ENTRY 21546 20230207 231321546 0 1 SUBENT 21546001 20230207 231321546 1 1 BIB 13 57 21546 1 2 TITLE Measurement of the fission neutron energy spectra 21546 1 3 for the fast neutron-induced fission of U-235 and 21546 1 4 U-238 21546 1 5 AUTHOR (A.Bertin,R.Bois,J.Frehaut) 21546 1 6 REFERENCE ((R,INDC(FR)-27,1978)=(R,CEA-R-4913,1978)) in French 21546 1 7 (J,ANS,32,732,1979) 21546 1 8 (P,CEA-N-1875,71,1976) in French 21546 1 9 (J,ANS,22,667,1975) 21546 1 10 (C,75KIEV,5,349,1975) 21546 1 11 INSTITUTE (2FR BRC) 21546 1 12 FACILITY (VDG,2FR BRC) 4 MeV, 1 ns puls-width, 1 MHz repetition 21546 1 13 rate, 3 to 4 uA average current. 21546 1 14 INC-SOURCE (P-LI7) Solid target of 430 ug/cm2, proton 21546 1 15 energy 2.35 MeV for production of 600 keV neutrons. 21546 1 16 (D-D) Deuteron-deuterium reaction on gaseous 21546 1 17 target, 1 cm long, at 2. atm. pressure, deuteron 21546 1 18 energy 4 MeV, entrance window of Havar of 2 microns 21546 1 19 thickness for the production of 7 MeV neutrons. The 21546 1 20 energy loss in the target is 34 keV. 21546 1 21 SAMPLE Massif U hollow cylinder, 2 cm outer diam, 1 cm inner 21546 1 22 diam, 3 cm high, 93.5% enriched in U-235 for the 21546 1 23 sample method. 100 disks of stainless steel, 80 mm 21546 1 24 diam, 0.2 mm thick at distances of 1 mm, with 1 mg/cm2 21546 1 25 fissile material, in the fission chamber method. 21546 1 26 METHOD (TOF) Time-of-flight to detect the fission neutron 21546 1 27 energy. Two methods of measurement were used. The 21546 1 28 sample method (2 m flight path, 600 keV neutrons) 21546 1 29 uses a massif sample. The fission chamber method uses 21546 1 30 thin deposits (1.4 m flight path, 600 keV and 2 m 21546 1 31 flight path, 7 MeV). In this method the incoming 21546 1 32 neutron energy is also measured by TOF. 21546 1 33 DETECTOR (SCIN ) Liquid scintillator NE213, diam=10 cm, 21546 1 34 thickness 5 cm, coupled to a fast photomultiplier (PM)21546 1 35 XP1041 at an angle of 90 degr. With respect to the 21546 1 36 neutron beam, at 2 m from the sample. Its efficiency 21546 1 37 was determined in 3 ways. 21546 1 38 (SCIN) For neutron flux measurements, liquid 21546 1 39 scintillator, NE102, 1 in * 1 in, PM-tube 56AVP. 21546 1 40 (FISCH) Fission chamber filled with 80% argon, 21546 1 41 20% methane, under 4 kJ pressure. 21546 1 42 COMMENT The fission neutron spectrum does not have a 21546 1 43 Maxwellian shape, due to an excess in the low 21546 1 44 energy part of the spectrum. The two methods of 21546 1 45 measurement are compared in table 3 of the 21546 1 46 publication. Also different energy intervals 21546 1 47 are considered to determine the average neutron 21546 1 48 energy. 21546 1 49 CORRECTION Off time slow neutron-induced fission background 21546 1 50 (by a delayed random coincidence method) and 21546 1 51 secondary effects. 21546 1 52 ERR-ANALYS (DATA-ERR) Statistical + systematic (efficiency) 21546 1 53 errors. 21546 1 54 HISTORY (19800514C) G.C. 21546 1 55 (20201016A) SD:Updated to new date formats,lower case. 21546 1 56 Corrections in all Subents. Page of ref.ANS,32, 21546 1 57 corrected (p.733 ->732). 