Speaker
Prof.
John Sarff
(University of Wisconsin-Madison)
Description
The reversed field pinch (RFP) offers unique capabilities that could be essential to closing gaps to fusion power. The RFP has large plasma current and small toroidal field, with q(r)<1. Two key benefits arise: (1) the possibility for ohmic heating to ignition and (2) minimization of the field strength at the magnets. The material boundary can be made invisible to an inductive electric field, and the first-wall need not accommodate power injection ports or antennas. These features could help achieve a maintainable and reliable fusion power source. This overview summarizes MST results important for the advancement of the RFP as well as for improved understanding of toroidal confinement generally. Evidence for first observations of trapped-electron mode (TEM) turbulence in the RFP is obtained. Short-wavelength density fluctuations exhibit a density-gradient threshold, and GENE modeling predicts unstable TEM’s. Core-localized neutral beam injection stimulates bursty modes with both Alfvenic and EPM scaling. One mode agrees with a new analytic theory for the magnetic-island-induced Alfven eigenmode (MIAE), which conspires with an EPM to affect fast ion transport. At high current the RFP transitions to the quasi-single-helicity (QSH) state. A method to control the locked phase of QSH has been developed using resonant magnetic perturbations (RMP). Runaway electrons that appear without RMP are suppressed. An improved model for simultaneous interactions of multiple tearing modes and error fields has been developed. The RFP’s tearing-relaxation behavior together with well-developed theory and computation create a ripe opportunity for rigorous validation of MHD models. Integrated data analysis (IDA) complements validation by maximizing the information embedded in multiple diagnostics, which is essential for future fusion development steps having limited diagnostics. Using IDA methods, meta-diagnostics that combine charge-exchange recombination spectroscopy, x-ray tomography, and Thomson scattering yield more robust measurements of Z_eff and T_e, critical parameters for MHD. Nonlinear studies using an extended MHD model including drift and two-fluid physics in NIMROD show features similar to MST observations, including a tendency for the MHD and Hall emf terms to oppose each other in Ohm’s law, and opposition of the Maxwell and Reynolds stresses in momentum balance.
| Country or International Organization | United States of America |
|---|---|
| Paper Number | OV/P-5 |
Primary author
Prof.
John Sarff
(University of Wisconsin-Madison)
Co-authors
Dr
Abdulgader Almagri
(University of Wisconsin-Madison)
Dr
Alexander Ivanov
(Budker Institute of Nuclear Physics)
Dr
Ami DuBois
(University of Wisconsin-Madison)
Mr
Andrew Seltzman
(University of Wisconsin-Madison)
Mr
Anthony Xing
(University of Wisconsin-Madison)
Dr
Brett Chapman
(University of Wisconsin-Madison)
Prof.
Carl Sovinec
(University of Wisconsin-Madison)
Dr
Carson Cook
(University of Wisconsin-Madison)
Prof.
Cary Forest
(University of Wisconsin-Madison)
Prof.
Chris Hegna
(University of Wisconsin-Madison)
Dr
Craig Jacobson
(University of Wisconsin-Madison)
Dr
Daniel Den Hartog
(University of Wisconsin-Madison)
Prof.
Darren Craig
(Wheaton College)
Dr
David Brower Brower
(University of California Los Angeles)
Dr
Derek Thuecks
(University of Wisconsin-Madison)
Dr
Diane Demers
(Xantho Technologies, LLC)
Dr
Donald Holly
(University of Wisconsin-Madison)
Dr
Donald Spong
(Oak Ridge National Laboratory)
Dr
Eli Parke
(University of California at Los Angeles)
Mr
Garth Whelan
(University of Wisconsin-Madison)
Prof.
Hillary Stephens
(Pierce College)
Mr
James Duff
(University of Wisconsin-Madison)
Dr
James Titus
(Florida A&M University)
Prof.
Jan Egedal
(University of Wisconsin-Madison)
Dr
Jay Anderson
(University of Wisconsin)
Mr
Jay Johnson
(University of Wisconsin-Madison)
Mr
John Boguski
(University of Wisconsin-Madison)
Dr
John Goetz
(University of Wisconsin-Madison)
Mr
Joseph Triana
(University of Wisconsin-Madison)
Dr
Joshua Reusch
(University of Wisconsin-Madison)
Dr
Joshua Sauppe
(University of Wisconsin-Madison)
Mr
Jungha Kim
(University of Wisconsin-Madison)
Dr
Karsten McCollam
(University of Wisconsin-Madison)
Dr
Liang Lin
(University of California at Los Angeles)
Dr
Lisa Reusch
(University of Wisconsin-Madison)
Lorenzo Frassinetti
(KTH, Royal Institute of Technology)
Mr
Lucas Morton
(University of Wisconsin-Madison)
Mark Nornberg
(University of Wisconsin-Madison)
Dr
Matthew Galante
(University of Wisconsin-Madison)
Dr
Meghan McGarry
(University of Wisconsin-Madison)
Mr
Michael Borchardt
(University of Wisconsin-Madison)
Mr
Mingsheng Tan
(University of Science and Technology of China)
Dr
Moritz Pueschel
(University of Wisconsin-Madison)
Dr
Oliver Schmitz
(University of Wisconsin - Madison, Department of Engineering Physics)
Dr
Paolo Franz
(Consorzio RFX-Associazione EURATOM ENEA sulla fusione)
Mr
Paul Nonn
(University of Wisconsin-Madison)
Prof.
Paul Terry
(University of Wisconsin-Madison)
Prof.
Per Brunsell
(KTH Kungliga Tekniska Högskolan)
Dr
Peter Fimognari
(Xantho Technologies, LLC)
Mr
Philip Bonofiglo
(University of Wisconsin-Madison)
Dr
R.W. (Bob) Harvey
(CompX)
Mr
Richard Fridström
(KTH Royal Institute of Technology)
Mr
Ryan Norval
(University of Wisconsin-Madison)
Dr
Sergey Polosatkin
(BINP)
Ms
Stephanie Kubala
(University of Wisconsin-Madison)
Dr
Stephanie Sears
(University of Wisconsin-Madison)
Dr
Stephano Munaretto
(University of Wisconsin-Madison)
Dr
Steven Hirshman
(Oak Ridge National Laboratory)
Mr
Steven Oliva
(University of Wisconsin-Madison)
Mr
Takashi Nishizawa
(University of Wisconsin-Madison)
Dr
Thomas Crowley
(Xantho Technologies, LLC)
Dr
Vasily Belykh
(Budker Institute of Nuclear Physics)
Dr
Vladimir Davydenko
(Budker Institute of Nuclear Physics)
Dr
Vladimir Mirnov
(University of Wisconsin - Madison)
Dr
Weixing Ding
(UCLA)
Mr
William Capecchi
(University of Wisconsin-Madison)
Dr
Xiande Feng
(University of Wisconsin-Madison)
Mr
Zachary Williams
(University of Wisconsin-Madison)
