Abstract. The Helias reactor (HSR) is an upgraded version of the Wendelstein 7-X experiment, which is under construction in the city of Greifswald. Recent studies have been focussed on a 4-period Helias configuration (major radius 18 m, plasma radius 2.0 m, B = 5 T), which presents a more compact option than the five period configuration. Main effort has been focussed on two versions of the the 4-period configuration, one option is the power reactor HSR 4/18 providing at least 3 GW of fusion power and the second option is the ignition experiment HSR 4/18/i aiming at a minimum of fusion power and the demonstratioon of self-sustaining burn. The design criteria of the ignition experiment HSR 4/18/i are the following: The experiment should demonstrate: A safe and reliable route to ignition, self-sustained burn without external heating, steady-state operation during several hundred seconds, reliability of the technical components and tritium breeding in a test blanket. The paper discusses the technical issues of the coil system and the blanket. The plasma will be modelled with a transport code and the ignition conditions will be investigated using current scaling laws of energy confinement.
IAEA 2003