Search for dissertations about: "RADIATION LOSSES"

Showing result 1 - 5 of 74 swedish dissertations containing the words RADIATION LOSSES.

  2. 1. Radiation in simulations of high intensity laser-matter interaction

    Author : Erik Karl Wallstén Wallin; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; plasma; nonlinear dynamics; particle-in-cell; Manley-Rowe; radiation reaction; synchrotron radiation;

    Abstract : We consider electromagnetic waves propagating in plasmas, with two main themes covered. First nonlinear plasma theory and wave-wave interaction. Here a wave-wave symmetry, the Manley-Rowe relations, is used as a method of determining the physicality of modified plasma fluid equations. READ MORE

  4. 2. The influence of modelling parameters on the simulation of car tyre rolling losses and rolling noise

    Author : Carsten Hoever; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling resistance; modelling parameters; parameter study; radiation; tyre road noise; tyres; tyre road interaction; waveguide finite element;

    Abstract : Due to legislative changes within the EU there is an increased demand for improvement in car tyre rolling resistance and noise generation. Yet, apart from empirical data based on measurements, there is little information concerning the relationship between rolling resistance and rolling noise generation. READ MORE

  5. 3. Dosimetry and radiation quality in fast-neutron radiation therapy : A study of radiation quality and basic dosimetric properties of fast-neutrons for external beam radiotherapy and problems associated with corrections of measured charged particle cross-sections

    Author : Jonas Söderberg; Gudrun Alm Carlsson; Crister Ceberg; Linköpings universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neutron; Dosimetry; Radiotherapy; Monte Carlo; Microdosimetry; Cross-section; RBE; LET; Energy-loss corrections; Radiological physics; Radiofysik;

    Abstract : The dosimetric properties of fast-neutron beams with energies ≤80 MeV were explored using Monte Carlo techniques. Taking into account transport of all relevant types of released charged particles (electrons, protons, deuterons, tritons, 3He and α particles) pencil-beam dose distributions were derived and used to calculate absorbed dose distributions. READ MORE

  6. 4. Radiation induced losses in Ytterbium doped laser materials

    Author : Sara Rydberg; Magnus Engholm; Hans-Erik Nilsson; Mittuniversitetet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : In this work, two types of ytterbium (Yb) doped laser materials are studied, crys-talline Yb:YAG and amorphous Yb/Al silica in both preform and fiber. Yb is suitableas a laser ion because of its simple energy level structure and low quantum defect. READ MORE

  7. 5. Pushing methods for plasma simulations into the QED regime

    Author : Erik Karl Wallstén Wallin; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LWFA; nonlinear dynamics; plasma; Manley-Rowe; particle-in-cell; synchrotron radiation; radiation reaction;

    Abstract : The interaction between a super-intense laser pulse, with intensity up to 10²² W/cm², and a plasma opens new regimes of physics, with new questions and more demand on existing numerical tools. Relativistic and quantum effects which are negligible for lower laser intensities become important and must be properly modelled to generate reliable predictions. READ MORE