Gas Cherenkov - some info on the costs

[gen (Eugene Chudakov) <gen@jlab.org>]

Hall D PID Mail List:


I found some information concerning the mirrors and gas purification
from a Hall A group developing a threshold Cherenkov with a C4F10 radiator.
The figures come from Nov,2006.

At FNAL and Hall B the purification is done by simple and cheap
filters. It seems that the cost can be in a 10k range. The gas was $200/kg.
The mirrors were $500 per a 30x30cm**2.

This may translate to: 
a) gas: 300kg needed to fill the box = $60k. We would need probably
   50% more, so an estimate is $100k
b) purification: 20k 
c) mirrors - there are several companies willing to build and coat small
   mirrors (30x30cm**2). Some provide a good quality surface just from 
   the mold. One may consider making a mosaic from about 200 mirrors
   (50 for the 1-st ring and 150 for the 2-nd): $100k in total. 
   CERN can coat larger mirrors, but will ask for more money/mirror.

In summary, gas+mirrors amount to $220k

Eugene