The Coulomb excitation of a thick 24Mg target was studied with 35Cl ions of 61, 57, and 52 MeV. The absolute cross section and the anisotropy of the angular distribution of the ground state transition from the 1.369-MeV state in 24Mg was measured, and their dependence on B(E2) and the quadrupole moment, Q, of the 1.369-MeV state was calculated. A B(E2) of 24.5 ± 2.2 Weisskopf units (W.u.) was deduced from the line shape of the 1.369-MeV gamma ray observed with a 40 cm3 Ge(Li) detector. The quadrupole moment determined from the anisotropy measurement was Q = −0.38 ± 0.16 b. From the cross-section measurement, Q = −0.47 ± 0.19 b was obtained using B(E2) = 24.5 ± 2.2 W.u. The dependence of this value of Q on B(E2) is discussed.
Lifetime measurements have been made by the Doppler-shift attenuation method for the 1.98-, 3.63-, 3.92-, and 4.45-Mev states in O18 and the 1.28-, 3.34-, and 4.47-Mev states in Ne22, excited by the reactions Li7(C12, pγ)O18 and Li7(O16, pγ)Ne22. Branching ratios have also been measured. The results are tabulated.[Formula: see text]The decay of the 3.92-Mev state in O18 is 93.5% to the 1.98-Mev state and 6.5% to the ground state and of the 4.45-Mev state 74% to the 3.63-Mev state, 26% to the 1.98-Mev state, and less than 2% to the ground state. In Ne22, the ground-state transition from the 4.47-Mev state is less than 2% of the decay to the first excited state.
The observation in 1965 of absorption due to the 18 cm ground-state transition of OH in the direction of Cas A (Weinreb et al., 1963) marked the first occasion on which a molecular cloud was detected at radio wavelengths. However, it was not until the later discovery of high-intensity OH emission (Weaver et al., 1965) that attention turned to nearby galaxies. Unfortunately, searches for OH emission in the Magellanic Clouds (McGee et al., 1965; Radhakrishnan, 1967) and in more distant galaxies (Roberts, 1967) were unsuccessful. The first detection of an OH transition, in absorption against the radio continuum of NGC 253 and 3034 (Weliachew, 1971), went almost unnoticed because the results were unconvincing. However, Whiteoak and Gardner (1973) and Nguyen-Q-Rieu et al. (1976) confirmed the existence of the absorption.
Reduction in the uncertainty of the neutron-capture cross section of 210Bi: Impact of a precise multipolarity measurement of the 2− → 1− main ground-state transition