Boring of a channel in a thermonuclear target plasma by ultrahigh-intensity laser radiation

A two-dimensional hydrodynamic model is proposed for the interaction of laser radiation of ~10¹⁸ – 10²¹ W cm^–2 intensity with an overdense plasma. The model can be used to carry out numerical calculations 4 – 5 orders faster than by the ‘particle-in-cell&squo; method. It is shown that a channel of L~100 μm depth, sufficient to ignite a thermonuclear reaction, can be bored in a plasma of ~10²² cm^–3 density. Such channel boring is accompanied by generation of shock density pulses the evolution of which is essentially two-dimensional. For a given laser pulse energy, there is a specific intensity which maximises the channel depth.