Investigation of very neutron deficient Ru and Rh nuclei with the help of (40Ca;yp+z??) reactions

Abstract

40Ca beams from the Munich tandem and from the Munich heavy ion postaccelerator have been used to produce very neutron deficient Ru and Rh nuclei with58Ni (40Ca,yp+zαγ) reactions. The nuclei92Ru,94Ru and95Rh have been studied with in-beam γ ray spectroscopy consisting of the measurement of excitation functions, γ γ coincidences, γ ray angular distributions and life times with the recoil distance method. The following new level energies, spin parity values and half-lives have been deduced:92Ru: 865.3 keV 2+; 1,855.8 (4+); 2,672.7 (6+); 2,834.6 (8+) 100±14 ns; 3,640.3 (10+), 4,206.1 (12+)94Ru: 2,624.7 (5−) 530 −200 +500 ps; 3,991.7 (10+); 4,197.9 (9−); 4,489.3 (11−) 780±120 ps; 4,717.1 (12+) 35±3ps; 5,568.4 (13−); 5.826.8 (14−); 6,360.3 (14−); 6,614.7 (13+); 7,158.3 (14+); 7,774.1 (15); 8,412.1 (16); 9,042.2 (17)95Rh: 1,350.7 (13/2+); 2,067.2 (17/2+); 2,236.2 (17/2−) 15±5ns; 2,449.0 (21/2+) 2.1±0.3 ns; 3,241.2 (21/2−); 3,724.1 (25/2+); 3.908.9 (25/2−); 4,307.2 (27/2+); 4,457.9; 4,716.9; 5,063.2; 6,797.3; 7,627.4 The residual activities have been studied with multi spectra analysis'. The decay scheme of94Rh(25±2 s) has been established.