The ADMX Dark-Matter Axion Search and Beyond

Uncovering the nature of dark matter is, to me, one of the most pressing issues in all of science. The axion, a hypothetical elementary particle, has long been recognized as an attractive dark-matter candidate. But early on, it was presumed its direct detection in the laboratory would be impossible due to the dark-matter axion's extraordinarily feeble couplings to matter and radiation. In 1983, Prof. Pierre Sikivie at the University of Florida conceptualized an apparatus consisting of a high-Q microwave cavity threaded by a large static magnetic field, with the minute cavity electromagnetic field amplified by an ultra-low-noise microwave amplifier. This apparatus had the potential to detect the rare conversions of nearby dark-matter axions into microwave photons within the cavity. Realizing this concept took decades of development. And finally, in the 2000's, the Axion Dark Matter eXperiment (ADMX) at last achieved sensitivity to highly-plausible benchmark axions with dark-matter axion masses. This result was a milestone in axion dark-matter research and marked the transition of dark-matter axion detection from R&D to production experiments. This talk is an overview of the development of ADMX and a brief look into its future direction.