Tuning curves for a laser-plasma accelerator

Jalas, Sören; Kirchen, Manuel; Braun, C.; Eichner, Timo; Gonzalez, J. B.; Hübner, Lars; Hülsenbusch, Thomas; Messner, Philipp; Palmer, Guido; Schnepp, M.; Werle, Christian; Winkler, Paul; Leemans, Wim; Maier, Andreas R.

doi:10.1103/physrevaccelbeams.26.071302

Cited by 5 publications

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the evolutionary algorithms are nearly impossible to use for online accelerator tunings 23 . To this end, the Multi-Objective Bayesian Optimization (MOBO) scheme 20 , 29 was recently introduced. This method uses a set of GP surrogate models, along with a multi-objective HyperVolume (HV) improvement acquisition function, to reduce the number of observations needed.…”

Section: Introductionmentioning

confidence: 99%

Multi-objective Bayesian active learning for MeV-ultrafast electron diffraction

Ji,

Edelen,

Roussel

et al. 2024

Nat Commun

View full text Add to dashboard Cite

Ultrafast electron diffraction using MeV energy beams(MeV-UED) has enabled unprecedented scientific opportunities in the study of ultrafast structural dynamics in a variety of gas, liquid and solid state systems. Broad scientific applications usually pose different requirements for electron probe properties. Due to the complex, nonlinear and correlated nature of accelerator systems, electron beam property optimization is a time-taking process and often relies on extensive hand-tuning by experienced human operators. Algorithm based efficient online tuning strategies are highly desired. Here, we demonstrate multi-objective Bayesian active learning for speeding up online beam tuning at the SLAC MeV-UED facility. The multi-objective Bayesian optimization algorithm was used for efficiently searching the parameter space and mapping out the Pareto Fronts which give the trade-offs between key beam properties. Such scheme enables an unprecedented overview of the global behavior of the experimental system and takes a significantly smaller number of measurements compared with traditional methods such as a grid scan. This methodology can be applied in other experimental scenarios that require simultaneously optimizing multiple objectives by explorations in high dimensional, nonlinear and correlated systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Multi-objective Bayesian active learning for MeV-ultrafast electron diffraction

Ji,

Edelen,

Roussel

et al. 2024

Nat Commun

View full text Add to dashboard Cite

show abstract

“…Current LWFA research focuses mostly on improving the electron beam quality and operating LWFA's at higher repetition rates. One key aspect is in better reproducibility and control of important properties such as beam charge, energy, and pointing stability [18][19][20] or improving the beam quality (e.g. the beam emittance or energy spread) [21][22][23]; often by employing machine learning techniques and automation [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Laser polarization control of ionization-injected electron beams and x-ray radiation in laser wakefield accelerators

Mukherjee,

Seipt

2024

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

In this paper we have studied the influence of the laser polarization on the dynamics of the ionization-injected electron beams and subsequently the properties of the emitted betatron radiation in laser wakefield accelerators (LWFAs). While ionizing by a strong field laser radiation, generated photo-electrons carry a residual transverse momentum in excess of the ionization potential via the above threshold ionization process. This above threshold ionization (ATI) momentum explicitly depends on the polarization state of the ionizing laser and eventually governs the dynamics of the electron beam trapped inside the wake potential. In order to systematically investigate the effect of the laser polarization, here, we have employed complete three-dimensional (3-D) Particle-in-Cell (PIC) simulations in the nonlinear bubble regime of the LWFAs. We focus, in particular, on the effects the laser polarization has on the ionization injection mechanism, and how these features affect the final beam properties, such as beam charge, energy, energy spread, and transverse emittance. We have also found that as the laser polarization gradually changes from linear to circular, the helicityof the electron trajectory, and hence the angular momentum carried by the beam increases significantly. Studies have been further extended to reveal the effect of laser polarization on the radiation emitted by the accelerated electrons. The far-field radiation spectra have been calculated for the linear (LP) and circular polarization (CP) states of the laser. It has been shown that the spatial distributions and the polarization properties (Stokes parameters) of the emitted radiation in the above two cases are substantially different. Therefore, our study provides a facile and efficient alternative to regulate the properties of the accelerated electron beams and x-ray radiation in LWFAs, utilizing ionization injection mechanism.

show abstract

Beam physics studies for a high charge and high beam quality laser-plasma accelerator

Marini,

Minenna,

Massimo

et al. 2024

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

Electron acceleration by laser-plasma techniques is approaching maturity and is getting ready for the construction of particle accelerators with dedicated applications. We present a general methodology showing how beam physics studies can be used to achieve a specific parameter set in a laser-plasma accelerator. Laser systems, plasma targets, and magnetic component properties are designed to optimize the electron beam so as to achieve the required performances. Beam physics in its full 6D phase space is studied from electron injection to beam delivery to the end user, through the plasma acceleration stage and transport line. As each beam parameter can only be modified by specific electric/magnetic field configurations, it is crucial to assign from the beginning specific roles to given accelerator sections in obtaining given beam parameters. These beam physics considerations were successfully applied to the design of a plasma-based electron injector for the AWAKE Run2 experiment. Electron beam parameters were calculated using a global simulation, achieving simultaneously unprecedented high charge (100 pC) and high quality (micrometric beam emittance and size). Published by the American Physical Society 2024

show abstract

Tuning curves for a laser-plasma accelerator

Cited by 5 publications

References 27 publications

Multi-objective Bayesian active learning for MeV-ultrafast electron diffraction

Multi-objective Bayesian active learning for MeV-ultrafast electron diffraction

Laser polarization control of ionization-injected electron beams and x-ray radiation in laser wakefield accelerators

Beam physics studies for a high charge and high beam quality laser-plasma accelerator

Contact Info

Product

Resources

About