Posted on by maxfomitchev

I have connected a Ketek AXAS SDD detector (Fig. 1) to an MCA-PRO 16 system and calibrated the spectrometer using a Fe-55 source (Fig. 2) purchased from Imagesco.

Fig. 1. Ketek AXAS SSD detector.
Fig. 2. 55Fe and 57Co calibration sources.

The resulting 55Fe calibration spectrum is shown on Fig. 3. 5.9 keV line width is 150 eV (2.5% FWHM).

Fig. 3. 55Fe spectrum captured using Ketek AXAS SDD detector.

57Co calibration spectrum is shown on Fig. 4. The 6.4 keV line is split and the 14.4 keV line appears right on the mark, confirming the expected near-perfect linearity of the silico drift detector.

Fig. 4. 57Co spectrum captured using Ketek AXAS SDD detector.

Conclusion

57Co source is a better choice than 55Fe for calibrating silicon drift x-ray detectors. The 57Co source provides two far-spaced peaks (6.4 and 14.4 keV) that allow establishing / verifying calibration linearity over virtually the entire 1 to 20 keV range of the silicon drift detector (SDD).