ENTRY 14704 20210421 14841470400000001 SUBENT 14704001 20210421 14841470400100001 BIB 11 43 1470400100002 TITLE Simple Capture of Neutrons by Uranium 1470400100003 AUTHOR (H.L.Anderson,E.Fermi) 1470400100004 REFERENCE (J,PR,55,1106(2),1939) 1470400100005 #doi:10.1103/PhysRev.55.1106.2 1470400100006 INSTITUTE (1USACOL) 1470400100007 FACILITY (CYCLO,1USACOL) 1470400100008 DETECTOR (IOCH) 1470400100009 METHOD (CHSEP,ACTIV) Our measurement was based on a 1470400100010 determination of the number of disintegrations per 1470400100011 second of the 23-minute period of uranium produced by 1470400100012 thermal neutrons and of the number of thermal 1470400100013 neutrons effective under the conditions of 1470400100014 irradiation. The procedure was as follows: (1) 1470400100015 Purification of uranium from uranium X by dissolving 1470400100016 uranyl nitrate in ether and shaking with a small 1470400100017 amount of water, UX and other impurities remain in 1470400100018 the water, while a large fraction of uranium remains 1470400100019 in ether solution and a purified uranyl nitrate may 1470400100020 be obtained by evaporating the ether. (2) Irradiation 1470400100021 inside paraffin by means of the cyclotron with an 1470400100022 indium foil as monitor placed elsewhere in a fixed 1470400100023 position. (3) Second ether purification in order to 1470400100024 separate the 23-minute life from all other activities 1470400100025 which are not due to isotopes of uranium. 1470400100026 (4) Measurement, by means of an ionization chamber, of1470400100027 the decay of the 23-minute life and the growth of the 1470400100028 UX activity. (5) The activation was performed with and1470400100029 without Cd absorbers in order to isolate the 1470400100030 contributions of thermal neutrons. (6) The number of 1470400100031 thermal neutrons for a given indication of the monitor 1470400100032 was obtained by comparing the activity induced in an 1470400100033 indium foil when irradiated either in the uranium 1470400100034 position with the cyclotron or in a paraffin 1470400100035 arrangement of standard geometry. 1470400100036 CORRECTION We have therefore corrected our results for the 1470400100037 absorption of beta-rays in the substance itself, in 1470400100038 the container and in the window of the ionization 1470400100039 chamber, and for the sensitivity of the chamber. The 1470400100040 total correction factor was 3.4. 1470400100041 DECAY-DATA (92-U-239,23.0MIN,B-) 1470400100042 ERR-ANALYS No uncertainties given. Authors mention that large 1470400100043 errors can affect such measurements. 1470400100044 HISTORY (20210421C) BP 1470400100045 ENDBIB 43 0 1470400100046 COMMON 1 3 1470400100047 EN-DUMMY 1470400100048 EV 1470400100049 0.0253 1470400100050 ENDCOMMON 3 0 1470400100051 ENDSUBENT 50 0 1470400199999 SUBENT 14704002 20210421 14841470400200001 BIB 3 6 1470400200002 REACTION (92-U-238(N,G)92-U-239,,SIG) 1470400200003 SAMPLE The uranium position with the cyclotron or in a 1470400200004 paraffin arrangement of standard geometry (center of 1470400200005 the surface of a cylinder of paraffin containing the 1470400200006 source 3 cm below the surface). 1470400200007 STATUS (TABLE) page 1107. 1470400200008 ENDBIB 6 0 1470400200009 NOCOMMON 0 0 1470400200010 DATA 1 1 1470400200011 DATA 1470400200012 B 1470400200013 1.0 1470400200014 ENDDATA 3 0 1470400200015 ENDSUBENT 14 0 1470400299999 SUBENT 14704003 20210421 14841470400300001 BIB 4 5 1470400300002 REACTION (92-U-238(N,G)92-U-239,,SIG) 1470400300003 SAMPLE Mixture of uranium and manganese. 1470400300004 METHOD Determined simultaneously the capture cross sections 1470400300005 for uranium and for manganese. 1470400300006 STATUS (TABLE) page 1107. 1470400300007 ENDBIB 5 0 1470400300008 NOCOMMON 0 0 1470400300009 DATA 1 1 1470400300010 DATA 1470400300011 B 1470400300012 1.2 1470400300013 ENDDATA 3 0 1470400300014 ENDSUBENT 13 0 1470400399999 SUBENT 14704004 20210421 14841470400400001 BIB 4 5 1470400400002 REACTION (25-MN-55(N,G)25-MN-56,,SIG) 1470400400003 SAMPLE Mixture of uranium and manganese. 1470400400004 METHOD Determined simultaneously the capture cross sections 1470400400005 for uranium and for manganese. 1470400400006 STATUS (TABLE) page 1107. 1470400400007 ENDBIB 5 0 1470400400008 NOCOMMON 0 0 1470400400009 DATA 1 1 1470400400010 DATA 1470400400011 B 1470400400012 10.0 1470400400013 ENDDATA 3 0 1470400400014 ENDSUBENT 13 0 1470400499999 ENDENTRY 4 0 1470499999999