 1008600100006 INSTITUTE (1USAANL) 1008600100007 REFERENCE (J,NSE,40,383,1970) 1008600100008 (J,ANS,12,279(2),1969) Prelim.239Pu(n,f)/235U(n,f) 1008600100009 in tab. 1008600100010 FACILITY (VDG) 3-MeV Van de Graaff 1008600100011 INC-SOURCE (P-LI7) Metallic Li (10 to 20 keV thick at lower than 1008600100012 300 keV to 50 to 80 keV thick at higher energies) 1008600100013 evaporated on Ta backing (0.025 cm thick) 1008600100014 STATUS (APRVD) Approved by author 1008600100015 HISTORY (19701208C) 1008600100016 (19811125A) Converted to REACTION formalism 1008600100017 (19991013A) Converted to new data formalism. 1008600100018 (20170724A) On. Major rev. in 002-005. 006-008 added. 1008600100019 ENDBIB 17 0 1008600100020 NOCOMMON 0 0 1008600100021 ENDSUBENT 20 0 1008600199999 SUBENT 10086002 20170724 14321008600200001 BIB 12 33 1008600200002 REACTION ((92-U-238(N,G)92-U-239,,SIG)/(92-U-235(N,F),,SIG)) 1008600200003 DECAY-DATA (92-U-239,23.MIN) 1008600200004 (93-NP-239,2.35D,DG,278.) 1008600200005 RAD-DET (93-NP-239,DG) 1008600200006 SAMPLE 238U foil sandwiched between two 235U foils. 1008600200007 238U: Metallic U foils (0.0125 cm thick, 1.6 cm diam.) 1008600200008 depleted to 0.4% 235U). 1008600200009 235U: Two 235U foils (250 ug/cm2 thick) on Mo backings 1008600200010 (0.013 cm thick) 1008600200011 METHOD (ACTIV) for 238U(n,g)239U 1008600200012 DETECTOR (FISCH) Low mass fission ionization chamber 1008600200013 (GELI) 30 cm3 Ge(Li) gamma counter 1008600200014 MONITOR ((92-U-238(N,G)92-U-239,,SIG)/(92-U-235(N,F),,SIG)) 1008600200015 0.00473+/-0.00008 b 1008600200016 MONIT-REF (,J.R.Stehn+,R,BNL-325,1965) 2nd ed. Suppl. No.2 1008600200017 CORRECTION Corrections due to neutron scattered elastically in 1008600200018 the foils and fission counter walls were eliminated 1008600200019 in the first order. 1008600200020 - Contribution of thermal or epithermal neutrons 1008600200021 (negligible), 1008600200022 - Neutrons scattered in the target backing and the 1008600200023 beam tube (~5%), 1008600200024 - Lower energy 7Li(p,n1)7Be neutron (up to 6%), 1008600200025 - Fission neutron contributions (<1%, neglected). 1008600200026 ERR-ANALYS (ERR-T) Uncertainty due to 1008600200027 (ERR-S,1.,2.) Statistics (1-2%) 1008600200028 (ERR-1) Normalization procedure (2%) 1008600200029 (ERR-2,0.,3.) Correction uncertainties (0-3%) 1008600200030 (ERR-3,0.,1.) Energy uncertainties (0-1%) 1008600200031 STATUS (TABLE) Table I of Nucl.Sci.Eng.40(1970)383 1008600200032 (SPSDD,10086006) Renormalized 1.3% for 235U mass and 1008600200033 238U time factor 1008600200034 HISTORY (20170724A) On. Superseded. 1008600200035 ENDBIB 33 0 1008600200036 COMMON 3 3 1008600200037 EN-NRM MONIT ERR-1 1008600200038 EV B PER-CENT 1008600200039 0.0253 0.00473 2. 1008600200040 ENDCOMMON 3 0 1008600200041 DATA 3 12 1008600200042 EN DATA ERR-T 1008600200043 KEV NO-DIM NO-DIM 1008600200044 130. 0.126 0.006 1008600200045 150. 0.126 0.006 1008600200046 250. 0.114 0.004 1008600200047 300. 0.103 0.003 1008600200048 400. 0.104 0.003 1008600200049 500. 0.111 0.003 1008600200050 600. 0.122 0.004 1008600200051 700. 0.133 0.004 1008600200052 900. 0.124 0.004 1008600200053 1200. 0.097 0.004 1008600200054 1250. 0.092 0.004 1008600200055 1400. 