Gas jet IF targets

Progress in laser driven inertial confinement fusion is currently hampered by the inefficient coupling of laser energy into the target. Evidence has been suggesting that one or more plasma phenomena are responsible for this. Unfortunately, during a target implosion it is not possible to isolate and independently study all the individual phenomena that occur simultaneously. Gas jet targets, however, offer new experimental options, and are currently contributing to our understanding of implosion dynamics. A gas jet target, a stream of gas exiting from an orifice and freely expanding into vacuum, is a useful representation of the plasma blowoff from a spherically imploding glass target. The density profile of a gas jet is stable in time and is like a snapshot of the rapidly changing density profile of an imploding glass target. This target allows the plasma physicists to probe and study in some detail the interaction of the laser with a particular state of the target which normally is only a transient moment during a target implosion. The development and characterization of gas jet targets will be discussed.