Now showing items 1-10 of 15

    • An ab initio approach to the heliospheric modulation of galactic cosmic rays 

      Minnie, Jaco (North-West University, 2006)
      In the present study we aim to further our understanding of charged particle transport in a magnetized medium. To this end, we perform direct numerical simulations of particle transport in a turbulent magnetic field. From ...
    • An ab initio approach to the historical modulation of cosmic rays 

      Wolmarans, Carel Pieter (North-West University (South Africa), 2021)
      The relationship between observed cosmic-ray intensities and the heliospheric magnetic field during the early space age is generally considered to be anomalous, relative to their relationship observed at later times. ...
    • Cosmic ray modulation processes in the heliosphere 

      Vos, Etienne Eben (North-West University, 2011)
      The solar minimum of 2009 has been identified as an exceptional event with regard to cosmic ray (CR)modulation, since conditions in the heliosphere have reached unprecedented quiet levels. This unique minimum has been ...
    • Cosmic rays in the dynamic heliosheath 

      Ferreira, S.E.S.; Potgieter, M.S.; Scherer, K. (Elsevier, 2008)
      Cosmic ray modulation in the outer heliosphere is discussed from a modeling perspective. Emphasis is on the transport and acceleration of these particles at and beyond the solar wind termination shock in the inner heliosheath ...
    • The effect of a Fisk-Parker hybrid magnetic field on cosmic rays in the heliosphere 

      Krüger, Tjaart Petrus Jakobus (North-West University, 2005)
      The existence of a Fisk-type heliospheric magnetic field (HMF) is one of the most debated questions in cosmic-ray modulation. Recently, Burger and Hitge [2004] developed a divergence-free Fisk-Parker hybrid magnetic field ...
    • The effect of the heliospheric current sheet on cosmic-ray modulation 

      Moloto, Katlego Daniel (North-West University (South Africa), Potchefstroom Campus, 2015)
      The heliospheric current sheet is a dominant feature of the heliosphere. As solar activity increases, the tilt angle of the current sheet increases, and so does the region swept out by this structure, to cover most of ...
    • Effects of termination shock acceleration on cosmic rays in the heliosphere 

      Langner, Ulrich Wilhelm (North-West University, 2004)
      The interest in the role of the solar wind termination shock (TS) and heliosheath in cosmic ray (CR) modulation studies has increased sigm6cantly as the Voyager 1 and 2 spacecraft approach the estimated position of the TS. ...
    • Long-term variation in cosmic-ray modulation 

      Mosotho, Moshe Godfrey (North-West University (South Africa), 2017)
      The transport of cosmic rays inside the heliosphere can be described b the Parker equation (Parker, 1965). Since there are no full analytica solutions to the Parker equation, two first-order approximate solutions o the ...
    • Modelling charge-sign dependent modulation of cosmic rays in the heliosphere 

      Vos, Etienne Eben (North-West University (South Africa), 2016)
      The solar minimum of cycle 23/24 has seen exceptionally quiet levels of solar activity and heliospheric modulation, which resulted in the highest cosmic ray (CR) spectrum ever recorded at Earth in December 2009 by the ...
    • Modelling of galactic carbon in an asymmetrical heliosphere: effects of asymmetrical modulation conditions 

      Ngobeni, M.D.; Potgieter, M.S. (Elsevier, 2012)
      Observations of galactic cosmic rays (GCRs) from the two Voyager spacecraft inside the heliosheath indicate significant differences between them, suggesting that in addition to a possible global asymmetry in the north–south ...