| 摘要 |
<p>The invention relates to a tunable magnetron having coaxial cathode and anode systems (13 and 11, 12) which between themselves define an annular, in operation evacuated interaction space (18) and a rotatably arranged tuning body (20, 24) supported by two rolling bearings, suitable ball bearings (21, 22). The tuning body (20, 24) with its bearings (21, 22) is situated in an evacuated space (25) communicating with the interaction space (18), and a magnetic circuit having two pole shoes (16, 17), situated one on each side of the interaction space for producing an axial magnetic field through the interaction space (18), is closed through the rolling bearing (21) situated closest to the interaction space. In order to prevent magnetic interaction forces between the rolling bodies from influencing the rotation in the case of continuous operation, in particular if the bearings have no retainer ring, at least the rolling bodies in the bearing (21) situated closest to the interaction space (18) are made of non-magnetic material, e.g. non-magnetic hard metal or ceramic material.</p> |
