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The status of experimental quantum number assignments to low-lying levels of /sup 20/F is reviewed. The use of a Compton-scattering polarimeter of limited resolution but good efficiency, in coincidence with an annular particle detector and perpendicular to the reaction symmetry axis, is described. Measurements of /sup 20/F deexcitation gamma -ray polarization have been carried out following the /sup 18/O(/sup 3/He, p) reaction at 3.8 MeV and 0 deg In conjunction with past experiments, thc following assignments are inferred: 656 KeV, 3/sup +/; 823 keV, 4/sup +/; 984 keV, l-; 1309 keV, 2-; 1824 keV, 51; and 1843 keV, (2-). The relation of the experimental level structure to the rotational band grouping and to the pds shell-model calculation of McGrory and and Wildenthal is illustrated. (auth) H14185 The tensor-analyzing power T/sub 20/ of (d, p) reactions on /sup 12/C, /sup 28/S i and /sup 40/Ca are measured at small angles as a function of bombarding energy. Measurements are carried out for theta /sub lab/ from 0-l5 deg and E/sub d/ from 5-l2 MeV. Strong fluctuations of T/sub 20/ with energy are observed. The measurements are not explained by distonted-wave calculations which neglect the deuteron D state. Inclusion of the D statemore » leads to better agreement with the data. The remaining discrepancy between the D-state calculation and the measured T/sub 20/ can be explained by a compound-nucleus contribution to the reaction mechanism. (auth)« less |
