scholarly journals Variations in ratio and correlation of solar magnetic fields in the Fe I 525.02 nm and Na I 589.59 nm lines according to Mount Wilson measurements during 2000–2012

2018 ◽  
Vol 4 (2) ◽  
pp. 11-34
Author(s):  
Елена Голубева ◽  
Elena Golubeva
Keyword(s):  
Magnetic Field ◽  
Solar Magnetic Field ◽  
Nonlinear Function ◽  
Spectral Lines ◽  
Magnetic Field Data ◽  
Field Magnitude ◽  
Mount Wilson Observatory ◽  
Magnetic Field Magnitude ◽  
Cross Calibration ◽  
Measured Magnetic Field

Variations in the solar magnetic-field ratio over 13 years are analyzed, relying on the comparison of simultaneous measurements in two spectral lines at the Mount Wilson Observatory. The ratio and correlation coefficient are calculated over the general working range of measured magnetic-field values and in various ranges of field magnitudes. We study variations in both the parameters. We have found the following tenden-cies: i) the parameters show changes with solar cycle in the general case; ii) their dependence on magnetic-field magnitude is a nonlinear function of time, and this is especially pronounced in the ratio behavior; iii) several separate ranges of the field magnitudes can be distin-guished based on the behavioral patterns of variations in the ratio. We discuss correspondences between these ranges and the known structural objects of the solar atmosphere. This leads to a conclusion that the dependence of the parameters on magnetic-field magnitude and time is connected with the variety of magnetic structural components and their cyclic rearrangements. The reported results may be useful for solving interpretation problems of solar magnetic-field meas-urements and for the cross-calibration of applicable instruments. They can also be used for tasks related to the creation of a uniform long temporal series of solar magnetic-field data from various sources.

scholarly journals Interinstrument calibration using magnetic field data from the flux-gate magnetometer (FGM) and electron drift instrument (EDI) onboard Cluster

2014 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
R. Nakamura ◽  
F. Plaschke ◽  
R. Teubenbacher ◽  
L. Giner ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Spin Axis ◽  
Electron Drift ◽  
Magnetic Field Data ◽  
Field Magnitude ◽  
Magnetic Field Magnitude ◽  
Flux Gate ◽  
Axis Offset ◽  
The Magnetic Field

Abstract. We compare the magnetic field data obtained from the flux-gate magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the electron drift instrument (EDI) onboard Cluster to determine the spin-axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 and 500 nT. Offset determination with the EDI–FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ∼ 0.6 nT was observed for Cluster 1 between July and October 2003. Using multipoint multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

scholarly journals Inter-instrument calibration using magnetic field data from Flux Gate Magnetometer (FGM) and Electron Drift Instrument (EDI) onboard Cluster

2013 ◽  
Vol 3 (2) ◽  
pp. 459-487
Author(s):  
R. Nakamura ◽  
F. Plaschke ◽  
R. Teubenbacher ◽  
L. Giner ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Spin Axis ◽  
Electron Drift ◽  
Magnetic Field Data ◽  
Field Magnitude ◽  
Magnetic Field Magnitude ◽  
Flux Gate ◽  
Axis Offset ◽  
The Magnetic Field

Abstract. We compare the magnetic field data obtained from the Flux-Gate Magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the Electron Drift Instrument (EDI) onboard Cluster to determine the spin axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 nT and 500 nT. Offset determination with the EDI-FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ~ 0.6 nT was observed between July and October 2003. Using multi-point multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

scholarly journals Cluster-C1 observations on the geometrical structure of linear magnetic holes in the solar wind at 1 AU

2010 ◽  
Vol 28 (9) ◽  
pp. 1695-1702 ◽  
Author(s):  
T. Xiao ◽  
Q. Q. Shi ◽  
T. L. Zhang ◽  
S. Y. Fu ◽  
L. Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Geometrical Structure ◽  
Occurrence Rate ◽  
Geometrical Shape ◽  
Magnetic Field Data ◽  
Magnetic Field Magnitude ◽  
The Relationship ◽  
Plasma Measurements ◽  
The Magnetic Field

