Technical assessment of a thermal desorption spectroscopy apparatus for plasma facing components

The characterization of hydrogen isotope retention and helium-vacancy clustering in plasma-facing materials (PFMs) is essential for the development of long-pulse magnetic confinement fusion devices. This paper provides a technical description of the Thermal Desorption Spectroscopy (TDS) facility located at the ENEA Frascati research center, which has been upgraded to support the study of metallic PFMs in the context of the EUROFusion research program. Originally designed for carbon-based materials, the apparatus has been reconfigured for investigating gas retention and desorption kinetics in plasma-facing materials, focusing on exploration of high-temperature regimes. A primary technical feature of the system is the implementation of an induction-based heating architecture that enables sample temperatures exceeding 1200 °C, thereby surpassing the thermal limitations of conventional resistive TDS systems. The paper details the vacuum architecture, sample transfer system, RF induction heating setup, temperature and pressure diagnostics, quadrupole mass spectrometer (QMS), and the integrated data acquisition framework. Standard operating and calibration procedures for temperature, pressure, and QMS sensitivity are presented together with background characterization to quantify measurement reliability and uncertainty. Finally, representative application cases are used to demonstrate the current performance of the apparatus in both total gas inventory measurements and desorption peak analysis up to 1600 °C, with a nominal maximum temperature of 2000 °C expected in upcoming experimental campaigns. The resulting characterization defines the present operating conditions of the facility and provides the experimental basis for future high-temperature investigations of plasma-facing components.