Micro array type electron multiplier as a two dimensional position sensitive detector

A new micro array type electron multiplier working as a two dimensional position sensitive detector has been investigated. As to the structure of the multiplication part, based on micromachining fabrication technique, two types of dynode were designed; one has a pyramid hole type dynode and the other has a slanting hole type dynode. From the simulation result under these dynode structures, it was revealed that more than 10³ would be obtained as the electron multiplication factor if using 12 dynodes. This shows that both devices will have sufficient practical efficiency. Based on these results, both dynodes were produced using micromachining technique; pyramid type dynodes were formed by anisotropic Si etching, and slating type dynodes were molded by a LIGA like process. Using two stages of pyramid type dynodes, we obtained 2.62 as the electron multiplication factor, which well agreed with the simulation result