Plasma dynamics in box of unshielded fast wave antenna

Since an early date ICRF experiments have been conducted with a Faraday shield (FS) placed between antenna and plasma. Positive effects of the FS are accompanied by adverse ones which include suppression of magnetic flux ofthe antenna central conductor and sputtering of heavy ion impurities from the shield surface due to radio frequency sheath effect. After re-evaluation of the role of the Faraday shield, successful operation of an unshielded ICRF antenna was demonstrated on the medium-size tokamak TEXTOR. This work motivates the present study of plasma dynamics in an unshielded antenna box in the time-asymptotic state, which itself complements an earlier consideration of the transient response. (orig.)