Refining a finite difference-based approach to helium transport analysis

POSTER

Abstract

A He transport model based on spatial finite differences has been developed to quantify increases in helium transport observed in an ITER-like tokamak plasma during RMP-ELM suppression*. Due to coarse spatial sampling in this data, in contrast to conventional methods that compare trial solutions of the continuity PDE to data, a discrete finite-difference approximation to this PDE is used.



New work enables this model to be applied with matrix operations, removing human input and greatly improving convergence time. Fits obtain He transport (D, v) profiles, the source’s spatial structure in the plasma edge, the He pump rate, and uncertainties. Pump rates obtained for the Ar-frosted cryopump compare well with earlier work**. This effort aims to simplify transport analysis for application to between shot control-room analysis and potentially also to real-time computation.



*E.T. Hinson et al 2020 Nucl. Fusion 60 054004

**M. M. Menon, et al, J. Vac. Sci. and Tech. A 13, 551 (1995)

*Work supported by US DOE under DE-FC02-04ER54698, DE-SC0013911, DE-SC0020284, DE-SC0022270, DE-AC05-06OR23100, DE-FG02-07ER54917, DE-AC05-00OR22725, and DE-AC04-94AL85000.

Presenters

  • Edward T Hinson

    • University of Wisconsin - Madison

Authors

  • Edward T Hinson

    • University of Wisconsin - Madison

  • Tyler Abrams

    • General Atomics - San Diego
    • General Atomics

  • Igor Bykov

    • General Atomics
    • University of California, San Diego

  • Colin Chrystal

    • General Atomics - San Diego

  • Cami S Collins

    • Oak Ridge National Lab

  • Brian A Grierson

    • General Atomics
    • General Atomics Corp.

  • Carlos A Paz-Soldan

    • Columbia University

  • Oliver Schmitz

    • University of Wisconsin - Madison
    • Department of Engineering Physics, University of Wisconsin, Madison, USA

  • E.A. A Unterberg

    • Oak Ridge National Laboratory
    • Oak Ridge National Lab