Re: question on pair spectrometer shielding

[Richard Jones <richard.t.jones@uconn.edu>]

Alex,

Aha, ok.  Those arc-shaped plates shown in the assembly drawing attached 
to the ends of the yoke are actually the cover plates for the coils.  At 
the end of the magnet, the coils bend up/down away from the gap and wrap 
up over the yoke to connect across the front and back of the cores.  The 
only iron in those is a 1/2" steel plate that serves as a cover and 
support for the return arcs of the coils.  I will modify the geometry to 
better represent the inner PS geometry.  Thanks for the explanation.  
When I first saw it I thought perhaps you had added additional iron 
there for shielding purposes.

-Richard Jones


Alexander Somov wrote:
>
> Hello Richard,
>
> Sorry, I understand what you have asked now :)
>
> Here is how I simulated the magnet and the vacuum
> chamber:
>
> According to the magnet specification, a nominal effective
> length of the magnet is 72'' ( 1.83 m). However, there is
> an additional 7'' plate attached to the side of the magnet
> (of course this plate would change the field on the edge).
>
> PS hodoscope counters should be installed 1.5 m from the
> effective field. Sizes and positions of the counters are choosen
> according to  1.64 T field, 1.83 nominal effective length of
> the magnet, and 1.5 m fly distance from the magnet.
>
> -----------
>
> In the simulation I assumed that the magnet consists of two
> pieces:
>         - 1.83 m long piece with a magnetic field
>         - 17.8 cm piece without the field
>          (used to simulate more realistically scattering on the
>          magnet's aperture)
>
> Of course the magnetic field map has to be simulated.
> I just put in a model into geometry.
>
> The magnet is followed by a 150 - 17.8 = 132.2 cm long
> vacuum chamber, so that the counters are positioned 1.5 m
> away from the magnet's effective field.
>
>
> Cheers,
>        Alex
>
>