Influence of Preliminary Irradiation by a High Heat Flux on the Re-emission and Thermal Desorption of Deuterium Implanted from Reduced Activation Steels

Abstract

The deuterium release from reduced activation Eurofer steel samples is investigated by measuring the re-emission directly during ion irradiation and via thermal desorption spectroscopy without contact with air. A part of the experiments are carried out using a sample previously subjected to high-power pulsed thermal action using the QSPA-T setup, Troitsk Institute of Innovative and Thermonuclear Research. Subsequent irradiation is performed using a 5-keV D₃⁺ ion beam to a fluence of up to 10²¹ m^–2 at room temperature. In all cases, a major part of the implanted deuterium is released from the sample already at the irradiation stage. A significant part of the deuterium also desorbs in the interval between irradiation and spectroscopic measurements. Deuterium re-emission from damaged samples reaches a maximum value more slowly than that from undamaged ones, and deuterium release during holding is more intense. This can be explained by the structure of the damages caused by the heat flux: the hydrogen-trap concentration grows in the material, and the surface area participating in desorption increases.