1. 1 July 27 2009 M. Kwon and the KSTAR Team National Fusion Research Institute

2. 2 Outline Introduction Operation result in 2008 Operation plan for 2009-2010 Longterm Plan KSTAR Collaboration Summary

3. 3 KSTAR objectives and parameters To develop a steady-state capable advanced superconducting tokamak To establish the scientific and technological base for an attractive fusion reactor as a future energy source Major radius, R 0 Minor radius, a Elongation,  Triangularity,  Plasma volume Plasma surface area Plasma cross section Plasma shape Plasma current, I P Toroidal field, B 0 Pulse length  N Plasma fuel Superconductor Auxiliary heating /CD Cryogenic PARAMETERS 1.8 m 0.5 m 2.0 0.8 17.8 m 3 56 m 2 1.6 m 2 DN, SN 2.0 MA 3.5 T 300 s 5.0 H, D-D Nb 3 Sn, NbTi ~ 28 MW 9 kW @4.5K KSTAR 6.2 m 2.0 m 1.7 0.33 830 m 3 680 m 2 22 m 2 SN 15 (17) MA 5.3 T 400 s 1.8 (2.5)* H, D-T Nb 3 Sn, NbTi 73 (110) MW ITER * M. Shimada, et al., Nuclear Fusion, vol. 47, pp. s1 (2007) KSTAR & ITER KSTAR Parameters KSTAR mission

4. 4 Status of the KSTAR tokamak in 2008 KSTAR tokamak Helium distribution system Supercritical, 4.5K, 600 g/s Helium distribution system Supercritical, 4.5K, 600 g/s Vacuum pumping system VV : 42,400 l/s, Cryostat : 36,900 l/s Vacuum pumping system VV : 42,400 l/s, Cryostat : 36,900 l/s ICRH 30~60MHz, 2 MW, 300s ICRH 30~60MHz, 2 MW, 300s ECH 84GHz, 500kW, 2s ECH 84GHz, 500kW, 2s TV ECE Visible spectroscopy HH Filterscope mm-wave interferometer Movable hall probe

5. 5 Status of the KSTAR tokamak July 10, 2009 New Deck for Movable Prove and XCS New Deck for Movable Prove and XCS

6. 6 Minimum in-vessel components were installed for the first plasma. In-vessel components 2008 ICRH antenna ECH antenna Movable hall probe Inboard limiter Poloidal limiter Glow discharge, Gas injection Magnetic Diagnostics Rogowski coils Vessel curent monitor Diamagnetic loop Flux loop Magnetic probes Hall probes Magnetic Diagnostics Rogowski coils Vessel curent monitor Diamagnetic loop Flux loop Magnetic probes Hall probes Optical Diagnostics Visible camera H  Visible spectroscopy Filterscope ECE mm-wave interferometer Optical Diagnostics Visible camera H  Visible spectroscopy Filterscope ECE mm-wave interferometer

7. 7 Most of Magnetic Diagnostics, Full scope of Inboard Limiter In-vessel components 2009 Inboard limiter Inboard Limiter Boundary

8. 8 In-Vessel Component 1 2 2 3 5 4 6 7 1 Inboard Limiter (2009) 2 Divertor (for double null, 20 sec, 2010) 3 Passive Stabilizer (2010) 4 Poloidal Limiter (2010) 5 In-vessel control coil (2010) 6 NB armor (NBI-1, Port L, 2010) 7 In-vessel Cryopump (2010 ~ 2011)

9. 9 Upgrade Sequence of In-Vessel Component 9 1 234 5 6 7 8 Partial Installation of the Inboard Limiter Full Installation of the Inboard Limiter Installation of the IVCC Installation of the Divertor System Installation of the NB Armor Installation of the Passive Stabilizer Installation of the Poloidal Limiter Upgrade for 300s

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11. 11 Startup scenarios Startup scenarios were prepared considering the limited capacity of power supply. Compared between conventional & dipole like start up scenarios ECH pre-ionization 2nd harmonic ECH pre-ionization was achieved at 1.5 T reduced TF field. Due to ECH pre-ionization, required loop voltage could be lowered to about 2 V. 1 st harmonic ECH pre-ionization at 3.0 T is planned in 2009. Startup scenarios and ECH pre-ionization worked well. Plasma discharge Startup scenario Shot 558 TF = 13.3kA (1.5 T @ 1.6 m) ECH = 84 GHz, 500kW, 50ms, Shot 977 TF = 14 kA (1.5 T @ 1.7 m) ECH : perpendicular launch ECH pre-ionization test under TF field only ECH pre-ionization test at dipole-like field configuration

