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现代电子图象管主宰了高速摄影技术的最新进展。基本上,这些管子都用一个光电阴极,将光学图象变换成电子图象,然后,电子加速打到荧光屏上,再变成光学图象,进行照相记录。电子束可以放大和控制,产生许多效应:它可以用作快速光学快门,可以产生巨大的光放大,也可以产生运动图象的显示,如电影式序列和条纹记录。最简单的图象管采用近贴聚焦,使光子产生的电子打到荧光屏上。当用光纤面板把图象传送到记录胶片上时,这些管子可产生中等的光放大。在光电阴极和荧光屏之间放置微通道板(简称MCP)——一种电子图象倍增器阵列,可产生大得多的光放大(10~5×)。更复杂的管子应用了静电或磁聚焦系统,使光电子成象到远处的荧光屏上。而且,可在一个或二个方向上偏转电子束,使产生条纹记录或电影式的图象序列。
Modern electronic image tubes dominate the latest advances in high-speed photography. Basically, all of these tubes use a photocathode to convert the optical image into an electronic image, which is then accelerated onto the screen and converted into an optical image for photographic recording. The electron beam can be amplified and controlled to produce many effects: it can be used as a fast optical shutter, can produce huge optical magnifications, and can also produce moving image displays such as movie sequences and stripe recording. The simplest image tube uses near-focus focusing, so that electrons generated by photons hit the screen. These tubes produce moderate light amplification when the image is transferred to the recording film using a fiber optic faceplate. Placing a microchannel plate (MCP) between the photocathode and the phosphor screen, an array of electronic image multipliers, produces a much larger optical magnification (10-5x). More sophisticated tubes use electrostatic or magnetic focusing systems to image the photoelectrons onto distant screens. Also, the electron beam can be deflected in one or two directions to produce a stripe record or a movie-like image sequence.