High Energy Density Physics with Ultra- Relativistic Beams T. Katsouleas University of Southern California Ron Davidson Symposium June 12, 2007 Celebrating 40 years of plasma physics research and education

Ron Davidson, the teacher of generations 11 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)

 1/sin  ≈≈ o BPM DATA Impulse Model r c =  (n b /n e ) 1/2 r b   Head Plasma, n e Asymmetric Channel Beam Steering Symmetric Channel Beam Focusing e-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 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 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. Volk Garden-hose instability, PF (1968)

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/Cm 3 Instability of the same type of LHC is observed 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- beam driver 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)

OSIRIS SIMULATION RESULTS Trapped Bunch Driver I peak (kA)209 FWHM  265 Emittance (mm-mrad) 550 B n (A/m 2 )1.5x x10 12 FWHM ~%4 Peak at 11 GeV

OSIRIS SIMULATION of TRAPPED BEAM ACCELERATION I dN/dE Ez He/Li Profiles z

e- beam driver Plasma Source: neutral Li vapor confined by He Trapped bunch Evidence for a Brightness Transformer in the SLAC PWFA Experiment (E-167) E y trapped beam drive beam

Plasma Afterburners for a Linear Collider* Afterburners 3 km 30 m *S. Lee et al., Phys. Rev. STAB, GeV in 3 km GeV in 30 m*

e - : n e0 =2  cm -3, c/  p =375 µme + : n e0 =2  cm -3, c/  p =3750 µm  r =35 µm  r =700 µm “Uniform” focusing force (r,z)  =1.8  Non-uniform focusing force (r,z) d=2 mm 3-D QuickPIC simulations, plasma e - density: e - & e + B eams-- Plasma Response e-e- 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 Wake

Plasma as a Magic Converter/Filter e-e-e-e- e-e-e-e- e-e-e-e- e+e+e+e+ 21 2’1’ Plasma wake Phasing chosen so that Region 2 focus for e -, defocus for e + Region 1 defocus for e + e+e+ e+e+ Plasma Ta converter X. Wang et al, in preparation

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 S=1.90cm S=4.55cm OSIRIS Simulations of Plasma e+ Converter/Filter Wake e- e+ r z r r zz 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.

e - : Preionized e - : Ionized inside the wake -V p   min   max pp Longitudinal Wake Amplitude Potential  z Just like marbles rolling over a hill, It’s easier to turn the marble starting at the bottom around V p : 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