Behaviour of Laser-Produced Plasma in a Uniform Magnetic Field–Plasma Instabilities

A nearly-cylindrical column of laser-produced plasma has been generated successfully in a uniform magnetic field. The radius of the column initially increases and then decreases (bouncing motion). In the vicinity of the outer surface of this plasma column, where there is a steep density gradient with scale length shorter than the local ion Larmor radius, an azimuthal modulation appears in the plasma luminosity. This is indicative of flute-like instability with the azimuthal wave number k ⊥ ∼4×10 3 B 0.8 (in MKSA units). The dispersion equation based upon the linearized Vlasov equation with the local approsimation is derived and the occurrence of the lower-hybrid-drift instability is predicted. Fairly good agreement is found between theory and experiment.