ENTRY 31692 20100520 31692 0 1 SUBENT 31692001 20100520 31692 1 1 BIB 14 70 31692 1 2 TITLE The 235U(n,f) Prompt Fission Neutron Spectrum at 100 K 31692 1 3 Input Neutron Energy 31692 1 4 AUTHOR (N.Kornilov,F.-J.Hambsch,I.Fabry,S.Oberstedt,T.Belgya, 31692 1 5 Z.Kis,L.Szentmiklosi,S.Simakov) 31692 1 6 INSTITUTE (1USAOHO) N.Kornilov 31692 1 7 (2ZZZGEL)F.-J.Hambsch,I.Fabry,S.Oberstedt 31692 1 8 (3HUNII)T.Belgya,Z.Kis,L.Szentmiklosi 31692 1 9 (2GERKFK)S.Simakov 31692 1 10 REFERENCE (J,NSE,165,117,2010) 31692 1 11 FACILITY (REAC,3HUNII)cold-neutron prompt gamma activation 31692 1 12 analysis facility of the Budapest Nuclear Research 31692 1 13 Reactor 31692 1 14 SAMPLE 235UF4 (97.7% enrichment in 235U, 30 mm (diam.) layer 31692 1 15 of 112 mu-g/cm2 thickness evaporated onto 31692 1 16 a gold-coated(40 mu-g/cm2)thin (24 mu-g/cm2) polyimide 31692 1 17 foil 31692 1 18 A 252Cf layer(10 mm (diam.) was placed in the same 31692 1 19 chamber but shifted by 5 cm from the U layer and 31692 1 20 out of the neutron beam. 31692 1 21 DETECTOR (SCIN) Three identical neutron detectors, 31692 1 22 organic NE213-equivalent scintillator LS301(101.6 mm, 31692 1 23 h=50.8 mm) coupled to XP4312 photomultiplier tubes. 31692 1 24 Detectors were placed at different angles relative to31692 1 25 the neutron beam, and at slightly different flight 31692 1 26 paths L (Det 1, angle1 = 72 deg, L1 = 298.1 cm, 31692 1 27 Det 2, angle2 = 102 deg, L2 = 282.8 cm, Det 3, 31692 1 28 angle3= 132 deg, L3 = 301.1 cm). 31692 1 29 (FISCH) The fission ionization chamber was made of 31692 1 30 stainless steel(diameter D=180 mm, height H=145 mm, 31692 1 31 wall thickness=0.5 mm). Counting efficiency 98%. 31692 1 32 METHOD (TOF) time-of-flight method. 31692 1 33 Time resolution FWHM = 1.7 ns for U and 2.1 ns for Cf 31692 1 34 Time channel width was measured with accuracy <0.1% 31692 1 35 to 0.1178 ns and 0.1150 ns for U and Cf channels. 31692 1 36 The gamma-ray suppression factor was about 200. 31692 1 37 Time-independent and time-correlated background was 31692 1 38 subtracted. 31692 1 39 INC-SOURCE (REAC)cold-neutron at 100 K incident neutron energy 31692 1 40 The neutron flux was ~5E+07 1/cm2/s and the actual beam31692 1 41 dimension at the measuring station was ~2x2.5 cm2. 