Laboratory link : http://irfu.cea.fr/dap/
The Herschel submillimeter space observatory has revolutionized some areas of astrophysics, such as star formation, showing that stars are formed mainly in filaments of gas and dust. This rises a fundamental question on the role of the magnetic field within these structures that cannot be solved by the current astrophysical instruments. The B-BOP instrument, installed on the future SPICA international space observatory and proposed by CEA Saclay, will be able to detect a wide variety of far-infrared filaments, as well as their possible associated magnetic field (through the polarization of the light coming from these regions).
B-BOP will contain 3 focal planes of cryogenic silicon bolometers currently developed by CEA (LETI and Saclay). These are very innovative detectors, operating at 50 mK, with a very high sensitivity. Each pixel is intrinsically sensitive to the polarization of incident radiation.
For this thesis, the first step will be to model, and test the bolometers of Safari-Pol (measurement of sensitivity, time constant, cross-polarization, etc ...). This work will require the development of dedicated state-of-the-art instrumentation (very low flux optical sources, ultra low temperature cryostat). The results obtained will then be discussed in the more general framework of the instrument's preparation, in particular concerning its calibration, the estimation of its performance in space, as well as the optimization of future observation modes.