Radiolysis of Methane in a Wide‐Range Radiolysis Source of a Mass Spectrometer. I. Individual and Total Cross Sections for the Production of Positive Ions, Negative Ions, and Free Radicals by Electrons

1967 ◽  
Vol 47 (5) ◽  
pp. 1771-1774 ◽  
Author(s):  
Charles E. Melton ◽  
P. S. Rudolph
Keyword(s):  
Free Radicals ◽  
Mass Spectrometer ◽  
Cross Sections ◽  
Negative Ions ◽  
Total Cross Sections ◽  
Positive Ions ◽  
Wide Range

scholarly journals Fullerene Negative Ions: Formation and Catalysis

2020 ◽  
Author(s):  
Zineb Felfli ◽  
Kelvin Suggs ◽  
Nantambu Nicholas ◽  
Alfred Z. Msezane
Keyword(s):  
Transition State ◽  
Cross Sections ◽  
Water Oxidation ◽  
Regge Pole ◽  
Negative Ions ◽  
Negative Ion ◽  
Total Cross Sections ◽  
Hydrogen Bond Strength ◽  
Low Energy Electron ◽  
Fundamental Mechanism

We first explore negative-ion formation in fullerenes C44, C60, C70, C98, C112, C120, C132 and C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Water oxidation to peroxide and water synthesis from H2 and O2 are then investigated using the anionic catalysts C44ˉ to C136ˉ. The fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening in the transition state. DFT transition state calculations found C60ˉ numerically stable for both water and peroxide synthesis, C100ˉ increases the energy barrier the most and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

scholarly journals Role of Negative Ion Resonances in Electron Scattering from Atoms and Molecules

1999 ◽  
Vol 52 (3) ◽  
pp. 473 ◽  
Author(s):  
S. J. Buckman ◽  
D. T. Alle ◽  
M. J. Brennan ◽  
P. D. Burrow ◽  
J. C. Gibson ◽  
...  
Keyword(s):  
Electron Scattering ◽  
Cross Sections ◽  
Negative Ions ◽  
Negative Ion ◽  
Electron Correlations ◽  
Molecular Systems ◽  
Atoms And Molecules ◽  
Wide Range ◽  
Scattering Cross Sections

Transient negative ions (resonances) formed during the collision of an electron with an atom or molecule have been extensively studied for over thirty years. The continued interest in these states, both experimentally and theoretically, stems from the profound effects that they can have on electron scattering cross sections and the role that electron–electron correlations play in their formation and quasi-stability. A selective discussion of examples of such resonances, involving one, two and three excited electrons is given for a wide range of atomic and molecular systems.

FREE RADICALS BY MASS SPECTROMETRY: XI. THE MERCURY PHOTOSENSITIZED DECOMPOSITION OF C2–C4 OLEFINS

1956 ◽  
Vol 34 (6) ◽  
pp. 701-715 ◽  
Author(s):  
F. P. Lossing ◽  
D. G. H. Marsden ◽  
J. B. Farmer
Keyword(s):  
Mass Spectrometry ◽  
Free Radicals ◽  
Hydrogen Atom ◽  
Mass Spectrometer ◽  
Cross Sections ◽  
Methyl Radicals ◽  
Allyl Radical

The mercury photosensitized (Hg3P1) decomposition of olefins has been examined using a reactor coupled directly to a mass spectrometer. The primary split of ethylene has been shown to be predominantly molecular, and that of propylene mainly into an allyl radical and a hydrogen atom. With 1-butene the split is predominantly at a C–C bond giving allyl and methyl radicals, although a rupture of a C–H bond occurs as well. With 2-butene and isobutene a C–H bond is broken. It is concluded that the allyl and methallyl radicals produced have large cross sections for reaction with excited mercury atoms.

scholarly journals Fullerene Negative Ions: Formation and Catalysis

2020 ◽  
Vol 21 (9) ◽  
pp. 3159
Author(s):  
Zineb Felfli ◽  
Kelvin Suggs ◽  
Nantambu Nicholas ◽  
Alfred Z. Msezane
Keyword(s):  
Transition State ◽  
Cross Sections ◽  
Water Oxidation ◽  
Density Functional ◽  
Regge Pole ◽  
Negative Ions ◽  
State Density ◽  
Negative Ion ◽  
Functional Theory ◽  
Total Cross Sections

