h-1 heliac: parameters 3 period heliac: 1992 major radius1m minor radius0.1-0.2m vacuum chamber33m 2...
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H-1 Heliac: Parameters3 period heliac: 1992Major radius 1mMinor radius 0.1-0.2mVacuum chamber 33m2
Aspect ratio 5+Magnetic Field 1 Tesla (0.2 DC)Heating Power 0.2(0.4)MW GHz ECH
0.3MW 6-25MHz ICH
Parameters: achieved / expected n 3e18/1e19
T ~100eV(Ti)/0.5-1keV(Te)
0.1/0.5%
H-1 Heliac: Parameters3 period heliac: 1992Major radius 1mMinor radius 0.1-0.2mVacuum chamber 33m2
Aspect ratio 5+Magnetic Field 1 Tesla (0.2 DC)Heating Power 0.2(0.4)MW GHz ECH
0.3MW 6-25MHz ICH
Parameters: achieved / expected n 3e18/1e19
T ~100eV(Ti)/0.5-1keV(Te)
0.1/0.5%
Complex geometry requires minimum 2D diagnostic
Cross-section of the magnet structure showing a 3x11 channel tomographic diagnostic
Plasma production and heating: resonant and non-resonant RF
0
0.5
1
1.5
2
2.5
3
3.5
0 1000 2000 3000 4000 5000 6000 7000 8000
(E_DENS IN*10 1̂8m -̂3)
Hydrogen
Series3
Series4
Series5
Poly.((E_DENS IN*10 1̂8m -̂3))Poly.(Series3)
Poly.(Series4)
Helicon wave (non resonant) heating Ion cyclotron resonant heating:Hydrogen, andMinority H in He
argon
H:He
H
CH On axis
<ne> 1018m-3
• Non-resonant heating is flexible in B0, works better at low fields.
• Resonant heating is much more successful at high fields.
= Chon axisMagnetic Field (T)
helicon/frame antenna
Update with helium, Tesla
2D electron density tomography
coherent drift mode in argon, 0.08TH density profile evolution (0.5T rf)
Helical axis non-circular need true 2D
Movie Clip (AVI)
Raw chordal data Tomographically inverted data
radi
us
Ion Temperature Camera
Hollow Ti at low B0
0 10 20 30 time (ms)
Inte
nsity
te
mpe
ratu
re
rot
atio
n
Confinement transitions in H-1
6
5
4
3
2
1
00
0 . 5
1r / a
01 0
2 03 0
t ( m s )
I s i ( )m A( a )
M o d u l a t i o ni n v e r s i o n
“Pressure” (Is) profile evolution during transition
transition
PRF (kW)
B0(T)
•many features in common with large machines
•associated with edge shear in Er
•easily reproduced and investigated
Parameter space map, ~ 1.4
ExB and ion bulk rotation velocity in high confinement mode: magnetic structure causes
viscous damping of rotation
-6E+6
-4E+6
-2E+6
0E+0
2E+6
15 20 25
V_pol(cm/s)
(x10)
VExB
r(cm) (cm)
LCFS (cm)
pttpir BVBVPzen
E 1
0 0
Vp, Vt << VExB ~ 1/(neB) dPi/dr
Radial force balance
Mass (ion) flow velocities much smaller than corresponding VExB
Bulk Rotation Impeded