| 摘要 |
PURPOSE:To provide a beam indexing tube which can realize sufficient output of electric signals by use of a solid photoconverter element having a considerably smaller light-receiving area than a photomultiplier tube. CONSTITUTION:After the inner wall of a funnel 1 is conated with a graphite film 13, an aluminum vapordeposition film 10a is provided on the film 13. The surface of the aluminum film 10a is wavy due to graphite particles. Light emitted from an index phosphor stripe 5 is reflected by a reflecting diffusing surface, the surface of the fim 10a, and is diffused as reflected light 8a in every direction. By the means mentioned above, the total amount of light incident upon a photoconverter element 11 aftet passing through a lighting window 12, that is to say, light emited from the phosphor stripe 5 and becomes directly incident upon the element 11, and the reflected light 8a just passing through the window 12 after being diffused in every direction at every point of the above reflecting diffusing surface becomes sutable and relatively large almost irrespective of the position of the electron-beam scanning. |
