Title :
Accelerating cavity development for the Cornell B-factory, CESR-B
Author :
Padamsee, H. ; Barnes, P. ; Chen, C. ; Hartung, W. ; Hiller, M. ; Kirchgessner, J. ; Moffat, D. ; Ringrose, R. ; Rubin, D. ; Samed, Y. ; Saraniti, D. ; Sears, J. ; Shu, Q.S. ; Tigner, M.
Author_Institution :
Lab. of Nucl. Studies, Cornell Univ., Ithaca, NY, USA
Abstract :
To achieve luminosities of 30-100 times CESR, 1-2 A of current must be stored. A CESR B-factory parameter list calls for 50 MV for two rings, to be supplied by 16 cells operating at 10 MV/m gradient. With a new cell shape, the impedances of the dangerous higher order modes (HOM) are drastically reduced. All HOMs propagate out of the cavity via the beam pipe, which is specially shaped. This allows HOM power couplers to be placed completely outside the cryostat. A ferrite absorber on the beam pipe lowers all Qs to approximately 100, which is sufficient to avoid multibunch instabilities without feedback systems. A waveguide input coupler on the beam-pipe provides Qext as low as 5*10/sup 4/, with a C- slot shaped iris that has a negligible effect on the cavity loss parameter.<>
Keywords :
beam handling equipment; cavity resonators; electron accelerators; storage rings; CESR-B; accelerating cavity; cavity loss parameter; ferrite absorber; higher order modes; impedances; multibunch instabilities; power couplers; waveguide input coupler; Acceleration; Copper; Costs; Couplers; Impedance; Laboratories; Plugs; Radio frequency; Shape; Storage rings;
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.1991.164441
