title: Brightness measurement of an electron impact gas ion source for proton beam writing applications.
abstract: We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators.
authors.affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542.
authors.forename: N
authors.initials: N
authors.lastname: Liu
authors.affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542.
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542.
authors.forename: R
authors.initials: R
authors.lastname: Pang
authors.affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542.
authors.forename: P Santhana
authors.initials: PS
authors.lastname: Raman
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583.
authors.forename: A
authors.initials: A
authors.lastname: Khursheed
authors.affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542.
authors.forename: J A
authors.initials: JA
authors.lastname: van Kan