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Abstract The collisional radiative models used in the modeling of beam emission spectroscopy diagnostics neglect atom–atom collisions because of a lack of sufficiently detailed atomic data. Filling this scantiness we performed a classical trajectory Monte Carlo simulations to calculate the cross sections for various channels in collisions between H + H2 and Li + H2 for a wide range of projectile energies. Based on the calculated cross sections, a simplified version of the collisional radiative model has been derived. We show that the model is suitable to obtain the beam attenuation in neutral gases outside of the confined plasma region. A strong density dependence has been found for each beam species. Graphical abstract

The transport of energetic electrons is sensitive to magnetic perturbations. By using three-dimensional numerical simulation of test particle drift orbits we show that the transport of untrapped electrons through an open region with magnetic perturbations cannot be described by a diffusive process. Based on our test particle simulations, we propose a model that leads to an exponential loss of particles.

Synchrotron radiation images from runaway electrons (REs) in an ASDEX Upgrade discharge disrupted by argon injection are analysed using the synchrotron diagnostic tool Soft and coupled fluid-kinetic simulations. We show that the evolution of the runaway distribution is well described by an initial hot-tail seed population, which is accelerated to energies between 25–50 MeV during the current quench, together with an avalanche runaway tail which has an exponentially decreasing energy spectrum. We find that, although the avalanche component carries the vast majority of the current, it is the high-energy seed remnant that dominates synchrotron emission. With insights from the fluid-kinetic simulations, an analytic model for the evolution of the runaway seed component is developed and used to reconstruct the radial density profile of the RE beam. The analysis shows that the observed change of the synchrotron pattern from circular to crescent shape is caused by a rapid redistribution of the radial profile of the runaway density.

A recently published scheme for inertial fusion based on instantaneous heating of an uncompressed fuel is criticized. It is shown that efficient fusion and “time-like” fusion burn propagation cannot be realized due to the low nuclear reaction cross-sections. The suggested use of nanospheres inside the volume of the target to support the fast heating of the fuel is also questioned.

Identification and monitoring of gaseous species released during thermal decomposition of pure thiourea, (NH2)2C=S in argon, helium and air atmosphere have been carried out by both online coupled TG-FTIR and simultaneous TG/DTA-MS apparatuses manufactured by TA Instruments (USA). In both inert atmospheres and air between 182 and 240°C the main gaseous products of thiourea are ammonia (NH3) and carbon disulfide (CS2), whilst in flowing air sulphur dioxide (SO2) and carbonyl sulphide (COS) as gas phase oxidation products of CS2, and in addition hydrogen cyanide (HCN) also occur, which are detected by both FTIR spectroscopic and mass spectrometric EGA methods. Some evolution of isothiocyanic acid (HNCS) and cyanamide (NH2CN) vapours have also observed mainly by EGA-FTIR, and largely depending on the experimental conditions. HNCS is hardly identified by mass spectrometry. Any evolution of H2S has not been detected at any stage of thiourea degradation by either of the two methods. The exothermic heat effect of gas phase oxidation process of CS2 partially compensates the endothermicity of the corresponding degradation step producing CS2.

The injection of energetic neutral particles into the plasma of magnetic confinement fusion reactors is a widely-accepted method for heating such plasmas; various types of neutral beam are also used for diagnostic purposes. Accurate atomic data are required to properly model beam penetration into the plasma and to interpret photoemission spectra from both the beam particles themselves (e.g. beam emission spectroscopy) and from plasma impurities with which they interact (e.g. charge exchange recombination spectroscopy). This paper reviews and compares theoretical methods for calculating ionization, excitation and charge exchange cross sections applied to several important processes relevant to neutral hydrogen beams, including H + Be 4+ and H + H + . In particular, a new cross section for the proton-impact ionization of H (1s) is recommended which is significantly larger than that previously accepted at fusion-relevant energies. Coefficients for an empirical fit function to this cross section and to that of the first excited states of H are provided and uncertainties estimated. The propagation of uncertainties in this cross section in modeling codes under JET-like conditions has been studied and the newly-recommended values determined to have a significant effect on the predicted beam attenuation. In addition to accurate calculations of collisional atomic data, the use of these data in codes modeling beam penetration and photoemission for fusion-relevant plasma density and temperature profiles is discussed. In particular, the discrepancies in the modeling of impurities are reported. The present paper originates from a Coordinated Research Project (CRP) on the topic of fundamental atomic data for neutral beam modeling that the International Atomic Energy Agency (IAEA) ran from 2017 to 2022; this project brought together ten research groups in the fields of fusion plasma modeling and collisional cross section calculations. Data calculated during the CRP is summarized in an appendix and is available online in the IAEA’s atomic database, CollisionDB.

