A charge-transfer experiment has been done in which 63-keV ${\mathrm{Ar}}^{7+}$ was incident on sodium in the ground and first excited states. The electron-capture ratio σ(Na(3p))/σ(Na(3s)) was experimentally determined for this system. The charge-capture cross section was observed to increase by a factor of 1.5 for the excited target.

• Received 28 September 1992

DOI:https://doi.org/10.1103/PhysRevA.47.R3499