The CSIRO-GEMOC nuclear microprobe: a high-performance system based on a new closely integrated design

A new Nuclear Microprobe (NMP) has been developed at the CSIRO, in collaboration with GEMOC and the University of Melbourne, to better exploit advanced techniques that are unique to the NMP, as a complement to the developing range of microanalytical techniques available in geology. The new probe uses a new design that closely integrates the beam forming lens system with the chamber, microscope and detector systems to provide good focussing performance, a normal viewing microscope and large solid-angle detectors. The key to this design is a new quadrupole quintuplet lens system which uses a new design for each quadrupole, with pole-tip extensions and yoke cut-outs for detectors, permitting an effective working distance of 80 mm and unrestricted access for detectors at 135°. Further features of the new probe include: large area X-ray, γ-ray and particle detectors, digital signal processors, electrostatic on-demand beam-switching and scanning, Questar long-range microscope, computer-controlled sample goniometer, sample-change vacuum-lock, anti-vibration mounting and efficient beam shaping using computer-controlled object and divergence limiting slits.