Design chart of high temperature superconducting gas cooled current leads

General design equations derived from one dimensional energy balance equations are solved to evaluate generalized characteristics of gas cooled current leads which are made of high temperature superconducting (HTSC) material. Design parameters of the conductor and the cooling channel are combined into a single general cooling parameter with the consideration of laminar flow. Generalized characteristics of HTSC current leads, namely the heat flow from the cold end of the leads, the geometrical dimension of the conductor and the pressure drop of the cooling gas are represented in a design chart with the general cooling parameter. Thermal runaway of the conductor is analyzed for various geometrical dimensions in the case of stoppage of the cooling gas with the consideration of the quench propagation. The temperature rise time works as a criterion for determining the geometrical dimension according to the criterion, the heat flow from the cold end is estimated to be less than 0.1 mW/A.<>