ENTRY 13824 20110927 13751382400000001 SUBENT 13824001 20110927 13751382400100001 BIB 5 6 1382400100002 INSTITUTE (1USALAS) 1382400100003 REFERENCE (J,PR,103,662,195608) 1382400100004 AUTHOR (L.Cranberg,G.Frye,N.Nereson,L.Rosen) 1382400100005 TITLE Fission Neutron Spectrum of U235 1382400100006 HISTORY (20020530C) IS + VM 1382400100007 (20110915A) OS. REACTION and other corr. in subs.2,3 1382400100008 ENDBIB 6 0 1382400100009 NOCOMMON 0 0 1382400100010 ENDSUBENT 9 0 1382400199999 SUBENT 13824002 20110927 13751382400200001 BIB 12 29 1382400200002 REACTION (92-U-235(N,F),,NU/DE,,MXW/REL) 1382400200003 FACILITY (REAC,1USALAS) Los Alamos water boiler reactor. 1382400200004 INC-SOURCE (REAC) Thermal Neutrons (Cd ratio 106). 1382400200005 SAMPLE 4.5" x 6" x 0.03" 235U foil. 1382400200006 METHOD (REC) Measured recoil protons. 1382400200007 DETECTOR (PLATE) Ilford C-2 emulsion plates of 200 micron 1382400200008 thickness used to determine the proton recoils. Plates1382400200009 surrounded by cadmium to inhibit thermal-neutron- 1382400200010 induced N14(n,p)C14 reactions in the emulsion. 1382400200011 MONITOR (1-H-1(N,EL)1-H-1,,SIG) 1382400200012 ANALYSIS Determined orientation of each proton recoil trajectory1382400200013 with respect to the incident neutron direction energy 1382400200014 of each neutron obtained from energy of corresponding 1382400200015 proton recoil. 1382400200016 CORRECTION Data corrected for: 1382400200017 . background using runs with and without shadow 1382400200018 scatterer (polyethylene pyramid) between source 1382400200019 and detector (l4% at 0.3 MeV, 6% at 0.5 MeV, 3% at 1382400200020 1.0 MeV, and 1% at 2.0 MeV). 1382400200021 . knock-on protons leaving the emulsion surfaces. 1382400200022 ERR-ANALYS (ERR-S) Statistical uncertainty. 1382400200023 (ERR-SYS) Systematic uncertainty due to uncertainties 1382400200024 in: 1382400200025 . determination of the solid angle of acceptance of 1382400200026 proton recoils, 1382400200027 . hydrogen content of the emulsion volume analyzed, 1382400200028 . n-p scattering cross section. 1382400200029 STATUS (TABLE) Data taken from Table I in reference. 1382400200030 HISTORY (20110915A) OS. REACTION code, error heading, BIB corr.1382400200031 ENDBIB 29 0 1382400200032 COMMON 1 3 1382400200033 EN-DUMMY 1382400200034 EV 1382400200035 0.0253 1382400200036 ENDCOMMON 3 0 1382400200037 DATA 6 34 1382400200038 E-MIN E-MAX DATA ERR-S ERR-SYS MONIT 1382400200039 MEV MEV ARB-UNITS PER-CENT PER-CENT B 1382400200040 0.3 0.4 823. 4.7 15. 7.65 1382400200041 0.4 0.6 850. 3.1 6. 6.30 1382400200042 0.6 0.8 870. 3.1 6. 5.28 1382400200043 0.8 1.0 754. 3.7 6. 4.57 1382400200044 1.0 1.2 775. 3.7 4. 4.05 1382400200045 1.2 1.4 765. 3.9 4. 3.72 1382400200046 1.4 1.6 663. 4.4 4. 3.42 1382400200047 1.6 1.8 593. 4.8 4. 3.20 1382400200048 1.8 2.0 535. 5.2 4. 3.00 1382400200049 2.0 2.2 491. 6.2 4. 2.85 1382400200050 2.2 2.4 450. 6.6 4. 2.75 1382400200051 2.4 2.6 434. 6.1 4. 2.60 1382400200052 2.6 2.8 350. 6.9 4. 2.50 1382400200053 2.8 3.0 296. 7.7 4. 2.40 1382400200054 3.0 3.2 271. 8.5 5. 2.25 1382400200055 3.2 3.4 269. 8.6 5. 2.16 1382400200056 3.4 3.6 256. 9.1 5. 2.07 1382400200057 3.6 3.8 200. 10.6 5. 2.00 1382400200058 3.8 4.0 219. 8.1 5. 1.93 1382400200059 4.0 4.4 139. 6.2 5. 1.83 1382400200060 4.4 4.8 117. 5.6 5. 1.72 1382400200061 4.8 5.2 85.9 6.1 5. 1.62 1382400200062 5.2 5.6 65.9 6.1 5. 1.53 1382400200063 5.6 6.0 49.3 6.4 5. 1.46 1382400200064 6.0 6.4 40.3 7.4 5. 