Learn about the physics of the Free Electron Laser

1. Free Electron laser

2. How a conventional laser works

3. How a FEL works
• To create a FEL, a beam of electrons are accelerated to high/ultra
relativistic speeds.
• The beam passes through a undulator/wiggler which is a periodic
arrangement of magnets with alternating poles across the beam path,
which creates a side to side magnetic field.
• Due to the Lorentz Force, the electrons in the beam wiggle
transversely, traveling along a sinusoidal path about the axis of the
undulator.
• The transverse acceleration of the electrons across this path results in
the release of synchrotron

5. How a Free Electron laser works

6. Undulator

7. The wavelength of the radiation
emitted can be easily tuned by
adjusting the energy of the electron
beam or the magnetic-field strength
of the undulators.

8. • The free-electron
laser was invented
by John Madey in
1971 at Stanford
University

9. Uses of FEL
• The radiation is highly tunable(just need to vary speed of electrons and or
magnetic strength)
• Tuning ability of FELs makes them highly desirable in many disciplines, including
chemistry, structure determination of molecules in biology, medical diagnosis
• synchrotron light sources have been the workhorses of protein crystallography
and cell biology
• Surgery: soft tissues including skin, cornea, and brain tissue could be cut,
or ablated, using infrared FEL wavelengths around 6.45 micrometres with
minimal collateral damage to adjacent tissue
• On June 9, 2009 the office of naval research announced it had
awarded raytheon a contract to develop a 100 kW experimental FEL.
• On March 18, 2010 Boeing Directed Energy Systems announced the completion
of an initial design for U.S. Naval use. A prototype FEL system was demonstrated,
with a full-power prototype scheduled by 2018.

10. Linac Coherent Light Source
• LCLS is a free electron facility located at SLAC.
• can deliver extremely intense x-ray radiation for
research in a number of areas
• The laser produces hard X-rays, 109 times the
relative brightness of traditional synchrotron
sources
• most powerful x-ray source in the world.
• x-rays can be used to take "snapshots" of objects at
the atomic level before obliterating samples.
• laser's wavelength, ranging from 0.13 to 6.2 nm
(200 to 9500 eV) x-ray, is on the order of the width
of an atom, providing extremely detailed
information that was previously unattainable
• https://www.youtube.com/watch?v=pgaG7f96SKM