Does Energy Decay Occur in Sealed Metal Boxes with Excited Resonant Modes?

[apoptosa]

Hey there, I recently solved for the resonant modes in a 3d metal box.

Thats nice, but I was wondering about how to actually excite the modes (its a sealed metal box)
Supposing I actually excited these modes by shining incident em radiation such that a portion [of the incident wave] penetrates by skin effect (assuming the thickness of the metal allows for penetration without too much attenuation).

Will I subsequently have gradual decay of the energy stored in my box? I.e will my resonant mode 'leak' out by a similar process as they were originally excited with?

Thanks-Hopefully that was cogent.

 

[f95toli]

Are you asking how to excite a cavity in your simulations? Or in the real world?
If it is the latter the answer is that this can be done with a small antenna (a dipole of some sort) placed where the mode you want to excite has an anti-node.
The idea is usually (but not always) to make the antenna so small that losses due to the coupling can be neglected (although if you actually want to measure what is inside your box you have no choice but to "tap" some of its energy).
In the undercoupled case most of the losses will be due to the fact that the walls are made from a non-perfect conductor, i.e. just resistive losses.

And yes, the energy in the box will decay exponentially,

 

[charng]

Hello! It sounds like you have successfully solved for the resonant modes in your 3D metal box, which is a great accomplishment. To answer your question about exciting these modes, it is possible to do so by shining incident electromagnetic radiation onto the box. This can cause a portion of the incident wave to penetrate the box, potentially leading to a gradual decay of the energy stored in the box. This decay can occur through a similar process as the original excitation, where the resonant modes leak out. However, the rate of decay will depend on various factors such as the thickness of the metal and the properties of the incident radiation. It is important to consider these factors when designing experiments involving resonant cavities. I hope this helps clarify your question.