Remodeling design of commercial transmission electron microscopes to positron–electron transmission microscopes

This paper reports the plans and design of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is remodeled. The kinetic energies of positrons produced by accelerators or by nuclear decays do not have a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic, focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which is used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope.