CO2laser‐driven absorption waves in underdense hydrogen

摘要

A 600‐MW CO2laser oscillator has been used to induce breakdown in hydrogen with filling pressures in the range 10–20 Torr. The breakdown region is observed to undergo a transition from an optically thin symmetric expansion at laser fluxes in excess of ∼ 108W/cm2to an optically thick undirectional expansion at laser intensities below this.