Beam-foil Studies of Phosphorus in the Vacuum Ultraviolet

Abstract

We have measured lifetimes for 24 terms in P I-P V using the beam-foil technique in the vacuum UV region. The results have been compared with theoretical calculations and with other experimental values. Several significant discrepancies with earlier results have been found. We present the first experimental lifetimes for 9 terms. Most of our lifetimes can be converted directly into f -values, and we discuss these in relation to trends along isoelectronic sequences. Configuration interaction is found to be important for several transitions. We also suggest a revision of the recently-determined abundance of phosphorus in interstellar clouds, based upon our new f -value for the 1 308 Å multiplet in P II.