62 research outputs found
Preliminary studies of creation of gold nanoparticles on titanium surface towards biomedical applications
Enhanced physicochemical and biological properties of ion-implanted Titanium using Electron Cyclotron Resonance ion sources
The surface properties of metallic implants play an important role in their
clinical success. Improving upon the inherent shortcomings of Ti implants, such
as poor bioactivity, is imperative for achieving clinical use. In this study,
we have developed a Ti implant modified with Ca or dual Ca + Si ions on the
surface using an electron cyclotron resonance ion source (ECRIS). The
physicochemical and biological properties of ion-implanted Ti surfaces were
analyzed using various analytical techniques, such as surface analyses,
potentiodynamic polarization and cell culture. Experimental results indicated
that a rough morphology was observed on the Ti substrate surface modified by
ECRIS plasma ions. The in vitro electrochemical measurement results also
indicated that the Ca + Si ion-implanted surface had a more beneficial and
desired behavior than the pristine Ti substrate. Compared to the pristine Ti
substrate, all ion-implanted samples had a lower hemolysis ratio. MG63 cells
cultured on the high Ca and dual Ca + Si ion-implanted surfaces revealed
significantly greater cell viability in comparison to the pristine Ti
substrate. In conclusion, surface modification by electron cyclotron resonance
Ca and Si ion sources could be an effective method for Ti implants
Plazmafizikai kutatások ECR ionforrással = Plasma physics research by ECR ion source
Az ATOMKI eredetileg nagytöltĂ©sű nehĂ©zionok előállĂtására kĂ©szĂĽlt elektron-ciklotronrezonanciás (ECR) ionforrásában fullerĂ©n (C60) plazmákat állĂtottunk elĹ‘. Magát az ionforrást is jelentĹ‘sen átalakĂtottuk, Ăgy a világon eddig publikált legmagasabb intenzitásĂş fullerĂ©nion nyalábokat kaptuk: (C60+)-bĂłl 500 nA, (C60++)-bĂłl 1500 nA. C60+Fe Ă©s C60+N keverĂ©kplazmákat tanulmányoztunk, a kivont ionnyalábban a normál fullerĂ©nnĂ©l nagyobb tömegű rĂ©szecskĂ©ket detektáltunk. Nyalábspektrum-analĂzisek, ESR Ă©s TEM vizsgálatok kimutatták, hogy e rĂ©szecskĂ©k között olyan molekulák is vannak, melyben N, ill. Fe kapcsolĂłdik kĂĽlönbözĹ‘kĂ©ppen C58, C59 Ă©s C60 szĂ©ngömbökhöz. Az ECR-plazma tehát alkalmas fullerĂ©nek Ă©s más anyagok szintĂ©zisĂ©re. Ar, Xe Ă©s Fe plazmákrĂłl röntgenfelvĂ©tel sorozatokat kĂ©szĂtettĂĽnk, a plazma ionjainak tĂ©r- Ă©s energiaeloszlását vizsgáltuk. Hagyományos Ă©s emissziĂłs Langmuir-szondákkal a plazma helytĹ‘l fĂĽggĹ‘ paramĂ©tereit (sűrűsĂ©g, potenciál) vizsgáltuk. KifejlesztettĂĽnk egy programcsomagot (TrapCAD), mellyel igen nagyszámĂş (pl. 10^5) elektron mozgása Ă©s energiaváltozása tanulmányozhatĂł Ă©s követhetĹ‘ grafikusan is az ECR Ă©s hasonlĂł ionforrásokban. Az ECR ionforrást jelentĹ‘sen átalakĂtottuk, mostantĂłl kĂ©t kĂĽlönbözĹ‘ ĂĽzemmĂłdban használhatĂł. AlapkiĂ©pĂtĂ©sben a berendezĂ©s továbbra is kismĂ©retű, magas ionizáltsági fokĂş nehĂ©zionplazmákat állĂt elĹ‘, melybĹ‘l nagytöltĂ©sű ionnyalábok vonhatĂłk ki. Az Ăşj elrendezĂ©sben nagymĂ©retű, de kevĂ©sbĂ© lefosztott plazmákat kapunk. Ekkor a berendezĂ©s elsĹ‘sorban anyagkutatásra, plazma-felĂĽlet kölcsönhatások tanulmányozására alkalmas. A világon ez az elsĹ‘ ilyen kĂ©tfunkciĂłs ECR-berendezĂ©s. | C60 plasmas were produced in the ATOMKI electron cyclotron resonance (ECR) ion source which was originally constructed for the production of highly charged heavy ions. After significant modifications the ever published highest intensities of fullerene ion beams were recorded: 500 nA of (C60)+ and 1500 nA of (C60)++. C60+Fe and C60+N mixture plasmas were studied, in the extracted beam spectra heavier particles than the normal fullerenes, were detected. Beam spectra analysis, ESR and TEM investigations showed that among these particles there were molecules in which N, or Fe were connected by different ways to C58, C59 and C60 carbon balls. This proved that the ECR plasma is suitable to synthesize fullerenes with other materials. X-ray photos were made of