ENTRY 14851 20250523 1485100000001 SUBENT 14851001 20250523 20251001 1485100100001 BIB 14 84 1485100100002 TITLE Remeasurement of the 239Pu(n,f)/235U(n,f) Cross- 1485100100003 Section Ratio with the NIFFTE fission Time Projection 1485100100004 Chamber Using Vapor-deposited Targets 1485100100005 AUTHOR (D.H.Dongwi,L.Snyder,V.Aguilar,N.Androski, 1485100100006 M.Anastasiou,N.S.Bowden,A.Chemey,T.Classen, 1485100100007 J.E.Fuzaro Alencar,U.Greife,M.Haseman,L.D.Isenhower, 1485100100008 J.L.Klay,W.Loveland,M.P.Mendenhall,M.Monterial, 1485100100009 C.Prokop,M.Silveira,T.S.Watson,L.Yao) 1485100100010 REFERENCE (J,NDS,202,30,2025) 1485100100011 #doi:10.1016/j.nds.2025.04.003 1485100100012 REL-REF (O,14721002,L.Snyder+,J,NDS,178,1,2021) Previous result1485100100013 (I,,L.Snyder+,J,NIM/A,1021,165864,2022) NIFTE TPC 1485100100014 characterization. 1485100100015 INSTITUTE (1USALRL,1USAORU,1USACSM,1USALAS) 1485100100016 (1USAUSA) California Polytechnic State University, San 1485100100017 Luis Obispo, CA 93407, United States 1485100100018 (1USAUSA) Abilene Christian University, Abilene, 1485100100019 TX 79699, United States 1485100100020 FACILITY (LINAC,1USALAS) The Los Alamos Neutron Science Center 1485100100021 (LANSCE) Weapons Neutron Science (WNR) facility. 1485100100022 INC-SOURCE (SPALL) 1485100100023 INC-SPECT The LANSCE facility makes use of an 800 MeV proton 1485100100024 accelerator to provide a pulsed white neutron source. 1485100100025 For this experiment LANSCE delivered 100 Hz pulses, 1485100100026 each approximately 625 microsec in length, containing 1485100100027 micro-pulses separated by 1.8 microsec. 1485100100028 DETECTOR (TPC) The fissionTPC is a two-volume MICROMEGAS TPC, 1485100100029 operated using a gas mixture of high-purity argon and 1485100100030 5% isobutane at 550 torr, with actinide targets 1485100100031 mounted onto the central cathode. 1485100100032 SAMPLE Three samples were prepared from a single source by 1485100100033 pipetting a small volume of acid onto the source and 1485100100034 removing it to a separate vial. Sample solutions were 1485100100035 purified using standard methods and analyzed by 1485100100036 MC-ICP-MS. 1485100100037 Sample #1: 1485100100038 (92-U-235,ENR=0.9989375) 1485100100039 (92-U-234,ENR=0.0002891) 1485100100040 (92-U-236,ENR=0.0001586) 1485100100041 (92-U-238,ENR=0.0006149) 1485100100042 (94-PU-239,ENR=0.999356) 1485100100043 (94-PU-240,ENR=0.0004721) 1485100100044 (94-PU-241,ENR=0.0000708) 1485100100045 (94-PU-242,ENR=0.0001007) 1485100100046 Sample #2: 1485100100047 (92-U-235,ENR=0.9989159) 1485100100048 (92-U-234,ENR=0.0002894) 1485100100049 (92-U-236,ENR=0.0001581) 1485100100050 (92-U-238,ENR=0.0006366) 1485100100051 (94-PU-239,ENR=0.9993324) 1485100100052 (94-PU-240,ENR=0.0004816) 1485100100053 (94-PU-241,ENR=0.0000725) 1485100100054 (94-PU-242,ENR=0.0001135) 1485100100055 Sample #3: 1485100100056 (92-U-235,ENR=0.9989276) 1485100100057 (92-U-234,ENR=0.0002895) 1485100100058 (92-U-236,ENR=0.0001586) 1485100100059 (92-U-238,ENR=0.0006243) 1485100100060 (94-PU-239,ENR=0.9993419) 1485100100061 (94-PU-240,ENR=0.0004773) 1485100100062 (94-PU-241,ENR=0.0000705) 1485100100063 (94-PU-242,ENR=0.0001104) 1485100100064 METHOD (TOF) The 90L flight path. Experiments to measure 1485100100065 fission cross-section ratios are typically arranged 1485100100066 so that the two targets share the same beam, to 1485100100067 ensure that the neutron flux term in ratio cancels out.1485100100068 CORRECTION Following corrections were applied 1485100100069 - wraparound correction 1485100100070 - efficiency correction 1485100100071 - contamination correction 1485100100072 - overlap correction 1485100100073 - beam attenuation and scattering correction 1485100100074 ERR-ANALYS (ERR-T) The absolute, total uncertainty is 1 sigma. 1485100100075 (ERR-S) Statistical uncertainty. 1485100100076 (ERR-1) From the variational analysis. 1485100100077 (ERR-2) The wraparound correction. 1485100100078 (ERR-3) The efficiency correction. 1485100100079 (ERR-4) The contamination correction. 1485100100080 (ERR-5) The overlap correction. 1485100100081 (ERR-6) The beam attenuation and scattering correction.1485100100082 (ERR-7) The normalization correction uncertainty is 1485100100083 0.79%. The normalization uncertainty is energy 1485100100084 independent. 1485100100085 HISTORY (20250523C) BP 1485100100086 ENDBIB 84 0 1485100100087 COMMON 1 3 1485100100088 ERR-7 1485100100089 PER-CENT 1485100100090 0.79 1485100100091 ENDCOMMON 3 0 1485100100092 ENDSUBENT 91 0 1485100199999 SUBENT 14851002 20250523 20251001 1485100200001 BIB 2 2 1485100200002 REACTION ((94-PU-239(N,F),,SIG)/(92-U-235(N,F),,SIG)) 1485100200003 STATUS (TABLE,,D.H.Dongwi+,J,NDS,202,30,2025) Table 3-4 1485100200004 ENDBIB 2 0 1485100200005 NOCOMMON 0 0 1485100200006 DATA 12 119 1485100200007 EN-MIN EN-MAX EN-RSL-FW DATA ERR-T ERR-S 1485100200008 ERR-1 ERR-2 ERR-3 ERR-4 ERR-5 ERR-6 1485100200009 MEV MEV MEV NO-DIM PER-CENT PER-CENT 1485100200010 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 1485100200011 0.1059 0.1122 0.00628 0.963 2.9 1.61485100200012 1.5 0.6 0.19 0.099 0.54 0.141485100200013 0.1122 0.1189 0.00665 0.95 2.7 1.61485100200014 1.7 0.54 0.22 0.12 0.58 0.131485100200015 0.1189 0.1259 0.00704 0.9957 2.5 1.41485100200016 1. 