A Peltier cooling system for SiPM temperature stabilization

In the course of this thesis the basis for an automatic temperature stabilization system for silicon photomultipliers (SiPMs) based on Peltier elements was devel- oped and tested. The basic idea is to embed an SiPM and a monitoring temper- ature sensor into one side of a small body of copper which is thermally insulated from the outside and attached to a Peltier element. To automate the system, the temperature sensor and the Peltier element’s current supply are connected to a microcontroller board running a PID controller algorithm to adjust the current flow. For this purpose a Peltier driver board was designed to alter direct currents between 0 A and approximately 5 A in 16 steps controlled by the microcontroller. Besides testing the performance of the used setup in terms of achievable temper- atures, cooling rates etc., experiments with changes of the controller’s parameters wereconductedtoexamineifandhowatemperaturestabilizationcanbeachieved. Furthermore a series of measurement with different approached temperatures but fixed PID parameters were done to analyze in which region the stabilization sys- tem can be used. It was shown that the developed system can achieve temperature stabilization with maximum deviations of ±0.14 K between measured and desired temperature over several minutes between the given ambient temperature and roughly 25 K below. The time it takes to stabilize a temperature amounts to a few minutes and depends on how low it lies beneath the room temperature.