Robust Langmuir probe circuitry for fusion research

Langmuir probes attached to the plasma facing components of fusion experime nts are biased with constant or swept voltages to obtain measurements of pl asma parameters such as electron temperature and density. The circuitry use d must be rugged and protect the power supplies and electronics against gen erally harsh conditions and sudden discharge terminations, or disruptions. Modularity, ease of repair and expandability are important because short-li ved radiation from neutron activation is often present after the discharges , preventing access to the circuitry. We report the implementation of modul ar probe circuitry featuring robust protection, remote testing and reset an d easy maintenance and expandability, achieved by using DIN-rail modules. ( C) 2001 American Institute of Physics.