ENTRY 20461 19840120 00002046100000001 SUBENT 20461001 19840120 00002046100100001 BIB 16 57 2046100100002 INSTITUTE (2UK HAR) 2046100100003 REFERENCE (J,JNE,24,269,7009) 2046100100004 (R,AERE-R-6350,7003) SAME AS ABOVE 2046100100005 SEE ALSO 2046100100006 (C,66PARIS,2,117,6610) FOR EXPERIMENTAL DETAILS AND 2046100100007 THE METHOD OF REDUCTION OF THE DATA. 2046100100008 (W,SCHOMBERG,7105) DATA ON MAGNETIC TAPE. 2046100100009 AUTHOR (B.H.PATRICK, M.G.SOWERBY, M.G.SCHOMBERG) 2046100100010 TITLE -STRUCTURE IN THE FISSION CROSS-SECTION OF U-235.- 2046100100011 FACILITY (LINAC) THE 45 MEV HARWELL LINEAR ACCELERATOR. 2046100100012 INC-SOURCE (PHOTO)) PHOTO-NEUTRON WITH BOOSTER, TAKING DECAY 2046100100013 TIME OF THE BOOSTER INTO ACCOUNT, THE NOMINAL 2046100100014 RESOLUTION WAS 2 NSEC/M. 2046100100015 SAMPLE .A DISC OF 93 PERCENT U-235, 7.9 CM DIAMETER 2046100100016 AND A THICKNESS OF 1.086 * E-3 ATOMS U-235/BARN. 2046100100017 METHOD (TOF ) TIME OF FLIGHT, FLIGHT PATH = 97.5 M. 2046100100018 DETECTOR (SCIN) THE LIQUID SCINTILLATION COUNTERS USING 2046100100019 PULSE SHAPE DISCRIMINATION TO REJECT GAMMA RAY EVENTS.2046100100020 THE INCIDENT NEUTRON SPECTRUM WAS MEASURED WITH A 2046100100021 (SCIN ) 0.32 CM THICK LI GLASS SCINTILLATOR, A 2046100100022 NE 905, AND A PHOTOMULTIPLIER MOUNTED DIRECTLY BEHIND 2046100100023 IT BUT SEPARATED FROM THE SCINTILLATOR BY 5.25 CM AIR 2046100100024 TO REDUCE THE EFFCT OF SCATTERED NEUTRONS FROM PHOTO- 2046100100025 MULTIPLIER. 2046100100026 ANALYSIS AT LOWER ENERGIES, WHERE THE PEAK X-SECTS. ARE HIGH, 2046100100027 N*SIGMA IS MUCH LARGER THAN 1 AND THE FISS.NEUT.YIELD 2046100100028 IS ROUGHLY PROPORTIONAL TO ETA. 2046100100029 AT HIGHER ENERGIES, N*SIGMA IS MUCH LESS THAN 1 AND 2046100100030 THE FISS.NEUT.YIELD IS PROPORTIONAL TO THE FISSION 2046100100031 X-SECT. WHICH IS THEREFORE MEASURED DIRECTLY. 2046100100032 THE FISSION X-SECT. IS THUS FOUND FROM A COMBINATION 2046100100033 OF TRANSMISSION, YIELD AND SPECTRUM MEASUREMENTS. 2046100100034 .SINCE THE RATIO GAMMA-N/GAMMA IS VERY SMALL IN U-235, 2046100100035 THE SCATTERING X-SECT. IS ASSUMED TO BE EQUAL TO 2046100100036 THE POTENTIAL SCATTERING CROSS SECTION OF 11.70 BARNS 2046100100037 DEDUCED BY UTTLEY, AERE-M 1272 (1963). 2046100100038 .(PROMPT NU-BAR) IS ASSUMED TO HAVE CONSTANT VALUE OF 2046100100039 2.430. 2046100100040 MONITOR (92-U-235(N,ABS),,ETA) 2046100100041 = 1.64 ON THE PEAK OF THE 2046100100042 56.3 EV RESONANCE, TAKEN FROM 2046100100043 DE SAUSSURE+, ORNL-TM-1804(1976). 2046100100044 PART-DET (N ) NEUTRONS. 