Transport implications of current drive by magnetic helicity injection

2001 ◽  
Vol 8 (11) ◽  
pp. 4839-4848 ◽  
Author(s):  
Ronald W. Moses ◽  
Richard A. Gerwin ◽  
Kurt F. Schoenberg
Keyword(s):  
Current Drive ◽  
Magnetic Helicity ◽  
Helicity Injection

RF current drive with magnetic helicity injection

1985 ◽  
Vol 33 (2) ◽  
pp. 257-264 ◽  
Author(s):  
D. K. Bhadra ◽  
C. Chu
Keyword(s):  
Steady State ◽  
Plasma Density ◽  
Electromagnetic Waves ◽  
Current Drive ◽  
Magnetic Helicity ◽  
Finite Frequency ◽  
Helicity Injection ◽  
Steady State Current ◽  
External Injection ◽  
Frequency Current

External injection of magnetic helicity into a plasma may be possible through the introduction of appropriately polarized electromagnetic waves. A concept of steady-state current-drive is presented, based on the validity of conservation of helicity (appropriately defined for finite frequency processes). It is shown that such external injection of helicity can maintain a steady-state current by compensating the volt-seconds consumed through plasma resistivity. Such a mechanism, if experimentally successful, is particularly interesting at high densities because the efficiency of the process does not depend on plasma density, as opposed to other radio-frequency current-drive techniques.

Simulations of Toroidal Current Drive without External Magnetic Helicity Injection

1997 ◽  
Vol 66 (2) ◽  
pp. 288-290
Author(s):  
Yoshiomi Kondoh ◽  
Masanori Yamaguchi ◽  
Katsuhisa Yokozuka
Keyword(s):  
Current Drive ◽  
Magnetic Helicity ◽  
Helicity Injection

scholarly journals Initiation and sustainment of tokamak plasmas with local helicity injection as the majority current drive

2018 ◽  
Vol 58 (9) ◽  
pp. 096002 ◽  
Author(s):  
J.M. Perry ◽  
G.M. Bodner ◽  
M.W. Bongard ◽  
M.G. Burke ◽  
R.J. Fonck ◽  
...  
Keyword(s):  
Current Drive ◽  
Tokamak Plasmas ◽  
Helicity Injection

scholarly journals Hemispheric injection of magnetic helicity by surface flux transport

2019 ◽  
Vol 631 ◽  
pp. A138 ◽  
Author(s):  
G. Hawkes ◽  
A. R. Yeates
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Solar Rotation ◽  
Surface Flux ◽  
Magnetic Helicity ◽  
Solar Cycles ◽  
Flux Transport ◽  
Transport Models ◽  
Radial Magnetic Field ◽  
Helicity Injection

Aims. We estimate the injection of relative magnetic helicity into the solar atmosphere by surface flux transport over 27 solar cycles (1700–2009). Methods. We determine the radial magnetic field evolution using two separate surface flux transport models: one driven by magnetogram inputs and another by statistical active region insertion guided by the sunspot number record. The injection of relative magnetic helicity is then computed from this radial magnetic field together with the known electric field in the flux transport models. Results. Neglecting flux emergence, solar rotation is the dominant contributor to the helicity injection. At high latitudes, the injection is always negative/positive in the northern/southern hemisphere, while at low latitudes the injection tends to have the opposite sign when integrated over the full solar cycle. The overall helicity injection in a given solar cycle depends on the balance between these two contributions. This net injected helicity correlates well with the end-of-cycle axial dipole moment.

Low Aspect Ratio Tokamak Formation and Sustainment by Coaxial Helicity Injection Current Drive

1995 ◽  
Vol 27 (3T) ◽  
pp. 333-336
Author(s):  
B. A. Nelson ◽  
T. R. Jarboe ◽  
D. J. Orvis ◽  
A. K. Martin ◽  
J. Xie ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Current Drive ◽  
Injection Current ◽  
Helicity Injection ◽  
Low Aspect Ratio ◽  
Coaxial Helicity Injection
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