Analysis of RSAE Radial Phase Variation in DIII-D Discharges

POSTER

Abstract

The radial phase variation of the eigenfunction of reversed shear Alfven eigenmodes (RSAE) depends upon the plasma shape. The eigenfunctions of RSAEs often exhibit radial variations in phase,1 an effect that can be caused by fast-ion gradients,1 symmetry breaking,2 and radial energy flows.3 The phase change at the outer peak of the eigenfunction is measured by an electron cyclotron emission radiometer diagnostic and entered into a database.  The measured phase change correlates more strongly with “gapin” than with any other parameter, with a clear difference between diverted and limited discharges. (“Gapin” is the spacing between the inner wall and the last closed flux surface.) Representative DIII-D cases are analyzed by NOVA-K, MEGA, and FAR3d and compared with the data.

 

1B.J. Tobias et al., Phys. Rev. Lett. 106 (2011) 075003.

2Z.X. Lu et al., Pl. Phys. Cont. Fusion 61 (2019) 044005.

3G.J. Kramer et al., Nucl. Fusion 59 (2019) 094001.

*Supported by DE-FC02-04ER54698 and DE-SC0020337.

Presenters

  • William W Heidbrink

    • University of California, Irvine

Authors

  • William W Heidbrink

    • University of California, Irvine

  • Erik C Hansen

    • UC Irvine

  • Javier Gonzalez Martin

    • University of California, Irvine

  • Michael A Van Zeeland

    • General Atomics - San Diego
    • General Atomics

  • Nikolai Gorelenkov

    • Princeton Plasma Physics Laboratory

  • Gerrit J Kramer

    • Princeton Plasma Physics Laboratory

  • Donald A Spong

    • Oak Ridge National Lab

  • Max E Austin

    • University of Texas at Austin