The main reasons why strong light can damage photomultiplier tubes can be summarized as follows:

1. Overheating and evaporation of photoelectric emission materials

When the incident light intensity is too high or the irradiation time is too long, the photocurrent inside the photomultiplier tube will significantly increase. This will cause the temperature of the electrodes (especially the photocathode and multiplier) of the photomultiplier tube to rise.
High temperatures can cause excessive evaporation of photoemissive materials (such as those on the photocathode), thereby reducing the amount of material available for photoelectric conversion, thereby reducing the sensitivity and performance of photomultiplier tubes.

2. Fatigue effect of photomultiplier tubes

Long term high-intensity light exposure can also cause fatigue effects in photomultiplier tubes, manifested as attenuation of photocurrent and sudden decrease in sensitivity.
The fatigue effect is caused by excessive photocurrent leading to a decrease in the performance of electrode materials, which in turn affects the overall performance of photomultiplier tubes. This effect may partially recover after a period of rest, but long-term accumulation can lead to permanent damage to the photomultiplier tube.

3. Design and working principle limitations of photomultiplier tubes

Photomultiplier tube is an electronic vacuum device based on the external photoelectric effect and secondary electron emission effect, and its working principle determines that it is very sensitive to light signals.
However, this high sensitivity also means that it is more susceptible to the influence of strong light. When the incident light intensity is too high, the photomultiplier tube may not be able to effectively process such a large amount of light signals, resulting in excessive internal current and damage to the device.

4. Precautions in practical applications

When using photomultiplier tubes, strong light should be avoided from directly shining on the device. Especially when working with high voltage in photomultiplier tubes, attention should be paid to avoiding interference from external light sources.



In addition, it is also necessary to pay attention to maintaining a suitable working environment temperature for the photomultiplier tube to avoid adverse effects of high or low temperatures on its performance.

The main reasons why strong light can damage the photomultiplier tube are the overheating and evaporation of the photoelectric emission material, the fatigue effect of the photomultiplier tube, the design and working principle limitations of the photomultiplier tube, and improper operation in practical applications. Therefore, when using photomultiplier tubes, special attention should be paid to avoiding strong light exposure and maintaining suitable working environment conditions.