TITLE: How to generate a strong electromagnetic field?
QUESTION [0 upvotes]: I'm working on a project and I need help generating a strong magnetic field over an air gap with the lowest material weight that could be achieved.  I have tried to use permanent magnets but its not effective so I need to know the best way to generate a strong fixed electromagnetic field with the lightest material.
The attached image is a simple drawing shows the direction I need to generate the field in the boxes are the field source:$\hspace{150px}$.

REPLY [1 votes]: The magnitude of electric field at a point due to an infinite plane sheet of uniform charge density is independent of its distance from the sheet.  
Mathematically, from gauss law magnitude of electric field at a point due to an plane charged sheet is given by the following equation: 
$$E=\frac{\sigma}{2\epsilon_0}$$
where $\sigma$ is surface charge density, $\epsilon_0$ is the absolute permittivity of the free space.  
As you are asking for the strong electromagnetic field, for the electric field I would suggest you to use plane sheet of uniform charge density, as you increase the charge density, field will increase. The advantage is that intensity of electric field will not reduce even at large distance from the sheet. I don't know how you would manage to have such sheet, but little approximated one would help.  

For magnetic field, you can't have a plane sheet as you had for the purpose of electric field, the reason is magnetic monopole don't exist. For the magnetic field you can make a solenoid with its axis in the region where you want field.
{"set_name": "stack_exchange", "score": 0, "question_id": 100721}