ENTRY 14851 20250523 152314851000 1 SUBENT 14851001 20250523 152314851001 1 BIB 14 84 14851001 2 TITLE Remeasurement of the 239Pu(n,f)/235U(n,f) Cross- 14851001 3 Section Ratio with the NIFFTE fission Time Projection 14851001 4 Chamber Using Vapor-deposited Targets 14851001 5 AUTHOR (D.H.Dongwi,L.Snyder,V.Aguilar,N.Androski, 14851001 6 M.Anastasiou,N.S.Bowden,A.Chemey,T.Classen, 14851001 7 J.E.Fuzaro Alencar,U.Greife,M.Haseman,L.D.Isenhower, 14851001 8 J.L.Klay,W.Loveland,M.P.Mendenhall,M.Monterial, 14851001 9 C.Prokop,M.Silveira,T.S.Watson,L.Yao) 14851001 10 REFERENCE (J,NDS,202,30,2025) 14851001 11 #doi:10.1016/j.nds.2025.04.003 14851001 12 REL-REF (O,14721002,L.Snyder+,J,NDS,178,1,2021) Previous result14851001 13 (I,,L.Snyder+,J,NIM/A,1021,165864,2022) NIFTE TPC 14851001 14 characterization. 14851001 15 INSTITUTE (1USALRL,1USAORU,1USACSM,1USALAS) 14851001 16 (1USAUSA) California Polytechnic State University, San 14851001 17 Luis Obispo, CA 93407, United States 14851001 18 (1USAUSA) Abilene Christian University, Abilene, 14851001 19 TX 79699, United States 14851001 20 FACILITY (LINAC,1USALAS) The Los Alamos Neutron Science Center 14851001 21 (LANSCE) Weapons Neutron Science (WNR) facility. 14851001 22 INC-SOURCE (SPALL) 14851001 23 INC-SPECT The LANSCE facility makes use of an 800 MeV proton 14851001 24 accelerator to provide a pulsed white neutron source. 14851001 25 For this experiment LANSCE delivered 100 Hz pulses, 14851001 26 each approximately 625 microsec in length, containing 14851001 27 micro-pulses separated by 1.8 microsec. 14851001 28 DETECTOR (TPC) The fissionTPC is a two-volume MICROMEGAS TPC, 14851001 29 operated using a gas mixture of high-purity argon and 14851001 30 5% isobutane at 550 torr, with actinide targets 14851001 31 mounted onto the central cathode. 14851001 32 SAMPLE Three samples were prepared from a single source by 14851001 33 pipetting a small volume of acid onto the source and 14851001 34 removing it to a separate vial. Sample solutions were 14851001 35 purified using standard methods and analyzed by 14851001 36 MC-ICP-MS. 14851001 37 Sample #1: 14851001 38 (92-U-235,ENR=0.9989375) 14851001 39 (92-U-234,ENR=0.0002891) 14851001 40 (92-U-236,ENR=0.0001586) 14851001 41 (92-U-238,ENR=0.0006149) 14851001 42 (94-PU-239,ENR=0.999356) 14851001 43 (94-PU-240,ENR=0.0004721) 14851001 44 (94-PU-241,ENR=0.0000708) 14851001 45 (94-PU-242,ENR=0.0001007) 14851001 46 Sample #2: 14851001 47 (92-U-235,ENR=0.9989159) 14851001 48 (92-U-234,ENR=0.0002894) 14851001 49 (92-U-236,ENR=0.0001581) 14851001 50 (92-U-238,ENR=0.0006366) 