31692 1 42 CORRECTION The correction factors for multiple scattering and 331692 1 43 attenuation were calculated with the MCNP code as a 31692 1 44 ratio of a neutron spectrum emitted from the source 31692 1 45 surrounded by the real chamber to a spectrum calculated31692 1 46 without chamber materials. The neutron spectra were 31692 1 47 calculated separately for the U and Cf sources. 31692 1 48 The ratio of the correction factors of Cf to U was 31692 1 49 determined. The experimental data were multiplied 31692 1 50 by these functions to cancel the contribution of the 31692 1 51 scattered neutrons on the fission chamber materials. 31692 1 52 ANALYSIS The experimental prompt fission neutron spectrum was 31692 1 53 normalized to unity, and the average secondary neutron 31692 1 54 energy was calculated. A Maxwellian spectrum was fitted31692 1 55 in the energy range of 0.7 to 1.5 MeV and 9 to 11MeV to31692 1 56 the measured spectrum, and an extrapolation to zero and31692 1 57 to 20 MeV was performed. 31692 1 58 ERR-ANALYS (ERR-T) The total uncertainties were estimated from the31692 1 59 following partial uncertainties: 31692 1 60 (ERR-S) The statistical error for one detector 31692 1 61 (ERR-1) The uncertainty of the Cf standard, 31692 1 62 (ERR-2) Systematic uncertainties due to shift of the 31692 1 63 zero time (+-2channels) 31692 1 64 (ERR-3) Systematic uncertainties due to shift of the 31692 1 65 flight path 0.5 cm 31692 1 66 (ERR-4) Systematic uncertainties due to shift of the 31692 1 67 channel width 0.1%. 31692 1 68 HISTORY (20100520C) VS 31692 1 69 STATUS (TABLE) Data from Table 3 and text of the ref. 31692 1 70 NSE,165,117,2010 31692 1 71 (APRVD) Entry was approved by N.Kornilov 31692 1 72 ENDBIB 70 0 31692 1 73 COMMON 1 3 31692 1 74 KT-K 31692 1 75 K 31692 1 76 100. 31692 1 77 ENDCOMMON 3 0 31692 1 78 ENDSUBENT 77 0 31692 199999 SUBENT 31692002 20100520 31692 2 1 BIB 1 2 31692 2 2 REACTION (92-U-235(N,F),PR,NU/DE,,NPD) Average spectrum based 31692 2 3 on the three detector spectra 31692 2 4 ENDBIB 2 0 31692 2 5 NOCOMMON 0 0 31692 2 6 DATA 8 112 31692 2 7 E DATA ERR-T ERR-S ERR-1 ERR-2 31692 2 8 ERR-3 ERR-4 31692 2 9 MEV 1/MEV PER-CENT PER-CENT PER-CENT PER-CENT 31692 2 10 PER-CENT PER-CENT 31692 2 11 0.73.57417E-01 1.8 0.5 1.7 0.031692 2 12 0.0 0. 31692 2 13 0.83.56987E-01 1.7 0.3 1.7 0.031692 2 14 0.0 0. 31692 2 15 0.93.53764E-01 1.6 0.3 1.6 0.031692 2 16 0.0 0. 31692 2 17 1.03.46116E-01 1.5 0.3 1.5 0.031692 2 18 0.1 0. 