STUDY ON THE STABILITY OF CHANNEL ELECTRON MULTIPLIERS

A method to test the stability of high lead glass CEM is made and some results are obtained. The life test datum with an accumulative count about 1011 is obtained; The stru-cture and composition of active surface of fatigued CEM are analyzed by using AES. We find the increase of carbon on the active surface is the main cause for the decrease of the CEM gain through the life test. The thicknese of contaminating carbon layer is approximately 50. In order to improve CEM s bake-resisting property, we have also studied theeffects of the baking temperature on the gain and FWHM, and the relationhip between the baking temperature and the reduction temperature. we find, on condition of keeping the resistivity constant at a certain time, the higber the reduction temperature, the higher the bake-resisting temperature is.