First measurement of confinement properties in TPE-RX reversed field pinch

Electron and ion temperatures Te0 and Ti, respectively, are measured and global confinement properties are estimated at Ip £ 400 kA for the first time in the TPE-RX reversed field pinch (RFP) using a single point Thomson scattering system and a single chord neutral particle energy analyser, respectively. The values of Te0 and Ti range from 0.2 to 1 keV and from 0.2 to 0.4 keV, respectively, at Ip ~ 350 kA. The I/N value (N is the line density) is relatively high ( = 12×10-14 A m) in comparison with those of other RFP machines. The poloidal beta bp and energy confinement time tE are comparable to those in similarly sized RFP plasmas such as the MST and RFX plasmas, namely, bp = 5-10% and tE = 0.5-1.0 ms. The behaviour of the global confinement properties and the implication of this result are discussed.