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

Bosch, H.‐S.; Bykov, V.; Brakel, R.; Eeten, P. van; Feist, J.‐H.; Gasparotto, M.; Grote, H.; Klinger, T.; Nagel, M.; Naujoks, D.; Neilson, G.H.; Rummel, Thomas; Schacht, J.; Vilbrandt, R.; Wegener, L.; Werner, A.

doi:10.1016/j.fusengdes.2015.05.010

Cited by 21 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first major commissioning step for W7-X [1] concerned the evacuation of the cryostat with the goal to achieve 10 −5 mbar as a prerequisite for starting cool down of the cryostat and magnet system. The evacuation introduces vacuum loads on the OV, PV and ports causing the structure to deform.…”

Section: Cryostat Evacuationmentioning

confidence: 99%

“…Design, manufacturing and assembly of the main structural components have finished and focus is now lying on commissioning of the basic device [1] and manufacturing and assembly of diagnostics and peripheral systems.…”

Section: Introductionmentioning

confidence: 99%

“…In 2014 the W7-X has started commissioning of the basic machine in preparation of achieving first plasma in mid-2015 [1]. This paper focuses on the verification of the global model of the cryostat system (GMCS) using measurements performed during the first commissioning steps.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Features and analyses of W7-X cryostat system FE model

Eeten

Bräuer

Bykov

et al. 2015

Fusion Engineering and Design

View full text Add to dashboard Cite

Please cite this article in press as: P. van Eeten, et al., Features and analyses of W7-X cryostat system FE model, Fusion Eng. Des. (2015), http://dx.a b s t r a c t The Wendelstein 7-X stellarator is presently under construction at the Max-Planck-Institute for Plasma Physics in Greifswald with the goal to verify that a stellarator magnetic confinement concept is a viable option for a fusion power plant.The main components of the W7-X cryostat system are the plasma vessel (PV), outer vessel (OV), ports, thermal insulation, vessel supports and the machine base (MB). The main task of the cryostat system is to provide an insulating vacuum for the cryogenic magnet system while allowing external access to the PV through ports for diagnostic, supply and heating systems.The cryostat is subjected to different types of loads during assembly, maintenance and operation. This ranges from basic weight loads from all installed components to mechanical, vacuum and thermal loads. To predict the behavior of the cryostat in terms of deformations, stresses and support load distribution a finite element (FE) global model has been created called the Global Model of the Cryostat System (GMCS).A complete refurbishment of the GM CS has been done in the last 2 years to prepare the model for future applications. This involved a complete mesh update of the model, an improvement of many model features, an update of the applied operational loads and boundary conditions as well as the creation of automatic post processing procedures.Currently the GMCS is used to support several significant assembly and commissioning steps of W7-X that involve the cryostat system, e.g. the removal of temporary supports beneath the MB, transfer of the PV from temporary to the final supports and evacuation of the cryostat. In the upcoming months the model will be used for further support of the commissioning of W7-X which includes the first evacuation of the PV.

show abstract

Section: Cryostat Evacuationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Features and analyses of W7-X cryostat system FE model

Eeten

Bräuer

Bykov

et al. 2015

Fusion Engineering and Design

View full text Add to dashboard Cite

show abstract

“…It is designed for steady state plasma operation of up to 30 min with 10 MW Electron Cyclotron Resonance Heating (ECRH) power. For physics experiments of up to 10 s duration ion cyclotron resonance (4 MW) and neutral beam injection (20 MW) heating systems are being stepwise installed starting with OP1.2 [1,2]. In future steady state operated fusion power plants, Plasma Wall Interaction (PWI) is expected to play a substantial role.…”

Section: Introductionmentioning

confidence: 99%

Preparation of erosion and deposition investigations on plasma facing components in Wendelstein 7-X

et al. 2017

View full text Add to dashboard Cite

In the Wendelstein 7-X stellarator with its twisted magnetic geometry the investigation of plasma wall interaction processes in 3D plasma configurations is an important research subject. For the upcoming Operation Phase i.e. OP1.2, three different types of material probes have been installed within the plasma vessel for the erosion/deposition investigations in selected areas with largely different expected heat load levels, namely, ≤ 10 MW/m 2 at the Test Divertor Units (TDU), ≤ 500 kW/m 2 at the baffles, heat shields and toroidal closures and ≤100 kW/m 2 at the stainless steel wall panels. These include 18 exchangeable target elements at TDU, about 30000 screw heads at graphite tiles and 44 wafer probes on wall panels, coated with marker layers. The layer thicknesses, surface morphologies and the impurity contents were pre-characterized by different techniques and subjected to various qualification tests. The positions of these probes were fixed based on the strike line locations on the divertor predicted by field line diffusion and EMC3/EIRENE modeling calculations for the OP1.2 plasma configurations and availability of locations on panels in direct view of the plasma. After the first half of the operation phase i.e. OP1.2a the probes will be removed to determine the erosion/deposition pattern by post-mortem analysis and replaced by a new set for the second half of the operation phase, OP1.2b.

show abstract

“…The W7-X is in a preparation to the second phase of operation in Greifswald, Germany by the Max-Planck-Institut für Plasmaphysik (IPP) [3]. A fragment of the W7-X machine is given in Figure 1.…”

Section: Introductionmentioning

confidence: 99%