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
    High mass resolution isochronous time-of-flight spectrograph for three-dimensional space plasma measurements (abstract) : Eighth topical conference on high—temperature plasma diagnostics (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 3150-3150 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: By combining a toroidal electrostatic analyzer with a novel cylindrically symmetric isochronous time-of-flight mass spectrometer, we have developed an instrument that simultaneously determines the three-dimensional distribution function of ions and differentiates species. The ion mass is determined to high resolution (M/ΔM(approximately-greater-than)50) from the time of flight within a harmonic field configuration defined by hyperboloid equipotential surfaces. A second conventional time-of-flight channel makes use of particles leaving the thin entrance foil as neutrals. An additional solid state detector in which the neutrals are stopped allows the total energy and thereby the ionic charge of the incident ions to be determined as well. Information from the neutral and the ion channels can be combined to determine the total mass of an incident molecular ion and the mass of one atomic fragment. This also removes the ambiguity between molecular ions and isotopic species of the same mass. A laboratory prototype has been used to demonstrate the feasibility of the principle of operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High mass resolution isochronous time-of-flight spectrograph for three-dimensional space plasma measurements (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 3609-3612 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: By combining a toroidal electrostatic analyzer with a novel cylindrically symmetric isochronous time-of-flight mass spectrometer, we have developed an instrument that simultaneously determines the three-dimensional distribution function of ions and differentiates species. The ion mass is determined to high resolution (M/ΔM(approximately-greater-than)50) from the time of flight within a harmonic field configuration defined by hyperboloid equipotential surfaces. A second conventional time-of-flight channel makes use of particles leaving the thin entrance foil as neutrals. An additional solid state detector in which the neutrals are stopped allows the total energy and thereby the ionic charge of the incident ions to be determined as well. Information from the neutral and the ion channels can be combined to determine the total mass of an incident molecular ion and the mass of one atomic fragment. This also removes the ambiguity between molecular ions and isotopic species of the same mass. A laboratory prototype has been used to demonstrate the feasibility of the principle of operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141580
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Extended magnetic reconnection at the Earth's magnetopause from detection of bi-directional jets (2000)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 404 (2000), S. 848-850 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Magnetic reconnection is a process that converts magnetic energy into bi-directional plasma jets; it is believed to be the dominant process by which solar-wind energy enters the Earth's magnetosphere. This energy is subsequently dissipated by magnetic storms and aurorae. Previous ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/35009050
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The influence of the plasma inhomogeneity on the critical velocity phenomenon (1980)
    Springer
    Astrophysics and space science 72 (1980), S. 211-221 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The phenomenon of a critical ionization velocity is discussed under the aspect of experimentally measured inhomogeneities. The difficulties inherent in homogeneous plasma models on the phenomenon are shown. A simple sheath model is presented which can be compared with the local plasma parameters measured in a rotating plasma device. The origin of the observed turbulent heating is attributed to a modified two-stream instability occurring in the sheath under discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00642180
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    First Solar EUV Irradiances Obtained from SOHO by the Celias/Sem (1998)
    Springer
    Solar physics 177 (1998), S. 161-173 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The first results obtained with the Solar EUV Monitor (SEM), part of the Charge, Element, and Isotope Analysis System (CELIAS) instrument, aboard the SOlar and Heliospheric Observatory (SOHO) satellite are presented. The instrument monitors the full-disk absolute value of the solar Heii irradiance at 30.4 nm, and the full-disk absolute solar irradiance integrated between 0.1 nm and 77 nm. The SEM was first turned on December 15, 1995 and obtained ‘first light’ on December 16, 1995. At this time the SOHO spacecraft was close to the L-1 Lagrange point, 1.5 × 106 km from the Earth towards the Sun. The data obtained by the SEM during the first four and a half months of operation will be presented. Although the period of observation is near solar minimum, the SEM data reveal strong short-term solar irradiance variations in the broad-band, central image channel, which includes solar X-ray emissions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004929011427
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) and the Data Processing Unit (S3DPU) for SWICS, SWIMS and SEPICA (1998)
    Springer
    Space science reviews 86 (1998), S. 449-495 
    Details
