Lourdes Fàbrega

Cryogenic radiation detectors based on superconductors: forefront technology for Big Science, Space, Materials and Quantum Communications.

Field of interest:

We develop microcalorimeters and bolometers based on superconductors, the so-called Transition-Edge Sensors (TES), operating below 1K. The low temperatures and the use of superconductivity (typical excitations 3 orders of magnitude below those in semiconductors) allow single photon detection combined with spectroscopic capabilities, low dark count rates and excellent sensitivity with high efficiency, over a wide energy range.

Because of their performances, TESs have found applications in revolutionary instruments for cosmology and astrophysics, in Space, on ground and underground: a most remarkable example is X-IFU, the high resolution spectrometer on board Athena, ESA’s next X-ray telescope. Also, TES detectors are in use as high resolution spectrometers in several beam lines and accelerators for materials science; due to their sensitivity, they are particularly suited for systems requiring low dose as biological, or very delicate, or techniques or materials with low efficiency photons generation: characterization of impurities, X-ray Raman Scattering, PIXE, … as well as to identify traces of nuclear materials. Finally, TES detectors are also interesting for satellite and quantum communications, because of their photon counting capabilities.

Currently, our work focuses on X-ray detectors for high resolution spectrometers (single pixels can achieve energy resolution of 2eV @6keV, with single photon detection). We are also interested in accessing other energy ranges and broadening the span of applications of TES. Planned or under study activities are related to axion search, and NIR-VIS-UV sensors, with interest in astronomy, space exploration and quantum communications. Collaborations to develop multiplexed readouts of arrays are sought.

Capabilities:

ICMAB and collaborators can fabricate, simulate and test TES detectors. They possess or have access to the required equipments, which include clean room facilities, electrodeposition setups and dilution refrigerators. We accumulate expertise in superconductivity, superconducting devices and detectors, cryogenics and cold electronics.