The Compact Pulsed Power Facility at the Institute for Shock Physics at Washington State University is one of only two such facilities currently operating in the United States. The CPPF system is based on technology developed at Sandia National Laboratories (Z Accelerator), and offers a unique, extremely versatile, and fast approach for characterizing and evaluating dynamic materials response for diverse applications.

Using shockless, high-pressure loading, Applied Sciences Laboratory researchers using CPPF resources and technology can determine sample response and obtain data in a single experiment—in significant contrast to traditional methods of running multiple experiments. Additionally, the dynamic responses of two to four materials can be obtained in a single experiment.

ASL also utilizes the CPPF to investigate the role of temperature and loading rates in determining and understanding material response to dynamic loading; to detect and characterize stress-induced phase transitions; and to efficiently characterize the dynamic compressive response of materials.

How does a material respond under rapid high-stress compressions?

ASL researchers employ the unique capabilities available through the CPPF to answer this and many other questions important to progress in industry and government enterprise.

What are other advantages of using the Compact Pulsed Power Facility?

Unlike shock waves produced by traditional means of impact loading, in which wave risetimes can be as small as a few picoseconds (10^-12 seconds), the stress waves produced by the CPPF are ramp waves with risetimes of approximately 500 nanoseconds (10^-9 seconds). The longer risetime of these ramp waves results in several important features and efficiencies relative to shock wave loading:

1. the ramp waves produce less entropy than shock waves, resulting in a lower temperature in the compressed material,
2. for ramp wave loading, the wave profile is sensitive to small changes in mass density, such as those that occur in phase transitions,
3. ramp wave loading permits determination of the full dynamic stress-strain loading path of the sample material in a single experiment, compared to the shock loading process where many experiments would be required to obtain the stress-strain response, and
4. the ability to conduct experiments on several samples simultaneously.

How is the ramp wave created?

The CPPF releases energy stored in eight high voltage capacitors in a single pulse, providing a large electrical current (up to 4 million amperes) to the load (metallic panels) in the test chamber. This current pulse produces a strong magnetic field which, in turn, launches a large-amplitude stress wave into the sample. Up to four different samples can be simultaneously subjected to the same stress wave loading. To obtain experimental results, stress wave loading histories are measured using optical interferometry at various locations in the sample. Also, time-resolved optical spectroscopy measurements can be performed on the dynamically compressed samples.