Search for dissertations about: "electron beams"

Showing result 1 - 5 of 90 swedish dissertations containing the words electron beams.

  2. 1. Clinical application of intensity and energy modulated radiotherapy with photon and electron beams

    Author : Xiangkui Mu; Björn Zackrisson; Mikael Karlsson; Thomas Björk-Eriksson; Erik Blomquist; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Oncology; Radiotherapy; IMXT; IMET; IMPT; proton beams; electron beams; treatment planning; cancer induction; side-effects; fraction time; intensity modulated radiotherapy; Onkologi; Oncology; Onkologi; Oncology; onkologi;

    Abstract : In modern, advanced radiotherapy (e.g. intensity modulated photon radiotherapy, IMXT) the delivery time for each fraction becomes prolonged to 10-20 minutes compared with the conventional, commonly 2-5 minutes. The biological effect of this prolongation is not fully known. READ MORE

  4. 2. Studies on high brightness electron beams for short pulses and free electron laser

    Author : Sara Thorin; Lunds universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; bunch compression; sub-ps pulses; X-rays; High brightness electron beam; free electron laser; electron accelerator; collective effects.;

    Abstract : Accelerator based lightsources are one of the most powerful tools today for producing high intensity radiation at very short wavelengths. While synchrotron storage rings provide a high average brilliance in a wide wavelength range, the next generation of lightsources aim towards producing ultra-short pulses in the X-ray regime. READ MORE

  5. 3. Theoretical and Computational Studies on the Physics of Applied Magnetism : Magnetocrystalline Anisotropy of Transition Metal Magnets and Magnetic Effects in Elastic Electron Scattering

    Author : Alexander Edström; Jan Rusz; Olle Eriksson; Patrick Bruno; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magnetism; Magnetic anisotropy; DFT; Permanent magnets; Electron vortex beams; Electron microscopy; Electron scattering; Multislice methods; Magnetism; magnetisk anisotropi; permanentmagneter; täthetsfunktionalteori; elektronmikroskopi; elektronvirvelstrålar; elektronspridningsteori; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : In this thesis, two selected topics in magnetism are studied using theoretical modelling and computational methods. The first of these is the magnetocrystalline anisotropy energy (MAE) of transition metal based magnets. In particular, ways of finding 3d transition metal based materials with large MAE are considered. READ MORE

  6. 4. Electron energization in near-Earth space : Studies of kinetic scales using multi-spacecraft data

    Author : Elin Eriksson; Andris Vaivads; Masahiro Hoshino; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetic reconnection; electron acceleration; electron heating; magnetosheath; magnetotail; magnetic nulls; Cluster; Magnetospheric MultiScale; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Abstract : Plasma, a gas of charged particles exhibiting collective behavior, is everywhere in the Universe. The heating of plasma to millions of degrees and acceleration of charged particles to very high energies has been observed in many astrophysical environments. How and where the heating and acceleration occur is in many cases unclear. READ MORE

  7. 5. Electron Heating and Acceleration at Earth’s Collisionless Bow Shock

    Author : Martin Lindberg; Andris Vaivads; Philippe Savoini; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Electron; heating; Acceleration; MMS; Shock; space; plasma; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Cosmic rays are ultra-relativistic particles traveling near the speed of light permeating the galaxy. Collisionless shock waves with their ubiquity throughout the universe and excellent capability of accelerating charged particles offer an explanation to the origin of cosmic rays. READ MORE