Estimating the maximum heating of NbN film with a current pulse at a low temperature: calculation by heat conduction equation
M.A. Vasyutin, E.V. Danilova, N.D. Kuzmichev
Ogarev Mordovia State University, Saransk, Russia
Keywords: heat transfer, inhomogeneous heat equation, boundary value problem, beryllium copper, NbN film
Abstract
The process of heat transfer in NbN film while applying a pulse of current is considered using the 2D inhomogeneous heat equation. The boundary value problem is solved for a longitudinal cross-section in the film; the heat transfer problem is solved for a system “contacts-film-substrate-thermostat”. The temperature evolution for the film cross-section since the pulse start till the temperature relaxation is visualized. The maximum film heating is evaluated. It was shown that the contact material (beryllium cooper BeCu) ensures the effective heat drainage from a superconductive film existing in the resistance mode while passing a high density current through the film. The developed simulation method and the material for the contacts can be used for other types of metallic or semiconductor films.
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