Accession Number : ADA265442


Title :   Radiative Preheat in Strongly Coupled, Laser Accelerated Plasmas


Descriptive Note : Final rept.,


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Giuliani, John L , Jr ; Mulbrandon, Margaret ; Davis, Jack


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a265442.pdf


Report Date : 14 May 1993


Pagination or Media Count : 13


Abstract : A 1-D radiation hydrodynamics code is employed to model the interaction of the NIKE KrF laser with a planar CH target. Three cases are compared to demonstrate the effects of radiative preheat: (1) the hydrodynamics of the laser target interaction with a high density equation-of-state (EOS) but without radiation; (2) the inclusion of radiation production and transport using collisional radiative equilibrium for the ionization dynamics; and (3) the addition of an approximate model for the pressure ionization and continuum lowering in the ionization dynamics. These last aspects are shown to significantly affect the results due to the strongly coupled plasma state of the compressed, accelerated target. As one moves from case (1) to (3) the density gradient near the ablation front is substantially reduced, implying a decrease in the Rayleigh-Taylor instability growth rates, but at the consequence of a hot and broad accelerating target. Furthermore, the photon spectra emerging from the rearside of the target is shifted in case (3) as compared to (2) toward higher energies and away from the absorption peak of neutral DT fuel.


Descriptors :   *RADIATION , *PLASMAS(PHYSICS) , *LASER TARGETS , ABLATION , INTERACTIONS , SURFACES , DEPOSITION , ELECTRONS , HYDROCARBONS , PHOTONS , LASER INDUCED FUSION , RAYLEIGH TAYLOR INSTABILITY , COUPLINGS , EQUATIONS OF STATE , COLLISIONS , HYDRODYNAMICS , PLASTICS , HEAT , DOPING , IONIZATION , SPECTRA , TRANSPORT PROPERTIES , HIGH ENERGY , ACCELERATION , DYNAMICS , DENSITY


Subject Categories : Radiation and Nuclear Chemistry
      Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy
      Plasma Physics and Magnetohydrodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE