High-power free-electron laser amplifier using a scalloped electron beam and a two-stage wiggler
Abstract
High-power free-electron laser (FEL) amplifiers present many practical design and construction
problems. One such problem is possible damage to any optical beam control elements beyond the
wiggler. The ability to increase the optical beamâ s divergence angle after the wiggler, thereby reducing the
intensity on the first optical element, is important to minimize such damage. One proposal to accomplish
this optical beam spreading is to pinch the electron beam thereby focusing the radiation as well. In this
paper, we analyze an approach that relies on the natural betatron motion to pinch the electron beam near
the end of the wiggler. We also consider a step-tapered, two-stage wiggler to enhance the efficiency. The
combination of a pinched electron beam and step-taper wiggler leads to additional optical guiding of the
optical beam. This novel configuration is studied in simulation using the MEDUSA code. For a representative
set of beam and wiggler parameters, we discuss (i) the effect of the scalloped beam on the interaction
in the FEL and on the focusing and propagation of the radiation, and (ii) the efficiency enhancement in the
two-stage wiggler.
Description
The article of record as published may be found at http://dx.doi.org/10.1103/PhysRevSTAB.9.050703
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
A Scalloped Electron Beam Free-Electron Laser
Nguyen, D.C.; Freund, H.P.; Colson, W.B. (2006);Typical high-gain FEL amplifiers employ an electron beam that is â matchedâ to the wiggler so that the envelope remains constant throughout the wiggler. This paper describes a novel approach in which the electron envelope ... -
Magnetic field measurements of the CEBAF (NIST) wiggler using the pulsed wire method.
Wallace, Stephen M. (Monterey, California. Naval Postgraduate School, 1992-09);The Free Electron Laser (FEL) has proven to be a versatile photon source for many applications in science, industry and defense. It is capable of providing wide tunability and high efficiency, but has yet to yield the ... -
A transition radiation experiment to measure the electron beam modulation induced by the free electron laser: a design study
Joynson, Jack E. (1987-12);The modulated beam of the free electron laser when passed through a thin target should produce strong transition radiation. The measurement of the transition radiation is a direct measurement of the electron beam modulation ...