Ar, Xe and Fe plasmas and the spatial and energy distribution of the plasma ions were studied. Some local plasma parameters (density, potential) were investigated by traditional and emission-type Langmuir-probes. We developed a code (TrapCAD) to simulate and follow graphically the movement and energy evolution of large number (e.g. 10^5) of electrons in ECR and similar ion sources. The ECR ion source was significantly transformed and from now it can be used in two different working modes. In basic configuration the facility delivers the usual small size, highly charged heavy ion plasmas from which highly charged ion beams can be extracted. In the new arrangement large size, but less ionized plasmas are obtained. This mode is convenient for material research and for plasma-surface investigations. This is the first ECR facility in the world with such two functions
Conductivity mechanism probed by ion transmission through nanocapillaries during the discharging process
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Ionok ütközése atomokkal, molekulákkal és felületekkel: magasabbrendű folyamatok = Collisions of ions with atoms molecules and surfaces: Higher-order processes
Ionok Ă©s atomok illetve molekulák ĂĽtközĂ©seiben megmutattuk, hogy kis (1-100 keV/nukleon) ionenergiákon a többszörös elektronszĂłrási folyamat (az un. Fermi-shuttle mechanizmus) járulĂ©ka elĂ©rheti a teljes elektron-emissziĂł 5-10 százalĂ©kát, Ă©s a nagyenergiás elektronok ki-bocsátásában ez a folyamat meghatározĂł lehet. A hidrogĂ©nmolekula ionizáciĂłjában magasabb rendben fellĂ©pĹ‘ interferenciajelensĂ©gek közĂĽl pontosan megmĂ©rtĂĽk a másodrendű folyamat járulĂ©kának szögeloszlását. Találtunk egy magasabb frekvenciájĂş komponenst is, melynek Ă©rtelmezĂ©se egyenlĹ‘re nyitott kĂ©rdĂ©s. Ion-molekula ĂĽtközĂ©sekben megmĂ©rtĂĽk a kilĂ©pĹ‘ molekula-fragmentumok szög Ă©s energia-eloszlását, Ă©s Ă©rtelmeztĂĽk annak anizotrĂłp jellegĂ©t. Az ion-felĂĽlet kölcsönhatások terĂĽletĂ©n a szigetelĹ‘ fĂłliákban kialakĂtott nanokapillárisok un. ionterelĹ‘ hatását vizsgálatuk. FelĂ©pĂtettĂĽk az ehhez szĂĽksĂ©ges mĂ©rĹ‘berendezĂ©st, majd elsĹ‘kĂ©nt kimutattuk Ă©s megmĂ©rtĂĽk alumĂniumoxid nanokapilláris minták ionterelĹ‘ kĂ©pessĂ©gĂ©t. ElemeztĂĽk a lĂtiumszerű lövedĂ©kionokon vĂ©gbemenĹ‘ kĂ©telektronos, un. transzfer-loss folyamatot. Megmutattuk, hogy egy metastabil kvartett állapot keltĂ©si hatáskeresztmetszetĂ©t a lövedĂ©k magasabb hĂ©jaira befogĂłdĂł elektronok teljes hozama szabja meg, amivel megmagyaráztuk egy anomálisan nagynak tekintett hatáskeresztmetszet eredetĂ©t. | It has been shown in collisions of ions with atoms and molecules that at low ion energies (1-100 keV/u), the contribution of the multiple electron scattering sequences (the so called Fermi-shuttle mechanism) may amount of 5-10% of the total electron emission. Morover, this process can be dominant in the emission of high energy electrons. Studying the higher order interference effects in the ionization of the hydrogen molecule, we accurately measured the angular distribution of the second order component. A higher frequency contribution has also been found, which has no evident interpretation yet. We measured the angular and energy distribution of molecular fragments in ion-molecule collisions, and provided an interpretation for its anisotropic properties. In the field of ion-surface interaction, we studied the ion-guiding ability of the nanocapillaries formed in foils of isolating materials. We have constructed the measuring apparatus. We determined first time the ion guiding properties of capillary samples formed in anodic alumina. We analyzed the transfer-loss process (a two-electron transition) on lithium like projectile ions. We have shown that the production cross section of a metastable quartet state is deter-mined by the capture yield to all the higher n shells of the projectile. This fact explained the anomaly of a ?too large? measured cross section
Electron cyclotron resonance ion source plasma characterization by energy dispersive x-ray imaging
