A fast reciprocating Langmuir (electrostatic) probe system (RPS) was installed at High-Field-Side baffle (Photo from VV) in Jan.-Mar. 2001.
HFS scrape-off layer (SOL) plasma data, i.e. profiles of electron temperature, ion saturation current and floating potential, were for the first time, measured in divertor tokamak.
|Langmuir probes:||Two double probes for Te, Is measurement at up-stream and down-stream sides of the field lines (i.e. Mach probe), and a floating probe for potential measurement.
Head and 5 electrodes are made of carbon fiber composite (CFC).
|Spatial resolution:||1-2 mm in radial direction.
It has provided high spatially resolved profiles of the local electron temperature (Te) and ion saturation current (Is) in the SOL.
|Scanning speed:||35cm for ~0.5s (~70 cm/s)|
|Driving component:||a compact pneumatic cylinder and steel springs.
Total mass of the moving components is about 30kg.
|Position:||P-2 section, U1 vertical port.|
|Operation :||stopped from 2002 to 2004, due to no budget to repair broken probe head.
Probe head and electrodes were repaired, and measurement starts from 2005.
 N. Asakura et al., Plasma Phys. Control. Fusion 44 (2002) 2101.
 N. Asakura et al., Plasma Phys. Control. Fusion 44 (2002) A313.
 N. Asakura et al., J. Nucl. Mater. 313-316, (2003) 820.
 N. Asakura et al., Nucl. Fusion, 44 (2004) 503.