Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Dynamic acoustic optimization of pulse tube refrigerators for rapid cooldown



Ryan Snodgrass, Vincent Kotsubo, Scott Backhaus, Joel Ullom


Pulse tube refrigerators are a critical enabling technology for many disciplines that require low temperatures. These refrigerators dominate the total power consumption of most modern cryostats, including those that reach millikelvin temperatures using additional cooling stages. In state-of-the-art commercial pulse tube refrigerators, the acoustic coupling between the driving compressor and the refrigerator is fixed and optimized for operation at base temperature. We show that this optimization is incorrect during the cooldown process, which results in wasted power consumption by the compressor and slow cooldown speed. After developing analytic expressions that demonstrate the need for acoustic tuning as a function of temperature, we dynamically optimize the acoustics of a commercial pulse tube refrigerator and show that the cooldown speed can be increased to 1.7 to 3.5 times the original value. Acoustic power measurements show that loss mechanism(s)—and not the capacity of the compressor—limit the maximum cooling available at high temperatures, suggesting that even faster cooldown speeds can be achieved in the future. This work has implications for the accessibility of cryogenic temperatures and the cadence of research in many disciplines such as quantum computing.
Nature Communications


Pulse tube refrigerator, compressor, thermoacoustics, cooldown speed, rapid cooldown


Snodgrass, R. , Kotsubo, V. , Backhaus, S. and Ullom, J. (2024), Dynamic acoustic optimization of pulse tube refrigerators for rapid cooldown, Nature Communications, [online],, (Accessed May 26, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created April 23, 2024