Three complexes of general formula PtCl2R2 were synthesized, where R is the amine ligand with aromatic substituents. Coordination compounds [Pt(an)2Cl2] (1), [Pt(pa)2Cl2] (2) and [Pt(aph)2Cl2] (3), where an = 2-aminonaphthalene, pa = 2-aminopyrimidine, aph = 4-anilinophenol, were characterized by on-line coupled TG/DTA-MS, powder XRD and spectroscopic techniques (FTIR, ESI–MS and NMR), and tested against selected Gram(+) and Gram(–) bacteria. The thermal data show that all three compounds contain lattice or absorbed water, and the stability of the anhydrous compounds in nitrogen decreases in the order 2 > 1 > 3. Above 200 °C, the complexes loose characteristic fragments of their ligands. The spectroscopic data are in accordance with the thermal properties of the samples and prove their composition. The compounds are more effective inhibitors of Gram(+) than Gram(−) bacteria.

The velocity-space anisotropy of suprathermal electron distributions is a source of free energy that may destabilize plasma waves through a resonant interaction between the waves and the energetic electrons. In this work we use a suprathermal electron distribution appropriate for the case when the accelerating electric field is near-critical and we investigate the frequencies, wave numbers and propagation angles of the most unstable waves using a general dispersion relation. It is shown that if the electric field is sub-critical, the anisotropy is not enough to drive electromagnetic waves unstable, as the Landau damping of the waves overwhelms the drive through the anomalous Doppler resonance. In the case when the electric field is supercritical, two types of electromagnetic waves will be destabilized, the electron-whistler and the extraordinary electron wave. The number of electrons for destabilization of the latter is several orders of magnitude lower than for the electron-whistler wave. Consequently, the threshold for destabilization of the extraordinary electron wave is much lower.

This paper discusses the changes in the structure and thermal reduction of nanosize hexagonal ammonium tungsten bronze (HATB), (NH4)0.33−xWO3−y, which were caused by K+ ion exchange (doping) and studied by XRD, XPS, 1H-MAS NMR, FTIR, SEM and TG/DTA-MS. Comparison of the cell parameters of undoped and doped HATB revealed that both a and c cell parameters decreased after the ion exchange reaction, which showed that smaller K+ ions partly replaced the larger NH4+ ions in the hexagonal channels of HATB. After the reaction, from the hexagonal channels less NH3 evolved, which also supported the incorporation of K+ ions into the hexagonal channels.

In this research thermal analysis and kinetics of ten lignite's and two oil shale samples of different origin were performed using a TA 2960 thermal analysis system with thermogravimetry (TG/DTG) and differential al analysis (DTA) modules. Experiments were performed with a sample size of ~10 mg, heating rate of 10°C min-1. Flow rate was kept constant (10 L h-1) in the temperature range of 20-900°C. Mainly three different reaction regions were observed in most of the samples studied. The first region was due to the evaporation of moisture in the sample. The second region was due to the release of volatile matter and burning of carbon and called as primary reaction region. Third region was due to the decomposition of mineral matter in samples studied. In kinetic calculations, oxidation of lignite and oil shale is described by first-order kinetics. Depending on the characteristics of the samples, the activation energy values are varied and the results are discussed.