LAMBDA with High-Z sensor is well suited for energies above 20 keV
We have developed versions of the LAMBDA system where the Silicon sensor is replaced with one of the “high-Z” materials – Gallium Arsenide (GaAs) or Cadmium Telluride (CdTe). These provide greater detection efficiency at high X-ray energies. The result:
- zero noise
- high spatial resolution
- high speed
The 2,000fps readout of a high-Z LAMBDA system is more than 1,000 times faster than a typical flat-panel detector. This allows time-resolved hard X-ray experiments on millisecond timescales.
Sensor material: Gallium Arsenide or
As shown in the photoelectric absorption graph, Cadmium Telluride has higher quantum efficiency than Gallium Arsenide at higher X-ray energies. This makes CdTe the natural choice for experiments at 60keV and above.
However, CdTe strongly re-emits fluorescence photons around 25–30keV when illuminated with higher-energy photons. This can reduce the detected signal and slightly blur the image.
So, GaAs is beneficial in the 25–50keV range. After flat-field correction, GaAs sensors also deliver better image uniformity.
If you’re considering using high-Z material, get in touch and we’ll find the best solution for your experiment.
Depending on the sensor material the following specifications are valid:
| ||Si ||GaAs ||CdTe |
|Recommended option by energy range ||6 – 24keV ||8 – 75keV ||8 – 150keV |
|Extended energy range ||6 – 25keV ||25 – 50keV ||50keV+ |
|Adjustable threshold range ||4 – 40keV ||5 – 50keV ||5 – 75keV |