Re: tagger field map

[Elke-Caroline Aschenauer <elke@jlab.org>]

On Mon, 12 Jan 2009, Alexander Somov wrote:

Dear Sascha,

as Tim already pointed out, we shift our things.
the tagger magnet and if needed also the quad. This is easiest because it
does not involve any other parties like the machine group. And there is
enough space in the tagger hall to do that, so please take this mail as a
decission.

thanks elke



> Date: Mon, 12 Jan 2009 09:24:57 -0500 (EST)
> From: Alexander Somov <somov@jlab.org>
> To: Tim Whitlatch <whitey@jlab.org>
> Cc: Guangliang Yang <y.guangliang@physics.gla.ac.uk>, halld-tagger@jlab.org
> Subject: Re: tagger field map
>
>
> Good morning,
>
> Yang thanks for the information.
>
> The question is should we shift the magnets or the
> electron beam pipe which goes to the dump (downstream
> by 19.6 cm)?
>
> Should we shift the quadrupole magnet as well (or one can
> simply change the quadrupole's field) ?
>
> Cheers,
>         Sascha
>
>
>
>
>
>
>
>
> On Mon, 12 Jan 2009, Tim Whitlatch wrote:
>
> > Good morning all,
> >
> > We do not wish to change the Tagger hall. Is there an exact number that we
> > should shift the magnet by? Or is 20cm fine?
> >
> > Thanks,
> >
> >      Tim
> >
> > Guangliang Yang wrote:
> >> Dear Sascha,
> >>
> >>    The number in table 4.2 was calculated for the two dipole tagger. It is
> >> not correct for the single magnet tagger.  If we don't want to change the
> >> tagger hall design, we should shift the tagger downstream by ~20 cm.
> >>
> >>
> >> Cheers
> >>
> >> Yang
> >>
> >>
> >>
> >> ----- Original Message ----- From: "Alexander Somov" <somov@jlab.org>
> >> To: "Richard Jones" <richard.t.jones@uconn.edu>
> >> Cc: <halld-tagger@jlab.org>
> >> Sent: Friday, January 09, 2009 3:53 PM
> >> Subject: tagger field map
> >>
> >>
> >>>
> >>> Hello Richard,
> >>>
> >>> The magnetic field map in the tagger hall seems
> >>> to be shifted by a few cm in the MC.
> >>>
> >>> According to the table 4.2 in the technical design
> >>> report (updated for the review), the position of
> >>> 12 GeV electrons at z=26.301 m should be x = -4.7576 m.
> >>> However, I get x = -4.803 m, see the plot attached.
> >>> Are the numbers in the table 4.2 correct ?
> >>>
> >>> I used the same reconstruction code as before but just
> >>> replaced the magnetic field map (do I need to shift the
> >>> map ?)
> >>>
> >>> Could you please check. I want to finish with updating
> >>> geometry asap.
> >>>
> >>> Thanks,
> >>>        Sascha
> >>>
> >>> P.S. The full-energy deflection angle in the magnet is
> >>> correct, 13.4 deg.
> >>>
> >>>
> >>
> >
>
>

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