0.074 0.003 1008600200056 ENDDATA 14 0 1008600200057 ENDSUBENT 56 0 1008600299999 SUBENT 10086003 20170724 14321008600300001 BIB 11 38 1008600300002 REACTION ((92-U-238(N,G)92-U-239,,SIG)/(94-PU-239(N,F),,SIG)) 1008600300003 DECAY-DATA (92-U-239,23.MIN) 1008600300004 (93-NP-239,2.35D,DG,278.) 1008600300005 RAD-DET (93-NP-239,DG) 1008600300006 SAMPLE 238U: Metallic U foils (0.0125 cm thick, 1.6 cm diam.) 1008600300007 depleted to 0.4% 235U). 1008600300008 239Pu: 239Pu foil layer (25 ug/cm2 239Pu thick, 1008600300009 99.95 wt%) electro-deposited on steel backing 1008600300010 METHOD (ACTIV) for 238U(n,g)239U 1008600300011 DETECTOR Capture gamma counter and fission counter in back-to- 1008600300012 back arrangement. 1008600300013 (FISCH) Low mass fission ionization chamber 1008600300014 (GELI) 30 cm3 Ge(Li) gamma counter 1008600300015 MONITOR Absolute fission rate from extrapolation of fission- 1008600300016 fragment energy spectra to zero pulse height and 1008600300017 correcting for total absorption. 1008600300018 Amount of fissile material from low geometry alpha 1008600300019 counting. 1008600300020 Absolute Ge(Li) efficiency from calibrated 243Am 1008600300021 sample in equilibrium with 239Np daughter. 1008600300022 CORRECTION - Elastic scattering in counter (1%), 1008600300023 - Contribution of thermal or epithermal neutrons 1008600300024 (negligible), 1008600300025 - Neutrons scattered in the target backing and the 1008600300026 beam tube (~5%), 1008600300027 - Lower energy 7Li(p,n1)7Be neutron (up to 6%), 1008600300028 - Fission neutron contributions (<1%, neglected). 1008600300029 - gamma absorption in uranium foil (9%) 1008600300030 ERR-ANALYS (ERR-T) Uncertainty due to: 1008600300031 (ERR-S,1.,2.) Statistics (1-2%)1008600300032 (ERR-1) Normalization procedure (2%)1008600300033 (ERR-2,0.,3.) Correction uncertainties (0-3%)1008600300034 (ERR-3,0.,1.) Energy uncertainties (0-1%)1008600300035 (ERR-4) Absolute fission & capture determination (2.5%)1008600300036 STATUS (TABLE) Table II of Nucl.Sci.Eng.40(1970)383 1008600300037 (SPSDD,10086007) Renormalized 1.8% for 239Pu mass and 1008600300038 238U time factor 1008600300039 HISTORY (20170724A) On. Superseded. 1008600300040 ENDBIB 38 0 1008600300041 COMMON 2 3 1008600300042 ERR-1 ERR-4 1008600300043 PER-CENT PER-CENT 1008600300044 2. 2.5 1008600300045 ENDCOMMON 3 0 1008600300046 DATA 3 5 1008600300047 EN DATA ERR-T 1008600300048 KEV NO-DIM NO-DIM 1008600300049 400. 0.082 0.003 1008600300050 500. 0.082 0.002 1008600300051 700. 0.087 0.003 1008600300052 900. 0.086 0.003 1008600300053 1400. 0.048 0.002 1008600300054 ENDDATA 7 0 1008600300055 ENDSUBENT 54 0 1008600399999 SUBENT 10086004 20170724 14321008600400001 BIB 9 26 1008600400002 REACTION ((94-PU-239(N,F),,SIG)/(92-U-235(N,F),,SIG)) 1008600400003 SAMPLE 239Pu and 235U foils mounted back-to-back. 1008600400004 239Pu: 239Pu foil (25 ug/cm2 239Pu (99.95 weight-%), 1008600400005 electro-deposited on steel backing. 1008600400006 235U: 235U foils (~150 ug/cm2 thick) on Mo backings 1008600400007 (0.013 cm thick) 1008600400008 METHOD (TOF) for low energy background neutron supression 1008600400009 DETECTOR (SCIN) Double chamber gas scintillation counter 1008600400010 MONITOR Absolute fission rates from extrapolation of fission- 1008600400011 fragment energy spectra to zero pulse height and 1008600400012 correcting for total absorption. 