THE APPLICATION OF A FLUXGATE MAGNETOMETER TO AN AUTOMATIC ELECTRONIC DEGAUSSING SYSTEM

1961 ◽  
Vol 39 (9) ◽  
pp. 1357-1368 ◽  
Author(s):  
R. L. Graham ◽  
J. S. Geiger
Keyword(s):  
Magnetic Field ◽  
Magnetic Storm ◽  
Uniform Magnetic Field ◽  
Regulation System ◽  
Fluxgate Magnetometer ◽  
Current Regulation ◽  
Correction Signal ◽  
Electronic Circuitry ◽  
The Earth

The three-component fluxgate magnetometer developed by Serson has been adapted to provide continuous correction signals to the degaussing system of the Chalk River iron-free β-ray spectrometer. Improved electronic circuitry has been developed for the magnetometer which minimizes the zero error and reduces to < 10−4 gauss long-term drift caused by component aging. The degaussing coil arrangement used to generate uniform magnetic field components opposite to those of the earth is indicated and the current regulation system is described briefly. The method in which the magnetometer correction signal is introduced into the current regulators is shown and an example is given of the performance of this degaussing system during a magnetic storm.

scholarly journals Rheological Properties of the Erythrocytes in Weakened Static Magnetic Field of the Earth In vitro Study

2019 ◽  
pp. 1-12
Author(s):  
L. N. Katiukhin
Keyword(s):  
Magnetic Field ◽  
Rheological Properties ◽  
In Vitro Study ◽  
Body Volume ◽  
Osmotic Gradient ◽  
Long Term Storage ◽  
The Earth ◽  
Average Body

Background: The magnetobiological effect of the weakened magnetic field of the Earth is of interest due to the consequences of the long stay of astronauts in space. Objective: The rheological properties of erythrocytes in a weakened magnetic field of the Earth are investigated. Methods: Osmotic gradient ektacytometry, aggregometry. Results: A study of the rheological properties of erythrocytes of blood rats in vitro, exposed at a temperature of 0°C in a natural and weakened magnetic field of the Earth, was carried out. It is established that a weakened magnetic field leads to a decrease in the rate of hemolysis, the average body volume, transformation, and decrease in the specific surface of the erythrocyte, potentiates the weakening of the deformation and aggregation properties. Conclusions: The results of the work should be taken into account not only to predict the rheological behavior of the blood system when the natural magnetic field is weakened but also to optimize the conditions for the long-term storage of donor blood.

scholarly journals 33. The present state of the corpuscular theory of magnetic storms

1958 ◽  
Vol 6 ◽  
pp. 295-311
Author(s):  
V. C. A. Ferraro
Keyword(s):  
Magnetic Field ◽  
Magnetic Storm ◽  
Ring Current ◽  
Plane Surface ◽  
Magnetic Storms ◽  
Main Phase ◽  
Polar Regions ◽  
Stream Surface ◽  
The Earth ◽  
The Magnetic Field

The evidence in favour of a corpuscular theory of magnetic storms is briefly reviewed and reasons given for believing that the stream must be neutral but ionized and carry no appreciable current. It is shown that under suitable conditions the stream is able to pass freely through a solar magnetic field; the stream may also be able to carry away with it a part of this field. However, because of geometrical broadening of the stream during its passage from the sun to the earth, the magnetic field imprisoned in the gas may be wellnigh unobservable near the earth.The nature, composition and dimensions of the stream near the earth are discussed and it is concluded that on arrival the stream will present very nearly a plane surface to the earth if undistorted by the magnetic field.Because of its large dimensions, the stream will behave as if it were perfectly conducting. During its advance in the earth's magnetic field the currents induced in the stream will therefore be practically confined to the surface. The action of the magnetic field on this current is to retard the surface of the stream which being highly distortible will become hollowed out. Since the stream surface is impervious to the interpenetration of the magnetic tubes of force, these will be compressed in the hollow space. The intensity of the magnetic field is thereby increased and this increase is identified with the beginning of the first phase of a magnetic storm. This increase will be sudden, as observed, owing to the rapid approach of the stream to the earth.The distortion of the stream surface is discussed and it is pointed out that two horns will develop on the surface, one north and the other south of the geomagnetic equator. Matter pouring through these two horns will find its way to the polar regions.The main phase of a magnetic storm seems most simply explained as due to a westward ring-current flowing round the earth in its equatorial plane. Under suitable conditions such a ring-current would be stable if once set up. The mode of formation of the ring is, however, largely conjectural. The possibility that the main phase may be of atmospheric origin is also briefly considered. It is shown that matter passing through the two horns to the polar regions could supply the energy necessary for the setting up of the field during the main phase. The magnetic evidence in favour of such a hypothesis, however, seems wanting.

