High Frequency Planar Accelerating Structures for Future Linear Colliders

Technical Report · Wed Jan 26 04:00:00 EST 2005

DOI:https://doi.org/10.2172/839665· OSTI ID:839665

Yu, D ^[1]

---

1. SLAC

Modern microfabrication techniques based on deep etch x-ray lithography (LIGA) can be used to produce large-aspect-ratio, metallic or dielectric, planar structures suitable for high-frequency RF acceleration of charged particle beams. Specifically, these techniques offer significant advantages over conventional manufacturing methods for future linear colliders (beyond NLC, the Next Linear Collider) because of several unique systems requirements. First, to have the required ac ''wall plug'' power within reasonable limits, such future linear colliders ({ge} 5TeV) must operate at high frequency ({ge} 30GHz). This implies the need of a large number of intricate accelerating structures with ever smaller dimensions and extremely tight manufacturing tolerances, imposing new challenges in mass-production, precision fabrication techniques. Microfabrication is particularly suitable for meeting this need. Secondly, luminosity requirements suggest the use of multi-bunch acceleration of electrons and positrons in the linear collider. In order for these schemes to accelerate low-emittance beams over a long distance, it is important that the wakefield effects be reduced to a minimum in the accelerating structure. Asymmetric planar structures have more geometric degrees of freedom than cylindrically symmetric structures. In addition to detuning, these can be utilized to further reduce the wakefields. Thirdly, in order to clearly discriminate physics events in the final interaction point at which electrons and positrons collide, it is required that secondary particle production from beamstrahlung be minimized. Flat electron and positron beams with a large aspect ratio will be beneficial in reducing beamstrahlung in the final focus region, but cause the beam to be more sensitive to wakefields in the vertical dimension. In principle, a flat beam can be accelerated in a planar structure with reduced wakefield in the vertical direction for the entire length of the accelerator.

• Research Organization: Stanford Linear Accelerator Center (SLAC), Menlo Park, CA
• Sponsoring Organization: SC
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 839665
• Report Number(s): SLAC-PUB-11000
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATION
ACCURACY
ASPECT RATIO
CHARGED PARTICLES
DEGREES OF FREEDOM
DIMENSIONS
ELECTRONS
FABRICATION
LINEAR COLLIDERS
LUMINOSITY
MANUFACTURING
PARTICLE PRODUCTION
PHYSICS
POSITRON BEAMS
POSITRONS