31692 2 19 1.13.35848E-01 1.2 0.3 1.2 0.131692 2 20 0.1 0.1 31692 2 21 1.23.30266E-01 1.2 0.3 1.2 0.131692 2 22 0.1 0.1 31692 2 23 1.33.17927E-01 1.2 0.3 1.2 0.131692 2 24 0.1 0.1 31692 2 25 1.43.05490E-01 1.3 0.3 1.2 0.131692 2 26 0.2 0.1 31692 2 27 1.52.95665E-01 1.3 0.3 1.2 0.131692 2 28 0.2 0.1 31692 2 29 1.62.85520E-01 1.3 0.3 1.2 0.231692 2 30 0.2 0.1 31692 2 31 1.72.73825E-01 1.3 0.3 1.2 0.231692 2 32 0.2 0.1 31692 2 33 1.82.60643E-01 1.3 0.3 1.2 0.231692 2 34 0.2 0.1 31692 2 35 1.92.49482E-01 1.3 0.3 1.2 0.231692 2 36 0.3 0.2 31692 2 37 2.02.38831E-01 1.3 0.4 1.2 0.231692 2 38 0.3 0.2 31692 2 39 2.12.26406E-01 1.3 0.4 1.2 0.331692 2 40 0.3 0.2 31692 2 41 2.22.15138E-01 1.3 0.4 1.2 0.331692 2 42 0.3 0.2 31692 2 43 2.32.03569E-01 1.3 0.4 1.2 0.331692 2 44 0.3 0.2 31692 2 45 2.41.94639E-01 1.4 0.4 1.2 0.331692 2 46 0.4 0.2 31692 2 47 2.51.84269E-01 1.4 0.4 1.2 0.431692 2 48 0.4 0.2 31692 2 49 2.61.73786E-01 1.4 0.4 1.2 0.431692 2 50 0.4 0.3 31692 2 51 2.71.63929E-01 1.4 0.5 1.2 0.431692 2 52 0.4 0.3 31692 2 53 2.81.56018E-01 1.5 0.5 1.2 0.531692 2 54 0.5 0.3 31692 2 55 2.91.44610E-01 1.5 0.5 1.2 0.531692 2 56 0.5 0.3 31692 2 57 3.01.38017E-01 1.5 0.5 1.2 0.531692 2 58 0.5 0.3 31692 2 59 3.11.32063E-01 1.5 0.5 1.2 0.531692 2 60 0.5 0.3 31692 2 61 3.21.22600E-01 1.6 0.6 1.2 0.631692 2 62 0.5 0.3 31692 2 63 3.31.15102E-01 1.6 0.6 1.2 0.631692 2 64 0.6 0.3 31692 2 65 3.41.08014E-01 1.6 0.6 1.2 0.631692 2 66 0.6 0.3 31692 2 67 3.51.02317E-01 1.7 0.7 1.2 0.731692 2 68 0.6 0.4 31692 2 69 3.69.53697E-02 1.7 0.7 1.2 0.731692 2 70 0.6 0.4 31692 2 71 3.78.97708E-02 1.8 0.7 1.2 0.831692 2 72 0.6 0.4 31692 2 73 3.88.37001E-02 1.8 0.7 1.2 0.831692 2 74 0.7 0.4 31692 2 75 3.97.76392E-02 1.8 0.8 1.2 0.831692 2 76 0.7 0.4 31692 2 77 4.07.30070E-02 1.9 0.8 1.2 0.931692 2 78 0.7 0.4 31692 2 79 4.16.90418E-02 2.0 0.9 1.3 0.931692 2 80 0.7 0.4 31692 2 81 4.26.50629E-02 2.1 1.0 1.3 0.931692 2 82 0.7 0.5 31692 2 83 4.35.98605E-02 2.2 1.1 1.3 1.031692 2 84 0.8 0.5 31692 2 85 4.45.67961E-02 2.2 1.1 1.3 1.031692 2 86 0.8 0.5 31692 2 87 4.55.34921E-02 2.4 1.2 1.4 1.131692 2 88 0.9 0.5 31692 2 89 4.64.98350E-02 2.3 1.0 1.4 1.131692 2 90 0.9 0.5 31692 2 91 4.74.63185E-02 2.4 1.2 1.4 1.131692 2 92 0.9 0.5 31692 2 93 4.84.33314E-02 2.5 1.3 1.4 1.231692 2 94 0.9 0.5 31692 2 95 4.94.02959E-02 2.5 1.3 1.4 1.231692 2 96 0.9 0.5 31692 2 97 5.03.69947E-02 2.4 1.2 1.4 1.231692 2 98 0.9 0.5 31692 2 99 5.13.40869E-02 2.5 1.0 1.5 1.331692 2 100 1.0 0.6 31692 2 101 5.23.22506E-02 2.6 1.0 1.5 1.431692 2 102 1.0 0.6 31692 2 103 5.32.98670E-02 2.6 1.1 1.5 1.431692 2 104 1.0 0.6 