ENTRY 14675 20210309 14821467500000001 SUBENT 14675001 20210309 14821467500100001 BIB 14 35 1467500100002 TITLE Anomalous Scattering of Fast Neutrons 1467500100003 AUTHOR (M.R.MacPhail) 1467500100004 REFERENCE (J,PR,57,669,1940) 1467500100005 #doi:10.1103/PhysRev.57.669 1467500100006 REL-REF (O,14696001,J.R.Dunning,J,PR,45,586,1934) First 1467500100007 measurement with fast neutrons. 1467500100008 INSTITUTE (1USAPTN) 1467500100009 FACILITY (ACCEL,1USAPTN) 1467500100010 INC-SOURCE (D-D) The neutrons were produced by the action of 1467500100011 100 keV deuterons on targets of heavy ice. 1467500100012 DETECTOR (IOCH) A paraffin-lined ionization chamber. 1467500100013 SAMPLE Scatterers were cylindrical and were slightly larger 1467500100014 in diameter than the ionization chamber (4.2 cm) and 1467500100015 between 4 and 6 cm in length. 1467500100016 METHOD The neutron energy was varied by rotating the counter 1467500100017 and scatterer about the target, that is, by varying 1467500100018 the angle theta between the paths of the neutrons and 1467500100019 the deuterons. 1467500100020 ANALYSIS The cross section for a particular scatterer was 1467500100021 calculated from the measured transmission, i.e., the 1467500100022 ratio of the number of neutrons indicated by the 1467500100023 counter with the scatterer in front of it to that 1467500100024 indicated with the scatterer removed, the times being 1467500100025 such that the electroscope deflections in each case 1467500100026 were the same. The possible reactions to be 1467500100027 considered are elastic and inelastic scattering and 1467500100028 neglected too, being about 10**-4 times as probable 1467500100029 as scattering. Inelastic scattering also is 1467500100030 apparently small. 1467500100031 CORRECTION A correction was made for the number of neutrons 1467500100032 deflected by the scatterer into the ionization 1467500100033 chamber on the assumption that the scattering was 1467500100034 isotropic. 1467500100035 STATUS (TABLE) Table I, page 672. 1467500100036 HISTORY (20210309C) BP 1467500100037 ENDBIB 35 0 1467500100038 NOCOMMON 0 0 1467500100039 ENDSUBENT 38 0 1467500199999 SUBENT 14675002 20210309 14821467500200001 BIB 2 2 1467500200002 REACTION (13-AL-27(N,EL)13-AL-27,,SIG) 1467500200003 SAMPLE 10.6 g/cm2. 1467500200004 ENDBIB 2 0 1467500200005 NOCOMMON 0 0 1467500200006 DATA 2 6 1467500200007 EN DATA 1467500200008 MEV B 1467500200009 2.80 2.48 1467500200010 2.65 2.94 1467500200011 2.57 2.94 1467500200012 2.49 2.18 1467500200013 2.41 2.19 1467500200014 2.34 2.49 1467500200015 ENDDATA 8 0 1467500200016 ENDSUBENT 15 0 1467500299999 SUBENT 14675003 20210309 14821467500300001 BIB 2 2 1467500300002 REACTION (12-MG-0(N,EL)12-MG-0,,SIG) 1467500300003 SAMPLE 8.75 g/cm2. 1467500300004 ENDBIB 2 0 1467500300005 NOCOMMON 0 0 1467500300006 DATA 2 6 1467500300007 EN DATA 1467500300008 MEV B 1467500300009 2.80 2.34 1467500300010 2.65 2.54 1467500300011 2.57 2.14 1467500300012 2.49 1.76 1467500300013 2.41 1.94 1467500300014 2.34 2.19 1467500300015 ENDDATA 8 0 1467500300016 ENDSUBENT 15 0 1467500399999 SUBENT 14675004 20210309 14821467500400001 BIB 2 2 1467500400002 REACTION (6-C-0(N,EL)6-C-0,,SIG) 1467500400003 SAMPLE 7.80 g/cm2. 1467500400004 ENDBIB 2 0 1467500400005 NOCOMMON 0 0 1467500400006 DATA 2 6 1467500400007 EN DATA 1467500400008 MEV B 1467500400009 2.80 1.57 1467500400010 2.65 1.45 1467500400011 2.57 1.38 1467500400012 2.49 1.38 1467500400013 2.41 1.39 1467500400014 2.34 1.41 1467500400015 ENDDATA 8 0 1467500400016 ENDSUBENT 15 0 1467500499999 SUBENT 14675005 20210309 14821467500500001 BIB 2 2 1467500500002 REACTION (11-NA-23(N,EL)11-NA-23,,SIG) 1467500500003 SAMPLE 5.73 g/cm2. 1467500500004 ENDBIB 2 0 1467500500005 NOCOMMON 0 0 1467500500006 DATA 2 6 1467500500007 EN DATA 1467500500008 MEV B 1467500500009 2.80 2.38 1467500500010 2.65 2.50 1467500500011 2.57 2.69 1467500500012 2.49 2.69 1467500500013 2.41 2.69 1467500500014 2.34 2.74 1467500500015 ENDDATA 8 0 1467500500016 ENDSUBENT 15 0 1467500599999 SUBENT 14675006 20210309 14821467500600001 BIB 2 2 1467500600002 REACTION (11-NA-CMP(N,EL)11-NA-CMP,,SIG) 1467500600003 SAMPLE Sodium azide (NaN3), 6.78 g/cm2. 1467500600004 ENDBIB 2 0 1467500600005 NOCOMMON 0 0 1467500600006 DATA 2 6 1467500600007 EN DATA 1467500600008 MEV B 1467500600009 2.80 6.13 1467500600010 2.65 6.35 1467500600011 2.57 6.86 1467500600012 2.49 6.50 1467500600013 2.41 6.35 1467500600014 2.34 6.72 1467500600015 ENDDATA 8 0 1467500600016 ENDSUBENT 15 0 1467500699999 SUBENT 14675007 20210309 14821467500700001 BIB 3 5 1467500700002 REACTION (7-N-14(N,EL)7-N-14,,SIG) 1467500700003 ANALYSIS Na cross sections were subtracted from NaN3 to 1467500700004 extract N values. 1467500700005 STATUS (DEP,14675005) 1467500700006 (DEP,14675006) 1467500700007 ENDBIB 5 0 1467500700008 NOCOMMON 0 0 1467500700009 DATA 2 6 1467500700010 EN DATA 1467500700011 MEV B 1467500700012 2.80 1.25 1467500700013 2.65 1.28 1467500700014 2.57 1.39 1467500700015 2.49 1.27 1467500700016 2.41 1.22 1467500700017 2.34 1.33 1467500700018 ENDDATA 8 0 1467500700019 ENDSUBENT 18 0 1467500799999 ENDENTRY 7 0 1467599999999