2046100100045 COMMENT AS A CONCLUSION, THE FISSION CROSS-SECTION OF U-235 2046100100046 SHOWS A PRONOUNCED STRUCTURE OF MAGNITUDE VARYING 2046100100047 FROM UP TO 30 PER CENT IN THE REGION OF 20 KEV TO AT 2046100100048 LEAST 5-10 PERC. NEAR 100 KEV AND THE 2046100100049 ASSUMPTIONS THAT THE CROSS-SECTION IS SMOOTH ARE 2046100100050 CERTAINLY NOT VALID. 2046100100051 HISTORY (710209C) 2046100100052 (760112E) 2046100100053 CORRECTION IN THE CALCULATION OF THE FISSION CROSS SECTION, 2046100100054 CORRECTIONS ARE MADE FOR MULTIPLE SCATTERING EFFECTS, 2046100100055 TAKING THE ENERGY LOSS OF THE NEUTRON INTO ACCOUNT. 2046100100056 ERR-ANALYS DATA ERRORS GIVEN ARE STATISTICAL ERRORS AND DO NOT 2046100100057 INCLUDE A SYSTEMATIC ERROR OF 8 PERCENT, DUE MAINLY 2046100100058 TO UNCERTAINTY IN THE NORMALIZATION AND BACKGROUND. 2046100100059 ENDBIB 57 0 2046100100060 NOCOMMON 0 0 2046100100061 ENDSUBENT 60 0 2046100199999 SUBENT 20461002 19840120 00002046100200001 BIB 3 4 2046100200002 REACTION (92-U-235(N,F),,SIG) 2046100200003 STATUS PRIV.COMM., MAY 71. 2046100200004 HISTORY (710209C) 2046100200005 (760112E) 2046100200006 ENDBIB 4 0 2046100200007 NOCOMMON 0 0 2046100200008 DATA 2 239 2046100200009 EN DATA 2046100200010 MEV B 2046100200011 1.0003E-02 3.1300E+00 2046100200012 1.0039E-02 2.9300E+00 2046100200013 1.0074E-02 3.0300E+00 2046100200014 1.0110E-02 2.7700E+00 2046100200015 1.0147E-02 2.9800E+00 2046100200016 1.0183E-02 3.0201E+00 2046100200017 1.0219E-02 2.8401E+00 2046100200018 1.0256E-02 2.9001E+00 2046100200019 1.0293E-02 2.9001E+00 2046100200020 1.0330E-02 2.8602E+00 2046100200021 1.0368E-02 2.8502E+00 2046100200022 1.0405E-02 2.7302E+00 2046100200023 1.0443E-02 2.8802E+00 2046100200024 1.0481E-02 2.7003E+00 2046100200025 1.0519E-02 2.9003E+00 2046100200026 1.0557E-02 2.8403E+00 2046100200027 1.0596E-02 2.9704E+00 2046100200028 1.0634E-02 2.8104E+00 2046100200029 1.0673E-02 2.7904E+00 2046100200030 1.0713E-02 2.7705E+00 2046100200031 1.0752E-02 3.1106E+00 2046100200032 1.0792E-02 2.8406E+00 2046100200033 1.0832E-02 2.8106E+00 2046100200034 1.0872E-02 2.6406E+00 2046100200035 1.0912E-02 2.8207E+00 2046100200036 1.0952E-02 2.9808E+00 2046100200037 1.0993E-02 2.6908E+00 2046100200038 1.1034E-02 2.7408E+00 2046100200039 1.1075E-02 2.8509E+00 2046100200040 1.1117E-02 2.8110E+00 2046100200041 1.1158E-02 2.9511E+00 2046100200042 1.1200E-02 3.1412E+00 2046100200043 1.1243E-02 2.8812E+00 2046100200044 1.1285E-02 2.7211E+00 2046100200045 1.1327E-02 2.8513E+00 2046100200046 1.1370E-02 2.9314E+00 2046100200047 1.1413E-02 2.6913E+00 2046100200048 1.1457E-02 2.8815E+00 2046100200049 1.1500E-02 2.7915E+00 2046100200050 1.1544E-02 2.7115E+00 2046100200051 1.1588E-02 2.5615E+00 2046100200052 1.1633E-02 2.5916E+00 2046100200053 