Revised and extended analyses of doubly and trebly ionized arsenic: As iii, As iv

Abstract

We photographed the spectrum of arsenic in the 300–1220-A-wavelength region on a 3-m normal-incidence spectrograph, using a sliding spark and a triggered spark source. Earlier analyses of As iii and As iv have been revised and extended. In the As iii spectrum we have established 40 new levels and classified 129 additional lines. In the As iv spectrum we have established 27 new levels and classified 100 additional lines. The parametric least-squares-fitted calculations have been carried out for the first time to our knowledge for these ions, and they satisfactorily interpret the observed spectra.