plans for strong-field QED experiments at FACET-II€¦ · Institute #1 #4 #1 R. #4 R. ™ ™...

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plans for strong-field QED experiments at FACET-II

David A. ReisStanford PULSE Institute

Departments of Applied Physics and Photon Science

Physics Opportunities at a Lepton Collider in the Fully Nonperturbative QED Regime, August 7–9, 2019, SLAC

+"#

https://www.exhilp.org

Free registration until August 15

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FACET-II SFQED proposal collaboration* approved as E320

Collaborating Institutions: Carleton University (Canada), Aarhus University (Denmark). Ecole Polytechnique(France) Max-Planck-Institut für Kernphysik (Germany), Helmholtz-Institut Jena (Germany), Friedrich-Schiller-Universität Jena (Germany), Universidade de Lisboa (Portugal), Queen's University Belfast (UK), California Polytechnic State University (CA USA), Lawrence Livermore National Laboratory (CA USA), Princeton University (NJ USA), SLAC National Accelerator Laboratory (CA USA), University of California Los Angeles (CA USA), University of Colorado Boulder (CO USA), University of Nebraska - Lincoln (NE USA)

SFQED theory & simulation A. DiPiazza, F. Fiuza, T. Grismayer, C.H. Keitel, S. Meuren, L.O. Silva, D. Del Sorbo, M. Tamburini, M. Vranic

SLAC E144 DAR (SF AMO/xray), T. Koffas (HEP)

LWFA SFQED experiments G. Sarri, M. Zepf

Crystal SFQED experiments R. Holtzapple, U. I. Uggerhoj

Strong-field AMO/x-ray science P.H. Bucksbaum, M. Fuchs, C. Rödel

Laser-plasma interaction, HEDP F. Albert, S. Corde, S. Glenzer, C. Joshi, M. Litos, W. Mori

Accelerator physics G. White

Detectors A. Dragone, C. J. Kenney

High intensity lasers A. Fry

(*@submission)

QED Critical Field (“Schwinger Field”)

Sauter (1931), Euler, Heisenberg, Schwinger

2 lc

2mc2

E

Dirac sea

e-e+

• Materialize pairs when work done in

(reduced) Compton wavelength equal

rest mass

(four orders higher for µ+µ-)

• Exponentially suppressed E < Ecr

• Critical intensity for EM-field (peak):

• Need to also conserve momentum (not possible in single plane-wave)

Photonics Spectra, Nov. 1997

Ecr =m2c4

e~c = 1.3⇥ 1016V/cm

eEcr�̄c = mc2

Icr = 4.6⇥ 1029W/cm2

Invariant field strength (classical and quantum parameters)

⌘ =e

mc2

qhAµAµi = eE�

2⇡mc2

⌥ =e~

m3c5

qh(Fµ⌫p⌫)2i =

eE⇤�c

2⇡mc2= ⌘

�c

�⇤

$∗ = $ 1 + ()

*+ = $,)( 1 + () − 1)Note as defined here E is rms value to be independent of polarization. for strong-fields and linear polarization peak value often used

Leads to time-averaged effective mass and ponderomotive energy:

−

- Ip

Photoionization/linear Breit-Wheeler

Above threshold

- Ip

TunnelingSchwinger breakdown

High-field, low frequency

e(-aΥ)

- Ip

Multi-photon IonizationNonlinear Breit-Wheeler

High field, below threshold

~ η(2n)

Transition depends on both field and frequency

⌘ = ⇠ = a0 =eE

m!c,⌥ = � =

E

Ec

Analogy: regimes of atomic ionization

Non-linear/non-perturbative QED

= + + + + · · ·

Exactly solvable in terms of dressed state (Furry, Volkov, …)

e!

e+

! k"µ

pµ

1

pµ

2

Photon emission

Multi-photon ComptonQuantum radiation reaction…

Photon decay

Multi-photon Breit-Wheeler Pair production“Schwinger” pair production…

⌘ =e

mc2

qhAµAµi = eE�

2⇡mc2⌥ =

e~m3c5

qh(Fµ⌫p⌫)2i =

eE⇤�c

2⇡mc2= ⌘

�c

�⇤-

See e.g. Reiss 1962, Nishikov and Ritus , 1963, Narozhni, Nishikov and Ritus, 1965…

pµ

k!µ

p!µ012

02

032

042

02 = 52 + 672 , 6 = ()$)

2(75)0) = $∗)

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How produce such high intensities?

50 GeVE-field is not Lorentz-invariant. boosted by

4g2 intensity 2g field

in electron’s frame

E144 reached U ~ 0.3, h ~ 0.3 (rms)

Bucksbaum et al., 2018 NAS Report, …reaching the brightest light

LCLS*

*LCLS @ ~1Å

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How produce such high intensities?

