Stellarator News Past Issues

This archive contains past issues of Stellarator News that were published up to April 2017. Later issues can be found at https://stelnews.info.

Issue 156, April 2017

Confirmation of the magnetic topology of W7-X
The n = 1, m = 2 field error in W7-X has been measured to be less than 1:100,000 and agrees well with that expected from the as-built, as-installed coil geometry. These results were recently published in Nature Communications and are summarized here.

The new era has begun: The first deuterium plasma in LHD on March 7, 2017
The LHD launched its new phase of research with deuterium plasmas on March 7, 2017, after several years of preparation and device upgrades.

Issue 155, December 2016

Power loads to the limiters in the initial W7-X campaign
In the initial campaign of Wendelstein 7-X, the machine was operated in a limiter configuration using up to 4 MW of ECRH power. Power loads to the limiters due to the 3-dimensional topology of the scrapeoff layer were measured and calculated. 

Issue 154, October 2016

Multiregion relaxed MHD — A new approach to an old quandary
Three-dimensional equilibria are essential to properly analyze stellarators. The Stepped-Pressure Equilibrium Code (SPEC) has been developed at PPPL, and as a first step towards predictive capability, SPEC has been verified for stellarator vacuum fields including islands. The next steps to be undertaken are the calculation of stellarator equilibria with finite prescribed current and pressure in free boundary. 

Issue 153, June 2016

Summary of WEGA Operation at IPP Greifswald
WEGA operated as a stellarator in Greifswald to train new plasma scientists and to develop diagnostics and operating scenarios for Wendelstein 7-X (W7-X).

W7-X program and plasma evaluation workshop
A workshop was held in Greifswald at the end of May to discuss initial W7-X results and plans for the next operational phase.

Report on the 15th Coordinated Working Group Meeting
Activities at the 15th CWGM, held in Greifswald from 21–23 March, 2016, are discussed. 

Issue 152, April 2016

First Wendelstein 7-X experimental campaign successfully completed
The first experiments began on 10 December 2015, and were more successful than expected. W7-X exhibited extremely reliable operation and proper interplay between the various technical systems, in particular the cryoplant, the superconducting magnet system, the device control, and the microwave tubes of the ECRH system.

US STELLCON Community Workshop
A workshop was held at MIT on February 16–17 to discuss and define the stellarator design, physics, and research needs of the US program.

In memoriam: Julian Dunlap
Julian was head of the ATF stellarator in the 1980s– early 1990s. 

Issue 151, December 2015

Recent Milestones for Wendelstein 7-X: Commissioning and Operations
Wendelstein 7-X passed rigorous safety tests and has been approved for operation in the middle of December.

20th International Stellarator-Heliotron Workshop
The workshop, hosted by the Max Planck Institute for Plasma Physics, was held 5–9 October 2015, at Greifswald, Germany. There were 163 presentations. 

Issue 150, October 2015

14th Coordinated Working Group Meeting Warsaw, 17–19 June 2015
The 14th CWGM was hosted by the Institute of Plasma Physics and Laser Microfusion. Long-term and short-term joint tasks were coordinated and assigned.

This is the 150th issue of Stellarator News
The Editor wishes to thank the community.

Issue 149, August 2015

Recent Milestones in the Wendelstein 7-X Commissioning
Vacuum leaks were repaired and the W7-X coils were tested individually and together, and everything was in accord with specifications. The flux surfaces were measured and were well formed.

Issue 148, June 2015

Europe and W7-X: An example of European collaboration
EUROfusion was formed in 2014 as a consortium of 29 national European fusion laboratories. It is now implementing a fusion Roadmap that breaks the overall task into eight missions. As the cornerstone experiment of Mission 8, Wendelstein 7-X provides a platform for collaborative activity.

Event Detection Intelligent Camera for real-time plasma diagnostics and control at W7-X
An innovative concept has been developed to deal with the massive amount of data needed to monitor the entire W7-X interior with sub-ms resolution during long pulses and with multiple cameras.

Issue 147, April 2015

Recent milestones in commissioning Wendelstein 7-X
The W7-X superconducting coils have been cooled down to 4 K. Evacuation of the vacuum vessel has started and the leak search is ongoing.

International Workshop on the Strategy for Stellarator/Heliotron Research
This workshop was held 4–6 March, 2015, in Nagoya. The purpose of the workshop was to discuss plans for stellarator/heliotron research with a view toward a DEMO device. Emphasis was placed on free discussion based on the present status of theoretical and experimental research and reactor-relevant design studies, rather than on gaining consensus among participants.

Announcement: 14th Coordinated Working Group Meeting
The 14th meeting will be held in Warsaw, Poland, 17–19 June 2015.