The next European cosmology mission starts construction
The space mission EUCLID, intended to map the universe in order to understand the influence of dark matter and dark energy, just passed the implementation phase. The EUCLID mission of the European Space Agency (ESA), involving scientists from CEA-IRFU, is to be launched in 2020 by a Soyuz Russian rocket. It aims to measure the position and shape of over a billion galaxies up to distances of ten billion light years. EUCLID was selected in 2011 as the second medium mission (M2) of the ESA "Cosmic Vision" ... More »
A new method for the reconstruction of the finest details
Using the latest data from the Planck and WMAP satellites, the laboratory CosmoStat (LCS) of CEA-IRFU just provides the most complete and accurate picture of the diffuse microwave background of the universe considered to be the primary light emitted at the beginning of the expansion. The new map of the diffuse background was built thanks to a new method of separating components called LGMCA particularly well suited to the separation of galactic foregrounds that blur the background image. Unlike previous results, ... More »
IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other ... More »
Clusters and superclusters billions of light-years away
An international team, including scientists from the Astrophysics Department-AIM and the Particle Physics Department of CEA-Irfu, has just used the Planck satellite to discover galaxy clusters with characteristics that were previously unknown. These clusters, which contain up to a thousand galaxies, are the largest structures in the Universe. Many of them are located very far away from us, and we still know relatively little about them. Astrophysicists were able to detect the new clusters thanks to the imprint left in ... More »
The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris). Read the joint press ... More »
The Double Chooz collaboration recently completed its neutrino detector which will see anti-neutrinos coming from the Chooz nuclear power plant in the French Ardennes. The experiment is now ready to take data in order to measure fundamental neutrino properties with important consequences for particle and astro-particle physics.             contacts:       Thierry LASSERRE Christian VEYSSIERE    
High field magnetic resonance imaging at field strengths at or above 7 tesla appears to be one of the most promising techniques for the early detection of neurological pathologies. Currently beyond the reach of most MRI system manufacturers, this imaging technology is beset with new technological difficulties. The CEA Iseult project team (IRFU and I2BM) has now overcome one of these problems; the homogeneous excitation of atomic nuclei using parallel transmission. This is needed in order to achieve a uniform excitation ... More »
The first lead-lead collision results have been published
After almost a year collecting data from proton-proton collisions, the LHC at CERN began the injection of lead ions at the beginning of November, with the first collisions obtained on November 8. The energy in the nucleon-nucleon center of mass is 2.76 TeV, around ten times greater than that achieved previously by the RHIC in Brookhaven USA. The first results from ALICE have been made available without delay.
A team of physicists, engineers and technicians from IRFU are developing a new generation of MicroMegas trackers. The planned Compass II experiment at CERN, together with the Clas12 experiment at the Jefferson Lab, will impose new operational constraints preventing the current generation of trackers from working with nominal performance. Tests on a new generation of detectors have been carried out using particle beams generated at CERN. These tests have achieved both of their objectives; a reduction of the ... More »
In August 2010 at CERN in Geneva, a team of physicists from SEDI and SPP working in collaboration with a group from ETH-Zurich obtained the first successful results from a MicroMegas detector operating in a time projection chamber filled with pure cryogenic argon at a temperature of 87.2 kelvin.       
    The instrument known as MUSETT1 detected its first heavy nuclei during a commissioning experiment that took place in early April 2010 at the GANIL2 accelerator in Caen. MUSETT was built for identifying very heavy elements: transfermium, which are the elements beyond fermium (Z=100).  Nuclear physicists are interested in these extreme state of matter for testing the theoretical models that describe the nuclei. Initial results obtained with MUSETT are highly satisfactory, providing very good ... More »
The giant gas ring in Leo, formed when two galaxies collided
An international team led by astrophysicists from the Lyon Observatory (CRAL, CNRS/INSU, Université Lyon 1) and the AIM laboratory (CEA-Irfu, CNRS, Université Paris 7) has just shed some light on the origins of the giant gas ring in Leo.  The astrophysicists were able to detect an optical counterpart to this cloud, which corresponds to stars in formation, using the Canada-France-Hawaii telescope (INSU-CNRS, CNRC, U. Hawaii). The scientists then carried out numerical simulations on the supercomputers ... More »
Supernovae will no longer escape from physicists!
