Perspectives of Plasma-Wakefield Acceleration

• basics• perspectives• state-of-the-art• brief overview of various projects

F. Grüner, Universität Hamburg & Center for Free-Electron Laser Science

basic principle of any accelerator

one needs an electric field…

charge separation

+ -

electron

-

…charged particles are then accelerated

First X-ray FEL (2009):Stanford, USA

kilometer long!!!!....

accelerators can be quite large…

plasma cell:cm short!!!!....

but also quite small…

lab setup of a Laser-Plasma-Accelerator at MPQ (S. Karsch et al.) pulse of a high-Power laser

plasma wakefield acceleration

high-intensitylaser:~ 5 J / 25 fs

plasma(capillary)

laser pulse withrelativistic intensity

typical length scale = plasma wavelength

wake

plasma

Ez ~ TV/m

~ 5 fs

PIC simulation (M. Geissler)

• EuroNNAc workshop @ CERN, May 2011, top 5 goals, among them

- „table-top“ XFEL- 10 GeV stage- stable operation 24/7

• brilliant X-ray sources „at home“, added values:

- intrinsic synchronization (driver laser, X-ray pulse, few fs)- compact enough for hospitals: medical applications- higher peak currents (above 20 pC/4 fs)

• high-energy physics

- TeV machine- sure enough, many open questions (emittance growth, staging,

timing/pointing for ~100 stages, efficiency,…..)

perspectives

Leemans & Esarey, Physics Today, March 2009

~ 16 m

• before 2000: theory on LWFA, experiments with „thermal“ energy spectra

• 2000 theory of bubble acceleration (Meyer-ter-Vehn & Pukhov, MPQ): needs stronger laser

• 2004 first experimental results, peaked energy spectra (LBNL, LOA, RAL, Nature)

• 2006 Berkeley lab reaches 1.0 GeV (W. Leemans et al., Nature Physics)

• 2008 stability improvement (e.g., J. Osterhoff et al., PRL)

• 2009 first laser-driven soft X-ray undulator source (F. Grüner et al., Nature Physics)

• 2010-… diagnostics: bunch length, emittance, position behind laser new injection schemes: down-ramp, counter-propagating lasers, ionization, shock-front

state of the art

courtesy of S. Karsch

open questions how does it all work?

• key questions- emittance growth- energy spread- injection- beam loading- exit into vacuum- staging scalable?

• selft-consistent analytical treatments too complex → PIC codes

• but: PIC codes suffer from- idealistic modelling- numerical heating- resolution issues (space charge)

PWA worldwide

LOALOA

Imperial CollegeRutherford Lab

StrathclydeOxford

Imperial CollegeRutherford Lab

StrathclydeOxford

DüsseldorfJena

DresdenMunich

Hamburg

DüsseldorfJena

DresdenMunich

Hamburg

JAEA, NaraJAEA, Nara

APRIAPRI

LundLund

BerkeleyLincoln

Ann ArborAustin

Livermore

BerkeleyLincoln

Ann ArborAustin

Livermore

BejingShanghai

…

BejingShanghai

…

FrascatiFrascati

research clusters in Germany

name start run time partners

TransRegio 18 2004 3 x 4 years Düsseldorf,Jena, LMU, MPQ, MBI

MAP Cluster of Excellence

2006 5+1 years follow-up proposal 2011

LMU, MPQ, TUM

Helmholtz Association: ARD

2011 2011-2015, then PoF3 HZDR, DESY, HI Jena, UHH, CFEL

CALA 2011 new university institutebuilding ready, start 2013

LMU, TUMLMU,

MPQ

MBI

Düssel-

dorfJena

HZDR

DESY, UHH/CFEL

Düsseldorf(Oswald Willi et al.)

Düssel-

dorf

lasers 10 TW + 100 TW + 200 TW (25 fs)all synchronized

planned upgrades: 100 → 200 TW; XPW (1012

contrast)

current electron beams

gas jets: 330 MeVgas targets (5-15 mm): stable 110 MeV

research testing microchips for outer spacestaging of plasma acceleratorstheory + simulations

Jena(Malte Kaluza et al.)

lasers JETI: 32 TW (25 fs) on target, plasma mirrors for >1012 contrast

planned upgrade: 2012 2.5 J

current electron beams

300 MeVenergy spread 1-2 %charge 1-15 pC

research light sources (THz, betatron, undulator)cell irradiatione-beam diagnostics (with MPQ)

highlight direct observation of electrons inside bubble

Jena

M. Kaluza et al., PRL 2010

A. Buck et al., Nature Phys. (2011)

Max-Born Insitute (Berlin)(Matthias Schnürer et al.)

lasers 100 TW (25 fs) coupled with 30 TW (45 fs)

current electron beams

so far ion accelerationelectrons start in 2012

research (plasma) pump (ion/photon) probe experimentsstaging of plasma accelerators

highlight record efficiency for laser into ion energy

MBI

HZDR (Dresden)(Ulrich Schramm et al.)

HZDR

lasers 150 TW (25-30 fs)

upgrade: 500 TW (25-30 fs), 2012 1 PW end of 2013

current electron beams

so far ion accelerationelectron acceleration started; joint experiments with DESY/UHH

research injection of external ELBE beam (100 fs)

LMU/MPQ (Munich)(S. Karsch, L. Veisz, F. Grüner, et al.)

lasers ATLAS: 100 TW (25 fs, Ti:Sapph)LWS-20: 16 TW (8 fs, OPCPA)

planned upgrades: LWS-100 (5 fs)ATLAS-3000, PFS: 5J/5fs/1kHz (in CALA)

current electron beams

LWS-20: 20-40 MeV, 5-6 fs (measured)ATLAS: >500 MeV, >100 pC

research e-beam diagnostics (bunch length, emittance)light sources (undulator, table-top FEL design, medical imaging)theory + simulation

highlight highly stable 200-600 MeV electronsfirst laser-driven soft X-ray undulator source

LMU,MPQ

M. Fuchs,…, J. Osterhoff, …,S. Karsch, F. Grüner, Nature Phys. 5, 826 (2009)

LAOLA = DESY+UHH+CFEL(laola.desy.de)

DESY, UHH, CFEL

laser March 2013: 200 TW (5J / 25 fs)

planned projects

combining modern accelerators with PWA:

• beam-driven self-modulation (PITZ)• transformer ratio studies (PITZ+FLASH)• external injection (REGAE+FLASH)

cooperations • ARD (Dresden+Jena)• MAP• SLAC + Berkeley• MBI• MPP• JAI

summary

• PWA emerging field: ultra-high gradients + ultra-short bunches

• perspectives: compact light sources, high-energy colliders…..

• still many open question: beam quality…

• increasing national and international activities

• merging with conventional, modern accelerators