High Energy Density Physics with UltraRelativistic Beams

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Ron Davidson Symposium June
12, 2007 Celebrating 40 years of plasma physics
research and education
High Energy Density Physics with
Ultra-Relativistic Beams T. Katsouleas Universit
y of Southern California
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Ron Davidson, the teacher of generations11 Books
bridging classroom to researche.g., solitons in
Methods in Nonlinear Plasma Theory (Academic
Press, 1972)
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R. Davidson et al., 2003
The universea place of titanic violence and
continuous upheavalpowered by the twin engines
of gravitational collapse and nuclear fusion.
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Intense Relativistic Beams in Plasmas
PW/m2Rich Physics

• Wake generation/ particle acceleration
• Focusing
• Hosing
• Collective Refraction
• Radiation generation
• Ionization

• Compact accelerators
• Plasma lens/astro jets
• Ecloud instability/LHC
• Fast kicker
• Tunable light sources
• New physics

Ron Davidson and Hong Qin, Physics of Intense
Charged Particle Beams in High Energy
Accelerators, World Scientific (2001)
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3-D simulation of particle beam refracting as it
exits plasma (blue)
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Electron Beam Refraction At PlasmaGas Boundary
Asymmetric Channel Beam Steering
Symmetric Channel Beam Focusing
Head
q
Core
f












rca(nb/ne)1/2rb































e-







Plasma, ne
qµ1/sinf
Vary plasma e- beam angle f using UV
pellicle Beam centroid displacement _at_
BPM6130, 3.8 m from the plasma center
qf
o BPM DATA
Impulse Model
P. Muggli et al., Nature 411, 2001
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High power beams tend to blow holes

• 30 GeV e-beam penetrates several mms of copper

Courtesy T. Raubenheimer, M. Ross
But we have seen

• 30 GeV beam incident on 1mm of dilute gas
  (one million times less dense than air) refracts
  and even...bounces off (total internal
  reflection)!

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Electron-Cloud Instability in Circular
Accelerators A 54000km non-neutral beam-plasma
interaction!
R. Davidson w/ H. Volk Garden-hose instability,
PF (1968)

• E-cloud formation(Positron) Synchrotron
  radiationSecondary Emission
• E-cloud formation (Proton)
• Halo effectSecondary Emission
• E-Cloud is observed in CERN SPS
• and PS, SLAC and KEK B factories
• Major concern in LHC Design.

• Ali Z. Ghalam, T. Katsouleas, A. Z. Ghalam, B.
  Feng (USC), W. B. Mori, C. Huang, V. Decyk, C.
  Ren(UCLA)
• Giovanni Rumolo, Frank Zimmermann, Francesco
  Rugierro (CERN)

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Circular Accelerators and Electron
Cloud(Continued)
CERN(Geneva)
Spot size growth in horizontal plane for LHC (A.
Ghalam et al, 2004)
Beam Density in Horizontal Plane
Z
Y

• SPS is a 7Km long Super Proton Synchrotron.
• Accelerates protons and anti protons to 450Gev
• Average electron cloud is 1e6/Cm3
• Instability of the same type of LHC is observed

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Role of Wavebreaking in Plasma Accelerators
Self Modulated Laser Wake Field
Accelerator
Wave Breaking
Laser
Self Trapped Plasma Electrons
Plasma lexicon calls this wavebreaking or
particle trapping
T. Katsouleas, Nature 2004 E. Oz et al., PRL 2007
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Using Wavebreaking to Make a Brightness
Transformer

• Unprecedented phase space densities
• Novel coherent light sources (e.g., X-ray FELs)

Coherent radiation generation R. Davidson w/ Y.
Z. Lin, Phys. Rev. A (1984)
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OSIRIS SIMULATION RESULTS
Peak at 11 GeV
FWHM 4
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OSIRIS SIMULATION of TRAPPED BEAM ACCELERATION
I
Ez
He/Li Profiles
dN/dE
z
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Evidence for a Brightness Transformer in the SLAC
PWFA Experiment (E-167)
drive beam
E
trapped beam
y
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Plasma Afterburners for a Linear Collider
0-50GeV in 3 km 50-100GeV in 30 m
3 km
Afterburners
30 m
S. Lee et al., Phys. Rev. STAB, 2001
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e- e Beams--Plasma Response
3-D QuickPIC simulations, plasma e- density
sr35 µm
sr700 µm
N1.8?1010
d2 mm
e- ne02?1014 cm-3, c/wp375 µm
e ne02?1012 cm-3, c/wp3750 µm
Uniform focusing force (r,z)
Non-uniform focusing force (r,z)
P. Muggli
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Beam Loading of Positrons on an Electron Wake

• Returning plasma e- s create density
  concentration region
• focusing field for e
• accelerating field for e, same order of
  magnitude for e-
• But accelerating e and e- in the same RF bucket
  is problematic
• (e.g., safety damping dipoles point to ground for
  only one)
• would need dedicated e source

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Plasma as a Magic Converter/Filter
X. Wang et al, in preparation
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OSIRIS Simulations of Plasma e Converter/Filter
S1.90cm
S4.55cm
r
Wake
z
r
e-
r
Pure e bunch
e
z
z
High density witness e- bunch is defocused by
plasma wakefield excited by relative low
density e- driving bunch Pure e bunch
remains Opens a new arena for Ron nonlinear
positron-plasma interactions
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To my parents I owe my life. To my teacher I
owe my love of life. --Alexander the
Great Thank you Ron for adding so much to the
love of life for so many.
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3-D Plasma density response to a flat beam
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Refraction of an Electron Beam Interplay Between
Simulation Experiment
1 to 1 modeling of meter-scale experiment in
3-D! (128 processors at NERSC, 5000 cpu hours)
P. Muggli et al., Nature 411, 2001