Proton-driven Plasma Wakefield Acceleration

1. Why proton-driven PWA ?2. What can be achieved in the future with PDPWA ?3. What can we do today – proposed experiment at CERN4. Who is interested/time scale

Allen CaldwellMax-Planck-Institut für PhysikEuroNNAC Workshop, CERN

May 4, 2011

May 4, 2011 1EuroNNAC

Why Proton-Driven PWA?We know how to produce high energy/particle and high bunch energies

with protons today, so if we can use protons to drive an electron bunch we could potentially have a simpler arrangement - single stage acceleration.

Linear regime (nb<n0):

Need very short proton bunches for strong gradients. Today’s proton beams have

2May 4, 2011 EuroNNAC

Proton-driven plasma wakefield acceleration (PDPWA)

A. Caldwell, K. Lotov, A. Pukhov, F. Simon, Nature Physics 5, 363 (2009).

p+e-

600 GeV e- beam ≤1% ΔE/Ein ~500 plasma

Drive beam: p+

E=1 TeV, Np=1011

σz=100 μm,σr=0.43 mmσθ=0.03 mrad, ΔE/E=10%

Witness beam: e-

E0=10 GeV, Ne=1.5x1010

Plasma: Li+

np=6x1014cm-3

External magnetic field:Field gradient: 1000 T/mMagnet length: 0.7 m

May 4, 2011 3EuroNNAC

A. Pukhov, U. Düsseldorf, VLPL

1 TeV

Energy

Phase

4

K. Lotov (Budker Institute, Novosibirsk) LCODE

May 4, 2011 EuroNNAC

G. Xia (MPP)

5May 4, 2011 EuroNNAC

Too long – use in combination with other compression schemes

6May 4, 2011 EuroNNAC

7Simulation: W. Lu, OSIRIS code (UCLA/Tsinghua U.)

May 4, 2011 EuroNNAC

Modulation of long bunch instead of bunch compression

Demonstration experiment on PDPWA

• kick-off meeting-PPA09 held at CERN December 2009• A spare SPS tunnel for demonstration experiment located• Large group of interested institutes• Letter of Intent to CERN under preparation

May 4, 2011 8EuroNNAC

CERN has expressed interest in hosting project, tunnel and experimental area identified

9May 4, 2011 EuroNNAC

May 4, 2011 10EuroNNAC

• Initial goal is to observe the energy gain of 1 GeV in 5 m plasma.• A plan for reaching 100 GeV within 100 m plasma will be developed

based on the initial round of experiment

Expected Results:A long SPS drive beam (without compression) will be used in the first experiment. A self-modulation of the beam due to the transverse wakefield occurs which produces many ultrashort beam slices.

Particle-in-cell simulations have been performed to look at electron acceleration:

C. Huang, Los Alamos Nat. Lab.

A. Pukhov, Heinrich Heine University, Düsseldorf

May 4, 2011 11EuroNNAC

The modulation resonantly drives wakefield in the 100-1000 MV/m with CERN SPS beam.

EuroNNAC 12May 4, 2011

Plasma Cell ideas:

Metal vapor, a la SLAC experiment:UCLA, Max Planck Institute for Physics

Discharge: IST, Imperial College

Helicon – Max Planck Institute for Plasma Physics

EuroNNAC 13May 4, 2011

Diagnostics:

Electro-optical sampling for modulations, field strength:University College, RAL, DESY Imperial College, Cockroft Institute, Strathclyde

Coherent transition radiation

Electron spectrometer:CERN, Imperial College, Cockroft Institute, Strathclyde

Simulation of long electron bunch, optimal SPS beam:J. Vieira, IST

May 4, 2011 14EuroNNAC

Time scale:

Submit LoI for consideration by SPSC in few weeks

Develop technical plan til mid 2012

Build components/installation of beamline til mid-end 2014

Start experimentation 2015

So far, everyone interested has been welcome !

Demonstration experiment based on modulation of SPS proton bunches will generate many exciting results.

Long term prospects for modulated proton bunch intriguing:

K. Lotov – simulation of existing LHC bunch in plasma with trailing electron bunch …

Proton energy loss/gain

Electron energy gain

May 4, 2011 15EuroNNAC

Miracle: no guiding magnetic fields necessary !