Synthetic Doppler spectroscopy and curvilinear camera diagnostics in the ERO code

Abstract

We present a set of new synthetic diagnostics, recently implemented in the ERO code, that were developed to facilitate direct comparisons between experiments and modelling of tokamak scrape-off-layer plasmas. The diagnostics calculate the spectroscopic Doppler shift and Doppler broadening of impurity lines of interest for any line of sight, as well as generate camera images from arbitrary viewing angles allowing for curvilinear (e.g. wide angle or fisheye) lenses. The synthetic camera diagnostics can either replicate the distortions caused by curvilinear lenses, or alternatively, create a rectilinear synthetic camera image and correct the curvilinear distortions in the experimental image. Comparison to experimental data is presented.

Nitrogen As A Spectroscopic Tracer For Measuring Plasma Flows In The High-Field Side Sol Of Asdex Upgrade

“…More recently, N has been used to replace C as a spectroscopic tracer in Doppler spectroscopy studies. N is already employed as a seeding gas in ASDEX Upgrade and various other tokamaks and is a more tolerated impurity, as it does not form similar co-deposited layers as C. Furthermore, simulations with the synthetic Doppler spectroscopy diagnostics [4] in the ERO code have shown similar radial impurity flow profiles with N 2 and CH 4 injections, suggesting equal applicability of N and C in flow measurements [5].…”