Joe Frisch: Synchrotron radiation sources and free ... - Conferences

Short Wavelength Limits
• Emission wavelength scales as γ 2 ,
but gain tends to decrease with
wavelength.
• Above ~20 KeV, an additional
effect decreases FEL gain: The
energy spread from statistics in
spontaneous emission increases
the beam energy spread and
reduces the gain further.
• For LCLS beam parameters, 25 KeV
seems practical
• Design studies with low emittance
beams suggest energies up to
~100 KeV may be possible.
• High energy X-rays put tight
constraints on beam brightness
and undulator quality
FELs above 25 KeV are likely to be very large facilities,
need to understand the science case
Calculated gain length and power for 25KeV
FEL using LCLS like beam parameters
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