Experimental analysis of the particle transport in the magnetized plasma column with an application to the helicon discharge

International audienceDifferent transport mechanisms in a magnetized radio frequency plasmadischarge in the IShTAR device are compared. The total cross fieldparticle transport systematically shows the best agreement with theturbulent diffusion. Also, the ion mobility dominated transport couldsubstantially contribute to radial losses. The relative role of paralleland perpendicular losses in the overall particle confinement is alsocompared. The total perpendicular particle losses are comparable or evenlarger than the parallel ones, imposing a practical limitation onachieving high density plasma simply combining several helicon antennaesequentially arranged along the glass tube. For the same reason,reducing the diameter of a source tube, in an attempt to achieve ahigher plasma density, could be not very efficient when perpendicularparticle loss is dominant

Modification of the zirconia ceramics by different calcium phosphate coatings:comparative study

The aim of this study was to characterize different calcium phosphate coatings and evaluate in vitro cell response of these materials to ceramics implants. The physical and chemical properties of calcium phosphate coatings formed by RF-magnetron sputtering of calcium phosphate tribasic, hydroxyapatite, calcium phosphate monobasic, calcium phosphate dibasic dihydrate and calcium pyrophosphate powders were characterized. Cell adhesion and cell viability were examined on calcium phosphate coatings using mesenchymal stem cells. The results of cytotoxicity measurements of the calcium phosphate coatings revealed that only the coating obtained by RF-magnetron sputtering of the calcium phosphate dibasic dihydrate and calcium phosphate tribasic powders possessed lower cell viability than the zirconia substrate. The coating formed by sputtering of the calcium phosphate tribasic powder demonstrated more cells adhered onto its surface compared with other calcium phosphate coatings

Comparison study on the properties of the CaP coatings formed by RF-magnetron sputtering of the Mg- and Sr-substituted ß-tricalcium phosphate and hydroxyapatite

This article describes the influence of Mg and Sr substitutions in the structure of -tricalcium phosphate and hydroxyapatite powder targets on the deposition rate of coatings formed via RF-magnetron sputtering and their properties. It was revealed that even low doses of ionic substitutions in -tricalcium phosphate significantly affect deposition rate, morphology and physico-chemical properties of respective coatings. Similar doses of these substitutions in hydroxyapatite are not enough to influence the deposition rate, but they affect coating properties

Influence of magnesium and strontium substitutions in the structure of hydroxyapatite lattice on the deposition rate and properties of the CaP coatings formed via RF-sputtering of the powder targets

This work is dedicated to studying of the properties of the calcium phosphate (CaP) coatings deposited on Ti substrates by radio-frequency magnetron sputtering (RFMS) of three hydroxyapatite-based powder targets: pure hydroxyapatite (HA), Mg-substituted HA (Mg-HA, Mg = 0.93 ± 0.13 at.%) and Sr-substituted HA (Sr-HA, Sr ∼ 0.47 at.%). The influence of ionic substitutions in the structure of the sputtered targets on the surface morphology, physicochemical properties of the coatings and their wettability were studied. It is revealed that Mg and Sr ionic substitutions in the crystal lattice of HA at these concentrations don't affect deposition rate, however, it influences morphology, wettability and elemental and phase composition of deposited coatings

Development of a spectroscopic diagnostic tool for electric field measurements in IShTAR (Ion cyclotron Sheath Test ARrangement)

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Composite biphase coatings formed by hybrid technology for biomedical applications

Calcium-phosphate (CaP) coatings were formed via combining methods of microarc oxidation (MAO) and radiofrequency magnetron sputtering (RFMS). SEM, XPS, XRD and nanoindentation methods were used to study physico-chemical and mechanical properties of the coatings. It was revealed that the upper CaP layer changes the morphology of the coatings at the microscale and increases the Ca/P ratio of biphasic coatings