Impregnated-electrode-type liquid metal ion source

Abstract

An impregnated-electrode-type liquid metal ion source has been developed in which a sintered porous tungsten tip is used. The flow rate of the liquid metal can be controlled by selecting the diameters of the tungsten powders to be sintered (10 and 100 μm). Since the liquid metal can be stably supplied to the tip head, stable operation in a wide range from low (a few μA) to high ion current (a few hundred μA) is possible for various metals such as gallium and gold. Moreover, it is also a potential ion source with liquid metals such as silver with high vapor pressure at the melting point. A new method of holding and directly heating the main component of the ion source by means of knife-edged electrodes with a spring is extremely effective for high temperature operation.