Introduction to Nuclear Fusion Prof. Dr. Yong-Su Na To build a sun on earth - Open magnetic confinement - Closed magnetic confinement 2 What is closed magnetic confinement? 3 Open Magnetic System B sin 2 min Bmax v|| loss cone loss cone - Suffering from end losses J.P. Freidberg, “Ideal Magneto-Hydro-Dynamics”, lecture note A. A. Harms et al, “Principles of Fusion Energy”, World Scientific (2000) 4 Open Magnetic System Magnetic field Is this motion realistic? ion Dunkin donuts (2010) 5 Closed Magnetic System Magnetic field Donut-shaped vacuum vessel ion 6 Closed Magnetic System 7 Closed Magnetic System Magnetic field R 0 a Plasma needs to be confined ion R0 = 1.8 m, a = 0.5 m in KSTAR 8 Closed Magnetic System Magnetic field R 0 a Plasma needs to be confined ion R0 = 6.2 m, a = 2.0 m in ITER 9 Closed Magnetic System Toroidal Field (TF) coil Magnetic field Toroidal direction Applying toroidal magnetic field ion 3.5 T in KSTAR, 5.3 T in ITER 10 Closed Magnetic System Toroidal Field (TF) coil Toroidal direction Applying toroidal magnetic field 3.5 T in KSTAR, 5.3 T in ITER 11 Closed Magnetic System Toroidal Field (TF) coil Magnetic field Toroidal direction Magnetic field of earth? 0.5 Gauss = 0.00005 T ion 12 http://www.crystalinks.com/earthsmagneticfield.html Closed Magnetic System Magnetic field Magnetic field of earth? 0.5 Gauss = 0.00005 T ion http://www.transformacionconciencia.com/archives/2384 13 Closed Magnetic System Magnetic field ion 14 Lesch, Astrophysics, IPP Summer School (2008) Closed Magnetic System Magnetic field ion electron What kind of drift motions? ion 15 Closed Magnetic System Where does the gradient come from? B 1 B(R) R 16 R http://magnetoglide.wordpress.com/ Closed Magnetic System Where does the gradient come from? B B J 0 B dl NI 0 c 1 NI B(R) B (R) 0 c R 2R 17 http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/toroid.html Closed Magnetic System mv2 R B v || 0 0 ion D,R qB2 R2 +++ 0 1 BB v v r D,B 2 L B2 B mv2 BB 2qB B2 - - - electron m 1 v2 v 2 e D v|| Z 1 q R B (R ) 2 B(R) 0 0 R 18 Closed Magnetic System ion +++ Electric field, E - - - electron 19 Closed Magnetic System ion +++ ExB drift EB E R Electric v D,E 2 field, E B B (R0 ) R0 - - - ExB drift electron A. A. Harms et al, “Principles of Fusion Energy”, World Scientific (2000) 20 Closed Magnetic System ion +++ ExB drift Electric field, E - - - ExB drift electron Poloidal magnetic field required TokamakThen, .VS. how Stellarator to? 21 What is a tokamak? 22 Closed Magnetic System Will be the plasma current driven if a toroidal magnetic field is applied? ion +++ ExB drift Electric field, E - - - ExB drift electron Poloidal magnetic field required HowPlasmaTokamak to Then,drive current .VS. plasmahow Stellarator→ to? Tokamak current? 23 Tokamak Faraday‘s law d v B dS dt S 24 http://www.electronics-tutorials.ws/electromagnetism/electromagnetic-induction.html Tokamak Faraday‘s law d v B dS dt S 25 Tokamak Central Solenoid (CS) Plasma Transformer 26 http://www.electronics-tutorials.ws/electromagnetism/electromagnetic-induction.html Tokamak Central Solenoid (CS) Plasma Poloidal field Pulsed Operation! 27 http://www.electronics-tutorials.ws/electromagnetism/electromagnetic-induction.html Pulsed Operation Faraday‘s law Plasma Current d (MA) v B dS dt S t (s) CS Coil Current Coil Limit (stress, heating) (kA) t (s) Inherent drawback of Tokamak! 30 Steady-State Operation Plasma Current (MA) t (s) CS Coil Current (kA) t (s) d/dt ~ 0 Steady-state operation by self-generated and externally driven current 30 Tokamak Adding vertical (equilibrium) field coils (PF: Poloidal Field) 30 Tokamak Adding vertical (equilibrium) field coils (PF: Poloidal Field) 31 Tokamak Plasma expansion force I p Bv Force balance by vertical field coils: Plasma positioning 32 J.P. Freidberg, “Ideal Magneto-Hydro-Dynamics”, lecture note Tokamak X PF coils ● X current current Force X Force X ● coil coil X Plasma shaping by PF coils 33 Tokamak The plasma shape can be modified by PF coil currents. 34 Tokamak 35 Tokamak Adding vertical (equilibrium) field coils (PF: Poloidal Field) B B J J Plasma positioning & shaping by PF coils 36 Tokamak Invented by Igor Tamm and Andrei Sakharov in 1952 Toroidalnaja kamera magnitnaja katushka (Toroidal chamber magnetic coil) 37 Tokamak Cutaway of the Toroidal Chamber in Artsimovitch's Paper Research on Controlled Nuclear Fusion in the USSR Toroidalnaja kamera magnitnaja katushka (Toroidal chamber magnetic coil) 38 1958 IAEA FEC, Geneva, Switzerland T1: The world’s first tokamak, Kurchatov Institute, Moscow Russia http://www.iter.org/newsline/55/1194 39 Tokamak R a JET (Joint European Torus): 0 = 3 m, = 0.9 m, 1983-today http://imgarcade.com/1/spherical-tokamak/ 40 Tokamak R a JET (Joint European Torus): 0 = 3 m, = 0.9 m, 1983-today 41 Tokamak R a JET (Joint European Torus): 0 = 3 m, = 0.9 m, 1983-today 42 Tokamak http://cafe.naver.com/gamebox26.cafe?iframe_url=/ArticleRead.nhn%3Farticleid=16140 43 Tokamak KSTAR (Korea Superconducting Tokamak Advanced Research): R a 0 = 1.8 m, = 0.5 m, 2007-today 44 Tokamak KSTAR (Korea Superconducting Tokamak Advanced Research): R a 0 = 1.8 m, = 0.5 m, 2007-today 1st campaign (2008) 2nd campaign (2009) 3rd campaign (2010) 45 Tokamak KSTAR (Korea Superconducting Tokamak Advanced Research): R a 0 = 1.8 m, = 0.5 m, 2007-today 46 Tokamak KSTAR (Korea Superconducting Tokamak Advanced Research): R a 0 = 1.8 m, = 0.5 m, 2007-today 47 Tokamak KSTAR (Korea Superconducting Tokamak Advanced Research): R a 0 = 1.8 m, = 0.5 m, 2007-today KSTAR 1st plasma Analyse the KSTAR 1st plasma 48 Tokamak B B J J 49 .