Submicrosecond Spectroscopy of Lightning-Like Discharges: Exploring New Time Regimes

Area of Science:

• Plasma Physics
• Spectroscopy
• Electrical Engineering

Background:

• Understanding electrical discharges is crucial for atmospheric science and engineering.
• Previous spectral analysis of electrical discharges lacked the temporal resolution to capture rapid dynamic changes.

Purpose of the Study:

• To record and analyze the time-resolved spectra of laboratory-produced lightning-like electrical discharges with submicrosecond resolution.
• To investigate the spectral time dynamics, electron density, and gas temperature of these discharges.

Main Methods:

• Utilized the GrAnada LIghtning Ultrafast Spectrograph (GALIUS) for high-resolution spectral recording.
• Generated meter-long electrical discharges using a 2.0 MV Marx generator.
• Analyzed spectra in the visible range (645-665 nm) with submicrosecond temporal resolution (0.476 μs/frame).

Main Results:

• Achieved the first submicrosecond time-resolved spectra of laboratory electrical discharges.
• Measured maximum electron density of approximately 10^18 cm^-3 and gas temperature of 32,000 K within 0.50 μs.
• Explored spectral time dynamics, overpressure, black-body radiation, and self-absorption phenomena.

Conclusions:

• The study provides unprecedented insights into the rapid evolution of lightning-like plasmas.
• The GALIUS instrument enables high-fidelity spectral analysis of transient high-energy events.
• Findings contribute to a deeper understanding of electrical discharge physics and atmospheric phenomena.