Ultra high vacuum high precision low background setup with temperature control for thermal desorption mass spectroscopy (TDA-MS) of hydrogen in metals

• UHV high precision low background setup for hydrogen TDA is developed.
• Low thermal capacity enables precise temperature control and rapid cooling, high number.
• Limit of detection for hydrogen is 5.9×10−3 µg g−1.
• Allows precise thermal desorption mass spectroscopy, traps quantification.

In this work, a newly developed UHV-based high precision low background setup for hydrogen thermal desorption analysis (TDA) of metallic samples is presented. Using an infrared heating with a low thermal capacity enables a precise control of the temperature and rapid cool down of the measurement chamber. This novel TDA-set up is superior in sensitivity to almost every standard hydrogen analyzer available commercially due to the special design of the measurement chamber, resulting in a very low hydrogen background. No effects of background drift characteristic as for carrier gas based TDA instruments were observed, ensuring linearity and reproducibility of the analysis. This setup will prove to be valuable for detailed investigations of hydrogen trapping sites in steels and other alloys. With a determined limit of detection of 5.9×10−3 µg g−1 hydrogen the developed instrument is able to determine extremely low hydrogen amounts even at very low hydrogen desorption rates. This work clearly demonstrates the great potential of ultra-high vacuum thermal desorption mass spectroscopy instrumentation.

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