1. The Design of KSTAR FM reflectometer Seong-Heon Seo National Fusion Research Institute (NFRI)

2. Contents KSTAR Design Schedule

3. KSTAR Tokamak R=1.8 m, a = 0.5 m PF and TF (B T =3.5 T) Coils = Nb 3 Sn I P = 2 MA, 5 min Bad accessibility

4. First Plasma in KSTAR B T = 1.5 T 2 nd Harmonic ECH preionization (84 GHz, 300 kW) Plasma current ~ 100 kA, 0.7 s Magnetic Diagnostics Interferometer (1 ch) ECE (8 ch) H α, Filter Scope CCD Camera (1 kHz)

5. 2 nd Campaign (2009. 9) B T = 3.0 T Plasma current ~ 300 kA, 2 s Fundamental Harmonic ECH preionization (84 GHz, 500 kW) Magnetic Diagnostics Reflectometer (2 ch, Q and V Band) ECE (32 ch) Bolometer X-ray Crystal Spectroscopy (XCS) Operation Parameter New Diagnostics

6. Frequency Selection Plasma type Low field High field Case ICase II n 0 (x10 14 cm -3 )0.20.711.68 B 0 (T)1.53.5 f x_c f ce 2f ce f pe Plasma type Low fieldHigh field Case ICase II Wave modeOXOXOX Frequency range of probing signals [GHz] 0-3333-660-7575-1500-11877-153 Max. accessible position r of cutoff layer (cm) 217183180143180212

7. Q and V Band Reflectometer

8. Q Band (33-50 GHz) Mixer, MQ-U SpaceK Labs Low pass filter LPF1-43-9 SpaceK Labs 25 dB Low pass filter FLP-22-R0000 Militech 40 dB Transition TWT-28-R22R0 Militech Frequency multiplier AQ-4XW-10 SpaceK Labs

9. V Band (50-75 GHz) Mixer, MV-U SpaceK Labs Low pass filter LPF1-62-9 SpaceK Labs 25 dB Low pass filter FLP-15-R0000 Militech 40 dB Transition TWT-28-R15R0 Militech Frequency multiplier AMC-15-RFH00 Militech

10. Antenna design

12. Diagnostics on G-port 1.Interferometer (2008) --> FIR on H-port 2.Reflectometer (2009) 3.MIR (2012) POSTEC  TEXTOR 5 frequencies

13. Interferometer in G-port

14. Antenna of Interferometer

15. G Port

16. Antenna design

17. Engineering Design

18. DETAIL VIEW

21. Frequency Selection Plasma type Low field High field Case ICase II n 0 (x10 14 cm -3 )0.20.711.68 B 0 (T)1.53.5 f x_c f ce 2f ce f pe Plasma type Low fieldHigh field Case ICase II Wave modeOXOXOX Frequency range of probing signals [GHz] 0-3333-660-7575-1500-11877-153 Max. accessible position r of cutoff layer (cm) 217183180143180212

22. W and D Band (B t = 3.5 T) Too expensive

23. Summary and Schedule 2 nd campaign: - Q (33-50 GHz) and V (50-75 GHz) Band in X-mode - B T = 1.5 T 3 rd campaign: - B T = 3.0 T - W Band (75-110 GHz) in X-mode D BandQ and V Band in O-mode Square waveguide + Twister Cross Polarization