On Fri, Feb 14, 2014 at 7:45 AM, J. Forster <j...@quikus.com> wrote: > You should not denigrate PhotoMultiplier tubes. > > They are virtually perfect, almost noiseless, detectors. With the right > photocathode, they are capable of QEs >50%, spectral response from the VUV > to near IR, and dark counts <1 PPS, with maximum count rates >10 MPPS. > Thay can easily have current gains of >10E+6 >
Really? I used to work on photon-counting systems for photometric astronomy. As I recall, the best quantum efficiency I had ever seen was around 21%. Which cathode material are you talking about? Conversely I remember working on current amps for photodiodes. The photodiodes I was playing with had QEs of 90% but, of course, they had no current gain. Detecting individual photoelectrons is a challenge. Yeah, PM tubes are very cool devices, especially if you cool them to reduce the emission of thermal electrons. ;-) -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.