0.45 0.21 0.13 0.48 0.141485100200017 0.1259 0.1334 0.00746 0.9815 2.4 1.41485100200018 1.3 0.41 0.23 0.11 0.46 0.121485100200019 0.1334 0.1413 0.0079 1.045 2.1 1.31485100200020 1.1 0.35 0.2 0.082 0.48 0.121485100200021 0.1413 0.1496 0.00837 1.071 2.2 1.31485100200022 0.99 0.35 0.2 0.057 0.53 0.141485100200023 0.1496 0.1585 0.00887 1.098 1.9 1.11485100200024 0.83 0.28 0.2 0.057 0.47 0.121485100200025 0.1585 0.1679 0.00939 1.083 1.8 1.11485100200026 1.2 0.26 0.2 0.064 0.38 0.121485100200027 0.1679 0.1778 0.00995 1.091 1.8 1.11485100200028 1. 0.24 0.22 0.066 0.46 0.111485100200029 0.1778 0.1884 0.0105 1.13 1.6 1.1485100200030 0.82 0.21 0.22 0.06 0.39 0.0981485100200031 0.1884 0.1995 0.0112 1.079 1.7 1.1485100200032 0.82 0.22 0.2 0.053 0.41 0.111485100200033 0.1995 0.2113 0.0118 1.134 1.5 0.931485100200034 0.76 0.18 0.2 0.051 0.37 0.0981485100200035 0.2113 0.2239 0.0125 1.187 1.5 0.911485100200036 0.74 0.17 0.2 0.053 0.38 0.0831485100200037 0.2239 0.2371 0.0133 1.202 1.4 0.861485100200038 0.64 0.16 0.19 0.055 0.34 0.0841485100200039 0.2371 0.2512 0.0141 1.166 1.4 0.841485100200040 0.65 0.15 0.19 0.055 0.33 0.091485100200041 0.2512 0.2661 0.0149 1.198 1.3 0.811485100200042 0.57 0.14 0.2 0.053 0.32 0.0971485100200043 0.2661 0.2818 0.0158 1.263 1.2 0.761485100200044 0.54 0.13 0.21 0.05 0.33 0.0641485100200045 0.2818 0.2985 0.0167 1.272 1.2 0.751485100200046 0.45 0.12 0.19 0.049 0.31 0.071485100200047 0.2985 0.3162 0.0177 1.266 1.2 0.691485100200048 0.45 0.1 0.21 0.049 0.34 0.0741485100200049 0.3162 0.335 0.0187 1.282 1.1 0.691485100200050 0.4 0.1 0.19 0.05 0.31 0.0681485100200051 0.335 0.3548 0.0198 1.293 1.1 0.631485100200052 0.36 0.089 0.23 0.049 0.26 0.0641485100200053 0.3548 0.3758 0.021 1.292 1. 0.631485100200054 0.34 0.082 0.22 0.048 0.28 0.071485100200055 0.3758 0.3981 0.0223 1.306 1. 0.611485100200056 0.34 0.077 0.2 0.047 0.25 0.0881485100200057 0.3981 0.4217 0.0236 1.305 1. 0.591485100200058 0.31 0.074 0.18 0.048 0.25 0.0581485100200059 0.4217 0.4467 0.025 1.363 1. 0.581485100200060 0.32 0.073 0.19 0.048 0.25 0.0621485100200061 0.4467 0.4732 0.0265 1.402 1. 0.551485100200062 0.37 0.067 0.19 0.049 0.26 0.0541485100200063 0.4732 0.5012 0.028 1.407 0.98 0.541485100200064 0.26 0.062 0.2 0.05 0.25 0.0561485100200065 0.5012 0.5309 0.0297 1.416 0.95 0.51485100200066 0.26 0.057 0.2 0.05 0.23 0.0561485100200067 0.5309 0.5623 0.0315 1.422 0.97 0.51485100200068 0.29 0.048 0.21 0.05 0.25 0.0561485100200069 0.5623 0.5957 0.0333 1.42 0.93 0.491485100200070 0.24 0.046 0.23 0.05 0.22 0.0661485100200071 0.5957 0.631 0.0353 1.475 0.91 0.471485100200072 0.21 0.04 0.2 0.05 0.2 0.0521485100200073 0.631 0.6683 0.0374 1.472 0.91 0.451485100200074 0.24 0.042 0.21 0.05 0.23 0.0581485100200075 