scholarly journals Data for Beryllium–Hydrogen Charge Exchange in One and Two Centres Models, Relevant for Tokamak Plasmas

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
Petr A. Sdvizhenskii ◽  
Inga Yu. Tolstikhina ◽  
Valery S. Lisitsa ◽  
Alexander B. Kukushkin ◽  
Sergei N. Tugarinov
Keyword(s):  
Charge Exchange ◽  
Hydrogen Charge ◽  
Edge Plasma ◽  
High Resolution Spectroscopy ◽  
Visible Range ◽  
Observation Data ◽  
Atomic Mass Unit ◽  
Mass Unit ◽  
Quantum Numbers ◽  
Impurity Ions

Data on the cross section and kinetic rate of charge exchange (CX) between the bare beryllium nucleus, the ion Be(+4) and the neutral hydrogen atom are of great interest for visible-range high-resolution spectroscopy in the ITER tokamak because beryllium is intended as the material for the first wall in the main chamber. Here an analysis of available data is presented, and the data needs are formulated. Besides the active probe signal produced by the CX of the diagnostic hydrogen neutral beam with impurity ions in plasma, a passive signal produced by the CX of impurity ions with cold edge plasma is also important, as it shows in observation data from the JET (Joint European Torus) tokamak with an ITER-like beryllium wall. Data in the range of a few eV/amu to ~100 eV/amu (amu stands for the atomic mass unit) needed for simulations of level populations for principal and orbital quantum numbers in the emitting beryllium ions Be(+3) can be obtained with the help of two-dimensional kinetic codes. The lack of literature data, especially for data resolved in orbital quantum numbers, has instigated us to make numerical calculations with the ARSENY code. A comparison of the results obtained for the one-centre Coulomb problem using an analytic approach and for the two-centre problem using numerical simulations is presented.

scholarly journals Volatile loss following cooling and accretion of the Moon revealed by chromium isotopes

2018 ◽  
Vol 115 (43) ◽  
pp. 10920-10925 ◽  
Author(s):  
Paolo A. Sossi ◽  
Frédéric Moynier ◽  
Kirsten van Zuilen
Keyword(s):  
Atomic Mass Unit ◽  
The Moon ◽  
Volatile Elements ◽  
Mass Unit ◽  
Earth’S Mantle ◽  
Refractory Elements ◽  
Common Precursor ◽  
Lunar Rocks ◽  
Evaporative Loss ◽  
Volatile Loss

Terrestrial and lunar rocks share chemical and isotopic similarities in refractory elements, suggestive of a common precursor. By contrast, the marked depletion of volatile elements in lunar rocks together with their enrichment in heavy isotopes compared with Earth’s mantle suggests that the Moon underwent evaporative loss of volatiles. However, whether equilibrium prevailed during evaporation and, if so, at what conditions (temperature, pressure, and oxygen fugacity) remain unconstrained. Chromium may shed light on this question, as it has several thermodynamically stable, oxidized gas species that can distinguish between kinetic and equilibrium regimes. Here, we present high-precision Cr isotope measurements in terrestrial and lunar rocks that reveal an enrichment in the lighter isotopes of Cr in the Moon compared with Earth’s mantle by 100 ± 40 ppm per atomic mass unit. This observation is consistent with Cr partitioning into an oxygen-rich vapor phase in equilibrium with the proto-Moon, thereby stabilizing the CrO2 species that is isotopically heavy compared with CrO in a lunar melt. Temperatures of 1,600–1,800 K and oxygen fugacities near the fayalite–magnetite–quartz buffer are required to explain the elemental and isotopic difference of Cr between Earth’s mantle and the Moon. These temperatures are far lower than modeled in the aftermath of a giant impact, implying that volatile loss did not occur contemporaneously with impact but following cooling and accretion of the Moon.

Negative-Kaon-Hydrogen Charge-Exchange Scattering at 1.8 GeV/c

1972 ◽  
Vol 5 (11) ◽  
pp. 2711-2720 ◽  
Author(s):  
Norman D. Sossong ◽  
Robert Ellsworth ◽  
James R. Carlson ◽  
Howard F. Davis ◽  
Delbert E. Jauch
Keyword(s):  
Charge Exchange ◽  
Hydrogen Charge ◽  
Exchange Scattering

scholarly journals High Resolution Spectroscopy With Molecular Beams and Tunable Lasers

1998 ◽  
Vol 18 (1-2) ◽  
pp. 1-11 ◽  
Author(s):  
R. Vetter ◽  
P. Luc ◽  
C. Amiot
Keyword(s):  
Electronic Structure ◽  
High Resolution ◽  
Diatomic Molecules ◽  
Reaction Dynamics ◽  
Molecular Beams ◽  
Tunable Lasers ◽  
High Resolution Spectroscopy ◽  
Absorption Bands ◽  
Quantum Numbers ◽  
Laser Techniques

High resolution Doppler-free laser techniques are used in beam experiments to improve the spectroscopic description of complex diatomic molecules. The case of TiO is considered here for its implication in reaction dynamics studies and its interest in Astrophysics. Two absorption bands in the visible have been analyzed: B3Π−X3 Δ(1−0) and c1Φ−a1 Δ(0−0). Owing to accurate wavenumber measurements, it has been possible to extend the analysis to high rotational quantum numbers and to carry out detailed spectroscopic calculations. They show that a careful revisiting of the TiO electronic structure is necessary.

