Ozone production in electron irradiated CO:O ices.

The detection of ozone (O) in the surface ices of Ganymede, Jupiter's largest moon, and of the Saturnian moons Rhea and Dione, has motivated several studies on the route of formation of this species. Previous studies have successfully quantified trends in the production of O as a result of the irradiation of pure molecular ices using ultraviolet photons and charged particles (, ions and electrons), such as the abundances of O formed after irradiation at different temperatures or using different charged particles. In this study, we extend such results by quantifying the abundance of O as a result of the 1 keV electron irradiation of a series of 14 stoichiometrically distinct CO:O astrophysical ice analogues at 20 K.

Ionization cross sections in collisions between two hydrogen atoms by a quasi-classical trajectory Monte Carlo model.

The hydrogen-hydrogen collision system is studied employing a four-body quasi-classical trajectory Monte Carlo model of Kirschbaum and Wilets (QCTMC-KW, C. L. Kirschbaun and L.

Comparative electron irradiations of amorphous and crystalline astrophysical ice analogues.

Laboratory studies of the radiation chemistry occurring in astrophysical ices have demonstrated the dependence of this chemistry on a number of experimental parameters. One experimental parameter which has received significantly less attention is that of the phase of the solid ice under investigation. In this present study, we have performed systematic 2 keV electron irradiations of the amorphous and crystalline phases of pure CHOH and NO astrophysical ice analogues.

Guiding of keV ions between two insulating parallel plates.

Experimental data are presented for low-energy singly charged ion transport between two insulating parallel plates. Using a beam intensity of approximately 20 pA, measurements of the incoming and transmitted beams provide quantitative temporal information about the charge deposited on the plates and the guiding probability. Using a smaller beam intensity (~ 1 pA) plate charging and discharging properties were studied as a function of time.

X-ray diagnostics of ECR ion sources-Techniques, results, and challenges.

The high magnetic confinement provided by the minimum-B structure of electron cyclotron resonance ion sources (ECRIS) hosts a non-equilibrium plasma, composed of cold multi-charged ions and hot electrons whose energy can expand up to ≈1 MeV. With a very limited accessibility, the ECR plasma is difficult to study. The x-ray photons generated by the interaction of the warm and hot electron populations within the plasma, as well as the photons generated by electrons lost to the chamber wall, are a signal of great interest as it gives an insight to the properties of the ECR plasma.

Hidden behind the mask: An authentication study on the Aztec mask of the Museum of Ethnography, Budapest, Hungary.

Turquoise covered mosaic objects - especially masks - were attractive components of treasures transported to Europe from Mexico after the fall of the Aztec Empire in the 1500s. According to our present knowledge, the mosaic masks were manufactured for ritual purpose. The main material of mosaics, the turquoise was a high-prestige semi-precious stone among Mexican native people.

Identifying the complexity of the holographic structures in strong field ionization.

We present numerical investigations of the strong-field attosecond photoelectron holography by analyzing the holographic interference structures in the two-dimensional photoelectron momentum distribution (PMD) in hydrogen atom target induced by a strong infrared laser pulse. The PMDs are calculated by solving the full-dimensional time-dependent Schrödinger equation. The effect of the number of optical cycles on the PMD is considered and analyzed.

Proton beam irradiation induces invisible modifications under the surface of painted parchment.

Ion beam analysis plays an important role in cultural heritage (CH) studies as it offers a combination of simultaneous and complementary analytical techniques (PIXE/PIGE/RBS) and spatially resolved mapping functions. Despite being considered non-destructive, the potential risk of beam-induced modifications during analysis is increasingly discussed. This work focuses on the impact of proton beams on parchment, present in our CH in form of unique historical manuscripts.

Optical properties of amorphous carbon determined by reflection electron energy loss spectroscopy spectra.