21546 1 58 (20230207A) SD: Subents 003, 004 were added. 21546 1 59 ENDBIB 57 0 21546 1 60 NOCOMMON 0 0 21546 1 61 ENDSUBENT 60 0 21546 199999 SUBENT 21546002 20201016 229421546 2 1 BIB 4 5 21546 2 2 REACTION (92-U-235(N,F)0-NN-1,PR,KE) 21546 2 3 SAMPLE (92-U-235,ENR=0.935) 21546 2 4 STATUS (TABLE) text on p.26 of CEA-R-4913. 21546 2 5 HISTORY (20201016A) SD: SF4=NN-1 added; SF6=AKE -> KE; SF7=N 21546 2 6 deleted from REACTION code. STATUS updated. 21546 2 7 ENDBIB 5 0 21546 2 8 COMMON 1 3 21546 2 9 DATA-ERR 21546 2 10 MEV 21546 2 11 0.006 21546 2 12 ENDCOMMON 3 0 21546 2 13 DATA 3 2 21546 2 14 EN EN-ERR DATA 21546 2 15 MEV MEV MEV 21546 2 16 0.600 0.05 2.04 21546 2 17 7. 0.035 2.14 21546 2 18 ENDDATA 4 0 21546 2 19 ENDSUBENT 18 0 21546 299999 SUBENT 21546003 20201016 229421546 3 1 BIB 3 4 21546 3 2 REACTION (92-U-238(N,F)0-NN-1,PR,KE) 21546 3 3 STATUS (TABLE) text on p.26 of CEA-R-4913. 21546 3 4 HISTORY (20201016A) SD: SF4=NN-1 added; SF6=AKE -> KE; SF7=N 21546 3 5 deleted from REACTION code. STATUS updated. 21546 3 6 ENDBIB 4 0 21546 3 7 NOCOMMON 0 0 21546 3 8 DATA 4 1 21546 3 9 EN EN-ERR DATA DATA-ERR 21546 3 10 MEV MEV MEV MEV 21546 3 11 7. 0.035 2.07 0.07 21546 3 12 ENDDATA 3 0 21546 3 13 ENDSUBENT 12 0 21546 399999 SUBENT 21546004 20230207 231321546 4 1 BIB 4 6 21546 4 2 REACTION (92-U-235(N,F)0-NN-1,PR,NU/DE,,RRE/REL) 21546 4 3 N(E)/sqrt(E) 21546 4 4 SAMPLE (92-U-235,ENR=0.935) 21546 4 5 STATUS (CURVE) Fig.14 of CEA-R-4913 (same on fig.1 of 21546 4 6 Trans.Am.Nuc.Soc.,32,732,1979, only for E=7MeV). 21546 4 7 HISTORY (20230207C) SD 21546 4 8 ENDBIB 6 0 21546 4 9 COMMON 2 3 21546 4 10 E-ERR-DIG ERR-DIG 21546 4 11 MEV PER-CENT 21546 4 12 0.016 1.5 21546 4 13 ENDCOMMON 3 0 21546 4 14 DATA 4 53 21546 4 15 EN E DATA DATA-ERR 21546 4 16 MEV MEV ARB-UNITS ARB-UNITS 21546 4 17 0.6 0.354 3.650E+04 4.747E+03 21546 4 18 0.6 0.398 3.804E+04 3.240E+03 21546 4 19 0.6 0.510 3.302E+04 2.804E+03 21546 4 20 0.6 0.624 2.752E+04 1.735E+03 21546 4 21 0.6 0.804 2.160E+04 1.361E+03 21546 4 22 0.6 0.962 1.876E+04 2.012E+03 21546 4 23 0.6 1.119 1.564E+04 1.328E+03 21546 4 24 0.6 1.298 1.474E+04 1.252E+03 21546 4 25 0.6 1.545 1.181E+04 1.003E+03 21546 4 26 0.6 1.836 9.471E+03 8.042E+02 21546 4 27 0.6 2.262 7.009E+03 4.418E+02 21546 4 28 0.6 2.845 4.415E+03 2.771E+02 21546 4 29 0.6 3.675 2.274E+03 1.427E+02 21546 4 30 0.6 4.952 9.600E+02 8.177E+01 21546 4 31 0.6 7.389 2.368E+02 2.539E+01 21546 4 32 0.6 9.791 2.919E+01 7.334E+00 21546 4 33 7.0 0.391 1.856E+05 3.424E+04 21546 4 34 7.0 0.479 1.858E+05 1.882E+04 21546 4 35 7.0 0.523 1.814E+05 1.843E+04 21546 4 36 7.0 0.589 1.860E+05 1.890E+04 21546 4 37 7.0 0.679 1.572E+05 1.183E+04 21546 4 38 7.0 0.769 1.297E+05 1.317E+04 21546 4 39 7.0 0.879 1.237E+05 9.311E+03 21546 4 40 7.0 0.990 1.124E+05 1.142E+04 21546 4 41 7.0 1.079 9.735E+04 1.249E+04 21546 4 42 7.0 1.168 9.285E+04 1.194E+04 21546 4 43 7.0 1.258 7.659E+04 7.781E+03 21546 4 44 7.0 1.368 7.485E+04 