Existing codes for directly solving for the particle distribution function in laser plasma interaction studies either assume a collisionless plasma or solve for the full Fokker-Planck collision term. The former approach is the basis of an existing code at Warwick (VALIS). The latter approach is computationally expensive and often relies on a spherical harmonic expansion of the distribution function, making the implementation of a laser driver difficult. Here the existing collisionless code is extended by including reduced collision operators based on both the Krook and Fokker-Planck operator. The formulation of a fully conservative velocity-dependent Krook operator that shows agreement classical transport co-efficients in the regimes they are valid. The accuracy of the operator is shown to be improved using a normalisation method to ensure the Krook model yields the same heat flux as the Fokker-Planck model. The Krook model is also shown to be in agreement with full Vlasov-Fokker-Planck simulations of non-local transport. Two forms of a model Fokker-Planck operator are also included as a comparison to other reduced models of collisions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:632880 |
| Date | January 2014 |
| Creators | Fletcher, Daniel |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/63944/ |
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