TY - JOUR
T1 - Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements
JF - Nuclear Fusion
Y1 - 2012
A1 - Salewski, M.
A1 - Geiger, B.
A1 - Nielsen, S.K.
A1 - Bindslev, H.
A1 - M. García-Muñoz
A1 - Heidbrink, W. W.
A1 - Korsholm, S. B.
A1 - Leipold, F.
A1 - Meo, F.
A1 - Michelsen, P. K.
A1 - Moseev, D.
A1 - Stejner, M.
A1 - Tardini, G.
KW - ALPHA
KW - TOKAMAK
KW - X-RAY TOMOGRAPHY
AB - We compute tomographies of 2D fast-ion velocity distribution functions from synthetic collective Thomson scattering (CTS) and fast-ion D-alpha (FIDA) 1D measurements using a new reconstruction prescription. Contradicting conventional wisdom we demonstrate that one single 1D CTS or FIDA view suffices to compute accurate tomographies of arbitrary 2D functions under idealized conditions. Under simulated experimental conditions, single-view tomographies do not resemble the original fast-ion velocity distribution functions but nevertheless show their coarsest features. For CTS or FIDA systems with many simultaneous views on the same measurement volume, the resemblance improves with the number of available views, even if the resolution in each view is varied inversely proportional to the number of views, so that the total number of measurements in all views is the same. With a realistic four-view system, tomographies of a beam ion velocity distribution function at ASDEX Upgrade reproduce the general shape of the function and the location of the maxima at full and half injection energy of the beam ions. By applying our method to real many-view CTS or FIDA measurements, one could determine tomographies of 2D fast-ion velocity distribution functions experimentally.
VL - 52
SN - 0029-5515
IS - 10
U1 - FP
U2 - PDG
U5 - 2ba49eb1441e838e1b4b1429134d2e12
ER -