Evaluation of Ion Temperature Using Ion Sensitive Probe in the Boundary Plasma of the JFT-2M Tokamak

In order to extend the capability of the ion sensitive probe (ISP) for the precise measurement of ion temperature, the dependence of the ion current on the height of the electron guard has been evaluated numerically by taking a finite width of the ion collector and the guard into account. It is shown that the ion temperature for strongly magnetized plasma could be experimentally deduced from the current–height characteristics for the ISP more accurately. The ISP technically improved by remote controllable heights has been applied to measure the ion temperature in the ohmically heated and L/H transition plasmas in JFT-2M tokamak.