ASP Online Seminars: From Nanometers to Magnetospheres: A Scale-Invariant View of Plasma Dynamics

by Prof. Waleed Moslem (Port Said University & The British University, Egypt)

Tuesday 21 Apr 2026, 13:00 → 14:30 UTC

Abstract:

Plasmas generally look fully different at very different scales, but many of their most important dynamical behaviors are determined by exactly the same basic physics. Here, I discuss how a scale-free, self-similar description of plasma expansion governs several seemingly diverse plasmas: from nanometer-scale surface plasmas to planetary ion outflows. When a plasma is produced by laser–matter interaction, its subsequent expansion can be described within a self-similar multispecies fluid framework, in which ambipolar electrostatic fields drive density rarefaction, ion acceleration, and the emergence of a leading front across regimes that differ greatly in scale. For expansion at the nanoscale, this unified view enables understanding of expansion-driven surface nanopit formation. For multispecies expanding space plasma, this framework provides an explanation of the role of ions escaping in the Martian and Venusian upper ionosphere. These results together support the idea that self-similarity offers not simply a mathematical convenience but a powerful physical connection between laboratory and planetary plasmas.

 

Bio of the speaker:

Professor Waleed Moslem is a theoretical plasma physicist at Port Said University and is currently serving as a visiting professor at the British University in Egypt. He earned his PhD in 2002 from Mansoura University and subsequently received a prestigious fellowship from the Alexander von Humboldt Foundation, conducting research at Ruhr University Bochum, Germany. Professor Moslem has published more than 190 refereed articles in highly ranked journals covering the dynamics of classical, dusty, and quantum plasmas, the modeling of nanostructure formation using ion beam technology, and plasma waves and ion escape processes in planetary environments. He has an h-index of 41 and over 5,000 citations in Web of Science and Scopus. Professor Moslem was an editorial board member in Physica Scripta (2022-2026). He has been a dedicated peer reviewer for over 50 renowned international journals and has supervised more than 50 M.Sc. and PhD theses. Professor Moslem founded the EGYPlasma Society in 2016, which is the first plasma physics society in the Arab world.

 

ASP-Seminar-April2026.mp4

ASP-Seminar-April2026-Prof_Moslem.pdf