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photocathode
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Figure 8: Image orthicon camera tube.
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Related Topics:
photoelectric cell
cathode
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photocathode

electronics
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History

photocathode, an element of a photoelectric cell (q.v.) that emits electrons when struck by light, making possible the flow of electric current through the device. A substance often used for photocathodes is a partially oxidized silverā€“cesium alloy.