Abstract
The absorption spectrum of argon in the region 600-80 Å (20-150 eV) has been studied photographically and photoelectrically, using synchrotron light as a background source and a resolution of 0.06 Å. Many resonances have been observed in the photo-ionization continuum, which are caused by electronic excitation to auto-ionizing states of Ar i. In the region between 27 and 40 eV the observed structure is due to two types of electronic excitation: (i) the excitation of a single electron, resulting in the configuration and (ii) the excitation of two of the outer electrons simultaneously, resulting in configurations of the type . Between 44 and 59 eV, weak structures have been observed in the absorption continuum because of the simultaneous excitation of a and a electron, resulting in configurations of the type . All of the observed resonances have been tabulated, and a partial classification has been given. The profiles of the resonances involving states , for , and the two-electron excitation states and , have been studied quantitatively. The values of , , and have been determined for each of these resonances, and the continuum cross section has been measured between 24 and 36 eV.
- Received 21 June 1968
DOI:https://doi.org/10.1103/PhysRev.177.136
©1969 American Physical Society