In reply to Horace Heffner's message of Tue, 11 Mar 2008 09:43:54 -0800: Hi Horace, [snip] >It sounds like you are assuming the two tori major axis planes are >parallel as well, both normal to the axis.
Correct. >If the radii are small in >comparison to the distance between the tori, and the major axes >planes are parallel and normal to the axis, and there is no high mu >material involved, then the force just boils down to the force >between hoop coils at that distance. If mu1 and mu2 are the hoop >coil magnetic moments, and d the separation between axis centers, >then the force is: > > F = =3*mu0*mu1*mu2/(2*Pi*d^4) > >If there is no magnetic core material, i1 and i1 the currents, r1 and >r2 the major radii, then > > mu1 = pi*i1*(r1)^2 > > mu2 = pi*i2*(r2)^2 > >Torque depends on angle to the axis and is proportional to the 1/d^3 >dipole field strength of the hoop current. > >Again, this all assumes d is large in relation to r1 and r2. As >things get closer they change significantly, and the best way to >handle force and torque calculations is probably finite element >analysis. > >What is your application? What are the dimensions involved? Are you >dealing with actual toroid coils, or merely using them as mental >models for orbitals or other physical realities? How very astute of you. :) I'm looking for an additional force significantly stronger than that between two hoop coils, in order to correct my Helium model. If I haven't made a mistake, then the normal hoop coil force would be orders of magnitude too small, which is why I was initially considering possible interaction forces between individual minor loops. I'm guessing (without yet having made the effort to work it out correctly), that there would be about 1/fine_structure_constant minor loops in each "coil". There is also the consideration that when wire is used in a real coil, there is a positively charged lattice through which the electrons move (i.e. the metal ions in the wire), whereas when considering a single electron as a coil, there is no such lattice, so perhaps our laws of magnetism (which were derived from real wires), don't apply in exactly the same way. Regards, Robin van Spaandonk The shrub is a plant.
