sPHENIX HCal discussion

[Edward Kistenev <kistenev AT bnl.gov>]

Hi Megan, 
I wander if comparing lite intensity on both ends of the fiber exiting 
towards SiPM can be a very best test to identify problematic tiles (embedding 
defects). Human eyes work rather well to see if one of the fibers is damaged 
but trivial $15 microscope coupled to phone and pictures in raw format should 
be even better (look through EMC discussion of visible fiber counting in EMC 
blocks) to find two fibers and compare their luminous properties. You will 
have access to tiles already wrapped so the light into tile must be injected 
through the fiber window (460 nm or close - it must travel as far as possible 
through the tile plastic and WLS fiber) but manufacturer will have access to 
tiles before wrapping and there should be no problem to expose tile to day 
light and take identifiable file with high resolution picture for your 
students to analyze. 
What do you think of proposing this challenge to undergrads this summer.
                        Edward