title: SQUID-based microwave cavity search for dark-matter axions.
abstract: Axions in the microeV mass range are a plausible cold dark-matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. We report the first result from such an axion search using a superconducting first-stage amplifier (SQUID) replacing a conventional GaAs field-effect transistor amplifier. This experiment excludes KSVZ dark-matter axions with masses between 3.3 microeV and 3.53 microeV and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Asztalos
authors.forename: G
authors.initials: G
authors.lastname: Carosi
authors.forename: C
authors.initials: C
authors.lastname: Hagmann
authors.forename: D
authors.initials: D
authors.lastname: Kinion
authors.forename: K
authors.initials: K
authors.lastname: van Bibber
authors.forename: M
authors.initials: M
authors.lastname: Hotz
authors.forename: L J
authors.initials: LJ
authors.lastname: Rosenberg
authors.forename: G
authors.initials: G
authors.lastname: Rybka
authors.forename: J
authors.initials: J
authors.lastname: Hoskins
authors.forename: J
authors.initials: J
authors.lastname: Hwang
authors.forename: P
authors.initials: P
authors.lastname: Sikivie
authors.forename: D B
authors.initials: DB
authors.lastname: Tanner
authors.forename: R
authors.initials: R
authors.lastname: Bradley
authors.forename: J
authors.initials: J
authors.lastname: Clarke