scholarly journals Laboratory astrophysics with laser-driven strong magnetic fields in China

2016 ◽  
Vol 4 ◽  
Author(s):  
Fei-Lu Wang ◽  
Xiao-Xing Pei ◽  
Bo Han ◽  
Hui-Gang Wei ◽  
Da-Wei Yuan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
National Laboratory ◽  
Laboratory Astrophysics ◽  
High Power Lasers ◽  
Strong Magnetic Fields ◽  
Atomic Structures ◽  
Shock Wave Generation ◽  
Laser Facility

In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.

STABILITY OF DEUTERONS IN STRONG MAGNETIC FIELDS: AN EXACTLY SOLVED MODEL

1988 ◽  
Vol 03 (04) ◽  
pp. 345-351 ◽  
Author(s):  
M. MOSHINSKY ◽  
G. LOYOLA
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Triplet State ◽  
Strong Magnetic Field ◽  
Canonical Transformation ◽  
Singlet State ◽  
Oscillator Potential ◽  
Strong Magnetic Fields ◽  
Expectation Value ◽  
The Magnetic Field

We consider the nucleons in the triplet state of the deuteron bound by an oscillator potential and in a strong magnetic field. Using an appropriate linear canonical transformation, we solve the problem exactly. The expectation value of the distance between the nucleons in the plane perpendicular to the magnetic field diminishes slowly as we increase the latter, which suggests that the triplet state of the deuteron is stable. The conclusion is not altered when we consider possible transitions from the triplet to the singlet state due to the action of the magnetic field on the spins.

scholarly journals A method of producing strong magnetic fields

1924 ◽  
Vol 105 (734) ◽  
pp. 691-710 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Strong Magnetic Field ◽  
Present Theory ◽  
Iron Core ◽  
Strong Magnetic Fields ◽  
Ferro Magnetic ◽  
Magnetic Resistance

There are only two methods of producing a strong magnetic field. The first is by a solenoid, and the second by a solenoid with an iron core in it. The iron is introduced for the purpose of diminishing the magnetic resistance of the magnetic flux, and makes possible the production of much stronger fields than can be obtained without it. This is the principle on which modern electro-magnets are constructed, and by means of them it is possible to obtain field up to 60 kilogauss in a volume of a few cubic millimetres. The saturation of iron, however, makes it impossible to go further than this. According to the present theory of ferro-magnetism we can hardly hope to obtain any ferro-magnetic material which will give a much higher saturation-value than the iron used in modern electro-magnets; and without such a material it is impossible to increase the field obtainable by this means.

scholarly journals Quantum Dots in Strong Magnetic Fields: Stability Criteria for the Maximum Density Droplet

1993 ◽  
Vol 46 (3) ◽  
pp. 345 ◽  
Author(s):  
AH MacDonald ◽  
SR Eric Yang ◽  
MD Johnson
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
Ground State ◽  
Slater Determinant ◽  
Pauli Exclusion Principle ◽  
Maximum Density ◽  
Exclusion Principle ◽  
Strong Magnetic Fields ◽  
Electron Interactions

In this article we discuss the ground state of a parabolically confined quantum dot in the limit of very strong magnetic fields where the electron system is completely spin-polarised and all electrons are in the lowest Landau level. Without electron-electron interactions the ground state is a single Slater determinant corresponding to a droplet centred on the minimum of the confinement potential and occupying the minimum area allowed by the Pauli exclusion principle. Electron-electron interactions favour droplets of larger area. We derive exact criteria for the stability of the maximum density droplet against edge excitations and against the introduction of holes in the interior of the droplet. The possibility of obtaining exact results in the strong magnetic field case is related to important simplifications associated with broken time-reversal symmetry in a strong magnetic field.

scholarly journals EFFECT OF STRONG MAGNETIC FIELDS ON THE EQUILIBRIUM OF A DEGENERATE GAS OF NUCLEONS AND ELECTRONS

1996 ◽  
Vol 10 (23) ◽  
pp. 1141-1149 ◽  
Author(s):  
CHOON-LIN HO ◽  
V.R. KHALILOV ◽  
CHI YANG
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Strong Magnetic Field ◽  
Constant Magnetic Field ◽  
Fermi Momentum ◽  
Magnetic Field Induction ◽  
Strong Magnetic Fields ◽  
Field Induction ◽  
The Magnetic Field

