Breakdown_voltage_coaxial_line
I can not use this wonderful file cause no MathCAd software.Could you tell mw the theory base of your calculation?If your computation method can expend for dielectrical breakdown voltage?Thanks very much!
Attached is a screen shot of the page with the formulas. This assumes perfectly smooth conductors and no safety factor which is usually 2x.
This method is founded on a theory of Electric Force and Energy.
Very simple this computation method was described in the book -
Liang Chi Shen,Jin Au Kong,"Applied Electromagnetism " ,3-rd edition,1995, pp.362-379.
In this book , also, your can find computation methods for coaxial lines, cables with multiple layers of Insulation.
You can use these method's for calculation breakdown voltage for coaxial lines and coaxial capacitors with any dielectric (insulator), if you know relative permittivity of dielectric.
If you dont have MathCad you can use the next attachments file.
This is interesting, but I'd like to point out that the breakdown calculation presented has assumptions that must be considered. Usually there are multiple mechanisms that could initiate breakdown in cables. Depending on the dielectric material properties, there are often microscopic pores that are filled with a gas that can be nucleation sites for prebreakdown ionization. These pores often breakdown below the intrinsic dielectric strength and cause ionization that will eventually lead to catastrophic failure. There are many documents discussing this phenomena and began with Paschen's investiagtions about the significant parameters that determine the ionization integrals, such as the partial pressures, pore radius..etc.
regards,
MoonShine
You can also look up same discussion in Pozar