Photomultiplier Tube Power Supply, -2000 V, Ultrastable

The 70706 Photomultiplier Power Supply provides the highly regulated voltage needed for precision measurements with Oriel photomultiplier tubes (PMTs). Since the signal current varies as the 5th to 10th power of the supply voltage (depending on the PMT), stability of the voltage supply is vital. It is used to supply negative voltages to -2000 V, and has a positive ground. This facilitates connection of the output (anode) to our current measuring equipment. The 70706 Power Supply has an LED digital display and two high voltage BNC outputs for photomultiplier tubes. Since both outputs are on the same power supply, this ensures that two similar PMTs can be operated with a minimum of independent drift. This can be critical when one PMT is monitoring a reference light beam, for instance, while the other is measuring the sample signal. The 70706 provides the ability to control output voltages, both the value (0 to 9 V analog input) and ON/OFF. The ON/OFF feature can be used for an interlock function, for operator safety, and/or to protect the PMT from excess light such as may occur when changing samples.