Intense radiation impinging on a plasma near the critical density may be absorbed by exciting electrostatic plasma waves. In inhomogeneous plasmas these oscillations convect out of the interaction region to lower densities where the waves have lower phase velocities. Electrons whose velocity is not much greater than the thermal velocity then absorb the wave. In this process, a very few highly energetic electrons are produced. We present theory and simulation for the absorption of these waves in an inhomogeneous plasma.

• Received 17 July 1974

DOI:https://doi.org/10.1103/PhysRevLett.33.953