W7-X

W7-X model

Wendelstein 7-X (W7-X) is an experimental stellarator currently being in operation in Greifswald, Germany by the Max-Planck-Institut für Plasmaphysik (IPP). W7-X is an optimized stellarator, i.e. the magnetic field has been tailored to meet several physical optimization criteria.

Parameter	Value	Unit
Major radius, R0:	5.5	m
Minor radius, a:	0.53	m
Plasma volume, V:	30	m3
Non-planar coils:	50
Planar coils:	20
Number of ports:	254
Rotational transform, ι/2π:	5/6-5/4
Magnetic field on axis, B0:	<3	T
Stored energy, W:	600	MJ
Heating power, P:	15-30	MW
Pulse length:	30	min
Machine height:	4.5	m
Machine diameter:	16	m
Machine mass:	725	t

Optimization criteria

• Feasible modular coils
• Good, nested magnetic surfaces
• Good finite-β equilibria
• Good MHD stability
• Small neoclassical transport
• Small bootstrap current
• Good confinement of fast particles

See also

• Wendelstein 7-X

References

• H. Wobig, The theoretical basis of a drift-optimized stellarator reactor, Plasma Phys. Control. Fusion 35 (1993) 903
• J. Nührenberg et al., Trans. Fusion Technology 27 (1995) 71
• C. Nührenberg, Global ideal magnetohydrodynamic stability analysis for the configurational space of Wendelstein 7–X, Phys. Plasmas 3 (1996) 2401
• V. Erckmann et al, The W7-X project: scientific basis and technical realization, Fusion Engineering 6-10 (1997) 40
• M. Wanner and the W7-X Team, Design goals and status of the WENDELSTEIN 7-X project, Plasma Phys. Control. Fusion 42 (2000) 1179
• M. Wanner et al, Design and construction of WENDELSTEIN 7-X, Fusion Engineering and Design 56-57 (2001) 155-162
• M. Wanner et al, Status of WENDELSTEIN 7-X construction, Nucl. Fusion 43 (2003) 416
• M. Wanner and the W7-X Team, Construction and assembly of WENDELSTEIN 7-X, Fusion Engineering and Design 81, 20-22 (2006) 2305-2313
• L. Wegener, Status of Wendelstein 7-X construction, Fusion Engineering and Design 84, 2-6 (2009) 106-112
• H.-S. Bosch et al, Construction of Wendelstein 7-X; Engineering a Steady-State Stellarator, IEEE Trans. Plasma Science 38, 3 (2010) 265
• H.-S. Bosch et al, Technical challenges in the construction of the steady-state stellarator Wendelstein 7-X, Nucl. Fusion 53 (2013) 126001
• D. Clery, Feature: The bizarre reactor that might save nuclear fusion, Science, 21 October 2015
• O. Neubauer et al, Diagnostic setup for investigation of plasma wall interactions at Wendelstein 7-X, Fusion Engineering and Design 96-97 (2015) 891-894
• T. Sunn Pedersen et al, Plans for the first plasma operation of Wendelstein 7-X, Nucl. Fusion 55 (2015) 126001
• M. Krychowiak et al, Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X, Review of Scientific Instruments 87 (2016) 11D304
• R.C. Wolf et al, Major results from the first plasma campaign of the Wendelstein 7-X stellarator, Nucl. Fusion 57 (2017) 102020
• D. Hathiramani et al, Upgrades of edge, divertor and scrape-off layer diagnostics of W7‐X for OP1.2, Fusion Engineering and Design 136A (2018) 304-308
• A. Dinklage et al, Magnetic configuration effects on the Wendelstein 7-X stellarator, Nature Phys 14 (2018) 855–860
• R.C. Wolf et al, Performance of Wendelstein 7-X stellarator plasmas during the first divertor operation phase, Physics of Plasmas 26 (2019) 082504