1008600400013 Amount of fissile material from low geometry alpha 1008600400014 counting. 1008600400015 CORRECTION Corrected for 1008600400016 - extrapolation to zero pulse height (1.5% for 239Pu, 1008600400017 same order for 235U), 1008600400018 - total absorption of both fragments (1.2% for 235U, 1008600400019 0.2% for 239Pu), 1008600400020 - scattering in backings and counter (small). 1008600400021 ERR-ANALYS (ERR-T) Uncertainty due to: 1008600400022 (ERR-S,1.,2.) Statistics (1-2%)1008600400023 (ERR-1) Amounts of fissile materials (1.5%)1008600400024 (ERR-2,1.,2.) Corrections & energy determination (1-2%)1008600400025 STATUS (TABLE) Table III of Nucl.Sci.Eng.40(1970)383 1008600400026 (SPSDD,10086008) 1008600400027 HISTORY (20170724A) On. Superseded by 10086.008. 1008600400028 ENDBIB 26 0 1008600400029 COMMON 1 3 1008600400030 ERR-1 1008600400031 PER-CENT 1008600400032 1.5 1008600400033 ENDCOMMON 3 0 1008600400034 DATA 3 11 1008600400035 EN DATA ERR-T 1008600400036 KEV NO-DIM NO-DIM 1008600400037 150. 0.958 0.024 1008600400038 200. 1.072 0.031 1008600400039 250. 1.080 0.032 1008600400040 325. 1.191 0.030 1008600400041 500. 1.320 0.027 1008600400042 700. 1.429 0.026 1008600400043 850. 1.461 0.041 1008600400044 1000. 1.356 0.031 1008600400045 1200. 1.420 0.050 1008600400046 1300. 1.418 0.031 1008600400047 1400. 1.446 0.029 1008600400048 ENDDATA 13 0 1008600400049 ENDSUBENT 48 0 1008600499999 SUBENT 10086005 20170724 14321008600500001 BIB 8 12 1008600500002 REACTION ((92-U-238(N,G)92-U-239,,SIG)/(92-U-235(N,F),,SIG)) 1008600500003 DECAY-DATA (92-U-239,23.MIN) 1008600500004 (93-NP-239,2.35D,DG,278.) 1008600500005 SAMPLE Several 235U foils 1008600500006 DETECTOR (GELI) Several Ge(Li) foils which calibration checked 1008600500007 by independently calibrated 243Am source 1008600500008 METHOD (ACTIV) for 238U(n,g)239U 1008600500009 ERR-ANALYS (DATA-ERR) No information on source of uncertainty 1008600500010 FLAG (1.) Absolute determination of counting efficiencies. 1008600500011 (2.) Counting efficiencies eliminated by thermal 1008600500012 cross sections. 1008600500013 STATUS (TABLE) Table V of Nucl.Sci.Eng.40(1970)383 1008600500014 ENDBIB 12 0 1008600500015 COMMON 1 3 1008600500016 EN 1008600500017 KEV 1008600500018 500. 1008600500019 ENDCOMMON 3 0 1008600500020 DATA 3 4 1008600500021 DATA DATA-ERR FLAG 1008600500022 NO-DIM NO-DIM NO-DIM 1008600500023 0.110 0.003 1. 1008600500024 0.109 0.003 1. 1008600500025 0.111 0.003 2. 1008600500026 0.108 0.008 2. 1008600500027 ENDDATA 6 0 1008600500028 ENDSUBENT 27 0 1008600599999 SUBENT 10086006 20170724 14321008600600001 BIB 9 26 1008600600002 REACTION ((92-U-238(N,G)92-U-239,,SIG)/(92-U-235(N,F),,SIG)) 1008600600003 RAD-DET (93-NP-239,DG) 1008600600004 SAMPLE 238U foil sandwiched between two 235U foils. 1008600600005 238U: Metallic U foils (0.0125 cm thick, 1.6 cm diam.) 1008600600006 depleted to 0.4% 235U). 