Laser plasma interactions in hohlraums

Lasers plasma instabilities are an important constraint in X-ray driven inertial confinement fusion. In hohlraums irradiated with 1.06 μm light on the Shiva laser, plasma instabilities were extremely deleterious, driving the program to the use of shorter wavelength light. Excellent coupling has been achieved in hohlraums driven with 0.35 μm light on the Nova laser. Considerable attention is being given to the scaling of this excellent coupling to the larger hohlraums for an ignition target. Various instability control mechanisms such as large plasma wave damping and laser beam incoherence are discussed, as well as scaling experiments to check the instability levels. (author)