The optimization and advanced study of a laser-plasma electron injector are presented based on a truncated ionization injection scheme for high quality beam production. The smilei code is used with laser envelope approximation and a low number of particles per cell to reach computation time performances enabling the production of a large number of accelerator configurations. The developed and tested workflow is a possible approach for the production of a large dataset for laser-plasma accelerator optimization. A selection of functions of merit used to grade generated electron beams is discussed. Among the significant number of configurations, two specific working points are presented in detail. All data generated are left open to the scientific community for further study and optimization.

The stability and the quality of particle beams are of utmost importance for many emerging linac installations. The impact on beam properties damage of beam electromagnetic element misalignments and jitter/fluctuations in various accelerator sub-systems should be properly known, as usually such shot-to-shot fluctuations cannot be avoided. On top of that, knowing which parameters the machine is most sensitive to is of utmost to take precautionary measures to reduce the beam degradation and thus improve beam stability and quality. This simulation work focuses on a 50 MeV S-band linear accelerator based on RF photoinjector electron source. The sensitivity of the beam parameters towards several errors has been studied collectively as well as individually for each accelerator element. While the emittance at the end of the linac is dominated by the laminar behavior in the accelerating section, the main emittance degradation comes mainly from orbit errors located at the linac entrance.

We present numerical simulations results on the injection and acceleration of a 10 MeV, 10 pC electrons beam in a plasma wave generated in a gas cell by a 2J, 45 fs laser beam. This modeling is related to the ESCULAP project in which the electrons accelerated by the PHIL photo-injector is injected in a gas cell irradiated by the laser beam of the LASERIX system. Extensive modeling of the experiment was performed in order to determine optimal parameters of the laser plasma configurations. This was done with the newly developed numerical code WakeTraj . We propose a configuration that benefits of a highly compressed electron bunch and for which the injected electron beam can be efficiently coupled to the plasma wave and accelerated up to 140 MeV, with an energy spread lower than 5%.

The present article reports on the generation of stable 50 pC low-divergence electron beams above 150 MeV from laser-driven wakefield acceleration using a continuous-flow gas target prototype tested at the 60 TW Salle Jaune facility at LOA. The gas target design is meant to be easily transported and integrated as an element of the beamline with a differential pumping system offering some 10⁻⁴ mbar pressure in the rest of the line. A dedicated gas injection system allows for the control of the gas mixture concentration and gas pressure in two different regions of the target within the frame of controlled ionisation injection schemes. The measured electron beam parameters show the importance of gas density profiles and longitudinal gas mixture confinement.