Electron multiplier with high energy electron filter

摘要

An electron multiplier includes a plurality of staggered parallel dynodes disposed between two insulating vanes. The dynodes are disposed between a cathode at one end and a high energy electron filter at the other end. The electron filter includes at least two staggered filter bodies which extend into the space between the vanes. Each of the filter bodies extends slightly more than one-half the distance between the vanes so as to provide no straight path therethrough for high energy electrons, i.e., the filter is optically opaque. Between the dynodes closest to the cathode and the electron filter is a transition region. The transition region includes transition dynodes, having unequal widths and unequal spacings, and steering electrodes. In multiplier operation, the transition region functions to steer low energy electrons around the electron filter.