Highly excited states of atomic potassium in an external electric field

Abstract

The photoionization spectrum of potassium in an external electric field is examined. Detailed studies are made of the strengths, spacing, and polarization dependence of the quasi-bound Stark states lying above E = O. The results are interpreted as the first observation of electric field enhanced collisional depolarization by charged particles. This conclusion is supported by calculations indicating a depolarizing cross section as large as 10-5 cm2 for the conditions of the experiment.