The Axion Longitudinal Plasma Haloscope (ALPHA) experiment reached a milestone on February 24 with the successful installation of a Bluefors helium dilution fridge at the site of the experiment in Wright Lab.
ALPHA will extend the search for a hypothetical dark matter candidate—a very low-mass particle called the axion—to a higher mass range than has been searched for previously.
Michael Jewell, associate research scientist in physics and a member of Yale’s Wright Lab is the ALPHA project technical coordinator. Jewell explained, “In order for ALPHA to achieve its physics goal, we need to limit any potential noise source. For us, the biggest source of noise is thermal noise from the experiment. So we operate the whole experiment in the coldest commercially available systems, which are helium dilution fridges that are able to cool down to ~10 millikelvin (mK).”
Jewell noted that after the installation of the fridge, a base temperature just below 10 mK was demonstrated. Jewell said, “This will allow us to limit thermal noise and to operate our quantum amplifiers, which themselves need to be operated at sub Kelvin temperatures in order to achieve amplification at the quantum limit.”
According to Jewell, the effort to “assemble the system, integrate the system into the lab space and test the system’s performance” was a group effort, which included Jewell; Wright Lab postdocs Tyler Johnson and Max Silva-Feaver; graduate students Eunice Beato, Eleanor Graham, Claire Laffan, and Sukhman Singh; technical staff Jeff Ashenfelter, Tom Barker, Tom Hurteau, and Frank Lopez; and Pranjal Tiwari, a Cryo Engineer from Bluefors, the company that provided the fridge.
The ALPHA experiment includes researchers from UC Berkeley, Yale, MIT, Johns Hopkins, Wellesley, Arizona State University, Stockholm University, ITMO University, Cambridge, and Oak Ridge National Laboratory.
Reina Maruyama, professor of physics, is the deputy spokesperson of ALPHA and PI of the Yale ALPHA team, which also includes the groups of Yale Physics faculty Sean Barrett, professor of physics; Charles Brown, assistant professor of physics; Karsten Heeger, Eugene Higgins Professor and Chair of Physics and director of Wright Lab; and Steve Lamoreaux, Eugene Higgins Professor of Physics.
ALPHA is funded and supported by the Simons Foundation, John Templeton Foundation, Knut and Alice Wallenberg Foundation, Yale University, and Wright Lab.
Pictures of the installation can be found on the Wright Lab Flickr page.