Picosecond short-range disordering in isochorically heated aluminum at solid density

Area of Science:

• Materials Science
• Plasma Physics
• Condensed Matter Physics

Background:

• Understanding the behavior of materials under extreme conditions, such as high temperatures and densities, is crucial for various scientific and technological applications.
• Aluminum (Al) is a widely used metal, and its response to rapid heating is of significant interest.

Purpose of the Study:

• To experimentally investigate the progressive loss of ordering in solid-density aluminum as it is heated to extreme temperatures.
• To determine the timescale for the onset of ion lattice disorder in warm dense matter.

Main Methods:

• Isochoric heating of an aluminum sample using a picosecond (ps), laser-accelerated proton beam.
• Ultrafast x-ray probing utilizing a broadband x-ray source around the Al K edge.
• Time-resolved x-ray absorption near-edge spectroscopy (XANES) to monitor structural changes.

Main Results:

• Observed a progressive loss of ordering in solid-density aluminum as temperature increased from 300 K to over 10,000 K.
• Detected the loss of short-range ordering through the progressive smoothing of the time-resolved XANES structure.
• Established an upper bound of approximately 10 picoseconds for the onset of ion lattice disorder.

Conclusions:

• The experimental results provide valuable data for validating theoretical models of warm dense matter.
• The study demonstrates the capability of ultrafast x-ray probing to capture dynamic structural changes in materials under extreme conditions.