A mass spectrometry probe, especially for magnetized plasmas

A high resolution mass spectrometry probe, to be placed in a uniform magnetic field, is presented. It comprises an ion acceleration zone, a polarized circular sector in order to generate in the zone an accelerating electric field, an ion collector and a conducting grid at the zone entrance in order to adjust the potential; the distance between the grid and the sector is designed to let ions to derive in the zone. The probe is especially aimed for identification of mono-charged or multi-charge ion species in a quiescent machine plasma and measurement of the species relative ionic densities; real time measurements are carried out and it is possible to detect, for example, an improper air or water arrival in the plasma vessel. 3 figs