Low-energy ion source characteristics for producing an ultra-fine microbeam

A duoplasmatron-like ion source which produces a mixed beam of low-energy ions and electrons in high vacuum has been developed to be used as an incident ion beam to the ion microbeam system using acceleration lenses, to obtain a beam diameter of the order of 0.1 mu m. Energy spreads of the extracted beam of H-2(+) and Ar+ ions of several tens eV were evaluated to be within 2 eV by using a uniform electric-field type energy analyzer. The ion beam, thus obtained, satisfies the requirements for producing the above-mentioned ultra-fine microbeam.