31692 2 105 5.42.74606E-02 2.6 1.1 1.5 1.431692 2 106 1.0 0.6 31692 2 107 5.52.62360E-02 2.7 1.2 1.5 1.531692 2 108 1.0 0.6 31692 2 109 5.62.41894E-02 2.7 1.2 1.5 1.531692 2 110 1.0 0.6 31692 2 111 5.72.30378E-02 2.8 1.2 1.5 1.631692 2 112 1.1 0.6 31692 2 113 5.82.15183E-02 2.8 1.3 1.5 1.631692 2 114 1.1 0.6 31692 2 115 5.92.02001E-02 3.0 1.3 1.6 1.731692 2 116 1.1 0.6 31692 2 117 6.01.83687E-02 3.0 1.4 1.6 1.731692 2 118 1.1 0.7 31692 2 119 6.11.70343E-02 3.1 1.5 1.6 1.831692 2 120 1.1 0.7 31692 2 121 6.21.59145E-02 3.2 1.5 1.6 1.831692 2 122 1.2 0.7 31692 2 123 6.31.49535E-02 3.3 1.6 1.6 1.931692 2 124 1.2 0.7 31692 2 125 6.41.38986E-02 3.3 1.7 1.6 1.931692 2 126 1.2 0.7 31692 2 127 6.51.30345E-02 3.4 1.7 1.6 2.031692 2 128 1.2 0.7 31692 2 129 6.61.19165E-02 3.5 1.8 1.7 2.031692 2 130 1.2 0.8 31692 2 131 6.71.13091E-02 3.6 1.9 1.7 2.131692 2 132 1.3 0.7 31692 2 133 6.81.07435E-02 3.7 2.0 1.7 2.131692 2 134 1.3 0.8 31692 2 135 6.99.72144E-03 3.8 2.1 1.8 2.231692 2 136 1.3 0.8 31692 2 137 7.08.91950E-03 3.9 2.2 1.8 2.231692 2 138 1.3 0.8 31692 2 139 7.18.48056E-03 4.0 2.2 1.8 2.331692 2 140 1.3 0.8 31692 2 141 7.27.98577E-03 4.1 2.3 1.8 2.331692 2 142 1.4 0.8 31692 2 143 7.37.25898E-03 4.2 2.5 1.8 2.431692 2 144 1.4 0.9 31692 2 145 7.46.71013E-03 4.3 2.6 1.8 2.431692 2 146 1.4 0.8 31692 2 147 7.55.98286E-03 4.4 2.7 1.8 2.531692 2 148 1.4 0.9 31692 2 149 7.65.91121E-03 4.5 2.8 1.9 2.531692 2 150 1.4 0.9 31692 2 151 7.75.45201E-03 4.7 2.9 1.9 2.631692 2 152 1.5 0.9 31692 2 153 7.85.09092E-03 4.8 3.0 1.9 2.631692 2 154 1.5 0.9 31692 2 155 7.94.57645E-03 4.9 3.2 1.9 2.731692 2 156 1.5 0.9 31692 2 157 8.04.35975E-03 5.1 3.3 2.1 2.731692 2 158 1.5 0.9 31692 2 159 8.14.23643E-03 5.2 3.4 2.1 2.831692 2 160 1.5 1. 31692 2 161 8.23.66813E-03 5.5 3.7 2.1 2.931692 2 162 1.6 0.9 31692 2 163 8.33.64082E-03 5.5 3.7 2.1 2.931692 2 164 1.6 1. 31692 2 165 8.43.22232E-03 5.7 4.0 2.1 3.031692 2 166 1.6 0.9 31692 2 167 8.52.93253E-03 6.0 4.3 2.2 3.031692 2 168 1.6 1. 31692 2 169 8.62.84038E-03 6.1 4.3 2.2 3.131692 2 170 1.6 1. 31692 2 171 8.72.62969E-03 6.3 4.6 2.2 3.231692 2 172 1.7 0.9 31692 2 173 8.82.42219E-03 6.5 4.8 2.2 3.231692 2 174 1.7 1. 31692 2 175 8.92.21048E-03 6.8 5.1 2.2 3.331692 2 176 1.7 1. 31692 2 177 9.01.95535E-03 7.1 5.5 2.2 3.331692 2 178 1.7 1. 31692 2 179 9.12.02409E-03 7.1 5.4 2.3 3.431692 2 180 1.7 1. 31692 2 181 9.21.74792E-03 7.6 6.0 2.3 3.531692 2 182 1.8 1.1 31692 2 183 9.31.84417E-03 7.4 5.9 2.3 3.531692 2 184 1.8 1.1 31692 2 185 9.41.67714E-03 7.8 6.1 2.5 3.631692 2 186 1.8 1. 