Photoionization and Photofragmentation of BxNy Clusters Produced by Photoablation of Boron Nitride Followed by Supersonic Expansion Cooling

1992 ◽  
Vol 285 ◽  
Author(s):  
Paul A. Roland ◽  
Sam J. La Placa ◽  
James J. Wynne
Keyword(s):  
Mass Spectrum ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Atomic Mass ◽  
Atomic Mass Unit ◽  
Experimental Conditions ◽  
Supersonic Expansion ◽  
Mass Unit ◽  
Expansion Cooling ◽  
532 Nm

ABSTRACTPhotoablation of isotopically pure boron metal and hexagonal boron nitride with a 532 nm laser, followed by supersonic expansion cooling, produces a variety of Bx, and BxNy, clusters, which are detected by photoionization of the neutral clusters with a 194 nm laser, followed by time-of-flight (TOF) mass spectrometry. Under certain experimental conditions, the mass spectrum derived from boron nitride shows resolved peaks corresponding to the clusters Bx+1Ny+. Under different experimental conditions, the mass spectrum shows an unresolved region corresponding to clusters ranging from atomic mass unit 100–1000 as well as resolved peaks, corresponding to Bx+ clusters for x = 2 − 100. These resolved peaks grow with increasing photoionization fluence, while the envelope of the unresolved region changes shape and grows with a diminished dependence on fluence. These data are interpreted as evidence that the unresolved clusters are being photofragmented as well as photoionizated by the 194 nm radiation, and the products of such photofragmentation are the aforementioned Bx+ clusters.

Excited states of positronium in positron–hydrogen charge exchange

1978 ◽  
Vol 56 (5) ◽  
pp. 565-570 ◽  
Author(s):  
V. S. Kulhar ◽  
C. S. Shastry
Keyword(s):  
Excited States ◽  
Charge Exchange ◽  
Cross Sections ◽  
Ground State ◽  
Born Approximation ◽  
Energy Region ◽  
Hydrogen Charge ◽  
Positronium Formation ◽  
State Approximation ◽  
Higher Excited States

The two state approximation method for the study of the rearrangement collisions is applied to the process of positronium formation in excited states for positron–hydrogen charge exchange collisions. Differential and integrated cross sections are computed for positronium formation in 2S, 2P, and 3S excited states. The results obtained in the energy region 2 to 10 Ry are compared with positronium formation cross sections in ground state. Total positronium formation cross sections including the contributions of capture into all the higher excited states of positronium are also computed in the first Born approximation and the two state approximation in the energy region considered.

New Drilling Muds for Drilling in Clay Rocks

2017 ◽  
Author(s):  
Sławomir Wysocki ◽  
Rafał Wiśniowski ◽  
Magdalena Gaczoł
Keyword(s):  
Side Chains ◽  
Atomic Mass Unit ◽  
Cationic Polymers ◽  
Technological Parameters ◽  
Mass Unit ◽  
Water Based ◽  
Amine Groups ◽  
Clay Rocks ◽  
Drilling Muds ◽  
Selection Of

The paper describes studies on the development of the new formulas of water-based drilling mud for drilling in clays and shales. The research were undertaken as a part of the OPTIDRILTEC project. First stage of the project included studies related to selection of ionic inhibitors of hydration. The tests of inorganic agents with various concentrations influence on technological parameters of the developed drilling muds was undertaken. The disintegration and linear swelling tests under influence of developed muds with different ionic inhibitors were conducted on the rock samples. Miocene shale was used as the model rocks. Within a framework of the project, it was conducted selection of the polymeric inhibitors of hydration. Subsequently, different polymers were tested for the influence on technological parameters of drilling muds as well as on disintegration and linear swelling of model rocks. Studies also consists of synthesis of short-chained cationic polymers (with primary amine groups in the side chains) and cationic-anionic polymers (with, apart amine groups, sulfonic amine groups). Synthesized polymers are characterized by low molecular masses (about 10.000 – 20.000 atomic mass unit) and small steric hindrance of side chains. The studies allowed development of new water-based mud formulas for drilling in clay rocks. Developed drilling muds are characterized by good technological parameters, resistance to temperature and to salts along with effective preservation against disintegration and swelling of clay rocks. Moreover, based on the research results it can be observed that synthesized cationic polymers are efficient inhibitors of clay rocks hydration. Newly developed drilling muds could be successfully applied in the oil and gas industry causing improved drilling conditions and decreased drilling costs.

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