Sökning: "impurity transport"

Visar resultat 21 - 25 av 43 avhandlingar innehållade orden impurity transport.

  1. 21. Electron transport studies in epitaxial graphene on SiC

    Författare :Michael Winters; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Furthermore, the dispersion in graphene k is light-like for graphene monolayers implying that electron transport would behave relativistically. If vsat = vf could be achieved in the material, then it is theoretically possible to achieve THz performance in long channel devices. Despite the nice theoretical picture, Nature is hardly so forthcoming. LÄS MER

  3. 22. Thermonuclear Instabilities and Plasma Edge Transport in Tokamaks

    Författare :Tünde Fülöp; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : High-energy ions generated by fusion reactions in a burning fusion plasma may give rise to different types of wave instabilities. The present thesis investigates two types of such instabilities which recently have been observed in fusion experiments: the Toroidal Alfvén Eigenmode (TAE) instability and the magnetoacoustic cyclotron instability (MCI) which is predicted to give rise to ion cyclotron emission (ICE). LÄS MER

  4. 23. Electron Transport and Optical Properties in Mesoscopic Systems

    Författare :Anna Grincwajg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The main subject of this Thesis is optical properties of quantum point contact systems and their influence on the electron transport. A quantum point contact is a narrow constriction in a two-dimensional electron gas, where the width of the constriction can be controlled by means of a gate voltage. LÄS MER

  5. 24. Diamond Devices Based on Valley Polarization

    Författare :Nattakarn Suntornwipat; Jan Isberg; Markus Gabrysch; Saman Majdi; Hitoshi Umezawa; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CVD diamond; valleytronics; Negative Differential Mobility; NDM; electron polarization; Time-of-Flight; magnetotransport; carrier transport; drift velocity; valley-transistor; Transferred-Electron Oscillator; TEO; TED; Gunn diode;

    Sammanfattning : Diamond is a wide bandgap semiconductor with extreme properties such as high thermal conductivity, high breakdown field, high carrier mobilities and chemical inertness. These properties together with the possibility to synthesize high purity Single-Crystalline (SC) diamond by Chemical Vapor Deposition (CVD), make it a very interesting material and a candidate for use in power electronics and in hazardous environments. LÄS MER

  7. 25. Plasma-Facing Components in Tokamaks : Studies of Wall Conditioning Processes and Plasma Impact on Diagnostic Mirrors

    Författare :Álvaro García Carrasco; Marek Rubel; Marco Cecconello; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasa-wall interactions; wall conditioning; tracers; diagnostic mirrors; ICWC; Physics; Fysik;

    Sammanfattning : Understanding of material migration and its impact on the formation of co-deposited mixed material layers on plasma-facing components is essential for the development of fusion reactors. This thesis focuses on this topic. It is based on experiments performed at JET and TEXTOR tokamaks. LÄS MER