12. 12 KSTAR succeeded achieving reproducible tokamak plasmas with strict h/w limits of 1.1 Wb in the first trial by combining a unique magnetic configuration and 2nd harmonic ECH preionization, Circular ohmic plasma discharge (ECH assisted) Hydrogen plasma First plasma (107 kA, shot No. 794) was achieved on June 13, 2008. The target of first plasma was achieved. Plasma discharge ECH assisted ohmic plasma dischargeBasic plasma parameters for first plasmna

13. 13 ECH pre-ionization study (ITPA HPRT) Pre-ionization study in terms of beam launch direction ECH pre-ionization test according to beam launch directions Toroidal scan : normal, co- and counter-oblique injection (+10 0 ~ -10 0 ) Vertical scan : (z= +10 ~ -10 cm) The pre-ionization of oblique beam launch was more efficient than the perpendicular launch. ECH antenna - mirror pivot R=2800 y=-252 x=-279 Bt Ip Nm-port Co-injection CNT-injection ECH launch directionsPre-ionization according to beam launch direction

14. 14 ECH pre-ionization study ECH power threshhold for 2 nd harmonic plasma breakdown was about 280 kW. At least 320 to 350 kW of ECH power was needed for reliable breakdown in KSTAR 1 st plasma campaign. The plasma breakdown time has been reduced with higher ECH power. 280 kW(#1078, black) 320 kW(#1079, red) 350 kW(#1080, blue) ECH pre-ionization according to ECH powerPre-ionization delay time No breakdown (P ECH : 280 kW) Pre-ionization study in terms of beam power

15. 15  Shot 1127 @ t=543.1 msec  I pl,mea = 97.1 kA, I pl,rec =98.3 kA, I vv = 59.3 kA  z out = -9.1 (cm), R out = 161.2 (cm), a = 35.2 (cm)  z c = -9.3 (cm), R c = 164.9 (cm)  Good condition no. (7.84 e3) Using all MP’s and FL’s with optimized fitting weight Vacuum vessel and real limiter structure are considered Good agreement with CCD camera EFiT Reconstruction Plasma Current Zout Rout

16. 16 - The effect of Incoloy is not included By O. Hopkins EFiT Reconstruction Shot 1127

17. 17 Issues for KSTAR magnetics KSTAR has an inherent source of magnetization inside the PF & TF coils Incoloy 908 is the jacket material for superconducting strand Weakly ferromagnetic with max μ r ~10 (saturation B~1T) Toroidally symmetric but problematic for field-null quality Experimental findings : Downward shift of plasma Lower measured loop voltage than the calculated by the circuit equations PF coil currents decay faster than the calculated by the circuit equations => Need additional up-down asymmetric sources of current and field Cryostat is a potential source of up-down asymmetry Large current at the lower cryostat will drive plasma downward Other discrepancy might be due to cryostat current also Incoloy 908 Understanding Magnetics

18. 18 A genuine reconstruction code has been developed to cope with nonlinear magnetization from Incoloy 908 in CICC and partially validated with the measurements still require better understanding of the magnetic probe measurements and its validation still large discrepancy between the measured and the calculated vessel current developed analysis tools are directly applicable to ITER TBM analysis The cryostat is a potential source of up-down asymmetry according to the calculations, rather large current flows in the cryostat(~200kA) better agreement with loop voltage measurements with the cryostat circuit potentially problematic in ITER also By upgrading and thorough validation of the magnetic diagnostics in next campaign, these issues will be examined in more quantitative way Understanding Magnetics

19. 19 DC glow discharge cleaning Glow discharge at zero field condition at night (H 2 & He) RF discharge cleaning between shots DC glow is not acceptable due to continuously applied TF field. KSTAR ICRH system (2 MW, 300 sec, 25 -60 MHz) used for discharge cleaning between shots at 30 kW (30 MHz). 2 seconds pulse in every 12 seconds for 5-10 minutes just after plasma shot. Wall conditioning (ITPA HPRT) DC glow discharge using the probe RF discharge using the ICRF system Two kinds of discharge cleaning methods

20. 20 Line density variation due to ICRH He cleaning ICRH(He)5min Between shots Line density decreases shot by shot ICRF-DC was successfully started without major fault due to the appropriate protection system. Line density was affected by the shot to shot discharge cleaning. Exact assessment of residual gas variation due to DC was difficult due to background signals from the pumping lines in RGA system. Quantitative measurement of wall condition is required with better-set RGA system and increasing pulse length of RF power. RF discharge cleaning effects 856857858 RGA signal during DC and plasma shots Wall conditioning

