Self-diffusion of a relativistic Lennard-Jones gas via semirelativistic molecular dynamics

Physical Review E American Physical Society 107:5 (2023) 054138

Authors:

David Miles Testa, Pontus Svensson, Jacob Jackson, Thomas Campbell, Gianluca Gregori

Abstract:

The capability for molecular dynamics simulations to treat relativistic dynamics is extended by the inclusion of relativistic kinetic energy. In particular, relativistic corrections to the diffusion coefficient are considered for an argon gas modeled with a Lennard-Jones interaction. Forces are transmitted instantaneously without being retarded, an approximation that is allowed due to the short-range nature of the Lennard-Jones interaction. At a mass density of 1.4g/cm3, significant deviations from classical results are observed at temperatures above kBT≈0.05mc2, corresponding to an average thermal velocity of 32% of the speed of light. For temperatures approaching kBT≈mc2, the semirelativistic simulations agree with analytical results for hard spheres, which is seen to be a good approximation as far as diffusion effects are concerned.

Demonstration of tunability of HOFI waveguides via start-to-end simulations

(2023)

Authors:

SM Mewes, GJ Boyle, A Ferran Pousa, RJ Shalloo, J Osterhoff, C Arran, L Corner, R Walczak, SM Hooker, M Thévenet

Model Independent Electron-Ion Equilibration Rate, Debye Temperature, and Bond Strength Measurements in Warm Dense Metals with Inelastic X-Ray Scattering

Institute of Electrical and Electronics Engineers (IEEE) 00 (2023) 1-1

Authors:

TD Griffin, D Haden, T White, B Nagler, H-J Lee, E Galtier, D Khaghani, S Yunus, E Cunningham, J Hastings, J Molina, S Glenzer, E McBride, L Fletcher, G Monaco, U Zastrau, K Appel, S Goede, L Wollenweber, D Gericke, G Gregori, A Descamps, B Armentrout, M Convery, S Goede

Radiative Instabilities in the Stagnation Layer of Colliding, X-Ray Driven Plasma Flows

Institute of Electrical and Electronics Engineers (IEEE) 00 (2023) 1-1

Authors:

K Marrow, T Mundy, J Halliday, A Crilly, J Chittenden, R Mancini, S Merlini, S Rose, D Russell, J Strucka, L Suttle, V Valenzuela-Villaseca, S Bland, S Lebedev

Monte Carlo modeling of the linear Breit-Wheeler process within the geant4 framework

Physical Review Accelerators and Beams American Physical Society 26:5 (2023) 54601

Authors:

Ra Watt, Sj Rose, B Kettle, Spd Mangles

Abstract:

A linear Breit-Wheeler module for the code geant4 has been developed. This allows signal-to-noise ratio calculations of linear Breit-Wheeler detection experiments to be performed within a single framework. The interaction between two photon sources is modeled by treating one as a static field, then photons from the second source are sampled and tracked through the field. To increase the efficiency of the module, we have used a Gaussian process regression, which can lead to an increase in the calculation rate by a factor of up to 1000. To demonstrate the capabilities of this module, we use it to perform a parameter scan, modeling an experiment based on that recently reported by Kettle et al. [New J. Phys. 23, 115006 (2021)]. We show that colliding 50-fs duration γ rays, produced through bremsstrahlung emission of a 100 pC, 2-GeV laser wakefield accelerator beam, with a 50-ps x-ray field, generated by a germanium burn-through foil heated to temperatures > 150 eV, this experiment is capable of producing > 1 Breit-Wheeler pair per shot.