An electrical discharge initiated by a long laser spark

Based on experimental data concerning the control of an electrical discharg e in long air gaps by means of a neodymium laser with a radiation energy of 5-100J per pulse, it is shown that it is possible in principle to stabiliz e an electrical breakdown by a long laser spark. The dense part of the exte nded laser spark can be treated as a shaped electrical leader. It is conclu ded that a discharge in superlong gaps can possibly be controlled in the re gime of successive overfocusing of a laser beam matched with the propagatio n rate of a spark-breakdown leader. (C) 1999 The Optical Society of America .