Determining velocity of detonation using high-resolution time domain reflectometry

Area of Science:

• Electrical Engineering
• Physics
• Materials Science

Background:

• Accurate measurement of coaxial cable length is crucial for various applications, including high-speed electronics and detonation physics.
• Existing methods may lack precision or be unsuitable for scenarios involving cable destruction.

Purpose of the Study:

• To present two new methods for measuring coaxial cable length with submillimeter and submicrosecond accuracy.
• To enable accurate measurement of the velocity of detonation (VOD) in cables, even when destroyed by shock waves.

Main Methods:

• Method 1: Utilizes short Gaussian electrical pulses reflected off the cable end, analyzed with a fast digitizer and curve fitting for sub-sample length accuracy.
• Method 2: Employs a wide-spectrum amplified random noise source, with reflected waveforms autocorrelated to determine transit time and cable length.

Main Results:

• Both methods achieve submillimeter and submicrosecond accuracy in cable length measurements.
• Accurate velocity of detonation (VOD) measurements (≈0.25%) are obtainable, comparable to traditional techniques.
• The random noise method allows for more extensive averaging of length estimates, enhancing VOD measurement precision.

Conclusions:

• The presented Gaussian pulse and random noise methods provide accurate and reliable means for coaxial cable length and VOD determination.
• These techniques are particularly valuable for dynamic measurements in destructive environments.
• Detailed implementation and data analysis are provided, outlining the capabilities and limitations of each method.