ENHANCED RAMAN FORWARD SCATTERING

Recent experiments on laser wake-field acceleration have indicated a d ramatically enhanced value of the accelerating field created through t he process of the Raman forward scattering instability. However, the u se of the Raman forward scattering instability can be improved. If the initial growth of the instability is from noise, its evolution has pr oblems of reproducibility and is unpredictable in both time and space. We suggest the addition of a small amount of one of the scattered pro ducts to the laser pulse or plasma as a seed. This allows the instabil ity to grow from a known and controllable source, giving predictable a nd reproducible results. Additionally, simulations show that the final wake field and pulse modulation occur much faster and are cleaner wit h a seed than without. Seeding is especially important when we are ope rating in the low plasma density or low laser pulse intensity regime. We discuss methods to produce a seed and applications for the producti on of short laser pulses and electron bunches by this process.