7–11 Jul 2014
Europe/Amsterdam timezone

Experimental Investigation of Cooling Capacity of 4K GM Cryocoolers in Magnetic Fields

8 Jul 2014, 14:15
1h 45m
Poster presentation (105min) Tue-Af-Posters Session 1.2

Speaker

Mr Takaaki Morie (Sumitomo Heavy Industries, Ltd.)

Description

4 K GM cryocoolers have been widely used for cooling superconducting magnets, such as, magnets in MRI systems. When an MRI system is operated, superconducting magnets generate a high magnetic field. Accordingly, 4K GM cryocoolers, which are installed in the MRI system, are inevitably exposed to the magnetic field. Especially, the heat capacity of the magnetic regenerator materials and the torque of the coldhead driving motors in the 4K GM cryocoolers will be affected by the magnetic field. In general, the cooling capacity of a 4K GM cryocooler is strongly dependent on the heat capacity of the magnetic regenerator materials, such as HoCu2, ErNi3 and Gd2O2S(GOS). In order to clarify the effect, we measured the cooling capacity of a Sumitomo Heavy Industry, Ltd. (SHI) 1W 4K GM cryocooler in magnetic fields up to 2.0 T. It is found that the impact of a magnetic field on the cooling capacity with a HoCu2/GOS hybrid regenerator is much smaller than that with a HoCu2 regenerator. The detail experimental results will be reported in this paper.

Primary author

Mr Takaaki Morie (Sumitomo Heavy Industries, Ltd.)

Co-author

Mr Taisuke Shiraishi (Sumitomo Heavy Industries, Ltd.)

Presentation materials