Photodetachment of Na{sup {minus}}

Eigenchannel {ital R}-matrix calculation results are presented for the photodetachment partial cross sections of Na{sup {minus}} for energies up to the Na(5p) threshold. The photoelectron angular distribution asymmetry parameter for the process Na{sup {minus}}+{gamma}{r_arrow}Na(3p)+e{sup {minus}} is also presented over the same energy range. Detailed analyses and identifications of {sup 1}P{sup o} resonance structures are presented and compared with corresponding ones in H{sup {minus}} and Li{sup {minus}}. Our results are compared with works of others, including the four-state close-coupling results of Moores and Norcross [Phys. Rev. A {bold 10}, 1646 (1974)], the resonances observed by Johnston and Burrow [Phys. Rev. A {bold 51}, 406 (1995)] in studies of temporary negative ion formation in electron scattering by Na atoms, and the recent relative Na(4s) partial cross-section measurements of G. Haeffler {ital et al.} [following paper, Phys. Rev. A {bold 59}, 3655 (1999)]. {copyright} {ital 1999} {ital The American Physical Society}