Sökning: "electrons"

Visar resultat 1 - 5 av 750 avhandlingar innehållade ordet electrons.

  1. 1. Energy and intensity modulated radiation therapy with electrons

    Författare :Lennart Olofsson; Mikael Karlsson; Magnus Karlsson; Björn Zackrisson; Erik Traneus; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation sciences; Radiation therapy; Conformal therapy; IMRT; Electrons; Electron treatment head; Electron MLC; Bremsstrahlung reduction; Integral dose; Penumbra; Output factor; Strålningsvetenskap; Radiation biology; Strålningsbiologi; radiofysik; radiation physics;

    Sammanfattning : In recent years intensity modulated radiation therapy with photons (xIMRT) has gained attention due to its ability to reduce the dose in the tissues close to the tumour volume. However, this technique also results in a large low dose volume. LÄS MER

  3. 2. Interacting electrons and persistent currents

    Författare :Peter Sandström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; interacting electrons; persistent currents; Wigner crystal; Aharonov-Bohm effect; Luttinger liquid; one dimension;

    Sammanfattning : .... LÄS MER

  4. 3. Experiments on Laser-Based Particle Acceleration : Beams of Energetic Electrons and Protons

    Författare :Kristoffer Svensson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; acceleration; electrons; protons; Fysicumarkivet A:2016:Svensson;

    Sammanfattning : This thesis describes experiments involving laser-plasma-based acceleration of electrons and protons, using the techniques of laser wakefield acceleration (LWFA) and target normal sheath acceleration (TNSA). By using extremely high accelerating field strengths, up to the order of TV m-1, it is possible to reach high kinetic particle energies over very short distances. LÄS MER

  5. 4. Synchrotron radiation from runaway electrons in plasmas

    Författare :Adam Stahl; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; runaway electrons; critical electric field; fusion plasma physics; tokamak; synchrotron radiation;

    Sammanfattning : Highly relativistic runaway electrons are of great concern in the area of fusion energy research, since their presence in tokamak plasmas have the potential to hinder the successful and stable operation of the device, and potentially cause severe structural damage. In this thesis, runaway electron generation dynamics is investigated using the newly developed efficient computational tool CODE. LÄS MER

  7. 5. Momentum-space dynamics of runaway electrons in plasmas

    Författare :Adam Stahl; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; synchrotron radiation; tokamak; critical electric field; non-linear collision operator; slide-away; runaway electrons; fusion-plasma physics;

    Sammanfattning : Fast electrons in a plasma experience a friction force that decreases with increasing particle speed, and may therefore be continuously accelerated by sufficiently strong electric fields. These so-called runaway electrons may quickly reach relativistic speeds. LÄS MER