Internal Transport Barrier: Difference between revisions
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No generally accepted definition for Internal Transport Barriers (ITBs) exists. Vaguely speaking, a radially localized reduction of transport | No generally accepted definition for Internal Transport Barriers (ITBs) exists. Vaguely speaking, the term refers to a radially localized reduction of transport for ions or electrons. | ||
== Physical mechanism == | == Physical mechanism == | ||
The mechanism for the formation of Internal Transport Barriers in magnetically confined plasmas is complex and not fully understood. Probably, it is related to the mechanism for the formation of the [[H-mode]] barrier, involving turbulence suppression by sheared flows, possibly associated with rational magnetic surfaces. | The mechanism for the formation of Internal Transport Barriers in magnetically confined plasmas is complex and not fully understood. Probably, it is related to the mechanism for the formation of the [[H-mode]] barrier, involving turbulence suppression by sheared flows, and possibly associated with rational magnetic surfaces. | ||
Factors contributing to the | Factors contributing to the formation of ITBs include: | ||
<ref>[http://dx.doi.org/10.1088/0029-5515/44/4/R01 J.W. Connor et al, ''A review of internal transport barrier physics for steady-state operation of tokamaks'', Nucl. Fusion '''44''' (2004) R1-R49]</ref> | <ref>[http://dx.doi.org/10.1088/0029-5515/44/4/R01 J.W. Connor et al, ''A review of internal transport barrier physics for steady-state operation of tokamaks'', Nucl. Fusion '''44''' (2004) R1-R49]</ref> | ||
* Power deposited inside the magnetic surface, and/or pressure gradients | * Power deposited inside the magnetic surface, and/or pressure gradients | ||
* [[Magnetic shear]] and the shape of the profile of the rotational transform | * [[Magnetic shear]] and the shape of the profile of the rotational transform | ||
* MHD activity | * MHD activity | ||
* Momentum torques | * Momentum torques (poloidal or toroidal) | ||
== References == | == References == | ||
<references /> | <references /> | ||
Revision as of 13:48, 27 August 2009
No generally accepted definition for Internal Transport Barriers (ITBs) exists. Vaguely speaking, the term refers to a radially localized reduction of transport for ions or electrons.
Physical mechanism
The mechanism for the formation of Internal Transport Barriers in magnetically confined plasmas is complex and not fully understood. Probably, it is related to the mechanism for the formation of the H-mode barrier, involving turbulence suppression by sheared flows, and possibly associated with rational magnetic surfaces.
Factors contributing to the formation of ITBs include: [1]
- Power deposited inside the magnetic surface, and/or pressure gradients
- Magnetic shear and the shape of the profile of the rotational transform
- MHD activity
- Momentum torques (poloidal or toroidal)