Submitted on February 16, 2001
Accepted on April 20, 2001
Exponential Gain and Saturation of a Self-Amplified Spontaneous Emission Free-Electron Laser
S. V. Milton 1*,
E. Gluskin 1,
N. D. Arnold 2,
C. Benson 1,
W. Berg 1,
S. G. Biedron 3,
M. Borland 1,
Y.-C. Chae 1,
R. J. Dejus 1,
P. K. Den Hartog 1,
B. Deriy 1,
M. Erdmann 1,
Y. I. Eidelman 1,
M. W. Hahne 1,
Z. Huang 1,
K.-J. Kim 1,
J. W. Lewellen 1,
Y. Li 1,
A. H. Lumpkin 1,
O. Makarov 1,
E. R. Moog 1,
A. Nassiri 1,
V. Sajaev 1,
R. Soliday 1,
B. J. Tieman 1,
E. M. Trakhtenberg 1,
G. Travish 1,
I. B. Vasserman 1,
N. A. Vinokurov 4,
G. Wiemerslage 1,
B. X. Yang 1
1 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
2 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
3 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA; MAX-Laboratory, University of Lund, 221 00 Lund, Sweden.
4 Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russian Federation.
* To whom correspondence should be addressed. E-mail: milton{at}aps.anl.gov.
Self-amplified spontaneous emission in a free-electron laser is a proposed technique for the generation of very high-brightness coherent x-rays. The process involves passing a high-energy, high-charge, short-pulse, low-energy-spread, and low-emittance electron beam through the periodic magnetic field of a long series of high-quality undulator magnets. The radiation produced grows exponentially in intensity until it reaches a saturation point. We report on the demonstration of self-amplified spontaneous emission gain, exponential growth, and saturation at wavelengths in the visible (530 nm) and ultraviolet (385 nm). Good agreement between theory and simulation indicates that scaling to much shorter wavelengths may be possible. These results confirm the physics behind the self-amplified spontaneous emission process and move us a step closer toward an operational x-ray free-electron laser.
