Coulomb excitation of Ge 74 and Ge 76

Abstract

Deuterons and protons with energies from 3.5 to 4.0 MeV were used to excite the 598-keV level in Ge 74 and the 564-keV in Ge 76. The scattered particles were studied at angles from 75° to 150° with a magnetic analyzer by using photographic plate detection. The applicability of Coulomb excitation theory in this region of atomic number and incident energy was tested by measuring the energy dependence of the deutron excitation cross sections for both nuclei, the angular distribution of inelastically scattered deutrons for Ge 74 and the ratios of the deuteron to the proton excitation cross section. These data indicate that Coulomb excitation theory may be applied for deuterons of less than 3.5 MeV and protons of less than 4.0 MeV. The values of the reduced transition probability, B( E2), of Ge 74 and Ge 76 are 0.32 ± 0.03 and 0.29 ± 0.03 respectively. The B( E) value derived from 4.0-MeV deutron data for Ge 74 was 30% higher than the above value. Part of this discrepancy may be due to departures from Rutherford scattering of the elastically scattered deuterons, as Rutherford scattering was assumed in deriving the inelastic cross sections.