Top-down (a) and a poloidal view (b) on the LOS-setup of the FIDA diagnostic at ASDEX Upgrade. The toroidal LOS are indicated in blue color and the poloidal ones are shown in purple. The MSE LOS is plotted in green. The NBI source Q3, which is used as a diagnostic beam, is sketched in orange and the separatrix position is illustrated by red, dashed lines.
Radial resolution of three lines of sight of the FIDA diagnostic, based on the calculated neutral density present along the path of NBI Q3.
Schematic top-down view on the FIDA spectrometer and camera setup.
(a) Measured spectrum of the neon lamp between 655 nm and 668 nm. (b) Central wavelength on the CCD as a function of the channel's vertical position on the chip. A fit to the data with a parabola is shown in red.
Passive spectra from a toroidal LOS (a) and a poloidal LOS (b) that were observed during (black) and after (gray) an ELM crash. In red, the theoretical shape of the D-alpha emission is plotted, demonstrating the presence of Stark broadening of this line.
D2 spectra from a toroidal LOS, measured with (black) and without (gray) fueling from a proximate valve. In orange, tabulated molecular lines 25 are shown that correspond to n = 3 → 2 transitions of the triplet system.
Passive spectra from two toroidal LOS (a) and (c) and two poloidal LOS (b) and (d) in black that were acquired during off-axis NBI heating. In gray, active spectra are plotted that were acquired during the operation of NBI Q3.
Characteristic time-traces of discharge #29578. From top to bottom, the plasma current and magnetic field, the NBI heating power, the electron density, and the ion and electron temperatures are plotted.
Measured spectra on a semi-logarithmic scale from a toroidal LOS (a), a poloidal LOS (b), and the MSE LOS (c). In addition, the theoretical beam, halo, and FIDA components predicted by FIDASIM are plotted.
TRANSP predicted velocity space distribution of fast ions in ASDEX Upgrade generated by NBI Q3 and a second 93 keV heating beam in discharge at 1.05 s.
Synthetic FIDA spectra observed by a toroidal (blue), poloidal (purple), and the MSE (green) LOS for the two artificial fast-ion distributions sketched in Figure 10 in red and orange. (a) Spectra for pitches between 0.8 and 1.0. (b) Spectra for pitches between −0.1 and 0.1.
Weight functions for a (a)–(c) toroidal, (d)–(f) poloidal, and the (g)–(i) MSE LOS for three different wavelength ranges. Depending on the wavelength, the LOS access different parts of the fast-ion velocity space.
Temporal evolution of the FIDA intensities for three LOS and two wavelength ranges (a) and (b).
Radial FIDA intensity profiles from the 7 toroidal LOS (blue) and 7 poloidal (purple) LOS that were connected to the FIDA spectrometer during discharge #29578. The error bars correspond to the fluctuation of the FIDA signal in the analyzed, 8 ms long, time interval.
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