• myGriffith
    • Staff portal
    • Contact Us⌄
      • Future student enquiries 1800 677 728
      • Current student enquiries 1800 154 055
      • International enquiries +61 7 3735 6425
      • General enquiries 07 3735 7111
      • Online enquiries
      • Staff phonebook
    View Item 
    •   Home
    • Griffith Theses
    • Theses - Higher Degree by Research
    • View Item
    • Home
    • Griffith Theses
    • Theses - Higher Degree by Research
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

  • All of Griffith Research Online
    • Communities & Collections
    • Authors
    • By Issue Date
    • Titles
  • This Collection
    • Authors
    • By Issue Date
    • Titles
  • Statistics

  • Most Popular Items
  • Statistics by Country
  • Most Popular Authors
  • Support

  • Contact us
  • FAQs
  • Admin login

  • Login
  • Laser produced plasmas for the generation of X-rays

    Thumbnail
    View/Open
    Hemantha Rao, Kavya Final Thesis_Redacted.pdf (25.08Mb)
    Author(s)
    Hemantha Rao, Kavya
    Primary Supervisor
    Sang, Robert
    Litvinyuk, Igor
    Year published
    2019-01-12
    Metadata
    Show full item record
    Abstract
    Laser Produced Plasmas (LPP) are a better source to increase the energy cut-off of the harmonics generated due to their larger ionisation potential than the conventional neutral gas media, if optimised properly. The experiments detailed in the thesis aim towards the use of LPP as a medium for the generation of bright coherent EUV/XUV table-top sources. A detailed spatio-temporal characterisation of LPP's generated from Al and Cr targets via non-invasive optical emission spectroscopy (OES) and time-resolved plume imaging are performed to investigate plasma features and optimise them. While ns LPP's are spatio-temporally ...
    View more >
    Laser Produced Plasmas (LPP) are a better source to increase the energy cut-off of the harmonics generated due to their larger ionisation potential than the conventional neutral gas media, if optimised properly. The experiments detailed in the thesis aim towards the use of LPP as a medium for the generation of bright coherent EUV/XUV table-top sources. A detailed spatio-temporal characterisation of LPP's generated from Al and Cr targets via non-invasive optical emission spectroscopy (OES) and time-resolved plume imaging are performed to investigate plasma features and optimise them. While ns LPP's are spatio-temporally optimised for Al IV/Al III with the irradiation energy as the control parameter, the ps LPP's are optimised for Al III using the single pulse (SP) and double pulse (DP) schemes. Experiments on Cr plasmas are also performed and the changes in plume morphology upon implementing SP and DP schemes are investigated via plume imaging and the abundance of various species in the plume were investigated via time-resolved OES. The DP schemes are investigated in detail to find out the influence of parameters such as the polarisation, delay between the two pulses, energy in the first pulse and the ambient pressure on the plume morphology. Building and extending the experimental setup to conduct the proposed experiments aiming towards increasing the energy cut-off of the harmonics using LPP as the nonlinear medium comprises the second part of the thesis. A High-order Harmonic Generation (HHG) set up is built and tested using harmonics generated in Ar gas. The HHG system developed here would further be modified to take care of the plasma fluorescence as well as to accommodate higher order harmonics. These spatio-temporally optimised LPP's together with the set-up are anticipated to produce HHG sources with higher brilliance than the commercial tabletop sources, adding energy tunability to these sources. Additional experiments on the angle resolved X-ray emissions in the range of 30 keV to 150 keV from LPP from metals (Al and Cr) and their alloys (Al-Cr) are carried out and detailed here; which can also be used as a source of X-ray radiation.
    View less >
    Thesis Type
    Thesis (PhD Doctorate)
    Degree Program
    Doctor of Philosophy (PhD)
    School
    School of Environment and Sc
    DOI
    https://doi.org/10.25904/1912/271
    Copyright Statement
    The author owns the copyright in this thesis, unless stated otherwise.
    Subject
    Laser produced plasma
    X-rays
    Spatio-temporal optimisation
    Energy cut-off
    Publication URI
    http://hdl.handle.net/10072/385616
    Collection
    • Theses - Higher Degree by Research

    Footer

    Disclaimer

    • Privacy policy
    • Copyright matters
    • CRICOS Provider - 00233E

    Tagline

    • Gold Coast
    • Logan
    • Brisbane - Queensland, Australia
    First Peoples of Australia
    • Aboriginal
    • Torres Strait Islander