21. 21 Dust collection and analysis Dust generation was often observed by visible CCD cameras. Cause : change of heating directions, plasma movement, etc. Events from in-board limiter and MD protections Collected dusts at 10 different in-vessel positions using sticky carbon tape. Large dispersion: 100nm-20um. Two major peaks at ~100 nm and 2um. Detected components: C, Si, Mn, P, S, Ni, Cr, Fe, Cl, Ag, Al, Mg  Inboard limiter, Diagnostics (mirror, etc) Dust collection and analysis was possible from the virgin operation.

22. 22 Most of the targeted values of the 1 st campaign were achieved. Results of the 2008 campaign ClassificationsTargetAchievedRemarksFinal Spec. ∙VV base pressure ∙Cryostat base pressure ∙Total leak rate ≤ 5.0x10 -7 mbar ≤ 1.0x10 -4 mbar ≤ 1.0x10 -4 mbar·l/s 3.0x10 -8 mbar 1.7x10 -7 mbar·l/s OK  ∙SC coil temperature ∙Thermal shield temperature (In/out) ∙Temperature distribution ≤ TF & PF : 5 K ≤ 55 / 70 K ≤ 50 K TF & PF : 4.48 K 51 / 72 K 48 K OK  ∙SC transition temp. ∙Joint resistance ∙Coil insulation ∙TF current ∙TF field at major radius ∙PF coil current ∙PF Blip period Nb 3 Sn : 18.3 K NbTi : 9.2 K ≤ 5 nΩ > 100 MΩ ≥ 15 kA ≥ 1.5 T 4 kA ≥100 ms Nb 3 Sn : 18±0.2 K NbTi : 9.9±0.1 K 0.5 ~ 2 nΩ > 3,000 MΩ 15 kA 1.5 T 4 kA 50 ～ 150 ms OK  35 kA 3.5 T 25 kA  ∙ECH for pre-ionization ∙Plasma current ∙Plasma duration ∙Plasma duration ≥100 kA ≥ 400 kW (0.2 s) ≥ 100 kA ≥ 0.1 s 480 kW (0.4 s) 133 kA 0.86 s 0.33 s OK  2,000 kA 300 s

23. 23 Vacuum pumping system operation Cryo-facility operation Superconducting State Plasma Exp. Pumping down / Leak check / Wall conditioning Cool-down from 300 K to 4.5 K and warmup Maintain 4.5 K

24. 24 Available operation time in 2009-2010 2009 Operation 2009123456789101112 2010 Operation 2010123456789101112 IAEA FEC In Korea Vacuum & wall conditioning Cool-down & warmup SC magnet operation Plasma exp. Vacuum & wall conditioning Cool-down & warmup Plasma exp. H/W upgrade SC magnet operation

25. 25 System availability for 2009-2010 operation 200820092010 SC Magnetic system TF coils PF coils & leads 15 kA 4 kA unipolar Up/Low series 35 kA 4 kA bipolar Up/Low series 35 kA 20 kA bipolar Up/Low separate (4 more PF PS) In-vessel system In-vessel coil PFC Wall conditioning Inboard limiter Glow DC, RF DC Inboard limiters + boronization Vertical control Divertor / limiters Passive stabilizer + PFC baking Heating system ECH ICRH NBI LHCD 0.5 MW (84 GHz) 0.03 MW (30 MHz) 0.5 MW (84 GHz) 0.3 MW (45 MHz) 0.5 MW (84 GHz) 0.5 MW (110 GHz) 1 MW 0.5 MW Infra system Grid Power50 MVA (154 kV) 100 MVA (154 kV)

26. 26 Operational parameters in 2009-2010 200820092010 Experimental parameters Peak TF field Operation TF field Flux Ip Plasma shape Gas 1.5 T ~ 1 Wb < 133 kA Circular H 2 (He for DC) 3.5 T 1.5 T, 3.0 T ~ 2 Wb ~ 300 kA Circular H 2 (He for DC), D 2 3.5 T 1.5 T, 2.0 T, 3.0 T ~ 4 Wb < 1 MA Double null H 2, D 2 Control Plasma controlPF blip & start up Ip, Rp, ne PF zero-crossing Ip, Rp, ne IVC control Ip, Rp, Zp, shape Diagnostics Diagnostic systemsMD/ MMWI/ ECE / Hα/ filterscope/ ViS. TV MD/ MMWI / ECE / Hα/ filterscope/ Vis. TV PD / XCS / Soft X-ray / Reflect./ XCS (1 set) / Bolometer (resistive) / MD / MMWI / ECE/ Hα/ filterscope/ Vis. TV PD / XCS / Soft X-ray / Reflect. TS/ Hard X-ray / Fast neutral / ECEI / IRTV/Fast Ion Loss Detector

