| 摘要 |
<p>PURPOSE:To make it possible to maintain the interval between a cathode and a G1 electrodeconstant in the operation by forming the cathode structure with materials of different thermal expansion coefficients respectively. CONSTITUTION:The cathode structure consists of a cathode frame 6, a holder 9, a bead glass 8, and a G1 electrode, the frame 6 is connected to the holder 9 through a tongue piece 11, and the holder 9 is fixed to the bead glass 8. By the heat generated when the cathode is operated, the members to form the structure are deformed thermally. The interval between the cathode 1 and the G1 electrode is in creased by the thermal expansion of the G1 electrode and the tongue piece 11, for example, but it is reduced by the thermal expansion of the holder 9 and a cathode sleeve 3. As a result, by combining the materials of members with different thermal expansion coefficients respectively, the distance between the cathode and the G1 electrode can be made constant in a short time after the cathode operation is started.</p> |
