Excitation of Electromagnetic Flute Modes in the Process of Interaction of Plasma Flow with Inhomogeneous Magnetic Field

Abstract

Laboratory experiments on the interaction of a plasma flow, produced by laser ablation of a solid target with the inhomogeneous magnetic field from the Zebra pulsed power generator demonstrated the presence of strong wave activity in the region of the flow deceleration. The deceleration of the plasma flow can be interpreted as the appearance of a gravity-like force. The drift due to this force can lead to the excitation of flute modes. In this paper a linear dispersion equation for the excitation of electromagnetic flute-type modes with plasma and magnetic field parameters, corresponding to the ongoing experiments is examined. Results indicate that the wavelength of the excited flute modes strongly depends on the strength of the external magnetic field. For magnetic field strengths ∼0.1 MG the excited wavelengths are larger than the width of the laser ablated plasma plume and cannot be observed during the experiment. But for magnetic field strengths ∼1 MG the excited wavelengths are much smaller and can then be detected.

Investigation of flute instability in application to laboratory astrophysics and Z-pinch experiments

“…In the previous studies (Sotnikov et al 2006(Sotnikov et al , 2008 the area of applicability of the nonlinear set of equations was limited to values of kρ i < 1. A description of the experimental setup for laboratory astrophysics experiments can be found in Presura et al (2005) and Sotnikov et al (2007). A detailed description of Z-pinch experiments related to the excitation and nonlinear evolution of flute modes is presented in Ivanov et al (2007).…”