27. 27 FY 2008FY 2009FY 2010FY 2011FY 2012 Operation (Vac,CD & WU) ‘08. 3 ~ ‘08. 8 (6 mon.) ‘09. 8 ~ ‘09.12 (5 mon.) ‘10.6 ~ ‘10. 11 (6 mon.) ‘11. 4~ ‘11. 9 (6 mon.) ‘12. 2 ~ ‘12. 7 (6 mon.) Experimental Goals First plasma startup 2 nd Harmonic ECH pre- ionization 1 st Harmonic ECH Pre- ionization Startup stabilization Shaping control & vertical stabilization Heating Confinement (L-H) Stabilization Heating Plasma–Wall Interaction Profile control RWM, ELM control Off-axis current drive Target Operation Parameters B T ~ 1.5 T I P > 0.1 MA t P > 0.1 s Te > 0.3 keV Ti ~ 0 keV Flux ~ 1 Wb Shape ~ Circular Gas : H 2 B T ~ 3 T I P > 0.3 MA t P > 2 s Te > 0.3 keV Ti ~ 0.3 keV Flux ~ 2 Wb Shape ~ Circular Gas : H 2,, D 2 B T ~ 3 T I P < 1 MA t P ~ 10 s Te ~ 1 keV Ti ~ 1 keV Flux ~ 4 Wb Shape ~ DN(double null) Gas : H 2, D 2 B T ~ 3 T I P < 1.5 MA t P ~ 10 s Te ~ 1 keV Ti ~ 3 keV Flux ~ 6 Wb Shape ~ DN & SN Gas : D 2 B T ~ 3 T I P < 2 MA t P > 100 s (0.5 MA) Te ~ 1 keV Ti ~ 5 keV Flux ~ 8 Wb Shape ~ DN & SN Gas : D 2 PFC & Wall conditioning Inboard limiter (belt) Gas puff Inboard limiter (w/o cooling) Boronization Divertor / Passive plate PFC baking In-vessel coil Cryopump operation PFC cooling Pellet Magnetic control TF : 1.5 T PF : 4 kA unipolar TF : up to 3.5 T PF : +/-4 kA TF : up to 3.5 T PF : +/-10 kA IVCC : VS, RS TF : up to 3.5 T PF : +/-15 kA IVCC : FEC. RMP TF : up to 3.5 T PF : +/-20 kA IVCC : RMP, RWM Heating operation ECH(84G): 0.5MW, 0.4sECH(84GHz): 0.5MW, 2s ICRH(45MHz): 0.3MW, 10 s ECH(84/110GHz): 0.5MW ICRH(45MHz): 1MW, 10 s NBI: 1.0MW, 10s LHCD: 0.5MW, 2s ECH(84/110GHz): 0.5MW ICRH(45MHz): 2MW, 10 s NBI: 2.5MW, 10s LHCD: 0.5MW, 2s ECCD(170GHz): 1MW, 10s ECH(84/110GHz): 0.5MW ICRH(45MHz): 2MW, 300 s NBI :5MW, 300s LHCD : 1MW, 2s ECCD(170GHz): 1MW, 300s Diagnostics MD (77 Ch)/ MMWI / ECE / H  / filterscope / VS / TV MD/ MMWI / ECE / H  / filterscope / VS / TV PD / XCS (1 set) / Bolometer (resistive) / Reflect. / Soft X-ray MD / MMWI / ECE / H  / filterscope / VS / TV PD / XCS / Bolometer / Reflect. / Soft X-ray Thomson Scattering / Hard X-ray / Fast neutral / IR TV / ECEI MD / MMWI / ECE / H  / filterscope / VS / TV PD / XCS / Bolometer / Reflect. / Soft X-ray TS / Hard X-ray / Fast neutral / IR TV / ECEI MSE / FIR / CES / neutron MD / MMWI / ECE / H  / filterscope / VS / TV PD / XCS / Bolometer / Reflect. / Soft X-ray TS / Hard X-ray / Fast neutral / IR TV / ECEI MSE / FIR / CES / neutron / VUV MIR / BES / CI / Near-term experiment plan

