Designing a grating based free electron laser

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 483; no. 1; pp. 478 - 481
• Main Authors: Andrews, H.L., Walsh, J.E., Brownell, J.H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2002
• Subjects: Diffraction; Electrons; Free electron laser; Grating; Smith–Purcell; 41.60.C; Diffraction; Grating; Free electron laser; Smith–Purcell; Electrons
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(02)00365-0

A compact far-infrared free electron laser (FEL) driven by a moderate energy beam would have many applications in academic and industrial research. Our goal is to find the optimal operating parameters producing the highest gain for a grating FEL with either a SASE or oscillator configuration. The basic structure consists of a grating bounded above by a roof extending over a portion of its length. The dispersion relation for such a system can be found by expanding the electromagnetic fields in a series of resonant modes. When the fields and the beam have near-synchronous velocities, the fields grow at a rate determined by the imaginary component of
ω (
k for spatial growth) and group velocity. Relations between gain and beam energy, roof height, tooth depth and angle of curve intersection have been investigated.