History of EPMA at UW

The UW-Madison Electron Microprobe Lab was established by Prof. Eugene Cameron in 1966 with the purchase of a 3-spectrometer ARL-EMX electron microprobe. Dr. Everett Glover was hired the same year to oversee its operation.

At this time the EPMA technique was relatively new, with the electron microprobe technique first developed by Raimond Castaing’s 1951 PhD thesis and commercialization of the first microprobe in 1958. In the first decade of the technique, there were fewer than 20 instruments in existence or under construction around the world (Duncumb, 2001).

The ARL-EMX at UW-Madison produced early data on lunar materials returned from the Apollo 11 mission, including round robin characterization of a new Fe-Mg-Ti oxide mineral Armalcolite (Anderson et al. 1970).

Anderson et al 1970 Armalcolite

Eugene Cameron UW-Madison EPMA ARL-SEMQ
Eugene Cameron and Everett Glover operating the ARL-EMX Electron Microprobe in the Dept of Geology, Science Hall, UW-Madison

The ARL-EMX instrument operated until 1981 when it was replaced by a 9-spectrometer ARL-SEMQ. Six of the spectrometers were fixed, and the remaining three were tunable. This was the first EPMA instrument installed in Weeks Hall, and the first EPMA with computer data processor.

ARL SEMQ, from Rinaldi and Llovet (2015)

In August of 1993, a state-of-the-art Cameca SX50/51 (SN #485) Microprobe was delivered, with installation of this new generation microprobe continuing into 1994. The SX51 had the same column and electronics as the SXS50, however a key difference was the sub-micron stage, which would become the SX100 (and SX5) stage. Jean-Michel Peneau was the engineer in charge.

In November 1994, Dr. Eugene Cameron “cut the ribbon” on the new SX51 at a ceremony attended by the UW-Geology and Geophysics Alumni Committee.

Cameca SX-51 electron microprobe

In November 2014, a Cameca SXFive field emission (SN #944) Electron Microprobe was delivered. The FE source provides improved targeting ability and stability at low voltage. The SXFiveFE operates with both Cameca PeakSight software and Probe for EPMA/Probe Image software. It is equipped with a Thermo Scientific UltraDry EDS detector running Pathfinder.

John Fournelle operating the new SX-Five-FEG electron microprobe

The lab operates as a multi-user recharge facility, with usage divided between geologists and material scientists and engineers.

The lab was managed from 1966 to 1992 by Dr. Everett Glover (1917-2017), from 1992 to 2020 by Dr. John Fournelle, and since 2020 by Dr. Will Nachlas.