14851001 51 (94-PU-239,ENR=0.9993324) 14851001 52 (94-PU-240,ENR=0.0004816) 14851001 53 (94-PU-241,ENR=0.0000725) 14851001 54 (94-PU-242,ENR=0.0001135) 14851001 55 Sample #3: 14851001 56 (92-U-235,ENR=0.9989276) 14851001 57 (92-U-234,ENR=0.0002895) 14851001 58 (92-U-236,ENR=0.0001586) 14851001 59 (92-U-238,ENR=0.0006243) 14851001 60 (94-PU-239,ENR=0.9993419) 14851001 61 (94-PU-240,ENR=0.0004773) 14851001 62 (94-PU-241,ENR=0.0000705) 14851001 63 (94-PU-242,ENR=0.0001104) 14851001 64 METHOD (TOF) The 90L flight path. Experiments to measure 14851001 65 fission cross-section ratios are typically arranged 14851001 66 so that the two targets share the same beam, to 14851001 67 ensure that the neutron flux term in ratio cancels out.14851001 68 CORRECTION Following corrections were applied 14851001 69 - wraparound correction 14851001 70 - efficiency correction 14851001 71 - contamination correction 14851001 72 - overlap correction 14851001 73 - beam attenuation and scattering correction 14851001 74 ERR-ANALYS (ERR-T) The absolute, total uncertainty is 1 sigma. 14851001 75 (ERR-S) Statistical uncertainty. 14851001 76 (ERR-1) From the variational analysis. 14851001 77 (ERR-2) The wraparound correction. 14851001 78 (ERR-3) The efficiency correction. 14851001 79 (ERR-4) The contamination correction. 14851001 80 (ERR-5) The overlap correction. 14851001 81 (ERR-6) The beam attenuation and scattering correction.14851001 82 (ERR-7) The normalization correction uncertainty is 14851001 83 0.79%. The normalization uncertainty is energy 14851001 84 independent. 14851001 85 HISTORY (20250523C) BP 14851001 86 ENDBIB 84 0 14851001 87 COMMON 1 3 14851001 88 ERR-7 14851001 89 PER-CENT 14851001 90 0.79 14851001 91 ENDCOMMON 3 0 14851001 92 ENDSUBENT 91 0 1485100199999 SUBENT 14851002 20250523 152314851002 1 BIB 2 2 14851002 2 REACTION ((94-PU-239(N,F),,SIG)/(92-U-235(N,F),,SIG)) 14851002 3 STATUS (TABLE,,D.H.Dongwi+,J,NDS,202,30,2025) Table 3-4 14851002 4 ENDBIB 2 0 14851002 5 NOCOMMON 0 0 14851002 6 DATA 12 119 14851002 7 EN-MIN EN-MAX EN-RSL-FW DATA ERR-T ERR-S 14851002 8 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 14851002 9 MEV MEV MEV NO-DIM PER-CENT PER-CENT 14851002 10 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 14851002 11 0.1059 0.1122 0.00628 0.963 2.9 1.614851002 12 1.5 0.6 0.19 0.099 0.54 0.1414851002 13 0.1122 0.1189 0.00665 0.95 2.7 1.614851002 14 1.7 0.54 0.22 0.12 0.58 0.1314851002 15 0.1189 0.1259 0.00704 0.9957 2.5 1.414851002 16 1. 