Micro Cooling of SQUID Sensor

B. Ottosson[1], Y. Jouahri[2], C. Rusu[1], and P. Enoksson[2]
[1]Imego AB, Gothenburg, Sweden
[2]Chalmers University of Technology, Gothenburg, Sweden

The objective of this work has been to realize a feasibility study of a cooling device for a SQUID sensor using liquid nitrogen flowing through micro channels. The design consists of an epoxy cylindrical vacuum vessel skewed by a silicon microchannel heat sink. The SQUID sensor is situated directly on top of the microchannel heat sink. The device is used at room temperature and should be able to cool down the SQUID top surface under 80K. The main work consisted in optimizing the heat sink and vessel design, using thermal, micro-fluidic and mechanical three-dimensional numerical simulations, to match the SQUID sensor working condition requirements. It has been shown, using COMSOL Multiphysics software that the 80K limit can be reached, using liquid nitrogen with an inlet temperature of 70K and flow velocity of 0.05 m/s, flowing in 100 μm by 1500 μm wide channels.