Control of plasma parameters in RF negative ion sources

Summary form only given, as follows. A long lifetime neutral beam injector (NBI) system is necessary for heating future fusion plasmas. Therefore negative ion sources for NBI system should be constructed by using high frequency discharge plasmas. A radiofrequency discharge plasma is one of the most promising candidate for long lifetime ion sources. We studied production and control of ECR and RF (i e capacitively coupled plasma.) plasmas by using the magnetic filter method.