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Title: Photonic Crystal Laser-Driven Accelerator Structures

Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550more » nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.« less
Authors:
Publication Date:
OSTI Identifier:
915385
Report Number(s):
SLAC-R-877
arXiv:0708.3206; TRN: US0804974
DOE Contract Number:
AC02-76SF00515
Resource Type:
Thesis/Dissertation
Research Org:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 43 PARTICLE ACCELERATORS; ACCELERATION; ACCELERATORS; DESIGN; DIELECTRIC MATERIALS; EFFICIENCY; FABRICATION; MANUFACTURING; PARTICLE BEAMS; PERFORMANCE; PHASE VELOCITY; SILICON; WAVEGUIDES; WAVELENGTHS General Physics,ACCPHY, OPTICS