Observation and Quasistatic Analysis of Structure in Microwave Ionization of Highly Excited Helium Atoms

D. R. Mariani; W. van de Water; P. M. Koch; T. Bergeman

doi:10.1103/PhysRevLett.50.1261

Observation and Quasistatic Analysis of Structure in Microwave Ionization of Highly Excited Helium Atoms

D. R. Mariani, W. van de Water, P. M. Koch, and T. Bergeman

Phys. Rev. Lett. 50, 1261 – Published 25 April 1983

Abstract

The ionization of $He [1 s (n ≃ 30) s] {}^{3}S_{1}$ atoms by an oscillating electric field (9.92 GHz) is strongly dependent on the field amplitude. The ionization curves reveal structures which are absent in those for $H (n ≃ 30)$ atoms. The ionization rate does not increase monotonically near threshold and is approximately constant over one or more regions of higher field. A quasistatic model is considered which relates the structure in the ionization curves of He to the occurrence of anticrossings in He Stark states.

Received 3 February 1983

DOI:https://doi.org/10.1103/PhysRevLett.50.1261

Authors & Affiliations

D. R. Mariani

J. W. Gibbs Laboratory, Yale University, New Haven, Connecticut 06511

W. van de Water and P. M. Koch^*

J. W. Gibbs Laboratory, Yale University, New Haven, Connecticut 06511, and Physics Department, State University of New York at Stony Brook, Stony Brook, New York 11794

T. Bergeman