Speaker
Description
Particle-in-cell (PIC) simulations are a well-established tool to study and predict the outcomes of a Laser Plasma Accelerator experiment, but the results are often hindered by the initialization of highly idealized laser profiles. In this work, we present the development of a Laser Pulse reconstructor For Particle In Cell simulations (LP4PIC), a Python package to retrieve experimental laser fields to be initialized in a FBPIC simulation.
The retrieval of fields from fluence measurements is based on an improved Gerchberg-Saxton algorithm (GSa), taking in input a measurement before the focusing element and a series of focal scan measurements to retrieve the aberration phase.
LP4PIC is also provided with functions to simulate the focusing of any input profile through phase/absorption plates, eventually providing aberration coefficients, and to give an estimation of aberration coefficients, corresponding for instance to the GSa retrieved phase, performing a Zernike transform. The search for the aberration coefficients it is furtherly improved by a genetic algorithm which optimizes the coefficients obtained through the Zernike transform.
The so-rebuilt fields are finally initialized in a FBPIC simulation through a proper custom interface. Features and characteristics of LP4PIC will be shown through examples, also in terms of PIC simulations results.