ENTRY 10821 20210409 14821082100000001 SUBENT 10821001 20210409 14821082100100001 BIB 14 68 1082100100002 TITLE Fast neutron fission of 240Pu 1082100100003 AUTHOR (W.A.Myers,M.V.Kantelo,R.L.Osborne,A.L.Prindle, 1082100100004 D.R.Nethaway) 1082100100005 INSTITUTE (1USALRL) 1082100100006 (1USAUSA) McClellan Central Laboratory, California 1082100100007 REFERENCE (J,PR/C,18,1700,1978) 1082100100008 #doi:10.1103/PhysRevC.18.1700 1082100100009 #NSR: 1978MY02 1082100100010 (J,PR/C,20,1824,1979) Corrected fission yield for 153Sm1082100100011 #doi:10.1103/PhysRevC.20.1824 1082100100012 #NSR: 1979PR09 1082100100013 FACILITY (CRASS,1USALAS) Los Alamos FLATTOP critical assembly 1082100100014 INC-SPECT Slightly degraded fission spectrum. 1082100100015 Spectral indices for neutron distribution are: 1082100100016 -fission cross section ratio U-235/U-238 = 5.8 1082100100017 -ratio capture cross section U-238 to fission cross 1082100100018 section U-238 = 0.46 1082100100019 -ratio (n,2n) cross section U-238 to fission cross 1082100100020 section U-238 = 0.055 1082100100021 SAMPLE PuUO2 targets, ranging from 10 to 200 mg, were doubly 1082100100022 encapsulated in 0.025-mm aluminum foil, sandwiched 1082100100023 between U-235 monitor foils. Entire assembly enclosed 1082100100024 in copper can with 0.1-mm-thick walls. 1082100100025 (94-PU-240,ENR=0.9841) 1082100100026 (94-PU-238,ENR=0.00017) 1082100100027 (94-PU-239,ENR=0.0067) 1082100100028 (94-PU-241,ENR=0.0053) 1082100100029 (94-PU-242,ENR=0.0037) 1082100100030 DETECTOR No information 1082100100031 REL-REF (M,10712001,D.R.Nethaway+,J,PR/C,16,1907,1977) 1082100100032 MONITOR ((MONIT)94-PU-240(N,F)42-MO-99,CUM,FY,,FST) 1082100100033 Relative yields determined as a ratio to that of Mo-99,1082100100034 and the ratios for each product were averaged over all 1082100100035 the experiments. The number of fissions in the Pu-240 1082100100036 targets was calculated from the masses of the Pu-240 1082100100037 and U-235 monitor foils, the fission cross section 1082100100038 ratio Pu-240/U-235 was taken as 0.825 +/- 5%. The 1082100100039 absolute yield of Mo-99 determined in this manner was 1082100100040 0.0636 +/- 0.0038 atoms/fission. 1082100100041 The number of fissions was also calculated by the 1082100100042 requirement of unit total yield in each half of the 1082100100043 mass-yield distribution. This method gave a yield of 1082100100044 0.0600 +/- 0.0030 atoms/fission for Mo-99. 1082100100045 The average of the results from these two methods, 1082100100046 0.0618 atoms/fission, for the yield of Mo-99, was used.1082100100047 METHOD (CHSEP) Three four-hour irradiations. Disintegration 1082100100048 rates of fission products determined with gamma-ray 1082100100049 spectrometry and/or beta-particle assay. Pu-240 1082100100050 content of target determined by mass spectrometry. 1082100100051 Delay in analysis precludes measurements of half-lives1082100100052 less than ten hours. Number of fissions determined as 1082100100053 average of two methods: 1082100100054 .cross section ratio of Pu-240/U-235 and average 1082100100055 number of U-235 fissions. 