Search for dissertations about: "photon neutron fields"

Found 3 swedish dissertations containing the words photon neutron fields.

  2. 1. Microphysical Conditioning of Gamma-Ray Burst Shocks

    Author : Jacob Trier Frederiksen; Claes Fransson; Åke Nordlund; Mikhail V. Medvedev; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetic fields; particle acceleration; plasma instabilities; gamma-ray bursts; collisionless shocks; relativistic outflows; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; astronomi;

    Abstract : Gamma-Ray Bursts (GRBs) are believed to be connected with either collapse of massive stars or – in some cases – coalescing neutron stars, both of which cause extreme relativistic explosions observable from the entire Universe. GRBs produce rapid flashes of high energy radiation, extending up to 2MeV in photon energies: as much energy per photon as the rest mass of 4 electrons. READ MORE

  4. 2. The microdosimetric variance-covariance method used for beam quality characterization in radiation protection and radiation therapy

    Author : Jan Erik Lillhök; Lennart Lindborg; Bernd Grosswendt; Stockholms universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ionizing radiation; radiation quality; radiation protection; radiation therapy; microdosimetry; nanodosimetry; variance-covariance method; Radiological physics; Radiofysik; medicinsk strålningsfysik; Medical Radiation Physics;

    Abstract : Radiation quality is described by the RBE (relative biological effectiveness) that varies with the ionizing ability of the radiation. Microdosimetric quantities describe distributions of energy imparted to small volumes and can be related to RBE. READ MORE

  5. 3. QED and collective effects in vacuum and plasmas

    Author : Joakim Lundin; Mattias Marklund; Thomas Heinzl; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; QED; quantum electrodynamics; quantum plasmas; quantum vacuum; Plasma physics; Plasmafysik; fysik; Physics;

    Abstract : The theory of quantum electrodynamics (QED) was born out of an attempt to merge Einsteins theory of special relativity and quantum mechanics. Einsteins energy/mass equivalence together with Heisenberg's uncertainty principle allows for particle pairs to be spontaneously created and annihilated in vacuum. READ MORE