We obtain the equations that define the equilibrium of a homogeneous relativistic gas of neutrons, protons and electrons in a constant magnetic field as applied to the conditions that probably occur near the center of neutron stars. We compute the relative densities of the particles at equilibrium and the Fermi momentum of electrons in the strong magnetic field as function of the density of neutrons and the magnetic field induction. Novel features are revealed as to the ratio of the number of protons to the number of neutrons at equilibrium in the presence of large magnetic fields.

scholarly journals α-ray tracks in a strong magnetic field

1924 ◽  
Vol 106 (739) ◽  
pp. 602-622 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
Experimental Results ◽  
Single Atom ◽  
Expansion Chamber ◽  
Strong Magnetic Fields ◽  
Wilson Expansion ◽  
Short Period ◽  
Preliminary Account

When an α -particle moves in a magnetic field it describes a curved trajectory, the curvature of which is closely related to its charge and velocity. Thus the track of an α -particle obtained in a Wilson expansion chamber, placed in a magnetic field, will be no longer straight, but curved. From study of these curved tracks it should be possible to obtain information about the loss of energy and the change of the charge of a single atom moving through matter. The difficulty of this experiment is the necessity of using a strong magnetic field. The author has recently published a description of a method of producing strong magnetic fields for a small fraction of a second. The strength of these fields is of the order required for this kind of experiment, and the short period of time (0•01 sec.) during which the field is available is still very long compared with the time taken by the α -particle to describe its trajectory (1.0•10 -7 sec.). A preliminary account of this experiment has already been published, but it took about a year to complete the experimental results. In the present paper the description is given of the experimental arrangements used and of the results obtained.

scholarly journals INFLUENCE OF THE SADDLE-SPLAY CONSTANT ON THE DIRECTOR FIELD DISTRIBUTION IN STRONG MAGNETIC FIELDS

2017 ◽  
Vol 20 (3) ◽  
pp. 128-135
Author(s):  
A.A. Kudreyko ◽  
R.N. Migranova ◽  
A.R. Khafizov
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
Parallel Plates ◽  
Lagrange Equations ◽  
Director Field ◽  
Strong Magnetic Fields ◽  
Anchoring Effects

The role of anchoring effects in thin nematic films confined between two parallel plates was theoretically examined. The bulk and surface free energy densities weree xpanded up to O(e2) and the perturbated contributions were calculated. It is shown that the minimum of the free energy corresponds to the solution of the Euler-Lagrange equations and satisfies the Ericksen inequalities. The identified bifurcation points can estimate the influence of the saddle-splay constant k24 towards periodic perturbations of a director in the presence of strong magnetic field.

scholarly journals Hydrogen Atom and One-Electron Molecular Systems in a Strong Magnetic Field: Are All of Them Alike

2005 ◽  
Vol 70 (8) ◽  
pp. 1133-1156 ◽  
Author(s):  
Alexander V. Turbiner ◽  
Alexei B. Kaidalov ◽  
Juan Carlos López Vieyra
Keyword(s):  
Magnetic Field ◽  
Hydrogen Atom ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
Quadrupole Moment ◽  
Molecular Ions ◽  
Binding Energies ◽  
Strong Magnetic Fields ◽  
Molecular Systems ◽  
The One

Easy physics-inspired approximations of the total and binding energies for the H atom and for the molecular ions H2(+)(ppe), H3(2+)(pppe), (HeH)++(αpe), He2(3+)(ααe) as well as quadrupole moment for the H atom and the equilibrium distances of the molecular ions in strong magnetic fields > 109 G are proposed. The idea of approximation is based on the assumption that the dynamics of the one-electron Coulomb system in a strong magnetic field is governed by the ratio of transverse to longitudinal sizes of the electronic cloud.