31692 2 187 9.51.50190E-03 8.2 6.6 2.5 3.631692 2 188 1.8 1. 31692 2 189 9.61.42822E-03 8.5 6.9 2.5 3.731692 2 190 1.8 1.1 31692 2 191 9.71.34260E-03 8.8 7.2 2.6 3.831692 2 192 1.9 1.1 31692 2 193 9.81.16071E-03 9.5 8.0 2.6 3.831692 2 194 1.9 1.2 31692 2 195 9.99.64510E-04 10.5 9.1 2.6 3.931692 2 196 1.9 1.1 31692 2 197 10.09.57887E-04 10.5 9.1 2.7 3.931692 2 198 1.9 1.2 31692 2 199 10.18.92867E-04 11.0 9.7 2.7 4.031692 2 200 1.9 1.1 31692 2 201 10.28.55777E-04 11.4 10.0 2.7 4.131692 2 202 2.0 1.2 31692 2 203 10.39.72308E-04 12.0 10.7 2.8 4.131692 2 204 2.0 1.2 31692 2 205 10.47.31997E-04 12.6 11.3 2.8 4.231692 2 206 2.0 1.2 31692 2 207 10.56.36731E-04 13.7 12.5 2.8 4.331692 2 208 2.0 1.1 31692 2 209 10.67.05891E-04 14.0 12.9 2.9 4.331692 2 210 2.0 1.2 31692 2 211 10.75.90681E-04 14.6 13.4 2.9 4.431692 2 212 2.0 1.2 31692 2 213 10.84.62798E-04 16.0 14.9 2.9 4.531692 2 214 2.1 1.2 31692 2 215 10.95.37325E-04 16.6 15.5 2.9 4.531692 2 216 2.1 1.3 31692 2 217 11.05.90958E-04 17.0 15.9 2.9 4.631692 2 218 2.1 1.3 31692 2 219 11.15.09110E-04 17.2 16.1 3.0 4.731692 2 220 2.1 1.3 31692 2 221 11.25.35378E-04 17.3 16.2 3.1 4.731692 2 222 2.1 1.3 31692 2 223 11.34.71756E-04 17.5 16.3 3.2 4.831692 2 224 2.2 1.4 31692 2 225 11.43.32743E-04 20.0 18.9 3.4 4.931692 2 226 2.2 1.4 31692 2 227 11.55.35104E-04 20.0 19.0 3.5 5.031692 2 228 2.2 1.4 31692 2 229 11.63.44137E-04 23.0 22.0 3.5 5.031692 2 230 2.3 1.5 31692 2 231 11.73.87190E-04 23.0 22.0 3.5 5.131692 2 232 2.3 1.5 31692 2 233 11.83.11606E-04 25.0 24.0 3.6 5.231692 2 234 2.3 1.5 31692 2 235 ENDDATA 228 0 31692 2 236 ENDSUBENT 235 0 31692 299999 SUBENT 31692003 20100520 31692 3 1 BIB 1 3 31692 3 2 REACTION (92-U-235(N,F)0-NN-1,PR,KE) Average energy of prompt 31692 3 3 fission neutron average spectrum of the three 31692 3 4 detectors 31692 3 5 ENDBIB 3 0 31692 3 6 NOCOMMON 0 0 31692 3 7 DATA 2 1 31692 3 8 DATA ERR-T 31692 3 9 MEV MEV 31692 3 10 1.988 0.010 31692 3 11 ENDDATA 3 0 31692 3 12 ENDSUBENT 11 0 31692 399999 SUBENT 31692004 20100520 31692 4 1 BIB 1 2 31692 4 2 REACTION (92-U-235(N,F),PR,NU)average neutron multiplicity 31692 4 3 for all detectors 31692 4 4 ENDBIB 2 0 31692 4 5 NOCOMMON 0 0 31692 4 6 DATA 2 1 31692 4 7 DATA DATA-ERR 31692 4 8 PRT/FIS PRT/FIS 31692 4 9 2.47 0.08 31692 4 10 ENDDATA 3 0 31692 4 11 ENDSUBENT 10 0 31692 499999 ENDENTRY 4 0 3169299999999