Sökning: "electron beam"

Visar resultat 21 - 25 av 451 avhandlingar innehållade orden electron beam.

1. 21. Fabrication and Applications of a Focused Ion Beam Based Nanocontact Platform for Electrical Characterization of Molecules and Particles

   Författare :Tobias Blom; Klaus Leifer; Maria Strömme; Michel Calame; Uppsala universitet; []
   Nyckelord :Focused Ion Beam; FIB; Scanning Electron Microscopy; SEM; Nanogap electrodes; Nanostructuring; Nanofabrication; Electron Beam Lithography; Electrical characterization; Dielectrophoresis;

   Sammanfattning : The development of new materials with novel properties plays an important role in improving our lives and welfare. Research in Nanotechnology can provide e.g. cheaper and smarter materials in applications such as energy storage and sensors. LÄS MER

3. 22. Beam Diagnostics and Dynamics in Nonlinear Fields

   Författare :Jim Ögren; Roger Ruber; Volker Ziemann; Klaus Leifer; Stephen Peggs; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beam diagnostics; Nonlinear beam dynamics; Accelerator physics;

   Sammanfattning : Particle accelerators are indispensable tools for probing matter at the smallest scales and the improvements of such tools depend on the progress and understanding of accelerator physics. The Compact Linear Collider (CLIC) is a proposed, linear electron–­positron collider on the TeV-scale, based at CERN. LÄS MER

4. 23. Low Secondary Electron Yield Carbon Coatings for Electron Cloud Mitigation in Modern Particle Accelerators

   Författare :Christina Yin Vallgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Raman spectroscopy; NRA; amorphous carbon; secondary electron yield; LIU; X-Ray Photoelectron Spectroscopy; SEY; AFM; electron cloud; SPS dipole magnet;

   Sammanfattning : In order to upgrade the Large Hadron Collider (LHC) performance to be oriented towards higher energies and higher intensities in the future, a series of improvementsof the existing LHC injectors is planned to take place over the next few years. Electron cloud effects are expected to be enhanced and play a central role in limiting theperformance of the machines of the CERN complex. LÄS MER

5. 24. Structural study of zeolites utilizing novel electron crystallographic methods : A voyage into the world of zeolite structures

   Författare :Tom Willhammar; Xiaodong Zou; Raul Lobo; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron crystallography; zeolites; structure determination; disorder; electron microscopy; Structural Chemistry; strukturkemi;

   Sammanfattning : Electron crystallography has evolved as a powerful method for structural characterization of a wide range of materials. It has two significant advantages over other methods for structure determination, e.g. X-ray diffraction. LÄS MER

7. 25. Absorbed Dose Determination and Characteristics of Degraded Electron Beams: Application to Intraoperative Radiation Therapy

   Författare :Peter Björk; Internmedicin - epidemiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering; absorbed dose distribution; output factor; stopping-power ratio; beam characteristics; Monte Carlo calculation; electron beam dosimetry; applicator system; radiation therapy; linear accelerator; intraoperative radiotherapy;

   Sammanfattning : The aim of this work was to quantify limitations of and uncertainties in commonly used dosimetric techniques for relative absorbed dose determination in degraded electron beams, such as those encountered in intraoperative radiation therapy (IORT) and small-electron-field radiotherapy. Three different detector types were investigated with regard to measurements of output factors and relative absorbed dose distributions: (1) a parallel-plate ionization chamber, (2) a p-type silicon diode detector and (3) a diamond detector. LÄS MER