Experimental Mean Lives for Mn I, II, and III, and Their Implications for a Revised Manganese Solar Abundance

Abstract

A discussion is presented of beam foil mean lives for 9 terms of Mn I, 5 terms of Mn II, and 4 terms of Mn III. Attention is given to the energy loss sustained by the ions in the foil and to the limitations imposed by the finite time resolution of the technique. Transition probabilities derived from these mean lives are compared with those obtained by a variety of experimental and theoretical techniques; generally good agreement was obtained with values previously suggested by Allen, by Martinson et al., by Blackwell and Collins, and by Woodgate. Our values are also used, in conjunction with several curves of growth discussed in the literature and a new branching-ratio measurement, to derive a revised value of the photospheric abundance of manganese given by log N(Mn) = 5.34 ± 0.08.