scholarly journals Magnetic field of rectangular current loop with sides parallel and perpendicular to the surface of high-permeability material

2014 ◽  
Vol 11 (4) ◽  
pp. 701-717
Author(s):  
Anamarija Juhas ◽  
Neda Pekaric-Nadj ◽  
Hannes Toepfer
Keyword(s):  
Magnetic Field ◽  
Closed Form ◽  
Current Loop ◽  
High Permeability ◽  
Method Of Images ◽  
Infinite Blocks ◽  
Paper Method

In this paper, method of current images is used to calculate magnetic field of a rectangular loop in presence of high-permeability material. We provide closed form description for the images of the current loop placed between two semi-infinite blocks of high-permeability material, in the cases when the plane of the loop is parallel or perpendicular to the surfaces of blocks. A case study of using the method of images to calculate magnetic field of rectangular loop inside cube made of high-permeability material is also provided.

scholarly journals MAGNETIC FIELD OF COAXIAL SQUARE COILS ENCLOSED WITH HIGH-PERMEABILITY MATERIAL

2018 ◽  
Vol 8 (2) ◽  
pp. 30-34
Author(s):  
Anamarija Juhas ◽  
Neda Pekaric Nad ◽  
Hannes Toepfer
Keyword(s):  
Magnetic Field ◽  
Closed Form ◽  
High Permeability ◽  
Method Of Images ◽  
Helmholtz Coils

In this paper, the method of images is used to model the effects of enclosure made of high-permeability material on magnetic field of square coils. Closed-form description for the images, along with the case study involving square Helmholtz coils, is provided.

scholarly journals Balanced, bi-planar magnetic field and field gradient coils for field compensation in wearable magnetoencephalography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Niall Holmes ◽  
Tim M. Tierney ◽  
James Leggett ◽  
Elena Boto ◽  
Stephanie Mellor ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Permeability ◽  
Method Of Images ◽  
Gradient Coils ◽  
Coil System ◽  
Field Gradients ◽  
Spatially Inhomogeneous ◽  
Shielding Factor ◽  
Planar Coil ◽  
Field Uniformity

Abstract To allow wearable magnetoencephalography (MEG) recordings to be made on unconstrained subjects the spatially inhomogeneous remnant magnetic field inside the magnetically shielded room (MSR) must be nulled. Previously, a large bi-planar coil system which produces uniform fields and field gradients was used for this purpose. Its construction presented a significant challenge, six distinct coils were wound on two 1.6 × 1.6 m2 planes. Here, we exploit shared coil symmetries to produce coils simultaneously optimised to generate homogenous fields and gradients. We show nulling performance comparable to that of a six-coil system is achieved with this three-coil system, decreasing the strongest field component Bx by a factor of 53, and the strongest gradient dBx/dz by a factor of 7. To allow the coils to be used in environments with temporally-varying magnetic interference a dynamic nulling system was developed with a shielding factor of 40 dB at 0.01 Hz. Reducing the number of coils required and incorporating dynamic nulling should allow for greater take-up of this technology. Interactions of the coils with the high-permeability walls of the MSR were investigated using a method of images approach. Simulations show a degrading of field uniformity which was broadly consistent with measured values. These effects should be incorporated into future designs.

Magnetic Current Imaging Techniques: Comparative Case Studies

2004 ◽  
Author(s):  
Olivier Crépel ◽  
Philippe Descamps ◽  
Patrick Poirier ◽  
Romain Desplats ◽  
Philippe Perdu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Integrated Circuits ◽  
Case Studies ◽  
Flip Chip ◽  
Imaging Techniques ◽  
Optimal Domain ◽  
Magnetic Current ◽  
Comparative Case Studies ◽  
Current Flows

Abstract Magnetic field based techniques have shown great capabilities for investigation of current flows in integrated circuits (ICs). After reviewing the performances of SQUID, GMR (hard disk head technologies) and MTJ existing sensors, we will present results obtained on various case studies. This comparison will show the benefit of each approach according to each case study (packaged devices, flip-chip circuits, …). Finally we will discuss on the obtained results to classify current techniques, optimal domain of applications and advantages.

CALCULATION OF THE FLUX ASSOCIATED WITH THE ELECTRON'S SPIN ON THE BASIS OF THE MAGNETIC TOP MODEL

2002 ◽  
Vol 16 (04) ◽  
pp. 607-614 ◽  
Author(s):  
M. SAGLAM ◽  
B. BOYACIOGLU
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Current Loop ◽  
Circular Current

The flux associated with the electron's spin is calculated on a the basis of the magnetic top (spherical top) model which can be made equivalent to a circular current loop with radius R in x–y plane in the presence of a uniform magnetic field in z-direction. It is found that the flux associated with the electron's spin is exactly equal to +Φ0/2 for a spin down electron and -Φ0/2 spin up one.

scholarly journals A case study of the plasma in the magneto-sheath using the numerical magnetosheath-magnetosphere model and THEMIS measure-ments

2018 ◽  
Vol 145 ◽  
pp. 03004
Author(s):  
Polya Dobreva ◽  
Olga Nitcheva ◽  
Monio Kartalev
Keyword(s):  
Magnetic Field ◽  
Field Model ◽  
Specific Aspect ◽  
Plasma Parameters ◽  
Ion Density ◽  
Magnetic Field Model ◽  
Wind Spacecraft ◽  
The Mean ◽  
The Magnetic Field

This paper presents a case study of the plasma parameters in the magnetosheath, based on THEMIS measurements. As a theoretical tool we apply the self-consistent magnetosheath-magnetosphere model. A specific aspect of the model is that the positions of the bow shock and the magnetopause are self-consistently determined. In the magnetosheath the distribution of the velocity, density and temperature is calculated, based on the gas-dynamic theory. The magnetosphere module allows for the calculation of the magnetopause currents, confining the magnetic field into an arbitrary non-axisymmetric magnetopause. The variant of the Tsyganenko magnetic field model is applied as an internal magnetic field model. As solar wind monitor we use measurements from the WIND spacecraft. The results show that the model quite well reproduces the values of the ion density and velocity in the magnetosheath. The simlicity of the model allows calulations to be perforemed on a personal computer, which is one of the mean advantages of our model.

scholarly journals Scattering of field-aligned beam ions upstream of Earth's bow shock

2007 ◽  
Vol 25 (3) ◽  
pp. 785-799 ◽  
Author(s):  
A. Kis ◽  
M. Scholer ◽  
B. Klecker ◽  
H. Kucharek ◽  
E. A. Lucek ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Bow Shock ◽  
Ion Distribution ◽  
Parallel Side ◽  
Earth’S Bow Shock ◽  
High Mach ◽  
The Magnetic Field

Abstract. Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB) ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

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