Recent and future developments in low power total reflection X-ray fluorescence spectroscopy

Today, energy-dispersive X-ray fluorescence (EDXRF) spectroscopy with low power X-ray tubes and thermoelectrically cooled detectors provide analytical performance which in the past was restricted to systems with kW power X-ray tubes and liquid nitrogen cooled Si(Li) detectors. Especially for low power TXRF spectrometers, the sensitivity could be improved by an order of one magnitude in the last 5 years. This progress was mainly based on improvements in quantum efficiency of all components and less on high power excitation sources. developments caused further improvements in the analytical sensitivity as well as in the analytical performance. troduction of a micro-focus X-ray tube increased the excitation power by a factor of 1.3. An additional improvement could be achieved by optimizing the detector window design. By optimizing the detector entrance geometry, the solid detection angle of a silicon drift detector (SDD) was increased by a factor of 1.8. In addition, the recent development of a new generation of silicon drift detectors increased the active detector area by a factor of three enhancing the peak to background ratio by a factor of two. Furthermore, the high-energy efficiency of this new detector type was significantly improved. esult of all these improvements the detection limit for nickel could be decreased to a value of 1 pg.