Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632675
Title: A study of stimulated Brillouin scattering in laser produced plasmas
Author: Wilson, Kathryn Ann
Awarding Body: University of Strathclyde
Current Institution: University of Strathclyde
Date of Award: 2013
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Abstract:
The production of high power, short duration laser pulses is of interest to a wide variety of applications ranging from high-energy-density physics to laser-driven nuclear fusion. The exploitation of laser-plasma instabilities, in particular stimulated Brillouin scattering (SBS), for the creation of such pulses is found to have great potential. Analysis from numerical, analytical and experimental studies are presented within this thesis which were constructed to develop a platform of knowledge to enable the understanding and development of stimulated Brillouin scattering as a possible means of laser amplification to ultra-high intensities. From these studies a number of scaling laws were developed governing the optimal parameter space for the laser pump beam, probe beam and the plasma amplifier in addition to the ability to control the final amplified pulse characteristics. Optimum regions of parameter space occurring at a density of 0.3nc with pump and seed laser intensities of 1x10¹⁶16Wcm⁻² and 1x10¹⁵Wcm⁻², respectively, were found to produce efficient laser amplification of 57%. The scalability to wider regions of parameter space was also confirmed for laser intensities down to 1x10¹³3Wcm⁻². The presence of Brillouin scattering was noted for all underdense plasmas studied with Brillouin amplification being effective for densities greater than the quarter critical density level due to mode competition with Raman scattering. Collisional processes were also investigated and it was found that the introduction of collisions results in an increase in the efficiency of laser amplification via stimulated Brillouin scattering by 10% and a significant increase in the contrast of the resultant seed laser beam. Corroboration between the numerical, analytical and experimental studies undertaken indicates a high level of reliability in the results presented throughout this thesis.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.632675  DOI: Not available
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