Multichannel charge-coupled device

A transducer, such as a photomultiplier tube (or a multichannel charge-coupled device, CCD) that will convert the light intensity into electric current magnitude. 

In addition, with the tremendous improvements in multichannel charge-coupled device (CCD) detectors, high quality Raman data can be obtained efficiently. 

The main detectors used in AES today are photomultiplier tubes (PMTs), photodiode arrays (PDAs), charge-coupled devices (CCDs), and vidicons, image dissectors, and charge-injection detectors (CIDs). An innovative CCD detector for AES has been described [147]. New developments are the array detector AES. With modem multichannel echelle spectral analysers it is possible to analyse any luminous event (flash, spark, laser-induced plasma, discharge) instantly. Considering the complexity of emission spectra, the importance of spectral resolution cannot be overemphasised. Table 8.25 shows some typical spectral emission lines of some common elements. Atomic plasma emission sources can act as chromatographic detectors, e.g. GC-AED (see Chapter 4). 

DNA samples are introduced into the 96-capillary array. When the samples are separated through the capillaries, the fragments are irradiated with laser hght. A charge coupled device measures the fluorescence and acts as a multichannel detector. The bases are identifled in order in accordance to the time required for them to reach the laser-detector region. 

Optical spectroscopy ranging from Raman through Atomic is under considerable pressure to replace the "tried and true" photomultiplier tube (PMT) with multichannel devices. Two classes of solid state devices, the Charge Coupled Device (CCD) and the Charge Injection Device (CID), hold great promise for meeting this need. Operating modes of these devices are reviewed. Characteristics pertinent to analytical spectroscopy are presented. 

There are a number of different types of photon detectors, including the photomultiplier tube, the silicon photodiode, the photovoltaic cell, and a class of multichannel detectors called charge transfer devices. Charge transfer detectors include photodiode arrays, charge-coupled devices (CCDs), and charge-injection devices (ClDs). These detectors are used in the UV/VIS and IR regions for both atomic and molecular spectroscopy. 

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