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Title: Gradient Limitations in Room Temperature and Superconducting Acceleration Structures

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.3080933· OSTI ID:21255247
 [1]
  1. Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of {approx}200 ns pulses for breakdown rate of {approx}10{sup -7}. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R and D program.

OSTI ID:
21255247
Journal Information:
AIP Conference Proceedings, Vol. 1086, Issue 1; Conference: 13. advanced accelerator concepts workshop, Santa Cruz, CA (United States), 27 Jul - 2 Aug 2008; Other Information: DOI: 10.1063/1.3080933; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English