Fast reciprocating Langmuir probe assembly for KSTAR

Summary form only given, as follows. Fast reciprocating Langmuir probe assembly (FRLPA) is designed to measure spatial profiles of plasma parameters in the divertor/SOL (scrape-off layer) region of the Korea Superconducting Tokamak Advanced Research (KSTAR) machine. The main components of the FRLPA are the probe drive system, the control and data acquisition system, and probe head system. The probe drive system has the two-step movement such as slow motion for adjusting stand-by position and then fast one for probe reciprocating for edge plasma. Recently, the preliminary data acquisition system is set up for its performance test Finally, the design of the probe head is being modified continuously by using results from the thermal analysis on probe geometry under high heat flux environment that will be estimated in the KSTAR machine. In this work, the detailed specifications of the KSTAR FRLPA will be described, and its current engineering design activities will be presented. In addition, technical issues from the fabrication and its performance test will be discussed.