H7844

The H7844 is a photosensor module consisting of a newly developed high sensitivity side-on photomultiplier tube, a high-voltage power supply circuit and a thermoelectric cooler. Cooling is super-efficient in the H7844 because the thermoelectric cooler is directly coupled to the photocathode of the photomultiplier tube. This also drastically reduces thermal noise (thermal electrons) emitted from the photocathode to allow making accurate measurements with a high signal to noise ratio even at very low light levels. As a result of cooling, dark current reduces down to 1/50 at room temperature after only 3 minutes of cooling.

Besides shorter cooling time and lower power consumption compared to conventional methods that cool the entire photomultiplier tube, the H7844 completely eliminates the problem of condensation during cooling.