Some of you may know this experience (Grape + Microwave oven = Plasma video link):
- take a grape that you almost split in two parts, letting just a tiny piece of skin making a link between each half-part.
- put that in a microwave oven, and few seconds later, a light ball which seems to be a plasma appears upon that grape
Looking through google to understand why this phenomena happens, I have found either laconic or partial answers to that question.
In the big lines, this what I understand :
Micro waves seems to create an electric current in the grape because of ions.
- Why do grapes contains ions ?
Suddenly the tiny link between the two half-parts is broken which creates an electric arc
- How is that link broken ?
In parallel, the grape is warmed up and a gas is raised upon the grape
- What is this gas made of ? water ? sugar ?
The combination of the electric arc in that gas creates a plasma
- What is the necessary condition for a gas crossed by an electric arc to create a plasma ?
Is that correct ?
Are there any relevant parameters (microwave frequency, grape size, grape orientation) that make it works ?
Any idea of order of magnitude for the intensity involved, the voltage of such an arc, the temperature reached (I've read 3000 degrees !) ?
Has someone a complete explanation to provide (reference to physical principle would be appreciated !) ?