Abstract: An acoustic cooling device is provided. A coldhead and an acoustic power source of the acoustic cooling device are separated by way of a long tube connecting them to enable the cold tip to be installed in a remote location where a traditional unitary system would not fit, would generate too much vibration, or would be otherwise undesirable. The dimensions of the tube and the relevant parameters of the acoustic power source are selected to keep the system resonant at the desired drive frequency (e.g., 60 Hz) and to minimize the impact of the long tube on the system efficiency and capacity.

Abstract: A free piston device which is particularly applicable for use with a linear motor for providing acoustic energy to a cryocooler for generating refrigeration at cryogenic temperatures which comprises a time varying clearance seal to counteract piston drift.