0.45 0.21 0.13 0.48 0.1414851002 17 0.1259 0.1334 0.00746 0.9815 2.4 1.414851002 18 1.3 0.41 0.23 0.11 0.46 0.1214851002 19 0.1334 0.1413 0.0079 1.045 2.1 1.314851002 20 1.1 0.35 0.2 0.082 0.48 0.1214851002 21 0.1413 0.1496 0.00837 1.071 2.2 1.314851002 22 0.99 0.35 0.2 0.057 0.53 0.1414851002 23 0.1496 0.1585 0.00887 1.098 1.9 1.114851002 24 0.83 0.28 0.2 0.057 0.47 0.1214851002 25 0.1585 0.1679 0.00939 1.083 1.8 1.114851002 26 1.2 0.26 0.2 0.064 0.38 0.1214851002 27 0.1679 0.1778 0.00995 1.091 1.8 1.114851002 28 1. 0.24 0.22 0.066 0.46 0.1114851002 29 0.1778 0.1884 0.0105 1.13 1.6 1.14851002 30 0.82 0.21 0.22 0.06 0.39 0.09814851002 31 0.1884 0.1995 0.0112 1.079 1.7 1.14851002 32 0.82 0.22 0.2 0.053 0.41 0.1114851002 33 0.1995 0.2113 0.0118 1.134 1.5 0.9314851002 34 0.76 0.18 0.2 0.051 0.37 0.09814851002 35 0.2113 0.2239 0.0125 1.187 1.5 0.9114851002 36 0.74 0.17 0.2 0.053 0.38 0.08314851002 37 0.2239 0.2371 0.0133 1.202 1.4 0.8614851002 38 0.64 0.16 0.19 0.055 0.34 0.08414851002 39 0.2371 0.2512 0.0141 1.166 1.4 0.8414851002 40 0.65 0.15 0.19 0.055 0.33 0.0914851002 41 0.2512 0.2661 0.0149 1.198 1.3 0.8114851002 42 0.57 0.14 0.2 0.053 0.32 0.09714851002 43 0.2661 0.2818 0.0158 1.263 1.2 0.7614851002 44 0.54 0.13 0.21 0.05 0.33 0.06414851002 45 0.2818 0.2985 0.0167 1.272 1.2 0.7514851002 46 0.45 0.12 0.19 0.049 0.31 0.0714851002 47 0.2985 0.3162 0.0177 1.266 1.2 0.6914851002 48 0.45 0.1 0.21 0.049 0.34 0.07414851002 49 0.3162 0.335 0.0187 1.282 1.1 0.6914851002 50 0.4 0.1 0.19 0.05 0.31 0.06814851002 51 0.335 0.3548 0.0198 1.293 1.1 0.6314851002 52 0.36 0.089 0.23 0.049 0.26 0.06414851002 53 0.3548 0.3758 0.021 1.292 1. 0.6314851002 54 0.34 0.082 0.22 0.048 0.28 0.0714851002 55 0.3758 0.3981 0.0223 1.306 1. 0.6114851002 56 0.34 0.077 0.2 0.047 0.25 0.08814851002 57 0.3981 0.4217 0.0236 1.305 1. 0.5914851002 58 0.31 0.074 0.18 0.048 0.25 0.05814851002 59 0.4217 0.4467 0.025 1.363 1. 0.5814851002 60 0.32 0.073 0.19 0.048 0.25 0.06214851002 61 0.4467 0.4732 0.0265 1.402 1. 0.5514851002 62 0.37 0.067 0.19 0.049 0.26 0.05414851002 63 0.4732 0.5012 0.028 1.407 0.98 0.5414851002 64 0.26 0.062 0.2 0.05 0.25 0.05614851002 65 0.5012 0.5309 0.0297 1.416 0.95 0.514851002 66 0.26 0.057 0.2 0.05 0.23 0.05614851002 67 0.5309 0.5623 0.0315 1.422 0.97 0.514851002 68 0.29 0.048 0.21 0.05 0.25 0.05614851002 69 0.5623 0.5957 0.0333 1.42 0.93 0.4914851002 70 0.24 0.046 0.23 0.05 0.22 0.06614851002 71 0.5957 0.631 0.0353 1.475 0.91 0.4714851002 72 0.21 0.04 0.2 0.05 0.2 0.05214851002 73 0.631 0.6683 0.0374 1.472 0.91 0.4514851002 74 0.24 0.042 0.21 0.05 0.23 0.05814851002 75 0.6683 0.7079 0.0396 1.486 0.92 0.4514851002 76 0.25 0.042 0.18 0.05 0.19 