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Max-Planck-Institut für Quantenoptik
Bubble Acceleration with few-cycle pulses
Michael Geissler, Jörg Schreiber, Florian Grüner
and Jürgen Meyer-ter-Vehn
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Outline

• 3D-PIC Simulations of
• few cycle pulses
• Scaling
• Density Profile
• Closer look on bubble-electrons
• Experiments (Rutherford, Jena, MPQ)

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Numerical Tool
3D-PIC Code for Ideal Laser Matter Interaction
ILLUMINATION
x Laser Polarization
z Propagation direction
y
Laser Pulse
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5fs, a5, w05µm, ?p8µm

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5fs, a5
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5fs, a5, 70MeV e-
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5fs, a5, 60-80MeV e-
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5fs, a5, 60-80MeV e-
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5fs, a5, 60-80MeV e-
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5fs, w05µm, ?p8µm

a3 a5 a10 a30
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5fs Summary

a3 a5 a10 a30
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,peak 1.2x109 14mJ 3.8x109 75mJ 24x109 1300mJ
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5fs Scaling

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5fs, a5
with Gas denstity profile
Focus position
N0
z
200µm
200µm
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5fs, a5, ?p8µm, profile
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MPQ 5fs, a5, w02µm 20mJ
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RAL 40fs, a0.767, 390mJ
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RAL 40fs, a0.767, 390mJ
Ne 10201/cm³
Intensity 1019 W/cm²
z µm
z µm
Ez 1012V/m
z µm
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Jena 80fs, a3
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80fs, a3
Ne 10201/cm³
I 1019W/cm²
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Conclusions

• Few-cycle pulses are most efficent for bubble
  acceleration
• (longer pulses become few-cycle during
  propagation)
• Acceleration is limited due
• Rbw0a0.25 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?

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40fs, a3