Bubble Acceleration with few-cycle pulses Max-Planck-Institut für Quantenoptik Bubble Acceleration with few-cycle pulses 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…)

Numerical Tool 3D-PIC Code for Ideal Laser Matter Interaction: ILLUMINATION x – Laser Polarization z – Propagation direction y Laser Pulse

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-

5fs, w0=5µm, p=8µm a=3 a=5 a=10 a=30

5fs Summary a=3 a=5 a=10 a=30 Epeak (80MeV) 80MeV 130MeV 310MeV Lmax 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

5fs Scaling

with Gas denstity profile: 5fs, a=5 with Gas denstity profile: Focus position N0 z 200µm 200µm

5fs, a=5, p=8µm, profile

MPQ: 5fs, a=5, w0=2µm; 20mJ

RAL: 40fs, a=0.767, 390mJ

RAL: 40fs, a=0.767, 390mJ Ne [10201/cm³] Intensity [1019 W/cm²] z [µm] Ez [1012V/m] z [µm]

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