The SNLS collaboration (Supernova Legacy Survey, at the Canada-France-Hawaii telescope) has just published a new method which allows the determination of the recession velocity of supernovae, those "standard candles" which have appeared in the universe throughout its history. The novelty of the method is its ability to study these cataclysmic explosions without needing to turn to spectroscopy, which requires too much observation time, even when using the planet's largest telescopes. The method relies solely on ... More »
High resolution mapping of the first light in the Universe
Following its launch on 14 May 2009, the Planck satellite [1] has been continually observing the celestial vault and has mapped the entire sky since 13 August to obtain the first very high resolution image of the dawn of the universe. The Planck satellite has just finished its first sky coverage. The preliminary images reveal undreamed of details of emissions of gas and dust in our own galaxy. Scientists from CEA-IRFU, as part of a broad international collaboration, are currently working on the extraction and ... More »
The LHC is about to start up for an initial two-year period of data acquisition which will produce a flow rate and volume of data among the largest that the man has ever needed to process. During recent tests under real conditions, the Paris region research grid (GRIF) was able to provide the required performance, allowing physicists to access reconstructed data only four hours after it had been recorded at CERN. In 2010, the volume of data to process will be 100 times larger. The teams from IRFU have ... More »
Forest fires are a constant danger, particularly for arid countries. They act as a brake on economic development and are a threat to environment, by the large scale release of greenhouse gases as well as by the destruction of ecosystems.   The FORFIRE project, which includes the use of Micromegas1 detectors, has been supported by the European Union (FP7 program) in order to develop a network of sensors sensitive to the light emitted during a forest fire, allowing its almost instantaneous detection ... More »
In Japan at the end of January 2010, the detectors of the Tokai to Superkamiokande (T2K, [ti:tu:kei]), developed at Saclay, observed their first neutrinos. These detectors consist of two large chambers where the tracks of charged particles are able to be reconstructed and the neutrino beam can be characterized. In this experiment, neutrinos are created by a proton beam coming from the Tokai accelerator. These same neutrinos are then measured 300 km away, at Kamioka, in a large water vessel 40 m in diameter and 40 m ... More »
The CHyMENE project (Cible d'Hydrogène Mince pour l'Etude des Noyaux Exotiques -Thin hydrogen target for the study of exotic nuclei) has the ambitious goal of producing a thin target of pure hydrogen, without using a container, suitable for experiments using the low-energy heavy ion beam planned for SPIRAL2.     A team from IRFU (SPhN and SACM) and from l'Inac/SBT have recently applied cryogenic techniques to successfully produce a ribbon of solid hydrogen 100 μm thick. The target will soon ... More »
Edelweiss-ID: innovative detectors for tracking dark matter in the Milky Way
  The new generation of detectors from the Edelweiss experiment, which is searching for dark matter, have just delivered their first results.  Remarkably reliable and robust, they have proved excellent at removing interference signals. Although only just installed and not yet perfected, these new detectors have improved the experiment's sensitivity by a factor of 10 in terms of its capacity to measure an interaction with a "wimp"1 , a weakly interacting massive particle, which is one of the candidates ... More »
    Engineers and physicists from IRFU have successfully assembled and commissioned three large chambers designed to reconstruct charged particle tracks. The chambers will characterize the neutrino beam used in the T2K (Tokai to Kamiokande) experiment. They are the first large Time Projection Chambers (TPCs) to be equipped with micromesh gas detectors (Micromegas). The chambers have a very large sensitive area (nearly 9m²) and a correspondingly high number of electronic channels (124,000). IRFU ... More »
A research team has just published the most precise measurement ever of the rate of gravitational collapse supernovae observed in the Universe 3.7 billion years ago
