Detector for detecting low-energy electrons

摘要

The invention relates to a detector for detecting low-energy electrons. It has a layer of a material which is capable of scintillating and which emits a light pulse upon the impingement of an electron. A device for registering the light pulses and converting them into electrical charge pulses is optically coupled to the scintillation layer. The aim of the invention is a detector which has a high detection probability for the low-energy electrons and a low detection probability for X-rays, may be used in ultra high vacuum and allows the sample temperature to vary within wide limits. According to the invention, the scintillation layer has a thickness of 0.2 to 10 mu m for this purpose and the device for registering the light pulses has a dark-count rate of at most 50 pulses per second. On the side facing the incident electrons a further thin layer is provided of a material made from elements with low atomic number of a thickness of 30 to 40 nm and, on this, a thin carbon layer with a thickness of 10 to 20 nm.