Design of a high-efficiency short-pulsed positron beam system

A conceptual design of a new pulsing system for slow positron beams is described. Although the principle resembles the conventional pulsing system using rf power, the present method applies ideal waveform to the moderator for adjusting the time-of-flight of positrons using a fast arbitrary waveform generator. Requisites for the new design are the monochromaticity (less than about 1 eV) of the initial dc positrons and the ultra-fast precise waveform to be applied to accelerate the positrons. It is shown that these requisites are within the present status of art of positron technology and electronics. A preliminary result on the monochromaticity of the positron beam is also presented.