0.6683 0.7079 0.0396 1.486 0.92 0.451485100200076 0.25 0.042 0.18 0.05 0.19 0.0521485100200077 0.7079 0.7499 0.0419 1.496 0.92 0.441485100200078 0.22 0.037 0.19 0.049 0.2 0.0541485100200079 0.7499 0.7943 0.0444 1.546 0.9 0.431485100200080 0.2 0.037 0.21 0.049 0.21 0.0461485100200081 0.7943 0.8414 0.0471 1.569 0.92 0.421485100200082 0.2 0.033 0.22 0.05 0.2 0.0521485100200083 0.8414 0.8913 0.0499 1.525 0.91 0.411485100200084 0.22 0.03 0.2 0.049 0.22 0.0391485100200085 0.8913 0.9441 0.0528 1.487 0.91 0.411485100200086 0.24 0.027 0.21 0.048 0.18 0.0381485100200087 0.9441 1. 0.0559 1.456 0.86 0.41485100200088 0.22 0.026 0.21 0.046 0.2 0.041485100200089 1. 1.059 0.0593 1.458 0.89 0.41485100200090 0.22 0.024 0.22 0.046 0.2 0.0391485100200091 1.059 1.122 0.0628 1.486 0.89 0.391485100200092 0.24 0.023 0.2 0.046 0.19 0.041485100200093 1.122 1.189 0.0665 1.504 0.86 0.391485100200094 0.21 0.021 0.2 0.046 0.18 0.0461485100200095 1.189 1.259 0.0704 1.54 0.87 0.391485100200096 0.21 0.02 0.19 0.045 0.19 0.0411485100200097 1.259 1.334 0.0746 1.568 0.86 0.381485100200098 0.26 0.022 0.18 0.044 0.19 0.0421485100200099 1.334 1.413 0.079 1.6 0.89 0.381485100200100 0.22 0.021 0.21 0.043 0.23 0.0341485100200101 1.413 1.496 0.0837 1.603 0.88 0.381485100200102 0.22 0.018 0.2 0.042 0.2 0.0421485100200103 1.496 1.585 0.0887 1.594 0.86 0.381485100200104 0.21 0.017 0.19 0.041 0.17 0.0821485100200105 1.585 1.679 0.0939 1.569 0.88 0.381485100200106 0.19 0.018 0.22 0.04 0.19 0.0391485100200107 1.679 1.778 0.0995 1.587 0.83 0.381485100200108 0.28 0.017 0.23 0.039 0.18 0.041485100200109 1.778 1.884 0.105 1.555 0.86 0.381485100200110 0.19 0.017 0.17 0.038 0.18 0.0471485100200111 1.884 1.995 0.112 1.569 0.86 0.381485100200112 0.23 0.017 0.19 0.036 0.18 0.0361485100200113 1.995 2.113 0.118 1.585 0.88 0.371485100200114 0.23 0.015 0.21 0.035 0.17 0.0411485100200115 2.113 2.239 0.125 1.576 0.87 0.381485100200116 0.21 0.014 0.18 0.034 0.18 0.0461485100200117 2.239 2.371 0.133 1.557 0.88 0.381485100200118 0.22 0.013 0.21 0.033 0.19 0.0371485100200119 2.371 2.512 0.141 1.56 0.87 0.391485100200120 0.2 0.015 0.21 0.032 0.19 0.0411485100200121 2.512 2.661 0.149 1.552 0.89 0.391485100200122 0.21 0.014 0.2 0.031 0.19 0.0321485100200123 2.661 2.818 0.158 1.555 0.88 0.391485100200124 0.2 0.013 0.2 0.029 0.22 0.0391485100200125 2.818 2.985 0.167 1.554 0.88 0.41485100200126 0.21 0.014 0.17 0.028 0.2 0.0481485100200127 2.985 3.162 0.177 1.562 0.86 0.41485100200128 0.24 0.013 0.2 0.027 0.17 0.041485100200129 3.162 3.35 0.187 1.565 0.89 0.41485100200130 0.22 0.013 0.21 0.026 0.2 0.041485100200131 3.35 3.548 0.198 1.584 0.9 0.411485100200132 0.22 0.014 0.18 0.025 0.22 0.0381485100200133 3.548 3.758 0.21 1.607 0.91 0.421485100200134 0.17 0.014 0.2 0.023 0.22 0.0461485100200135 3.758 3.981 0.223 1.576 0.89 0.411485100200136 0.23 0.013 0.19 0.022 0.21 0.0421485100200137 3.981 4.217 0.236 1.581 0.89 0.431485100200138 0.23 0.012 0.19 0.021 0.21 0.0421485100200139 4.217 4.467 0.25 1.59 0.91 0.441485100200140 0.2 0.012 0.2 0.02 0.16 0.041485100200141 4.467 4.732 0.265 1.601 0.91 0.451485100200142 0.24 0.013 0.2 0.02 0.22 0.0371485100200143 4.732 5.012 0.28 1.607 0.9 0.461485100200144 0.18 0.013 0.18 0.02 0.22 0.0361485100200145 5.012 5.309 0.297 1.598 0.92 0.471485100200146 0.19 0.014 0.19 0.021 0.2 0.041485100200147 5.309 5.623 0.315 1.657 0.92 0.481485100200148 0.21 0.013 0.18 0.022 0.21 0.0361485100200149 5.623 5.957 0.333 1.653 0.94 0.491485100200150 0.23 0.013 0.16 0.023 0.22 0.0371485100200151 5.957 6.31 0.353 1.592 0.95 0.481485100200152 0.2 0.012 0.19 0.022 0.22 0.0411485100200153 6.31 6.683 0.374 1.503 0.88 0.461485100200154 0.21 0.011 0.2 0.02 0.24 0.0391485100200155 6.683 7.079 0.396 1.4 0.92 0.451485100200156 0.21 0.0099 0.23 0.018 0.19 0.0451485100200157 7.079 7.499 0.419 1.341 0.9 0.441485100200158 0.21 0.0091 0.2 0.017 0.24 0.0541485100200159 7.499 7.943 0.444 1.321 0.88 0.451485100200160 0.2 0.009 0.2 0.016 0.21 0.051485100200161 7.943 8.414 0.471 1.309 0.91 0.461485100200162 0.21 0.0091 0.22 0.015 0.24 0.0571485100200163 8.414 8.913 0.499 1.302 0.95 0.471485100200164 0.2 0.0092 0.2 0.015 0.22 0.0521485100200165 8.913 9.441 0.528 1.31 0.92 0.481485100200166 0.22 0.0096 0.22 0.014 0.22 0.0521485100200167 9.441 10. 0.559 1.3 0.97 0.51485100200168 0.22 0.0099 0.19 0.015 0.23 0.0491485100200169 10. 10.59 0.593 1.322 0.94 0.521485100200170 0.22 0.01 0.21 0.016 0.21 0.051485100200171 10.59 11.22 0.628 1.332 0.97 0.551485100200172 0.2 0.011 0.18 0.018 0.27 0.0521485100200173 11.22 11.89 0.665 1.33 1. 0.571485100200174 0.23 0.012 0.21 0.022 0.28 0.0541485100200175 11.89 12.59 0.704 1.329 1. 0.591485100200176 0.25 0.012 0.23 0.026 0.29 0.0681485100200177 12.59 13.34 0.746 1.273 1. 0.591485100200178 0.25 0.012 0.18 0.027 0.3 0.0641485100200179 13.34 14.13 0.79 1.211 1. 0.61485100200180 0.19 0.012 0.2 0.029 0.29 0.0611485100200181 14.13 14.96 0.837 1.159 1. 0.611485100200182 0.23 0.012 0.21 0.031 0.31 0.0671485100200183 14.96 15.85 0.887 1.157 1.1 0.611485100200184 0.21 0.012 0.22 0.031 0.34 0.0611485100200185 15.85 16.79 0.939 1.135 1.1 0.631485100200186 0.25 0.012 0.2 0.031 0.3 0.0671485100200187 16.79 17.78 0.995 1.146 1.1 0.651485100200188 0.21 0.012 0.2 0.029 0.34 0.0621485100200189 17.78 18.84 1.05 1.161 1.1 0.641485100200190 0.24 0.012 0.22 0.023 0.3 0.0741485100200191 18.84 19.95 1.12 1.184 1.1 