Fabrication of microsphere plate electron multiplier device

摘要

The microsphere plate (MSP) is a new type of electron multiplier device which was developed by El-Mul Technologies Ltd (Israel) . It is similar to the traditional microchannel plate (MCP) in dimensions and model of operation. However, different to the fabrication process for the traditional glass MCP, the MSP is formed by sintering glass beads of 20 to 100 μm in diameter into a glass plate, and the sintered glass beads form an irregularly tortuous channel for electrons to transport. After the formation of the dynode and the electrode, the MSP were fabricated successfully. By applying a DC voltage (1500-3500V, depending on the thickness of MSP) on the electrodes which located on the two faces of MSP, a high electron gain can be obtained. Comparing with MCP electron multiplier, the MSP electron multiplier have the following unique advantages: (1) the fabrication process is easy and the fabrication cost is low; (2) the tortuous channel between glass beads can impede the ion of output-face feedback to the input-face of MSP, thus MSP has no ion-feedback; (3) as there is no ion-feedback, the operating vacuum limitation can be decreased. So the MSP is widely used in particle-imaging, time-of-flight mass spectroscopy, particle counting, ion-beam monitoring, electron microscopy, UV and X-ray imaging, and in photomultipliers.