Canal structure of an electron multiplier

Abstract

A canal structure of an electron multiplier, especially for an X-ray image intensifier, comprises several perforated metal dynodes which emit secondary electrodes and between each of which a plate-shaped separating element of electrically insulating material with an at least largely regular hole pattern is arranged. This canal structure has a relatively simple design, in which undesirable charging up at the separating elements is prevented to a large degree. The metal dynodes are realized as impingement dynodes of thin perforated foils or screens or nets or grids, where at least four holes each fall on the area occupied by a canal-like hole of the plate-shaped separating element. The plate-shaped separating elements have a comparatively greater thickness than the thickness of the perforated foils or screens and have on their upper and lower flat sides a layer of electrically highly conductive material and have at their hole walls a layer of an electric resistance material.