TJ-II:Lithium Beam

TJ-II possesses a Lithium beam diagnostic. A thermal Li beam source, located at ∼ 80 cm from the observation region, has been used for the reconstruction of the SOL and edge parameters of the plasmas. A 16 channel photomultiplier array allowed the continuous recording of the radial profile of Li* emission. Detection of the Li* emission up to 8 cm inside the last closed flux surface (corresponding to r/a < 0.7) was possible. ^[1] ^[2] ^[3]

Lithium beam diagnostic setup. For a photo, see Helium Beam.

This diagnostic can no longer be used due to the use of Lithium for plasma wall conditioning, creating an overwhelming amount of Li background emission.

The system is located in sector C7. The signals are stored in the TJ-II database with the names 'LITIO1',...,'LITIO16'.

References

[1] B. Brañas et al., Atomic beam diagnostics for characterization of edge plasma in TJ-II stellarator, Rev. Sci. Instrum. 72, 602 (2001)

[2] F.L. Tabarés et al, Edge characteristics and global confinement of electron cyclotron resonance heated plasmas in the TJ-II Stellarator, Plasma Phys. Control. Fusion 43 (2001) 1023-1037

[3] F.L. Tabarés et al, Density control and plasma edge characterisation of ECRH heated plasmas in the TJ-II stellarator, Journal of Nuclear Materials 290-293 (2001) 748-752

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