  The Supernova Legacy Survey (SNLS) team at the Canada-France-Hawaii Telescope facility has just obtained the world's best measurement of the explosion rate of massive stars when the Universe was only 10 billion years old. A research team at IRFU's particle physics department at the CEA-Saclay centre worked on the first three years of SNLS data to obtain this result, which makes a crucial contribution to our understanding of the origins and evolution of chemical elements in the interstellar medium. The ... More »
The second phase of the Double Chooz international experiment officially began on Wednesday 20 May. The Declaration of Intent signed by the four partners (CEA, CNRS, EDF, Champagne-Ardenne Region) is the first step in the plan to build a second detector devoted to neutrino research next to the Chooz nuclear power plant. Prior to signing the DOI, the participants visited the site of the first detector, currently under construction. By the end of the year, the detector should pick up the first neutrinos ... More »
At the end of March 2009, the ALICE Muon Spectrometer took cosmic rays over a period of two weeks. The ALICE group at Saclay2 was closely involved in the design, development, construction and installation of a part of the chambers of this Spectrometer3. The purpose of the cosmic ray test was to check the performance of the entire system, from acquisition to reconstruction of the data. The acquisition system readout about a million channels and the data was recorded on the computing grid. Almost 15,000 tracks were ... More »
Since researchers have been confronting the standard model of particle physics with experimentation, nothing has been able to shake it. Of all particles it describes, only the Higgs Boson has not yet been discovered. But the standard model is probably not the ultimate theory: it does not cover gravitation and numerous experimental observations remain unexplained. A new invariance, called supersymmetry, was suggested during the 1970s. It associates particles with different spins (integer spin bosons and ... More »
It has now been more than two years that Antares1, the underwater telescope installed in the depths of the abyssal plains 2500 m under the Mediterranean, is scanning the skies through the Earth in search of neutrinos. Over a thousand of them have already been observed until today, making it possible to establish the first views of the heavens to search for high-energy cosmic neutrinos, particles that may be able to teach us more about the most violent phenomena in the Universe.     Neutrinos are ... More »
    Until the advent of the LHC, the Tevatron at the Fermi National Accelerator Laboratory, Fermilab (close to Chicago, USA), will remain the world's most powerful collider and the only location where the top1 quark can be produced. The DØ experiment recently published2 results on the measurement of the rate of production of top-antitop quark pairs. This quantity, which is dependent on the value taken for the mass of the top quark, enables a prediction to be made for that mass using the standard ... More »
The Nobel Prize for Physics 2008 rewarded Makoto Kobayashi and Toshihide Maskawa for having realised that the weak interaction does not affect particles and antiparticles in the same way1. In this theory, it was expected that the strong interaction would exhibit the same type of asymmetry between quarks and antiquarks. However the asymmetry is not there! A problem! To explain this anomaly of the strong interaction, theoreticians have postulated the existence of a new particle known as the "axion", named after a ... More »
In collaboration with IRFU teams, CMS teams are currently making preparations for the first LHC data acquisition campaign.
On November 14, 2008, the Compact Muon Solenoid (CMS) successfully generated a nominal magnetic field of 4 tesla. This success rewards IRFU efforts for the design and construction of what constitutes the largest superconducting solenoid magnet in the world. Over a period of approximately one month, CMS teams conducted a continuous data acquisition campaign with the detector operating under nominal conditions. Approximately 300 million cosmic events were recorded. This also provided an excellent opportunity to showcase ... More »
Jean-Luc Starck, an experienced research scientist at IRFU (the CEA Institute for Research on the Fundamental Laws of the Universe) was awarded a 2.2 million euro grant spread over five years under the 7th European research and development framework programme (FP7). The grant comes in recognition of Mr Starck's research project in statistics, signal and image processing and its applications to astrophysics.
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