title: Demonstration of a 17-GHz, high-gradient accelerator with a photonic-band-gap structure.
abstract: We report the testing of a high gradient electron accelerator with a photonic-band-gap (PBG) structure. The photonic-band-gap structure confines a fundamental TM(01)-like accelerating mode, but does not support higher-order modes (HOM). The absence of HOM is a major advantage of the PBG accelerator, since it suppresses dangerous beam instabilities caused by wakefields. The PBG structure was designed as a triangular lattice of metal rods with a missing central rod forming a defect confining the TM(01)-like mode and allowing the electron beam to propagate along the axis. The design frequency of the six-cell structure was 17.14 GHz. The PBG structure was excited by 2 MW, 100 ns pulses. A 16.5 MeV electron beam was transmitted through the PBG accelerator. The observed electron beam energy gain of 1.4 MeV corresponds to an accelerating gradient of 35 MV/m, in excellent agreement with theory.
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, 02139, USA. smirnova@mit.edu
authors.forename: Evgenya I
authors.initials: EI
authors.lastname: Smirnova
authors.forename: Amit S
authors.initials: AS
authors.lastname: Kesar
authors.forename: Ivan
authors.initials: I
authors.lastname: Mastovsky
authors.forename: Michael A
authors.initials: MA
authors.lastname: Shapiro
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Temkin