scholarly journals 3-Dimensional High-Resolution Solar Spectro-Polarimetry

1995 ◽  
Vol 149 ◽  
pp. 193-194
Author(s):  
Reiner Volkmer
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Narrow Band ◽  
The Sun ◽  
Two Dimensional ◽  
Vacuum Tower ◽  
3 Dimensional ◽  
Fabry Perot ◽  
Spatial Dimensions ◽  
The Magnetic Field

AbstractIn order to obtain information on the magnetic field on the sun in two spatial dimensions, a spectro-polarimeter of high spatial, spectral, and temporal resolution was built in the German Vacuum Tower Telescope (VTT) at the Observatorio del Teide/Tenerife. The two-dimensional spectrometer in the VTT, using a Universal Birefringent Filter (UBF) and a Fabry-Perot Interferometer (FPI) to obtain narrow-band nltergrams with a spectral resolution of the order of 3.105 (approx. 22 mÅ at CE5; at 6303 Å) and a spatial resolution of 0.2 arcsec/pixel (Bendlin et al. 1992, Bendlin and Volkmer 1993), was extended to work as a spectropolarimeter for measuring Stokes-I and Stokes-V profiles.

scholarly journals A Two-Dimensional Spectrometer for Solar Observation and its recent modifications

1995 ◽  
Vol 149 ◽  
pp. 188-192
Author(s):  
Cornelia Bendlin
Keyword(s):  
Magnetic Field ◽  
Solar Magnetic Field ◽  
Narrow Band ◽  
Solar Observation ◽  
Two Dimensional ◽  
Vacuum Tower ◽  
Additional Information ◽  
Combined Use ◽  
Wide Range ◽  
Fabry Perot

AbstractThe instrument presented here is based on the combined use of a Universal Birefringent Filter (UBF) and a Fabry-Perot Interferometer (FPI) to obtain narrow-band filtergrams with a CCD. Scanning through a Fraunhofer line with a sufficient number of wavelength settings is accomplished within a few seconds by tuning only the FPI. The two-dimensional spectrometer in the German Vacuum Tower Telescope (VTT)/Tenerife was used to take observations of high spatial, spectral, and temporal resolution, yielding a wide range of results. Since recently, additional information on the solar magnetic field is obtained with it.

scholarly journals Magnetic field in active regions of the sun at coronal heights

2008 ◽  
Vol 4 (S257) ◽  
pp. 349-352
Author(s):  
V. M. Bogod ◽  
L. V. Yasnov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Vertical Structure ◽  
Active Regions ◽  
Magnetic Flux Tube ◽  
Microwave Range ◽  
The Sun ◽  
Two Dimensional ◽  
Radio Waves ◽  
The Magnetic Field

AbstractA method is developed for estimation of the vertical structure of the magnetic field in active regions using multi-wave spectral-polarization measurements of radio waves which gives not only the dependence of magnetic field strength on height but also determines two-dimensional form of a magnetic flux tube, emitted in the microwave range of wavelengths.

scholarly journals Magnetically assisted explosions of weakly magnetized stars

2017 ◽  
Vol 12 (S331) ◽  
pp. 125-130
Author(s):  
Hidetomo Sawai ◽  
Shoichi Yamada
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
High Resolution ◽  
Stellar Evolution ◽  
Positive Impact ◽  
Core Collapse ◽  
Two Dimensional ◽  
Magnetorotational Instability ◽  
The Magnetic Field ◽  
Large Angular Momentum

AbstractWe carried out high resolution simulations of weakly-magnetized core-collapse supernovae in two-dimensional axisymmetry in order to see the influence of the magnetic field and rotation on the explosion. We found that the magnetic field amplified by magnetorotational instability (MRI) has a great positive impact on the explosion by enhancing the neutrino heating, provided that the progenitor has large angular momentum close to the highest value found in stellar evolution calculations. We also found that even for progenitors neither involving strong magnetic flux nor large angular momentum, the magnetic field is greatly amplified by the convection aand rotation, and this leads to the boost of the explosion again by enhancing the neutrino heating.

scholarly journals The magnetic field and its effects on the solar atmosphere in high resolution

2006 ◽  
Vol 2 (14) ◽  
pp. 30-40
Author(s):  
Alan M. Title
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Solar Interior ◽  
The Sun ◽  
Magnetic Field Effects ◽  
Entire Surface ◽  
Subsurface Flows ◽  
Outer Atmosphere ◽  
Multiple Cycles ◽  
The Magnetic Field

