Sep 18 – 24, 2022
Hotel Hermitage, La Biodola Bay, Isola d'Elba, Italy
Europe/Rome timezone

Multitask optimization of laser-plasma accelerators using simulation codes with different fidelities

Sep 21, 2022, 7:15 PM
Sala Elena - Hotel Hermitage

Sala Elena - Hotel Hermitage


Angel Ferran Pousa


Laser-plasma accelerators can generate GeV electron beams in an ultra-compact, cm-scale setup, but have yet to demonstrate sufficient beam quality and stability for demanding applications. To overcome this challenge, broad optimization of the accelerator design with numerical simulations is essential. However, due to the high computational cost of general particle-in-cell simulations, optimization over a large parameter space is prohibitively expensive. Here, we show that cheaper simulations based on reduced physical models can be effectively incorporated into an optimization to strongly reduce the need for fully-detailed simulations. This is enabled by a Bayesian optimization algorithm using a multitask Gaussian process, where two tasks corresponding to the output of each simulation code are defined. The algorithm identifies correlations between both tasks, allowing it to learn from inexpensive evaluations and perform only a few, well-targeted simulations of high fidelity. By means of a proof-of-principle study combining the FBPIC and Wake-T codes, we demonstrate an order-of-magnitude reduction in computing time and cost, paving the way towards cost-effective optimization over wide parameter spaces.

Primary authors

Angel Ferran Pousa Sören Jalas Manuel Kirchen Alberto Martinez de la Ossa (DESY) Maxence Thevenet (DESY) Dr Stephen Hudson (Argonne National Laboratory) Dr Jeffrey Larson (Argonne National Laboratory) Dr Axel Huebl (Lawrence Berkeley National Laboratory) Jean-Luc Vay (Berkeley Lab) Remi Lehe (Lawrence Berkeley National Laboratory)

Presentation materials