The main reasons why photomultiplier tubes in photon counters work in low-temperature environments are as follows:
Improve doubling efficiency and counting efficiency:
The electron multiplication process in photomultiplier tubes is based on the secondary emission effect, where the higher the electron emission energy, the lower the multiplication and counting efficiency.
Lowering the temperature in a photomultiplier tube can reduce the thermal energy of electrons, increase the energy of emitted electrons, and thus improve the efficiency of multiplication and counting.

Reduce the generation of stray electrons:
In low-temperature environments, the number of stray electrons in photomultiplier tubes decreases, which helps to reduce the interference of stray electrons and improve the performance stability and measurement accuracy of photon counters.



Optimize the electronic amplification process:
In low-temperature environments, the internal electron amplification process of PMT (photomultiplier tube) may be affected by temperature. An appropriate low-temperature environment can reduce traps and scattering during electron amplification, thereby improving amplification gain.

Reduce noise levels:
Low temperature environment can reduce the noise level caused by changes in the dynamic characteristics of electrons, and improve the reliability and accuracy of signals.
Enhanced temperature stability:
The performance and operating point of PMT usually vary with temperature changes. In low-temperature environments, higher temperature stability can be achieved by optimizing the structural design and temperature control system of PMT.



The operation of photomultiplier tubes in photon counters in low-temperature environments can significantly improve the multiplication efficiency and counting efficiency, reduce the interference of stray electrons, optimize the electron amplification process, reduce noise levels, and enhance temperature stability. These advantages collectively enhance the overall performance and measurement accuracy of photon counters. However, it should be noted that low-temperature environments may also bring some challenges, such as the need to strengthen gas compensation and control, remove and monitor hydrides, etc., to ensure the normal operation and stable performance of photomultiplier tubes.