Enhanced betatron radiation by off-axis laser injection in a capillary plasma source

Summary form only given. Generation of high-energy betatron X-rays is very important and attractive for many applications. In this presentation, we propose a new method for generating shorter wavelength X-rays in a capillary plasma waveguide, which has a parabolic density profile in the transverse direction. In this method, we inject an intense laser pulse at an off-axis position in the capillary plasma waveguide, and the ion cavity follows the wiggling laser trajectory in the plasma waveguide. This kind of ion cavity motion can increase the oscillation amplitude of the electrons in the wakefield acceleration process. As a result, shorter wavelength betatron radiations can be produced in this scheme. We have performed two-dimensional (2-D) particle-in-cell (PIC) simulations¹ and analytical studies for this research. We show some results of the ongoing research activities in this presentation.