Ionization yield measurement using metal electrodes with a static electric field in ambient air

Abstract

The amount of ionization produced in a laser-matter interaction provides critical information in studying strong field physics and attosecond science. The amount of ionization can be accurately measured in vacuum using a photoelectron/ion spectrometer by counting the number of charged particles. However, an ionization yield measurement in ambient air requires the considerations of post processes such as drift and recombination of charged particles, which may add an unwanted nonlinearity to the measurement. Here we investigate the kinetics of the charged particles after optical field ionization in ambient air under a static bias field. A simple kinetic model is used in which coupled rate equations are numerically solved. The kinetic model explains the recombination loss of the charged particles observed in ionization yield measurements. A condition for the static bias field is derived for an accurate ionization yield measurement.