QUBIC: Exploring the Primordial Universe with the Q&U Bolometric Interferometer

In this paper, we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control typical of interferometers. QUBIC’s unique features are the so-called “self-calibration”, a technique that allows us to clean the measured data from instrumental effects, and its spectral imaging power, i.e., the ability to separate the signal into various sub-bands within each frequency band. QUBIC will observe the sky in two main frequency bands: 150 GHz and 220 GHz. A technological demonstrator is currently under testing and will be deployed in Argentina during 2019, while the final instrument is expected to be installed during 2020.

Low background techniques in bolometers for double-beta decay search

Bolometers are low temperature particle detectors with high energy resolution and detection efficiency. Some types of bolometric detectors are also able to perform an efficient particle identification. A wide variety of radiopure dielectric and diamagnetic materials makes the bolometric technique favorable for applications in astroparticle physics. In particular, thanks to their superior performance, bolometers play an important role in the worldwide efforts on searches for neutrinoless double-beta decay. Such experiments strongly require an extremely low level of the backgrounds that can easily mimic the process searched for. Here, we overview recent progress in the development of low background techniques for bolometric double-beta decay searches.

Electromagnetic Optimization Of Ultra-Thin Resonant Absorbers For Bolometric Detectors Of The Submillimeter-Wave Range

We present the results of theoretical analysis and characteristics optimization for ultra-thin resonant absorbers based on artificial impedance surfaces, which are promising for using as the radiation-sensitive layers in selective bolometric detectors operating in the range of submillimeter waves. The key parameters of the ultra-thin absorbers, such as the absorption resonance Q-factor, the ratio of the peak absorptivity wavelength to the absorber thickness and the impedance surface unit cell size, are traced versus a geometric shape of the resonant elements and their electrical conductivity.