TJ-II:Langmuir Probes

TJ-II has two fast reciprocating drives for Langmuir probes (with a displacement velocity of approximately 1 m/s). ^[1] ^[2] ^[3] Probe drive 1 is located at φ = 38.2°, R=134 cm (sector D4) and probe drive 2 at φ = 195° (sector B2).

Location of the reciprocating Langmuir probes at TJ-II

Probe heads

Several different heads can be mounted on the reciprocating drives: e.g., staircase Langmuir probes, a rake probe (as of 2009), or a multi-pin Langmuir probe (2010). A biasing probe has also been used.

Photo of a staircase Langmuir probe head with three sets of measurement pins	Photo of a multipin Langmuir probe head
Photo of a 12-pin Langmuir rake probe head	Photo of an 8-pin Langmuir rake probe head

References

↑ M.A. Pedrosa et al, Fast movable remotely controlled Langmuir probe system, Rev. Sci. Instrum. 70 (1999) 415
↑ E. Calderón et al, On the Influence of Probe Presheath on the Measurement of Fluctuation and E × B Turbulent Transport by Langmuir Probes, Contributions to Plasma Physics 44, Issue 7-8 (2004) 700 - 704
↑ M.A. Pedrosa et al, Evidence of Long-Distance Correlation of Fluctuations during Edge Transitions to Improved-Confinement Regimes in the TJ-II Stellarator, Phys. Rev. Lett. 100 (2008) 215003

[1] M.A. Pedrosa et al, Fast movable remotely controlled Langmuir probe system, Rev. Sci. Instrum. 70 (1999) 415

[2] E. Calderón et al, On the Influence of Probe Presheath on the Measurement of Fluctuation and E × B Turbulent Transport by Langmuir Probes, Contributions to Plasma Physics 44, Issue 7-8 (2004) 700 - 704

[3] M.A. Pedrosa et al, Evidence of Long-Distance Correlation of Fluctuations during Edge Transitions to Improved-Confinement Regimes in the TJ-II Stellarator, Phys. Rev. Lett. 100 (2008) 215003

[1]

[2]

[3]

TJ-II:Langmuir Probes

Probe heads

See also

References