Figure 5
From: Stable femtosecond X-rays with tunable polarization from a laser-driven accelerator
Simulation of the effect of a small laser energy change on the electron beam profile. (a, b) show the electron distribution after acceleration in pure helium; (c, d) show that in a mixture of 99% helium and 1% nitrogen. Left figures are for a0=2.0; right figures are for a0=1.95. A slight variation of laser intensity drastically changes the electron beam profile for transverse injection, while it remains unchanged for ionization injection. The laser is linearly polarized along the y axis (yellow line).
