WEYBA4
Stony Brook University, Stony Brook, USA
Particle-driven Plasma Wakefield Accelerators (PWFAs) are promising candidates for future free electron laser and collider applications. In PWFAs, energy is transferred from a relativistic drive beam to a trailing bunch in a plasma wake. One of the challenges of PWFAs is reducing energy spread of the beam from typically few percent to the required 0.1% range. This can be accomplished by generating a trailing bunch with a trapezoidal density profile, which will allow the PWFA to operate in the beam-loading regime, therefore circumventing the energy-spread growth of the trailing beam during acceleration. In this work we show how the Beam Induced Ionization Injection (BIII) technique can produce a trailing bunch of electrons with a trapezoidal shape suitable for beam-loading. In BIII, the trailing beam is created by ionization injection of an impurity due to the increased field of the beam during betatron oscillations. By tailoring the longitudinal profile of the impurity, we can shape the injected trailing electron bunch to reach the beam-loading regime. We will present results of numerical simulations done to model BIII shaped beams with the Particle In Cell code OSIRIS*.
* R. A. Fonseca et al., Lect. Notes Comput. Sci. 2331, 342 (2002).
Stony Brook University, Stony Brook, USA
BNL, Upton, New York, USA
The University of Texas at Austin, Austin, Texas, USA
UCLA, Los Angeles, California, USA
SBU, Stony Brook, USA
Laser-driven plasma wakefield acceleration (LWFA) is considered as a potential technology for future colliders and light sources. To make the best use of a laser’s power, the laser is expected to maintain a stable propagation. A transverse instability is observed in our previous simulations when a long, intense CO2 laser propagates inside a plasma*. This unstable motion is accompanied by strong transverse diffraction of the laser power and results in the disruption of the ion channel typically used for radiation generation**. We investigated the hosing-like instability using the Particle-in-Cell code OSIRIS*** by modeling the laser portion where this instability is seeded and then evolves. In this proceeding, a criteria will be described that allows for the characterization of the temporal and spatial evolution of this instability.
*J. Yan, et al. , AAC, IEEE, 2018.
** L. Nemos et al., PPCF, 58(3), 2016.
***R. A. Fonseca et al., Lecture Notes Computation Science (2331) 342, 2002.