TOKAMAK DISCHARGE TEST WITH A FERRITIC FIRST WALL SIMULATING VACUUM VESSEL

摘要

A plasma discharge experiment, measurements and calculations of the magnetic field in the Hitachi tokamak HT-2rnshowed that ferritic steel is available for the vacuum vessel structural material in fusion devices, in spite of itsrnferromagnetism. The HT-2 has a stainless steel SS304 vacuum vessel and F82H plates were added just like a first wall, tornsimulate a ferritic vacuum vessel. The vacuum quality was not degraded. About 1500 discharge tries cleaned up the F82Hrnand normal discharges was obtained. The magnetic field due to the F82H magnetization was small enough that it did notrncause a problem for plasma discharge in the HT-2. Since the field due to the magnetization is expected to be smaller in largerntokamaks than in the HT-2, we concluded that the ferritic steel can be used as a structural material for fusion devices.