1201.5386 (G. Ciovati et al.)

Low temperature laser scanning microscopy of a superconducting
radio-frequency cavity    [PDF]

G. Ciovati, Steven M. Anlage, C. Baldwin, G. Cheng, R. Flood, K. Jordan, P. Kneisel, M. Morrone, G. Nemes, L. Turlington, H. Wang, K. Wilson, S. Zhang

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 one order of magnitude better than with
earlier methods and surface resistance resolution of ~ 1 micro-Ohm 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.

View original: http://arxiv.org/abs/1201.5386