Setup of the lithium beam diagnostic on DIII-D with the source (S), the neutralizer (N), and the torus isolation valve (TIV). The beam emission is observed from below through a mirror (M), a fiber bundle (FB), a set of etalon (E), and interference (IF) filters and photomultiplier tubes (PMT). The PMT signals are acquired by the data-acquisition system (DAQ). The polarization is analyzed using two photo-elastic modulators (PEM) and linear polarizer (LP). An Additional linear polarizer (Polarcor) can be inserted into the view remotely. Adapted from Ref. 8 .
Radial profile of the Doppler shifted emission of the Li-I(2s-2p) transition for the 2005 (blue) and 2012 campaigns (red, #149 531 and #149 532). Error bars represent the accuracy of the gaussian fits applied to the measured spectrum. Data points are marked with their channel number.
Measured (solid) and calculated (dashed) levels of circular (CP) and linear (LP) polarization as a function of ellipticity of incident light.
Frequency spectrum with linear polarizer (Polarcor) inserted (red, #149 371) and retracted (black, #149 635) at t = 2700−3700 ms and R = 2.2670 m. The PEM harmonics correlated to the intensity due to linear polarized light (△) and circular polarized light (□) are marked.
Normalized signal variation as a function of integration time during a beam into deuterium gas (BiG, grey) phase prior to discharge 149 635 at t = −180 − (−128) ms for the radial channel at R = 2.2460 m and during the plasma discharge #149 635 at t = 2000−2052 ms for two radial channels at R = 2.2460 m (black) and R = 2.2775 m (red). Dashed lines represent the Poisson noise levels for a given photo-electron electron flux. Vertical lines indicate the integration times for which the normalized variation is four times the Poisson noise level.
Time traces of field line pitch angle and B view of #149 635 at R = 2.2670 m (a) and relative statistical errors of circular polarization (CP), linear polarization (LP), DC level, pitch angle and B view (b).
Measured relative poloidal magnetic field B p /B t as a function of the modeled EFIT prediction during the L-mode startup phase of #149 644. The dashed line indicates identity.
Radial profile of the magnetic field along line of sight B view for shot #149 634 in L-mode (t = 2305 ms, ◯) and H-mode (t = 2905 ms, □). Solid lines represent measured data and dashed lines the kinetic EFIT prediction.
Images of the lithium beam emission at λ = 670.8 nm in the L-mode [(a), t = 1899 ms] and H-mode [(b), t = 2598 ms phase of #150 000.
(a) Electron density field n e (R, t) reconstructed from data from BES using the CRM by Sasaki et al. 24 (#150 000). The position of the separatrix from EFIT is overlayed (black). (b) Electron density time traces n e (t) for two radii in comparison to mapped data from the Thomson Scattering diagnostic.
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