SHOCK WAVE PARTICLE ACCELERATION in LASER-PLASMA INTERACTION

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SHOCK WAVE PARTICLE ACCELERATION in LASER-PLASMA
INTERACTION

• G.I.Dudnikova, T.V.Leseykina
• ICT SBRAS

SCT-2012, Novosibirsk, June 8, 2012
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Introduction Motivation

• The progress in laser technology has led to
  light sources delivering pulses
• of femtosecond duration and focused
  intensities up to 1022 W/cm2

NOVA Laser (1999, LLNL, petawatt)
HERCULES (CUOS), Table Top Petawatt
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Introduction Motivation

• Experiments carried out in recent years on the
  laser-plasma interaction show the
  possibility of ions acceleration to high energy
  (tens of MeV)

• Compact and affordable ion accelerator based on
  laser produced plasmas
• have potential applications in many fields of
  science and medicine (radiography, isotopes
  generation, cancer therapy, inertial fusion).

• Two more studied mechanism of ion acceleration
  are TNSA (60MeV,
• energy spread 20), RPA ( 30 Mev, 50, ).

TNSA accelerating ions by ultra-intense laser
pulses

• The light pressure, P2I/c, from Gigabar to
  Terabar may compress plasma and generate shock
  waves that lead to acceleration of ions due to
  reflection by shock front (monoenergetic
  component in ion spectra are produced )

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Set -up
Foil full ionized H plasma
Foil size 3-20 ? Foil density
2-100 n, Laser pulse circular polarized
Amplitude a 2-50
4 ?lt R lt 10 ? 5 ?lt L lt 400 ? 5 ?lt X1lt 10
? 2 ?lt X2 lt 5? 2 ?lt X1 lt 10 ?
aeE/ mc?
asqrt(I/1.35 1018 Wcm -2 (?/µm) 2)
n 1.1 1021 cm-3, ?0.8 µm
HERCULES (MI), ATF BNL (NY), Sokol-P
(Snezhinsk, Russia)
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Numerical Model
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Numerical modelling is carried out on the basis
of code UMKA2D3V, allowing to carry out
calculations of interaction of laser radiation
with plasma of any complex structure and to
choose type of boundary conditions for an
electromagnetic field (reflection, absorption,
periodic conditions). The effective algorithm of
parallel calculations is created, and its
realization on multiprocessing complexes
MBC-15000 (Moscow) is carried out. At the
decision it was used 100-150 processors of
complex MBC-15000, calculation up to the moment
of time to the equal 400 laser periods has
occupied approximately 5000 hours of processor
time. Vshivkov V.A., Dudnikova G.I. Comput.
Technol., 2001.
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Channel caviton formation
Plasma formations observed in experiment (ATF
BNL) and simulated (bottom row) shadowgram and a
simulated plasma profile for case filamentation
and solitons for neltn, postsolitons for neltn
ne2n ne2.5 n
I. V. Pogorelsky, et.al, Proceedings of IPAC10,
Kyoto, Japan, 2010.
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Hole-boring and shock formation
V0.06 c
Vhb sqrt((1k) I / ?c) Cssqrt(kTe /mi)
Temc2sqrt(1a2/2)
M1.3
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Ion phase space
Ion trajectories
Distribution function
Palmer Charlotte A. J. Dover N. P. Dudnikova G.
I., et. al Phys. Rev. Lett. 106, 014801 (2011)
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Flat pulse
R-T instability
Ion density
Proton energy spectra
Ion energy phase space
T.C.Liu, G. Dudnikova, et.al, Phys.Plasma, 18,
2011
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Plasma density temporal evolution. a32, n169
n, d0.25 ? I1.4 10 21W/cm2, n1.9 10 23 cm-3,
d0.25 µm
a32
Energy spectrum
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Summary

• Laser acceleration is potentially an affordable
  alternative to traditional cyclotron
  acceleration. Intense, high quality ion beams
  driven by relativistic laser plasma - the next
  generation ion accelerators.
• Shock-like acceleration due to the ion
  reflection at the front of the compressed layer
  in the plasma lets to obtain the
  quasi-monoenergetic ion bunch.
• In realistic geometries there are two
  independent obstacles to sustain
  quasi-mono-energetic regime of acceleration
• Rayleigh-Taylor
  instability of plasma sheet
• lateral expansion of
  plasma