Calculation of the photodetachment cross section for Al{sup {minus}}

The authors present an eigenchannel R-matrix calculation for photodetachment of Al{sup {minus}} (3s{sup 2}3p{sup 2}{sup 3}P) below the 3s{sup 2}4s ({sup 2}S) threshold for Al. They make the approximation that, for the energies of interest, Al{sup {minus}} may be treated as a quasi-two electron system. A strong doubly-excited state resonance is found below the 3s{sup 2}4s ({sup 2}S) threshold, with primarily 4s4p character. Their results agree well with the resonance structure observed in a recent experiment.