Publications associées à The beam lines design for the CERN neutrino platform in the CERN north area and an outlook on their expected performance

Wave-momentum shaping for moving objects in heterogeneous and dynamic media

Stefan Rotter, Romain Christophe Rémy Fleury, Bakhtiyar Orazbayev, Matthieu Francis Malléjac

Light and sound waves can move objects through the transfer of linear or angular momentum, which has led to the development of optical and acoustic tweezers, with applications ranging from biomedical engineering to quantum optics. Although impressive manip ...

2024

Design of a Flexure-Based Flywheel for the Storage of Angular Momentum and Kinetic Energy

Simon Nessim Henein, Florent Cosandier, Patrick Robert Flückiger, Hubert Pierre-Marie Benoît Schneegans

The flywheel is a widespread mechanical component used for the storage of kinetic energy and angular momentum. It typically consists of cylindrical inertia rotating about its axis on rolling bearings, which involves undesired friction, lubrication, and wea ...

2024

Single-shot Kramers-Kronig complex orbital angular momentum spectrum retrieval

Camille Sophie Brès, Jianqi Hu, Yujie Chen

Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverse OAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve the amplitude and phase information of complex OAM spectra in a few s ...

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS2023

Improved calorimetric particle identification in NA62 using machine learning techniques

Alessandro Mapelli, Radoslav Marchevski, Alina Kleimenova

Measurement of the ultra-rare K+ -> pi(+)nu(nu) over bar over bar decay at the NA62 experiment at CERN requires high-performance particle identification to distinguish muons from pions. Calorimetric identification currently in use, based on a boosted decis ...

Springer Nature2023

Generation of OAM-carrying space-time wave packets with time-dependent beam radii using a coherent combination of multiple LG modes on multiple frequencies

Tobias Kippenberg, Hao Song, Maxim Karpov, Zhe Zhao, Xinzhou Su

Space-time (ST) wave packets, in which spatial and temporal characteristics are coupled, have gained attention due to their unique propagation characteristics, such as propagation invariance and tunable group velocity in addition to their potential ability ...

Optica Publishing Group2022

Hard X-ray helical dichroism of disordered molecular media

Majed Chergui, Jérôme Lacour, Christian David, Giulia Fulvia Mancini, Malte Oppermann, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak sig ...

Nature Publishing Group2022

Experimental demonstration of dynamic spatiotemporal structured beams that simultaneously exhibit two orbital angular momenta by combining multiple frequency lines, each carrying multiple Laguerre-Gaussian modes

Tobias Kippenberg, Hao Song, Maxim Karpov, Zhe Zhao, Xinzhou Su

In general, there are different, relatively independent forms of orbital angular momenta at a given propagation distance, which might exhibit different dynamic spatial characteristics. One type involves a beam with a helical phase-front that rotates around ...

Optica Publishing Group2022

Quantum Circuits for the Preparation of Spin Eigenfunctions on Quantum Computers

Alessandro Carbone

The application of quantum algorithms to the study of many-particle quantum systems requires the ability to prepare wave functions that are relevant in the behavior of the system under study. Hamiltonian symmetries are important instruments used to classif ...

MDPI2022

Development of a novel two-phase flow solver for nuclear reactor analysis: algorithms, verification and implementation in OpenFOAM

Andreas Pautz, Stefan Radman, Carlo Fiorina

A porous medium-based representation of nuclear reactors and complex engineering systems more in general can significantly reduce simulation and modelling costs, while preserving a reasonable degree of accuracy via regime map-based correlations for modelli ...

2021

Tomographic reconstruction of the runaway distribution function in TCV using multispectral synchrotron images

Basil Duval, Joan Decker, Umar Sheikh, Gergely Papp, Artur Perek

Synchrotron radiation observed in a quiescent Tokamak a Configuration Variable (TCV) runaway discharge is studied using filtered camera images targeting three distinct wavelength intervals. Through the tomographic simultaneous algebraic reconstruction tech ...

IOP Publishing Ltd2021

Evidence of a coupled electron-phonon liquid in NbGe2

Mathieu François Padlewski, Philip Johannes Walter Moll, Matthias Carsten Putzke, Hao Yang

Whereas electron-phonon scattering relaxes the electron's momentum in metals, a perpetual exchange of momentum between phonons and electrons may conserve total momentum and lead to a coupled electron-phonon liquid. Such a phase of matter could be a platfor ...

Nature Portfolio2021

Multipolar origin of electromagnetic transverse force resulting from TE/TM wave interference

Olivier Martin, Karim Achouri, Andrei Kiselev

In this paper, we aim at unveiling the underlying physical mechanism for transversal optical forces, appearing due to the simultaneous illumination of a spherical object with two plane waves possessing different polarizations. The appearance of such a tran ...

2021

Moment approach of the multi-species non-linear Coulomb collision operator adapted to particle-in-cell codes

Stephan Brunner, Laurent Villard, Emmanuel Lanti, Noé Thomas Elie Ohana, Moahan Murugappan, Claudio Gheller

In this article an approximated version of the multi-species, non-linear Coulomb collision operator is derived via the use of a truncated moment expansion of the distribution function to compute the Rosenbluth potentials. The evolution of the distribution ...

2021

Shapes of rotating normal fluid He-3 versus superfluid He-4 droplets in molecular beams

Andre Al Haddad, Christoph Bostedt

Previous single-pulse extreme ultraviolet and x-ray coherent diffraction studies revealed that superfluid He-4 droplets obtained in a free jet expansion acquire sizable angular momentum, resulting in significant centrifugal distortion. Similar experiments ...

AMER PHYSICAL SOC2020

Momentum space CFT correlators for Hamiltonian truncation

Matthew Thomas Walters

We consider Lorentzian CFT Wightman functions in momentum space. In particular, we derive a set of reference formulas for computing two- and three-point functions, restricting our attention to three-point functions where the middle operator (corresponding ...

Springer Nature2020

A stability theory beyond the co-rotational setting for critical wave maps blow up

Joachim Krieger, Shuang Miao

We exhibit non-equivariant perturbations of the blowup solutions constructed in [18] for energy critical wave maps into

\mathbb{S}^2

. Our admissible class of perturbations is an open set in some sufficiently smooth topology and vanishes near the light co ...

2020

Spatio-temporal shaping of a free-electron wave function via coherent light-electron interaction

Fabrizio Carbone, Ivan Madan, Giovanni Maria Vanacore

The past decade has witnessed a quantum revolution in the field of computation, communication and materials investigation. A similar revolution is also occurring for free-electron based techniques, where the classical treatment of a free electron as a poin ...

SPRINGERNATURE2020

Electron Spin Resonance Magnetometers for Particle Accelerators

Anthony Jean Beaumont

CERN is the European Organization for Nuclear Research located in Geneva, Switzerland. Its main goal is to explore fundamental physics and it exists primarily to provide physicists the necessary tools for doing this, namely accelerators. These tools bring ...

EPFL2020

Fully spin-polarized bulk states in ferroelectric GeTe

Jan Hugo Dil, Mauro Fanciulli

By measuring the spin polarization of GeTe films as a function of light polarization we observed that the bulk states are fully spin polarized in the initial state, in strong contrast with observations for other systems with a strong spin-orbit interaction ...

2020

Nonlinear evolution of the centrifugal instability using a semilinear model

François Gallaire, Eunok Yim

We study the nonlinear evolution of the axisymmetric centrifugal instability developing on a columnar anticyclone with a Gaussian angular velocity using a semilinear approach. The model consists of two coupled equations: one for the linear evolution of the ...

Cambridge University Press2020