Triangularity: Difference between revisions

From FusionWiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
[[File:Geometry.png|400px|thumb|right|Sketch of tokamak geometry, including separatrix]]  
[[File:Geometry.png|400px|thumb|right|Sketch of tokamak geometry, including separatrix]]  
The triangularity refers to the shape of the poloidal cross section of the Last Closed [[Flux surface]] (LCFS) or [[separatrix]] of a [[tokamak]].  
The triangularity refers to the shape of the poloidal cross section of the Last Closed [[Flux surface]] (LCFS) or [[separatrix]] of a [[tokamak]].  
Assuming:
Assuming<ref>T.C. Luce, [[doi:10.1088/0741-3335/55/9/095009|Plasma Phys. Control. Fusion '''55''' (2013) 095009 ]]</ref>:
* ''R<sub>0</sub>'' is the major radius of the midpoint of the 2 intersections of the LCFS or separatrix with the equatorial plane (''Z'' = 0).
* ''R<sub>max</sub>'' is the maximum value of ''R'' along the LCFS or separatrix.
* ''a'' is the minor radius of the plasma, defined as the radial difference between the 2 intersections of the LCFS or separatrix with the equatorial plane (''Z'' = 0), divided by 2.
* ''R<sub>min</sub>'' is the minimum value of ''R'' along the LCFS or separatrix.
* ''R<sub>geo</sub>'' is the geometric major radius, defined as ''(R<sub>max</sub> + R<sub>min</sub>)/2''.
* ''a'' is the minor radius of the plasma, defined ''(R<sub>max</sub> - R<sub>min</sub>)/2''.
* ''R<sub>upper</sub>'' is the major radius of the highest vertical point of the LCFS.
* ''R<sub>upper</sub>'' is the major radius of the highest vertical point of the LCFS.
* ''R<sub>lower</sub>'' is the major radius of the lowest vertical point of the LCFS.
* ''R<sub>lower</sub>'' is the major radius of the lowest vertical point of the LCFS.
Line 16: Line 18:
* [[Toroidal coordinates]]
* [[Toroidal coordinates]]
* [[Effective plasma radius]]
* [[Effective plasma radius]]
== References ==
<references />

Revision as of 15:11, 17 June 2014

Sketch of tokamak geometry, including separatrix

The triangularity refers to the shape of the poloidal cross section of the Last Closed Flux surface (LCFS) or separatrix of a tokamak. Assuming[1]:

  • Rmax is the maximum value of R along the LCFS or separatrix.
  • Rmin is the minimum value of R along the LCFS or separatrix.
  • Rgeo is the geometric major radius, defined as (Rmax + Rmin)/2.
  • a is the minor radius of the plasma, defined (Rmax - Rmin)/2.
  • Rupper is the major radius of the highest vertical point of the LCFS.
  • Rlower is the major radius of the lowest vertical point of the LCFS.

The upper triangularity is then defined as follows:

and similar for δlower. The overall triangularity is defined as the mean of δupper and δlower.

See also

References