Re: question to material in geometry

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

On Tue, 22 Jan 2008, Tim Whitlatch wrote:

Dear Tim,

thanks a lot. I think we have to see from MC what influences the rates
least. I would naively assume rohacel, but we should check.
I guess an other point for the MC-geom to do list.

cheers elke



> Date: Tue, 22 Jan 2008 11:33:40 -0500
> From: Tim Whitlatch <whitey@jlab.org>
> To: Elke-Caroline Aschenauer <elke@jlab.org>
> Cc: Richard Jones <richard.t.jones@uconn.edu>,
>      Matthew Shepherd <mashephe@indiana.edu>, halld-mc@jlab.org,
>      halld-me@jlab.org
> Subject: Re: question to material in geometry
>
> Hi Elke,
>
> A quick calculation shows a wall thickness of 4mm  steel (the entire
> 45cm length) needed to keep deflections down below 100 microns.This is
> assuming a 2mm thick round tube inside a 2mm thick square tube. This
> will need to be made special. Some other design using rohacel machined
> flat and glued to a thin walled smaller tube may be possible.The rohacel
> would be muck thicker, but may buy us something.
>
> Tim
>
> Elke-Caroline Aschenauer wrote:
> > On Mon, 21 Jan 2008, Richard Jones wrote:
> >
> > Dear Richard,
> >
> > thanks for the answer. I think the best would be to put the material Tim
> > is intending to put to support the lead glas blocks. Tim some rough
> > numbers please?
> >
> > Thanks elke
> >
> >
> >
> >> Date: Mon, 21 Jan 2008 11:14:37 -0500
> >> From: Richard Jones <richard.t.jones@uconn.edu>
> >> To: Elke-Caroline Aschenauer <elke@jlab.org>,
> >>      Matthew Shepherd <mashephe@indiana.edu>
> >> Cc: halld-mc@jlab.org
> >> Subject: Re: question to material in geometry
> >>
> >> Elke,
> >>
> >> There is currently no support material to hold the FCal blocks around
> >> the beam hole.  I propose to add an iron sleeve of  a new mm thickness.
> >> Matt, do you have a recommended thickness for that?
> >>
> >> Adding a helium bag down the beam line after the target is a good idea.
> >> I have it on my to-do list.
> >>
> >> Richard Jones
> >>
> >>
> >> Elke-Caroline Aschenauer wrote:
> >>
> >>> Dear Richard,
> >>>
> >>> I have a small question to the material in the geometry file.
> >>>
> >>> For the FCal beam hole do you have any material in there. Of course I mean not completely filled but some frame/tube is needed to support the blocks.
> >>>
> >>> One other question on the performance with the detector is if we would put a helium bag going from the end of the FDC through the empty cerenkov space to the tof, through the fcal to the photon beam dump.
> >>>
> >>> I can add this 2 items concerning geom-file on the wiki.
> >>>
> >>> cheers elke
> >>>
> >>>
> >>>
> >>>  ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
> >>>   )    `\                                                  -
> >>>  /    '. |                                                  +
> >>>  |       `,              Elke-Caroline Aschenauer            =
> >>>   \,_  `-/                                                    -
> >>>   ,&&&&&V         Jefferson Lab                                +
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> >>>
> >>>
> >>>
> >>
> >
> >  ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
> >   )    `\                                                  -
> >  /    '. |                                                  +
> >  |       `,              Elke-Caroline Aschenauer            =
> >   \,_  `-/                                                    -
> >   ,&&&&&V         Jefferson Lab                                +
> >  ,&&&&&&&&:       HALL-D 12C / F381       121-A Atlantic Avenue =
> > ,&&&&&&&&&&;      Mailstop: 12H5          Hampton, VA 23664      -
> > |  |&&&&&&&;\     12000 Jefferson Ave                             +
> > |  |       :_) _  Newport News, VA 23606  Tel.:  001-757-224-1216  =
> > |  |       ;--' | Mail:  elke@jlab.org    Mobil: 001-757-256-5224   -
> > '--'   `-.--.   |                                                    +
> >    \_    |  |---' Tel.:  001-757-269-5352                             =
> >      `-._\__/     Fax.:  001-757-269-6331                              -
> >             +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+
> >
> >
>

 ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
  )    `\                                                  -
 /    '. |                                                  +
 |       `,              Elke-Caroline Aschenauer            =
  \,_  `-/                                                    -
  ,&&&&&V         Jefferson Lab                                +
 ,&&&&&&&&:       HALL-D 12C / F381       121-A Atlantic Avenue =
,&&&&&&&&&&;      Mailstop: 12H5          Hampton, VA 23664      -
|  |&&&&&&&;\     12000 Jefferson Ave                             +
|  |       :_) _  Newport News, VA 23606  Tel.:  001-757-224-1216  =
|  |       ;--' | Mail:  elke@jlab.org    Mobil: 001-757-256-5224   -
'--'   `-.--.   |                                                    +
   \_    |  |---' Tel.:  001-757-269-5352                             =
     `-._\__/     Fax.:  001-757-269-6331                              -
            +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+