49th Annual Meeting of the Division of Plasma Physics
Volume 52, Number 11
Monday–Friday, November 12–16, 2007;
Orlando, Florida
Session KI2: Plasma Based Accelerators and Sources
3:00 PM–5:00 PM,
Tuesday, November 13, 2007
Rosen Centre Hotel
Room: Salon 3/4
Chair: Wim Leemans, Lawrence Berkeley National Laboratory
Abstract ID: BAPS.2007.DPP.KI2.1
Abstract: KI2.00001 : Laser Wakefield Structures and Electron Acceleration in Gas Jet and Capillary Discharge Plasmas*
3:00 PM–3:30 PM
Preview Abstract
Abstract
Author:
Anatoly Maksimchuk
(University of Michigan)
Laser-driven plasma wakefield accelerators have the potential to
become the
next generation of particle accelerators because of the very high
acceleration gradients. The beam quality from such accelerators
depends
critically on the details plasma wave spatial structures. In
experiments at
the University of Michigan it was possible in a single shot by
frequency
domain holography (FDH) to visualize individual plasma waves
produced by the
40 TW, 30 fs Hercules laser focused to the intensity of 10$^{19}$
W/cm$^{2}$
onto a supersonic He gas jet [1]. These holographic ``snapshots''
capture
the evolution of multiple wake periods, and resolve wavefront
curvature seen
previously only in simulations. High-energy quasi-monoenergetic
electron
beams for plasma density in the specific range 1.5$\times
$10$^{19}\le
$n$_{e}\le $3.5$\times $10$^{19}$ cm$^{-3 }$were generated [2]. The
experiments show that the energy, charge, divergence and pointing
stability
of the beam can be controlled by changing n$_{e}$, and that
higher electron
energies and more stable beams are produced for lower densities. An
optimized quasi-monoenergetic beam of over 300 MeV and 10 mrad
angular
divergence is demonstrated at a plasma density of n$_{e}$=1.5$\times
$10$^{19}$ cm$^{-3}$. The resulted relativistic electron beams
have been
used to perform gamma-neutron activation of $^{12}$C and
$^{63}$Cu and
photo-fission of $^{238}$U with a record high reaction yields of
$\sim
$5x10$^{5}$/Joule [3]. Experiments performed with ablative capillary
discharge plasma demonstrate stable guiding for laser power up to
10 TW with
the transmission of 50{\%} and guided intensity of $\sim $10$^{17}$
W/cm$^{2}$. Study of the staged electron acceleration have been
performed
which uses ablated plasma in front of the capillary to inject
electrons into
the wakefield structures.
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[1] N. H. Matlis et. al., Nature Physics \textbf{2,} 749 (2006).
\newline
[2] A. Maksimchuk et. al., Journal de Physique IV \textbf{133},
1123 (2006).
\newline
[3] S. A. Reed et. al., Appl. Phys. Lett. \textbf{89}, 231107
(2006).
*Supported by the NSF through the Physics Frontier Center FOCUS, grant PHY-0114336.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.DPP.KI2.1