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David Higgins

Position: PhD student

Supervisor: Bogdan Hnat

Project title: Plasma flow and particle transport in 3D Alfven-drift turbulence

Funding: EPSRC, Science and Innovation Grant

Research Interests:

  • Sheath/Interchange Closure in MAST Edge/SOL Plasmas
    Theories of blob transport via j X B radial drift require a current closure for the polodial diamagnetic current that causes the plasma interchange. Limiting models inculde closure via (parallel) sheath curents or via (perpendicular) polarisation current. Via the analysis of the velocities & densities of blobs/filaments in MAST plasmas limits can be potentially placed upon when sheath currents are significant in propagation.
  • Turbulent Particle Flux in MAST Edge/SOL Plasmas
    Using data from Langmuir probes, one is able to construct the (ExB) particle flux from the measured potentials and densities. Simple models that assume bivariate normal distribution in density and velocity with some correlation value reproduce the general shape of the flux distribution. This works well in the edge plasma, however in the SOL it does not describe the tails of the distribution particularly well (indeed density and velocity are not normally distributed in the SOL). Stochastic models that are more general, or indeed based on the SOL physical processes can begin to match the SOL distributions more accurately.

Scripts:

  • idl2dat
    This one takes a .idl file as input to the bash script "idl2dat". It outputs all the variables in the .idl file as a .dat file each, with arrays corrected from the idl export style for compatibility with something like matlab, but sorting the data into a single column (for idl array variables). Thanks to Nicky Chorley for his help and his "columnise" function.
Email: d.c.j.higgins@warwick.ac.uk
Office: PS122
Extension: 73875