High Efficiency Energy Extraction from a Relativistic Electron Beam in a Strongly Tapered Undulator.
We present results of an experiment where, using a 200 GW CO_{2} laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54-cm-long strongly tapered helical magnetic undulator, extracting over 30% of the initial electron beam energy to coherent radiation. These results, supported by simulations of the radiation field evolution, demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.
Particle Beam Physics Laboratory, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
N
N
Sudar
Particle Beam Physics Laboratory, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
P
P
Musumeci
Particle Beam Physics Laboratory, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
J
J
Duris
Particle Beam Physics Laboratory, Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
I
I
Gadjev
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
M
M
Polyanskiy
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
I
I
Pogorelsky
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
M
M
Fedurin
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
C
C
Swinson
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
K
K
Kusche
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
M
M
Babzien
Faculty of Engineering, Department of Physical Electronics, Tel-Aviv University, Tel-Aviv 69978, Israel.
A
A
Gover