Density sensitivity study of density ramp injected electrons in laser wakefield accelerators
Laser wakefield accelerators are promising candidates for compact sources of relativistic electron beams and have the potential to revolutionise high-energy radiation sources by reducing their scale by many orders of magnitude. However, the stable accelerator performance required for applications is difficult to achieve due to the sensitivity of the injection and acceleration dynamics to initial conditions. A key parameter in the interaction is the plasma density, often taken as a constant and controlled by the pressure of the gas target. By tailoring the density profile, such as introducing a sharp longitudinal density transition in the target, it may be possible to improve the shot-to-shot stability of the accelerator. This talk presents experimental results of the electron beams generated in a tailored target and the shot-to-shot variations in the plasma density profile for nominally equal conditions. Through an in-depth sensitivity study using particle-in-cell simulations, the effects of fluctuations in the plasma density profile are investigated.