Laser-Matter Interactions at Extreme Irradiance: X-ray Generation and Relativistic Channelling
type: CreativeWork
description: This thesis summarizes experimental work in which the powerful Ti:sapphire lasers at the High Power Laser Facility at the Lund Laser Centre have been employed to investigate laser-produced X-rays and relativistic channelling. These lasers produce short pulses, of the order of 50 fs, with energies ranging from 1 mJ to 1 J. Thus, the peak powers reach several terawatts and with the most powerful laser system the peak irradiance exceeds 10^19 W/cm^2. Furthermore, X-rays generated at a synchrotron radiation facility have been used in conjunction with a short-pulse laser to study temporal oscillations on a picosecond timescale in a crystalline material. In the continuation of a research project, pursued at the High Power Laser Facility since 1992, X-ray generation up to several hundred keV has been investigated by focusing the laser pulses onto solid metal targets. One of the motivations for these experiments is the potential use of laser-produced X-rays in medical radiography. In another experiment the temporal features of X-rays of a few keV was investigated. In this case, the X-rays were generated by focusing laser pulses into clustered argon gas jets. Various detection techniques have been used to measure the X-ray spectrum in the different experiments, including energy-resolved photon counting with a charge-coupled device (CCD) and X-ray diffraction on crystals in combination with a CCD. Germanium detectors have also been employed in order to investigate the X-ray spectrum above a few keV more accurately. The laser-produced X-rays show extraordinary properties compared for example with those generated by the common X-ray tube. Very short pulse duration and a small source size are two important factors that differentiate the laser-based X-ray source from others. In particular, when focusing onto solid targets, a compact, high-repetition-rate laser system has been employed to evaluate the use of laser-produced X-rays (above 10~keV) in diagnostic medicine by recording …
abstract: This thesis summarizes experimental work in which the powerful Ti:sapphire lasers at the High Power Laser Facility at the Lund Laser Centre have been employed to investigate laser-produced X-rays and relativistic channelling. These lasers produce short pulses, of the order of 50 fs, with energies ranging from 1 mJ to 1 J. Thus, the peak powers reach several terawatts and with the most powerful laser system the peak irradiance exceeds 10^19 W/cm^2. Furthermore, X-rays generated at a synchrotron radiation facility have been used in conjunction with a short-pulse laser to study temporal oscillations on a picosecond timescale in a crystalline material. In the continuation of a research project, pursued at the High Power Laser Facility since 1992, X-ray generation up to several hundred keV has been investigated by focusing the laser pulses onto solid metal targets. One of the motivations for these experiments is the potential use of laser-produced X-rays in medical radiography. In another experiment the temporal features of X-rays of a few keV was investigated. In this case, the X-rays were generated by focusing laser pulses into clustered argon gas jets. Various detection techniques have been used to measure the X-ray spectrum in the different experiments, including energy-resolved photon counting with a charge-coupled device (CCD) and X-ray diffraction on crystals in combination with a CCD. Germanium detectors have also been employed in order to investigate the X-ray spectrum above a few keV more accurately. The laser-produced X-rays show extraordinary properties compared for example with those generated by the common X-ray tube. Very short pulse duration and a small source size are two important factors that differentiate the laser-based X-ray source from others. In particular, when focusing onto solid targets, a compact, high-repetition-rate laser system has been employed to evaluate the use of laser-produced X-rays (above 10~keV) in diagnostic medicine by recording …
author: Sjögren, Anders
language: eng
keywords: Atom and Molecular Physics and Optics, relativistic self-focusing, particle acceleration, x-ray generation, radiography, Laserteknik, Laser technology, laser-produced plasma, light scattering, Fysicumarkivet A:2002:Sjögren
date published: 2002
date modified: 2026-07-24T03:00:02Z
provider: University of Lund
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Atomic Physics, Department of Physics, Lund University