AbstractThe Sun's magnetic field is produced throughout the solar interior; it emerges and is dispersed by surface and subsurface flows, and then expands above the surface to dominate the structure of the corona. To resolve the effects of the magnetic field it is necessary to image the interior and measure its rotation and flow systems; track the responses of the magnetic fields to flows in the surface; and to follow the evolution of structures in the corona. Because the Sun is dynamic both high spatial and temporal resolution are essential. Because the Sun's magnetic field effects encompass the entire spherical exterior, the entire surface and outer atmosphere must be mapped. And because the magnetic field is cyclic high-resolution observations must be maintained over multiple cycles.

scholarly journals Digital Videomagnetograms in Real Time

1971 ◽  
Vol 43 ◽  
pp. 44-50 ◽  
Author(s):  
Thomas J. Janssens ◽  
Neal K. Baker
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Magnetic Fields ◽  
Real Time ◽  
Temporal Resolution ◽  
Optical Filter ◽  
Line Of Sight ◽  
The Sun ◽  
The Magnetic Field

The Aerospace – NASA Videomagnetograph began operation one month ago, two years after components were ordered and construction began. The design grew out of a desire to obtain magnetic fields in real time using an optical filter. The aim was to study and analyze magnetic configurations and changes, quantitatively if possible, with high spatial and temporal resolution and as much sensitivity as possible. This instrument is restricted to the line-of-sight component of the magnetic field and is primarily intended for high resolution studies of selected regions of the sun. The rationale behind our approach is shown in the next section and the design details in the following.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

A Super-High-Resolution HVEM (H-1500) Newly Installed in NIRIM

1990 ◽  
Vol 48 (1) ◽  
pp. 142-143
Author(s):  
S. Horiuchi ◽  
Y. Matsui
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Chromatic Aberration ◽  
Inorganic Materials ◽  
Electron Gun ◽  
Resolving Power ◽  
National Budget ◽  
Voltage Electron ◽  
Specimen Holder ◽  
The Magnetic Field

A new high-voltage electron microscope (H-1500) specially aiming at super-high-resolution (1.0 Å point-to-point resolution) is now installed in National Institute for Research in Inorganic Materials ( NIRIM ), in collaboration with Hitachi Ltd. The national budget of about 1 billion yen including that for a new building has been spent for the construction in the last two years (1988-1989). Here we introduce some essential characteristics of the microscope.(1) According to the analysis on the magnetic field in an electron lens, based on the finite-element-method, the spherical as well as chromatic aberration coefficients ( Cs and Cc ). which enables us to reach the resolving power of 1.0Å. have been estimated as a function of the accelerating As a result of the calculaton. it was noted that more than 1250 kV is needed even when we apply the highest level of the technology and materials available at present. On the other hand, we must consider the protection against the leakage of X-ray. We have then decided to set the conventional accelerating voltage at 1300 kV. However. the maximum accessible voltage is 1500 kV, which is practically important to realize higher voltage stabillity. At 1300 kV it is expected that Cs= 1.7 mm and Cc=3.4 mm with the attachment of the specimen holder, which tilts bi-axially in an angle of 35° ( Fig.1 ). In order to minimize the value of Cc a small tank is additionally placed inside the generator tank, which must serve to seal the magnetic field around the acceleration tube. An electron gun with LaB6 tip is used.

scholarly journals THE ENERGY EIGENVALUES OF THE TWO DIMENSIONAL HYDROGEN ATOM IN A MAGNETIC FIELD

2006 ◽  
Vol 15 (06) ◽  
pp. 1263-1271 ◽  
Author(s):  
A. SOYLU ◽  
O. BAYRAK ◽  
I. BOZTOSUN
Keyword(s):  
Magnetic Field ◽  
Hydrogen Atom ◽  
Iteration Method ◽  
Weak Magnetic Field ◽  
The Other ◽  
Asymptotic Iteration Method ◽  
Iterative Approach ◽  
Two Dimensional ◽  
Energy Eigenvalues ◽  
The Magnetic Field

In this paper, the energy eigenvalues of the two dimensional hydrogen atom are presented for the arbitrary Larmor frequencies by using the asymptotic iteration method. We first show the energy eigenvalues for the case with no magnetic field analytically, and then we obtain the energy eigenvalues for the strong and weak magnetic field cases within an iterative approach for n=2-10 and m=0-1 states for several different arbitrary Larmor frequencies. The effect of the magnetic field on the energy eigenvalues is determined precisely. The results are in excellent agreement with the findings of the other methods and our method works for the cases where the others fail.

Detection of a change in the North-South ratio of count rates of particles of high-energy cosmic rays during a change in the polarity of the magnetic field of the Sun

JETP Letters ◽  
2015 ◽  
Vol 101 (4) ◽  
pp. 228-231
Author(s):  
A. V. Karelin ◽  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
High Energy ◽  
The Sun ◽  
High Energy Cosmic Rays ◽  
The North ◽  
The Magnetic Field
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