1008600600007 235U: Two 235U foils (250 ug/cm2 thick) on Mo backings 1008600600008 (0.013 cm thick) 1008600600009 METHOD (ACTIV) for 238U(n,g)239U 1008600600010 DETECTOR (FISCH) Low mass fission ionization chamber 1008600600011 (GELI) 30 cm3 Ge(Li) gamma counter 1008600600012 ERR-ANALYS (ERR-T) Total uncertainty from 1008600600013 (ERR-S) Statistics (1.0%-1.4%)1008600600014 (ERR-1,,,F) 235U mass (3.0%)1008600600015 (ERR-2,,,F) 239Np decay calibration (2.5%)1008600600016 (ERR-3,,,P) Self-shielding and scattering (1.0%-2.0%)1008600600017 (ERR-4,,,P) Background (0.2%-2.0%)1008600600018 (ERR-5,,,P) Fission fragment detection (0.5%-0.9%)1008600600019 (ERR-6,,,P) Neutron scattering from fission chamber and1008600600020 target (1.0%-1.9%)1008600600021 (ERR-7,,,P)Fission fragment gamma background(1.0%-3.7%)1008600600022 COMMENT By compiler: 1008600600023 Poenitz separately compiles 14 data points of 1008600600024 238U(n,f)/235U(n,f) ratio shape in thermal to 1.4 MeV 1008600600025 in GMA input #405. 1008600600026 STATUS (PENTZ) GMA input #406 1008600600027 HISTORY (20170724C) On 1008600600028 ENDBIB 26 0 1008600600029 COMMON 2 3 1008600600030 ERR-1 ERR-2 1008600600031 PER-CENT PER-CENT 1008600600032 3.0 2.5 1008600600033 ENDCOMMON 3 0 1008600600034 DATA 11 5 1008600600035 EN EN-ERR EN-RSL-HW DATA ERR-T ERR-S 1008600600036 ERR-3 ERR-4 ERR-5 ERR-6 ERR-7 1008600600037 KEV PER-CENT PER-CENT NO-DIM PER-CENT PER-CENT 1008600600038 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 1008600600039 30. 3.5 23.3 0.2019 4.4 1.0 1008600600040 1.0 0.2 0.5 1.0 1.0 1008600600041 130. 2.3 15.0 0.1172 5.3 1.1 1008600600042 2.0 2.0 0.6 1.1 1.3 1008600600043 500. 1.5 10.0 0.1073 5.8 1.2 1008600600044 2.0 2.0 0.7 1.5 2.5 1008600600045 500. 1.5 10.0 0.1083 5.8 1.2 1008600600046 2.0 2.0 0.7 1.5 2.5 1008600600047 900. 1.8 12.0 0.1241 6.6 1.4 1008600600048 2.0 2.0 0.9 1.9 3.7 1008600600049 ENDDATA 14 0 1008600600050 ENDSUBENT 49 0 1008600699999 SUBENT 10086007 20170724 14321008600700001 BIB 8 24 1008600700002 REACTION ((92-U-238(N,G)92-U-239,,SIG)/(94-PU-239(N,F),,SIG)) 1008600700003 RAD-DET (93-NP-239,DG) 1008600700004 SAMPLE 238U: Metallic U foils (0.0125 cm thick, 1.6 cm diam.) 1008600700005 depleted to 0.4% 235U). 1008600700006 239Pu: 239Pu foil layer (25 ug/cm2 239Pu thick, 1008600700007 99.95 wt%) electro-deposited on steel backing 1008600700008 METHOD (ACTIV) for 238U(n,g)239U 1008600700009 DETECTOR Capture gamma counter and fission counter in back-to- 1008600700010 back arrangement. 1008600700011 (FISCH) Low mass fission ionization chamber 1008600700012 (GELI) 30 cm3 Ge(Li) gamma counter 1008600700013 ERR-ANALYS (ERR-T) Total uncertainty from 1008600700014 (ERR-S) Statistics 1008600700015 (ERR-1,,,F) 239Pu mass (1.0%)1008600700016 (ERR-2,,,F) 239Np decay calibration (2.5%)1008600700017 (ERR-3,,,P) Neutron scattering (2.0%)1008600700018 (ERR-4,,,P) Neutron background (2.0%)1008600700019 (ERR-5,,,P) Fission fragment detection (0.6%-1.0%)1008600700020 (ERR-6,,,P) Neutron scattering from fissionamber 1008600700021 and target (1.2%-1.9%)1008600700022 (ERR-7,,,P)Fission fragment gamma background(1.8%-4.7%)1008600700023 (ERR-8,,,P) 7Li(p,n1)7Be low energy neutron (0.1%-1.8%)1008600700024 STATUS (PENTZ) GMA input #407 1008600700025 HISTORY (20170724C) On 1008600700026 ENDBIB 24 0 1008600700027 COMMON 4 3 1008600700028 ERR-1 ERR-2 ERR-3 ERR-4 1008600700029 PER-CENT PER-CENT PER-CENT PER-CENT 1008600700030 1.0 2.5 2.0 2.0 1008600700031 ENDCOMMON 3 0 1008600700032 DATA 10 5 1008600700033 EN EN-ERR EN-RSL-HW DATA ERR-T ERR-S 1008600700034 ERR-5 ERR-6 ERR-7 ERR-8 1008600700035 KEV PER-CENT PER-CENT NO-DIM PER-CENT PER-CENT 1008600700036 PER-CENT PER-CENT PER-CENT PER-CENT 1008600700037 400. 