B. C. G. Reman R. O. Dendy T. Akiyama M. Salewski S. C. Chapman J. W. S. Cook H. Igami S. Inagaki K. Saito R. Seki G. S. Yun
During bursty MHD events, transient ion cyclotron emission (ICE) is observed from deuterium plasmas in the Large Helical Device (LHD) heliotron-stellarator. Unusually, the frequencies of the successive ICE spectral peaks are not close to integer multiples of the local cyclotron frequency of an energetic ion population in the likely emitting regi…
Preprint PublishedB. Geiger A. N. Karpushov S. Sharapov R. Akers A. Bock M. Dunne B. Duval M. Fontana L. Giannone J. Hobirk C. Hopf A.S. Jacobsen D. Keeling P. Lauber C. Marini P. ZS. Poloskei M. Salewski O. Sauter P. A. Schneider D. Testa A.J. Van Vuuren M. Willensdorfer TCV Team ASDEX Upgrade Team EUROfusion MST15 Team
The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …
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 PublishedJ.Galdon-Quiroga M.Garcia-Munoz S.Sharapov L.Sanchis-Sanchez L.Chen M.Dunne J.Gonzalez-Martin M.Hoelz A.S.Jacobsen K.G.McClements M.Nocente F.Orain J.F.Rivero-Rodriguez D.A.Ryan M.Salewski P.Schneider A.Snicker W.Suttrop Y.Todo M.A.Van Zeeland E.Viezzer M.Willensdorfer D.Zarzoso F.Zonca The ASDEX Upgrade Team MST1 Team
An edge resonant transport layer has been found to explain many aspects of fast-ion confinement under symmetry breaking 3D edge perturbations, such as edge localized modes (ELMs) and externally applied magnetic perturbations (MPs). Experimental measurements in the ASDEX Upgrade (AUG) tokamak show that fast-ion losses in the presence of symmetry bre…
Preprint PublishedB. Madsen M. Salewski J. Huang A. S. Jacobsen O. Jones K. G. McClements the MAST team
Velocity-space tomography provides a way of diagnosing fast ions in a fusion plasma by combining measurements from multiple instruments. We use a toroidally viewing and a vertically viewing fast-ion D-alpha (FIDA) diagnostic installed on the spherical tokamak MAST (before the upgrade) to perform velocity-space tomography of the fast-ion distributio…
Preprint Published