| 摘要 |
PURPOSE:To prevent any fusing cement molten from fixing on the inner wall and the end surfaces of an emission tube during the time when the said tube and electrode conductors are fused, and prevent any crack which might be developed in the said tube by providing the electrode conductor with a large and a small diameter part. CONSTITUTION:Electrode conductors 9 and 10, the ends of which are provided with electrodes 6 and 7, are fused to the inner wall of the end parts of an emission tube 1 made of light transmitting single crystal alumina by use of fusing cements 4 and 5. The electrode conductors 9 and 10 have large diameter parts 11 and 12, which are fused to the inner walls of the end parts of the tube 1, and small diameter parts 13 and 14, the outer surfaces of which are at least 0.2mm. distant from the inner walls of parts of the tube 1 which are near the end surfaces of the tube 1. As a result, during the time when the tube 1 and the electrode conductors 9 and 10 are fused, the fusing cements 4 and 5 are not fixed on the end surfaces of the tube 1 as well as on the inner walls of parts of the tube 1 which are near the end surfaces of the tube 1. |
