Seeding of the forward Raman instability by ionization fronts and Raman backscatter

The self-modulated laser wakefield accelerator utilizes the forward Raman instability to drive a large-amplitude plasma wave. The effectiveness of this process could depend on how it competes with other processes such as self-focusing and cavitation, or other instabilities such as filamentation and hosing. The relative timing between the various processes is dependent on the nature of the seed for each instability. Both ionization fronts and Raman backscatter are capable of seeding the forward Raman instability. This causes the forward Raman instability to emerge much earlier than would otherwise be expected.