||Pumps which remove gas, usually air, from a chamber, leaving it under vacuum. A variety of types are used, depending on the quality and degree of the vacuum needed.
||VV, establishes a confinement barrier in a tokamak and limits the heat flux to the toroidal field coils, and provides low-impurity volume for the reacting plasma.
|vertical displacement event
||VDE, a sudden shift in the vertical position of a tokamak plasma, frequently associated with a plasma disruption.
|vertical position control
||See vertical stability control
|vertical stability control
||A plasma whose vertical cross section is elongated vertically is unstable vertically if it is displaced from its nominal equilibrium position. A vertical field is applied to the plasma region to control this. If the plasma moves vertically it is necessary to tune this vertical field to force the plasma position back to the equilibrium. This is achieved using a feedback control system on the currents in the poloidal field coils, linked to plasma position sensors.
|very high mode
||VH-mode, a very high mode of energy confinement, first discovered in the DIII-D tokamak.
||vacuum transmission lines