A paper introducing the Wisconsin In Situ Penning (WISP) gauge diagnostic published in AiP journal Review of Scientific Instruments (RSI) has been chosen as an Editor’s Pick.

Dr. Thierry Kremeyer inside the plasma vessel of Wendelstein 7-X
Dr. Thierry Kremeyer inside the plasma vessel of Wendelstein 7-X.

The article titled, Wisconsin In Situ Penning (WISP) gauge: A versatile neutral pressure gauge to measure partial pressures in strong magnetic fields, was written by Dr. Thierry Kremeyer. The Editors felt that the article is noteworthy, and have selected it to be promoted in their journal.

In this paper, a comprehensive overview of the diagnostic development, testing, as well as the implementation at the Wendelstein 7-X (W7-X) stellarator in Greifswald, Germany is presented. This diagnostic enables quantitative measurements of the abundance of light impurities, in particular, helium, and hydrogen isotopes in the neutral reservoir around plasmas. Penning gauges assisted by spectroscopy are a powerful tool for this measurement goal.


The WISP gauge is a miniaturized Penning gauge arrangement, which exploits the ambient magnetic field of magnetic confinement fusion experiments to establish the Penning discharge. Then, in situ spectroscopy is conducted to separate the fractional neutral pressures of hydrogen, helium, and other impurities like nitrogen, argon, and neon. The tool developed has general applicability for fusion and plasma devices for a multitude of applications and is being discussed for implementation on a variety of facilities worldwide.

*This work was funded by the Department of Energy under Grant No. DE-SC0014210 for collaborative research on large-scale sellarator devices. The operation of the MDPX device was funded by the Department of Energy under Award No. DE-SC0019176, the NSF-DOE Partnership Program in Basic Plasma Science and Engineering (Grant No. PHY-1613087/DE-SC0016330), and the NSF-EPSCoR program (Grant No. OIA-1655280). The MDPX device was originally designed and built with funding from the NSF-MRI program (Grant No. NSF-1126067).

— News: 04-15-2020