Prospects for laser wakefield accelerators and colliders using CO2 laser drivers

Energy directly acquired by an electron from the laser electromagnetic field is quadratically proportional to the laser wavelength. Exploiting this feature, the emerging terawatt picosecond (TWps) CO2 lasers, having an order of magnitude longer wavelength than the well-known table-top terawatt (T3) picosecond solid state lasers, offer new opportunities for strong-field physics research. Laser accelerators serve as an example where application of the new class of lasers will result in enhancement in gas ionization, plasma wave excitation, and relativistic self-focusing. Ponderomotively strong CO2 laser permits a 100 times reduction in the plasma density without impeding the acceleration. The improved performance of the low-pressure laser wakefield accelerators (LWFA) is potentially due to higher electric charge per accelerated bunch and better monochromaticity. The multi-kilowatt average power, high repetition rate capability of the TWps-CO2 laser technology opens new opportunities in development of compact, ∼1 m long, GeV accelerators and <1 km long high-luminosity multi-stage LWFA colliders of the TeV scale. The first TWps-CO2 laser is under construction at the BNL Accelerator Test Facility (ATF).