Ultra High Energy Resolution Electron Spectrometer for Atomic Resolution Studies

If the energy resolution of electron energy loss spectroscopy carried out in an electron microscope, with an atom-sized electron probe, could be improved to 10 meV or better, a new way of studying materials at the atomic scale, by recording and analyzing their vibrational energies, would become possible. The energy resolution attainable with present-day monochromated electron microscopes and spectrometers is about ten times too poor for such studies. Nion Company is now building a monochromator that will achieve the required performance. This proposal requests funds for designing and building a spectrometer able to record electron energy loss spectra with a matching energy resolution. We will design and build and all-magnetic Ultra-High Energy Resolution Electron Spectrometer(UHERES) that will deliver an energy resolution of ~10 meV at 100 keV primary and ~5 meV at 40 keV. The spectrometer will work together with the new monochromator and the Nion UltraSTEM electron microscope, which will illuminate the sample with an atom-sized electron beam. Commercial applications and other benefits: Determining the energies of vibrational modes experimentally will open a fundamentally new window on the study of atomic arrangements at interfaces, grain boundaries, point defects and surfaces. Elements as light as hydrogen are likely to become detectable, and their bonding arrangements easily determined from the observed vibrational energies. Being able to determine the positions and bonding of light atoms is especially important for understanding and designing energy conversion and storage devices needed for a green economy. The new spectrometer and the associated equipment (a complete monochromated scanning transmission electron microscope) will open up a new market segment in research instrumentation, which we estimate will be worth about $20M per year for Nion.