| 摘要 |
In a radiation-sensitive semiconductor element which is divided into a number of sub-elements, the surface potential in the sub-elements varies with incident radiation as a result of charge carriers generated by the radiation. As soon as an adjustable threshold value of this potential is reached in one or more of the sub-elements, a current starts to flow which is signalled by means of a detector and a detection unit. Because the speed of reaching the threshold value depends on the intensity of the radiation, the time measured between the adjustment of the threshold value and the signalling of the current is a measure of the radiation intensity. By means of such a semiconductor element, the associated detection unit and extra electronics, if any, the energy or the cross-section of a beam can be determined and be readjusted, if necessary. Such a semiconductor device can also be used very readily for focusing, for example in VLP apparatus.
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