THE POWER-SUPPLY SYSTEM FOR LANGMUIR PROBES ON RFX

A power supply system for Langmuir probes to be used on the reversed f ield pinch (RFP) thermonuclear fusion experiment RFX has been develope d. It is based on a full-bridge converter concept, using a pulse width modulation (PWM) technique, and is characterized by a 5 A, +/- 150 V rating. The power supply has been designed to ensure compatibility wit h the electromagnetic noise close to the machine and with the plasma, which behaves as a nonlinear rapidly varying load. The system has been optimized by numerical simulations. Tests in the laboratory and on th e experiment have been performed in a wide range of working conditions , and the system has been proven to suit fairly well the RFX experimen tal conditions.