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Electric field enhancement on the tip in electrostatic module

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Hello all,
I am beginer in Comsol and now trying to model electric field redistribution in dielectric between cathode and anode. Where, cathode has shape of the tip of defined radius. I placed geometry and materials in the model and computed with Electrostatics module. However, didn't find yet how to add physics of field enhancement phenomena (e.g. dependence of radius of tip, the height of the tip etc).
So the question is how to model this object? The example model or a tutorial will help alot.

Best regards

1 Reply Last Post 14.09.2016, 17:36 GMT-4
Robert Koslover Certified Consultant

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Posted: 8 years ago 14.09.2016, 17:36 GMT-4
If you know already how to model a simple parallel plate capacitor, then you know how to solve this problem too. You don't have to add any special physics to model the enhancement to the electric field at the tip of the electrode. The electric field is computed/available when the electrostatic solution (the potential) is found. So assign potentials to your cathode and anode (much like you would to the plates of a capacitor), solve the electrostatic problem, and then plot the fields. Be sure to use a fine mesh in the vicinity of the tip so that you minimize numerical errors there.
If you know already how to model a simple parallel plate capacitor, then you know how to solve this problem too. You don't have to add any special physics to model the enhancement to the electric field at the tip of the electrode. The electric field is computed/available when the electrostatic solution (the potential) is found. So assign potentials to your cathode and anode (much like you would to the plates of a capacitor), solve the electrostatic problem, and then plot the fields. Be sure to use a fine mesh in the vicinity of the tip so that you minimize numerical errors there.

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