ENTRY 12445 20210610 14861244500000001 SUBENT 12445001 20210610 14861244500100001 BIB 12 37 1244500100002 TITLE Thermal Neutron Absorption by 28 1244500100003 AUTHOR (H.L.Anderson,J.Bistline,J.Dabbs,H.Heskett,W.Sturm, 1244500100004 J.Tabin) 1244500100005 REFERENCE (R,CP-2079,1944) 1244500100006 INSTITUTE (1USAANL) 1244500100007 FACILITY (REAC,1USAANL) 1244500100008 SAMPLE 2500 grams of depleted U3O8 oxide in which the 1244500100009 ratio of isotopes 238U/235U was 3800. 92 uranium 1244500100010 pellets were produced. Each pellet was 2.57 cm in 1244500100011 diameter, 0.70 cm in height,and weighted 20 grams. 1244500100012 These were held in little Al dishes, each of which 1244500100013 weighed slightly less than 2 grams. The 92 pellets 1244500100014 were arranged inside a graphite brick 10 x 10 x 120 1244500100015 cm long in a cubic lattice of spacing 5.21 cm, 23 1244500100016 periods long. 1244500100017 DETECTOR (PROPC) Low geometry thin mica window counter. 1244500100018 METHOD (REAC,CHSEP) Reactivity coefficient measurement. The 1244500100019 absorption cross section of 238U was measured by 1244500100020 comparing the change in reactivity of a pile produced 1244500100021 by a sample of oxide in which the isotopic ratio was 1244500100022 3800, with that produced by a standard boron 1244500100023 absorber. The temperature of the pile neutrons with 1244500100024 which the measurement was made was found to be 381 K. 1244500100025 Cd wires were used to determine neutron temperature. 1244500100026 After the irradiation the pellets were dissolved in 1244500100027 nitric acid. Five grams of purified material was 1244500100028 pressed into a pellet and the beta-ray activity of 1244500100029 the 23.5 minute half life of 239U was measured. 1244500100030 ERR-ANALYS (DATA-ERR) Data reproducibility error. 1244500100031 STATUS (TABLE) page 12. 1244500100032 DECAY-DATA (92-U-239,23.5MIN,B-) 1244500100033 HISTORY (19760804T) Translated from SCISRS. 1244500100034 (19830809A) Converted to reaction formalism. 1244500100035 (20210610A) BP: Updated to new date formats, lower 1244500100036 case. corrections according last EXFOR rules and 1244500100037 Dict. Added FACILITY, DETECTOR, SAMPLE, ERROR-ANALYSIS,1244500100038 CORRECTION, DECAY-DATA and Sub.3. 1244500100039 ENDBIB 37 0 1244500100040 NOCOMMON 0 0 1244500100041 ENDSUBENT 40 0 1244500199999 SUBENT 12445002 20210610 14861244500200001 BIB 4 10 1244500200002 REACTION (92-U-238(N,G)92-U-239,,SIG) 1244500200003 INC-SPECT Sub-Cd spectrum. 1244500200004 ANALYSIS From the (thermal+resonance)/resonance ratio of 2.649. 1244500200005 0.6225 fraction below the Cd limit: 0.6625 x 4.158 = 1244500200006 2.59 b. From this effect of B and Cd impurities found 1244500200007 in spectrographic analysis had to be subtracted. This 1244500200008 amounted to 0.006 b. The final number of 2.58 b may 1244500200009 have to be reduced slightly if other dangerous 1244500200010 impurities are found. 1244500200011 STATUS (DEP,12445003) 1244500200012 ENDBIB 10 0 1244500200013 COMMON 1 3 1244500200014 EN 1244500200015 EV 1244500200016 0.0253 1244500200017 ENDCOMMON 3 0 1244500200018 DATA 2 1 1244500200019 DATA DATA-ERR 1244500200020 B PER-CENT 1244500200021 2.58 3. 1244500200022 ENDDATA 3 0 1244500200023 ENDSUBENT 22 0 1244500299999 SUBENT 12445003 20210610 14861244500300001 BIB 4 9 1244500300002 REACTION (92-U-238(N,G)92-U-239,,SIG,,MXW) The total 1244500300003 absorption by 238U after corrections. 1244500300004 MONITOR (5-B-0(N,ABS),,SIG) Relative to boron thermal 1244500300005 absorption of 703 b at 2200 m/sec. 1244500300006 CORRECTION Correction of 0.143 b due to the effect of 235U in 1244500300007 the sample was added. In addition, 0.022 b had to be 1244500300008 added to correct for the effect of fast fission in 1244500300009 238U. 1244500300010 HISTORY (20210610C) BP 1244500300011 ENDBIB 9 0 1244500300012 COMMON 2 3 1244500300013 EN-DUMMY MONIT 1244500300014 EV B 1244500300015 0.0253 703.0 1244500300016 ENDCOMMON 3 0 1244500300017 DATA 2 1 1244500300018 DATA DATA-ERR 1244500300019 B PER-CENT 1244500300020 4.158 3. 1244500300021 ENDDATA 3 0 1244500300022 ENDSUBENT 21 0 1244500399999 ENDENTRY 3 0 1244599999999