Design of Electron Cyclotron Resonance Heating protection components for first plasma operations in ITER

摘要

The ITER first plasma operations will occur with no full blanket and divertor components installed. Machine protection is required and First Plasma Protection Components (FPPC) have been designed to shelter the vacuum vessel and other components from the plasma itself and from high power Electron Cyclotron Resonance Heating (ECRH) foreseen for first plasma breakdown. ECRH protection components will be installed to protect in-vessel structures from direct and stray radiation as EC beams will be used for plasma breakdown. This paper is focused on the design of these components including dedicated mirrors to shape and redirect the beams to the EC resonance location in the magnetic field null region and then into a beam dump located in an equatorial port, where exceeding EC radiation will be trapped and dumped. Two mirrors and one grating mirror have been designed to provide the required shaping and directions for the beams coming from the upper launcher towards EC resonance and dump. The beam dump consists of five large plates affixed in an equatorial port. Guidelines that drove the design of the quasi-optical system, characteristics of the mirrors, resulting launched beams and concept developed for the beam dump will be here described.