Development of a compact single ion microprobe

A compact single ion microprobe has been developed for the examination of t he microscopic characteristics of sensors, particle detectors and other dev ices used for fusion diagnostic systems. The microprobe has been constructe d by use of commercially available standard components and can be easily re composed according to beam requirements for various irradiation experiments . The beam size and position were successfully measured by use of a beam se nsor with a quadrant-type electrode. Furthermore, the automatic beam contro l and adjustment were accomplished by a feedback system in obedience to a c omputer program based on a modified SIMPLEX iterative method. Some experime nts for the examination of the performance of the microprobe were done by u se of several elaborate beam detectors and indicated that a beam of a singl e ion (one ion in one pulse), 1ns in pulse width and 2.5 mu.m in diameter c ould be successfully produced by the present microprobe.