“Searching for QCD Axion Dark Matter with the Princeton Axion Search and DMRadio”
QCD axions, originally motivated as a solution to the Strong CP problem in quantum chromodynamics, are also a strong candidate for dark matter, the mysterious “missing mass” in our universe. In this talk, I overview the scientific motivation for axions and describe the Princeton Axion Search (PXS), a search for QCD axion dark matter in the 0.8-2.1 ueV mass range (corresponding to 200-500 MHz frequency range). This is a critical transitional mass range between the DMRadio program, which operates below any cavity modes and utilizes lumped-element techniques, and the cavity regime probed by higher frequency searches. I describe development efforts into all aspects of the experimental apparatus, including the cryogenics, solenoidal magnet, near-quantum-limited readout amplifiers, and resonators needed for a definitive search in this mass range. PXS leverages a strong partnership with the Princeton Plasma Physics Laboratory (PPPL) to design and construct a large bore, conduction-cooled solenoid. The experiment also benefits from a partnership with Caltech/JPL to implement parametric amplifiers in this frequency range. PXS is also developing superconducting resonators and readouts operating beyond the Standard Quantum Limit of amplification in collaboration with the DMRadio program, which aims to probe QCD axions at the lower sub-ueV mass range. I discuss some of these collaborative efforts.
Host: Max Silva-Feaver