ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Magnetic field measurements based on the Zeeman splitting of forbidden transitions (1985)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 56 (1985), S. 855-856 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The measurement of the poloidal magnetic field in a tokamak plasma from the Zeeman splitting and polarization of the magnetic dipole radiation from heavy ions is discussed. When viewed from a direction perpendicular to the toroidal field, the effect of the poloidal field on the circularly polarized radiation is detectable using a photoelectric polarimeter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1138071
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Simultaneous radio scattering and white light observations of a coronal transient (1982)
    [s.l.] : Nature Publishing Group
    Nature 300 (1982), S. 157-159 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Figure 1 shows four coronal images obtained with the Solwind instrument6 on 24 October, 1979. The upper images were taken at 0316 and 1258 UT while the lower ones are difference images formed by subtracting the images at 0536 and 0804 UT from that at 0316 UT to show the changes that had taken place ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/300157a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Coronagraphic observations of two new sungrazing comets (1982)
    [s.l.] : Nature Publishing Group
    Nature 300 (1982), S. 239-242 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Our observations were obtained with the Naval Research Laboratory's Earth-orbiting SOLWIND coronagraph. This instrument has been operating routinely on the US Air Force Space Test Program satellite, P78-1, since March 1979. Its broadband (4,100-6,350 A) images show a Sun-centred annular field of ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/300239a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Latitudinal distribution of solar-wind speed from magnetic observations of the Sun (1990)
    [s.l.] : Nature Publishing Group
    Nature 347 (1990), S. 439-444 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Empirical studies suggest a close relationship between the solar-wind speed near the Earth and the magnetic structure of the solar corona. The correlation can be used to infer the latitudinal distribution of wind speed at different phases of the sunspot cycle, and to identify the sources of fast, ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/347439a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Large-scale coronal heating by the small-scale magnetic field of the Sun (1998)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 394 (1998), S. 152-154 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Magnetic fields play a crucial role in heating the outer atmospheres of the Sun and Sun-like stars, but the mechanisms by which magnetic energy in the photosphere is converted to thermal energy in the corona remain unclear. Observations show that magnetic fields emerge onto the solar surface as ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/28108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Observations of coronal structure during sunspot maximum (1982)
    Springer
    Space science reviews 33 (1982), S. 219-231 
    Details
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This paper presents some of the results that have been obtained from the Kitt Peak observations of coronal holes and the NRL observations of coronal transients during the recent years near sunspot maximum (1979–1981). On the average, low-latitude coronal holes of comparable size contained 3 times more flux near sunspot maximum than near the previous minimum. In the outer corona, transients occurred at the observed rate of at least 2 per day, and quiet conditions persisted during less than 15 % of the observed days. We describe a sample of the more than 800 events that we have observed so far, including the observation of a comet apparently colliding with the Sun.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213255
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The effect of newly erupting flux on the polar coronal holes (1989)
    Springer
    Solar physics 119 (1989), S. 323-340 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract He i 10830 Å images show that early in sunspot cycles 21 and 22, large bipolar magnetic regions strongly affected the boundaries of the nearby polar coronal holes. East of each eruption, the hole boundary immediately contracted poleward, leaving a band of enhanced helium network. West of the eruption, the boundary remained diffuse and gradually expanded equatorward into the leading, like-polarity part of the bipolar magnetic region. Comparisons between these observations and simulations based on a current-free coronal model suggest that: (1) The Sun's polar magnetic fields are confined to relatively small caps of high average field strength, apparently by a poleward meridional flow. (2) The enhanced helium network at high latitude marks the location of relatively strong polar fields that have become linked to the newly erupted bipolar region in that hemisphere. (3) The distortion of the polar-hole boundary is accompanied by a corresponding distortion of the equatorial neutral sheet in the outer corona, in which the amount of warping depends on the magnitude of the erupted flux relative to the strength of the Sun's polar magnetic fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00146182
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Mechanisms for the rigid rotation of coronal holes (1988)
    Springer
    Solar physics 117 (1988), S. 359-389 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We show that the rotation of coronal holes can be understood in terms of a current-free model of the coronal magnetic field, in which holes are the footpoint locations of open field lines. The coronal field is determined as a function of time by matching its radial component to the photospheric flux distribution, whose evolution is simulated including differential rotation, supergranular diffusion, and meridional flow. We find that ongoing field-line reconnection allows the holes to rotate quasi-rigidly with their outer-coronal extensions, until their boundaries become constrained by the neutral line of the photospheric field as it winds up to form stripes of alternating magnetic polarity. This wind-up may be significantly retarded by a strong axisymmetric field component which forces the neutral line to low latitudes; it is also gradually halted by the cross-latitudinal transport of flux via supergranular diffusion and a poleward bulk flow. We conclude that a strong axisymmetric field component is responsible for the prolonged rigid rotation of large meridional holes during the declining phase of the sunspot cycle, but that diffusion and flow determine the less rigid rotation observed near sunspot maximum, when the holes corotate with their confining polarity stripes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00147253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Implications of a strongly peaked polar magnetic field (1989)
    Springer
    Solar physics 124 (1989), S. 1-13 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Using the flux-transport equation in the absence of sources, we study the relation between a highly peaked polar magnetic field and the poleward meridional flow that concentrates it. If the maximum flow speed ν m greatly exceeds the effective diffusion speed κ/R, then the field has a quasi-equilibrium configuration in which the poleward convection of flux via meridional flow approximately balances the equatorward spreading via supergranular diffusion. In this case, the flow speed ν(θ) and the magnetic field B(θ) are related by the steady-state approximation ν(θ) ≃ (κ/R)B′(θ)/B(θ) over a wide range of colatitudes θ from the poles to midlatitudes. In particular, a general flow profile of the form sin p θ cos q θ which peaks near the equator (q ≪ p) will correspond to a cos n θ magnetic field at high latitudes only if p = 1 and ν m = n κ/R. Recent measurements of n ∼ 8 and κ ∼ 600 km2 s−1 would then give ν m ∼ 7 m s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00146515
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Simultaneous measurements of magnetic fields and brightness fields using a 4-image spectroheliograph (1970)
    Springer
    Solar physics 12 (1970), S. 69-83 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The use of an auxiliary beamsplitter with the Kitt Peak 15-foot spectroheliograph permits spectroheliograms to be taken simultaneously in 4 identical images of the sun. By using two of these images for a Zeeman spectroheliogram, a third image for a Fei λ4071 spectroheliogram, and the fourth image for a 6107Å continuum spectroheliogram, simultaneous measurements of magnetic fields and brightness fields have been obtained. Within the limits of intensity variations imposed by doppler shifts and brightness fluctuations of the continuum, a quantitative relation does exist between the measured values of brightness and magnetic field strength of the photospheric network. For intensities measured +0.12 Å from the core of Fei λ4071, this relation is ln(1 +ΔI/I) = α¦B ∥¦, whereB ∥ refers to the component of magnetic field normal to the solar surface,ΔI/I is the fractional excess of brightness of the magnetic regions relative to the brightness of non-magnetic regions, and α = (6±2)%/100 gauss.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02276566
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...