Nuclear Physics A411 (1983) 151-160 @ North-Holland Publishing Company MASS EXCESSES OF 79A~, *lAs, AND *‘Ge C.-A. WIEDNER, R. HAUPT, W. SAATHOFF, J. HAAS, R. GYUFKO and K.R. CORDELL zyxwvutsrqponmlkjihgfedcbaZYXWVUT Max-Planck-Institut fiir Kernphy sik, D-6900 Heidelberg, Federal Republic of Germany and S.T. THORNTON, R.A. CECIL and R.L. PARKS Department of Physics+, University of Virginia, Charlottesville, Virginia 22901, USA and Max-Planck-Institut fiir Kernphysik, D-6900 Heidelberg, Federal Republic of Germany Received 24 May 1983 Abstract: Accurate mass measurements for the nuclides “As, “‘As, and ““Ge have been measured. Good agreement has been found for 79As and ‘lAs with the Garvey-Kelson transverse mass relation and with several mass model predictions. The agreement for “Ge is not as satisfactory and presents a challenge for understanding mass values far off the line of stability. NUCLEAR REACTIONS “Se, 64Ni(‘80, ‘“Ne), E = 102 MeV; ‘sSe, %e, “Se, *aSi, 24Mg, E 160(d, 3He), E = 23-24 MeV; measured v(E(“Ne)), a(E(d)), Q. 79As, “‘As, and s”Ge deduced masses. Comparison with mass model predictions. 1. Introduction Little attention has been given to the neutron-rich isotopes of Ge and As. Only recently have attempts been made to measure masses and level schemes for 79-s’Ge and 79-8’A~. We report here the mass excesses of the 80Ge and 79,81As nuclides. The level schemes of these nuclei were recently reported I). We have previously communicated our present mass values of 79*81A~ in a conference proceedings ‘). All three masses have been previously reported 3, by other groups. From nuclear structure considerations, the 80Ge and 79281As nuclei are in an interesting region of deformed nuclei approaching the neutron magic shell number N = 50. Being far away from the P-line of stability, it is useful to measure these masses in order to compare with various models of nuclear mass predictions. Because of the complex interaction of the collective modes and single-particle effects, rapid changes may occur in binding energies, nuclear shapes, level schemes, subshell closures, etc., as the mass changes. The measurement of these masses will help us to understand these effects. ’ Supported in part by the US National Science Foundation. 151