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Recent progress on the development of a high power 170 GHz gyrotron obtained in Japan Atomic Energy Agency (JAEA) is presented. Firstly, the repetitive operation of 800 kW/600 s with an interval of 20-30 min was performed. The electrical efficiency was 52-57% with the depressed collector. The 72 shots of 88 shots was very stable 600 s oscillation. No damage was found on the gyrotron by this test....
This paper reviews the design and functionality of the 24 MW 170 GHz electron cyclotron heating and current drive system being planned for the ITER Tokamak. The sub-systems (power supplies, gyrotrons, transmission lines and launcher antennas) are described based on present day technologies, while on-going R&D provides component and sub-system testing with the possibility of increasing the reliability...
The effect of the stray magnetic field to the gyrotron collector is analyzed. The analysis includes the stray magnetic field from the adjacent gyrotrons and tokamak. In order to avoid the effect of the stray magnetic field from the adjacent gyrotrons, the minimum distance between the gyrotrons is estimated as 4 m. The effect of the stray magnetic field from tokamak on gyrotron collector (~100 m from...
Recent progresses in gyrotron development and related technologies are presented. The gyrotron demonstrated ITER relevant parameters at 170 GHz (1 MW, 800 s, 55 %), and proved a reliability with long operation period. Recently, one hour operation was obtained at 0.8 MW with the efficiency of 57 %, and total output energy of 190 GJ was recorded with 2 years operation. On the other hand, a power increase...
A 1 MW 170 GHz long pulse gyrotron is required for a power source of the electron cyclotron heating and current drive (EC H&CD) system on ITER (International Thermonuclear Experimental Reactor). In the ITER gyrotron development of JAEA (Japan Atomic Energy Agency), a stable 1 MW 170 GHz oscillation has been achieved at CW-relevant pulse duration (800 s), which is a twice of burning time of ITER...
For the plasma engineering of ITER, EC launchers will be used at the mid and top port levels. The EU is preparing the procurement of the upper port plug and JA the procurement of the equatorial. Part of these studies is to verify the window design and to work out, whether a concept is available for both launchers. To this goal, first experiments with low and high power mm-waves are performed and will...
An injection antenna, so-called launcher, of millimeter wave power to plasma for the ITER (International Thermonuclear Experimental Reactor) has been designed. Two kinds of the ITER launcher, "Equatorial" and "Upper" are required and JAEA has been designing the former and developing its components. The mm-wave transmission section of the equatorial launcher originally consists...
The launcher of a high power millimeter wave is designed for electron cyclotron heating system of ITER plasma. The quasi-optical system was adopted for a transmission lines in the launcher, which simplify the configuration largely comparing with the reference design of the waveguide arrays, and that the heat load was reduced by less than half. On the high power experiment with transmission line of...
A significant upgrade to the 110 GHz DIII-D ECH system was begun in 2005. Two short pulse (< 2 s) GYCOM gyrotrons were replaced by CPI diode gyrotrons having acceptance parameters of 1.0 MW, 5 s and designed pulse length of 10 s. In addition, a CPI gyrotron with depressed collector, which has demonstrated 1.3 MW for short pulses, was installed and is being tested. Two CPI gyrotrons, which have...
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