The new Oxford scanning proton microprobe analytical facility

Abstract

A purpose-built scanning proton microprobe facility has been established for multidisciplinary research at the University of Oxford. 1-3.8 MeV beams of protons with currents of up to 150 pA focused into submicron-sized probes can now be obtained for production of high-resolution PIXE and BS maps of samples from a wide range of applications. This article briefly describes the system hardware as well as results achieved during the commissioning stage of the facility. Further development work is now directed towards achieving 100 nm probes and, as part of this work, a novel quadrupole lens has been developed which, when used in a doublet or triplet system, achieves submicron resolution. Measurement of the aberrations of these quadrupoles, using the grid shadowmethod, showed negligible parasitic aberration below fifth order. The results are compared to similar measurements performed on the quadrupoles of the original probe-forming lens system. © 1989.