Saturation in Continuous Channel Electron Multipliers

The steady state gain of electron space current in straight continuous channel electron multipliers is calculated. Ion feedback and space charge effects are neglected, but variation of secondary yield with primary energy and increased wall conductivity due to electron bombardment are considered. Saturation occurs when enough wall current is converted to space current so that the reduced electric field diminishes the effective secondary yield to unity. Predicted results are in good qualitative agreement with reported observations.