| 摘要 |
: PARTIAL PRESSURE GAUGE USING A COLD-CATHODE ION SOURCE FOR LEAK DETECTION IN VACUUM SYSTEMS The partial pressure gauge consists of a combination of a magnetically confined cold-cathode discharge for the ionization of the residual gas in a vacuum system (ion source) and the magnetic separation of the ion masses (mass spectrometer). A suitable inhomogeneous magnetic field configuration is instrumental in producing such a discharge that the energy spread of the ions is sufficiently small, which in turn guarantees the resolution required for mass separation in partial pressure measurements (for purposes of leak detection). The ions are accelerated solely within the electric field of the discharge. The special shape of the cold-cathode discharge influences the electric field in such a manner that the energy of the emitted ions is low and remains virtually independent of the potential applied to sustain the discharge. Due to the low ion energy a moderate magnetic field suffices for the mass separation. Hence, the mass spectrometer and the ion source can be integrated within the same magnetic field assembly.
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