Abstract. Interplanetary linear magnetic holes (LMHs) are structures in which the magnetic field magnitude decreases with little change in the field direction. They are a 10–30% subset of all interplanetary magnetic holes (MHs). Using magnetic field and plasma measurements obtained by Cluster-C1, we surveyed the LMHs in the solar wind at 1 AU. In total 567 interplanetary LMHs are identified from the magnetic field data when Cluster-C1 was in the solar wind from 2001 to 2004. We studied the relationship between the durations and the magnetic field orientations, as well as that of the scales and the field orientations of LMHs in the solar wind. It is found that the geometrical structure of the LMHs in the solar wind at 1 AU is consistent with rotational ellipsoid and the ratio of scales along and across the magnetic field is about 1.93:1. In other words, the structure is elongated along the magnetic field at 1 AU. The occurrence rate of LMHs in the solar wind at 1 AU is about 3.7 per day. It is shown that not only the occurrence rate but also the geometrical shape of interplanetary LMHs has no significant change from 0.72 AU to 1 AU in comparison with previous studies. It is thus inferred that most of interplanetary LMHs observed at 1 AU are formed and fully developed before 0.72 AU. The present results help us to study the formation mechanism of the LMHs in the solar wind.

Influence of Heating Temperature on the ΔЕ-Effect of Amorphous Fe75Si10B15 Wires

2014 ◽  
Vol 215 ◽  
pp. 264-267
Author(s):  
Andrey Semenov ◽  
Evgeniy Golygin ◽  
Alexey Gavriliuk ◽  
Alexander Mokhovikov ◽  
Alexander Gafarov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Inner Core ◽  
Heating Temperature ◽  
Amorphous Wire ◽  
Absolute Value ◽  
Tensile Stresses ◽  
Magnetoelastic Coupling ◽  
Field Magnitude ◽  
Magnetic Field Magnitude ◽  
Dc Current

In the present work we have investigated the influence of the thermocycling on the magnetoelastic parameters (the ΔЕ-effect) of amorphous Fe75Si10B15 wires, which had been pretreated by dc current j with simultaneous applying of the tensile stresses σ. It was figured out the ΔЕ-effect behavior depends strongly on pretreatment circumstances. Namely, we have got the maximum absolute value of the ΔЕ-effect shifted into direction of the higher magnetic field magnitude at j<39 MA/m2 and σ<127 MPa. In addition, the negative ΔЕ-effect was not observed for samples, pretreated at j≥45MА/m2 or σ≥128 MPa . The features of such a behavior of the ΔЕ-effect were explained in terms of the magnetoelastic coupling between the inner core and the outer shell of the amorphous wire.

The PTB electromagnetic undulator for BESSY II

1998 ◽  
Vol 5 (3) ◽  
pp. 451-452 ◽  
Author(s):  
R. Klein ◽  
J. Bahrdt ◽  
D. Herzog ◽  
G. Ulm
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Tuning Range ◽  
Period Length ◽  
Design Parameters ◽  
Magnetic Field Data ◽  
Electromagnetic Design ◽  
Special Mode ◽  
Main Design ◽  
Measured Magnetic Field

The Physikalisch-Technische Bundesanstalt (PTB) will operate an electromagnetic undulator designed for radiometry at the BESSY II storage ring. The undulator has a period length of 180 mm, 21 full periods and a maximum magnetic induction of 0.46 T, resulting in a tuning range of the first harmonic from 5 to 150 eV at 1.7 GeV electron energy. Moreover, the electromagnetic design allows the undulator to be operated in a special mode with the period length doubled to 360 mm, thus accordingly shifting the tuning range to lower energies. The main design parameters of the undulator for radiometric applications, as well as measured magnetic field data, are presented.

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