|
-------- Original Message --------
Yes, it will help in some extend. In our caloromitere we have it. Lubomir > Thanks Lubomir. Do you think that by adding pressure from the sides to > squeeze the blocks together will help? > > Tim > > Lubomir Pentchev wrote: >> Hi Tim, >> >> The problem is that there is a pressure on the back of the glass from >> the PMTs (I estimate it about a pound per tube), which is about 2 tons >> in >> total, and that the glass is wrapped in mylar that slides easily. We >> have >> a thick enough front plate that keeps the glass in place, but during the >> installation, testing or UV curing we have to take it out. In principal >> the >> static friction is enough so that the blocks don't slide. However during >> the installation of the PMTs when the front plate was out we had to lift >> the calorimeter a little bit to install some cables. Just lifting it >> from >> the ground created an impulse and the glass slided. The shift was about >> 5mm on the top where the friction was smallest and that shift decreased >> linearly down to zero at the bottom. >> We fixed it simply by re-stacking the glass. >> >> I would be happy to help you if you had any other questions concerning >> the >> design of the calorimeter. >> >> Lubomir >> >> On Thu, 14 Feb 2008, Tim Whitlatch wrote: >> >> >>> Hi Lubomir, >>> >>> I remember during the Hall D interview, you mentioned something about >>> the lead glass blocks moving after applying pressure to seat the PMT's. >>> Can you please explain to me what the problem was and how it was fixed? >>> >>> Thanks, >>> >>> Tim Whitlatch >>> >>> >>> > > |