How many joules --> e.m. waves?

[LUDWIK KOWALSKI <kowalskil@alpha.montclair.edu>]

On 15 Apr 97 16:58:08 Al Bachman wrote:

> Isn't part of the difficulty modeling the switch? If you consider a simple 
> knife switch (one conductor approaching another), it clearly forms a charged 
> variable capacitance system until the gap becomes so small that a discharge 
> through the breakdown of air occurs. A real circuit will also have some 
> inductance, however small. These effects are generally very brief, among 
> the 'transient effects' that we neglect.

Yes, the problem is devoted to to the transint effect. The effective
capacitance of the switch does play a role but that role is not dominant 
because C=0.01 F is very large. Conceptually the contact area can be seen
as negligibly small. We know what happens; the challenge is to make a
correct quantitative prediction. My intuitive prediction is that at least 
5% of the initial energy is radiated under the specified conditions.

Yes, the inductance of the wire loop is essential and that is why the 
geometry of the arrangement was defined. Can somebody supply the formula 
for L of a single coil; my rough estimate (by Fermi method) is 0.02 microH.

                                          Ludwik Kowalski