Re: request for coordinates

[<y.guangliang@physics.gla.ac.uk>]

Dear Richard and Tim,

   The diamond crystal is located at (0, -300 cm, 0), the x axis is
   pointing to the focal plane direction in the horizontal plane, y axis
   is along the photon beam axis, while the z direction is the vertical
   direction.
   I should say the effect field boundary and the distance from the
   effective field boundary to the magnet pole edge are two different
   things. When I design the tagger, the first thing I should know is
   where the effective field boundary is. Depending on the materials and
   pole profiles etc., the distance from the effective field boundary may
   change, but location of the effective field boundary should be fixed.
   For an ideal magnet with an abrupt field boundary, the effective field
   boundary is along the magnet edge.

Cheers

Yang


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> Yang,
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> I don't know how to use the "effective field boundary" as a definition
> for the origin.  It keeps me running in the following circle.
>
>  Where exactly is the effective field boundary?  I need a map to
> know, go to 2.
>
>  Where is the origin of the map?  I need a coordinate system to
> know, go to 1.
>
> Please rescue me, I am getting dizzy!  Can you tell me relative to
> something I know, like the position of the crystal on the beam axis?
>
> Richard Jones
>
>
> Guangliang Yang wrote:
> Dear Richard,
>
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>    The intersection of the photon beam trajectory and the
> effective field boundary of the magnet is the location of the origin in
> my Tosca simulation.
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>    Now I am doing final Tosca calculation for the single
> magnet tagger.  I will send you the map you requested once I
> finish it.
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> Cheers
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> Yang
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> ----- Original Message ----- From: "Richard Jones"
> <richard.t.jones@uconn.edu>
>
> To: "Yang Guangliang" <y.guangliang@physics.gla.ac.uk>
>
> Cc: "Hall D beam working group" <halld-tagger@jlab.org>
>
> Sent: Tuesday, September 09, 2008 3:12 PM
>
> Subject: request for coordinates
>
>
>
>  Yang,
>
>
> Can you tell us your convention for the coordinate system you are using
> in the Tosca plots in your report?  We are trying to locate the
> microscope in the tagger hall coordinates, and we are not sure where
> your origin is. You might add a sentence in your report giving this
> information, and also the coordinate system orientation which seem to
> be different from the one we are using to describe the tagger hall
> geometry in the simulation and drawings.  For the moment, we just
> need the location of the origin, if you could forward those to us.
>
>
> As soon as possible, it would be great to get a new field map from you.
> The grid you used for the map of the two-dipole design would be fine.
>
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> thanks,
>
> Richard Jones
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