PEA systems

This is a typical PEA measurement unit. A commercially available unit has the resolution of 10 microns. The sensor is either PVDF or LiNbO3.
The resolution of our extremely high resolution system is about 2 microns.
Temperature controller is also available as an option.

How is the profile in the lateral direction?
The space charge distribution in vertical and lateral directions of the applied pulsed electric field can be observed by using an acoustic lens sensor. The sensor can move rapidly and the position is controlled by an X-Y positioner. While you are measuring, the location and the charge density are displayed at the same time. The output signals are deconvoluted, calibrated and displayed automatically during the measurement. Recently, the resolution in the lateral direction has been dramtically imporoved. It will be presented in 2004.

Here is an example. The specimen had an evaporated electrode shaped the letter 'C' between the two PET film. When a positive dc voltage was appliedto the letter C electrode, positive charge appeared at the position of the letter C, then negative induced charges appeared on the electrodes, which sandwich the specimen. Inside the PET film, on the other hand, no charge appeared.

There is a demand for a space charge measurement of products, on site, i.e., in the factory. The system must be very small, and the signal should be displayed directly on the oscilloscope. And the whole system should be operated with a battery.
We developed a very small PEA electrode unit, and mounted on a clamp.

On-site, or in situ measurement, however, has not been done except a few examples during the breakdown tests of dc power cables. We have developed a portable clamp type PEA system which can measure space charge on site. The electrode tip is mountable to other equipment such as a vacuum chamber, in order to observe the space charge phenomena during the irradiation or plasma treatment of various materials.