Browsing by Author "Avaria, G."

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    Bayesian inference of plasma parameters from collective Thomson scattering technique on a gas-puff near stagnation
    (2023) Escalona, M.; Valenzuela, J. C.; Avaria, G.; Veloso, F.; Wyndham, E. S.
    The Collective Thomson scattering technique has been implemented to study the stagnation of a single liner gas-puff. The plasma parameters are determined by theoretically modelling the scattering form factor in combination with Bayesian inference to provide the set of the most probable parameters that describe the experimental data. Analysis of the data reveal that incoming flows are able to interpenetrate partially. Estimation of the mean free path shows a gradual transition from a weakly collisional to a collisional regime as the plasma gets to the axis. Furthermore, we find that the ion energy at r = 2.5 mm is 13.6(-0.9)(+1.0) keV and is mostly kinetic in nature and represents 98(+10) (-9) % of the total energy. This kinetic energy is far greater than the value on axis of 3.7(-0.5)(+0.4) keV which is 84(-14)(+15) % of the total energy. Energy transfer to the electrons and radiation losses are found to be negligible by this time. A possible explanation for this energy imbalance is the presence of an azimuthal magnetic field larger than similar to 4.7 T that deflect the ions vertically. The uncertainties quoted represent 68% credible intervals.
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    Formation of hexagonal silicon carbide by high energy ion beam irradiation on Si(100) substrate
    (2007) Bhuyan, H.; Favre, M.; Valderrama, E.; Avaria, G.; Chuaqui, H.; Mitchell, I.; Wyndham, E.; Saavedra, R.; Paulraj, M.
    We report the investigation of high energy ion beam irradiation on Si (100) substrates at room temperature using a low energy plasma focus (PF) device operating in methane gas. The unexposed and ion exposed substrates were characterized by x-ray diffraction, scanning electron microscopy (SEM), photothermal beam deflection, energy-dispersive x-ray analysis and atomic force microscopy (AFM) and the results are reported. The interaction of the pulsed PF ion beams, with characteristic energy in the 60-450 keV range, with the Si surface, results in the formation of a surface layer of hexagonal silicon carbide. The SEM and AFM analyses indicate clear step bunching on the silicon carbide surface with an average step height of 50 nm and a terrace width of 800 nm.
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    Properties of Plasma Jets Emitted in Pulsed Capillary Discharges
    (2006) Avaria Saavedra, Gonzalo Felipe; Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund; Avaria, G.; Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund
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    Properties of Plasma Jets Emitted in Pulsed Capillary Discharges at Low Pressures
    (2006) Avaria Saavedra, Gonzalo Felipe; Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund; Avaria, G.; Bhuyan, Heman; Chuaqui, Hernán; Wyndham, Edmund