5.634E+03 21546 4 45 7.0 1.501 6.643E+04 6.749E+03 21546 4 46 7.0 1.656 6.041E+04 6.120E+03 21546 4 47 7.0 1.833 5.364E+04 5.434E+03 21546 4 48 7.0 1.966 5.119E+04 6.596E+03 21546 4 49 7.0 2.077 4.766E+04 6.128E+03 21546 4 50 7.0 2.188 4.128E+04 5.295E+03 21546 4 51 7.0 2.321 3.753E+04 4.825E+03 21546 4 52 7.0 2.476 3.496E+04 3.542E+03 21546 4 53 7.0 2.609 3.029E+04 3.077E+03 21546 4 54 7.0 2.809 2.626E+04 3.368E+03 21546 4 55 7.0 2.986 2.388E+04 3.064E+03 21546 4 56 7.0 3.186 1.926E+04 2.476E+03 21546 4 57 7.0 3.408 1.591E+04 2.480E+03 21546 4 58 7.0 3.651 1.448E+04 2.266E+03 21546 4 59 7.0 3.939 1.169E+04 1.826E+03 21546 4 60 7.0 4.249 9.903E+03 1.550E+03 21546 4 61 7.0 4.603 7.807E+03 1.220E+03 21546 4 62 7.0 5.001 6.784E+03 1.060E+03 21546 4 63 7.0 5.449 2.996E+03 9.133E+02 21546 4 64 7.0 5.955 2.871E+03 6.983E+02 21546 4 65 7.0 6.528 2.821E+03 6.871E+02 21546 4 66 7.0 7.258 1.797E+03 5.478E+02 21546 4 67 7.0 8.120 1.233E+03 2.994E+02 21546 4 68 7.0 9.082 2.525E+02 3.083E+02 21546 4 69 7.0 9.792 1.357E+02 1.964E+02 21546 4 70 ENDDATA 55 0 21546 4 71 ENDSUBENT 70 0 21546 499999 SUBENT 21546005 20230207 231321546 5 1 BIB 3 4 21546 5 2 REACTION (92-U-238(N,F)0-NN-1,PR,NU/DE,,RRE/REL) 21546 5 3 STATUS (CURVE) Fig.14 of CEA-R-4913 (same on fig.1 of 21546 5 4 Trans.Am.Nuc.Soc.,32,732,1979). 21546 5 5 HISTORY (20230207C) SD 21546 5 6 ENDBIB 4 0 21546 5 7 COMMON 3 3 21546 5 8 E-ERR-DIG ERR-DIG EN 21546 5 9 MEV PER-CENT MEV 21546 5 10 0.016 1.5 7.0 21546 5 11 ENDCOMMON 3 0 21546 5 12 DATA 3 37 21546 5 13 E DATA DATA-ERR 21546 5 14 MEV ARB-UNITS ARB-UNITS 21546 5 15 0.374 1.094E+04 1.476E+03 21546 5 16 0.440 1.178E+04 1.832E+03 21546 5 17 0.527 1.237E+04 1.591E+03 21546 5 18 0.595 1.045E+04 1.065E+03 21546 5 19 0.683 1.021E+04 1.038E+03 21546 5 20 0.773 8.426E+03 8.560E+02 21546 5 21 0.884 7.297E+03 5.512E+02 21546 5 22 0.996 6.474E+03 8.323E+02 21546 5 23 1.064 5.211E+03 8.140E+02 21546 5 24 1.151 5.609E+03 8.778E+02 21546 5 25 1.264 4.003E+03 5.147E+02 21546 5 26 1.374 4.207E+03 5.409E+02 21546 5 27 1.507 3.644E+03 4.685E+02 21546 5 28 1.662 3.314E+03 3.367E+02 21546 5 29 1.818 2.871E+03 3.700E+02 21546 5 30 1.996 2.371E+03 3.048E+02 21546 5 31 2.105 2.492E+03 3.204E+02 21546 5 32 2.215 2.619E+03 3.359E+02 21546 5 33 2.326 2.214E+03 3.458E+02 21546 5 34 2.482 1.965E+03 3.626E+02 21546 5 35 2.637 1.703E+03 2.659E+02 21546 5 36 2.794 1.276E+03 2.354E+02 21546 5 37 2.993 1.189E+03 1.858E+02 21546 5 38 3.214 1.082E+03 1.688E+02 21546 5 39 3.413 9.849E+02 1.817E+02 21546 5 40 3.636 7.038E+02 1.503E+02 21546 5 41 3.942 8.571E+02 1.339E+02 21546 5 42 4.255 5.432E+02 1.002E+02 21546 5 43 4.591 2.838E+02 7.757E+01 21546 5 44 5.053 2.995E+02 8.196E+01 21546 5 45 5.433 1.565E+02 5.790E+01 21546 5 46 5.966 1.019E+02 4.812E+01 21546 5 47 6.582 1.002E+02 5.096E+01 21546 5 48 7.545 1.733E+01 2.940E+01 21546 5 49 8.151 4.938E+01 2.510E+01 21546 5 50 9.060 2.597E+01 1.320E+01 21546 5 51 9.519 3.770E+00 9.820E+00 21546 5 52 ENDDATA 39 0 21546 5 53 ENDSUBENT 52 0 21546 599999 ENDENTRY 5 0 2154699999999