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M. A. Anil

Publications and source records attributed to M. A. Anil.

3 recordsLinked to original sources

Design and Operational Experience of a Microwave Cavity Axion Detector for the 20-100 micro-eV Range

We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the $5 - 25$ GHz range ($\sim20-100\: μ$eV). The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

physics.ins-det

First results from a microwave cavity axion search at 24 micro-eV

We report on the first results from a new microwave cavity search for dark matter axions with masses above $20~μ\text{eV}$. We exclude axion models with two-photon coupling $g_{aγγ} \gtrsim 2\times10^{-14}~\text{GeV}^{-1}$ over the range $23.55~μ\text{eV} < m_a < 24.0~μ\text{eV}$. These results represent two important achievements. First, we have reached cosmologically relevant sensitivity an order of magnitude higher in mass than any existing limits. Second, by incorporating a dilution refrigerator and Josephson parametric amplifier, we have demonstrated total noise approaching the standard quantum limit for the first time in an axion search.

astro-ph.CO

Future Directions in the Microwave Cavity Search for Dark Matter Axions

The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonant conversion to photons in a microwave cavity permeated by a magnetic field. The current generation of the microwave cavity experiment has demonstrated sensitivity to plausible axion models, and upgrades in progress should achieve the sensitivity required for a definitive search, at least for low mass axions. However, a comprehensive strategy for scanning the entire mass range, from 1-1000 $μ$eV, will require significant technological advances to maintain the needed sensitivity at higher frequencies. Such advances could include sub-quantum-limited amplifiers based on squeezed vacuum states, bolometers, and/or superconducting microwave cavities. The Axion Dark Matter eXperiment at High Frequencies (ADMX-HF) represents both a pathfinder for first data in the 20-100 $μ$eV range ($\sim$5-25 GHz), and an innovation test-bed for these concepts.

physics.ins-det