5-9 September 2016
Prague Congress Centre
Europe/Prague timezone

P2.032 Development of 4-MW KSTAR LHCD system

6 Sep 2016, 14:20
1h 40m
Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Foyer 2A (2nd floor), 3A (3rd floor)

Prague Congress Centre

5. května 65, Prague, Czech Republic
Board: 32
Poster B. Plasma Heating and Current Drive P2 Poster session

Speaker

Jeehyun Kim (Heating and current drive team)

Description

The KSTAR LHCD system is to be upgraded for RF power up to 4 MW in 2020. The basic configuration of the system is composed of eight 5-GHz 500-kW CW klystrons, low-loss transmission line with oversized circular waveguide, and PAM launcher for the mid-plane injection. An off mid-plane injection near the upper diverter is also under consideration. A preliminary study based on a mid-plane PAM launcher will be presented in this paper. The transmission line will be oversized circular waveguides propagating in TE11 or TE01 modes. For TE11 mode, it is easy to design a mode converter, but the polarization rotation can be a problem. On the other hand, TE01 mode has circular electric field with no polarization and extremely low-loss in highly oversized waveguides, but the mode converter is complicated. Two types of TE01 mode converters were designed using HFSS. One is a serpentine type converting TE11circular-to-TE01circular mode. The diameter and total length of the mode conversion region is 80 and 462.8 mm, respectively. The conversion efficiency is 98.7%. The other type has side wall injections of rectangular to circular waveguide and has high efficiency of 99.2%. Mock-ups are under construction. Basic structure of the PAM is similar to that of Tore Supra. The RF power divided into six in poloidal by 3-dB hybrid-splitter followed by TE10-to-TE30 mode converter and then four in toroidal direction by multijunction. Dimension of the active and passive waveguide is 58mm x 7 mm with 2-mm septum for n//=2.5. HFSS calculation showed that the designed multijunction has S11<-34 dB, S21 ~ -6.02+/-0.02 dB, phase shift between adjacent port ~ 90+/-0.8 degree. Detailed RF design of 3-dB hybrid-splitter, TE10-to-TE30 mode converter and multijunction will be illustrated. Spectrum and basic characteristics for grill, FAM, and PAM type antenna were calculated and compared using the ALOHA code.

Co-authors

Haejin Kim (Heating and current drive team, National Fusion Research Institute(NFRI), DAEJEON, South Korea) Jeehyun Kim (Heating and current drive team, National Fusion Research Institute(NFRI), DAEJEON, South Korea) Jinhyun Jeong (Heating and current drive team, National Fusion Research Institute(NFRI), DAEJEON, South Korea) Jongwon Han (Heating and current drive team, National Fusion Research Institute(NFRI), DAEJEON, South Korea) Julien Hillairet (CEA, IRFM, F-13108, Saint-Paul-lez-Durance, France) Lena Delpech (CEA, IRFM, F-13108, Saint-Paul-lez-Durance, France) Moohyun Cho (POSTECH, Pohang, Gyeongbuk, South Korea) Sonjong Wang (Heating and current drive team, National Fusion Research Institute(NFRI), DAEJEON, South Korea) Taesik Seong (POSTECH, Pohang, Gyeongbuk, South Korea) Won Namkung (POSTECH, Pohang, Gyeongbuk, South Korea)

Presentation Materials

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