Measurement of Energy Distribution of Output Electrons From a Microchannel Plate Based on Vacuum Photodiode

Abstract

The energy distribution of output electrons (EDOE) from a microchannel plate (MCP) is measured using electrons emitted by a vacuum photodiode excited by a 266 nm Ti-sapphire femtosecond laser. The photoelectrons emitted from the photocathode are focused on a specific location of the MCP by a magnetic lens. While exist an enough voltage difference between the two ends of MCP, the energy distribution curve of output electrons form MCP can be obtained by analyzing the data as function of the bias voltage applied to the charge collector. The result shows that the energy distribution curve obtained by this means consists of a sharp and a long tail when using pulse light source. The most probable electron energy (MPE) is 12.64 eV and the full width at half maximum (FWHM) of the energy distribution curve is about 29.23 eV while the applied voltage difference is 700 V in the experimental setup. The MPE is 10.63 eV and the FWHM of the energy distribution is 22.436 eV in simulation. The measured curve is consistent with the expectation from simulation.

Keywords

• Measurement
• microchannel plate
• output electron
• energy distribution
• vacuum photodiode