Towards soft x-ray fluorescence measurements in the laboratory using a laser-produced plasma source and a complementary metal-oxide semiconductor detector

Abstract

With the advent of commercially available CMOS technology suitable for direct detection of photons in the soft X-ray range, new possibilities are opening up for the improvement and optimization of experiments requiring energy discrimination capabilities in this energy range. SDDs are widely used as energy-dispersive detectors, but they cannot be used with pulsed sources due to the overwhelming temporal photon density. Wavelength-dispersive solutions offer unmatched energy resolution, but suffer from low detection efficiency and a limited energy bandwidth which can be monitored. The use of common CCDs as energy-dispersive detectors in this energy range is limited by their energy resolution and especially their readout speed, which can result in significant experimental dead time and limits the usable frequency of pulsed sources. Therewhile, CMOS detectors with high energy resolution and high frame rates are an efficient, versatile and cost-effective alternative as detectors for pulsed sources. In this work we present the characterization of a commercially available, backside-illuminated CMOS detector regarding its energy resolution and quantum efficiency at the BESSY II synchrotron radiation facility with a well-known soft X-ray radiation source. Furthermore it is used in a proof of principle XRF measurement with a laboratory-based laser-plasma source.