The free‐decaying two‐dimensional (2D) turbulence in a pure electron plasma confined in the Malmberg‐Penning trap ELTRAP is investigated experimentally and analyzed through the Proper Orthogonal Decomposition (POD). POD is used to extract coherent structures of the flow from a sequence of plasma density measurements, which represent the vorticity of the 2D fluid. The coherent structures that are energetically dominant are identified and their spatio‐temporal dynamics is studied over the time evolution of turbulence. The results suggests the the dominant POD modes can be identified with diocotron modes which appear to be active during both the onset and relaxation phases of turbulence.
Proper Orthogonal Decomposition of Two-Dimensional Turbulence in a Pure Electron Plasma
LEPRETI, Fabio;CARBONE, Vincenzo;VALENTINI, Francesco
2010-01-01
Abstract
The free‐decaying two‐dimensional (2D) turbulence in a pure electron plasma confined in the Malmberg‐Penning trap ELTRAP is investigated experimentally and analyzed through the Proper Orthogonal Decomposition (POD). POD is used to extract coherent structures of the flow from a sequence of plasma density measurements, which represent the vorticity of the 2D fluid. The coherent structures that are energetically dominant are identified and their spatio‐temporal dynamics is studied over the time evolution of turbulence. The results suggests the the dominant POD modes can be identified with diocotron modes which appear to be active during both the onset and relaxation phases of turbulence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
