Sökning: "electron beam profile"
Visar resultat 16 - 20 av 28 avhandlingar innehållade orden electron beam profile.
16. Experiments on Laser-Based Particle Acceleration : Beams of Energetic Electrons and Protons
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
17. Polymer Light Emitting Devices : A study on how the electrode-polymer interface affects the performance of polymer light emitting devices
Sammanfattning : The research reported in this thesis is concerned with a new type of semiconductor device that can be realised by using thin films of semiconducting polymers, or conjugated polymers. In this thesis only one family of these conjugated polymers is studied, namely poly-(para-phenylene vinylene) and derivatives thereof. LÄS MER
18. Nanofabrication of Diffractive Soft X-ray Optics
Sammanfattning : This thesis summarizes the present status of the nanofabrication of diffractive optics, i.e. zone plates, and test objects for soft x-ray microscopy at KTH. The emphasis is on new and improved fabrication processes for nickel and germanium zone plates. LÄS MER
19. Investigation of deep levels in bulk GaN
Sammanfattning : The first gallium nitride (GaN) crystal was grown by hydride vapor phase epitaxy in 1969 by Maruska and Tietjen and since then, there has been an intensive development of the field, especially after the ground breaking discoveries concerning growth and p-type doping of GaN done by the 2014 year Nobel Laureates in Physics, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura. GaN and its alloys with In and Al belong to a semiconductor group which is referred as the III-nitrides. LÄS MER
20. Controlled Trapping in Laser Wakefield Accelerators
Sammanfattning : Experimental studies of laser-driven acceleration of charged particles, in particular electrons and protons, are described in this dissertation. Tightly focused femtosecond laser pulses with intensities exceeding 1018 W/cm2 were used to accelerate charged particles to high energies over distances of a few millimeters. LÄS MER
