Teamworking towards next generation telescopes

Watch as Kenichiro Nagayoshi and Marcel Ridder and their colleagues make detectors for the Athena X-ray telescope.

In 2031, ESA launches its new X-ray telescope Athena. SRON plays a major role in building one of the two instruments, the X-IFU spectrometer, by developing the X-IFU camera plus the back-up detectors.

From an orbit around the Sun, one and a half million kilometres behind the Earth, Athena will map the hot gas structures in the universe and study the evolution of super-heavy black holes. To do this, Athena will have to measure energy spectra with unprecedented resolution.

Developing the TES detectors

The telescope uses superconductive Transition Edge Sensors (TES) that operate at a temperature of 50 mK – fifty thousandth of a degree above absolute zero – to determine the energy of individual photons.
When a photon hits a sensor, it heats up a little, proportional to the energy of the photon. This reduces the superconductive state and the camera reads a smaller current than normal, providing the necessary information.

Kenichiro Nagayoshi and Marcel Ridder made this video about how TES detectors are made at SRON. You first see them ‘made of cardboard’, but then how they are made on a nanoscale in the cleanroom.


With the development of the TES for a reading system based on Frequency Domain Multiplexing, SRON researchers have set a new world record in the energy spectrum around 6 keV, with a resolution of 1.3 eV. This is the result of intensive research into the physics behind the detector, led by Luciano Gottardi (SRON) in collaboration with colleagues from NASA-Goddard.
Key roles were played by Kenichiro Nagayoshi, who manufactured the lithographic devices, Martin de Wit and Emanuele Taralli, who adapted the hardware for each round of tests and carried out the tests, and Marcel Ridder, who played a crucial role in the clean room. They are supported by the rest of the SRON team, coordinated by Jian-Rong Gao.

Building the camera

That typical teamwork example is only about TES detectors. But in the meantime another multidisciplinary team at SRON is building the X-IFU camera of which TES detectors are the main focus. It’s not just at SRON that disciplines work together. X-IFU – just like the Athena telescope on which the instrument will be installed – will be the result of international collaboration between high-quality knowledge institutes around the world. This film is all about X-IFU.


Scientifically driven

All this technological development work is driven by the scientific questions about the universe that remain unanswered. Astrophysicists at SRON are pre-eminently scientists who not only look at telescopes, but are also concerned with the question of what a next generation of telescopes must be able to do in order to keep moving forward.