Terawatt picosecond CO[sub 2] laser technology for high energy physics applications

Demonstration of ultra-high acceleration gradients in the SM LWFA experiments put a next objective for the laser accelerator development: to achieve a low-emittance monochromatic acceleration over extended interaction distances. The emerging picosecond terawatt (ps-TW) CO2 laser technology helps to meet this strategic goal. Among the considered example are: the staged electron laser accelerator (STELLA) experiment, which is being conducted at the Brookhaven ATF, and the plasma-channeled LWFA. The long-wavelength and high average power capabilities of CO2 lasers may be utilized also for generation of intense x-ray and gamma radiation through Compton back-scattering of the laser beams off relativistic electrons. We discuss applications of ps-TW CO2 lasers for a tentative γ-γ (or γ-lepton) collider and generation of polarized positron beams.