[Getdp] soft iron influence (bis)

Gilles Quéméner quemener at isn.in2p3.fr
Tue Oct 9 11:10:18 CEST 2001


>

Hi,

Here are the answers to your questions in order to better understand
what kind of studies I am trying to perform.

- The field of this magnet is a static one.  In the region where we want to

place some magnetic shielding, it is not  uniform  because it corresponds
to the frining field outside a large toroidal superconducting magnet made
of 8  coils with given numbers of spires.  These coils are of nearly
rectangular
shape with rounded angles and are placed around an axis and separated
by 22,5 degrees making 8 different sectors.

- For this study, before knowing enough of your program, I was planning
to use a precomputed map because I have already such a map. It is used to
perform some electron and proton trajectory  reconstruction/simulation.
This map has been analytically  computed by a Biot & Savart  integration
over all the segments describing the coil windings (there is no other
magnetic
material around). This means that I already have the geometry description
of my source and should be able with some work, to translate it into Gmsh
format for further use within GetDP.

> - do you feel capable of writing approximate equations for the small
> magnetic tubes? Or do you think you could mesh these tubes?

I do not understand what you mean by you first question above, what in
this case means "approximate equations for the tubes"? But anyway, I
certainly can use Gmsh to mesh these soft iron and mu-metal tubes and
place them at the good location w.r.t the source mesh (after playing a
little
bit with Gmsh exanples!)

> I don't have time to write formulations for you (that's your job ;-),
> but I may answer specific questions if you feel capable of developing
> the formulations by yourself.

I fully agree with you and this is the only way for me to learn and try to
understand how to use your software for future uses.

> BTW, do you think you'll have to take the
> nonlinear characteristics of he materials into account?

At this (more than preliminary) stage of my study, I do not know! But I was
guessing
that I have to include this because I was planning to perform this study at
different
excitation currents? But maybe I am totally wrong?

I have learned quite a bit these last days by playing around with your
programs and
by reading some manuals and a few thesis from your lab, but I suppose that
I would
certainly benefit a lot from the reading of Mr P. Dular's thesis, but I
cannot find a
Postscript file of it anywhere. On your lab web pages, there is a list of
publications
with what seem to be clickable indices, but these are not linked to
anythingelse.

Thanks a lot for your help,

                                                    Gilles

--
_______________________________________________________________________________
Gilles Quiminer                     til: (33) (0)4-76-28-40-18
Institut des Sciences Nucliaires    fax: (33) (0)4-76-28-40-04
53, Avenue des Martyrs              http://www.cebaf.gov/~quemener
38026 GRENOBLE cedex FRANCE         http://isnwww.in2p3.fr/hadrons/hadrons.html


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