1.1677E-02 2.6116E+00 2046100200054 1.1722E-02 2.5917E+00 2046100200055 1.1767E-02 2.6218E+00 2046100200056 1.1813E-02 2.5018E+00 2046100200057 1.1858E-02 2.6820E+00 2046100200058 1.1904E-02 2.6920E+00 2046100200059 1.1950E-02 2.8422E+00 2046100200060 1.1997E-02 2.6822E+00 2046100200061 1.2043E-02 2.8024E+00 2046100200062 1.2090E-02 2.5823E+00 2046100200063 1.2138E-02 2.7325E+00 2046100200064 1.2185E-02 2.7426E+00 2046100200065 1.2233E-02 2.5725E+00 2046100200066 1.2281E-02 2.4124E+00 2046100200067 1.2330E-02 2.5426E+00 2046100200068 1.2378E-02 2.4926E+00 2046100200069 1.2427E-02 2.2725E+00 2046100200070 1.2476E-02 2.3927E+00 2046100200071 1.2526E-02 2.3828E+00 2046100200072 1.2576E-02 2.4329E+00 2046100200073 1.2626E-02 2.5632E+00 2046100200074 1.2676E-02 2.3029E+00 2046100200075 1.2727E-02 2.2930E+00 2046100200076 1.2778E-02 2.5534E+00 2046100200077 1.2830E-02 2.5135E+00 2046100200078 1.2881E-02 2.2131E+00 2046100200079 1.2933E-02 2.5938E+00 2046100200080 1.2986E-02 2.5037E+00 2046100200081 1.3038E-02 2.6140E+00 2046100200082 1.3091E-02 2.5540E+00 2046100200083 1.3144E-02 2.8045E+00 2046100200084 1.3198E-02 2.6544E+00 2046100200085 1.3252E-02 2.8148E+00 2046100200086 1.3306E-02 2.9251E+00 2046100200087 1.3361E-02 2.8952E+00 2046100200088 1.3416E-02 2.8352E+00 2046100200089 1.3471E-02 2.8153E+00 2046100200090 1.3526E-02 2.7252E+00 2046100200091 1.3582E-02 2.7253E+00 2046100200092 1.3639E-02 2.7656E+00 2046100200093 1.3695E-02 2.5753E+00 2046100200094 1.3752E-02 2.5053E+00 2046100200095 1.3810E-02 2.3350E+00 2046100200096 1.3867E-02 2.3953E+00 2046100200097 1.3925E-02 2.4455E+00 2046100200098 1.3984E-02 2.4857E+00 2046100200099 1.4043E-02 2.3656E+00 2046100200100 1.4102E-02 2.4860E+00 2046100200101 1.4161E-02 2.3257E+00 2046100200102 1.4221E-02 2.2456E+00 2046100200103 1.4282E-02 2.2057E+00 2046100200104 1.4342E-02 2.0754E+00 2046100200105 1.4403E-02 2.1858E+00 2046100200106 1.4465E-02 2.2060E+00 2046100200107 1.4527E-02 2.2362E+00 2046100200108 1.4589E-02 2.2063E+00 2046100200109 1.4652E-02 2.1964E+00 2046100200110 1.4715E-02 2.4673E+00 2046100200111 1.4778E-02 2.3672E+00 2046100200112 1.4842E-02 2.4977E+00 2046100200113 1.4906E-02 2.6684E+00 2046100200114 1.4971E-02 2.5883E+00 2046100200115 1.5036E-02 2.6186E+00 2046100200116 1.5102E-02 2.4883E+00 2046100200117 1.5168E-02 2.3480E+00 2046100200118 1.5234E-02 2.1374E+00 2046100200119 1.5301E-02 2.1074E+00 2046100200120 1.5368E-02 2.1979E+00 2046100200121 1.5436E-02 2.1479E+00 2046100200122 1.5504E-02 2.2183E+00 2046100200123 1.5573E-02 2.2988E+00 2046100200124 1.5642E-02 2.0981E+00 2046100200125 1.5712E-02 2.1886E+00 2046100200126 1.5782E-02 2.3796E+00 2046100200127 