Quantification of systematic errors in the electron density and temperature measured with Thomson scattering at W7-X
Plasma Physics
2023-08-10 v4 Instrumentation and Detectors
Abstract
The electron density and temperature profiles measured with Thomson scattering at the stellarator Wendelstein 7-X show features which seem to be unphysical, but so far could not be associated with any source of error considered in the data processing. A detailed Bayesian analysis reveals that errors in the spectral calibration cannot explain the features observed in the profiles. Rather, it seems that small fluctuations in the laser position are sufficient to affect the profile substantially. The impact of these fluctuations depends on the laser position itself, which, in turn, provides a method to find the optimum laser alignment in the future.
Keywords
Cite
@article{arxiv.2111.03562,
title = {Quantification of systematic errors in the electron density and temperature measured with Thomson scattering at W7-X},
author = {Philipp Nelde and Golo Fuchert and Ekkehard Pasch and Marc N. A. Beurskens and Sergey A. Bozhenkov and Kai Jakob Brunner and Udo Höfel and Sehyun Kwak and Jens Meineke and Evan R. Scott and Robert C. Wolf and W7-X team},
journal= {arXiv preprint arXiv:2111.03562},
year = {2023}
}