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