| 摘要 |
A focusing device for an electron tube is constituted by alternating magnets and pole pieces in the form of washers, which are fixed against one another in such a way as to form a cylinder surrounding the envelope of the tube and being of the same axis as the latter, the electron beam propagating along said axis. The magnetized washers have a central hole and are interrupted over part of their circumference by an opening permitting their fitting between the pole pieces previously fixed to the envelope.
|
