Research output: Contribution to journal › Article › peer-review
Slowing Down the Diffusion of Helium by a Counter-Flow of Rarefied Hydrogen. / Kusenov, S.R.; Busnyuk, A.O.; Gorbachev, Yu.E. et al.
In: Vacuum, Vol. 245, 114948, 02.2026.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Slowing Down the Diffusion of Helium by a Counter-Flow of Rarefied Hydrogen
AU - Kusenov, S.R.
AU - Busnyuk, A.O.
AU - Gorbachev, Yu.E.
AU - Bykov, N.Y.
AU - Peredistov, E.Yu.
AU - Zaitsev, D.A.
AU - Livshits, A.I.
N1 - This study was conducted within the framework of the scientific program of the National Center for Physics and Mathematics, section # 8.
PY - 2026/2
Y1 - 2026/2
N2 - The study is primarily motivated by the need to separate He from and recirculate the Deuterium/Tritium (D/T) mixture in fusion devices. The success of the solution depends critically on whether the back diffusion of helium can be prevented by blocking it with a counter flow of D/T. The conditions of such blocking are found in a direct experiment, in which the diffusion of He against the hydrogen flow is investigated when Knudsen number, Kn, varies from 0.001 to 1. It was observed that the partial pressure of He decreases exponentially in the upstream direction from the admittance point with a characteristic braking length, L∗, which is inversely proportional to the He flow rate and does not depend on Kn not only in the case of continuum flow regime but also in the transitional regime up to Kn≈1. It was also found that L∗ is independent of the He to H2 flow rate ratio over the whole range investigated from 0.05 to 0.43. For the continuum regime and the case of a small admixture of one of the components, good agreement with the theoretical estimates within the continuum flow model is observed. Other experimentally studied flow regimes require more thorough theoretical analysis.
AB - The study is primarily motivated by the need to separate He from and recirculate the Deuterium/Tritium (D/T) mixture in fusion devices. The success of the solution depends critically on whether the back diffusion of helium can be prevented by blocking it with a counter flow of D/T. The conditions of such blocking are found in a direct experiment, in which the diffusion of He against the hydrogen flow is investigated when Knudsen number, Kn, varies from 0.001 to 1. It was observed that the partial pressure of He decreases exponentially in the upstream direction from the admittance point with a characteristic braking length, L∗, which is inversely proportional to the He flow rate and does not depend on Kn not only in the case of continuum flow regime but also in the transitional regime up to Kn≈1. It was also found that L∗ is independent of the He to H2 flow rate ratio over the whole range investigated from 0.05 to 0.43. For the continuum regime and the case of a small admixture of one of the components, good agreement with the theoretical estimates within the continuum flow model is observed. Other experimentally studied flow regimes require more thorough theoretical analysis.
UR - https://www.scopus.com/pages/publications/105024212563
UR - https://www.mendeley.com/catalogue/52908914-473b-3bae-93e0-a4a0e14bc912/
U2 - 10.1016/j.vacuum.2025.114948
DO - 10.1016/j.vacuum.2025.114948
M3 - Article
VL - 245
JO - Vacuum
JF - Vacuum
SN - 0042-207X
M1 - 114948
ER -
ID: 72574164