First Results from an Event Synchronized -- High Repetition Thomson Scattering System at Wendelstein 7-X
Abstract
The Wendelstein 7-X (W7-X) Thomson scattering (TS) diagnostic was upgraded to transiently achieve kilohertz sampling rates combined with adjustable measuring times. The existing Nd:YAG lasers are employed to repetitively emit "bursts", i.e. multiple laser pulses in a short time interval. Appropriately timing burst in the three available lasers, up to twelve evenly spaced consecutive measurements per burst are possible. The pulse-to-pulse increment within a burst can be tuned from 2 ms to 33.3 ms (500 kHz - 30 Hz). Additionally, an event trigger system was developed to synchronize the burst Thomson scattering measurements to plasma events. Exemplary, a case of fast electron density and temperature evolution after cryogenic H2 pellet injection is presented in order to demonstrate the capabilities of the method.
Cite
@article{arxiv.1907.00492,
title = {First Results from an Event Synchronized -- High Repetition Thomson Scattering System at Wendelstein 7-X},
author = {Hannes Damm and Ekkehard Pasch and Andreas Dinklage and Jürgen Baldzuhn and Sergey Bozhenkov and Kai Jakob Brunner and Florian Effenberg and Golo Fuchert and Joachim Geiger and Jeffrey Harris and Jens Knauer and Petra Kornejew and Thierry Kremeyer and Maciej Krychowiak and Jonathan Schilling and Oliver Schmitz and Evan Scott and Victoria Winters and the Wendelstein 7-X Team},
journal= {arXiv preprint arXiv:1907.00492},
year = {2020}
}
Comments
11 pages, 5 figures, To be published as proceeding to the 3rd European Conference on Plasma Diagnostics 2019 in Lisbon in the Proceedings Section of the Journal of Instrumentation (JINST)