To truly optimize TEM and STEM imaging, EDX and EELS may require acquisition of different signals at different accelerating voltages. The rules may vary from sample to sample but, it is generally accepted that: 1) the best imaging is done at the highest possible accelerating voltage above which visible damage will occur, 2) EDX, especially when mapping, benefits from lower voltages with increased ionization cross-sections, thus yielding better signal-to-noise ratio maps for a given total dose, and 3) EELS works best at high voltages to avoid multiple scattering, which degrades the EELS signal with increasing sample thickness.

Built on an ultra-stable foundation

The Spectra Ultra S/TEM is delivered on a platform designed to offer an unprecedented level of mechanical stability quality through passive and (optional) active vibration isolation.

Like the Thermo Scientific Spectra 200 S/TEM and Spectra 300 S/TEM, the system is housed in a fully redesigned enclosure with a built-in on-screen display for convenient specimen loading and removal. For the first time, full modularity and upgradeability can be offered between uncorrected and single-corrected configurations with variable heights, allowing maximum flexibility for different room configurations.