Re: exhalo drawings

[Peter Winter <peter.winter@psi.ch>]

Dear all,

I also looked at your drawings and I haven't found any obstacles. I 
reviewed that we can really push in far enough to reach the center of 
the beamline for being able to turn by 180 degrees. Since the NW320 
beampipe has a radius of ~16 cm, we'd maximally need this as being 
movable. Since the aluminium tube around the light guide is 26 cm and 
the feedthrough is <10cm, it's fine to me.
Just a few comments left from my point of few:
- In your drawing the two scintillators are mounted by 90 degrees. We 
could also have them opposite at 180 degrees. I cannot really think of 
any disadvantages / advantages for both options since we'll anyhow 
rotate in phi to scan the different regions.
- Concerning the connection of the plexi glas and the aluminum 
protection: With respect to the vacuum glueing both together is never 
good as the vacuum . But since that might be the only option we will 
probably do that. I can ask Mr Bracher later if he (as the scintillator 
and lightguide expert at PSI) has some better idea.
- The vacuum group will order the special dynamic feedthrough components 
and they'll prepare the drawings for our dimensions. I will then figure 
out where we can build the different parts (workshop east or west).
- During the time period where I'm gone you can always contact Claude 
and ask him to help with the local communication. He just agreed on that.
- Does the plexi tube need any special treatment at the ends (like a 
notch for the UIUC light guide or is a flat surface fine?
- Concerning the scintillators: For the APD preparation we have three 
100x10x1mm scintillators. We also have a larger piece left from Peter's 
reserve from which we could get 2 pieces at 100x20mm. However, this is 
only 0.5mm thick.
Peter

-- 
Dr. Peter Winter
OBEA 10/A
Paul Scherrer Institut
CH-5232 Villigen-PSI
Tel: +41 56 310 4786
Fax: +41 56 310 5353