To solve the problem of continuous decrease in photon quantity in photomultiplier tubes, the following aspects can be considered and operated on:



1. Check and replace the photocathode:
The photocathode is a crucial part of a photomultiplier tube that converts light signals into electrical signals. If the photocathode material ages, the photoelectron emission efficiency will decrease.
Solution: Regularly inspect and replace the photocathode to ensure its performance is in optimal condition.
2. Maintenance and cleaning multiplier:
The multiplier electrode in a photomultiplier tube is responsible for amplifying primary photoelectrons through secondary electron emission effects. If the performance of the doubling electrode material decreases, the amplification efficiency will decrease.
Solution: Regularly clean and maintain the multiplier to prevent contamination or physical damage from affecting its performance.
3. Control environmental conditions:
Environmental conditions such as temperature, humidity, and magnetic field can all affect the performance of photomultiplier tubes.
Solution: Control the laboratory environmental conditions, such as maintaining appropriate temperature and humidity, to avoid strong magnetic field interference.
4. Clean the optical path and incident window:
If the incident window or optical path of the photomultiplier tube is contaminated, it will reduce the transmittance of the light signal.
Solution: Regularly clean the incident window and check the cleanliness of the optical path to ensure efficient transmission of optical signals.
5. Check the power supply and voltage:
The photomultiplier tube requires a stable power supply and precise voltage to ensure its normal operation. Voltage fluctuations or instability may lead to gain instability.
Solution: Use a stable power supply and precise voltage regulation equipment to ensure that the photomultiplier tube can function properly.



6. Avoid prolonged high-intensity exposure:
Long term or high-intensity light irradiation may cause fatigue of the photomultiplier tube, resulting in a temporary decrease in sensitivity.
Solution: Avoid prolonged high-intensity exposure or use appropriate light attenuators to reduce fatigue.
7. Replace the photomultiplier tube:
If the sensitivity of the photocathode surface is uneven or there are other irreparable issues, the entire photomultiplier tube may need to be replaced.
8. Reduce dark current:
The increase of dark current will reduce the signal-to-noise ratio and affect the detection efficiency of photons.
Solution: Reduce dark current by lowering ambient temperature, reducing thermal radiation, and using dark current compensation technology.
9. Optimize spectral characteristics:
The spectral characteristics of photomultiplier tubes determine their ability to respond to light signals of different wavelengths. If the spectral characteristics change, it may affect the detection efficiency of photons.



Solution: Select photomultiplier tubes with appropriate spectral characteristics according to actual needs, or use other technical means to optimize spectral characteristics.
By comprehensively considering the above factors and taking corresponding measures, the problem of continuous decrease in photon quantity of photomultiplier tubes can be effectively solved, and their performance and stability can be improved.