Title :
Use of Ferrite-50 to strongly damp higher order modes
Author :
Moffat, D. ; Barnes, P. ; Kirchgessner, J. ; Padamsee, H. ; Rubin, D. ; Sears, J. ; Shu, Q.
Author_Institution :
Lab. for Nucl. Studies, Cornell Univ., Ithaca, NY, USA
Abstract :
A higher order mode damping concept has been proposed for use with the superconducting RF cavities for the Cornell B-Factory, CESR-B. All higher-order modes are brought out of the cavity via the beam tubes which have a large diameter and special shape. Because of their propagation, these modes can be damped by a 15-cm-long beam tube section of Ferrite-50 such that the Qs of all the modes are below 200, with most being below 100. The microwave losses of Ferrite-50 have been found to be >or=10/sup 4/ times higher than copper at approximately 1 GHz, and to decrease by a factor of 10 at 10 GHz. The tolerance of Ferrite-50 to high power has been tested up to 10 W/cm/sup 2/ (RMS).<>
Keywords :
beam handling techniques; electron accelerators; ferrites; storage rings; superconducting devices; CESR-B; Cornell B-Factory; Ferrite-50; beam tubes; damping concept; high power; higher order modes; microwave losses; propagation; superconducting RF cavities; tolerance; Conducting materials; Conductivity; Copper; Damping; Erbium; Ferrites; Frequency measurement; Impedance; Superconducting microwave devices; Testing;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.164397
