Published online by Cambridge University Press: 09 March 2009
The one-dimensional Lagrangian code MEDUSA has been adapted to model the pressure of laser photons and the transfer of laser light momentum to underdense plasma investigated using the modified code. It is shown for lasers of wavelength ≃ 1μm that the plasma electron density needs to be close to the critical density (1021cm−3) and that the laser intensity needs to be greater than ∼1016Wcm−2 for significant laser momentum transfer to plasma. It was found that small plasmas (scale-length = 1 μm) result in the best ‘signature’ of laser light momentum transfer to plasma (more enhanced expansion velocities) but that the largest momentum transfer is for the largest plasmas considered (scale-length = 100 μm). The formation of suitable underdense plasmas for momentum transfer by a laser pre-pulse onto a foil target is investigated using a two-dimensional Eulerian code.