Optical Detector 2

These are the specifications of the Photomultiplier Tube (PMT) system used for the detection of fast laser beacon pulses. The head contains an integral pulse discriminator and pulse-stretcher.

Hamamatsu PMT Photon-Counter, Type HC4730-01

Type: Side Window

Photocathode Area: 4 x 20 mm²

Wavelength Range: 185 nm to 850 nm

Peak Quantum Efficiency (at 440 nm): 22%

Dark Count (at 25 C): 80 cps

Maximum Pulse Detection Rate: 3 Mcps

Pulse Rise-Time: 2 ns

Pulse Pair Resolution: 50 ns

Photon-Counter Output: BNC, 50 Ohm, TTL, 30 ns Pulse Width

Maximum PMT Supply Voltage: +1,250 V dc

Voltage Divider Current (at 1,000 V): 0.4 mA

Power Supply: +6 V dc, 200 mA; -6 V dc 100 mA

High-Voltage Power Supply Module, Type C4710-52

Input Voltage: +24 V dc

Output Voltage: +240 V to +1,500 V

Maximum Load Current: 1 mA

Material taken from word viewgraph 9308-005

ETI Photonics gratefully acknowledges Hamamatsu's donation of the above items to NAAPO (North American AstroPhysical Observatory) and The Columbus Optical SETI Observatory.