Transition From Construction to Operation Phase of the Wendelstein 7-X Stellarator

Abstract

Abstract-Assembly of the superconducting stellarator Wendelstein 7-X is well advanced, and commissioning of the device is being prepared. A first draft of the commissioning tasks has been developed and will be discussed in this paper.

Experience with the commissioning of the superconducting stellarator Wendelstein 7-X

“…As discussed already in [9,10], the commissioning process started with vacuum tests of the cryostat, which includes two different systems:…”

“…In 2012 a Task Force started to detail the commissioning processes [9,10]. In general, our commissioning process for the W7-X is divided into two steps of increasing levels of system integration.…”

“…The sequence of commissioning W7-X can be divided into six phases, which can be treated separately, as they build up a sequence [9]. Only some tasks in this sequence can be performed in parallel, but the main process has to follows a serial sequence: In the summer of 2013, after these processes for the commission of W7-X had been presented to an international workshop of experts, the commissioning group was set up, the formal processes were defined, and the technical detailing of the six phases mentioned above, was started (sequentially).…”

“…First, each of the 7 coils circuits (5 non-planar and 2 planar coil types) will be loaded with currents up to the nominal values, later the whole magnet system will be operated simultaneously, thereby creating the confining magnetic flux surfaces. At this point in time we will measure the flux surfaces simultaneously [9].…”

Preliminary Design of Imaging Bolometer Fields of View for Wendelstein7-X

“…In a three-dimensional (3D) device such as Wendelstein7-X (W7X) [3,4] the twodimensional (2D) images provided by the IRVB are necessary to understand the complicated divertor and x-point radiation patterns. The ten-fold W7X divertor is divided into two sections, designated as the 'low iota' divertor and the 'high iota' divertor, referring to the magnetic configuration under which the divertor flux to those sections is dominant [5].…”