Quantum plasma simulation with a Bohmian smoothed particle hydrodynamic framework

Thesis

A novel approach to the modelling of quantum plasmas on the electronic timescale is presented in this work, Bohm SPH. The primary purpose of Bohm SPH is to investigate the structural and dynamical properties of warm dense matter, encountered in inertial confinement fusion implosions and certain astrophysical environments. With strong ionic coupling and quantum mechanical electrons, the simulation of warm dense matter presents a formidable challenge. Moving beyond the Born-Oppenheimer approxima- tion applied by the widely used DFT-MD, electron dynamics are included explicitly in Bohm SPH. This is done without enormous computational expense and in a highly parallelisable code structure, enabling the investigation of large warm dense matter systems over ionic timescales at electronic time resolution. Given the novelty of the model and the approximations applied, particularly the use of a smoothed particle hy- drodynamic scheme to resolve the electron density and a quantum hydrodynamic Bohm pressure, much of the work involves describing its construction, implementation, and modular validation. In two subsequent chapters, Bohm SPH is tasked with calculating the dynamic structure properties of warm dense hydrogen and the relaxation of non- thermal electrons in an XFEL-generated aluminium plasma, where it has success when the degrees of freedom of the model are properly considered.

Authors: Campbell, TIF

• DOI: 10.5287/ora-xoj1p7akz
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: warm dense matter; inertial confinement fusion; quantum mechanics; plasma physics; smoothed particle hydrodynamics; Bohm potential
• Subjects: Physics