Higher-Order-Mode damping and microwave absorption at 2K

Conference · Sun Mar 01 04:00:00 EST 1992

OSTI ID:7280424

Campisi, I E; Finger, K E; Summers, L K; Johnson, A M

A special ceramic material for microwave absorption at low temperature has been developed at CEBAF to manufacture the 676 Higher-Order-Mode (HOM) loads for the machine. The accelerator includes 338 5-cell niobium cavities, resonating in the fundamental TM{sub 010}{pi} mode at 1497 MHs, in two antiparallel linacs (160 cavities each) and an injector (18 cavities). Higher-Order-Mode (HOM) power generation in the machine is expected to be in the tens of milliwatts per cavity at the nominal beam current of 200 {mu}A. This amount of power constitutes a small fraction of the power dissipated by the superconducting cavities at the operating gradient of 5 MV/m (typically less than 5 W per cavity) and the HOM power is more efficiently absorbed at the bat temperature of 2K than at room temperature. The HOM extraction is done via two S-band waveguides located orthogonally to each other at one end of the cavities and a load is placed at the end of each waveguide. This HOM damping scheme is characteristic of CEBAF alone: the low operating temperature and the vacuum in common with the superconducting cavities prevent the use of standard absorbers. Totally new materials and a novel absorber shape were developed for this application. 9 refs.

• Research Organization: Southeastern Universities Research Association, Inc., Newport News, VA (United States). Continuous Electron Beam Accelerator Facility
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 7280424
• Report Number(s): DOE/ER/40150-188; CEBAF-PR--92-010; CONF-920315--41; ON: DE92016960
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430303* -- Particle Accelerators-- Experimental Facilities & Equipment
ABSORPTION
ACCELERATORS
CAVITY RESONATORS
CEBAF ACCELERATOR
CERAMICS
DAMPING
ELECTRONIC EQUIPMENT
EQUIPMENT
LINEAR ACCELERATORS
OSCILLATION MODES
RESONATORS
RF SYSTEMS
SORPTION
SUPERCONDUCTING CAVITY RESONATORS
SUPERCONDUCTING DEVICES
WAVEGUIDES