Triangularity
From FusionWiki
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]}:
- R_{max} is the maximum value of R along the LCFS or separatrix.
- R_{min} is the minimum value of R along the LCFS or separatrix.
- R_{geo} is the geometric major radius, defined as (R_{max} + R_{min})/2.
- a is the minor radius of the plasma, defined as (R_{max} - R_{min})/2.
- R_{upper} is the major radius of the highest vertical point of the LCFS or separatrix.
- R_{lower} is the major radius of the lowest vertical point of the LCFS or separatrix.
The upper triangularity is then defined as follows:
- $ \delta_{upper} = (R_{geo}-R_{upper})/a $
and similar for δ_{lower}. The overall triangularity is defined as the mean of δ_{upper} and δ_{lower}.
See also
References
- ↑ T.C. Luce, Plasma Phys. Control. Fusion 55 (2013) 095009