About SRF 
  Brief introduction 

 SRF cavities are made of different materials, in all shapes and sizes. 
Superconducting Radio Frequency (SRF) science and technology deals with the application of  superconducting materials to radio frequency (RF) devices. It is well known that many materials,  known as superconductors, lose all DC electrical resistance when the temperature drops below  the critical temperature 
Tc . Unlike DC resistance, the RF surface resistivity is zero  only at 
T = 0 K (absolute zero). At temperatures above absolute zero, but below the critical  temperature, the surface resistivity is greatly reduced, yet non-zero. The ultra-low resistivity of  the superconductor yields RF resonators with extremely high quality factors 
Q , typically higher  than 10
10at frequencies of the order of 1 GHz and temperatures below 2 K. Such a very  high 
Q resonator and its narrow bandwidth can then be exploited for a variety of applications. RF superconductivity has become an important technology for contemporary particle accelerators, by far  its largest application.
  Textbooks and Brochures 
Hasan Padamsee RF Superconductivity 2010
Hasan Padamsee RF Superconductivity Companion 2010
 Hasan Padamsee RF Superconductivity: Volume II: Science, Technology and Applications. 978-3527405725
 Hasan Padamsee, Jens Knobloch, Tom Hays RF Superconductivity for Accelerators 978-3527408429
RF Superconductivity - 2004 brochure  (PDF, 10.6 MB), prepared by 
Hasan Padamsee , is aimed to 
summarize the status of the science, technology and applications of superconducting RF (SRF), and to discuss  exciting prospects for the future. 
  Websites 
Superconducting RF Cavities: A Primer   by 
J. Graber from 
SRF at Cornell website.
Superconducting Radio Frequency  from 
Wikipedia .
  Courses and Tutorials 
United States Particle Accelerator School (USPAS) and  
CERN Accelerator School (CAS) offer cources on RF superconductivity.  Some course materials are available online:
  
Starting in 2003, 
International Workshops (now Conferences) on RF Superconductivity offer tutorials,  which may be found in the online workshop proceedings:
  
  Links