CST - Electric field simulation of accelerating cavities

I am planning to use the CST Studio Suite to simulate the electric field generated in an "accelerating cavity" used in accelerators.
The structure consists of two copper cylinders (inner and outer conductors) that are short-circuited on one side. A magnetic alloy is inserted inside.
I would like to simulate what kind of electric field is generated inside these two conductors when a voltage of 200V 10MHz is applied to them.
So my question is, what kind of solver should I use to do this kind of simulation? Since I will be using magnetic alloys, I would think a low frequency solver would be suitable, is that correct? The license is an academic license.
Also, what kind of operation do I need to do to apply AC voltage?