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[lcdds 102] Re: Some comments on proposed muon chambers

Subject:   [lcdds 102] Re: Some comments on proposed muon chambers
From:   Mark Thomson <thomson@xxxxxxxxxxxxxxxxx>
Date:   Mon, 1 Aug 2005 09:30:40 +0100 (BST)

Hi,

I agree - this would need some absorber (perhaps a few radiation lengths
to cut out soft photons/electrons from EM interactions in the coil).

                    cheers,
                          Mark.

On Mon, 1 Aug 2005, yamamoto222-ee@xxxxxxxxxxxxxxxx wrote:

> Dear all,
> 
>    Having one layer of muon system before any yoke material sounds
> like a good idea. It may need some kind of absorber, though, to avoid
> low energy components to be a nuisance. Some full simulation study
> would be nice (to be completed at Snowmass? - volunteer?)
> 
>    Best
> 
> - Hitoshi
> 
> 
> 
> 
> 
> At 11:54 AM +0100 05.7.29, Mark Thomson wrote:
> > Dear Colleagues,
> > 
> > A few thoughts about the GLD baseline muon detectors (based on my
> > experience on MINOS).
> > 
> > MINOS uses 8m long 1cm thick scintillator strips read out by WLS
> > fibres and 16 pixel PMTs (Quantum efficiency of ~0.18). For a
> > minimum ionsizing particle the total number of observed PEs
> > is approximately 10 when summed over both strip ends. Even with this
> > modest QE and 8m long strips (which are not particularly thick) we
> > almost always see a hit from a MIP. Gaps between adjadcent strips
> > are not particularly important (<0.5% of muons sneak through).
> > 
> > For the baseline having two orthognal layers of thickness ~1.5cm
> > in between the return yoke gaps would almost certainly work well.
> > This would enable the gaps between yoke sections to be reduced
> > to 5cm.
> > 
> > One additional suggestion, how about having the first layer of
> > muon detectors immediately before the return yoke, i.e. after
> > the coil. This would extend the efficiency for "tail-catching"
> > to lower momenta.
> > 
> >      cheers,
> >                              Mark.
> > 
> > p.s. does anyone know the coil thickness in hadron interaction lengths ?
> > 
> > +---------------------------------------------------------------------+
> > |  Dr. Mark A. Thomson                 University of Cambridge,       |
> > |  E-mail: thomson@xxxxxxxxxxxxxxxxx   Cavendish Laboratory,          |
> > |  Phone:   44 1223 765122             (Room 951 Rutherford building) |
> > |        or 44 1223 762332 (College)   Madingley Road,                |
> > |  Fax:     44 1223 353920             Cambridge, CB3 0HE, U.K.       |
> > |  http://www.hep.phy.cam.ac.uk/~thomson/                             |
> > +---------------------------------------------------------------------+
> 
> 

+---------------------------------------------------------------------+
|  Dr. Mark A. Thomson                 University of Cambridge,       |
|  E-mail: thomson@xxxxxxxxxxxxxxxxx   Cavendish Laboratory,          |
|  Phone:   44 1223 765122             (Room 951 Rutherford building) |
|        or 44 1223 762332 (College)   Madingley Road,                |
|  Fax:     44 1223 353920             Cambridge, CB3 0HE, U.K.       |
|  http://www.hep.phy.cam.ac.uk/~thomson/                             |
+---------------------------------------------------------------------+