Gain Stabilization of SiPMs

The gain G of SiPMs depends both on bias voltage and on temperature. For stable operation in large detector systems, gain needs to be kept constant. This can be achieved by readjusting the bias voltage with temperature. We have built an adaptive bias voltage regulator (ADApower) that uses a linear algorithm to adjust the bias voltage V if the temperature T changes. We determined the V(T) dependence from measurements of the gain-versus-temperature dependence (dG/dT) for different bias voltage and the gain-versus-bias voltage dependence (dG/dV) for different temperatures in a climate chamber Spiral3 at CERN. We tested and studied 30 pieces of SiPM in groups of six types in temperature range of 5 to 40 degrees C and found that the gain stabilization works excellently (<1%).