Dynamics of vapor emissions at wire explosion threshold

Area of Science:

• Plasma physics
• Materials science
• Fluid dynamics

Background:

• X-pinch plasmas are of recent research interest.
• Numerical simulations indicate metallic wires reach a supercritical state before explosion under Ohmic heating.
• Heating rates are sensitive to wire resistance, causing variable vapor emission flux.

Purpose of the Study:

• To visualize nickel wire explosions using shock wave formation in air.
• To characterize the dynamics of shock fronts and vapor plume temperature.

Main Methods:

• Utilized shadowgraphy to capture nickel wire explosions.
• Analyzed shock wave formation with spherical and cylindrical wave fronts.
• Employed continuum emission spectra for temperature measurements near the explosion threshold.

Main Results:

• Observed multiple shock waves originating from different wire sections during explosions.
• Characterized shock front growth using power-law scaling.
• Measured temperatures near the explosion threshold and examined shock front structures and vapor plume characteristics.

Conclusions:

• Nickel wire explosions generate complex shock structures and exhibit power-law scaling in shock front dynamics.
• Temperature measurements provide insights into the conditions near the explosion threshold.
• The study enhances understanding of vapor emission processes in exploding wires.