That is also true, basically target imperfections plus noise in the laser cause imperfection in the acceleration process. Essentially the shape of the bubble ca

That is also true, basically target imperfections plus noise in the laser cause imperfection in the acceleration process. Essentially the shape of the bubble can change the accelerating fields uniformity, leading to the divergence and spread issues. They usually cryo their target to minimize just plain chaotic behavior from it being a gas, so generally most of the jitter is due to wings of the laser itself causing perturbations in the gas/plasma (it's a plasma once the peak reaches it). That said, you're totally right about the target itself being a source of noise too.