Now showing items 1-9 of 9

    • The charge-sign dependent effect in the solar modulation of cosmic rays 

      Potgieter, M.S. (Elsevier, 2014)
      The centennial anniversary of the discovery of cosmic rays was in 2012. Since this discovery considerable progress has been made on several aspects related to galactic cosmic rays in the heliosphere. It is known that they ...
    • Cosmic rays in the inner heliosphere: insights from observations, theory and models 

      Potgieter, M.S. (Springer, 2011)
      The global modulation of galactic cosmic rays in the inner heliosphere is determined by four major mechanisms: convection, diffusion, particle drifts (gradient, curvature and current sheet drifts), and adiabatic energy ...
    • Is the highest cosmic-ray flux yet to come? 

      Strauss, R.D.; Potgieter, M.S. (Springer, 2014)
      The recent 2009 solar-minimum period was characterized by a record-setting high Galactic cosmic-ray flux observed at Earth. This, along with the unexpected low heliospheric magnetic-field magnitude, caused this period ...
    • A local interstellar spectrum for galactic electrons 

      Potgieter, M.S.; Nndanganeni, R.R. (Elsevier, 2013)
      A heliopause spectrum at 122 AU from the Sun is presented for galactic electrons over an energy range from 1 MeV to 50 GeV that can be considered the lowest possible local interstellar spectrum (LIS). The focus of this ...
    • Modelling the effects of scattering parameters on particle-drift in the solar modulation of galactic cosmic rays 

      Ngobeni, M.D.; Potgieter, M.S. (Elsevier, 2015)
      It is well known that particle drift motions are suppressed by diffusive scattering as established by direct numerical simulations. The effect of constant scattering on the drift velocities of charged particles has always ...
    • Modulation of galactic protons in the heliosphere during the unusual solar minimum of 2006 to 2009 

      Potgieter, M.S.; Vos, E.E.; Boezio, M.; De Simone, N.; Di Felice, V. (Springer Verlag, 2014)
      The last solar minimum activity period, and the consequent minimum modulation conditions for cosmic rays, was unusual. The highest levels of galactic protons were recorded at Earth in late 2009 in contrast to expectations. ...
    • Solar modulation of cosmic rays 

      Potgieter, Marius S. (Springer Nature, 2013)
      This is an overview of the solar modulation of cosmic rays in the heliosphere. It is a broad topic with numerous intriguing aspects so that a research framework has to be chosen to concentrate on. The review focuses on ...
    • A study of the global heliospheric modulation of galactic carbon 

      Ngobeni, M.D.; Potgieter, M.S. (Elsevier, 2014)
      Observations of galactic Carbon in the heliosphere provide a useful tool with which a comprehensive description of the global modulation of cosmic rays both inside and outside off the solar wind termination shock (TS) can ...
    • Where does the heliospheric modulation of galactic cosmic rays start? 

      Strauss, R.D.; Potgieter, M.S. (Elsevier, 2014)
      The long outstanding question of where the heliospheric (solar) modulation of galactic cosmic rays actually begins, in terms of spatial position, as well as at what high kinetic energy, can now be answered. Both answers ...