We present the combined experimental and theoretical investigations of the optical properties of amorphous carbon. The reflection electron energy loss spectra (REELS) spectra of carbon were measured using a cylindrical mirror analyzer under ultrahigh vacuum conditions at primary electron energies of 750, 1000 and 1300 eV. The energy loss function and thereby the refractive index and the extinction coefficient were determined from these REELS spectra in a wide loss energy range of 2-200 eV by applying our reverse Monte Carlo method.

The Effect of the PVA/Chitosan/Citric Acid Ratio on the Hydrophilicity of Electrospun Nanofiber Meshes.

In this study, scaffolds were prepared via an electrospinning method for application in oral cavities. The hydrophilicity of the fiber mesh is of paramount importance, as it promotes cell spreading; however, the most commonly used polyvinyl alcohol (PVA) and other hydrophilic fiber meshes immediately disintegrate in aqueous media. In contrast, the excessive hydrophobicity of the scaffolds already inhibits cells adhesion on the surface.

Direct Measurement of the ^{13}C(α,n)^{16}O Cross Section into the s-Process Gamow Peak.

One of the main neutron sources for the astrophysical s process is the reaction ^{13}C(α,n)^{16}O, taking place in thermally pulsing asymptotic giant branch stars at temperatures around 90 MK. To model the nucleosynthesis during this process the reaction cross section needs to be known in the 150-230 keV energy window (Gamow peak). At these sub-Coulomb energies, cross section direct measurements are severely affected by the low event rate, making us rely on input from indirect methods and extrapolations from higher-energy direct data.

State selective classical electron capture cross sections in Be + H(1s) collisions with mimicking quantum effect.

We present state-selective electron capture cross sections in collision between Be and ground state hydrogen atom. The n- and nl-selective electron capture cross sections are calculated by a three-body classical trajectory Monte Carlo method (CTMC) and by a classical simulation schema mimicking quantum features of the collision system. The quantum behavior is taken into account with the correction term in the Hamiltonian as was proposed by Kirschbaum and Wilets (Phys Rev A 21:834, 1980).

Evolution of anisotropic crack patterns in shrinking material layers.

Anisotropic crack patterns emerging in desiccating layers of pastes on a substrate can be exploited for controlled cracking with potential applications in microelectronic manufacturing. We investigate such possibilities of crack patterning in the framework of a discrete element model focusing on the temporal and spatial evolution of anisotropic crack patterns as a thin material layer gradually shrinks. In the model a homogeneous material is considered with an inherent structural disorder where anisotropy is captured by the directional dependence of the local cohesive strength.

The Ice Chamber for Astrophysics-Astrochemistry (ICA): A new experimental facility for ion impact studies of astrophysical ice analogs.

The Ice Chamber for Astrophysics-Astrochemistry (ICA) is a new laboratory end station located at the Institute for Nuclear Research (Atomki) in Debrecen, Hungary. The ICA has been specifically designed for the study of the physico-chemical properties of astrophysical ice analogs and their chemical evolution when subjected to ionizing radiation and thermal processing. The ICA is an ultra-high-vacuum compatible chamber containing a series of IR-transparent substrates mounted on a copper holder connected to a closed-cycle cryostat capable of being cooled down to 20 K, itself mounted on a 360° rotation stage and a z-linear manipulator.

Study of the geometry of open channels in a layer-bed-type microfluidic immobilized enzyme reactor.

This paper aims at studying open channel geometries in a layer-bed-type immobilized enzyme reactor with computer-aided simulations. The main properties of these reactors are their simple channel pattern, simple immobilization procedure, regenerability, and disposability; all these features make these devices one of the simplest yet efficient enzymatic microreactors. The high surface-to-volume ratio of the reactor was achieved using narrow (25-75 μm wide) channels.

Femtosecond Single Cycle Pulses Enhanced the Efficiency of High Order Harmonic Generation.

