Operational boundaries in Alcator C-mod in agreement with predictions of SepOS
04/16/2025
The Separatrix Operational Space (SepOS) model is shown to predict the L-H transition, the L-mode density limit and the ideal magnetohydrodynamic ballooning limit in terms of separatrix parameters for a wide range of discharge parameters in Alcator-C-Mod plasmas. The SepOS model was developed using the ASDEX Upgrade database. Alcator C-mod is smaller, operates at higher magnetic field strengths and at higher densities. The MIT team was able to show that, despite the very different plasma parameters compared to AUG, the operational limits with SepOS are also predicted reliably for Alcator C-mod. This is a major step forward for the SepOS model. The work was recently published in Nuclear Fusion.
Publication on the transition to drift wave turbulence
04/08/2025
The transitional regime of drift-wave turbulence was also investigated in the magnetized plasma column PANTA. In the transition regime, small changes in the magnetic field strength as a control parameter lead to large changes in the correlation times, indicating the existence of a critical point of an underlying continuous non-equilibrium phase transition. This and the spatio-temporal dynamics show similarities with puff splitting, slug-gap splitting and puff jamming.
The work was recently published in Phys. Rev. E.
Oliver Schmitz as our guest
03/19/2025
Prof. Oliver Schmitz from the University of Wisconsin Madison was our guest and took a look at the labs. We will try to intensify our cooperation on helicon plasmas and investigations on the plasma edge at Wendelstein 7-X. We are grateful for the interesting suggestions and look forward to a fruitful collaboration.
Inference of flow shear from reciprocating plasma potential measurements by means of Gaussian process regression
03/14/2025
Takashi Nishizawa shows in his recent publication in Phys. Plasmas how shear flows can be determined from measurements of the reciprocal plasma potential using Gaussian process regression. This is illustrated with the help of gyrofluid simulations carried out by Peter Manz.
Mecklenburg-Vorpommern supports our project to improve selectivity and energy efficiency in CO₂ splitting
03/10/2025
As part of the state's excellence program 'Application-oriented excellence research', top-level research in the state is being funded. The individual project 'PlaCOs - Plasma Carbon Splitting' by Dr. Fahrenkamp has been successful. This project aims to improve the selectivity and energy efficiency of CO₂ splitting. Cooperation with the INP is planned. We will also develop our helicon discharges in the direction of atmospheric pressure.
PhD defence York
03/06/2025
Peter Manz was on the jury of Theodore Gheorghiu's PhD defense. Congratulations to Dr. Gheorghiu on the defense of his great work.
First discharge in VINETA.75
02/19/2025
VINETA is large enough to deliver relevant results, but small enough to carry out research in a timely manner. This is particularly attractive for Bachelor's and Master's theses. This makes it the ideal training machine, and it was used as such before Wendelstein 7-X was commissioned. Some of those sitting in the Wendelstein 7-X control room today learned their trade at VINETA. When Wendelstein 7-X was commissioned in 2015, VINETA was no longer the focus at IPP in Greifswald. VINETA was offered to Prof. Manz as a kind of dowry for his appointment and will now serve as a training experiment at the university.
VINETA moved from IPP Greifswald to the university in spring 2022. We would like to thank Dr. Adrian von Stechow and Dr. Birger Buttenschön from the IPP. Unfortunately, the VINETA could not yet be put into operation due to a lack of electricity and water supply. In the end, it took until October 2024 to connect the power and water supply, after which Dr. Stefan Knauer, Dr. Nils Fahrenkamp and Sebastian Haag were able to get the experiment up and running again in no time at all - a truly impressive achievement. The working group took this as an opportunity to hold an inauguration ceremony for the newly constructed experiment to demonstrate the first official plasma. Similar to the launching of a ship, the experiment was given its new name - VINETA.75.
Physicists from the University of Greifswald, IPP and INP scientists, young students and cooperation partners from the Universities of Stuttgart and Fukuoka were invited to the inauguration of the newly constructed VINETA.75 experiment. At the inauguration, IPP Director Thomas Klinger triggered the symbolic first plasma discharge - in front of some of the invited guests who were able to fit into the cramped laboratory. Prof. Klinger had designed the VINETA experiment during his first years as a professor together with a doctoral student at the University of Greifswald.
Guests from Japan
In February we had guests from Kyushu University in Fukuoka Japan. Donato Di Matteo and Chanho Moon took a look at the rebuilt VINETA.75 and helped with the first measurements.
SepOS - from ASDEX Upgrade to SPARC
02/12/2025
In this recently published article, SepOS predictions are made for SPARC. The paper contains the previously unpublished SepOS databases for ASDEX upgrade for different magnetic field strengths and plasma currents. The minimum of the heating power limit of the L-H transition is analytically derived from SepOS. And the SepOS for SPARC parameters is presented.
Review Paper on SepOS published
01/27/2025
An overview article about the SepOS was published. The SepOS concept has been pedagogically revised to make the concept more accessible. The work is more closely related to the Rogers, Drake and Zeiler (RDZ) model. This paper summarizes the recent developments regarding the turbulent control parameter and the SepOS. The outlook includes many new ideas.
P. Manz, T. Eich, O. Grover ‘How turbulence sets boundaries for tokamak operation’, Reviews of Modern Plasma Physics 9, 5 (2025)
Professor Peter Manz - Max-Planck-Fellow
01/14/2025
Peter Manz, Experimental Plasma Physics Professor at the University of Greifswald, has been appointed a Fellow of the Max Planck Institute for Plasma Physics (IPP) by the President of the Max Planck Society.
https://www.ipp.mpg.de/5482761/max_planck_fellow_manz