Experimental studies of interaction of intense long laser pulse with a laser-created Ta plasma

Characteristics of ions, emitted from the laser produced plasma, were systematically investigated using high power iodine laser system PALS, operating at 3 omega. A Ta target was irradiated perpendicularly with laser pulse energy 150 J. Changing the laser focus position, not only the laser intensity, but also the length (duration) of laser beam interaction with pre-formed plasma is changing. Self-focusing of laser beam in self-created plasma was proved, moreover with longitudinal structure with a period of similar to 200 mu m.