An ultrasound probe array for a high-pressure, high-temperature solid medium deformation apparatus.

Area of Science:

• Geophysics
• Materials Science
• Experimental Petrology

Background:

• Inelastic deformation in rocks and minerals involves defects like fractures, twins, and dislocations.
• Ultrasound probes offer a method to study these defects under various pressure and temperature conditions.

Purpose of the Study:

• To develop and characterize an ultrasound probe array for monitoring deforming samples in a high-pressure, high-temperature apparatus.
• To enable real-time acoustic emission analysis during rock deformation experiments.

Main Methods:

• Utilized broadband miniature piezoelectric sensors above and below the sample for acoustic emission detection.
• Implemented high sampling rates (50 MS/s) and resolution (12 bit) for precise data acquisition.
• Engineered robust grounding, insulation, and power delivery to minimize electromagnetic interference.

Main Results:

• Achieved a low background noise level (≈90 mV) with significant amplification (60 dB).
• The system successfully recorded acoustic waves across a broad frequency range (80 kHz to 2.5 MHz).
• Demonstrated capability to operate at temperatures up to 1100 °C and pressures up to 2.5 GPa.

Conclusions:

• The developed ultrasound probe array is effective for monitoring inelastic deformation and associated acoustic emissions in minerals and rocks.
• This technology facilitates the investigation of defect activation under simulated geological conditions.
• The system provides a valuable tool for understanding rock mechanics and material behavior at extreme conditions.