The energy resolution realized by the spectrometer is the most crucial overall factor in electron energy loss spectroscopy.
NION Company (Kirkland, Washington, United States) is pioneering the way, thanks to the 4 meV energy resolution achieved by the NION IRIS EEL spectrometer. This energy resolution is an unrivaled lower limit that is yet to be matched by other manufacturers.
To further push the performance of the EELS spectrometer, the instrument can be best integrated with a direct electron detector improved for a high dynamic range, speed, and sensitivity.
DECTRIS has developed a new direct electron detector called ELA, based on its latest EIGER2 technology and a sensor format that is adapted to the need of an electron spectrometer.
DECTRIS’ hybrid pixel detectors can count electrons quite efficiently, and can manage probe currents well over 100 pA, as usually required in STEM-EELS experiments.
The DECTRIS ELA detector is fitted with a Si sensor and can be operated at 9000 spectra/second between 30 and 200 keV in continuous readout mode. Its improved parameters enable elemental mapping virtually in real-time and allow to record momentum-resolved EEL spectra in just a few minutes.
- DQE ~ 0.8 (with no super-resolution)
- PSF @ 100 keV ~ 1.3 pixels, more improved at lower keV
- 2,250 full frames/second and faster for sub-areas
- Dynamic range >106:1
- Improved for 30–200 keV operation
- While counting individual electrons, users can utilize a beam current of greater than 100 pA
- Elemental mapping
EELS of hexagonal boron nitride (h-BN), E0 = 100 keV, beam current = 170 pA, 10-second exposure, 0.28 eV/ch. Raw data (no dark subtraction or gain normalization). Image Credit: N. Dellby. T.C. Lovejoy et al., unpublished (2019). Image credit: Dectris Ltd.
Specifications of ELA
Table 1. Source: DECTRIS
|Pixel size [µm²]
||75 x 75
|Number of pixels
||1028 x 514
|Active area, width x height [mm²]
||76.4 x 38.6
|Energy range [keV]
||30 - 200
|Maximum frame rate, ROI [Hz]
|Maximum frame rate, full frame [Hz]
||2'250 (16-bit), 4'500 (8-bit)
||Water, 20 °C
|Dimensions (WHD) [mm³]
||110 x 80 x 260
|Detective Quantum Efficiency, DQE(0)
||0.9 @ 100 kV; 0.8 @ 200 kV
|Radiation hardness [el./mm²]
||>5 x 10¹⁸
All specifications are subject to change without notice.