Extremely sensitive radiation detectors to explore the universe

The Institute of Materials Science of Barcelona of the CSIC leads the development in Spain of a ultrasensitive sensors which will be used in the forthcoming European space missions. They are extremely sensitive and miniaturized microcalorimeters, like small thermometers, and can even detect the energy of one single photon. They find also applications in others fields, such as nanotechnology, biomedicine or security.

Wafer with TES sensors, at the ICMAB-CSIC.The team lead by Dr. Lourdes Fàbrega is the only one in Spain developing this type of sensors. The study is funded by the European Space Agency (ESA), H2020 Europe and Spain’s Space National Plan.


¿In which mission will they be used?

These sensors are being planned to be used as a European backup of the X-IFU instrument (high resolution X-ray spectrometer) in ESA’s X-ray telescope ATHENA, to be launched by 2030s. ATHENA (Advanced Telescope for High-ENergy Astrophysics) will substitute the successful XMM-Newton and will study the origin of the galaxies, black holes and other phenomena of the hot and energetic universe.

"This type of sensors is also being developed as an enabling technology, to be used in other space missions such as SPICA/SAFARI (SPace IR telescope for Cosmology and Astrophysics)”, says Dr. Fàbrega.

More details about these sensors

These sensors, called transition-edge-sensors (TES), are made out of molybdenum and gold (Mo/Au) bilayers, which have superconducting properties and work at cryogenic temperatures (100 mK). Other sensors like these ones can be made out of other materials, such as titanium and gold (Ti/Au).

Molybdenum is a superconducting material with a very small critical temperature (1K). The critical temperature is the temperature at which the resistance to electricity increases sharply. Combining molybdenum with a metal layer in close contact, such as gold, its critical temperature decreases down to 100 mK. These low temperatures are necessary to ensure the detection of radiation with high sensitivity and with low excess noise.

When coupled to a suitable absorber, TES sensors become radiation detectors with outstanding spectroscopic capabilities; this makes them extremely interesting for a variety of instruments which require high sensitivity and resolution.

Do TES have other applications?

TES cryogenic radiation detectors constitute the next generation in instrumentation for a variety of scientific and technological applications. They are already in use in a wide range of applications, including astronomy, nanotechnology, biomedicine, security and industry, due to their extraordinary sensitivity.

TES sensors are used for materials characterization, for instance, in synchrotron facilities. The Advanced Photon Source (Argonne National Laboratory), the EBIT (Lawrence Livermore National Laboratory) and the Brookhaven National Laboratory, all in the USA, use cryogenic TES sensors in their high-resolution X-ray spectrometer beam lines.

“With this study, we will enable Spain to have high value instrumentation, and we will enhance the electronic applications of superconducting materials”, says Dr. Fàbrega.

Other partners of this Project are the ICMA-CSIC (Institute of Materials Science of Aragon), the IFCA-CSIC (Instituto de Física de Cantabria) and the SRON-Netherlands Institute for Space Research, among others.

Article via ICMAB-CSIC

Video of the Athena mission: https://youtu.be/4GUfdbzJDJ0