Bubble Acceleration with few-cycle

pulses

Max-Planck-Institut für Quantenoptik

Michael Geissler, Jörg Schreiber, Florian Grüner

and Jürgen Meyer-ter-Vehn

Outline

3D-PIC Simulations of:

few cycle pulses:

•Scaling

•Density Profile

•Closer look on “bubble-

electrons”

Experiments (Rutherford, Jena,

MPQ…)

3D-PIC Code for Ideal Laser Matter Interaction:

ILLUMINATION ILLUMINATION

Numerical Tool

Laser Pulse

y

x – Laser Polarization z – Propagation direction

5fs, a=5, w0=5µm, p=8µm

5fs, a=5

5fs, a=5, 70MeV e-

5fs, a=5, 60-80MeV e-

5fs, a=5, 60-80MeV e-

5fs, a=5, 60-80MeV e-

a=3

a=5

a=10

a=30

5fs, w0=5µm, p=8µm

5fs Summary

a=3 a=5 a=10 a=30

Epeak (80MeV) 80MeV 130MeV 310MeV

Lmax 300µm 220µm 250µm 500µm

Ezmax 0.5TV/m 1.1TV/m 1.6TV/m 2.3TV/m

ne,peak Etot,pea

k

1.2x109

14mJ3.8x109

75mJ24x109

1300mJ

5fs Scaling

125.025.0max ; IaRE Bubblez

5fs, a=5

with Gas denstity profile:

N0

z200µm 200µm

Focus position

5fs, a=5, p=8µm, profile

MPQ: 5fs, a=5, w0=2µm; 20mJ

RAL: 40fs, a=0.767, 390mJ

z [µm]

z [µm] z [µm]

Ez [1012V/m]

Ne [10201/cm³] Intensity [1019 W/cm²]

RAL: 40fs, a=0.767, 390mJ

Jena: 80fs, a=3

80fs, a=3

Ne [10201/cm³]

I [1019W/cm²]

Conclusions Few-cycle pulses are most efficent for bubble acceleration (longer pulses become few-cycle during propagation)

Acceleration is limited due:

•Rb=w0*a0.25 ~Eacc

•Short lifetime of the bubble (~200-400µm)

Precise control of gas density and length is necessary

Multistages:

Use a small amount (20-100mJ) in the first stage, but what afterwards?

Wakefield? second bubble? How to inject the electron?

40fs, a=3