Dimensionally similar discharges and energy confinement of the W7-AS stellarator were investigated. The results presented, as well as other confinement properties of the net-current-free stellarator, are different from what is known from tokamaks. As expected from global scaling laws for stellerator confinement, the local transport coefficients of dimensionally similar discharges show a gyro-Bohm-like parameter dependence.

• Received 26 October 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.936