0.05214851002 77 0.7079 0.7499 0.0419 1.496 0.92 0.4414851002 78 0.22 0.037 0.19 0.049 0.2 0.05414851002 79 0.7499 0.7943 0.0444 1.546 0.9 0.4314851002 80 0.2 0.037 0.21 0.049 0.21 0.04614851002 81 0.7943 0.8414 0.0471 1.569 0.92 0.4214851002 82 0.2 0.033 0.22 0.05 0.2 0.05214851002 83 0.8414 0.8913 0.0499 1.525 0.91 0.4114851002 84 0.22 0.03 0.2 0.049 0.22 0.03914851002 85 0.8913 0.9441 0.0528 1.487 0.91 0.4114851002 86 0.24 0.027 0.21 0.048 0.18 0.03814851002 87 0.9441 1. 0.0559 1.456 0.86 0.414851002 88 0.22 0.026 0.21 0.046 0.2 0.0414851002 89 1. 1.059 0.0593 1.458 0.89 0.414851002 90 0.22 0.024 0.22 0.046 0.2 0.03914851002 91 1.059 1.122 0.0628 1.486 0.89 0.3914851002 92 0.24 0.023 0.2 0.046 0.19 0.0414851002 93 1.122 1.189 0.0665 1.504 0.86 0.3914851002 94 0.21 0.021 0.2 0.046 0.18 0.04614851002 95 1.189 1.259 0.0704 1.54 0.87 0.3914851002 96 0.21 0.02 0.19 0.045 0.19 0.04114851002 97 1.259 1.334 0.0746 1.568 0.86 0.3814851002 98 0.26 0.022 0.18 0.044 0.19 0.04214851002 99 1.334 1.413 0.079 1.6 0.89 0.3814851002 100 0.22 0.021 0.21 0.043 0.23 0.03414851002 101 1.413 1.496 0.0837 1.603 0.88 0.3814851002 102 0.22 0.018 0.2 0.042 0.2 0.04214851002 103 1.496 1.585 0.0887 1.594 0.86 0.3814851002 104 0.21 0.017 0.19 0.041 0.17 0.08214851002 105 1.585 1.679 0.0939 1.569 0.88 0.3814851002 106 0.19 0.018 0.22 0.04 0.19 0.03914851002 107 1.679 1.778 0.0995 1.587 0.83 0.3814851002 108 0.28 0.017 0.23 0.039 0.18 0.0414851002 109 1.778 1.884 0.105 1.555 0.86 0.3814851002 110 0.19 0.017 0.17 0.038 0.18 0.04714851002 111 1.884 1.995 0.112 1.569 0.86 0.3814851002 112 0.23 0.017 0.19 0.036 0.18 0.03614851002 113 1.995 2.113 0.118 1.585 0.88 0.3714851002 114 0.23 0.015 0.21 0.035 0.17 0.04114851002 115 2.113 2.239 0.125 1.576 0.87 0.3814851002 116 0.21 0.014 0.18 0.034 0.18 0.04614851002 117 2.239 2.371 0.133 1.557 0.88 0.3814851002 118 0.22 0.013 0.21 0.033 0.19 0.03714851002 119 2.371 2.512 0.141 1.56 0.87 0.3914851002 120 0.2 0.015 0.21 0.032 0.19 0.04114851002 121 2.512 2.661 0.149 1.552 0.89 0.3914851002 122 0.21 0.014 0.2 0.031 0.19 0.03214851002 123 2.661 2.818 0.158 1.555 0.88 0.3914851002 124 0.2 0.013 0.2 0.029 0.22 0.03914851002 125 2.818 2.985 0.167 1.554 0.88 0.414851002 126 0.21 0.014 0.17 0.028 0.2 0.04814851002 127 2.985 3.162 0.177 1.562 0.86 0.414851002 128 0.24 0.013 0.2 0.027 0.17 0.0414851002 129 3.162 3.35 0.187 1.565 0.89 0.414851002 130 0.22 0.013 0.21 0.026 0.2 0.0414851002 131 3.35 3.548 0.198 1.584 0.9 0.4114851002 132 0.22 0.014 0.18 0.025 0.22 0.03814851002 133 3.548 3.758 0.21 1.607 0.91 0.4214851002 134 0.17 0.014 0.2 