High-order harmonic generation is a nonlinear process that converts the gained energy during light-matter interaction into high-frequency radiation, thus resulting in the generation of coherent attosecond pulses in the XUV and soft x-ray regions. Here, we propose a control scheme for enhancing the efficiency of HHG process induced by an intense near-infrared (NIR) multi-cycle laser pulse. The scheme is based on introducing an infrared (IR) single-cycle pulse and exploiting its characteristic feature that manifests by a non-zero displacement effect to generate high-photon energy.

Inter-laboratory comparison of ED-XRF/PIXE analytical techniques in the elemental analysis of filter-deposited multi-elemental certified reference materials representative of ambient particulate matter.

The quantification of the elemental concentration of ambient particulate matter is a challenging task because the observed elemental loadings are not well above the detection limit for most analytical techniques. Although non-destructive nuclear techniques are widely used for the chemical characterization of ambient aerosol, only one multi-element standard reference filter material that mimics ambient aerosol composition has become recently available in the market. To ensure accuracy, reliability and comparability of instruments performance, multiple reference materials with different elemental mass loadings are necessary.

Electrosprayed calcium silicate nanoparticle-coated titanium implant with improved antibacterial activity and osteogenesis.

To ensure clinical success, the implant and the surrounding bone tissue must not only be integrated, but also must not be suspected of infection. In this work, an antibacterial and bioactive nanostructured calcium silicate (CaSi) layer on titanium substrate by an electrospray deposition method was prepared, followed by annealing at 700, 750 and 800 °C to improve the bonding strength of the CaSi coating. The phase composition, microstructure and bonding strength of the CaSi coatings were examined.

Individual separation of surface, bulk and Begrenzungs effect components in the surface electron energy spectra.

We present the first theoretical recipe for the clear and individual separation of surface, bulk and Begrenzungs effect components in surface electron energy spectra. The procedure ends up with the spectral contributions originated from surface and bulk-Begrenzungs excitations by using a simple method for dealing with the mixed scatterings. As an example, the model is applied to the reflection electron energy loss spectroscopy spectrum of Si.

Angular momentum generation in nuclear fission.

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning; this phenomenon has been a mystery in nuclear physics for over 40 years. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum.

Topical Issue on many particle spectroscopy of atoms, molecules, clusters and surfaces editorial: Editorial.

Many particle spectroscopy is a subject of continued interest to many experimental and theoretical groups worldwide. It is based on the coincidence spectroscopy of minimum two particles coming from the same elementary process. It is a very powerful tool for studying not just atoms and molecules but also more extended electronic systems such as clusters and surfaces.

Elastic Electron Scattering from Methane Molecule in the Energy Range from 50-300 eV.

Electron interaction with methane molecule and accurate determination of its elastic cross-section is a demanding task for both experimental and theoretical standpoints and relevant for our better understanding of the processes in Earth's and Solar outer planet atmospheres, the greenhouse effect or in plasma physics applications like vapor deposition, complex plasma-wall interactions and edge plasma regions of Tokamak. Methane can serve as a test molecule for advancing novel electron-molecule collision theories. We present a combined experimental and theoretical study of the elastic electron differential cross-section from methane molecule, as well as integral and momentum transfer cross-sections in the intermediate energy range (50-300 eV).

PT -Symmetric Potentials from the Confluent Heun Equation.

We derive exactly solvable potentials from the formal solutions of the confluent Heun equation and determine conditions under which the potentials possess PT symmetry. We point out that for the implementation of PT symmetry, the symmetrical canonical form of the Heun equation is more suitable than its non-symmetrical canonical form. The potentials identified in this construction depend on twelve parameters, of which three contribute to scaling and shifting the energy and the coordinate.

Production cross sections of Ti in the deuteron-induced reaction on Sc up to 24 MeV.

Activation cross sections of the medically interesting radionuclide Ti were investigated in the deuteron-induced reaction on Sc. Ti can be produced in a radioactive-contamination-free form in the Sc(d,2n)Ti reaction below 15 MeV deuteron energy. The stacked foil activation technique and γ-ray spectrometry were used to determine the cross sections.