Masses of T/sub z/ = +5/2 nuclei in the s--d shell from β--decay measurements

In this work the existence of five new T/sub z/ = +5/2 nuclides, 23F, 29Mg, 31Al, 33Si, and 35P, was established; their properties, including mass values, were determined, along with those of 25Ne and 27Na. Two experimental techniques were used, the ''rabbit'' transfer of a solid target and the gas transfer system; some novel features of these are described. A β spectrum of 33Si observed in coincidence with 1848-keV γ rays is shown; a mass excess of -20569 +- 50 keV was derived for 33Si. Attempts to produce 21O were unsuccessful. Comparisons of the measured masses of the T/sub z/ = +5/2 nuclides in the 2s--1d shell with predictions of the Garvey--Kelson mass formulation and with shell-model calculations are shown. The latter produce considerably better agreement with experiment. (3 figures, 1 table) (U.S.)