0.8 5.0 0.08052 4.6 1.0 1008600700038 0.6 1.2 1.8 0.1 1008600700039 500. 0.8 5.2 0.08052 4.8 1.1 1008600700040 0.6 1.3 2.1 0.1 1008600700041 700. 0.8 5.6 0.08543 5.1 1.1 1008600700042 0.7 1.4 2.7 0.1 1008600700043 900. 0.9 5.9 0.08445 5.6 1.2 1008600700044 0.8 1.6 3.3 0.6 1008600700045 1400. 1.0 6.8 0.04714 6.9 1.5 1008600700046 1.0 1.9 4.7 1.8 1008600700047 ENDDATA 14 0 1008600700048 ENDSUBENT 47 0 1008600799999 SUBENT 10086008 20170724 14321008600800001 BIB 7 20 1008600800002 REACTION ((94-PU-239(N,F),,SIG)/(92-U-235(N,F),,SIG)) 1008600800003 SAMPLE 239Pu and 235U foils mounted back-to-back. 1008600800004 239Pu: 239Pu foil (25 ug/cm2 239Pu (99.95 weight-%), 1008600800005 electro-deposited on steel backing. 1008600800006 235U: 235U foils (~150 ug/cm2 thick) on Mo backings 1008600800007 (0.013 cm thick) 1008600800008 METHOD (TOF) for low energy background neutron supression 1008600800009 DETECTOR (SCIN) Double chamber gas scintillation counter 1008600800010 ERR-ANALYS (ERR-T) Total uncertainty from 1008600800011 (ERR-S) Statistics (0.8%-2.1%)1008600800012 (ERR-1,,,F) 235U mass (3.0%)1008600800013 (ERR-2,,,F) 239Pu mass (0.5%)1008600800014 (ERR-3,,,P) Fission fragment absorption (0.5%-1.4%)1008600800015 (ERR-4,,,P) Fission fragment extrapolation (0.5%)1008600800016 (ERR-5,,,P) 7Li(p,n1)7Be low energy neutrons(0.1%-0.7%)1008600800017 (ERR-6,,,P) Background (2.0%)1008600800018 (ERR-7,,,P) Non 235U fission (0.1%-0.5%)1008600800019 (ERR-8,,,P) Neutron scattering (1.0%)1008600800020 STATUS (PENTZ) GMA input #626 1008600800021 HISTORY (20170724C) On 1008600800022 ENDBIB 20 0 1008600800023 COMMON 5 3 1008600800024 ERR-1 ERR-2 ERR-4 ERR-6 ERR-8 1008600800025 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 1008600800026 3.0 0.5 0.5 2.0 1.0 1008600800027 ENDCOMMON 3 0 1008600800028 DATA 9 11 1008600800029 EN EN-ERR EN-RSL-HW DATA ERR-T ERR-S 1008600800030 ERR-3 ERR-5 ERR-7 1008600800031 KEV PER-CENT PER-CENT NO-DIM PER-CENT PER-CENT 1008600800032 PER-CENT PER-CENT PER-CENT 1008600800033 150. 1.0 6.7 0.958 4.0 1.0 1008600800034 0.5 0.1 0.1 1008600800035 200. 0.8 5.0 1.072 4.0 1.1 1008600800036 0.5 0.1 0.1 1008600800037 250. 3.0 20.0 1.080 4.0 1.1 1008600800038 0.6 0.1 0.1 1008600800039 325. 2.3 15.4 1.191 4.0 0.9 1008600800040 0.6 0.1 0.2 1008600800041 500. 2.4 16.0 1.320 4.0 0.9 1008600800042 0.8 0.1 0.2 1008600800043 700. 1.1 7.1 1.429 4.0 0.8 1008600800044 0.9 0.1 0.3 1008600800045 850. 1.2 8.2 1.461 4.5 2.1 1008600800046 1.0 0.2 0.3 1008600800047 1000. 1.2 8.0 1.356 4.2 1.1 1008600800048 1.1 0.4 0.4 1008600800049 1200. 1.0 6.7 1.420 4.6 2.1 1008600800050 1.3 0.5 0.4 1008600800051 1300. 1.0 6.5 1.418 4.3 1.1 1008600800052 1.4 0.6 0.4 1008600800053 1400. 0.9 6.1 1.446 4.3 1.0 1008600800054 1.4 0.7 0.5 1008600800055 ENDDATA 26 0 1008600800056 ENDSUBENT 55 0 1008600899999 ENDENTRY 8 0 1008699999999