Extreme Electromagnetic Fields Research Articles

The science case for an intermediate energy advanced and novel accelerator linear collider facility

It is widely accepted that the next lepton collider beyond a Higgs factory would require center-of-mass energy of the order of up to 15 TeV. Since, given reasonable space and cost restrictions, conventional accelerator technology reaches its limits near this energy, high-gradient advanced acceleration concepts are attractive. Advanced and novel accelerators (ANAs) are leading candidates due to their ability to produce acceleration gradients on the order of 1–100 GV/m, leading to compact acceleration facilities. However, intermediate energy facilities (IEF) are required to test the critical technology elements on the way towards multi-TeV-class collliders. Here a science case for a 20–100 GeV center-of-mass energy ANA-based lepton collider that can be a candidate for an intermediate energy facility is presented. The IEF can provide numerous opportunities for high energy physics studies including precision Quantum Chromodynamics and Beyond the Standard Model physics measurements, investigation of charged particle interactions with extreme electromagnetic fields, and exploring muon and proton beam acceleration. Possible applications of this collider include the studies of γγ and electron beam-fixed target/beamdump collider designs. Thus, the goal of the proposed IEF is to both carry out particle physics measurements in the 20-100 GeV ranges as well as to serve as an ANA demonstrator facility.

SFQEDtoolkit: A high-performance library for the accurate modeling of strong-field QED processes in PIC and Monte Carlo codes

Strong-field quantum electrodynamics (SFQED) processes are central in determining the dynamics of particles and plasmas in extreme electromagnetic fields such as those present in the vicinity of compact astrophysical objects or generated with ultraintense lasers. SFQEDtoolkit is an open source library designed to allow users for a straightforward implementation of SFQED processes in existing particle-in-cell (PIC) and Monte Carlo codes. Through advanced function approximation techniques, high-energy photon emission and electron-positron pair creation probability rates and energy distributions are calculated within the locally-constant-field approximation (LCFA) as well as with more advanced models [Phys. Rev. A 99, 022125 (2019)]. SFQEDtoolkit is designed to provide users with high-performance and high-accuracy, and neat examples showing its usage are provided. In the near future, SFQEDtoolkit will be enriched to model the angular distribution of the generated particles, i.e., beyond the commonly employed collinear emission approximation, as well as to model spin and polarization dependent SFQED processes. Notably, the generality and flexibility of the presented function approximation approach makes it suitable to be employed in other areas of physics, chemistry and computer science. Program summaryProgram Title: SFQEDtoolkit (version 1.0)CPC Library link to program files:https://doi.org/10.17632/j7mhj3cg3m.1Developer's repository link:https://github.com/QuantumPlasma/SFQEDtoolkitLicensing provisions: GPLv3Programming language: C++, FortranNature of problem: The accurate simulation of strong-field QED processes in the interaction of particles or plasmas with strong electromagnetic fields is critical for present and future experiments with ultraintense lasers as well as to unveil the dynamics around compact astrophysical objects. State-of-the-art PIC and Monte Carlo codes implement strong-field QED processes by means of lookup tables, where the approximated function is evaluated on a fixed set of points. This typically results in numerical artifacts such as stairlike structures in the approximated function, and in a reduced efficiency when large size lookup tables are necessary. An easily implementable open-source accurate and efficient simulation tool is required to address problems at the high-intensity frontier of plasma physics and astrophysics.Solution method: Strong-field QED process rates and particle distributions are calculated by leveraging advanced approximation methods based on variable and function transformation, asymptotic expansions as well as Chebyshev polynomial expansions. This provides a numerically-stable and efficient approach that allows us to overcome all limitations of existing methods based on standard lookup tables.

A combination of failures of interfacial delamination and layer cracking in REBCO multilayered conductors

