Feb 08, 2024
Exotic, very neutron-rich nuclei: a laboratory for nuclear interactions
For the first time, an experiment has provided key observations on the spectroscopy of the neutron-rich unbound oxygen nuclei (proton number Z = 8), oxygen 28 (N = 20) and its neighboring isotope at N = 19, oxygen 27.
Jan 22, 2024
A comprehensive revision of the summation method lays new and solid foundations for the calculation of antineutrino spectra emitted by a nuclear reactor. This major advance sheds new light on the origin of the reactor antineutrino anomalies, and will be
Supported by CEA's "digital simulation" cross-disciplinary program, Irfu, the Laboratoire National Henri Becquerel of DRT and the Service d'Étude des Réacteurs et de Mathématiques Appliquées of DES teamed up to carry out a thorough review of calculations of antineutrino spectra from nuclear reactors.
May 30, 2023
The final piece of a longstanding adventure started in 2014 with an experiment led by Irfu and RIKEN Nishina Center has been set with the publication of a paper containing the comparative study of dineutron correlation in 11Li, 14Be and 17B [1]. This paper published in Phys. Lett.
Apr 13, 2023
Prediction of nuclear properties based on a realistic description of the strong interaction is the main quest of low-energy nuclear theory. One of the issues lies is the cost of solving Schrödinger’s equation that scales exponentially with the number of nucleons.
Nov 07, 2022
A new window into the deformation of nuclei has been recently opened with the realisation that nuclear collision experiments performed at high-energy colliders, such as the BNL Relativistic Heavy Ion Collider (RHIC) or the CERN Large Hadron Collider (LHC), give access to the shape of the colliding isotopes.
Oct 13, 2022
The pygmy dipole resonance (PDR) is a vibrational mode of the nucleus that occurs in neutron-rich nuclei. It is described as the oscillation of a neutron skin against a core symmetric in number of protons and neutrons (Figure 1). The PDR has been the subject of numerous studies, both experimental and theoretical.
Jun 24, 2021
DPhN physicists have played a decisive role in the first measurement of pairs of nucleons using a new method, that will pave the way to the study of short range interactions in radioactive nuclei.
Nucleons are social particles. Not only do they enjoy living in communities inside nuclei, but they also form couples within these communities. Indeed, one can observe protons and neutrons forming pairs inside nuclei.
Jun 04, 2021
Two state-of-the-art instruments, GLAD and COCOTIER, were designed and built at Irfu in the last few years and are now operational in the R3B experimental room of the GSI heavy ion accelerator (Darmstadt, Germany). Both are intended to be part of the equipment that will be used at FAIR, the new machine under construction at the GSI site.
May 19, 2021
IRFU engineers and physicists and their collaborators have just completed the development of a modern Sirius, a key element of the super spectrometer separator (S3) under construction at GANIL.
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.
Apr 14, 2021
Two “mirror” nuclei, in which the numbers of neutrons and protons are interchanged, have markedly different shapes—a finding that defies current nuclear theories.
Aug 20, 2020
The spectroscopy of a mendelevium isotope, 251Md composed of 101 protons and 150 neutrons, reveals a surprise: when it rotates, it behaves exactly like a lawrencium isotope made of 103 protons and 152 neutrons.
May 29, 2020
The simple question “Where does the Periodic Table end?” has excited scientific interest for a long time. In this context, understanding the structure of the heaviest nuclei, and through it their stability, is of major importance. A decade ago, there was no promising path to tackle this scientific quest.
Jun 07, 2019
Predicting properties of, e.g., molecules or atomic nuclei from first principles requires to solve the Schrödinger equation with high accuracy. The computing cost to find exact solutions of the Schrödinger equation scales exponentially with the number of particles constituting the system.
May 22, 2019
Pairing is ubiquitous in physics. From superconductivity to quantum shell structure, coupling particles into pairs is one of nature's preferred ways to lower the energy of a system.
May 02, 2019
An international collaboration led by the institutes of CEA-IRFU and of RIKEN (Japan) demonstrates, for the first time, the exceptional stability of the very-neutron rich nickel-78 nucleus and its doubly-magic character.
Jan 24, 2019
Prediction of nuclear properties based on a realistic description of the strong interaction is at the heart of the ab initio endeavor in low-energy nuclear theory. Ab initio calculations have long been limited to light nuclei or to nuclei with specific proton and neutron numbers.
Nov 20, 2018
During an experiment carried out at GANIL in Caen (France), an international team, led by researchers from Irfu and the University of Oslo, studied the shape of the Zirconium-98 nucleus. The shape of a nucleus corresponds to the area where its protons and neutrons can be found.
Sep 21, 2018
The first triplet of superconducting multipoles of the S3 Super Separator Spectrometer arrived at Ganil on August 29, 2018. S3 is one of the experiment rooms of the Spiral2 facility. The magnet, with a mass of 2.8 tonnes, is 1.8 m long and almost as high.
Feb 02, 2018
During an experiment carried out at the accelerator of the Australian National University (Canberra, Australia), a French-Australian collaboration (GANIL Caen, IPN Orsay, IRFU/DPhN Saclay, ANU Canberra) first identified the fragments created in quasi-fission reactions with atomic numbers Z up to plutonium (Z=94) and mass A.
Jun 14, 2017
An international team has performed the first spectroscopy of the very neutron-rich isotopes 98,100 Kr. The collaboration, led by scientists from the CEA Irfu and RIKEN (Japan)  included several European groups and physicists from IPN-Orsay.
Jan 24, 2017
An international team led by IRFU and the Japanese research institute RIKEN was able to study the structure of a neutron-rich zirconium nucleus (110Zr)—a first, calling certain models into question. Produced by an accelerator at RIKEN and measured by the MINOS detector, this heavy nucleus proves to be more deformed than expected. 
Aug 04, 2016
A comparison between experiment and theory on the ground state observables of the oxygen nuclei
The comparison of ab initio calculations and experimental data was the subject of original work initiated by physicists from the Nuclear Physics Department of the CEA-Saclay: for the first time, this study combines two types of fundamental observables of the nucleus: mass (binding energy of the fundamental state) and size in terms of nuclear radius, in the form of the mean square radius of the density of matter (all nucleons, protons and neutrons), and the proposed comparison is extended to the most neutron-rich isotopes.
Nov 02, 2015
The "exotic" nuclei pose the challenge of a universal description of the nuclear structure and raise the question of  the evolution of the shell structure. An IRFU team has developed the Magic Number Off Stability (MINOS) project to answer these questions.

 

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