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The usage of numerical models to study the evolution of particle beams is an essential step in the design process of particle accelerators However, uncertainties of input quantities such as beam energy and magnetic field lead to simulation…

Accelerator Physics · Physics 2019-07-03 Matthias Frey , Jochem Snuverink , Christian Baumgarten , Andreas Adelmann

Particle acceleration in solar flares remains an outstanding problem in solar physics. It is yet unclear which of the acceleration mechanisms dominates and how exactly is the excessive magnetic energy transferred to the nonthermal and other…

Solar and Stellar Astrophysics · Physics 2019-09-25 Alexander T. Altyntsev , Nataliia S. Meshalkina , Alexandra L. Lysenko , Gregory D. Fleishman

Particle acceleration consequences from fluctuating electric fields superposed on an X-type magnetic field in collisionless solar plasma are studied. Such a system is chosen to mimic generic features of dynamic reconnection, or the…

Astrophysics · Physics 2009-11-13 P. Petkaki , A. L. MacKinnon

In this work, we investigate multiphoton and optical-field tunneling emission from metallic surfaces with nanoscale vacuum gaps. Using time-dependent Schrodinger equation (TDSE) simulations, we find that the properties of the emitted…

We consider a dark sector model containing stable fermions charged under an unbroken $U(1)$ gauge interaction, with a massless dark photon as force carrier, and interacting with ordinary matter via scalar messengers. We study its early…

High Energy Physics - Phenomenology · Physics 2020-10-14 Jan Tristram Acuña , Marco Fabbrichesi , Piero Ullio

Coupling dark energy to dark matter provides one of the simplest way to effectively modify gravity at large scales without strong constraints from local (i.e. solar system) observations. Models of coupled dark energy have been studied…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Luca Amendola , Valeria Pettorino , Claudia Quercellini , Adrian Vollmer

The motion-induced drag force acting on a particle moving parallel to an arrangement of $N$ objects is analyzed. Particular focus is placed on the nonequilibrium statistics of the interaction and on the interplay between the system's…

Quantum Physics · Physics 2020-05-14 Daniel Reiche , Kurt Busch , Francesco Intravaia

We explore a regime of laser-driven plasma acceleration of electrons where the radial envelope of the laser-pulse incident at the plasma entrance is strongly mismatched to the nonlinear plasma electron response excited by it. This regime…

Plasma Physics · Physics 2017-04-11 A. A. Sahai , K. Poder , J. C. Wood , J. M. Cole , N. C. Lopes , S. P. D. Mangles , Z. Najmudin

Magnetic confinement fusion researches are an approach to demonstrate the feasibility of nuclear fusion power for energy production. In these experiments, mega-watt range power Radio-Frequency waves, from tens of MHz to hundreds of GHz, are…

Plasma Physics · Physics 2017-10-11 Julien Hillairet , Marc Goniche , Nicolas Fil , Mohamed Belhaj , Jérôme Puech

The potential barrier model considering an additional current that can lead to the high-gradient breakdowns in accelerating structures is proposed. An oscillatory resonance feature of the field emission current from a double-layer metal…

Mesoscale and Nanoscale Physics · Physics 2023-06-29 I. I. Musiienko , S. O. Lebedynskyi , R. I. Kholodov

(abridged) We present results of test-particle simulations on both the first and the second order Fermi acceleration at relativistic parallel shock waves. We consider two scenarios for particle injection: (i) particles injected at the shock…

Astrophysics · Physics 2009-11-10 Joni J. P. Virtanen , Rami Vainio

As constraints on ultralight axion-like particles (ALPs) tighten, models with multiple species of ultralight ALP are of increasing interest. We perform simulations of two-ALP models with particles in the currently supported range…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-14 Noah Glennon , Nathan Musoke , Chanda Prescod-Weinstein

After Amdahl's trailblazing work, many other authors proposed analytical speedup models but none have considered the limiting effect of the memory wall. These models exploited aspects such as problem-size variation, memory size,…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-05-11 Alex F. A. Furtunato , Kyriakos Georgiou , Kerstin Eder , Samuel Xavier-de-Souza

New particle acceleration schemes open up exciting opportunities, potentially providing more compact or higher-energy accelerators. The AWAKE experiment at CERN is currently taking data to establish the method of proton-driven plasma…

Accelerator Physics · Physics 2019-09-04 M. Wing

Solar flares involve complex processes that are coupled and span a wide range of temporal, spatial, and energy scales. Modeling such processes self-consistently has been a challenge in the past. Here we present results from simulations that…

Solar and Stellar Astrophysics · Physics 2015-11-18 Fatima Rubio da Costa , Wei Liu , Vahe' Petrosian , Mats Carlsson

When a beam propagates in an accelerator, it interacts with both the external fields and the self-generated electromagnetic fields. If the latter are strong enough, the interplay between them and a perturbation in the beam distribution…

Accelerator Physics · Physics 2016-01-21 G. Rumolo

Power density constraints are limiting the performance improvements of modern CPUs. To address this, we have seen the introduction of lower-power, multi-core processors, but the future will be even more exciting. In order to stay within the…

Radio Frequency Quadrupole (RFQ) accelerators often need to face the challenges of space charge effects from high beam currents. This study investigated how to reach RFQ beam dynamics designs with not only high beam transmission and short…

Accelerator Physics · Physics 2019-10-23 Chuan Zhang , Holger Podlech

The electromagnetic wakefields excited by the bunches of charged particles in the particle accelerators may cause instability in the longitudinal and transverse motion of these bunches leading to the beam loss. These multibunch effects need…

Accelerator Physics · Physics 2021-04-19 Muhammad Shumail

Field emitted electrons can seriously affect the operation of high-field, high-duty factor electron accelerators. Accelerated field emission can result in high average power beams which can radiation damage beamline components. In addition,…

Accelerator Physics · Physics 2022-12-16 David H. Dowell , Munther Hindi , S. B. van der Geer , M. J. de Loos