Rare-earth barium-copper-oxide (REBCO) coated conductors (CCs) are kinds of multiphase, multilayer, and composited superconducting tapes, which are becoming promising candidates for abundant high-energy and high-field applications owing to their outstanding superconducting properties. However, the mechanical failures of REBCO CCs composites, such as cracks in the brittle ceramic layers, and delamination on interfaces among weak multiple layers, have become the essential issues threatening the capability and stable operation of REBCO-based superconducting devices, especially under extreme low temperature and complex electromagnetic fields. In this study, a failure modeling in combination of the interfacial delamination and layer fracture in REBCO CCs composites was established and analyzed numerically by the finite element method. To effectively treat with the two mechanical failure modes, the interfacial delamination response and the fracture behavior were respectively captured using the cohesive zone model and the extended finite element method for the multilayered superconducting CCs. The failures initiation and evolution in REBCO multilayered structures were implemented based on the stress criteria. The characteristics of two failure modes of the multilayered superconducting CCs under uniaxial tension and bending were investigated, and those during cooling process from room temperature to 77 K were then simulated in consideration of residual thermal stresses accumulated. The results illustrated that the progressive mechanical failure behaviors were presented in combination of the interfacial delamination and fracture damages in the REBCO multilayered structure. The crack propagation in the superconducting layer can cause the delamination failure at the corresponding position on the interfaces between the superconducting layer and its adjacent layers, while the delamination damage on the interfaces releases the constraint between the layers further enhances the crack propagation. The residual thermal stress accumulated during cooling was found to significantly affect the mechanical behavior of the REBCO CCs, and the low-temperature makes a failure occurrence earlier compared to that at room temperature.

Features of the Generation of Extreme Electromagnetic Fields in a Mesoscale Dielectric Sphere with Regard to the Environment

Features of the Generation of Extreme Electromagnetic Fields in a Mesoscale Dielectric Sphere with Regard to the Environment

Peculiarities of Generation of Extreme Electromagnetic Fields in a Dielectric Mesoscale Sphere with the presence of the Environment

The results of numerical simulation based on the Mie theory of the effect of superresonance (high-order Fano resonance) for a mesoscale dielectric sphere immersed in air are presented, since the environment in the form of a vacuum is an idealization that is almost never realized in nature. Using the example of a particle with a refractive index of 1.5 and a size parameter q~ 26 and q~ 38, it was demonstrated for the first time that a change in the refractive index of the environment by 2.4· 10-4 leads to a decrease in the field intensity in the region of the shadow pole of the sphere by an order of magnitude and a shift of the resonant value of the size parameter q to the short-wavelength region. In this case, the relative intensities of the resonant peaks for both the magnetic and electric fields in the vicinity of the poles of the sphere in the optical range can reach values characteristic of a particle in vacuum (of the order of 106-107), with an appropriate adjustment of the resonant size parameter. Keywords: high-order Fano resonance, superresonance, mesotronics, field intensity, extreme magnetic field.

Kinetic Model of Large-amplitude Oscillations in Neutron Star Pair Cascades

Abstract Electron–positron pair cascades developed in the extreme electromagnetic fields of neutron star polar caps are considered a key source of magnetospheric plasma in these objects. We use a simplified model that maps the quantum electrodynamics processes governing pair cascades to analytically and numerically model these cascades, and show that large-amplitude oscillations of the electric field are inductively driven by the resulting plasma. A plasma instability arises in these oscillations, and particles accelerated in growing electric field perturbations can drive secondary pair bursts that damp the large-amplitude oscillations. An analytical model is proposed to describe this interplay between the pair production and kinetic collective plasma processes. All analytical results are shown to be in excellent agreement with particle-in-cell simulations.

Disentangling x-ray dichroism and birefringence via high-purity polarimetry

High-brilliance synchrotron radiation sources have opened new avenues for x-ray polarization analysis that go far beyond conventional polarimetry in the optical domain. With linear x-ray polarizers in a crossed setting, polarization extinction ratios down to 10 − 10 can be achieved. This renders the method sensitive to probe the tiniest optical anisotropies that would occur, for example, in strong-field quantum electrodynamics due to vacuum birefringence and dichroism. Here we show that high-purity polarimetry can be employed to reveal electronic anisotropies in condensed matter systems with utmost sensitivity and spectral resolution. Taking CuO and L a 2 C u O 4 as benchmark systems, we present a full characterization of the polarization changes across the Cu K-absorption edge and their separation into dichroic and birefringent contributions. At diffraction-limited synchrotron radiation sources and x-ray lasers, where polarization extinction ratios of 10 − 12 can be achieved, our method has the potential to assess birefringence and dichroism of the quantum vacuum in extreme electromagnetic fields.

