A talk at the TIPP conference going on now in the Photon Detector session. This one is presented by Razmik Mirzoyan of Max Planck Institute. It's a fascinating look at what can already be achieved now for the CTA effort, and a hint of what might be possible in the future simply based on existing technology.
The core people in the CTA are MAGIC, HESS and VERITAS collaborations. It is an initiative to buld the next generation of large ground-based gamma ray detector, with 10 times higher sensitivity. They want to study AGNs, Black holes, gamma ray burst, and galactic sources (pulsars, supernovae, etc. Energy range is from 10 GeV to 100 TeV. Try to answer long-standing question about origin of cosmic rays. Planning on ~100 telescope, 2-arrays (south and north pole).
3 types of telescopes are planned, Large: 23 m, midsize 12 m, and small 4-7 m diameter. Use standard PMTs and maybe SiPM.
PMTs mainly from Hamamatsu and Electron Tubes, with QE peaking around 35-40% at around 400 nm. He selected the 1.5" PMT and discussed at length the property of the PMTs from the two companies. These are the ones being considered for the CTA, I presumed, if not used already.