Next generation accelerators and colliders using relativistic electron beams are continuously pushing the demand for higher luminosity beams with smaller and smaller spot sizes. To address this need, passive plasma lenses operating in the nonlinear blowout regime of beam-driven plasma wakefield acceleration (PWFA) are capable of providing focusing forces to electron beams orders of magnitude stronger than conventional quadrupole magnets. To realize these lenses in practice, high intensity lasers can be used to ionize a small volume of gas and producing a plasma lens with precisely determined density profile.
The quality of an electron beam focused by a plasma lens is determined by the phase space evolution of the beam while it is within the plasma wakefield. The strong electric fields can also increase an electron beam's emittance through chromatic phase spreading, which deteriorates the transverse quality of the beam. This dissertation covers the formalism used to describe the focusing of an electron beam from a passive, underdense plasma lens and demonstrates use cases for these lenses in experiments using relativistic electron beams.
To perform plasma lens experiments, we propose a setup to ionize a 100 µm scale plasma lens via laser ionization of a gas jet outflow at the FACET-II accelerator facility of SLAC National Accelerator Laboratory. We investigate possible focusing aberrations induced by nonuniform transverse density profiles. Finally, we report on experimental progress towards the demonstration of an underdense thin plasma lens, including the analysis of preliminary data from commissioning shifts carried out at FACET-II.</p