Search for extreme electromagnetic fields through measurements of charm mesons flow harmonics in PbPb collisions at 5.02 TeV with the CMS detector

In ultrarelativistic heavy-ion collisions, a very strong (on the order of 1016 T) and transient (lifetime on the order of 10−1 fm/c) electromagnetic (EM) field is expected to be generated inside the medium formed in the collision. This EM field, generated by the collision participants and spectators, is predicted to produce a difference in the νn harmonics for positive-and negative-charged particles, with the magnetic field mainly responsible for a splitting in rapidity-odd directed flow (ν1), and the Coulomb electric field leading to a charge-dependent splitting in the ν2 and average pT values of emitted particles. Due to the large mass, charm quarks are expected to be created very early in the collision, and thus have more chance of interacting with this strong EM field than light flavor hadrons. In this contribution, measurements of D0 (u‾c) and D‾0uc‾) mesons flow harmonics (ν2 and ν3) are presented as functions of rapidity (y), transverse momentum, and collision centrality for PbPb collisions at 5.02 TeV, using the large data samples collected by the CMS experiment during the LHC Run 2. The wide rapidity coverage (|y| < 2) of these new charm mesons measurements allow for a better understanding of the 3-dimensional evolution of the medium formed in heavy-ion collisions.

Initial transverse-momentum broadening of Breit-Wheeler process in relativistic heavy-ion collisions

We calculate the cross section and transverse-momentum (P⊥) distribution of the Breit-Wheeler process in relativistic heavy-ion collisions and their dependence on collision impact parameter (b). To accomplish this, the Equivalent Photon Approximation (EPA) was generalized in a more differential way compared to the approach traditionally used for inclusive collisions. In addition, a lowest-order QED calculation with straightline assumption was performed as a standard baseline for comparison. The cross section as a function of b is consistent with previous calculations using the equivalent one-photon distribution function. Most importantly, the P⊥ shape from this model is strongly dependent on impact parameter and can quantitatively explain the P⊥ broadening observed recently by RHIC and LHC experiments. This broadening effect from the initial QED field strength should be considered in studying possible trapped magnetic field and multiple scattering in a Quark-Gluon Plasma (QGP). The impact-parameter sensitive observable also provides a controllable tool for studying extreme electromagnetic fields.

Compact Multistage Plasma-Based Accelerator Design for Correlated Energy Spread Compensation.

The extreme electromagnetic fields sustained by plasma-based accelerators could drastically reduce the size and cost of future accelerator facilities. However, they are also an inherent source of correlated energy spread in the produced beams, which severely limits the usability of these devices. We propose here to split the acceleration process into two plasma stages joined by a magnetic chicane in which the energy correlation induced in the first stage is inverted such that it can be naturally compensated in the second. Simulations of a particular 1.5-m-long setup show that 5.5GeV beams with relative energy spreads of 1.2×10^{-3} (total) and 2.8×10^{-4} (slice) could be achieved while preserving a submicron emittance. This is at least one order of magnitude below the current state of the art and would enable applications such as compact free-electron lasers.

Prospect of Studying Nonperturbative QED with Beam-Beam Collisions.

We demonstrate the experimental feasibility of probing the fully nonperturbative regime of quantum electrodynamics with a 100GeV-class particle collider. By using tightly compressed and focused electron beams, beamstrahlung radiation losses can be mitigated, allowing the particles to experience extreme electromagnetic fields. Three-dimensional particle-in-cell simulations confirm the viability of this approach. The experimental forefront envisaged has the potential to establish a novel research field and to stimulate the development of a new theoretical methodology for this yet unexplored regime of strong-field quantum electrodynamics.

New light in nuclear physics: The extreme light infrastructure

Extreme Light Infrastructure-Nuclear Physics (ELI-NP), to become operational in 2019, is a new Research Center built in Romania that will use extreme electromagnetic fields for nuclear physics research. The ELI-NP facility will combine two large equipments with state-of-the-art parameters, namely a 2 × 10 PW high-power laser system and a very brilliant gamma-beam system delivering beams with energies up to 19.5 MeV. The laser and gamma-beam systems under construction and typical proposed first-phase experiments are described.

Extreme Light Infrastructure Nuclear Physics (ELI–NP): Present status and perspectives

Extreme Light Infrastructure – Nuclear Physics (ELI–NP), a new Research Center under construction, will use extreme electromagnetic fields for nuclear physics research and will be operational in 2018. The status of the Project implementation will be presented. At ELI–NP, a high power laser system together with a very brilliant gamma beam are the two main research tools. Their targeted operational parameters will be described. The related experimental set-ups will be presented, together with the main directions of the research envisioned.

