Facility description
The MIT Electron Microprobe Facility was established in 1972 and has been constantly upgraded. Initially, it had a MAC-5 electron microprobe. In 1984, a JEOL JXA-733 Superprobe was purchased with National Science Foundation, Earth Sciences: Instrumentation and Facilities (NSF-EAR I&F) and Keck Foundation funding, and in 1992, a second JEOL JXA-733 was added with funds from NSF and MIT. In 1997, we obtained funding from the NSF-EAR I&F program to carry out a major upgrade for our JEOL instruments. The upgrade was purchased from Geller Microanalytical Lab, and included new automation for the wavelength dispersive spectrometers (WDS) and stage, new quantitative analysis and data reduction software, new digital imaging and stage mapping software, and new electronics and control software for the energy dispersive spectrometer (EDS). In 2005, we upgraded the automation hardware of both instruments by replacing the old Tracor-Northern PAC controllers with control hardware from Geller Microanalytical Lab with funding from the NSF-EAR I&F program.
In 2009, we obtained funding from NSF-EAR I&F to replace one of the old and frequently malfunctioning JXA-733s with a state-of-the-art JEOL JXA-8200 Superprobe. This upgrade was completed in 2010 with NSF and MIT funding. The other JXA-733 was kept in operation until 2018, but is now retired. The JEOL JXA-8200 Superprobe features a LaB6 electron gun that generates higher beam currents with smaller spot size compared to conventional W electron guns. New WDS spectrometer design and highly sensitive WDS analyzing crystals and detectors allow accurate trace element analysis. The instrument also features the advance xClent II cathodoluminesence system that has wavelength discrimination capability allowing map acquisition at different light wavelengths and spectroscopy for phase characterization and identification of trace impurities.
