[Triumf-seminars] TRIUMF Accelerator Seminar today at 10:30

[TRIUMF Seminars]

Date/Time: Fri 2012-03-02 at 10:30

Location:  TRIUMF Auditorium   

Speaker:   Gianluigi Ciovati (Jefferson Lab, USA)

Title:     Laser heating and laser scanning microscopy of an SRF cavity

Abstract: The performance in terms of the dependence of the quality factor from the accelerating field of superconducting radio-frequency (SRF) cavities is limited by the occurrence of anomalous losses, often referred to as “hotspots”.  Several mechanisms can cause such losses but their origin is still unclear. An apparatus was designed and built to use a low temperature laser scanning microscopy technique to obtain, for the first time, 2D maps of the surface resistance of the inner surface of an operating SRF niobium cavity. The setup was used to identify hotspots with ~1 mm spatial resolution and ~1  surface resistance resolution at 3.3 GHz. The same setup was used to investigate the role of pinned vortices on high-field rf losses by attempting to move the hotspots by applying a thermal gradient produced by the laser beam onto the cavity inner surface.

Stimulants available 15 minutes before the talk.

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