sPHENIX EMCal discussion

[Craig Woody <woody AT bnl.gov>]

Hi Mike,
  Very nice study. The results seem to make sense, and it's good to see that there is at least some reasonable agreement with Sean's measurements. Qualitatively it shows what you would expect, namely, that if we increase the readout area by increasing the tower size and stay with 4 SiPM, we loose in total light collection efficiency and increase our non-uniformity. However, it looks like we can recover that back by adding more SiPMs. As I said in my last E-mail, I'm not sure that results in any real cost savings, especially since we don't know that we can build the larger modules as 2D projective, but it's good to know what the impact on the light collection would be if we did. One small suggestion for your slides would be if you could add the rms/mean values for each of the uniformity plots, and make a table summarizing all of the results and numbers, it might make it easier to see the whole picture as to what is going on.

Cheers,
Craig

On 5/30/2016 8:13 PM, Phipps, Michael William wrote:

Hi all,

Following up on the EMCal segmentation discussion from last week, we've done a series of geant simulations to test the lightguide uniformity/efficiency at different segmentation configurations (0.024 x 0.024; 0.033 x 0.028; 0.034 x 0.034). The results are attached below.

For those I haven't discussed this with before, we did this by scanning up and down the base of the lightguide with 1,000, 2.75 eV photons at each position -- distributed according to the exit characteristics of the scintillating fibers. The sipms are simulated by a series of scoring volumes at the end of the lightguide with the efficiency defined as the % events reaching the scoring volumes. The uniformity is the width of the efficiency distribution from each point along the scan.

Best,

Mike


 

_______________________________________________
Sphenix-emcal-l mailing list
Sphenix-emcal-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-emcal-l