1.38 1382400200065 6.4 6.8 28.7 9.1 5. 1.32 1382400200066 6.8 7.2 20.2 11.2 5. 1.26 1382400200067 7.2 7.6 15.1 13.5 5. 1.20 1382400200068 7.6 8.0 12.6 15.6 5. 1.16 1382400200069 8.0 8.8 6.8 14.3 5. 1.09 1382400200070 8.8 9.6 2.0 31.2 5. 1.00 1382400200071 9.6 10.4 2.1 33.3 5. 0.930 1382400200072 10.4 11.2 1.4 50. 5. 0.865 1382400200073 11.2 12.8 0.48 70. 5. 0.792 1382400200074 ENDDATA 36 0 1382400200075 ENDSUBENT 74 0 1382400299999 SUBENT 13824003 20110927 13751382400300001 BIB 11 34 1382400300002 REACTION (92-U-235(N,F),,NU/DE,,AV/REL) 1382400300003 FACILITY (VDG,1USALAS) Los Alamos Van de Graaff accelerator. 1382400300004 INC-SOURCE (P-LI7) Neutron energy range from 5 to 80 keV. 1382400300005 SAMPLE 1 g of 235U in the form of UO3, coated in a spiral 1382400300006 fission chamber on approximately 10 spiral turns of 1382400300007 platinum foil. To randomize the layer orientation, 1382400300008 the axis of the spiral was perpendicular to the 1382400300009 direction of neutron detection. 1382400300010 DETECTOR (SCIN) "Scintilon" plastic mounted on a photomultiplier1382400300011 tube cooled to temperature of 0 C. Neutrons detected 1382400300012 by proton recoil in the scintillator. 1382400300013 (LONGC) Long counter used to monitor incident neutrons.1382400300014 METHOD (TOF)Measured time of flight of fission neutrons to 1382400300015 scintillator; 50 cm flight path. Energy resolution 1382400300016 over low-energy region of spectrum is ~15%, obtained 1382400300017 by pulsing proton beam of Van de Graaff accelerator. 1382400300018 ANALYSIS Relative efficiency of "Scintilon" plastic determined 1382400300019 by comparing its response to monochromatic neutrons 1382400300020 with the response of the long counter. 1382400300021 Li(p,n) and T(p,n) reactions used to calibrate 1382400300022 scintillator. 1382400300023 CORRECTION Data corrected for background by taking runs with a 1382400300024 polyethylene cone inserted between the source and 1382400300025 detector. 1382400300026 ERR-ANALYS (ERR-S) Statistical uncertainty. 1382400300027 (ERR-1,,4.) Effect on calculated energy distribution 1382400300028 (below 0.5 MeV), due to width of resolution function, 1382400300029 estimated to be not greater than 4%. 1382400300030 (ERR-2) Systematic uncertainty in energy correction 1382400300031 factors for detector estimated to be about 2%. 1382400300032 (DATA-ERR) Approximate value of the total uncertainty. 1382400300033 STATUS (TABLE) Data taken from Table II in reference. 1382400300034 HISTORY (20110915A) OS. REACTION code, error analysis, 1382400300035 BIB corr. 1382400300036 ENDBIB 34 0 1382400300037 COMMON 3 3 1382400300038 EN-MIN EN-MAX ERR-2 1382400300039 KEV KEV PER-CENT 1382400300040 5. 80. 2. 1382400300041 ENDCOMMON 3 0 1382400300042 DATA 5 12 1382400300043 E-MIN E-MAX DATA ERR-S DATA-ERR 1382400300044 MEV MEV ARB-UNITS ARB-UNITS PER-CENT 1382400300045 2.24 3.23 1740. 50. 5. 1382400300046 1.65 2.24 2520. 75. 5. 1382400300047 1.26 1.65 3480. 100. 5. 1382400300048 1.00 1.26 3830. 130. 5. 1382400300049 0.81 1.00 4130. 160. 10. 1382400300050 0.67 0.81 3890. 170. 10. 1382400300051 0.56 0.67 4040. 210. 10. 1382400300052 0.40 0.56 4140. 160. 10. 1382400300053 0.31 0.40 4350. 220. 10. 1382400300054 0.24 0.31 3680. 250. 10. 1382400300055 0.19 0.24 3420. 280. 10. 1382400300056 0.16 0.19 3370. 340. 10. 1382400300057 ENDDATA 14 0 1382400300058 ENDSUBENT 57 0 1382400399999 ENDENTRY 3 0 1382499999999