This interactive tutorial explores the interaction of photons with silicon as a function of wavelength. Photomultiplier Tubes - Photomultiplier tubes, useful for light detection of very weak signals, are photoemissive devices in which the absorption of a photon results in the emission of an electron. These detectors work by amplifying the electrons generated by a photocathode exposed to a photon flux. Explore electron amplification in photomultiplier tubes with this interactive Flash tutorial. Channel Photomultipliers - Channel photomultipliers represent a new design that incorporates a unique detector having a semitransparent photocathode deposited onto the inner surface of the entrance window.
Photoelectrons released by the photocathode enter a narrow and curved semiconductive channel.
Each time an electron impacts the inner wall of the channel, multiple secondary electrons are emitted. The effect occurs repeatedly, leading to an avalanche effect, with a gain exceeding 100 million. In the side-on photomultiplier tube design, photons impact an internal photocathode and eject electrons from the front face. Contributing Authors Mortimer Abramowitz - Olympus America, Inc., Two Corporate Center Drive., Melville, New York, 11747. Kenneth R. Spring - Scientific Consultant, Lusby, Maryland, 20657.