4,383
edits
Scaling law: Difference between revisions
→Power degradation
No edit summary |
|||
| Line 35: | Line 35: | ||
where α has a value of 0.6 ± 0.1. The reason for this behaviour has not been fully clarified. However, it seems obvious that an increase of ''P'' will lead to an increase of (temperature and density) gradients, and thus an increase of "free energy" available to instabilities and turbulence. This then leads to an increase of transport, producing the observed confinement degradation. | where α has a value of 0.6 ± 0.1. The reason for this behaviour has not been fully clarified. However, it seems obvious that an increase of ''P'' will lead to an increase of (temperature and density) gradients, and thus an increase of "free energy" available to instabilities and turbulence. This then leads to an increase of transport, producing the observed confinement degradation. | ||
This phenomenon is therefore due to plasma [[Self-Organised Criticality|self-organisation]]. | This phenomenon is therefore due to plasma [[Self-Organised Criticality|self-organisation]]. | ||
== Dimensionless parameters == | |||
Assuming quasi-neutrality, the relevant scaling laws can be cast into dimensionless forms that involve only three plasma parameters (apart from geometrical factors): | |||
<ref>B.B. Kadomtsev, Sov. J. Plasma Phys. '''1''' (1975)295</ref> | |||
:<math>\rho* = \frac{\rho_i}{a}</math> | |||
:<math>\beta = \frac{\left \langle p \right \rangle}{B^2/2\mu_0}</math> | |||
:<math>\nu*</math> | |||
== References == | == References == | ||
<references /> | <references /> | ||