0.023 0.22 0.04614851002 135 3.758 3.981 0.223 1.576 0.89 0.4114851002 136 0.23 0.013 0.19 0.022 0.21 0.04214851002 137 3.981 4.217 0.236 1.581 0.89 0.4314851002 138 0.23 0.012 0.19 0.021 0.21 0.04214851002 139 4.217 4.467 0.25 1.59 0.91 0.4414851002 140 0.2 0.012 0.2 0.02 0.16 0.0414851002 141 4.467 4.732 0.265 1.601 0.91 0.4514851002 142 0.24 0.013 0.2 0.02 0.22 0.03714851002 143 4.732 5.012 0.28 1.607 0.9 0.4614851002 144 0.18 0.013 0.18 0.02 0.22 0.03614851002 145 5.012 5.309 0.297 1.598 0.92 0.4714851002 146 0.19 0.014 0.19 0.021 0.2 0.0414851002 147 5.309 5.623 0.315 1.657 0.92 0.4814851002 148 0.21 0.013 0.18 0.022 0.21 0.03614851002 149 5.623 5.957 0.333 1.653 0.94 0.4914851002 150 0.23 0.013 0.16 0.023 0.22 0.03714851002 151 5.957 6.31 0.353 1.592 0.95 0.4814851002 152 0.2 0.012 0.19 0.022 0.22 0.04114851002 153 6.31 6.683 0.374 1.503 0.88 0.4614851002 154 0.21 0.011 0.2 0.02 0.24 0.03914851002 155 6.683 7.079 0.396 1.4 0.92 0.4514851002 156 0.21 0.0099 0.23 0.018 0.19 0.04514851002 157 7.079 7.499 0.419 1.341 0.9 0.4414851002 158 0.21 0.0091 0.2 0.017 0.24 0.05414851002 159 7.499 7.943 0.444 1.321 0.88 0.4514851002 160 0.2 0.009 0.2 0.016 0.21 0.0514851002 161 7.943 8.414 0.471 1.309 0.91 0.4614851002 162 0.21 0.0091 0.22 0.015 0.24 0.05714851002 163 8.414 8.913 0.499 1.302 0.95 0.4714851002 164 0.2 0.0092 0.2 0.015 0.22 0.05214851002 165 8.913 9.441 0.528 1.31 0.92 0.4814851002 166 0.22 0.0096 0.22 0.014 0.22 0.05214851002 167 9.441 10. 0.559 1.3 0.97 0.514851002 168 0.22 0.0099 0.19 0.015 0.23 0.04914851002 169 10. 10.59 0.593 1.322 0.94 0.5214851002 170 0.22 0.01 0.21 0.016 0.21 0.0514851002 171 10.59 11.22 0.628 1.332 0.97 0.5514851002 172 0.2 0.011 0.18 0.018 0.27 0.05214851002 173 11.22 11.89 0.665 1.33 1. 0.5714851002 174 0.23 0.012 0.21 0.022 0.28 0.05414851002 175 11.89 12.59 0.704 1.329 1. 0.5914851002 176 0.25 0.012 0.23 0.026 0.29 0.06814851002 177 12.59 13.34 0.746 1.273 1. 0.5914851002 178 0.25 0.012 0.18 0.027 0.3 0.06414851002 179 13.34 14.13 0.79 1.211 1. 0.614851002 180 0.19 0.012 0.2 0.029 0.29 0.06114851002 181 14.13 14.96 0.837 1.159 1. 0.6114851002 182 0.23 0.012 0.21 0.031 0.31 0.06714851002 183 14.96 15.85 0.887 1.157 1.1 0.6114851002 184 0.21 0.012 0.22 0.031 0.34 0.06114851002 185 15.85 16.79 0.939 1.135 1.1 0.6314851002 186 0.25 0.012 0.2 0.031 0.3 0.06714851002 187 16.79 17.78 0.995 1.146 1.1 0.6514851002 188 0.21 0.012 0.2 0.029 0.34 0.06214851002 189 17.78 18.84 1.05 1.161 1.1 0.6414851002 190 0.24 0.012 0.22 0.023 0.3 0.07414851002 191 18.84 19.95 1.12 1.184 1.1 0.6614851002 192 0.22 0.012 0.18 0.016 