Re: CDC configuration

[Tim Whitlatch <whitey@jlab.org>]

Friday morning 9:30 is good for me.

Tim

Beni Zihlmann wrote:
> Hi All,
>
> I had some information exchange with Slava this morning. And I 
> realized many
> different parameters and issues regarding the end-plate are not 
> familiar to everybody.
> like the following:
> 1) from mechanical tolerances there need to be a "gap" between tubes
>     in a given layer of about 0.1mm to 0.15mm depending on the tolerances
>     of the tube itself and its parts at the end.
>     this is true not just at the end-plate but also at the center of 
> the CDC for axial and stereo layers.
>     Distances of 20 micro meters between straws is not realistic 
> considering that there are no
>     numbers available for tolerances of the tube diameter, wall 
> thickness, glue joints, etc.
>
> 2) at the same level one could rather change the number of tubes in a 
> given layer then changing
>    its radius and play with the gap between straws (-> point 1)
>
> 3) there needs to be sufficient spacing after the last straw for the 
> gas cover sheet and
>    the support rods (about 1.9") as well as the suspension mechanism.
>
> 4) since the straws have to be custom made one could think of make 
> them a few micro meters
>    smaller in diameter to fit 28 layers in the allocated space.
>
> 5) the holes into the end plate have to be specified with position and 
> angle such that a CNC machine
>    can be programmed accordingly.
>
> 6) ...other points ??
>
> we really need a meeting to discuss this with all parties involved to 
> settle all the issues once and for all.
> If we could meet still this week would be great.  How about
> Thursday late afternoon say 4:00pm  ?
> or Friday morning         say  9:30am ?
>
> cheers,
> Beni
>
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