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) is the main instrument on the Advanced Composition Explorer (ACE) to determine the ionic charge states of solar and interplanetary energetic particles in the energy range from ≈0.2 MeV nucl−1 to ≈5 MeV charge−1. The charge state of energetic ions contains key information to unravel source temperatures, acceleration, fractionation and transport processes for these particle populations. SEPICA will have the ability to resolve individual charge states and have a substantially larger geometric factor than its predecessor ULEZEQ on ISEE-1 and -3, on which SEPICA is based. To achieve these two requirements at the same time, SEPICA is composed of one high-charge resolution sensor section and two low- charge resolution, but large geometric factor sections. The charge resolution is achieved by the focusing of the incoming ions, through a multi-slit mechanical collimator, deflection in an electrostatic analyzer with a voltage up to 30 kV, and measurement of the impact position in the detector system. To determine the nuclear charge (element) and energy of the incoming ions, the combination of thin-window flow-through proportional counters with isobutane as counter gas and ion-implanted solid state detectors provide for 3 independent ΔE (energy loss) versus E (residual energy) telescopes. The multi-wire proportional counter simultaneously determines the energy loss ΔE and the impact position of the ions. Suppression of background from penetrating cosmic radiation is provided by an anti-coincidence system with a CsI scintillator and Si-photodiodes. The data are compressed and formatted in a data processing unit (S3DPU) that also handles the commanding and various automatted functions of the instrument. The S3DPU is shared with the Solar Wind Ion Charge Spectrometer (SWICS) and the Solar Wind Ion Mass Spectrometer (SWIMS) and thus provides the same services for three of the ACE instruments. It has evolved out of a long family of data processing units for particle spectrometers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005084014850
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Direct observation of He + pick-up ions of interstellar origin in the solar wind (1985)
    [s.l.] : Nature Publishing Group
    Nature 318 (1985), S. 426-429 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Singly-ionized helium with a velocity distribution extending up to double the solar wind velocity has been detected in interplanetary space. This distribution unambiguously determines the source: interstellar neutrals, ionized and accelerated in the solar wind. The observed significant flux ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/318426a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Determination of interstellar pickup ion distributions in the solar wind with SOHO and Cluster (1996)
    Springer
    Annales geophysicae 14 (1996), S. 492-496 
    Details
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Over the last 10 years, the experimental basis for the study of the local interstellar medium has been substantially enhanced by the direct detection of interstellar pickup ions and of interstellar neutral helium within the heliosphere. Pickup ions can be studied for a wide range of interstellar species. However, currently the accuracy of the method to determine the parameters of the interstellar medium, namely neutral density, temperature and relative velocity, is hampered by two problems: (1) In most cases the crucial ionization rates are not available from simultaneous measurements and (2) the transport of the pickup ions in the interplanetary medium substantially modifies the measured spatial distribution of the ions. In this study we will discuss how the enhanced capabilities of the instrumentation on SOHO and Cluster in combination with ongoing efforts to model the pickup ion distributions will lead to a significant improvement over the coming years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-996-0492-x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Testing electric field models using ring current ion energy spectra from the Equator-S ion composition (ESIC) instrument (1999)
    Springer
    Annales geophysicae 17 (1999), S. 1611-1621 
    Details
    ISSN: 0992-7689
    Keywords: Magnetospheric physics (energetic particles trapped ; plasma convection ; storms and substorms)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract During the main and early recovery phase of a geomagnetic storm on February 18, 1998, the Equator-S ion composition instrument (ESIC) observed spectral features which typically represent the differences in loss along the drift path in the energy range (5–15 keV/e) where the drift changes from being E × B dominated to being gradient and curvature drift dominated. We compare the expected energy spectra modeled using a Volland-Stern electric field and a Weimer electric field, assuming charge exchange along the drift path, with the observed energy spectra for H+ and O+. We find that using the Weimer electric field gives much better agreement with the spectral features, and with the observed losses. Neither model, however, accurately predicts the energies of the observed minima.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-999-1611-2
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Interaction of interstellar pick-up ions with the solar wind (1988)
    Springer
    Astrophysics and space science 144 (1988), S. 487-505 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The interaction of interstellar pick-up ions with the solar wind is studied by comparing a model for the velocity distribution function of pick-up ions with actual measurements of He+ ions in the solar wind. The model includes the effects of pitch-ang'e diffusion due to interplanetary Alfvén waves, adiabatic deceleration in the expanding solar wind and the radial variation of the source function. It is demonstrated that the scattering mean free path is in the range ≤0.1 AU and that energy diffusion can be neglected as compared with adiabatic deceleration. The effects of adiabatic focusing, of the radial variation of the neutral density and of a variation of the solar wind velocity with distance from the Sun are investigated. With the correct choice of these parameters we can model the measured energy spectra of the pick-up ions reasonably well. It is shown that the measured differential energy density of the pick-up ions does not vary with the solar wind velocity and the direction of the interplanetary magnetic field for a given local neutral gas density and ionization rate. Therefore, the comparison of the model distributions with the measurements leads to a quantitative determination of the local interstellar gas density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00793200
    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...