Abstract Details

Add files

Progress in turbulent optimization of toroidal configurations

Author: H. E. Mynick
Requested Type: Poster Only
Submitted: 2012-12-07 07:43:27

Co-authors:

Contact Info:
PPPL
Theory Dept, MS-28
Princeton, NJ   08543
USA

Abstract Text:
Progress in turbulent optimization of toroidal configurations
H.E. Mynick
Princeton Plasma Physics Laboratory

A method recently developed[1] for evolving toroidal configurations to ones with reduced turbulent transport is being applied to a wide range of toroidal designs[2-3]. The method uses the STELLOPT optimization code with a theory-based "proxy" figure of merit Q_prox for computational speed to stand in for the averaged heat flux Q_GK from gyrokinetic runs, and the GENE gyrokinetic code for subsequent corroboration. Recent refinements of Q_prox have given STELLOPT access to configurations with Q_GK from GENE reduced by factors larger than obtained earlier, resolved an earlier disparity between Q_GK and Q_prox for evolutions from the W7X quasi-omnigenous (QO) system, and introduced a new geometric quantity (the metric element g^11) in addition to the earlier one (radial curvature) which may be used as a "knob" in reducing the turbulent transport. With the improved Q_prox, STELLOPT has now evolved configurations from QO, quasi-axisymmetric, and quasi-helically symmetric stellarator designs and a typical tokamak with averaged heat flux Q_GK from GENE reduced by a factor of 3-4.

[1]H. Mynick, N. Pomphrey, P. Xanthopoulos, Phys. Rev. Letters 105, 095004 (2010).

[2]H. Mynick, N. Pomphrey, P. Xanthopoulos, Phys. Plasmas 18, 056101 (2011).

[3] H. Mynick, N. Pomphrey, P. Xanthopoulos, B. Faber, M. Lucia, M. Rorvig, 24th IAEA Fusion Energy Conference (San Diego, CA, October, 2012), Paper TH/P2-04.

Characterization: 1.0,1.4

Comments: