title: Low temperature laser scanning microscopy of a superconducting radio-frequency cavity.
abstract: An apparatus was developed to obtain, for the first time, 2D maps of the surface resistance of the inner surface of an operating superconducting radio-frequency niobium cavity by a low-temperature laser scanning microscopy technique. This allows identifying non-uniformities of the surface resistance with a spatial resolution of about 2.4 mm and surface resistance resolution of ~1 μΩ at 3.3 GHz. A signal-to-noise ratio of about 10 dB was obtained with 240 mW laser power and 1 Hz modulation frequency. The various components of the apparatus, the experimental procedure and results are discussed in detail in this contribution.
authors.affiliation: Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, Virginia 23606, USA. gciovati@jlab.org
authors.forename: G
authors.initials: G
authors.lastname: Ciovati
authors.forename: Steven M
authors.initials: SM
authors.lastname: Anlage
authors.forename: C
authors.initials: C
authors.lastname: Baldwin
authors.forename: G
authors.initials: G
authors.lastname: Cheng
authors.forename: R
authors.initials: R
authors.lastname: Flood
authors.forename: K
authors.initials: K
authors.lastname: Jordan
authors.forename: P
authors.initials: P
authors.lastname: Kneisel
authors.forename: M
authors.initials: M
authors.lastname: Morrone
authors.forename: G
authors.initials: G
authors.lastname: Nemes
authors.forename: L
authors.initials: L
authors.lastname: Turlington
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Zhang