Sökning: "tokamak"

Visar resultat 21 - 25 av 98 avhandlingar innehållade ordet tokamak.

1. 21. Simulation of runaway electron generation during plasma shutdown by impurity injection

   Författare :Tamás Fehér; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; disruption mitigation; fusion plasma physics; impurity injection; runaway electron; tokamak;

   Sammanfattning : Disruptions are dangerous instabilities in tokamaks that should be avoided or mitigated. One possible disruption mitigation method is to inject impurities into the plasma to shut it down in a controlled way. Runaway Electrons (REs) can be generated after the plasma is cooled down bythe impurities and these electrons can damage the tokamak. LÄS MER

3. 22. Resonant magnetic perturbation effect on the tearing mode dynamics : Novel measurements and modeling of magnetic fluctuation induced momentum transport in the reversed-field pinch

   Författare :Richard Fridström; Per Brunsell; Lorenzo Frassinetti; Tommaso Bolzonella; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; RFP; reversed-field pinch; tokamak; tearing mode; RMP; fusion; plasma; resonant magnetic perturbation; stochastic; magnetic; field; viscosity; mode; locking; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The tearing mode (TM) is a resistive instability that can arise in magnetically confined plasmas. The TM can be driven unstable by the gradient of the plasma current. When the mode grows it destroys the magnetic field symmetry and reconnects the magnetic field in the form of a so-called magnetic island. LÄS MER

4. 23. Effect of Partial Screening on Runaway-Electron Dynamics

   Författare :Linnea Hesslow; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fokker-Planck equation; runaway electrons; tokamak; fusion; plasma physics;

   Sammanfattning : One of the essential results of kinetic plasma physics is the runaway phenomenon: sufficiently large electric fields can accelerate a fraction of an electron population to relativistic energies. While such runaway electrons are fundamentally interesting objects of study in astrophysical settings, they are also of great practical relevance to fusion research. LÄS MER

5. 24. Simulation and analysis of radiation from runaway electrons

   Författare :Mathias Hoppe; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; tokamak; runaway electrons; synthetic diagnostics; fusion; synchrotron radiation; plasma physics; bremsstrahlung;

   Sammanfattning : Electron runaway constitutes one of the primary threats to future tokamak fusion reactors such as ITER. Successful prevention and mitigation of runaways relies on the development of theoretical models which accurately describe the dynamics of runaway electrons, and these models must in turn be validated in experiments. LÄS MER

7. 25. Modelling and Measurements of MAST Neutron Emission

   Författare :Iwona Klimek; Marco Cecconello; Jozef Ongena; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fusion; plasma diagnostics; neutron emissivity and rate; Neutron Camera; tokamak; MAST; Fysik med inriktning mot tillämpad kärnfysik; Physics with specialization in Applied Nuclear Physics;

   Sammanfattning : Measurements of neutron emission from a fusion plasma can provide a wealth of information on the underlying temporal, spatial and energy distributions of reacting ions and how they are affected by a wide range of magneto-hydro-dynamic (MHD) instabilities.This thesis focuses on the interpretation of the experimental measurements recorded by neutron flux monitors with and without spectroscopic capabilities installed on the Mega Ampere Spherical Tokamak (MAST). LÄS MER