The ITER ECH system is an in-kind procurement consisting of four different types of gyrotrons (from EU, IN, JA and RF), transmission lines (from US) and two types of launchers (from EU and JA). Each subsystem must interface not only with the other but also with the auxiliary systems control and data acquisition computer and with the plasma (in the case of the launchers). The definition and management of interfaces is therefore essential for the system to guarantee performance, availability and reliability. The proper description of each interface boundary is essential for assembly and operation of the entire system as a single unit. In addition, progress has been made in the development of high power, long pulse systems and associated components that have not been integrated into the ITER EC design since the present ITER EC system was essentially specified prior to 2000. The ultimate physics performance and operational reliability in some situations is limited by this old design, which has not taken advantage of the knowledge and experience gained in operating the multi-megawatt ECH systems on present tokamaks and stellarators.The objective of this paper is to review the present ITER ECH system, which includes the power supplies, gyrotrons, transmission lines and launchers. Modifications are proposed which are performance driven and are engineered for reliability and maintainability, whilst reducing complexity and cost. Potential operating scenarios are discussed which require an intelligent and automatic decision making process, for example, directing the EC power to either of the two EC launchers, based on the immediate physics requirements. The interfaces between the subsystems are described and when possible improvements to each interface are proposed.
Design of the electron cyclotron heating system expansion on EAST