Abstract

The production of multiply charged ions induced by collisionless multiphoton absorption in rare gas atoms has been investigated using an intense 50 p sec laser pulse. Doubly charged ions are produced in helium and neon with a 1064 nm laser pulse in the 10¹⁴ - 10¹⁵ Wcm^-2 range. Up to Ar³⁺ ions are produced in Ar, Kr⁴⁺ ions in Kr and Xe⁵⁺ ions in Xe with a 1064nm laser pulse in the 10¹³ - 10¹⁴ Wcm^-2 range. The laser intensity dependence of the production of multiply charged ions has been investigated for the five rare gases /1/. At least 146 photons, a value equivalent to 170 eV, have to be absorbed by a Xe atom at 1064 nm to explain the production of Xe⁵⁺ ions. The basic absorption mechanism of so many photons by such multi-electron atoms is not yet well understood.

© 1984 Optical Society of America