Fusion Engineering and Design 84 (2009) 867–874 Contents lists available at ScienceDirect Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes Plasma control system for “Day-One” operation of KSTAR tokamak Sang-hee Hahn a,∗ , M.L. Walker b , Kukhee Kim a , H.S. Ahn c , B.G. Penaflor b , D.A. Piglowski b , R.D. Johnson b , Jaehoon Choi a , Dong-keun Lee a , Jayhyun Kim a , S.W. Yoon a , Seong-Heon Seo a , H.T. Kim a , K.P. Kim a , T.G. Lee a , M.K. Park a , J.G. Bak a , S.G. Lee a , Y.U. Nam a , N.W. Eidietis b , J.A. Leuer b , A.W. Hyatt b , G.L. Jackson b , D. Mueller d , A.S. Welander b , G. Abla b , D.A. Humphreys b , W.C. Kim a , Yeong-Kook Oh a a National Fusion Research Institute (NFRI), Daejeon 305-333, Republic of Korea b General Atomics, P.O. Box 85608, San Diego, CA 92186-5608, USA c POSCON Corporation R&D Center, 101 Korea Techno Complex Building, Korea University, Seoul 136-713, Republic of Korea d Princeton Plasma Physics Laboratory, NJ, USA article info Article history: Available online 30 January 2009 Keywords: Tokamak Plasma control Poloidal field coil Real-time control Power supply control abstract A complete plasma control system (PCS) has been developed for KSTAR’s first plasma campaign as a collaborative project with the DIII-D team. The KSTAR real time plasma control system is based on a conceptual design by Jhang and Choi [Hogun Jhang, I.S. Choi, Fusion Engineering and Design 73 (2005) 35–49] and consists of a fast real-time computer/communication cluster and software derived from the GA-PCS [Penaflor, B.G., et.al., Fusion Engineering and Design, 83 (2) (2008) 176]. The system has been used for simulation testing, poloidal field (PF) coil power supply commissioning and first plasma control. The seven sets of up-down symmetric, superconducting PF coil/power supply systems have been successfully tested. Reflective memory (RFM) is utilized as the primary actuator/PCS real-time commu- nication layer and PCS synchronization with KSTAR timing system and slower control devices is achieved through an EPICS implementation. Consistent feedback loop times of 100 microseconds has been achieved during PF coil power supply testing and first plasma commissioning. Here we present the “Day-One” plasma control system in its final form for the first plasma experimental campaign of KSTAR and describe how the system has been utilized during magnet commissioning and plasma startup experiments. © 2008 Elsevier B.V. All rights reserved. 1. Introduction The KSTAR (Korea Superconducting Tokamak and Advanced Research) [1–3] project has completed its construction of the main tokamak device in its startup configuration and launched the first coil Commissioning at May 2008. As a part of the KSTAR dis- charge control system [4], the plasma control system (PCS) provides real-time controllability, creating and sustaining plasma during the experimental campaign. With software derived from the DIII-D PCS [5,6], a special adoption of original hardware for a few first real- time feedback control loops has been done with a newly designed communication layer for KSTAR. This work describes the configuration of the plasma control system developed for “Day-One” plasma operation, and summa- rizes the major performances achieved in both the superconducting magnet commissioning and the first plasma experiments. ∗ Corresponding author. Tel.: +82 42 870 1615; fax: +82 42 870 1619. E-mail address: hahn76@nfri.re.kr (S.-h. Hahn). 2. System hardware layout The PCS hardware consists of three parts for a complete feedback loop: data acquisition of plasma information from the tokamak, the real-time CPU for feedback calculations, and communication interfaces with the actuators. Fig. 1 shows the hardware layout for “Day-One” system. Adopting the original DIII-D PCS software but accepting the philosophy of the original conceptual design [7], the following new features specific to KSTAR has been implemented: (1) a spe- cial real-time data communication layer through for fast feedback, (2) employment of a full digital control interface for the set of 7 PF power supplies, and (3) integration between the KSTAR time- synchronization system and the EPICS (Experimental Physics and Industrial Control System) [8] software environments which now prevail through the entire KSTAR control system [9,10]. 2.1. Data acquisition Two kinds of plasma diagnostics were used for the first plasma control: 82 channels of magnetic diagnostics [11] and a single chan- 0920-3796/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2008.12.082