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

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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

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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

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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

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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