electrostatics and FEMM

[frank.e.lenning@xxxxxxxxxx]

I've been playing a little trying to do electrostatics problems within 
FEMM in a similar way suggested by Roberto Brambilla in message 180. 
After some thought, though, I can't figure out why you can't do 
axisymmetric electrostatic in FEMM. It seems like both satisfy a 
Poisson's equation and so you should be able to equate the proper 
quantities to do it. 

Trying this out though I have run into some subtle problems with the 
way FEMM handles axisymmetric. First, I can't seem to be able to set 
A on a boundary internal to a problem space. I have tried prescibing 
A on a boundary and I get something that looks more like FEMM has set 
A/r to some constant (when I set A0=1). Second, FEMM seems to default 
the axis of symmetry boundary to A=0 and will not allow me to change 
it. For axisymmetric electrostatics problems, I'd like to set dV/dn 
to zero along this boundary but it doesn't seem to let me. The 
specific problem I'm trying to do is two cylindrical conductors 
(aligned end-on on the r=0 axis) of finite length at opposite 
potentials. Any suggestions??