Dramatic Enhancement of Optical-Field-Ionization Collisional-Excitation X-Ray Lasing by an Optically Preformed Plasma Waveguide

Abstract

Dramatic enhancement of optical-field-ionization collisional-excitation x-ray lasing is achieved by using an optically preformed plasma waveguide. With a 9-mm-long pure krypton plasma waveguide prepared by using the axicon-ignitor-heater scheme, lasing at 32.8 nm is enhanced by 400 folds relative to the case without the plasma waveguide. An output level of $8\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }\text{ }\mathrm{\text{photon}}/\mathrm{\text{shot}}$ is reached at an energy conversion efficiency of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. The same method is used to achieve x-ray lasing in a gas jet for the high-threshold low-gain transition at 46.9 nm in neonlike argon.