What is the typical voltage range applied to a photomultiplier tube (PMT)?

The typical voltage range applied to a photomultiplier tube (PMT) is indeed between 800 and 2000 Volts. PMTs are critical components in many imaging systems, including positron emission tomography (PET), as they convert incoming photons into electrical signals.

The high voltage is necessary to create a strong electric field within the PMT, which is crucial for the amplification process. When a photon hits the photocathode of the PMT, it generates photoelectrons. These electrons are then accelerated and multiplied through a series of dynodes, with the high voltage facilitating this acceleration and enhancing the overall gain of the PMT. By operating in the range of 800 to 2000 Volts, the PMT can effectively detect low levels of light, which is essential for accurate imaging in PET systems.

Lower voltage ranges, such as those under 800 Volts, may not provide sufficient electron acceleration for effective signal amplification, while values exceeding 2000 Volts could lead to issues such as increased noise and potential breakdown of the tube, which would negatively affect performance. Therefore, the specified range of 800 to 2000 Volts is optimal for achieving the balance needed for sensitive and reliable detection in various applications.