TJ-II:Magnetic configuration

The magnetic configuration of TJ-II in vacuum is completely determined by the currents flowing through the external coils. Magnetic configurations are labelled as 'xxx_yy_zz', where

• 'xxx': 10 times the current (in kA) in the circular coil
• 'yy': 10 times the current (in kA) in the helical coil
• 'zz': 10 times the current (in kA) in the vertical field coils

The toroidal field is not specified, as its value is adjusted to guarantee central absorption of the Electron Cyclotron Resonant Heating source.

Often used configurations are:

• 100_44_64 (a = 0.1925 m, ${\iota }_0/2\pi =1.55$, V_plasma = 1.098 m³)
• 100_48_65 (a = 0.191 m, ${\iota }_0/2\pi =1.591$, V_plasma= 1.09 m³)

Flexibility

Flexibility diagram of TJ-II magnetic configurations. Several lines of constant rotational transform are highlighted and labelled with the corresponding central $\iota /2\pi$-value.

TJ-II has considerable configurational flexibility, as observed in the 'flexibility diagram'.