Designing Shielding Box for High Voltage Cylinder

[india]

i have to design one shielding box. in that there is cylinder having high voltage +60kev. and box having metal plate. so i have to calculate the electric field on that cylinder and then decide , what should be the distance in between plate and cylinder. i have attach the geometry on the file. please see it.

 

[india]

Could anyone help me ?

 

[mfb]

Can you use some approximation, like d>>R?
In that case, it should be possible to approximate the box as a cylinder, and calculate it like a cylindrical capacitor using Gauss' law (google should give you some ways to do this).

If not, a numerical simulation might be the easiest way to solve your problem.

 

[india]

yes, thanks ... bt i think i wl get that for cylindrical capacitor. bt right now i have another design.. bt i wl try for solving it.
btw what type of numerical solution that i should use??

Can you use some approximation, like d>>R?
In that case, it should be possible to approximate the box as a cylinder, and calculate it like a cylindrical capacitor using Gauss' law (google should give you some ways to do this).

If not, a numerical simulation might be the easiest way to solve your problem.

 

[Bob S]

For a cylinder and one metal plate, the capacitance per unit length is given by Smythe Static and Dynamic Electricity 3rd edition page 78:
$$C=\frac{2\pi\epsilon}{cosh^{-1}\frac{h}{R}}$$
for cylinder of radius R with axis parallel to and at a distance h above an infinite plane. The problem of a cylinder between two conducting planes is given on page 105.

 

[mfb]

btw what type of numerical solution that i should use??

A two-dimensional grid, for example. Use your favourite tool, plug in the boundary conditions for the potential Φ (box and circle) and the Laplace equation $\nabla^2 \Phi = 0$ in the vacuum (or air, as good approximation).

In excel, the result can look like http://s7.directupload.net/file/d/2824/7fhjuxw8_jpg.htm (I did this for a cylinder over an infinite plane orthogonal to the cylinder axis, and it uses cylindrical coordinates).