Plasma and Fusion Research

Volume 7, 2405074 (2012)

Regular Articles


Analysis of Simultaneous H and D Permeation through Lithium-Lead
Makoto OKADA, Yuki EDAO, Hiroaki OKITSU and Satoshi FUKADA
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
(Received 9 December 2011 / Accepted 18 April 2012 / Published 26 July 2012)

Abstract

Clarification of tritium transfer in blanket is an important issue for realizing fusion reactor. We perform an experiment of simultaneous H and D permeation through Li17Pb83 by means of an unsteady permeation method in order to clarify the interactions and isotope effects between H and D atoms. The experiment is conducted under the condition where the Sieverts' law holds. As a result, it is found that (i) H and D atoms permeate independently regardless of the H/D component ratio in the upstream gas and (ii) diffusion process is the rate-determining step in the overall permeation process. The diffusivity of H is around 1.4 times larger than that of D. The solubility of H is close to that of D. We estimate two vibration modes at an absorption site and a saddle point of H in Li17Pb83 based on the ratio of isotope effect. It is considered that the zero-point vibration energy of H at the absorption site in Li17Pb83 is around 0.173 eV and that at the saddle point is around 0.235 eV. The ratio of isotope effect is almost in proportion to the square root of mass ratio of D to H. The diffusivity of T can be estimated as 1/1.7 times of H.


Keywords

lithium-lead, liquid blanket, diffusivity, solubility, isotope effect, zero-point vibration energy

DOI: 10.1585/pfr.7.2405074


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This paper may be cited as follows:

Makoto OKADA, Yuki EDAO, Hiroaki OKITSU and Satoshi FUKADA, Plasma Fusion Res. 7, 2405074 (2012).