scholarly journals The measurement of the energy of cosmic rays - II—The curvature measurements and the energy spectrum

1936 ◽  
Vol 154 (883) ◽  
pp. 573-587 ◽  
Keyword(s):  
Magnetic Field ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Strong Magnetic Fields ◽  
The Earth ◽  
Primary Particles ◽  
Curvature Measurements

Both the penetrating power of the cosmic rays through material ab­sorbers and their ability to reach the earth in spite of its magnetic field, make it certain that the energy of many of the primary particles must reach at least 10 11 e-volts. However, the energy measurements by Kunze, and by Anderson, using cloud chambers in strong magnetic fields, have extended only to about 5 x 10 9 e-volts. Particles of greater energy were reported, but the curvature of their tracks was too small to be measured with certainty. We have extended these energy measurements to somewhat higher energies, using a large electro-magnet specially built for the purpose and described in Part I. As used in these experiments, the magnet allowed the photography of tracks 17 cm long in a field of about 14,000 gauss. The magnet weighed about 11,000 kilos and used a power of 25 kilowatts.

scholarly journals Implementation of a Faraday rotation diagnostic at the OMEGA laser facility

2018 ◽  
Vol 6 ◽  
Author(s):  
A. Rigby ◽  
J. Katz ◽  
A. F. A. Bott ◽  
T. G. White ◽  
P. Tzeferacos ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Faraday Rotation ◽  
Field Measurements ◽  
Thomson Scattering ◽  
Proton Radiography ◽  
Time Resolved ◽  
Rotation Measurement ◽  
Laser Facility ◽  
Omega Laser

Magnetic field measurements in turbulent plasmas are often difficult to perform. Here we show that for ${\geqslant}$kG magnetic fields, a time-resolved Faraday rotation measurement can be made at the OMEGA laser facility. This diagnostic has been implemented using the Thomson scattering probe beam and the resultant path-integrated magnetic field has been compared with that of proton radiography. Accurate measurement of magnetic fields is essential for satisfying the scientific goals of many current laser–plasma experiments.

scholarly journals Magnetic dominance of axion electrodynamics: photon capture effect and anisotropy of Coulomb potential

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
S. Villalba-Chávez ◽  
A. E. Shabad ◽  
C. Müller
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Strong Magnetic Field ◽  
Coulomb Potential ◽  
Heat Radiation ◽  
Radiation Mechanism ◽  
Electron Positron ◽  
Coulomb Singularity ◽  
Relativistic Hydrogen ◽  
The Magnetic Field

AbstractFor magnetic fields larger than the characteristic scale linked to axion-electrodynamics, quantum vacuum fluctuations due to axion-like fields can dominate over those associated with the electron-positron fields. This conjecture is explored by investigating both the axion-modified photon capture by a strong magnetic field and the Coulomb potential of a static pointlike charge. We show that in magnetic fields characteristic of neutron stars $$\sim 10^{13}$$ ∼ 10 13 –$$10^{15}\;\mathrm{G}$$ 10 15 G , the capture of gamma photons prior to the production of a pair can prevent the existence of an electron-positron plasma, essential for explaining the pulsar radiation mechanism. This incompatibility is used to limit the axion parameter space. Our bounds improve existing outcomes in the region of mass $$m\sim 10^{-10}$$ m ∼ 10 - 10 –$$10^{-5}\;{\mathrm{eV}}$$ 10 - 5 eV . The effect of capture, known in QED as relating to gamma-quanta, is extended in axion electrodynamics to include X-ray photons with the result that a specially polarized part of the heat radiation from the surface is canalized along the magnetic field. Besides, we find that in the regime in which the dominance takes place, the running QED coupling depends on the field strength and the modified Coulomb potential is of Yukawa-type in the direction perpendicular to the magnetic field at distances much smaller than the axion Compton wavelength, while along the field it follows approximately the Coulomb law at any length scale. Despite the Coulomb singularity manifested in the latter case, we argue that the ground-state energy of a non-relativistic hydrogen atom placed in a strong magnetic field turns out to be bounded due to the nonrenormalizable feature of axion-electrodynamics.

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