The Manitoba automated high-energy proton microprobe (MA-HEM) and its application to research in the geological and biological sciences

A high-energy (40 MeV) transmission proton microprobe is now operational at the University of Manitoba Accelerator Laboratory. It uses the spiral ridge cyclotron as particle source. All elements of the probe and its associated beam transport system were constructed, assembled and tested at the laboratory. The beam spot size is somewhat in excess of 10 μm diameter at this time with beam on target in the region of 300 pA. This microprobe is designed to exploit features not available to microprobes operating at a few MeV incident proton energy. MA-HEM is a microscope able to examine the details of elemental composition of geological samples at the inclusion level, biological samples at the cellular level and physical materials at the micron level. Comments on the future development of custom-made proton microprobes are made, and several problems identified. (orig.)