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

The ScanPyramids collaboration has discovered a new void in the heart of the Kheops pyramid. This large vacuum was detected by muonic imaging techniques conducted by three separate teams from Nagoya University (Japan), CEC (Japan) and CEA/IRFU. It is the first discovery of a major internal structure of Kheops since the Middle Ages.

Similar in size to the Great Gallery, an architectural structure located in the heart of the Great Pyramid (47m long, 8m high), this new cavity, called ScanPyramids Big Void, has a minimum length of 30 metres. First observed with nuclear emulsion films installed in the Queen's Chamber (Nagoya University), then detected with a scintillator telescope installed in the same chamber (KEK), it was confirmed with gas detectors, MICROMEGAS, located outside the pyramid (CEA), and thus with a very different angle of view allowing to refine the location of this void. This is the first time that an instrument has detected a cavity located at the bottom of a pyramid from the outside.

These results were published by the ScanPyramids team on November 2, 2017 in the journal Nature.

The Dark Energy Spectroscopic Instrument (Desi) will analyze the light emitted by 35 million galaxies and quasars at various times in the past of the Universe and up to 11 billion years to better understand dark energy. Its move into the construction phase in 2016 crowns several years of research and development that have resulted in a solid design and a credible observation strategy. Irfu, a partner in the project from the outset, has played a key role. A look back at a year that saw the project become a reality.

A new phase begins for DESI

For more than 10 years now, Irfu physicists and engineers have been developing in Saclay the necessary equipment for the GBAR experiment, designed to test the behaviour of antimatter under terrestrial gravity. An important step has just been taken with the installation at the Cern of a new positron source using on an electron linac, and the transport to the Cern of the positron trapping system built at Saclay.

The new source produced its first positrons on November 17, 2017. The installation of the traps is in progress, to be operational when the antiprotons arrive, scheduled for spring 2018.

The new-generation liquid argon detector used in the WA105 experiment at CERN has collected its first signals. This prototype is used in preparation of the Deep Underground Neutrino Experiment (DUNE) for neutrino observations on a mass scale, which is due to start in 2026 in the USA. This research involving IRFU aims, in particular, to shed light on the origin of matter and antimatter.