Sökning: "Time metrology"
Visar resultat 1 - 5 av 30 avhandlingar innehållade orden Time metrology.
1. Real-Time Time Metrology Using Space Geodetic Methods
Sammanfattning : Two main objectives in time and frequency metrology are the realization of the SI unit of time, and the construction and dissemination of atomic time scales based on the SI second. This thesis is mainly concerned with the latter of the two and has investigated the characteristics of space geodetic time and frequency comparison methods. LÄS MER
2. Current measurement by real-time counting of single charges
Sammanfattning : The first real-time observation of time correlated single-electron tunnelling is reported in this thesis. This is a direct detection of charge discreteness in an electrical current.When a current, I, flows through a chain of metallic islands, connected by small tunnel junctions, a lattice of charges is formed due to the Coulomb repulsion. LÄS MER
3. Time-resolved detection of temporally correlated, single-charge tunnelling
Sammanfattning : We report real-time detection of the single charges that constitute a small electrical current, as they flow through a nano-electronic device. This represents a direct demonstration of charge discreteness in an electrical current. LÄS MER
4. Spatial and temporal metrology of intense attosecond pulses
Sammanfattning : Attosecond pulses are short enough to capture the electronic dynamics in atoms and molecules. The work presented in this thesis deals with the generation and optimization of attosecond extreme-ultraviolet (XUV) pulses. LÄS MER
5. Studies of Tropospheric and Stratospheric Aerosol using Ion Beam Analysis
Sammanfattning : Atmospheric aerosol particles are believed to have an impact on the radiative forcing of the earth's surface. The predicted results indicate a net cooling effect on the global climate, however there are few studies available to substantiate this and experimental data are needed. LÄS MER