Emeritus Senior Scientist, Department of Geoscience, University of Wisconsin, Madison
Eugene Cameron Electron Microprobe
Lab
Dept of Geoscience
Weeks Hall Room 306
1215 West Dayton St.
Madison, WI 53706
email: johnf(at)geology.wisc.edu
cell: 608-438-7480
Updated 12/26/2020
I have been using electron probes since 1985: the old MAC at the Geophysical Lab in the mid 1980s, the Smithsonian's ARL-SEMQ 1989-91, Johns Hopkins' JEOL 8600 1991-92, UW's old ARL-SEMQ 1992-93, our Cameca SX51 (1993-today), and now our Cameca SXFive FE.
The electron probe is a "specialized SEM on steroids": its forte is accuracy in microanalysis, because
(1) it explicitly uses standards (so results are not artifically normalized to 100 wt%, thus has built in QC/reality check),
(2) it has very high spectral resolution and can resolve otherwise impossible (by EDS) peak overlaps,
(3) it has low detection limits so trace element measurements are possible in many cases,
(4) we can accurately measure elements as light as B, and
(5) we can accurately measure thin films and coatings either using (a) the multiple voltage technique or (b) low voltages in certain specific cases.
While I officially retired from directing the operation of the electron probes and Hitachi S3400N scanning electron microscope, I continue to be very active with many research projects, some funded by NSF with research scientist Aurelien Moy, on "low kV EPMA". Other projects include chemical peak shifts in Mg, Al and Si Ka X-rays; development of some mineral standards for EPMA; and assorted "problems" in EPMA. A team of myself and 3 colleagues finished a multi-year project to write an uptodate summary of EPMA for Progress in Materials Science (Llovet Moy Pinard Fournelle).