OPERATIONAL CHARACTERISTICS OF THE IMPREGNATED-ELECTRODE-TYPE LIQUID-METAL ION-SOURCE WITH MULTIPLE TIP AND RESERVOIRS

A new type of impregnated-electrode-type liquid-metal ion source, whic h eliminated the heating problem in the previous source, has been deve loped with multiple tip and reservoirs (TAR's). In the present ion sou rce, the TAR's are connected electrically in series by modifying the T AR holding system. In order to achieve uniform heating of the TAR's, t he materials of the knife-edged electrodes, which introduce the heatin g current to the TAR's, were examined. Tantalum electrodes exhibited b etter results as compared with the conventional Mo electrodes. Both of the two TAR's could be heated up to 700-degrees-C with a heating powe r of 200 W. The maximum indium ion current of 9.1 mA was obtained from the four-TAR source with 40 emission points. Since the present ion cu rrent was limited by the current capacity of the extraction power supp ly, an ion current of more than 10 mA will be expected with a larger p ower supply. The results indicated that an ion current approximately p roportional to the number of the emission points was obtained. This ki nd of ion source could be used as a general ion source in materials sc ience.