Field-based DGTD/PIC technique for general and stable simulation of interaction between light and electron bunches

Abstract

We introduce a hybrid technique based on the discontinuous Galerkin time domain (DGTD) and the particle in cell (PIC) simulation methods for the analysis of interaction between light and charged particles. The DGTD algorithm is a three-dimensional, dual-field and fully explicit method for efficiently solving Maxwell equations in the time domain on unstructured grids. On the other hand, the PIC algorithm is a versatile technique for the simulation of charged particles in an electromagnetic field. This paper introduces a novel strategy for combining both methods to solve for the electron motion and field distribution when an optical beam interacts with an electron bunch in a very general geometry. The developed software offers a complete and stable numerical solution of the problem for arbitrary charge and field distributions in the time domain on unstructured grids. For this purpose, an advanced search algorithm is developed for fast calculation of field data at charge points and for later importing to the PIC simulations. In addition, we propose a field-based coupling between the two methods resulting in a stable and precise time marching scheme for both fields and charged particle motion. To benchmark the solver, some examples are numerically solved and compared with analytical solutions. Eventually, the developed software is utilized to simulate the field emission from a flat metal plate and a silicon nano-tip. In the future, we will use this technique for the simulation and design of ultrafast compact x-ray sources.

Mapping Photoemission and Hot-Electron Emission from Plasmonic Nanoantennas

“…The results of the simulated optical near-field were used to estimate optical-field-driven photoemission currents from these plasmonic nanoantennas using a Fowler-Nordheim model for electron emission. 20,50,51 The trajectories of emitted electrons were additionally simulated using a particle-in-cell model to produce a map of the distribution of electrons colliding with the ITO substrate after emission from the plasmonic antenna. 51 Simulations of electron trajectories were performed in vacuum without the overlying PMMA layer In this work, we also used thin films of HSQ as imaging layers for electron emission and energy transfer from plasmonic nanorods.…”

Schrödinger electrons interacting with optical gratings: quantum mechanical study of the inverse Smith–Purcell effect

“…The reason that such quantum mechanical approaches have been not yet employed to study the inverse Smith-Purcell effect is mostly due to the very short de Broglie wavelength of electrons at high energies compared to optical wavelengths and dimensions of employed devices, and partly due to the lack of an equivalent and stable particle-in-cell numerical approach in quantum mechanics. In fact, self-consistent Maxwell-Lorentz simulations and particle-in-cell numerical approaches are routinely applied to study the interaction of electrons with electromagnetic waves in electron-driven photon sources and accelerators [46][47][48]. Here, a step towards the development of a self-consistent Maxwell-Schrödinger numerical tool-box is reported and exploited to investigate the inverse Smith-Purcell effect.…”

Short electron bunch generation using single-cycle ultrafast electron guns

“…All the bunch evolution calculations in this study are carried out with the consideration of space-charge effects which is simulated using a point-to-point algorithm. For more details on the implemented algorithm, the reader is referred to [29]. For initialization of macro-particles in the guns, we have used the ASTRA photoemission model [30,31].…”