Complementary Measurement of Thermal Architecture of NbSi TES with Alpha Particle and Complex Impedance
Abstract
As shown by the Planck mission (Planck Collaboration. Astronomy and astrophysics. arXiv1303.5071P, 2013), background limited bolometers in a space environment are very sensitive to high energy particles. In order to not degrade their sensitivity, it is necessary to reduce this unwanted signal. To achieve this goal, a good understanding of the detector's thermal architecture is mandatory. To investigate this question, we used an particle source in front of our niobium silicon (NbSi) alloy Transition edge sensors (TES). The number of time constants required to fit the data and the way these time constants behave as we change the bias power gave us a good insight on the TES thermal architecture. Indeed we expect a decrease of the detector time constant due to the electro-thermal feedback properties. We will first present some standard characterizations of NbSi TES using a simple thermal model and how they indicate the presence of multiple thermal decouplings. Then we will show the results of the particles measurements and how we used them to build our thermal model for Complex Impedance fitting. All this work has been done for the QUBIC experiment, a B-modes instrument.