Correlated avalanches in Transition Edge Sensor noise power spectra

The peaked structures of the excess noise observed in many superconducting transition edge sensors are analyzed in both the normalized resistance and the frequency domains. In the framework of our dynamical percolation model we find high amplitude noise peaks in the low normalized resistance range (0.2 approximately) and of much lower amplitude in the high normalized resistance range (0.8), but no peaks are obtained in the power noise spectra in the very wide frequency range explored. The excess noise peaks experimentally explored are accounted for quantitatively by our statistical model of correlated avalanches. Our preliminary experimental noise results on a Ir thin film sensor are compared with literature results.