0.33 0.08614851002 193 19.95 21.13 1.18 1.17 1.1 0.6814851002 194 0.22 0.012 0.2 0.016 0.29 0.07814851002 195 21.13 22.39 1.25 1.161 1.1 0.6814851002 196 0.25 0.012 0.21 0.016 0.34 0.07514851002 197 22.39 23.71 1.33 1.128 1.1 0.6814851002 198 0.19 0.012 0.17 0.016 0.33 0.08114851002 199 23.71 25.12 1.41 1.117 1.1 0.6814851002 200 0.21 0.011 0.2 0.016 0.36 0.07414851002 201 25.12 26.61 1.49 1.098 1.1 0.6914851002 202 0.21 0.011 0.17 0.014 0.38 0.07914851002 203 26.61 28.18 1.58 1.1 1.1 0.6914851002 204 0.2 0.011 0.23 0.011 0.36 0.07414851002 205 28.18 29.85 1.67 1.076 1.1 0.714851002 206 0.19 0.011 0.2 0.007 0.36 0.07814851002 207 29.85 31.62 1.77 1.105 1.2 0.714851002 208 0.21 0.011 0.2 0.0056 0.36 0.09314851002 209 31.62 33.5 1.87 1.092 1.1 0.714851002 210 0.22 0.011 0.21 0.0056 0.34 0.08714851002 211 33.5 35.48 1.98 1.091 1.1 0.6914851002 212 0.19 0.0098 0.2 0.0056 0.3 0.08714851002 213 35.48 37.58 2.1 1.103 1.1 0.714851002 214 0.3 0.01 0.22 0.0056 0.34 0.08114851002 215 37.58 39.81 2.23 1.097 1.1 0.7114851002 216 0.26 0.0096 0.18 0.0056 0.34 0.08914851002 217 39.81 42.17 2.36 1.105 1.2 0.7214851002 218 0.2 0.0097 0.19 0.0056 0.35 0.0914851002 219 42.17 44.67 2.5 1.092 1.2 0.7314851002 220 0.2 0.0095 0.23 0.0056 0.38 0.0814851002 221 44.67 47.32 2.65 1.092 1.2 0.7314851002 222 0.26 0.0095 0.2 0.0056 0.31 0.08514851002 223 47.32 50.12 2.8 1.075 1.2 0.7514851002 224 0.22 0.0094 0.2 0.0056 0.35 0.1114851002 225 50.12 53.09 2.97 1.078 1.2 0.7714851002 226 0.26 0.0095 0.18 0.0056 0.35 0.114851002 227 53.09 56.23 3.15 1.086 1.1 0.7614851002 228 0.2 0.0094 0.17 0.0056 0.39 0.1114851002 229 56.23 59.57 3.33 1.113 1.1 0.7814851002 230 0.21 0.0092 0.21 0.0056 0.41 0.08814851002 231 59.57 63.1 3.53 1.083 1.2 0.7914851002 232 0.2 0.0093 0.18 0.0056 0.39 0.09514851002 233 63.1 66.83 3.74 1.118 1.2 0.814851002 234 0.24 0.0092 0.22 0.0056 0.38 0.1114851002 235 66.83 70.79 3.96 1.08 1.2 0.8114851002 236 0.24 0.0095 0.2 0.0056 0.39 0.09414851002 237 70.79 74.99 4.19 1.1 1.3 0.8514851002 238 0.23 0.0096 0.21 0.0056 0.37 0.114851002 239 74.99 79.43 4.44 1.11 1.3 0.8714851002 240 0.27 0.0098 0.2 0.0056 0.49 0.09714851002 241 79.43 84.14 4.71 1.115 1.3 0.914851002 242 0.2 0.0097 0.17 0.0056 0.42 0.09414851002 243 84.14 89.13 4.99 1.097 1.4 0.9114851002 244 0.38 0.01 0.2 0.0056 0.42 0.09814851002 245 89.13 94.41 5.28 1.092 1.3 0.9414851002 246 0.24 0.011 0.22 0.0056 0.51 0.09514851002 247 94.41 100. 5.59 1.081 1.4 0.9914851002 248 0.27 0.011 0.18 0.0056 0.45 0.114851002 249 ENDDATA 242 0 14851002 250 ENDSUBENT 249 0 1485100299999 ENDENTRY 2 0 1485199999999