Journal ArticleDOI
Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.
TLDR
The design of the scintillator probe, the new technique used to analyze the data through spectrograms will be described, as well as the diagnosis prospects of this method for ITER.Abstract:
A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].read more
Citations
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Journal ArticleDOI
Physics of Alfvén waves and energetic particles in burning plasmas
Liu Chen,Fulvio Zonca +1 more
TL;DR: In this article, the interactions of these energetic particles with linear and nonlinear Alfve'n waves generated in the magnetized plasma are reviewed, and the interaction of the alpha particles produced in the nuclear reactions is discussed.
Journal ArticleDOI
Measurements and modeling of Alfvén eigenmode induced fast ion transport and loss in DIII-D and ASDEX Upgrade
M. A. Van Zeeland,W. W. Heidbrink,R. K. Fisher,M. Garcia Munoz,G. J. Kramer,D. C. Pace,Roscoe White,S. Aekaeslompolo,Max E Austin,J. E. Boom,I. G. J. Classen,S. da Graca,Benedikt Geiger,M.V. Gorelenkova,N. N. Gorelenkov,A.W. Hyatt,Neville C. Luhmann,M. Maraschek,George McKee,R.A. Moyer,Christopher Muscatello,Raffi Nazikian,Hyeon K. Park,S. E. Sharapov,W. Suttrop,G. Tardini,Benjamin Tobias,Y. B. Zhu,Diii-D +28 more
TL;DR: In this article, neutral beam injection into reversed magnetic shear DIII-D and ASDEX upgrade plasmas produces a variety of Alfvenic activity including toroidicity-induced Alfven eigenmodes (RSAEs) and reversed shear Alfven (RSE) during discharge current ramp phase when incomplete current penetration results in a high central safety factor and increased drive due to multiple higher order resonances.
Journal ArticleDOI
Super-thermal particles in hot plasmas—Kinetic models, numerical solution strategies, and comparison to tokamak experiments
TL;DR: In this article, a more detailed and quantitative understanding of fast-particle-driven instabilities in hot plasmas has been presented, which can be used to diagnose various kinetic features of the plasma modes that are responsible for the transport of energetic particles.
Journal ArticleDOI
Fast-ion D-alpha measurements at ASDEX Upgrade
Benedikt Geiger,M. Garcia-Munoz,W. W. Heidbrink,R. M. McDermott,G. Tardini,R. Dux,R. Fischer,V. Igochine +7 more
TL;DR: In this article, a fast-ion D-alpha (FIDA) diagnostic has been developed for the ASDEX upgrade (AUG) tokamak using 25 toroidally viewing lines of sight and featuring a temporal resolution of 10
Journal ArticleDOI
Scintillator-based diagnostic for fast ion loss measurements on DIII-D.
R. K. Fisher,D. C. Pace,M. Garcia-Munoz,W. W. Heidbrink,Christopher Muscatello,M. A. Van Zeeland,Y. B. Zhu +6 more
TL;DR: Initial DIII-D results showing prompt losses and energetic ion loss due to MHD instabilities are discussed.
References
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Ambrogio Fasoli,C. Gormenzano,Herbert L Berk,Boris Breizman,Sergio Briguglio,D. S. Darrow,Nikolai Gorelenkov,W. W. Heidbrink,A. Jaun,Sergey Konovalov,Raffi Nazikian,J.-M. Noterdaeme,S. E. Sharapov,Kouji Shinohara,Duccio Testa,Kenji Tobita,Yasushi Todo,Gregorio Vlad,Fulvio Zonca +18 more
TL;DR: A review of the progress accomplished since the redaction of the first ITER Physics Basis (1999 Nucl Fusion 39 2137-664) in the field of energetic ion physics and its possible impact on burning plasma regimes is presented in this paper.
Journal ArticleDOI
Basic physics of Alfvén instabilities driven by energetic particles in toroidally confined plasmasa)
TL;DR: Alfven wave instability in toroidally confined plasmas is studied in this paper, where the authors identify three types of Alfven wave instabilities: frequency crossings of counterpropagating waves, extremum of the continuous spectrum, and reversed shear Alfven eigenmode.
Journal ArticleDOI
Absolute light output of scintillators
TL;DR: In this article, the absolute light outputs of BGO, CsI(Tl) and some new Ce-doped crystals have been measured to an accuracy of about /spl plusmn/5% using calibrated XP2020Q photomultipliers and standard S3590.03 and S2740.03 photodiodes.
Journal ArticleDOI
Excitation of the toroidicity-induced shear Alfvén eigenmode by fusion alpha particles in an ignited tokamak
Guoyong Fu,J. W. Van Dam +1 more
TL;DR: In this article, the toroidicity-induced shear Alfven eigenmode was found to be destabilized by fusion alpha particles in an ignited tokamak plasma.
Journal ArticleDOI
Excitation of toroidal Alfvén eigenmodes in TFTR.
K. L. Wong,R. J. Fonck,S. F. Paul,D. Roberts,E.D. Fredrickson,Raffi Nazikian,Hyeon K. Park,M.G. Bell,N. L. Bretz,Robert Budny,Samuel A. Cohen,Gregory W. Hammett,F. C. Jobes,Dale Meade,S. S. Medley,D. Mueller,Yoshio Nagayama,D.K. Owens,E. J. Synakowski +18 more
TL;DR: Deuterium neutral beams with energies up to 110 keV were injected into TFTR (Tokamak Fusion Test Reactor) plasmas at low magnetic field such that the beam injection velocities were comparable to the Alfven velocity.