Wendelstein 7‐X: An Alternative Route to a Fusion Reactor

Abstract

With the ITER tokamak magnetic confinement fusion is making the decisive step to realize a burning fusion plasma and prepare the basis for a demonstration power plant (DEMO). Despite the advantages of an intrinsically steady state magnetic field and better stability properties, the development of stellarators lags behind by about 1 1/2 device generations, because of the difficulties to realize the desired magnetic field configuration. The goal of the optimized stellarator Wendelstein 7-X is to overcome the principal deficiencies of the stellarator concept and demonstrate its reactor capability, combining sufficiently good thermal and fast ion confinement with reactor relevant β and collisionality under steady state conditions.

Enhancement of helium exhaust by resonant magnetic perturbation fields at LHD and TEXTOR

“…The interpretation of the measurement results on the level of a global, single reservoir particle balance as employed in this paper, however, clearly demonstrates that RMP fields are a powerful control mechanism for helium exhaust. The combination with exhaust schemes like the island divertor at Wendelstein 7X [92,93] is promising as there the magnetic island, which is used in the present study to manipulate the helium household, actually defines the plasma wall interface itself.…”

Equilibrium effects on the structure of island divertor and its impact on the divertor heat flux distribution in Wendelstein 7-X

“…The optimized, quasi-isodynamic stellarator W7-X (major radius R = 5.5 m, minor radius a ∼ 0.55 m and five field periods) finished its first three operational phases both in a limiter configuration (OP1.1) and an island divertor configuration (OP1.2a & OP1.2b) [18][19][20]. The up-coming campaign of W7-X aims to demonstrate the viability of high-performance long-pulse plasma operation [21].…”