A new thermo-desorption laser-heating setup for studying noble gas diffusion and release from materials at high temperatures

Abstract

A new heating and gas treatment line for Thermo-Desorption Spectrometry (TDS) of noble gases (He, Ne, Ar, Kr, and Xe) is presented. It was built with the primary objective to offer advanced temperature controls and capabilities while working in a cold environment. By choosing a high-power continuous wave laser as the heating source and using a proportional-integral-derivative controller system, TDS of noble gases can now be performed with fast and highly steady heating ramps (e.g., less than 1 °C deviation from the set point for ≤1 °C s-1 ramps). Sample temperature over 2000 °C can also routinely be reached, with limited heating of the sample support and the sample chamber, offering the possibility to have several samples awaiting in the ultra-high vacuum chamber. We also present the development efforts made to increase temperature homogeneity of the heated sample while limiting the contact with the sample holder. Recent results acquired with this TDS setup on krypton thermal diffusion in uranium dioxide (UO2) as a function of O2 additions are also presented as an application example.