Comparison of deuterium retention in tungsten exposed to deuterium plasma and gas

TL;DR

This study compares deuterium retention in tungsten exposed to plasma and gas, revealing significant differences in retention amounts, desorption temperatures, and detrapping energies, which are crucial for fusion material applications.

Contribution

It provides a direct comparison of deuterium retention behaviors in tungsten under plasma and gas exposure, highlighting differences in retention capacity and thermal release characteristics.

Findings

Plasma exposure results in higher deuterium retention than gas exposure.

Gas-charged tungsten shows higher desorption temperature than plasma-exposed tungsten.

Detrapping energies differ significantly between the two exposure methods.

Abstract

Deuterium(D) retention behavior in tungsten(W) exposed to deuterium plasma and gas was studied by means of thermal desorption spectroscopy (TDS): deuterium plasma exposure in which W was exposed to D plamsa with 35 eV/D at 393 K to the fluence of 3.8E24 D/m2; D2 gas charging in which W was exposed to D2 gas of 500 kPa at 773 K for 4 hours. TDS shows that the total D retention in plasma exposure W is 1.00E22 D/m2, one order of magnitude higher than that of gas charging W; however, the D2 desorption peak of gas charging W is 952 K, much higher than 691 K of plasma exposure W. The detrapping energies of deuterium were determined experimentally from the measured peak temperatures at different heating rates and were found to be 2.17 eV for gas charging W and 1.04 eV for plasma exposure W, respectively.