5.1.1.2 EDXRF spectrometry

The development of semiconductor detectors in the 80's opened the possibility of EDXRF spectrometry.

With an EDXRF system a spectrum containing the characteristic lines of different elements is acquired virtually simultaneously, and the measurement time is comparatively lower than that required for WDXRF spectrometers. The possibility of measuring a non-collimated x-ray fluorescent beam makes the EDXRF overall sensitivity larger, and small power tubes can be used for excitation.

The figure below depicts the main components of an EDXRF spectrometer from the 90's. EDXRF spectrometers initially were based on the use of Si(Li) detectors, requiring liquid nitrogen cooling for operation. With the development of mechanically cooled detectors the Si(Li) detectors are less and less used. Another major milestone in the development of EDXRF spectrometers was the substitution of analog electronic processing by digital processing units, much faster in processing the electronic pulses originating from the detector unit. The miniaturization in electronic component design and in x-ray tubes made possible the construction of compact handheld devices with comparable sensitivity.