Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime

Abstract

The extraordinary ability of space-charge waves in plasmas to accelerate charged particles at gradients that are orders of magnitude greater than in current accelerators has been well documented. We develop a phenomenological framework for laser wakefield acceleration (LWFA) in the 3D nonlinear regime, in which the plasma electrons are expelled by the radiation pressure of a short pulse laser, leading to nearly complete blowout. Our theory provides a recipe for designing a LWFA for given laser and plasma parameters and estimates the number and the energy of the accelerated electrons whether self-injected or externally injected. These formulas apply for self-guided as well as externally guided pulses (e.g. by plasma channels). We demonstrate our results by presenting a sample particle-in-cell (PIC) simulation of a 30 fs, 200 TW laser interacting with a 0.75 cm long plasma with density 1:5 10 18 cm ÿ3 to produce an ultrashort (10 fs) monoenergetic bunch of self-injected electrons at 1.5 GeV with 0.3 nC of charge. For future higher-energy accelerator applications, we propose a parameter space, which is distinct from that described by Gordienko and Pukhov [Phys. Plasmas 12, 043109 (2005)] in that it involves lower plasma densities and wider spot sizes while keeping the intensity relatively constant. We find that this helps increase the output electron beam energy while keeping the efficiency high.

Polarized beam conditioning in plasma based acceleration

“…These analytical results can still be applied to unmatched regimes in the PWFA or in configurations associated with the external injection of electrons in plasma wakes. In fact, the beam energy, energy spread, emittance, transverse spot size, and number of accelerated electrons can only be effectively controlled when electrons are externally injected at the rear of the plasma wave [9,26]. In this case it is advantageous to reduce the beam emittance to be as small as possible, thereby increasing the luminosity of the bunches, entering in a regime where Eq.…”

“…These results were obtained in the blowout regime, where plasma electrons are evacuated from the region where the driver propagates. The resulting wakefield structures are characterized by linear accelerating and focusing forces, and are ideally suited for electron acceleration [8][9][10].…”

Generalized algorithm for control of numerical dispersion in explicit time-domain electromagnetic simulations

“…The PIC algorithm uses FDTD to update the electromagnetic fields, while tracking particles in continuous phase space. PIC simulations were used to predict injection of quasimonoenergetic bunches in self-trapping LPA experiments [26], and continue to be used extensively to understand the complex dynamics of the injection process [27][28][29][30].…”

Bright spatially coherent synchrotron X-rays from a table-top source

“…As there are consecutive phases of injection, the electron beam consists of multiple beamlets, which could be seen in both profile and spectral measurements 14 We typically measure 100-300 pC of charge in the beam. The average and maximum energy of the electron beam follow the typical wakefield electron density scaling law 14,18 .…”