A very powerful laser can be used to accelerate electrons to high energies by interacting with a state of matter known as a plasma, an ionized gas of charged particles. The laser achieves this by creating waves in the plasma, like a boat pushing through water, on which the electrons can surf and be accelerated to high energies. In this specific project the pulse of laser light will be controlled and the structure of these waves mapped out in time and space, both with unprecedented precision. These techniques should help the development of compact particle accelerators. Accelerators represent a $3B per year market, but their overall impact is even greater since they find use in everything from cancer therapy to imaging stresses in aircraft wings. Thus, the development of compact and cheap accelerators is likely to have a significant impact both economically and technologically.
The research project will use the high repetition rate of the relativistic intensity (~10^19 W per square cm, 35 fs) laser, "Lambda-cubed", located on campus at the University of Michigan - Ann Arbor to enable unique measurements of laser propagation and wakefield formation, to exert unprecedented control of laser wakefield acceleration, and to generate up to 10 MeV, few fs duration electron beams at 0.5 kHz. Stable, high quality relativistic electron beams at up to 10 MeV at 0.5 kHz repetition rate using the Lambda-cubed laser will be generated by making use of advances in pulse compression and feedback control made at the University of Michigan. A 5 fs pulse will be used as an ultrafast 4D probe of the plasma wakefield structure, allowing unique tomographic characterization of the accelerator structure.