scholarly journals Magnetic properties of the nucleon in a uniform background field

2014 ◽  
Vol 89 (3) ◽  
Author(s):  
Thomas Primer ◽  
Waseem Kamleh ◽  
Derek Leinweber ◽  
Matthias Burkardt
Keyword(s):  
Magnetic Properties ◽  
Background Field ◽  
Uniform Background

scholarly journals Magnetic properties of the neutron in a uniform background field

2012 ◽  
Author(s):  
Thomas Primer ◽  
Waseem Kamleh ◽  
Derek Leinweber ◽  
Matthias Burkardt
Keyword(s):  
Magnetic Properties ◽  
Background Field ◽  
Uniform Background

Particle acceleration by interstellar plasma shock waves in non-uniform background magnetic field

2020 ◽  
Vol 498 (4) ◽  
pp. 5517-5523
Author(s):  
P Rashed-Mohassel ◽  
M Ghorbanalilu
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Shock Waves ◽  
Electric Field ◽  
Background Field ◽  
Magnetized Plasma ◽  
Background Magnetic Field ◽  
Positive Variation ◽  
Uniform Background ◽  
Plasma Shock

ABSTRACT Particle acceleration by plasma shock waves is investigated for a magnetized plasma cloud propagating in a non-uniform background magnetic field by means of analytical and numerical calculations. The mechanism studied here is mainly, magnetic trapping acceleration (MTA) which is previously investigated for a cloud moving through the uniform interstellar magnetic field (IMF). In this work, the acceleration is studied for a cloud moving in an antiparallel background field with spatial variations along the direction of motion. For negative variation, the cloud moves towards an antiparallel magnetic field with an increasing intensity, the trapped particle moves to locations with higher convective electric field and therefore gains more energy over time. For positive variation, the background field decreases to zero and changes into a parallel field with an increasing intensity. It is concluded that, when the background field vanishes, the MTA mechanism ceases and the particle escapes into the space. This leads to a bouncing acceleration which further increases energy of the gyrating particle. The two processes are followed by a shock drift acceleration, where due to the background magnetic field gradient, the particle drifts along the electric field and gains energy. Although for positive variation, three different mechanisms are involved, energy gain is less than in the case of a uniform background field.

Magnetic Field

2013 ◽  
Author(s):  
Gary A. Glatzmaier
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Background Field ◽  
Magnetohydrodynamic Equations ◽  
Electrically Conducting ◽  
Background Magnetic Field ◽  
Nonlinear Simulations ◽  
Uniform Background ◽  
The Stability ◽  
2D Model

This chapter focuses on magnetoconvection, which refers to thermal convection of an electrically conducting fluid within a background magnetic field maintained by some external mechanism. It first provides a brief overview of magnetohydrodynamics and the magnetohydrodynamic equations before explaining how to make a 2D model of magnetic field. In this approach, the case of a uniform vertical background field and the case of a uniform horizontal background field are both considered. The chapter then describes how one could simulate a case of a uniform background field that is tilted relative to both the vertical and horizontal axes. It also considers what can be learned about the stability and structure of magnetoconvection and the dispersion relation for magneto-gravity waves from analytical analyses without the nonlinear terms. Finally, it discusses nonlinear simulations of magnetoconvection in a box with impermeable side boundaries, along with magnetoconvection with a horizontal background field and an arbitrary background field.

Stability of Alfvén wings in uniform plasmas

2007 ◽  
Vol 73 (6) ◽  
pp. 957-966
Author(s):  
P. A. SALLAGO ◽  
A. M. PLATZECK
Keyword(s):  
Solar System ◽  
Normal Modes ◽  
Background Field ◽  
Alfven Waves ◽  
Magnetized Plasma ◽  
Alfvén Waves ◽  
Solar System Bodies ◽  
Uniform Background ◽  
The Stability ◽  
Magnetohydrodynamic System

AbstractA conducting source moving uniformly through a magnetized plasma generates, among a variety of perturbations, Alfvén waves. An interesting characteristic of Alfvén waves is that they can build up structures in the plasma called Alfvén wings. These wings have been detected and measured in many solar system bodies, and their existence has also been theoretically proven. However, their stability remains to be studied. The aim of this paper is to analyze the stability of an Alfvén wing developed in a uniform background field, in the presence of an incompressible perturbation that has the same symmetry as the Alfvén wing, in the magnetohydrodynamic approximation. The study of the stability of a magnetohydrodynamic system is often performed by linearizing the equations and using either the normal modes method or the energy method. In spite of being applicable for many problems, both methods become algebraically complicated if the structure under analysis is a highly non-uniform one. Palumbo has developed an analytical method for the study of the stability of static structures with a symmetry in magnetized plasmas, in the presence of incompressible perturbations with the same symmetry as the structure (Palumbo 1998 Thesis, Universidad de Firenze, Italia). In the present paper we extend this method for Alfvén wings that are stationary structures, and conclude that in the presence of this kind of perturbation they are stable.

scholarly journals Nucleon Magnetic Properties from Lattice QCD And The Background Field Method

2017 ◽  
Author(s):  
Ryan Bignell ◽  
Derek Leinweber ◽  
Waseem Kamleh ◽  
Matthias Burkardt
Keyword(s):  
Magnetic Properties ◽  
Lattice Qcd ◽  
Background Field ◽  
Field Method ◽  
Background Field Method

Optoelectronic tweezers with a non-uniform background field

2020 ◽  
Vol 117 (17) ◽  
pp. 171102
Author(s):  
Mohammad Asif Zaman ◽  
Punnag Padhy ◽  
Yao-Te Cheng ◽  
Ludwig Galambos ◽  
Lambertus Hesselink
Keyword(s):  
Background Field ◽  
Optoelectronic Tweezers ◽  
Uniform Background

scholarly journals Background field Landau mode operators for the nucleon

2018 ◽  
Vol 175 ◽  
pp. 05018 ◽  
Author(s):  
Waseem Kamleh ◽  
Ryan Bignell ◽  
Derek B. Leinweber ◽  
Matthias Burkardt
Keyword(s):  
Magnetic Field ◽  
Correlation Function ◽  
Charged Particle ◽  
Finite Lattice ◽  
Background Field ◽  
Spatial Symmetry ◽  
Preliminary Results ◽  
Mode Effects ◽  
Background Magnetic Field ◽  
Uniform Background

The introduction of a uniform background magnetic field breaks threedimensional spatial symmetry for a charged particle and introduces Landau mode effects. Standard quark operators are inefficient at isolating the nucleon correlation function at nontrivial field strengths. We introduce novel quark operators constructed from the twodimensional Laplacian eigenmodes that describe a charged particle on a finite lattice. These eigenmode-projected quark operators provide enhanced precision for calculating nucleon energy shifts in a magnetic field. Preliminary results are obtained for the neutron and proton magnetic polarisabilities using these methods.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

1988 ◽  
Vol 46 ◽  
pp. 770-771
Author(s):  
June D. Kim
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Ternary Phase Diagram ◽  
Vertical Tube ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Soft Magnetic ◽  
Quenching Temperature ◽  
Thin Foils ◽  
Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

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