D. Strickland and G. Mourou, “Compression of amplified chirped optical pulses”, Opt. Commun. 56, 219 (1985)

1/2 of 2019 Physics Nobel

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Focused Intensity Frontier

20TW/13GeVFACET-II (E320)

20TW(lab frame)

50 GeV

Y >1 possible nowwith current facilities (SLAC/DESY…)…and modest laser

Front row: G. Horton-Smith, Th. Kotseroglou, W. Ragg, S. BoegeMiddle row: D. Meyerhofer, W. Bugg, A. Weidemann, D. Walz, J.Spencer, K.McDonald, A. MelissinosLast row: K. Shmakov, C. Bamber, U. Haug, D.Burke, C.BulaAbsent: S. Berridge, C. Field, Th. Koffas, E. Prebys, D.Reis

E144 experiment: nonlinear QED in laser+e- collisions

D.L.Burke et al, PRL79 1626(1997) C.Bamber et al, Phys.Rev. D60 090024(1999)

E144: 1st experiment in nonlinear QED (laser+ ultrarel. e- collisions)

Bula et al., PRL 1996, Burke et al., PRL 1997, Bamber et al., PRD. 1999

n=1

n=4

FFTB (now LCLS transport)

e + nw à e’ +w’ q+nk = q’ +k’

Calculations: h= 0.6, l=1054nm, circ. polarization.1J , A= 50µm2 , t=1.88 ps, 5•109 e- in 60x60x870µm3 (rms)

Nonlinear Compton Scattering

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(a)

t [psec]

x [µ

m]

(a)

t [psec]

x [µ

m]

(b)

-200

-100

0

100

-10 -5 0 5 10-200

-100

0

100

-10 -5 0 5 10

N1/Ng N2/Ng

Pert. NLC and finding overlap (t,x)

e- + Nw à e-’ +w’w’+nw à e+ + e-

q+Nk = q’ +k’k’+nk = e++e-

Most probably N=1, n=4–5 for IR

Background: non-sequential trident e- + nw -> e-’ +e+ + e-

Estimated to be 2–3 orders of magnitude lower, no theory at the timen=5–6

Nonlinear Breit-Wheeler pair production

Threshold, :;;1 = $∗)

e- + Nw à e-’ +w’w’+nw à e+ + e-

q+Nk = q’ +k’k’+nk = e++e-

Most probably N=1, n=4–5 for IR

n=5–6

Nonlinear Breit-Wheeler pair production

Threshold, :;;1 = $∗)

See e.g. Hu, Müller, Keitel, PRL 105, 080401 (2010)

Strong-field trident:

Threshold, < 1 − = ; = 4$∗

Also, Ilderton, PRL (2011) …

0

10

20

30

40

10 15 20

N(e

+ ) per

2 G

eV/c ON

OFF(a)

0

5

10

15

20

10 15 20

dN(e

+ )/dp

[1/G

eV/c] (b)

0

5

10

15

20

10 15 20positron momentum [GeV/c]

ONOFF

(c)

0

5

10

10 15 20positron momentum [GeV/c]

(d)

h>0.216

h>0.216

106±14 signal out of ~22k shots

69±9 signal out of ~22k shots

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E144 Measured in transition regime

19Multi-photon picture

Tunneling Picture (Schwinger)

Υ = E/Ec

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Anomalous 2-photon X-ray Compton, Be@1020 W/cm2. (h~10-3, U~10-5)

Fuchs et al., Nature Physics, 2015

-0.4! 0! 0.4! 0.8 ! 1.2! 1.6!

minimum redshift [keV]!-0.4! 0! 0.4! 0.8 ! 1.2! 1.6!

minimum redshift [keV]!

Low Intensity (2ω;$n=1)$High-Intensity (ω+ω;$n=2)$

-0.4! 0! 0.4! 0.8 ! 1.2! 1.6!




! + ! ! !K(18 keV)

High Intensity n=2,w+w Low Intensity n=1, 2w

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Anomalous 2-photon X-ray Compton, Be@1020 W/cm2. (h~10-3, U~10-5)

-0.4! 0! 0.4! 0.8 ! 1.2! 1.6!




But, semiclassical+QED/TDSE: no anomaly. Krebs, DAR, Santra, PRA, 2019

Additional missing momentum on order Z/a0

Proposed mechansismcombined scattering and absorption

Red-shift incompatible with free-electron or atomic impulse response

Fuchs et al., Nature Physics, 2015

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E320 on FACET-II will test various aspects of SFQED

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Laser Parameter Table

!1

Function Present Optimal Present

40 TW(Gratings set

limit)100 TW

(Pump sets limit)Limits?Why?

