ADMX

The experimental insert within the magnet showing (top to bottom) the thermal shielding, liquid helium reservoir and microwave cavity.

The ADMX cryostat/magnet ready to be installed into the experiment hall at the University of Washington.

The Axion Dark Matter eXperiment (ADMX) detects the very weak conversion of dark matter axions into microwave photons. Axion conversion into photons is stimulated by an apparatus consisting of an 8 tesla magnet and a cryogenically cooled high-Q tunable microwave cavity (shown at the upper right). The presence of nearby axions in the Milky Way halo would deposit a very tiny amount of power (less than a yoctowatt) when the cavity's resonant frequency is tuned to the axion mass.

An extraordinarily sensitive microwave receiver allows the very weak axion signal to be extracted from the noise. The experiment receiver features quantum-limited noise delivered by an exotic Superconducting QUantum Interference Device (SQUID) amplifier and lower temperatures from a ³He refrigerator.

ADMX is the first experiment sensitive to realistic dark-matter axion masses and couplings and the improved detector allows an even more sensitive search.