Development of two directional beam steering ECH/CD launcher for JT-60SA

摘要

Developments of a two directional beam steering electron cyclotron heating/current drive launcher for JT-60SA have been progressed based on a linear motion antenna concept. A full-scale ((similar to)7 m) mock-up of the mirror steering structure with two kinds of bellows structures and an in-vessel support structure has been fabricated and tested in vacuum successfully. The support structure consists of a pair of angular ball bearings made of Si3N4 for rotational motion and a linear guide assembled by a rail and a housing made of non-magnetic stainless steel and Si3N4 balls. Solid lubricant has been used for the linear guide and it results in the improvement of the life time by a factor greater than 10 with respect to the case without lubricant. Considering that the mock-up test results satisfied the requirements for the bellows and support structures (reliable 40 cm linear movement, 10(5) cycles and angular rotation 30 degrees, 10(4) cycles), the final design of the launcher is underway targeting the start of its fabrication.