The ELI–NP facility for nuclear physics

Extreme Light Infrastructure–Nuclear Physics (ELI–NP) is aiming to use extreme electromagnetic fields for nuclear physics research. The facility, currently under construction at Magurele–Bucharest, will comprise a high power laser system and a very brilliant gamma beam system. The technology involved in the construction of both systems is at the limits of the present-day’s technological capabilities. The high power laser system will consist of two 10PW lasers and it will produce intensities of up to 1023–1024W/cm2. The gamma beam, produced via Compton backscattering of a laser beam on a relativistic electron beam, will be characterized by a narrow bandwidth (<0.5%) and tunable energy of up to almost 20MeV. The research program of the facility covers a broad range of key topics in frontier fundamental physics and new nuclear physics. A particular attention is given to the development of innovative applications. In the present paper an overview of the project status and the overall performance characteristics of the main research equipment will be given. The main fundamental physics and applied research topics proposed to be studied at ELI–NP will also be briefly reviewed.

Extreme-field physics in Penning traps

We present two Penning trap experiments concerned with different aspects of the physics of extreme electromagnetic fields, the ARTEMIS experiment designed for bound-electron magnetic moment measurements in the presence of the extremely strong fields close to the nucleus of highly charged ions, and the HILITE experiment, in which well-defined ion targets are to be subjected to high-intensity laser fields.

Future Experiments with Intense Laser Beams and Brilliant Gamma Beams at the ELI-NP Facility

The Extreme Light Infrastructure (ELI) Pan-European facility initiative represents a major step forward in quest for extreme electromagnetic fields. Extreme Light Infrastructure Nuclear Physics (ELI-NP) is one of the three pillars of the ELI facility, that aims to use extreme electromagnetic fields for nuclear physics and quantum electrodynamics research. At ELI-NP, high-power lasers together with a very brilliant gamma beam are the main research tools. Their targeted operational parameters are described. The emerging experimental program in the field of nuclear physics of the facility is reported. The different instruments which are considered to operate in the ELI-NP experimental halls are discussed, with an emphasis on the instrumentation which is designed for nuclear structure, reactions and astrophysics research.

Photoneutron cross section measurements on Sm isotopes

The Extreme Light Infrastructure - Nuclear Physics, one of the three pillars of the Extreme Light Infrastructure Pan-European initiative, is a new large scale facility dedicated to nuclear physics with extreme electromagnetic fields. ELI-NP will host two 10 PW lasers and a very brilliant Gamma beam system with unprecedented intensity and energy resolution parameters. We propose to perform photon induced nuclear reactions using the very brilliant γ -ray beams provided by the Gamma beam system to examine in detail the photon absorption process and its decay modes. Here the experimental program related to nuclear research on reactions above the neutron separation threshold, which is under preparation at ELI-NP, is presented.

Towards experiments at the new ELI-NP facility

The Extreme Light Infrastructure (ELI) Pan-European initiative represents a major step forward in quest for extreme electromagnetic fields. The Extreme Light Infrastructure – Nuclear Physics (ELI-NP) laboratory is one of the three pillars of the ELI project, that aims to use such extreme electromagnetic fields for nuclear physics and quantum electrodynamics research. At ELI-NP two ten petawatt high-power laser systems together with a very brilliant narrow-width γ beam are the main research tools. Here the current status of the project and the experimental program related to nuclear research, which is under preparation at ELI-NP, are presented.

Extreme Light Infrastructure – Nuclear Physics (ELI-NP) European Research Centre

Extreme Light Infrastructure (ELI) is one of the 48 infrastructures of the European Strategic Forum for Research Infrastructure (ESFRI) roadmap and represents a major step forward in quest for producing extreme electromagnetic fields. Extreme Light Infrastructure – Nuclear Physics (ELI-NP) is one of the three pillars of the ELI initiative, which aims to use extreme electromagnetic fields for nuclear physics research. A high power laser system and a very brilliant gamma beam are the two main research equipment at the core of ELI-NP. Their targeted operational parameters are described. The related experimental areas are also presented, together with the main directions of the proposed scientific programme.

SPARC experiments at the high-energy storage ring

The physics program of the SPARC collaboration at the Facility for Antiproton and Ion Research (FAIR) focuses on the study of collision phenomena in strong and even extreme electromagnetic fields and on the fundamental interactions between electrons and heavy nuclei up to bare uranium. Here we give a short overview on the challenging physics opportunities of the high-energy storage ring at FAIR for future experiments with heavy-ion beams at relativistic energies with particular emphasis on the basic beam properties to be expected.