| 摘要 |
A plasma mass filter for separating low-mass particles from high-mass particles in a multi-species plasma includes a cylindrical shaped wall which surrounds a hollow chamber. A magnet is mounted on the wall to generate a magnetic field that is aligned substantially parallel to the longitudinal axis of the chamber. Also, an electric field is generated which is substantially perpendicular to the magnetic field and which, together with the magnetic field, creates crossed magnetic and electric fields in the chamber. Importantly, the electric field has a positive potential on the axis relative to the wall which is usually zero potential. When a multi-species plasma is injected into the chamber, the plasma interacts with the crossed magnetic and electric fields to eject high-mass particles into the wall surrounding the chamber. On the other hand, low mass particles are confined in the chamber during their transit therethrough to separate the low-mass particles from the high-mass particles. The demarcation between high-mass particles and low mass particles is a cut-off mass M c which is established by setting the magnitude of the magnetic field strength, B z, the positive voltage along the longitudinal axis, V ctr, and the radius of the cylindrical chamber, "a". M c can then be determined with the expression: M c = ea2(B z)2 / 8V ctr.
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