UpgradesDazzler/Wizzler

Deformable Mirror

Dazzler/etcDeformable

MirrorGAIA

Gratings

Dazzler/etcDeformable Mirror

GAIA-HPCompressor Box

Power-amp Pump [J] 2.8 3.6 7.5 16.0

Power-amp Output [J] 0.6 1.1 2.3 4.8 30% from pump to output

Beam Transport Input [J] ? 1.0 2.0 4.3 90% Expected due to polarizer

Compressor Input [J](beam transport output) 0.4 0.9 1.8 3.9

65% measured at FACET90% Expected from transport

input to compressor (11 optics @ 99%, 21 optics at 99.5%)

Beam Size @ Compressor

4 cm diameter150 ps fwhm




1.8 J@ 6 cm max input measured at MEC ?? ps

Compressor Output [J] 0.25 0.61 1.28 2.72 65% measured at FACET70% expected

Pulse Duration (fwhm) [fs] 70.0 35.0 35.0 35.0 <40 fs requires spectral

shaping

Peak Power [TW] 3.6 17.5 36.5 77.8

Intensity* [1018 W/cm^2] 23.7 116.3 242.4 517.0 3 um focus

a0* 3.3 7.3 10.6 15.4 3 um focus

Upgrade $** 0.0 50+100+100 100+100+400+25 100+100+400+Comp

*Intensity and a0 based on document sent around by Sebastian

FACET-II laser expected performance

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Reaching strong-field regime @FACET-II

Baseline: 20 TW, 10 GeV

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0.1 1 10 100

a0

0.1

1

10¬

10Ge

V

7Ge

V15Ge

V20

GeV

30Ge

V

1Ge

V2Ge

V

LWFA

E144E144

1020 W/cm2

1021 W/cm2

1019 W/cm2

fullquantumregime

moderatequantumregime

classicalregime

laser:perturbation

laser:nonperturbative

Reaching strong-field regime @FACET-II

U,c

h,x,a0

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Reaching strong-field regime @FACET-II. 20 TW laserSFQED@FACET-II: baseline setup (20 TW laser)

Major scientific objectives

Unstable strong-field quantum vacuum

≠æ first observation of tunneling pair production (≥ 103 pairs per shot)Quantum radiation reaction

≠æ failure of the classical Landau Lifshitz equation, quantum stochasticityBreakdown of perturbation theory

≠æ absorption of ≥ 102 laser photons, emission of ≥ 5 photons (per electron)

Electron spectrum

2 4 6 8 10electron energy [GeV]

10�4

10�3

10�2

10�1

100

prob

abili

ty[a

.u.]

2 4 6 8 1010�4

10�3

10�2

10�1

100

simul

atio

n:M

.Tam

burin

i

– Quantum radiation reaction: stochasticity– Deviations from Landau Lifshitz (dotted)

Photon spectrum

10�2 10�1 100 101

photon energy [GeV]

10�3

10�2

10�1

100

inte

nsity

[a.u

.]

10�2 10�1 100 10110�3

10�2

10�1

100

simul

atio

n:M

.Tam

burin

i

– Highly nonlinear Compton scattering– Local constant field approx. fails (dotted)

Sebastian Meuren (Princeton University) 7 / 10 Probing SFQED with Ultraintense Laser

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Beamline layout (~IP to dump)

E-320 (SFQED)Phase 1, e- + e+ spectrometer + diagnostics

Phase 2, add gamma spectrometer

Phase 3-X, multi-color, upgraded laser? second IP for Gamma + laser…

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SFQED@FACET-II

w =1.55 eV, h = 17, U= 3

w =1.55 eV, h = 17, U= 1.6w =4.8 eV, h <<1, Y = 0

w =1.55 eV, h <<1, U = 0, circ pol.

strong-field Compton, quantum rad. reaction

strong-field Pair production

Vacuum birefringence

w =1.55 eV, h < 17, U< 0.4

Precision measurement using 100 TW, focused to 4µm

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“New” physics: re-collisions.

( ≫ 1, Υ ∼ 1, Stationary phase approximation, Tunneling, classical trajectories, re-collisions similar to SF-AMO

Possiblity for B4 + µ3, D4 + D3; DF… productions well below threshold

S. Meuren, thesis Heidelberg 2015

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And then what…

New facility in research yard or LCLSMulti-PW laser (already planning on MEC, but w/o conventional ultra-rel. Beam)Gang 2nd and 3rd km -> 30GeV, nm, fs beamsafterburner-> 60 + GeVx-rays…

100GeV collider?

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Acknowledgments

• FACET-II SFQED collaboration (S. Meuren et al.)

• E144 collaboration, (especially K. McDonald, A. Melissinos, T. Koffas)

• SFQED@SLAC working group: (DAR, P. Bucksbaum, T. Abel, R. Blandford, F. Fiuza, S. Glenzer, M. Hogan, V. Yakimenko, Z. Huang, C. Pellegrini, A. Fry, S. Brodsky, S. Meuren)

(DAR, PHB: FES, SM: HEP/FES)

plans for strong-field QED experiments at FACET-II€¦ · Institute #1 #4 #1 R. #4 R. ™ ™...

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