Electric currents in the ionosphere - The conductivity

1953 ◽  
Vol 246 (913) ◽  
pp. 281-294 ◽  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Uniform Magnetic Field ◽  
Hall Current ◽  
Effective Conductivity ◽  
Polarization Field ◽  
Dynamo Theory ◽  
Electric Currents ◽  
Narrow Strip ◽  
The Earth

An earlier suggestion by Martyn that the effective conductivity of the ionosphere in the dynamo theory is enhanced by polarization of the Hall current is examined in quantitative detail. General expressions are given for the conductivities of a thin ionized sheet oriented at an angle to a uniform magnetic field. The effective conductivity of such a (spherical) sheet surrounding the earth is shown to be greater than either the Pedersen or the Hall conductivities. The variation of conductivity with latitude is calculated for the ionospheric level of maximum effective conductivity. Consideration is given to the height-integrated conductivity of the actual ionosphere, and effective values deduced. It is shown that the F 2 region will move bodily under the influence of the electric field from lower regions, thereby reducing its ability to shunt the Hall polarization field. The effective conductivity over most of the earth is found to be sufficient to satisfy Stewart’s dynamo theory. In a narrow strip at the equator the conductivity is enhanced, thereby accounting for the anomalously large magnetic variations found to occur in these regions.

The strength of the Earth Magnetic field around the Cretaceous Normal Superchron: new data from Costa Rica

2020 ◽  
Author(s):  
Anita Di Chiara ◽  
Lisa Tauxe ◽  
Hubert Staudigel ◽  
Fabio Florindo ◽  
Yongjae Yu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Costa Rica ◽  
Selection Criteria ◽  
Pillow Lava ◽  
Dipole Field ◽  
Dipole Strength ◽  
The Earth ◽  
Earth Magnetic Field ◽  
The Magnetic Field

&lt;p&gt;There has been an increasing effort toward the constraint of the average and long-term variability of the magnetic field strength, fundamental to better understand the characteristics and behaviour of the geomagnetic dipole field. Nonetheless, open questions remain about the value of the average dipole field, the relation between dipole strength and excursion reversal. Indeed, depending on the criteria adopted to analyse the current database, different long-term average values can be found, leading to different answers. The reason for the open debate can explained with the limited amount of data from key time intervals and geographical areas, due to both to complexities behind the method to obtain absolute paleointensities (several methods and experimental designs, selection criteria, high failure rate, etc..) and suitable materials.&lt;/p&gt;&lt;p&gt;Here, we focus on the Cretaceous Normal Superchron, a long period, from approximately 121 to 83 Ma, when the magnetic field was characterised by a stable polarity. Yet, few paleointensity data were available so far. In this study, we present new results from 48 Submarine Basaltic Glass sites from pillow lava margins, sampled on the upper crust sequence of the Costa Rica Ophiolite. Ar/Ar ages along with biostratigraphic age constraints from previous studies indicate ages ranging from from 139 to 94 Ma. After 473 samples were measured using the IZZI-Thellier protocol and analysed using strict selection criteria, 13 sites between 109 and 133 Ma gave reliable and robust results. Our new results from Costa Rica suggest that the strength of the Earth Magnetic field during CNS, 70.2 &amp;#177; 21 ZAm&lt;sup&gt;2&lt;/sup&gt; &amp;#160;are slightly lower than the pre-CNS and also lower than, for instance, at Troodos Ophiolite (81 &amp;#177;&amp;#160;43 ZAm&lt;sup&gt;2&lt;/sup&gt;; Tauxe and Staudigel 2004), consistent with the observations by Tauxe (2006) of an average dipole moment being substantially less than the present day value.&lt;/p&gt;

scholarly journals Interplanetary External Driven Quasidynamo as the Origin of Geomagnetic Jerks Correlated with Length of Day and Gravity Anomaly

2018 ◽  
Vol 48 (1) ◽  
pp. 23-74
Author(s):  
Mohsen Lutephy
Keyword(s):  
Magnetic Field ◽  
Secular Variation ◽  
Coupling Effect ◽  
Length Of Day ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Induced Currents ◽  
Geomagnetic Jerks ◽  
Field Oscillation

Abstract We report phenomenological inevitable correlation between the Sun’s magnetic field oscillation through the Earth and the Jupiter, with sinusoidal geomagnetic jerks observed at the Earth, additionally aligned with the gravity and length of day sinusoidal variations and we observe too that the Sun and Jovian planets alignments with Jupiter are origin of the observable abrupt geomagnetic jerks whether historical or new, and experimental results demonstrate a possible explanation on the base of the planetary induced currents upon the metallic liquid cores of the planets upon the varying external magnetic fields as the source of heat flows continued by frictional turbulent and convectional fluid fluxes, amplified and expanding by the Earth magnetic field and observations are showing too that it should be an electric coupling effect between metallic cores of the planets, under the magnetic field oscillation so that Jupiter conductive metallic region interacts with Earth metallic core while the Sun’s magnetic field is oscillating through the Jupiter and we see a relation between secular variation of the Earth’s magnetic field and long term trend of 5.9-years signals as a new method to measure geomagnetic secular variation by LOD signals.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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