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Description
We discuss the design and performance of a pulse-forming network (PFN)–based pulsed power
supply developed for whistler wave excitation in the Large Volume Plasma Device (LVPD-U).
The LVPD-U produces a quiescent argon plasma with a typical density of ~3 × 10¹⁷ m⁻³ and an
electron temperature of ~4–5 eV, immersed in an axial magnetic field of 6.2 G. The pulsed
power system is based on the discharge of a 50Ω characteristics impedance of PFN on a 50Ω
Loop Antenna, capable of storing up to 12 C at a maximum charging voltage of ≤ 20 kV for ≤
200A antenna current, through triggered switching of Hydrogen Thyratron. The PFN output is
coupled with an electrical galvanic isolation to the loop antenna inside the device through a wide
band ferrite-core transformer with inherent impedance matching. A novel current amplitude
clipping feature is ensured by playing with BH curve of the ferrite core transformer by raising
ferrite core magnetization through a feeble DC biasing loop to the transformer core. The
performance of the exciter system is characterized through the excitation of electromagnetic
hydrodynamic (EMHD) structures in LVPD plasma and the pulse has been detected by a 3-axis
magnet probe. The system provides a controlled and flexible experimental platform for
laboratory investigations of whistler wave dynamics, magnetic reconnection, and related space
plasma phenomena. Additionally, several experimentally observed features of physical relevance
are discussed with results from LVPD experiments.