• T. Tajima, A.S. Bhatty, A. Canabal, P. Chacon, G.V. Eremeev, R.J. Roybal, J.D. Sedillo
  LANL, Los Alamos, New Mexico

Funding: DTRA

A temperature mapping system with 4608 100-ohm Allen-Bradley resistors has been built and tested at LANL. With this temperature mapping system we were able to locate lossy regions in the 1.3 GHz 9-cell SRF cavity due to field emission and direct heating. The results of the temperature mapping have been correlated with the inside surface inspection of the cavity and will be shown together with Q-E curves. A brief description of the mapping system and improvements that have been made in the recent months will also be mentioned in the paper.

• T. Tajima, A. Canabal, G.V. Eremeev
  LANL, Los Alamos, New Mexico
• I.E. Campisi
  ORNL, Oak Ridge, Tennessee
• V.A. Dolgashev, S.G. Tantawi
  SLAC, Menlo Park, California
• X. Xi
  Penn State University, University Park, Pennsylvania

Funding: DTRA

We are currently testing the effect of coating Nb with a thin layer of another superconductor such as NbN and MgB2. Gurevich’s theory of multi-layered coating predicts an enhancement of the critical magnetic field, giving us hope to increase the achievable accelerating gradient to above 50 MV/m in elliptical cavities. CW test results of 3 GHz Nb single-cell cavities coated with ~100 nm NbN at LANL and 11.4 GHz <1 μs high-power pulsed test results of 2” Nb disk samples coated with ~100 nm MgB2 will be presented.