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infinitely growing field from a transient dipole
Posted 2012/02/07 5:41 GMT-5 Low-Frequency Electromagnetics, Charged Particle Tracing, RF & Microwave Engineering, Wave Optics, Particle Tracing for Fluid Flow, Studies & Solvers Version 4.2 0 Replies
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so I am still working on exciting a gold nano chain with a dipole.
For now on the Basis of this paper (Maier 2003), just to get the hang of what I am actually doing.
(Maier 2003) authors.library.caltech.edu/2448/1/MAIprb03.pdf
For reference also previous discussion pages
www.comsol.com/community/forums/general/thread/25670/
www.comsol.com/community/forums/general/thread/16892/
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So after that brief overview to the actual problem at hand:
I have been making some progress in understanding COMSOL and what I want it to do, but it is still not working the way I would expect it to.
The Problem is that the Electromagnetic field that is coupled from the dipole into/onto the gold nano chain just grows continuously. ie. after every time step the field amplitude will have grown a few orders of magnitude. This is obviously not desirable and wrong.
What I have so far been able to tell is that this behaviour is somewhat dependant on the time stepping settings for the transient solver. (Thanks again to Ivar for pointing out that I should use manual settings in order to stop erratic behaviour)
The settings that are currently set in the attached model file cover a time range of: range(0,5.0e-17,1.0e-14) with a manual set interval of 5e-17
Regarding the Ex field for the different time steps the before mentioned behaviour of amplitudes that are spiralling out of control can be seen.
decreasing the time step size by a factor 10 to 50e-17 this behaviour is not directly apparent, it is however visible again when also increasing the regarded time frame.
this leads me to assume that the problem lies at least partially somewhere else as it occurs no matter how the range and or time step for the transient solver are specifically set.
I am however at a loss as to what it might be or how I could possibly narrow the search down.
So Any pointers would be very much appreciated!
What just seriously bugs me is that the wave coupling from the dipole to the nano chain seems to work like a charm in the frequency domain but is screwing me when trying to view the transient behaviour, it is somewhat frustrating.
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Hello Fantatier
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