2009 APS April Meeting
Volume 54, Number 4
Saturday–Tuesday, May 2–5, 2009;
Denver, Colorado
Session R6: Imaging Advanced Accelerators
1:30 PM–3:18 PM,
Monday, May 4, 2009
Room: Governor's Square 16
Sponsoring
Units:
DPP DPB
Chair: Thomas Antonsen, University of Maryland
Abstract ID: BAPS.2009.APR.R6.3
Abstract: R6.00003 : Optical Diagnostics for Plasma-based Particle Accelerators*
2:42 PM–3:18 PM
Preview Abstract
Abstract
Author:
Patric Muggli
(University of Southern California)
One of the challenges for plasma-based particle accelerators is
to measure
the spatio-temporal characteristics of the accelerated particle
bunch.
``Optical'' diagnostics are particularly interesting and useful
because of
the large number of techniques that exits to determine the
properties of
photon pulses. The accelerated bunch can produce photons pulses
that carry
information about its characteristics for example through
synchrotron
radiation in a magnet, Cherenkov radiation in a gas, and transition
radiation (TR) at the boundary between two media with different
dielectric
constants. Depending on the wavelength of the emission when
compared to the
particle bunch length, the radiation can be incoherent or coherent.
Incoherent TR in the optical range (or OTR) is useful to measure the
transverse spatial characteristics of the beam, such as charge
distribution
and size. Coherent TR (or CTR) carries information about the
bunch length
that can in principle be retrieved by standard auto-correlation or
interferometric techniques, as well as by spectral measurements. A
measurement of the total CTR energy emitted by bunches with
constant charge
can also be used as a shot-to-shot measurement for the relative
bunch length
as the CTR energy is proportional to the square of the bunch
population and
inversely proportional to its length (for a fixed distribution).
Spectral
interferometry can also yield the spacing between bunches in the
case where
multiple bunches are trapped in subsequent buckets of the plasma
wave.
Cherenkov radiation can be used as an energy threshold diagnostic
for low
energy particles. Cherenkov, synchrotron and transition radiation
can be
used in a dispersive section of the beam line to measure the
bunch energy
spectrum. The application of these diagnostics to plasma-based
particle
accelerators, with emphasis on the beam-driven, plasma wakefield
accelerator
(PWFA) at the SLAC National Accelerator Laboratory will be discussed.
*This work is supported by the US Department of Energy.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.APR.R6.3