J.F. Rivero-Rodriguez S. Sharapov K. McClements M. Garcia-Muñoz N. Crocker M. Dreval D. Dunai N. Fil M. Fitzgerald J. Galdon-Quiroga C. Michael D. Ryan L. Velarde the MAST-U Team
Due to their relatively higher Vbeam/VAlvén ratio, spherical tokamaks are ideal to investigate high-frequency modes such as Compressional Alfvén Eigenmodes (CAEs) and Global Alfvén Eigenmodes (GAEs), and so they have been previously studied in MAST [1, 2]. Besides, the recently installed scintillator-based Fast-Ion Loss …
PreprintW.W. Heidbrink A. Garcia W. Boeglin M. Salewski
The weight function W(X) is a diagnostic sensitivity to phase-space variables X that relates the measured signal C to the distribution function F(X) through the equation C = ∫ W(X)F(X)dX. In the present work, an algorithm to calculate W for a diagnostic that measures 3 MeV protons produced in d(d,p)t fusion reactions between a fast ion and a th…
Preprint PublishedK.G. McClements R. D’Inca R.O. Dendy L. Carbajal S.C. Chapman J.W.S. Cook R.W. Harvey W.W. Heidbrink S.D. Pinches
The detection of fast particle-driven waves in the ion cyclotron frequency range (ion cyclotron emission or ICE) could provide a passive, non-invasive diagnostic of confined and escaping fast particles (fusion a-particles and beam ions) in ITER, and would be compatible with the high radiation environment of deuterium–tritium plasmas in that devic…
Preprint PublishedI.T. Chapman R.J. La Haye R.J. Buttery W.W. Heidbrink G.L. Jackson C.M. Muscatello C.C. Petty R.I. Pinsker B.J. Tobias F. Turco
Sawtooth control using electron cyclotron current drive (ECCD) has been demonstrated in ITER-like plasmas with a large fast ion fraction, wide q = 1 radius and long uncontrolled sawtooth period in DIII-D. The sawtooth period is minimized when the ECCD resonance is just inside the q = 1 surface. Sawtooth destabilization using driven current inside q…
PublishedM. Okabayashi G. Matsunaga J.S. Degrassie W.W. Heidbrink Y. In Y.Q. Liu H. Reimerdes W.M. Solomon E.J. Strait M. Takechi N. Asakura R.V. Budny G.L. Jackson J.M. Hanson R. J. La Haye M.J. Lanctot J. Manickam K. Shinohara Y.B. Zhu
An energetic-particle (EP)-driven “off-axis-fishbone-like mode (OFM)” often triggers a resistive wall mode (RWM) in JT-60U and DIII-D devices, preventing long-duration high-b N discharges. In these experiments, the EPs are energetic ions (70–85 keV) injected by neutral beams to produce high-pressure plasmas. EP-driven bursting events reduce t…
PublishedM.A. Van Zeeland W.W. Heidbrink R.K. Fisher M. García Muñoz, G.J. Kramer D.C. Pace R.B. White S. Aekaeslompolo M.E. Austin J.E. Boom I.G.J. Classen S. Da Graça B. Geiger M. Gorelenkova N. N. Gorelenkov A. W. Hyatt N. Luhmann M. Maraschek G. R. McKee R. A. Moyer C. M. Muscatello R. Nazikian H. Park S. Sharapov W. Suttrop G. Tardini B. J. Tobias Y. B. Zhu DIII-D and ASDEX Upgrade Teams
Neutral beam injection into reversed magnetic shear DIII-D and ASDEX Upgrade plasmas produces a variety of Alfvénic activity including toroidicity-induced Alfvén eigenmodes and reversed shear Alfvén eigenmodes (RSAEs). These modes are studied during the discharge current ramp phase when incomplete current penetration results in a high central sa…
Published