Simulation results for inhomogeneous plasma decay instabilities

The results are reported of simulations on a number of models of modification to the canonical inhomogeneous (in x) coupled wave model (uniform coupling amplitude γ and mismatch wave vector gradient k'). It is concluded that γ-1|d2γ/dx2|=l-2sub(γ) which must be above a minimum value for instability, and suggested that a similar curvature criterion may well apply for non-uniform k'(x) with uniform γ. The transition between γ slabs and previous smooth humped γ forms is bridged using a hyper-Lorentzian γ=γ0(1+(x2/l2sub(γ))sup(m))-1. (author)