High Energy Density Physics with Ultra- Relativistic Beams T. Katsouleas University of Southern...
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Transcript of High Energy Density Physics with Ultra- Relativistic Beams T. Katsouleas University of Southern...
High Energy Density Physics with Ultra-Relativistic Beams
T. Katsouleas
University of Southern California
Ron Davidson Symposium June 12, 2007Celebrating 40 years of plasma physics research and education
Ron Davidson, the teacher of generations11 Books bridging classroom to research
e.g., solitons in Methods in Nonlinear Plasma Theory (Academic Press, 1972)
“The universe…a place of titanic violence and continuous upheaval…[powered by] the twin engines of gravitational collapse and nuclear fusion….”
R. Davidson et al., 2003
Intense Relativistic Beams in Plasmas:
PW/2
Rich 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)
3-D simulation of particle beam refracting as it exits
plasma (blue)
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
-8 -4 0 4 8
05190cec+m2.txt 8:26:53 PM 6/21/00impulse model
BPM data
θ
( )mrad
φ ( )mrad
θ1/sin
θ≈o BPM DATA
Impulse Model
rc=(nb/ne)1/2rb
θ
Head
Plasma, ne
AsymmetricChannel
Beam Steering
SymmetricChannel
Beam Focusing
e-++
++
++++
++++
++++
++++
++++
++++
++++
++++
++++
+++++ + ++++- - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Core
Electron Beam Refraction At Plasma–Gas Boundary
P. Muggli et al., Nature 411, 2001
• Vary plasma – e- beam angle using UV pellicle
• Beam centroid displacement @ BPM6130, 3.8 m from the plasma center
• 30 GeV e-beam penetrates several mm’s of copper…
• 30 GeV beam incident on 1mm of dilute gas (one million times less dense than air) refracts and even...bounces off (total internal reflection)!
High power beams tend to blow holes
But we have seen…
Courtesy T. Raubenheimer, M. Ross
Electron-Cloud Instability in Circular Accelerators: A 54000km non-neutral beam-plasma interaction!
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) U C L A
+
-
SynchrotronRadiation
SecondaryEmission
Circularmachine
Positron Bunch
• E-cloud formation(Positron): Synchrotron radiation+Secondary Emission
• E-cloud formation (Proton): Halo effect+Secondary Emission • E-Cloud is observed in CERN SPS and PS, SLAC and KEK B factories • Major concern in LHC Design.
R. Davidson w/ H. VolkGarden-hose instability, PF (1968)
Circular Accelerators and Electron Cloud(Continued) Circular Accelerators and Electron Cloud(Continued)
CERN(Geneva):Spot size growth in horizontal plane for LHC (A. Ghalam et al, 2004)
• 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
QuickTime™ and aVideo decompressor
are needed to see this picture.
Beam Density in Horizontal Plane
Y
Z
Role of Wavebreaking in Plasma Accelerators
Wave Breaking
Plasma lexicon calls this wavebreaking or particle trapping
Self Modulated Laser Wake Field Accelerator
Laser
Self Trapped Plasma Electrons
T. Katsouleas, Nature 2004; E. Oz et al., PRL 2007
e- beamdriver
Plasma Source:neutral Li vapor confined by He
Trapped bunch
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)
-200 0 2000
10
20
I (kAmp)
z ()
2 4 6 10x 4
0
5
10
Pz ( )mc
Number of Particles
-20 0 200
1
2
3
4
5
6
7
Pr ( )mc
Pz
(x10
4 mc)
OSIRIS SIMULATION RESULTS
Trapped
Bunch
Driver
Ipeak (kA) 20 9
FWHM 2 65
Emittance
(mm-mrad)
5 50
Bn (A/m2) 1.5x1015 7x1012
FWHM ~%4Peak at 11 GeV
QuickTime™ and aH.264 decompressor
are needed to see this picture.
OSIRIS SIMULATION of TRAPPED BEAM ACCELERATION
I
dN/dE
Ez
He/Li Profiles
z
e- beamdriver
Plasma Source:neutral Li vapor confined by He
Trapped bunch
Evidence for a Brightness Transformer in the SLAC PWFA Experiment (E-167)
Energy [GeV]
04042de #19
100 150 200
42
27
20
16
13
E
y
trapped beam
drive beam
Plasma Afterburners for a Linear Collider*
Afterburners
3 km
30 m
*S. Lee et al., Phys. Rev. STAB, 2001
0-50GeV in 3 km50-100GeV in 30 m*
e-: ne0=21014 cm-3, c/p=375 µm e+: ne0=21012 cm-3, c/p=3750 µm
r=35 µmr=700 µm
• “Uniform”focusing force (r,z)
=1.81010
• Non-uniformfocusing force (r,z)
d=2 mm
3-D QuickPIC simulations, plasma e- density:e- & e+ Beams--Plasma Response
e- e+
P. Muggli U C L A
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
Beam Loading of Positrons on an Electron Beam Loading of Positrons on an Electron Wake Wake
++++++++++++++ ++++++++++++++++
----- --- ----------------
--------------
--------- ----
--- -------------------- - --
---- - -- ---
------ -
- -- ---- - - - - - ------ - -
- - - - --- --
- -- - - - - -
---- - ----
------
electron beam
+ + + + + + + + + + ++ + + + + + + + + + + + + + ++ + + + + + + + + + + + + + +
+ + + + + + + + + + + + + + +-
- --
--- --
EzEz
ErErAccelerating and focusing for e+Accelerating and focusing for e+
Plasma as a Magic Converter/FilterPlasma as a Magic Converter/Filter
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
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ee--
ee-- ee--
ee++
22 11 2’2’ 1’1’
Plasma wakePlasma wakePhasing chosen so thatPhasing chosen so that
Region 2 focus for eRegion 2 focus for e--,, defocus for edefocus for e++
Region 1 defocus for eRegion 1 defocus for e++
e+
e+
Plasma
Ta converter
X. Wang et al, in preparation
QuickTime™ and aTIFF (Uncompressed) decompressor
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QuickTime™ and aTIFF (Uncompressed) decompressor
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High density witness e- bunch is defocused by plasma wakefield excited by relative low density e- driving bunchPure e+ bunch remains
Opens a new arena for Ron: nonlinear positron-plasma interactions
S=1.90cm S=4.55cm
OSIRIS Simulations of Plasma e+ Converter/FilterOSIRIS Simulations of Plasma e+ Converter/Filter
Wake
e-
e+
r
z
r
r
z z
Pure e+ bunch
“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.
ξ∂Ψ∂
−=zE
e- : Preionized
e- : Ionized inside the wake
Ψ
-Vpξ
ξmin
ξ
zE
ξmax
ξp
LongitudinalWake Amplitude
Potential Ψz
ctz −=ξ
Just like marbles rolling over a hill, It’s easier to turn the marble starting at the bottom around
Vp: Plasma Wake Phase Velocity
Wavebreaking in an ionizing plasma
E. Oz et al., PRL 2007
3-D Plasma density response to a flat beam
Refraction of an Electron Beam:Interplay Between Simulation & Experiment
Laser off Laser on
3-D OSIRIS
PIC Simulation
Experiment(Cherenkov
images)
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