We first explore negative-ion formation in fullerenes C44 to C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Then, the formed negative ions C44ˉ to C136ˉ are used to investigate the catalysis of water oxidation to peroxide and water synthesis from H2 and O2. The exploited fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening/breaking in the transition state. Density Functional Theory transition state calculations found C60ˉ optimal for both water and peroxide synthesis, C100ˉ increases the energy barrier the most, and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

scholarly journals Distribution and formation of particles produced by laser ablation of cyclotetramethylene tetranitramine

2017 ◽  
Vol 35 (3) ◽  
pp. 391-396 ◽  
Author(s):  
W. Zhang ◽  
R. Shen ◽  
Y. Ye ◽  
L. Wu ◽  
P. Zhu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Laser Ablation ◽  
Solid State ◽  
Mass Spectrometer ◽  
Time Of Flight ◽  
Negative Ions ◽  
Solid State Laser ◽  
Laser Initiation ◽  
Positive Ions ◽  
Cyclotetramethylene Tetranitramine

AbstractAn experimental investigation into laser ablation of secondary explosives, cyclotetramethylene tetranitramine (HMX), has been carried out by using a solid-state laser at the wavelength of 1064 nm. The ion particles of decomposition were detected by using a time-of-flight mass spectrometer. Possible attributions of both negative ions and positive ions were obtained. Some obvious peaks were found atm/z= 18, 28, 46, 60, and 106, corresponding to H2O, CO/N2/H2CN, NO2, CH2NO2/N2O2, and N(NO2)2/CH2(NO2)2, respectively. According to the distribution of the particles, three possible pathways were proposed to explain the process of particles. The results may shed some light on the possible decomposition mechanism of HMX under laser initiation.

Formation of ground and excited hydrogen atoms in proton–rubidium inelastic scattering

2016 ◽  
Vol 94 (4) ◽  
pp. 431-436
Author(s):  
S.A. Elkilany
Keyword(s):  
Inelastic Scattering ◽  
Cross Sections ◽  
Incident Energy ◽  
Computer Code ◽  
Inelastic Collisions ◽  
Hydrogen Atoms ◽  
Total Cross Sections ◽  
Rubidium Atoms ◽  
Wide Range ◽  
First Time

Inelastic collisions of protons with rubidium atoms are treated for the first time within the framework of the three channel coupled static, and frozen core approximations. The method is used for calculating partial and total cross sections with the assumption that only three channels (elastic; non-excited hydrogen, 1s-state; and excited hydrogen, 2s-state) are open. We have used the Lipmann–Schwinger equation and the Green’s functions iterative numerical method technique to solve the derived coupled integro-differential equations to obtain the computer code. The present results for total hydrogen formation cross sections are in agreement with results of other available ones in a wide range of incident energy.

scholarly journals A new process of negative ion formation III―The energy distribution of the negative ions and accommodation coefficients of the positive ions

1937 ◽  
Vol 158 (893) ◽  
pp. 157-166 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Kinetic Energy ◽  
Energy Distribution ◽  
Negative Ions ◽  
Negative Ion ◽  
Charged Surface ◽  
Positive Ions ◽  
Wide Range ◽  
New Process ◽  
Accommodation Coefficients

In the previous paper it has been shown that the negative ions found in hydrogen, nitrogen, oxygen, and carbon dioxide are formed from positive ions which acquire two electrons from a negatively-charged surface, and are then accelerated away from the surface as negative ions. It will be shown in this paper that the negative ions come off the surface on which they are formed with a wide range of energy, extending from zero up to beyond 60 volts for O - and beyond 109 volts for H - . This energy is derived from the parent positive ions which have 200 volts’ kinetic energy on striking the surface.

scholarly journals Formation of 2s-State Hydrogen Atom in Proton-Lithium Inelastic Scattering

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
S. A. Elkilany
Keyword(s):  
Cross Sections ◽  
Lithium Atom ◽  
Variational Calculation ◽  
Polarization Potential ◽  
Total Cross Sections ◽  
The Core ◽  
Theoretical Approaches ◽  
Expansion Technique ◽  
Wide Range ◽  
Reliable Representation

Elaborate coupled static formalism is employed for treatment of proton-lithium collisions at wide range of incident energies between 10 and 1000 Kev. Coupled static and frozen core approximations are employed for calculating partial and total cross sections. Only elastic and formation of excited hydrogen, H(2s), channels are considered. Total cross sections are calculated using seven partial waves Green’s function expansion technique of total angular momentum ℓ  (0≤ℓ≤6). Proposed iterative approach allows for reliable representation of the core potentials using elaborate variational calculation of target orbitals. Polarization potential of lithium atom is taken into consideration in calculating corresponding total cross sections. Quite interesting reliable results were obtained in comparison with other theoretical approaches.

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