Browsing by Author "Escalona, M."

Now showing 1 - 8 of 8
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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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    Comparative study on the dynamics and the composition between a pulsed laser deposition (PLD) and a plasma enhanced PLD (PE-PLD)
    (2021) Escalona, M.; Bhuyan, H.; Valenzuela, J.C.; Ibacache, S.; Wyndham, E.; Favre, M.; Veloso Espinosa, Felipe; Ruiz, H.M.; Wagenaars, E.
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    Effect of RF acetylene plasma on the composition and dynamics of a titanium plasma plume in a plasma enhanced pulsed laser deposition system
    (2025) Bhuyan, H.; Escalona, M.; Villegas, R.; Mal, E.; Cisternas, M.; Saikia, P.; Bora, B.; Kausik, S. S.; Wyndham, E.; Favre, M.
    We report the effect of radio frequency (RF) acetylene plasma on the dynamics and composition of titanium (Ti) plasma plume in a plasma-enhanced pulsed laser deposition (PEPLD) system. The titanium target, mounted inside a capacitively coupled RF discharge, was ablated by using a nanosecond Nd:YAG pulsed laser at 1064 nm with a power density of 2.65 GW/cm(2). The experiments were performed at different operating pressures of acetylene. Fast imaging and optical emission spectroscopy were employed to study the physics behind the pulsed laser deposition in both (PLD) and PEPLD systems. A nonlinear dependence of the plasma plume evolution was observed over a range of pressure. Different expansion regimes correspond to the pressure of the experiments. The plume expansion velocity ranges between 6 x 10(3) m/s and 30 x 10(3) m/s. Emission spectra reveal the presence of C II and Ti II lines depending on the experimental conditions. The presence of background RF plasma leads to substantial enhancement of the emission intensity of the C II spectral lines. In addition, with increasing RF power and background pressure, the intensities of the C II spectral lines increase; whereas the intensities of the Ti II spectral lines decrease with the increase in RF power. Plasma temperature was estimated from the Ti II lines using the Boltzmann plot method, whereas the electron density was estimated from the Stark-broadened Ti II line at 454.9 nm. The calculated densities and temperatures lie between 10(17)-10(18 )cm(-3) and 0.8-2.0 eV, respectively. These results show the effects of the different backgrounds (either neutral or RF plasma) on the propagation of the laser-produced plasma (LPP), which we propose to be useful in the thin film deposition process using PLD.
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    Feeding and bone turnover in gastric bypass
    (2014) Valderas Igor, Juan Patricio; Padilla Pérez, Oslando; Solari Gajardo, Sandra; Escalona, M.; González Vicente, Gilberto
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    La hipótesis de Pedersen no es suficiente : otros nutrientes además de la glucosa explicarían la macrosomía fetal en pacientes diabéticas gestacionales con sobrepeso y buen control glicémico
    (2013) Olmos Coelho, Pablo Roberto; Martelo, G.; Reimer, V.; Rigotti Rivera, Attilio; Busso, Dolores; Belmar Jones, Cristián Gastón; González Pérez, Rogelio Iván; Goldenberg, D.; Samith Catalán, Bárbara Patricia; Santos Martín, José Luis; Escalona, M.; Quezada, T.; Faundez, J.; Nicklitschek, I.
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    Perfil lipídico en mujeres embarazadas sanas de tres regiones de Chile
    (2014) Olmos Coelho, Pablo Roberto; Escalona, M.; Illanes, S.; Caradeux, J.; Mardones, G.; Olivari, D.; Fuentes, L.; Acosta, A.; Rigotti Rivera, Attilio; Busso, Dolores; Santos Martín, José Luis; Poblete, J.; Vera, C.; Belmar Canales, Jorge; Goldenberg, D.; Samith, B.; Niklitschek, I.; Mertens, N.
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    Preventive Letter : Doubling the Return Rate After Gestational Diabetes Mellitus
    (2015) Olmos Coelho, Pablo Roberto; Borzone, Gisella; Berkowitz Fiebich, Loni; Mertens, N.; Busso, Dolores; Santos Martín, José Luis; Poblete L., José A.; Vera Pérez-Gacitúa, Claudio Mauricio; Belmar Jones, Cristián Gastón; Goldenberg, D.; Samith, B.; Acosta, A.; Escalona, M.
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    Wrinkled titanium nitride nanocomposite for robust bendable electrodes
    (2019) Gence, Loik; Escalona, M.; Castillo, C.; Quero, F.; Saikia, P.; Wheatley, Robert Alastair; Diaz-Droguett, D.E.; Retamal Ponce, María José; Volkmann, Ulrich; Bhuyan, Heman