The technology of the plasma experiment in HELIOS

The technology of the plasma experiment on board the solar probe HELIOS is described. Emphasis is on the sensors and multipliers, their qualification in different steps, i.e., component level, experiment level and system level. A short description of the entire experiment and its scientific objectives is followed by a detailed discussion of the requirements to be met on the experiment. The fulfillment of these requirements is examined. Channel electronmultipliers, vacuum techniques and microelectronic devices in ceramic techniques are subjects of special consideration.