X-ray preionization of rare-gas-halide lasers

The preionization characteristics of X-rays for self-sustained discharge rare-gas-halide lasers are summarized. X-rays showed features superior to UV for preionization of large volume high-pressure discharge lasers, which was experimentally confirmed. Futhermore, the effect of preionization on laser output was found to depend on the spatial distribution of preionization electron density and discharge electric field. When a uniform electric field area was homogeneously preionized with a collimated X-ray, an electron density of 10⁷cm^-3was found to be sufficient for high energy extraction of a XeCl laser.