Abstract
Free electron lasers operating with two colors are promising devices for applications. The relevant modelization has provided a good understanding of the underlying physics. In this paper we present an analysis of the experimental results obtained at SPARC_LAB concerning seeded two-colors free electron laser (FEL) operation. The use of an ad hoc developed semi-analytical model based on the small-signal FEL integral equation reproduces most of the observed phenomenology. The paper discusses the reliability of the proposed method, the range of validity and its possible improvement.
Highlights
This paper is devoted to the analysis of some experimental results obtained at the SPARC test facility at SPARC_LAB, concerning the free electron laser (FEL) operating with two colors
The model includes an appropriate rehandling of the FEL small-signal highgain equation and it appears suitable to reproduce most of the two-color phenomenology observed at SPARC; the relevant limitations and possible improvements are discussed below
We have shown that the phenomenology associated with two-color dynamics is fairly rich and that it can be treated with a straightforward numerical tool, exploiting a properly modified FEL high-gain equation
Summary
This paper is devoted to the analysis of some experimental results obtained at the SPARC test facility at SPARC_LAB, concerning the free electron laser (FEL) operating with two colors. Several theoretical proposals have been developed to explore the physics underlying the double color FEL process [11,12,13,14,15] Albeit these models contain all the features for an indepth analysis of the relevant physics, we have developed a less general tool, of semi-analytical nature, suitable for the present purposes being manageable and containing mode competition and slippage. We have assumed negligible the effects due to finite energy spread and emittances, the e-beam portions determining the two frequencies are supposed identical and characterized by the same Pierce parameter ρ. In these introductory remarks we are interested in clarifying how the two “modes” grow, what is the relevant interplay and under which conditions they can be considered independent. The first step toward such a goal is the solution of Eq (1) by means of a hybrid procedure that foresees the combined
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