1.5852E-02 2.5203E+00 2046100200128 1.5923E-02 2.2594E+00 2046100200129 1.5995E-02 2.4002E+00 2046100200130 1.6066E-02 2.3501E+00 2046100200131 1.6139E-02 2.3704E+00 2046100200132 1.6212E-02 2.3505E+00 2046100200133 1.6285E-02 2.3507E+00 2046100200134 1.6359E-02 2.2303E+00 2046100200135 1.6434E-02 2.2004E+00 2046100200136 1.6509E-02 2.2408E+00 2046100200137 1.6584E-02 2.4118E+00 2046100200138 1.6660E-02 2.3517E+00 2046100200139 1.6736E-02 2.3418E+00 2046100200140 1.6814E-02 2.3521E+00 2046100200141 1.6891E-02 2.3020E+00 2046100200142 1.6969E-02 2.2620E+00 2046100200143 1.7048E-02 2.2321E+00 2046100200144 1.7127E-02 2.1719E+00 2046100200145 1.7207E-02 2.2928E+00 2046100200146 1.7287E-02 2.2629E+00 2046100200147 1.7368E-02 2.2228E+00 2046100200148 1.7449E-02 2.1627E+00 2046100200149 1.7531E-02 2.1730E+00 2046100200150 1.7614E-02 2.2637E+00 2046100200151 1.7697E-02 2.3545E+00 2046100200152 1.7781E-02 2.3447E+00 2046100200153 1.7865E-02 2.3651E+00 2046100200154 1.7950E-02 2.2948E+00 2046100200155 1.8036E-02 2.4864E+00 2046100200156 1.8122E-02 2.4463E+00 2046100200157 1.8208E-02 2.3661E+00 2046100200158 1.8296E-02 2.3160E+00 2046100200159 1.8384E-02 2.3061E+00 2046100200160 1.8473E-02 2.4373E+00 2046100200161 1.8562E-02 2.3772E+00 2046100200162 1.8652E-02 2.4782E+00 2046100200163 1.8743E-02 2.5389E+00 2046100200164 1.8834E-02 2.5392E+00 2046100200165 1.8926E-02 2.4690E+00 2046100200166 1.9018E-02 2.5600E+00 2046100200167 1.9112E-02 2.6107E+00 2046100200168 1.9206E-02 2.4900E+00 2046100200169 1.9300E-02 2.3895E+00 2046100200170 1.9396E-02 2.3898E+00 2046100200171 1.9492E-02 2.2490E+00 2046100200172 1.9589E-02 2.3098E+00 2046100200173 1.9686E-02 2.1789E+00 2046100200174 1.9784E-02 2.1792E+00 2046100200175 1.9883E-02 2.3813E+00 2046100200176 1.9983E-02 2.1697E+00 2046100200177 2.0084E-02 2.3315E+00 2046100200178 2.0185E-02 2.3318E+00 2046100200179 2.0287E-02 2.2514E+00 2046100200180 2.0390E-02 2.3224E+00 2046100200181 2.0493E-02 2.2015E+00 2046100200182 2.0598E-02 1.9897E+00 2046100200183 2.0703E-02 2.0204E+00 2046100200184 2.0809E-02 2.1116E+00 2046100200185 2.0916E-02 2.0816E+00 2046100200186 2.1024E-02 2.0112E+00 2046100200187 2.1132E-02 2.0115E+00 2046100200188 2.1241E-02 1.9815E+00 2046100200189 2.1351E-02 1.9413E+00 2046100200190 2.1463E-02 1.9619E+00 2046100200191 2.1574E-02 2.0330E+00 2046100200192 2.1687E-02 2.3672E+00 2046100200193 2.1801E-02 2.3473E+00 2046100200194 2.1915E-02 2.4186E+00 2046100200195 2.2031E-02 2.4190E+00 2046100200196 2.2147E-02 2.5308E+00 2046100200197 2.2264E-02 2.4502E+00 2046100200198 2.2383E-02 2.7038E+00 2046100200199 2.2502E-02 2.4916E+00 2046100200200 2.2622E-02 2.4515E+00 