Rectangular Dielectric-loaded Structures for Achieving High Acceleration Gradients

Journal Article · Mon Nov 27 00:00:00 EST 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2409233· OSTI ID:20898775

Changbiao, Wang; Yakovlev, V P ^[1]; Marshall, T C ^[2]; LaPointe, M A ^[3]; Hirshfield, J L ^[1]

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1. Omega-P, Inc., New Haven, CT 06511 (United States)
2. Columbia University, Applied Physics Department, New York, NY 10027 (United States)
3. Yale University, Physics Department, New Haven, CT 06520 (United States)

Rectangular dielectric-loaded structures are described that may sustain higher acceleration gradients than conventional all-metal structures with similar apertures. One structure is a test cavity designed to ascertain the breakdown limits of dielectrics, while a second structure could be the basis for a two-beam accelerator. CVD diamond is an attractive dielectric for a high-gradient structure, since the published DC breakdown limit for CVD diamond is {approx} 2 GV/m, although the limit has never been determined for RF fields. Here we present a design of a diamond-lined test cavity to measure the breakdown limit. The designed cavity operates at 34 GHz, where with 10-MW input power it is expected to produce an {approx}800 MV/m field on the diamond surface - provided breakdown is avoided. The two channel rectangular dielectric-loaded waveguide could be a two-beam accelerator structure, in which a drive beam is in one channel and an accelerated beam is in the other. The RF power produced by drive bunches in the drive channel is continuously coupled to the acceleration channel. The ratio of fields in the channels (transformer ratio) for the operating mode can be designed by adjusting the dimensions of the structure. An example of the two-channel structure is described, in which a train of five 3-nC drive bunches excites wake fields in the accelerator channel of up to 1.3 GV/m with a transformer ratio of 10 for the design mode.

• OSTI ID: 20898775
• Journal Information: AIP Conference Proceedings, Vol. 877, Issue 1; Conference: 12. advanced accelerator concepts workshop, Lake Geneva, WI (United States), 10-15 Jul 2006; Other Information: DOI: 10.1063/1.2409233; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
36 MATERIALS SCIENCE
ACCELERATION
ACCELERATORS
APERTURES
BREAKDOWN
CHEMICAL VAPOR DEPOSITION
DIAMONDS
DIELECTRIC MATERIALS
GHZ RANGE 01-100
TRANSFORMERS
WAVEGUIDES