Pinhole and CCD based quasi-optical x-ray imaging technique was applied to investigate the plasma of an electron cyclotron resonance ion source (ECRIS). Spectrally integrated and energy resolved images were taken from an axial perspective. The comparison of integrated images taken of argon plasma highlights the structural changes affected by some ECRIS setting parameters, like strength of the axial magnetic confinement, RF frequency and microwave power. Photon counting analysis gives precise intensity distribution of the x-ray emitted by the argon plasma and by the plasma chamber walls. This advanced technique points out that the spatial positions of the electron losses are strongly determined by the kinetic energy of the electrons themselves to be lost and also shows evidences how strongly the plasma distribution is affected by slight changes in the RF frequency. © 2017 IOP Publishing Ltd
Egzotikus atomfizikai folyamatok plazmákban és szilárdtestek felületén = Exotic Atomic Processes in Plasmas and on Solid Surfaces
Kutatási eredmĂ©nyeink többsĂ©ge a debreceni elektron-ciklotronrezonanciás (ECR) plazma- Ă©s ionforrás folyamatos fejlesztĂ©sĂ©n Ă©s többcĂ©lĂş, a plazmafizikátĂłl az asztrofizikáig, a nanotechnolĂłgiátĂłl az orvostudományig terjedĹ‘ alkalmazásán alapul. A kĂsĂ©rleti elrendezĂ©sek fĂĽggvĂ©nyĂ©ben vizsgáltuk az előállĂtott nagytöltĂ©sű nehĂ©zionok, plazmák, ionnyalábok (Ne1+-8+, Ar1+-16+, Xe1+-24+, C601+-3+, ....) paramĂ©tereit (ionizáciĂłs összetĂ©tel, sűrűsĂ©g, röntgenspektrumok, potenciális Ă©s kinetikai energia) Ă©s azokat összehasonlĂtottuk más plazmafizikai kutatások adataival, elĹ‘segĂtve a kozmikus vizsgálatok eredmĂ©nyeinek a teljesebb megĂ©rtĂ©sĂ©t is. A nagytöltĂ©sű ionok Ă©s a bizonyos speciális szilárdtestek (funkcionális amorf kalkogenid alapĂş fĂ©lvezetĹ‘ rĂ©tegek, kapillárisokat tartalmazĂł polimer rĂ©tegek, titán implantátumok, stb.) kölcsönhatásainak specifikus, mikro- Ă©s nanoskálán jelentkezĹ‘ tulajdonságait Ă©s mechanizmusát kutattuk, kĂĽlönös tekintettel az ionok töltĂ©se által keltett átalakulásokra Se, AsSe rĂ©tegekben, Ti felĂĽleten, valamint mikrokapillárisok belsejĂ©ben. Ezek alapján cĂ©loztuk meg a vizsgált ionnyalábok potenciális alkalmazásait felĂĽleti fĂ©lvezetĹ‘ mikro- Ă©s nanostruktĂşrák in situ előállĂtására, biokompatibilis implantátumok felĂĽleti mĂłdosĂtására, ionnyaláb fĂłkuszálĂł, irányĂtĂł mikroeszközök kialakĂtására. EredmĂ©nyeink többsĂ©ge az ECR ionforrás alkalmazására Ă©pĂĽlĹ‘ Ăşj kutatási-fejlesztĂ©si tĂ©mákat (pl. funkcionizált biokompatibilis anyagok, integrált ionoptika) alapoz meg. | Majority of our research results base on continuous development of the Electron Cyclotron Resonance (ECR) plasma and ion source and its multipurpose application from plasma physics to astrophysics and from nanotechnology to medical sciences. The parameters (composition, density, X-ray spectra, potential and kinetic energy) of the generated highly charged heavy ions (Ne1+-8+, Ar1+-16+, Xe1+-24+, C601+-3+, ....) have been investigated in dependence from the experimental conditions and the results were compared with data of other plasma physics research which enabled understanding more deeply some cosmic phenomena. The specific characteristics and mechanisms of interaction of highly charged ions with solid surfaces (functional amorphous chalcogenide-based semiconductor layers, polymer layers with capillaries, titanium implants, etc.) at micro- and nano-scale dimensions were investigated with a special attention to ion-charge induced transformations in Se, AsSe layers and on Ti surfaces, as well as to the ion transport inside the micro-capillaries. It was the basis of our targeted research on the possibilities of applications of these ion beams for the in situ creation of surface micro- and nanostructures on given semiconductors, for surface modification of biocompatible implants, as well as for development of micro-tools for guiding and focusing ion beams. Most of our results serve a good basis for new ECR-based R&D themes like new biocompatible materials, integrated ion optics
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