This thesis is about the retarding field ion energy analyzer (RFA), which was fabricated and was tested on KAIST tokamak plasma. It also introduces KAIST tokamak plasma and its operation. When the main discharge is operated, in the edge region RFA's raw data was achieved and analyzed. The proper grids size and inter-length between grids was considered.
There are a little problems in KAIST tokamak plasma operation to produce steady state plasma and RFA must be improved for more convinced plasma diagnostics. It is also requested to set up other diagnostics for confirming RFA and connecting between analysis.