0.661485100200192 0.22 0.012 0.18 0.016 0.33 0.0861485100200193 19.95 21.13 1.18 1.17 1.1 0.681485100200194 0.22 0.012 0.2 0.016 0.29 0.0781485100200195 21.13 22.39 1.25 1.161 1.1 0.681485100200196 0.25 0.012 0.21 0.016 0.34 0.0751485100200197 22.39 23.71 1.33 1.128 1.1 0.681485100200198 0.19 0.012 0.17 0.016 0.33 0.0811485100200199 23.71 25.12 1.41 1.117 1.1 0.681485100200200 0.21 0.011 0.2 0.016 0.36 0.0741485100200201 25.12 26.61 1.49 1.098 1.1 0.691485100200202 0.21 0.011 0.17 0.014 0.38 0.0791485100200203 26.61 28.18 1.58 1.1 1.1 0.691485100200204 0.2 0.011 0.23 0.011 0.36 0.0741485100200205 28.18 29.85 1.67 1.076 1.1 0.71485100200206 0.19 0.011 0.2 0.007 0.36 0.0781485100200207 29.85 31.62 1.77 1.105 1.2 0.71485100200208 0.21 0.011 0.2 0.0056 0.36 0.0931485100200209 31.62 33.5 1.87 1.092 1.1 0.71485100200210 0.22 0.011 0.21 0.0056 0.34 0.0871485100200211 33.5 35.48 1.98 1.091 1.1 0.691485100200212 0.19 0.0098 0.2 0.0056 0.3 0.0871485100200213 35.48 37.58 2.1 1.103 1.1 0.71485100200214 0.3 0.01 0.22 0.0056 0.34 0.0811485100200215 37.58 39.81 2.23 1.097 1.1 0.711485100200216 0.26 0.0096 0.18 0.0056 0.34 0.0891485100200217 39.81 42.17 2.36 1.105 1.2 0.721485100200218 0.2 0.0097 0.19 0.0056 0.35 0.091485100200219 42.17 44.67 2.5 1.092 1.2 0.731485100200220 0.2 0.0095 0.23 0.0056 0.38 0.081485100200221 44.67 47.32 2.65 1.092 1.2 0.731485100200222 0.26 0.0095 0.2 0.0056 0.31 0.0851485100200223 47.32 50.12 2.8 1.075 1.2 0.751485100200224 0.22 0.0094 0.2 0.0056 0.35 0.111485100200225 50.12 53.09 2.97 1.078 1.2 0.771485100200226 0.26 0.0095 0.18 0.0056 0.35 0.11485100200227 53.09 56.23 3.15 1.086 1.1 0.761485100200228 0.2 0.0094 0.17 0.0056 0.39 0.111485100200229 56.23 59.57 3.33 1.113 1.1 0.781485100200230 0.21 0.0092 0.21 0.0056 0.41 0.0881485100200231 59.57 63.1 3.53 1.083 1.2 0.791485100200232 0.2 0.0093 0.18 0.0056 0.39 0.0951485100200233 63.1 66.83 3.74 1.118 1.2 0.81485100200234 0.24 0.0092 0.22 0.0056 0.38 0.111485100200235 66.83 70.79 3.96 1.08 1.2 0.811485100200236 0.24 0.0095 0.2 0.0056 0.39 0.0941485100200237 70.79 74.99 4.19 1.1 1.3 0.851485100200238 0.23 0.0096 0.21 0.0056 0.37 0.11485100200239 74.99 79.43 4.44 1.11 1.3 0.871485100200240 0.27 0.0098 0.2 0.0056 0.49 0.0971485100200241 79.43 84.14 4.71 1.115 1.3 0.91485100200242 0.2 0.0097 0.17 0.0056 0.42 0.0941485100200243 84.14 89.13 4.99 1.097 1.4 0.911485100200244 0.38 0.01 0.2 0.0056 0.42 0.0981485100200245 89.13 94.41 5.28 1.092 1.3 0.941485100200246 0.24 0.011 0.22 0.0056 0.51 0.0951485100200247 94.41 100. 5.59 1.081 1.4 0.991485100200248 0.27 0.011 0.18 0.0056 0.45 0.11485100200249 ENDDATA 242 0 1485100200250 ENDSUBENT 249 0 1485100299999 ENDENTRY 2 0 1485199999999