Recent progress of the development of a long pulse 140GHz ECRH system on EAST

Abstract

A long pulse ECRH system with a goal of 140GHz 4MW 100~1000s has been developed to meet the requirement of steady-state operation on EAST. Gycom gyrotrons are employed in the No.1 and No.3 systems, CPI gyrotrons are used in the No.2 and No.4 systems. The development of the two Gycom gyrotron systems has been finished. The first short pulse EC wave injection has been demonstrated successfully during the EAST 2015 Spring campaign. In the commissioning and operation towards steadystate operation, 0.4MW 100s has been injected to plasma successfully by using the No.1 system, 4.7keV 102s L-mode and 102s H-mode plasma have been achieved on EAST with the help of ECRH. Recently, a longest pulse of 0.55MW 1000s has been obtained based on calorimetric dummy load measurements on the No.3 gyrotron. The No.2 gyrotron also has been installed and partially tested, 500kW 80s has been demonstrated in the dummy load. The remaining No.4 gyrotron will be ready to test in 2018 or 2019. The whole 4MW system will be completed within two years. The 400s fully non-inductive H-mode operation would be expected in the next four years in the condition of fully tungsten diverter on EAST.

Observation of electron-scale turbulence suppression under weak magnetic shear with neon seeding in EAST plasma

“…The maximum plasma current of EAST is 1 MA and the maximum toroidal magnetic field is 3.5 T. EAST can be operated with upper single null (USN), lower single null and double null configurations. Abundant plasma heating systems are available on EAST, including an lower hybrid wave (LHW) system with 2.45 GHz and 4.6 GHz [40], an electron cyclotron resonance heating (ECRH) system which has strong spatial localization of power deposition [41], an ion cyclotron resonance heating system [42] and a neutral beam injection (NBI) system with four beam lines in which two are co-direction and two are contrary direction [43]. These heating methods can also drive the current.…”

Design of real-time power control system for gyrotron

“…The gyrotron is equipped with magnets, magnet power supply, filament power supply, ion pump power supply (titanium pump power supply), collector coil power supply, oil cooling system and other auxiliary systems [3] . The theory of gyrotron beam interaction shows that the output power of the gyrotron is determined by parameters such as cathode voltage, anode voltage, filament power supply, main magnet current, and cathode magnet current.…”

Design and experimental results of a 28 GHz, 400 kW gyrotron for electron cyclotron resonance heating

“…Among these large-scale scientific facilities, some require gyrotrons at high frequencies [9], such as the International Thermonuclear Experimental Reactor (ITER) [15], the stellarator W7-X [16], DEMO [17], DIII-D [18], EAST [19,20] and HL-2A [9,21].…”