Sökning: "radio frequency waves"
Visar resultat 16 - 20 av 35 avhandlingar innehållade orden radio frequency waves.
16. VLF Chorus Activity Associated with Substorm Particle Injections
Sammanfattning : The Substorm Chorus Event (SCE) is a Very Low Frequency(VLF) radio phenomenon observed on the ground after the onsetof the substorm expansion phase. It consists of a band of VLFchorus emissions with rising upper and lower cutofffrequencies. LÄS MER
17. Modeling RF waves in hot plasmas using the finite element method and wavelet decomposition : Theory and applications for ion cyclotron resonance heating in toroidal plasmas
Sammanfattning : Fusion energy has the potential to provide a sustainable solution for generating large quantities of clean energy for human societies. The tokamak fusion reactor is a toroidal device where the hot ionized fuel (plasma) is confined by magnetic fields. Several heating systems are used in order to reach fusion relevant temperatures. LÄS MER
18. Implementing spectrum commons: Implications for Thailand
Sammanfattning : Spectrum is a natural and limited resource that needs to be managed both internationally and nationally because of the unique propagation characteristics of radio waves. Once transmitted, a radio signal propagates until its power is depleted. Furthermore, electromagnetic energy does not recognize borders between countries. LÄS MER
19. Coupling and Absorption of Lower Hybrid Waves in Current Profile Control Experiments in the JET Tokamak
Sammanfattning : Current drive with radio frequency waves in the lower hybrid frequency range is an important method of current profile control via non-inductive current drive in tokamaks. This thesis is concerned with profile control experiments, carried out with the lower hybrid current drive system in the Joint European Torus (JET) tokamak, with the aim to explore scenarios for operation in high confinement regimes with peaked pressure profiles. LÄS MER
20. Optimization and Physical Bounds for Passive and Non-passive Systems
Sammanfattning : Physical bounds in electromagnetic field theory have been of interest for more than a decade. Considering electromagnetic structures from the system theory perspective, as systems satisfying linearity, time-invariance, causality and passivity, it is possible to characterize their transfer functions via Herglotz functions. LÄS MER