1082100100056 .summing up each half of mass yield curve. 1082100100057 CORRECTION Corrected for decay during irradiation (10% or less) 1082100100058 and for undecayed parent nuclei. 1082100100059 STATUS (APRVD) Approved by A. L. Prindle, 80/3/3. 1082100100060 HISTORY (19791115C) 1082100100061 (19801029A) Monitor corrected. 1082100100062 (19810309A) REFERENCE added. 1082100100063 (19810720A) Spelling correction. 1082100100064 (19891113A) BIB update. 1082100100065 (20210409A) OG. Converted to lower case and 4-digit 1082100100066 year. #NSR, #doi, REL-REF, STATUS in Sub002-005 added. 1082100100067 SAMPLE, MONITOR, REACTION in Subs.4,5 updated. 1082100100068 EN-DUMMY changed from 0.5 to 1.0 MeV. 1082100100069 ERR-ANALYS updated and moved to Sub002-005. 1082100100070 ENDBIB 68 0 1082100100071 COMMON 3 3 1082100100072 EN-DUMMY MONIT MONIT-ERR 1082100100073 MEV PC/FIS PER-CENT 1082100100074 1.0 6.18 5. 1082100100075 ENDCOMMON 3 0 1082100100076 ENDSUBENT 75 0 1082100199999 SUBENT 10821002 20210409 14821082100200001 BIB 4 8 1082100200002 REACTION (94-PU-240(N,F)ELEM/MASS,CUM,FY,,FST) 1082100200003 ERR-ANALYS (ERR-T) Errors due to 1082100200004 (ERR-1) Uncertainty in number of U-235 fissions, 1% 1082100200005 (ERR-2,,1.) Contribution of Pu-239 fissions < 1% 1082100200006 STATUS (TABLE) Tab.I (p.1702) in Phys.Rev.C18,1700,1978. 1082100200007 HISTORY (19810309U) DATA for Sm-153 corrected as per Phys. 1082100200008 Rev.C 20,1824,1979. 1082100200009 (20210409U) OG. ERR-ANALYS added, DATA-ERR -> ERR-T 1082100200010 ENDBIB 8 0 1082100200011 COMMON 1 3 1082100200012 ERR-1 1082100200013 PER-CENT 1082100200014 1. 1082100200015 ENDCOMMON 3 0 1082100200016 DATA 6 44 1082100200017 ELEMENT MASS ISOMER DATA DATA-MAX ERR-T 1082100200018 NO-DIM NO-DIM NO-DIM PC/FIS PC/FIS PER-CENT 1082100200019 30. 72. 0.000116 3.1 1082100200020 38. 89. 1.49 6.8 1082100200021 38. 90. 1.93 3.0 1082100200022 38. 91. 2.32 3.0 1082100200023 39. 91. 2.35 3.0 1082100200024 39. 93. 3.98 3.0 1082100200025 40. 95. 4.49 3.0 1082100200026 40. 97. 5.28 3.0 1082100200027 41. 96. 0.00232 3.4 1082100200028 42. 99. 6.18 3.0 1082100200029 44. 103. 7.09 3.0 1082100200030 44. 106. 5.12 3.0 1082100200031 45. 105. 5.74 3.0 1082100200032 46. 109. 1.80 4.7 1082100200033 46. 112. 0.234 3.0 1082100200034 47. 111. 0.501 3.0 1082100200035 47. 113. 0. 0.159 9.7 1082100200036 48. 115. 0. 0.0610 3.0 1082100200037 48. 115. 1. 0.00404 3.0 1082100200038 51. 127. 0.447 3.0 1082100200039 52. 131. 1. 0.769 3.0 1082100200040 52. 132. 5.07 3.0 1082100200041 53. 131. 3.92 5.2 1082100200042 53. 133. 7.56 3.6 1082100200043 53. 135. 7.16 3.0 1082100200044 54. 135. 7.26 4.1 1082100200045 55. 134. 0. 0.00041 1082100200046 55. 136. 0.0612 3.0 1082100200047 55. 137. 6.06 3.0 1082100200048 56. 140. 5.46 3.0 1082100200049 58. 141. 4.90 3.0 1082100200050 58. 143. 4.44 3.0 1082100200051 58. 144. 3.97 3.0 1082100200052 60. 147. 2.27 3.0 1082100200053 61. 149. 1.41 3.0 1082100200054 61. 151. 0.842 3.0 1082100200055 62. 