ENTRY 13494 20210915 14911349400000001 SUBENT 13494001 20210915 14911349400100001 BIB 15 46 1349400100002 TITLE Neutron-Capture Cross Section of 85-Minute Ba139 1349400100003 AUTHOR (L.Yaffe,B.W.Sargent,M.Kirsch,S.Standil,J.M.Grunlund) 1349400100004 REFERENCE (J,PR,76,617,1949) 1349400100005 #doi:10.1103/PhysRev.76.617 1349400100006 INSTITUTE (1CANCRC) 1349400100007 FACILITY (REAC,1CANCRC) Heavy-water pile. 1349400100008 INC-SPECT The fluxes of thermal neutrons were obtained by 1349400100009 experiment as far as possible; the maximum used was 1349400100010 2.0*10**13 neutrons/cm2/sec. 1349400100011 DETECTOR (GEMUC) Counter had a mica end-window of mass 2.8 mg 1349400100012 per cm2. The counter efficiency was found to be 7.5% 1349400100013 using a standard Co60 source. 1349400100014 SAMPLE Barium carbonate (138Ba was 71.66% of natural barium 1349400100015 in 1949 catalogs). 1349400100016 METHOD (ACTIV,CHSEP) It is preferable to produce the Ba139 1349400100017 by neutron capture in stable Ba138 than to separate 1349400100018 it from mixed fission products. Barium carbonate 1349400100019 (analytical reagent grade) was irradiated in high flux1349400100020 positions in the heavy water pile. To free the barium 1349400100021 from lanthanum after irradiation, the procedure was 1349400100022 in each case to dissolve the sample in dilute 1349400100023 hydrochloric acid, and take an aliquot from which the 1349400100024 barium content was determined as barium sulfate. The 1349400100025 La140 samples were mounted on aluminum trays, 7.1 cm2 1349400100026 area, and the activity measured with a previously 1349400100027 calibrated Geiger-Muller counter. The decay curve of 1349400100028 a lanthanum sample was followed for some time. 1349400100029 DECAY-DATA (56-BA-139,85.MIN) 1349400100030 (57-LA-140,41.HR,B-) 1349400100031 ASSUMED (ASSUM,56-BA-138(N,G)56-BA-139,,SIG,,SPA) 1349400100032 MONITOR (57-LA-139(N,G)57-LA-140,,SIG,,SPA) Flux monitor. 1349400100033 MONIT-REF ((MONIT)11447094,L.Seren+,J,PR,72,888,1947) 1349400100034 CORRECTION Corrected for: 1349400100035 - residual background due to barium contamination of 1349400100036 separated 140La 1349400100037 - self-absorption of betas in sample (about 5%) 1349400100038 - external absorption Be air gap and counter window 1349400100039 (about 3%) 1349400100040 - backscattering by Al tray (about 20%) 1349400100041 - counter efficiency 1349400100042 - percentage chemical recovery 1349400100043 HISTORY (19910718C) 1349400100044 (20210915A) BP: Updated to new date formats, lower 1349400100045 case. Corrections according last EXFOR 1349400100046 rules and Dict. Updated entry, added doi 1349400100047 and experimental details. 1349400100048 ENDBIB 46 0 1349400100049 NOCOMMON 0 0 1349400100050 ENDSUBENT 49 0 1349400199999 SUBENT 13494002 20210915 14911349400200001 BIB 3 6 1349400200002 REACTION (56-BA-139(N,G)56-BA-140,,SIG,,SPA) 1349400200003 ERR-ANALYS (DATA-ERR) Estimated probable error. Authors feel 1349400200004 that 1.2 barns is sufficient for the probable error 1349400200005 in our measured value of 4.7 barns because of 20% 1349400200006 probable errors for Ba138 and La139 cross sections. 1349400200007 STATUS (TABLE) Table II, page 619; page 620. 1349400200008 ENDBIB 6 0 1349400200009 NOCOMMON 0 0 1349400200010 DATA 5 1 1349400200011 EN-DUMMY DATA DATA-ERR ASSUM MONIT 1349400200012 EV B B B B 1349400200013 0.0253 4.7 1.2 0.511 8.4 1349400200014 ENDDATA 3 0 1349400200015 ENDSUBENT 14 0 1349400299999 ENDENTRY 2 0 1349499999999