85 research outputs found
Az atomi ionizáció vizsgálata = Atomic Ionization Studies
A projekt keretĂ©ben több szemĂ©lyes találkozĂł során alakĂtottunk ki a SPARC (Stored Particle Atomic Physics Research Collaboration) kollaboráciĂłhoz kapcsolĂłdĂł mĂ©rĂ©sek Ă©s elmĂ©leti számolások terveit az e-2e folyamatok inverz kinematika mellett törtĂ©nĹ‘ tanulmányozására kvázi elektronok Ă©s ionok ĂĽtközĂ©seiben tárolĂłgyűrűknĂ©l. Nemzetközi konferencia-szekciĂłkat szerveztĂĽnk a SPARC körĂĽli tervek szĂ©leskörű bemutatására. Rendszeresen rĂ©szt vettĂĽnk más SPARC találkozĂłkon is, ahol terveinket másokkal is megvitattuk. EgyĂĽttműködĂ©sĂĽnk nem bilaterális, másokkal közös tervek kialakĂtására is sor kerĂĽlt. A projekt keretĂ©ben elvĂ©gzett kĂsĂ©rleti Ă©s elmĂ©leti munkák is a leendĹ‘ SPARC egyĂĽttműködĂ©shez kapcsolĂłdnak, ezek tervei is a közös vitákban szĂĽlettek meg, rĂ©szben most vĂ©gezzĂĽk Ĺ‘ket, rĂ©szben közlĂ©s elĹ‘tt vagy alatt állnak. Terveink, megfontolásaink egy rĂ©szĂ©t publikáltuk, illetve több elĹ‘adásban, vitában ismertettĂĽk. | Within the framework of the project, we organized a series of short bilateral meetings for working out the research plans connected to the future experimental work to study quasy-electron - ion collisions in inverse kinematics at storage rings, within the framework of the Stored Particle Atomic Physics Research Collaboration (SPARC). We jointly organized con-ference sessions for discussing SPARC related physics and instrumental plans. We regularly attended other SPARC meetings, where we discussed our plans in a wider community. Our collaboration is not only bilateral, we discussed and formed common plans with third parties too. The performed research is also strongly connected to the future work within the SPARC collaboration, their plans have been formed in our common discussions. Some of them we are still working on, some are before or under publication. Part of our considerations and plans have been published and disseminated in talks and discussions
Dissociative ionization of the H2O molecule induced by medium-energy singly charged projectiles
We report on the fragmentation of the water molecule by MeV H,
He and 650 keV N ion impact. The fragment-ion energy spectra were
measured by an electrostatic spectrometer at different observation angles. The
obtained double-differential fragmentation cross sections for N is found
to be more than an order of magnitude higher, than that for H. The
relative ratios of the fragmentation channels are also different for the three
projectiles. Additional fragmentation channels were observed in the spectra for
He and for N impact, which are missing in the case of H. From
the analysis of the kinetic energy of the fragments, the maximum observed
degree of ionization was found to be , , and for
H, He and N impact, respectively. Absolute multiple
ionization cross sections have been determined. They are compared with the
predictions of the classical trajectory Monte Carlo and
continuum-distorted-wave eikonal-initial-state theories. At lower degrees of
ionization, theories provide reasonable agreement with experiment. The
systematic overestimation of the cross section by the theories towards higher
degrees of ionization indicates the failure of the independent particle model
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
Experimental study of coherence and correlation in the anisotropy of Ne KL-LLL satellite Auger decay
Ionization of small molecules induced by H+, He+, and N+ projectiles: comparison of experiment with quantum and classical calculations
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Conductivity mechanism probed by ion transmission through nanocapillaries during the discharging process
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