2046100200201 2.2743E-02 2.5128E+00 2046100200202 2.2865E-02 2.2599E+00 2046100200203 2.2988E-02 2.0880E+00 2046100200204 2.3112E-02 2.1797E+00 2046100200205 2.3237E-02 2.0280E+00 2046100200206 2.3363E-02 1.9270E+00 2046100200207 2.3490E-02 2.0694E+00 2046100200208 2.3619E-02 2.1104E+00 2046100200209 2.3748E-02 2.2021E+00 2046100200210 2.3878E-02 2.0402E+00 2046100200211 2.4009E-02 2.0914E+00 2046100200212 2.4142E-02 2.1934E+00 2046100200213 2.4275E-02 2.1736E+00 2046100200214 2.4410E-02 2.2756E+00 2046100200215 2.4546E-02 2.1339E+00 2046100200216 2.4683E-02 2.2360E+00 2046100200217 2.4821E-02 2.2467E+00 2046100200218 2.4960E-02 2.1353E+00 2046100200219 2.5100E-02 2.1765E+00 2046100200220 2.5242E-02 2.2279E+00 2046100200221 2.5384E-02 2.1165E+00 2046100200222 2.5529E-02 2.0661E+00 2046100200223 2.5674E-02 2.1481E+00 2046100200224 2.5820E-02 2.0468E+00 2046100200225 2.5968E-02 2.0269E+00 2046100200226 2.6117E-02 1.9255E+00 2046100200227 2.6267E-02 1.9974E+00 2046100200228 2.6419E-02 2.0489E+00 2046100200229 2.6571E-02 2.0392E+00 2046100200230 2.6726E-02 2.1112E+00 2046100200231 2.6881E-02 2.0505E+00 2046100200232 2.7038E-02 2.0409E+00 2046100200233 2.7196E-02 1.9190E+00 2046100200234 2.7356E-02 1.9604E+00 2046100200235 2.7517E-02 1.9201E+00 2046100200236 2.7680E-02 2.0126E+00 2046100200237 2.7844E-02 2.1256E+00 2046100200238 2.8009E-02 2.0342E+00 2046100200239 2.8176E-02 2.0757E+00 2046100200240 2.8344E-02 2.1582E+00 2046100200241 2.8514E-02 2.1589E+00 2046100200242 2.8686E-02 2.0777E+00 2046100200243 2.8859E-02 2.1295E+00 2046100200244 2.9033E-02 2.1097E+00 2046100200245 2.9209E-02 2.0694E+00 2046100200246 2.9387E-02 2.0496E+00 2046100200247 2.9567E-02 2.0503E+00 2046100200248 2.9748E-02 1.8562E+00 2046100200249 2.9930E-02 1.8671E+00 2046100200250 ENDDATA 241 0 2046100200251 ENDSUBENT 250 0 2046100299999 SUBENT 20461003 19840120 00002046100300001 BIB 4 6 2046100300002 REACTION (92-U-235(N,F),,SIG,,AV) 2046100300003 COMMENT THE RESULTS SHOW THAT THE AVERAGE CROSS-SECTION VARIES2046100300004 BY AS MUCH AS 15 PER CENT FROM INTERVAL TO INTERVAL. 2046100300005 STATUS DATA FROM TABLE 1, PAG. 272 OF JNE,24,269. 2046100300006 HISTORY (710209C) 2046100300007 (760112E) 2046100300008 ENDBIB 6 0 2046100300009 NOCOMMON 0 0 2046100300010 DATA 3 5 2046100300011 EN-MAX EN-MIN DATA 2046100300012 MEV MEV B 2046100300013 2.1000E-02 2.0000E-02 2.1800E+00 2046100300014 2.2000E-02 2.1000E-02 2.1200E+00 2046100300015 2.3000E-02 2.2000E-02 2.4300E+00 2046100300016 2.4000E-02 2.3000E-02 2.0800E+00 2046100300017 2.5000E-02 2.4000E-02 2.1800E+00 2046100300018 ENDDATA 7 0 2046100300019 ENDSUBENT 18 0 2046100399999 ENDENTRY 3 0 2046199999999