Streamers may be great for decorating a child's party, but in dielectrics（电介质）, they are the primary origin of electric breakdown¹. They can cause catastrophic damage to electrical equipment, harm the surrounding environment, and lead to large-scale power outages. Understanding streamers and the mechanisms² behind their initiation³（启蒙，传授）, acceleration⁴ and branching is necessary to devise better solutions to avoid them. As recently reported in the Journal of Applied⁵ Physics, a team of researchers at MIT have developed an accurate 3-D model of streamer propagation（传播，繁殖） that qualitatively⁶ and quantitatively⁷ describes the streamer development, an advance that may impact applications such as medical imaging, aerospace⁸ engineering, power transmission, atmospheric⁹ sensing, natural sciences, sensing technologies and large-scale industry.

 

Whether we realize it or not, every one of us experiences streamers in a phenomenon called electrostatic discharge. When you touch a piece of woolen¹⁰ cloth or a metallic¹¹ object like the body of your car, it is very likely that you sense a tiny streamer discharge which is sometimes painful. These sparks may be the most common streamers that human beings experience in daily life. More than just being annoying, such streamers can be powerful enough to damage expensive electronic devices and even cause fires.

 

In their new paper, Jouya Jadidian and his team at the Massachusetts Institute of Technology (MIT) took a comprehensive approach to their study of streamers.

 

"Our modeling results are understandable even for someone without advanced knowledge of physics, since we have generated very intuitive 3-D plots of streamer tree structures that helps streamer branching mechanisms to be simply inferred," he said.

 

The model also relates the physical attributes of streamers to tangible¹² circuit parameters¹³ measured in ordinary laboratories such as voltage, current and time-delay. The results have proven highly accurate given an extraordinary resemblance（相似） between modeling results and experimental images taken from the light emitting streamers. Jadidian's research in this area has been awarded the IEEE Guenther Award and the Chorafas Foundation Award in 2013.

 

The development of this model involves some real challenges. Although 3-D imagery in gases is doable using current technology, streamer imaging in liquid dielectrics is extremely difficult. Creating a comprehensive 3-D streamer model also imposes significant numerical burden that requires very efficient modeling code and powerful computational tools. "The molecular¹⁴ structure and behavior of liquids are more complex than gases and solids, and even in the purest liquids, there are trace amounts of impurities¹⁵ that make it difficult to isolate¹⁶ the mechanisms behind electrical breakdown," Jadidian explained.

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