Search for dissertations about: "dynamo"

Showing result 6 - 10 of 25 swedish dissertations containing the word dynamo.

  2. 6. Flux emergence: flares and coronal mass ejections driven by dynamo action underneath the solar surface

    Author : Jörn Warnecke; Axel Brandenburg; Dikpati Mausumi; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi; teoretisk astrofysik; Theoretical Astrophysics; Space and Plasma Physics; rymd- och plasmafysik;

    Abstract : Helically shaped magnetic field structuresknown as coronal mass ejections (CMEs) are closely related to so-called eruptive flares. On the one hand, these events are broadly believed to be due tothe buoyant rise of magnetic flux tubes from the bottom of the convection zone to the photosphere where they form structures such as sunspots. READ MORE

  4. 7. The Sun, Space Weather and Effects

    Author : Magnus Wik; Fysiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; solar magnetism - solar indices - space weather - solar wind - solar dynamo - geomagnetic activity - wavelet analysis - neural networks - geomagnetically induced currents;

    Abstract : The Sun and the solar magnetic activity is responsible for a variety of effects in space and on the Earth. High energy radiation and charged particles are constantly being emitted from the solar atmosphere interacting with our atmosphere and technological systems in space and on the ground. READ MORE

  5. 8. Origin of solar surface activity and sunspots

    Author : SARAH JABBARI; AXEL BRANDENBURG; Vasilis Archontis; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun-Solar activity-Sunspots; teoretisk astrofysik; Theoretical Astrophysics;

    Abstract : In the last few years, there has been significant progress in the development of a new model for explaining magnetic flux concentrations, by invoking the negative effective magnetic pressure instability (NEMPI) in a highly stratified turbulent plasma. According to this model, the suppression of the turbulent pressure by a large-scale magnetic field leads to a negative contribution of turbulence to the effective magnetic pressure (the sum of non-turbulent and turbulent contributions). READ MORE

  6. 9. Numerical studies of current profile control in the reversed-field pinch

    Author : Jon-Erik Dahlin; Jan Scheffel; Roberto Paccagnella; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Reversed-Field Pinch; RFP; Current Profile Control; CPC; DEBS; DEBSP; active control; feedback; MHD.; Fusion; Fusion;

    Abstract : The Reversed-Field Pinch (RFP) is one of the major alternatives for realizing energy production from thermonuclear fusion. Compared to alternative configurations (such as the tokamak and the stellarator) it has some advantages that suggest that an RFP reactor may be more economic. READ MORE

  7. 10. Experimental studies of confinement in the EXTRAP T2 and T2R reversed field pinches

    Author : Marco Cecconello; KTH; []
    Keywords : extap t2; extrap t2r; reversed field pinch; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : The confinement properties of fusion plasmas are affected bymagnetic and electrostatic fluctuations. The determination ofthe plasma confinement properties requires the measurement ofseveral global and local quantities such as the ion andelectron temperatures, the electron and neutral densityprofiles, the radiation emissivity profiles, the ohmic inputpower and the particle and heat diffusivities. READ MORE