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Femtosecond laser based x-ray sources and their applications in phase contrast imaging

The focus of this dissertation is to study the keV X-ray emission from different Z material to develop compact, quasi-continuous tabletop K sources for the application of in-line phase contrast imaging, X-ray diffraction experiments and X-ray microscopy. The emission occurs from plasma produced by focusing 120 fs, 800 nm and 300 J Ti:Sapphire laser pulses up to an intensity of few times 1016 W/cm2 on Cu, Fe and Ag metal targets. The main interest of these experiments is to characterize the fast electrons and X-ray emission from the laser plasma interaction. The investigation of X-ray emission energy and spectral characteristics is carried out by employing three detector systems which include filtered pin-diode, Charge Coupled Device and CdTe pulse height detectors. Scaling of photon flux as a function of incident laser energy is measured and related to the dynamics and absorption mechanisms involved in laser matter interaction.
Specifically the construction and evaluation of K X-ray sources operated at 1 kHz repetition rate is reported with a photon flux of ~ 7109 photon/s, 3109 photon/s and 1.4107 photon/s around the K line for Cu, Fe and Ag respectively. These K fluences correspond to energy conversion efficiencies of around Cu = 310-5, Fe = 1.0610-5 and Ag = 210-7. The Cu and Fe K X-ray sources are applied to thin biological specimens and low atomic number (Z) materials to record in-line phase contrast images. It is demonstrated that the laser based K
sources can serve as alternative sources for conventional X-ray radiography of biological samples in clinical applications. / Photonics and Plasmas

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1047
Date06 1900
CreatorsAli, Atif
ContributorsRobert Fedosejevs (Electrical and Computer Engineering), Ying Tsui (Electrical and Computer Engineering), Wojciech Rozmus (Physics)
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Format2098077 bytes, application/pdf
RelationChakera, J. A. (2008). http://apl.aip.org/applab/v93/i26/p261501_s1, Chakera, J.A. (2008). http://absimage.aps.org/image/MWS_DPP08-2008-001289.pdf, Ali, Atif (2009). http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05227388

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