Recently, researchers from the Institute of Plasma Physics, Hefei Institutes of Physical Science of the Chinese Academy of Sciences, in collaboration with ITER organization and the Southwest Institute of Physics (SWIP), carried out a study on the isotope effects of mixed plasma-driven co-permeation based on the first wall of Chinese Helium Cooled Ceramic Breeder (HCCB) test blanket module (TBM), which is made of CLF-1 Reduced Activation Martensitic/Ferritic (RAFM) steel.
TBM program is to test the validations of tritium (T) breeding rate predictions, recovery process efficiency and inventories in blanket materials. However, the plasma-driven permeated T may be mixed into the T produced from the intended Li (n, T) He reactions between the fusion neutrons and the breeding material, thus significantly affecting the assessment of TBM's breeding rate. Meanwhile, the first wall of TBM will be exposed to deuterium (D)–T mixture plasma, it is necessary to consider the isotope effects on plasma-driven co-permeation as well.
In this research, researchers simulated the deuterium–tritium (D–T) plasma with hydrogen (H)-D mixture plasma. They found that the mixed plasma-driven co-permeation still obeyed the classical mass effects, and the mass effects remained basically constant at different temperatures and particle incidence energies.
At the same time, the existence of hydrogen provided additional channels for D recombination, thus decreasing the D steady state permeation flux.
The transient and steady-state permeation behaviors of mixed plasma-driven co-permeation are investigated in detail.
The data in this study can be used to predict the tritium permeation through the first wall of ITER TBM and support the evaluation of tritium permeation in future fusion reactors.
The transient behaviors of mixed plasma-driven permeation. (Image by LIU Caibin)
The steady state behaviors of mixed plasma-driven permeation under various exposure conditions. (Image by LIU Caibin)
Other image from ITER website
