Effects of different electron pressure on plasma expansion

The Raptor kJ class 1053 nm Nd:Glass laser in the Phoenix laser laboratory at UCLA is used to ablate a dense debris plasma from a carbon or plastic target, which is embedded in a relatively tenuous, uniform, and quiescent ambient magnetized plasma in the Large Plasma Device (LAPD). The LAPD provides a peak plasma density of n i ∼ 1013cm−3, with a background magnetic field that can vary between 200 to 1200G. Debris ions from laser produced plasma expand out conically with super-Alfvenic speed (M A ∼2) to expel the background magnetic field and ambient ions to form a diamagnetic cavity. The interaction of the debris plasma with the ambient plasma and the magnetic field acts as a piston which can create collisionless shocks. Two dimensional hybrid simulations are used to compare to experimental data. The effect of different electron pressure models will be studied and compared to experimental results.