Structural Analysis and Manufacturing of HL-2M Vacuum Vessel and Support Structures

The construction of the HL-2M tokamak (an upgraded machine of HL-2A) is in proximity to the finalization. As one of the main components of the HL-2M tokamak device, the vacuum vessel is designed to a D shape double-thin-wall welded sturcture. The whole structure is divided into 20 sectors in the toroidal direction including 4 sectors that are used to compensate for manufacturing and assemble errors during the construction period. Considering to the thermal expansion of the vacuum vessel and the limited space in this tokamak device, there are five support rods which are made of Inconel 718 locating in the midplane of the vacuum vessel. The structural analysis has been performed on magnetic loads induced by a plasma disruption and thermal loads during a plasma discharge. The maximum stress is obtained within allowable stresses of vacuum vessel material Inconel 625, it is concluded that this type of vacuum vessel structure is suitable for HL-2M. Up to now, the manufacturing work of 16 sectors and all the support rods have been finished. The entirely assembly and related text work (dimension measurement, leak detecion and pumping experiment) will be finished before June 2018.