153. 0.548 3.0 1082100200056 63. 155. 0.242 3.0 1082100200057 63. 156. 0.172 3.0 1082100200058 63. 157. 0.133 7.7 1082100200059 64. 159. 0.0324 3.0 1082100200060 65. 160. 0.00011 1082100200061 65. 161. 0.0112 3.0 1082100200062 68. 169. 0.00011 1082100200063 ENDDATA 46 0 1082100200064 ENDSUBENT 63 0 1082100299999 SUBENT 10821003 20210409 14821082100300001 BIB 3 7 1082100300002 REACTION (94-PU-240(N,F)MASS,CHN,FY,,FST) 1082100300003 ERR-ANALYS (DATA-ERR) The given experimental standard deviations 1082100300004 do not include the systematic uncertainty in the yield 1082100300005 determination. 1082100300006 (ERR-SYS) The systematic uncertainty in the yield 1082100300007 determination. It is estimated to be about 5%. 1082100300008 STATUS (TABLE) Tab.I (p.1702) in Phys.Rev.C18,1700,1978. 1082100300009 ENDBIB 7 0 1082100300010 COMMON 1 3 1082100300011 ERR-SYS 1082100300012 PER-CENT 1082100300013 5. 1082100300014 ENDCOMMON 3 0 1082100300015 DATA 3 3 1082100300016 MASS DATA DATA-ERR 1082100300017 NO-DIM PC/FIS PC/FIS 1082100300018 91. 2.34 0.05 1082100300019 115. 0.0650 0.0018 1082100300020 135. 7.61 0.35 1082100300021 ENDDATA 5 0 1082100300022 ENDSUBENT 21 0 1082100399999 SUBENT 10821004 20210409 14821082100400001 BIB 5 8 1082100400002 REACTION (94-PU-240(N,F)ELEM/MASS,IND,FY,,FRC/FST) 1082100400003 ASSUMED (ASSUM,94-PU-240(N,F)55-CS-134-M/G,IND,FY/RAT,,FST) 1082100400004 ERR-ANALYS (ERR-T) Errors due to 1082100400005 (ERR-1) Uncertainty in number of U-235 fissions, 1% 1082100400006 (ERR-2,,1.) Contribution of Pu-239 fissions < 1% 1082100400007 STATUS (TABLE) Tab.III (p.1704) in Phys.Rev.C18,1700,1978. 1082100400008 HISTORY (20210409A) REACTION updated. ISOMER in DATA added, 1082100400009 DATA-ERR -> ERR-T 1082100400010 ENDBIB 8 0 1082100400011 COMMON 3 3 1082100400012 ERR-1 ASSUM ASSUM-ERR 1082100400013 PER-CENT NO-DIM NO-DIM 1082100400014 1. 0.53 0.03 1082100400015 ENDCOMMON 3 0 1082100400016 DATA 6 4 1082100400017 ELEMENT MASS ISOMER DATA DATA-MAX ERR-T 1082100400018 NO-DIM NO-DIM NO-DIM NO-DIM NO-DIM NO-DIM 1082100400019 41. 96. 4.72 E-04 1.6 E-051082100400020 55. 134. 0. 5.8 E-05 1082100400021 55. 136. 8.74 E-03 2.6 E-041082100400022 65. 160. 5.5 E-03 1082100400023 ENDDATA 6 0 1082100400024 ENDSUBENT 23 0 1082100499999 SUBENT 10821005 20210409 14821082100500001 BIB 4 6 1082100500002 REACTION (94-PU-240(N,F)MASS,SEC,ZP) 1082100500003 ERR-ANALYS (DATA-ERR) Uncertainty in width of Gaussian charge 1082100500004 dispersion curve is major contributor to quoted error. 1082100500005 STATUS (TABLE) Tab.III (p.1704) in Phys.Rev.C18,1700,1978. 1082100500006 (DEP,10821004) 1082100500007 HISTORY (20210409A) Added SEC to REACTION SF5 1082100500008 ENDBIB 6 0 1082100500009 NOCOMMON 0 0 1082100500010 DATA 4 4 1082100500011 MASS DATA DATA-MAX DATA-ERR 1082100500012 NO-DIM NO-DIM NO-DIM NO-DIM 1082100500013 96. 38.63 0.20 1082100500014 134. 52.38 0.23 1082100500015 136. 53.14 0.14 1082100500016 160. 63.05 0.15 1082100500017 ENDDATA 6 0 1082100500018 ENDSUBENT 17 0 1082100599999 ENDENTRY 5 0 1082199999999