What is a photomultiplier tube (PMT) used for?

A photomultiplier tube (PMT) is specifically designed for detecting low levels of light and amplifying the resulting signal. When photons hit the photocathode of the PMT, they are converted into electrons. These electrons are then amplified through a series of dynodes, allowing the PMT to detect very weak light signals even in dark environments. This capability is crucial in various applications such as nuclear and particle physics, medical imaging, and analytical chemistry, where precise detection of light is needed.

The other options do not precisely describe the function of a PMT. While amplifying electrical signals might be a general attribute of electronic devices, it does not capture the specific function of light detection and amplification that a PMT performs. A digital signal processor focuses on processing digital data, which is unrelated to the primary function of the PMT. Similarly, while generating electrical energy from photons pertains to photovoltaic cells, PMTs do not generate energy; rather, they detect and amplify light signals, making option C the most accurate choice.