Division of Electronics, Detectors and Computing for Physics (DEDIP)

The search for double beta decay without neutrino emission (0νββ) is one of the major challenges of contemporary physics, because its observation would make a clear statement about the nature of the neutrino itself and potentially on the origin of the matter/antimatter asymmetry of our universe. The CUPID collaboration, in which several researchers from IRFU and IN2P3 are involved, is actively researching this process using scintillating bolometers as detectors. In June 2020, the CUPID-Mo demonstrator experiment, which is located at the Modane underground laboratory, demonstrated the excellent potential of this detection method with only 2.264 kg of ¹⁰⁰Mo and one year of data collection. In the coming years, the objective of the CUPID collaboration is to design one of the most sensitive experiments ever built by increasing the total mass of ¹⁰⁰Mo to 250 kg. Three articles have just been published on the technological and methodological choices needed for this change of scale, while maintaining the required performances of the final experiment.

The ancients understood that heroes, like Orion with Sirius, need their faithful companion. IRFU engineers and physicists and their collaborators are no exception to the rule and have just completed the development of a modern Sirius, a key element of the super spectrometer separator (S³) under construction at GANIL. The tests having been successful and the system has been moved to GANIL for its final installation.

In Greek mythology, Sirius, Orion's faithful four-legged companion, an outstanding hunter, was transformed into a constellation and placed at his side. This famous canid also gave its name to the brightest star in the night sky. IRFU physicists have just honoured him in their own way, this time in the world of detectors.

An X-ray camera, intended to equip the Sino-French SVOM satellite, has just been assembled and delivered by scientists and technicians from the Institute for Research on the Fundamental Laws of the Universe (CEA/Irfu). This high-tech prototype will capture high-energy photons (X-rays) emitted during the explosion of massive stars or the fusion of dense stars. The camera, particularly compact and innovative, integrates in a very limited volume, a complete detection chain, an active thermal control and a filter wheel. It will be placed at the focus of a telescope 1.15 m long to form the MXT (Microchannel X-ray Telescope). With a field of view of 1 square degree, for only 35 kg of mass, the MXT telescope, equipped with an original "faceted" optics inspired by lobster eyes, will make it possible to locate the position of the most powerful cosmic explosions in the Universe with a precision better than 2 arcmin. After various tests, including a calibration campaign in Germany, the assembly will be shipped to China in November 2021 to be integrated into the SVOM satellite, which is scheduled for launch at the end of 2022.

See : Timelapse of the MXT camera assembling in cleanroom

On 29 August 2019, scientists from the H.E.S.S. collaboration recorded one of the brightest cosmic explosions ever observed in the Universe. This gamma-ray burst emitted the most energetic photons ever detected in this type of event. Under the direction of Irfu researchers, the observations continued for several days. The analysis of the data collected calls into question the origin of the rays produced during the explosion. These results has been published  by the international team, which includes researchers from CEA and CNRS, in the journal Science on 4 June 2021.

H.E.S.S., located in Namibia, is a system of five imaging atmospheric Cherenkov telescopes that has been studying cosmic rays since 2003. In 2016, the cameras of the first four telescopes were completely refurbished using state-of-the-art electronics and in particular the NECTAr readout chip designed by the the DEDIP/Irfu laboratory.

The analysis of this exceptional gamma-ray burst was led by a physicist from the DPHP/Irfu astroparticle group.