CERN Accelerating science

Article
Report number	SLAC-PUB-11207
Title	High Gradient Performance of NLC/GLC X-Band Accelerating Structures
Author(s)	Döbert, Steffen ; Adolphsen, Chris ; Boffo, Cristian ; Bowden, Gordon B ; Burke, David ; Carter, Harry ; Chan, Jose ; Dolgashev, Valery A ; Frisch, Josef ; Funahashi, Y ; Gonin, Ivan V ; Hayano, Hitoshi ; Higashi, Norio ; Higashi, Yasuo ; Higo, Toshiyasu ; Jobe, R Keith ; Jones, Roger M ; Kawamata, H ; Khabiboulline, Timergali N ; Kirby, Robert ; Kume, T ; Lewandowski, James R ; Li, Zenghai ; McCormick, Douglas ; Miller, Roger H ; Mishra, Shekhar ; Morozumi, Yuichi ; Nantista, Christopher D ; Nelson, Janice ; Pearson, Chris ; Romanov, Gennady ; Ross, Marc ; Schultz, David ; Smith, Tonee ; Solyak, Nikolay ; Tacku Arkan, Tug ; Takata, Koji ; Takatomi, Toshikazu ; Tantawi, Sami G ; Toge, Nobu ; Ueno, K ; Wang, Juwen W ; Watanabe, Y
Affiliation	(Fermilab, Batavia, Illinois) ; (KEK, Ibaraki) ; (KEK, Tsukuba, Ibaraki) ; (SLAC)
Publication	2005
Imprint	2005
Number of pages	3
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.372
Subject category	Accelerators and Storage Rings
Abstract	During the past five years, there has been an concerted effort at FNAL, KEK and SLAC to develop accelerator structures that meet the high gradient performance requirements for the Next Linear Collider (NLC) and Global Linear Collider (GLC) initiatives. The structure that resulted is a 60-cm-long, traveling-wave design with low group velocity (< 4% c) and a 150 degree phase advance per cell. It has an average iris size that produces an acceptable short-range wakefield in the linacs, and dipole mode damping and detuning that adequately suppresses the long-range wakefield. More than eight such structures have operated over 1000 hours at a 60 Hz pulse rate at the design gradient (65 MV/m) and pulse length (400 ns), and have reached breakdown rate levels below the limit for the linear collider. Moreover, the structures are robust in that the breakdown rates continue to decrease over time, and if the structures are briefly exposed to air, the rates recover to their low values within a few days. This paper presents a final summary of the results from this program, which effectively ended last August with the selection of 'cold' technology for a next generation linear collider.