28. 28 Research topics in 2009-2010 Power supply control TF magnet test up to 35 kA ; B TF up to 3.5 Tesla @ R=1.8m PF magnet & power supply control for zero-crossing : Flux up to 2 Weber Vertical & radial stability control using IVCC (‘10) Plasma control Plasma current and position control (Ip, Rp) Plasma shape control (Rp, Zp, kappa, delta) (‘10) Magnetic probes & analysis Refined characterization of the magnetics with additional sensors and electron beam system. (quantifying field errors, calibration of magnetic probes) Understanding the material (Incoloy908) and geometry effects on plasma Magnetics

29. 29 Research topics in 2009-2010 ECH pre-ionization Full exploitation of 84 GHz & 110 GHz Gryotron Further Investigation of ECH assisted pre-ionization Dependence on 1 st & 2 nd harmonics, injection directions ICRH heating and RF discharge cleaning Exploitation of ICRH heating Exploit RF discharge cleaning between shots Commissioning of additional heating hevices NBI (1 MW), LHCD (0.5 MW) (‘10) Heating researches

30. 30 Research topics in 2009-2010 Wall conditioning & wall interaction Quantitative approach on wall conditioning & wall recycling Hydrogen recycling/retention under different wall condition(Boronization, RFGDC, ICRH DC) Characterization of the dust behavior Experiments Disruption studies Possible MHD Studies ; sawtooth manipulation, locked mode Experiments based on the collected proposals (domestic /international) Data access and collaboration Data access, analysis, logging Remote experiments participation & operation Other researches

31. 31 Experimental Proposals 37 experimental proposals registered through internet In 7 categories System commissioning (5) Magnetic configuration and equilibrium reconstruction (7) Startup and current ramp-up (4) Diagnostics (4) Heating and current drive (3) Wall conditioning (3) Instabilities (7) Transport and confinement (4) 28 domestic / 9 international NFRI (18) Postech (7) KAERI (3) GA (5) PPPL (2) ORNL (1) Far-Tech (1)

32. 32 Remote Experiment (2009, Collaboration with GA) discussion KSTAR site RSL H323 Non-PCS parameter confirm PCS parameter input PCS Confirm “Next Shot is ready” DSLCMO Y N Run Shot parameter Input / limit check Result transfer Shot analysis Shot log Wait for live shot updates Shot summary put to web portal EPICS / H.323 MDSplus Remote site Authorization tools Deputy session leader (DSL) Remote session leader (RSL) Chief Machine Operator (CMO) Local operators Assistant Physics Operator Connection / transfer Support H323 video. PCS remote GUIWeb logbook & summary PCS wave serverRDB server Electronic authorization layer MDSplus

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34. 34 Operation target by 2012 H-mode operation control Plasma wall interaction research FEC and RWM control with ELM suppression using IVCC NTM suppression with ECCD Key milestones Physics targets 1 st KSTAR operation phase ends Achieve knowledge on supeconducting tokamak characteristics for H-mode operation

35. 35 Long-term plan (mainly by 2017) Physics target –Targetted for a milestone of ITER construction completion –Plays a role as an ITER pilot –Steady-state operation control –H-mode plasma stabilization for long pulse –AT mode (high beta) operation achievement with available heating systems

36. 36 Long-term experiment plan

37. 37 EU Support & Collaboration World Leading Experts (International) Fusion R&D Collaboration (International) KSTAR Collaboration Framework EU-WLEs US-WLEs JA-WLEs Profile Diag. Visualization (POSTECH) Reactor Engineering (SNU) Heating & CD (KAERI) Edge Diag. (Hanyang U.) Divertor & Simulation (KAIST) ITER Pilot R&D ITER-IO Simulation R&D SciDAC (US) IPERC (JA), etc. Co-Experiments ITER Members Non-ITER US Support & Collaboration JA Support & Collaboration

38. 38 Summary KSTAR first-plasma milestone achieved, even with limited hardware capabilities in wall-conditioning, diagnostics, power supply systems etc. 2008 operation campaign was accomplished in 5 months without any serious fault. International collaborations were essential to achieve the milestones. To get meaningful results in 2009 & 2010 campaign, Acceleration in hardware upgrade, Careful system operation and concentrated experiment plan, Accurate measurement and in-detail understanding on SC tokamak operation, and Stronger domestic and international collaboration are required. KSTAR control system played a key role to achieve first-plasma milestone.

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