scholarly journals Numerical Simulations and the Design of Magnetic Field-Enhanced Electron Impact Ion Source with Hollow Cylinder Structure

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Guochen Qi ◽  
Di Tian ◽  
Guolun Gao ◽  
Guangda Liu ◽  
Chunling Qiu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Impact ◽  
Hollow Cylinder ◽  
Impact Ionization ◽  
Transmission Efficiency ◽  
Ion Source ◽  
Ionization Efficiency ◽  
Negative Ion ◽  
Ionization Source ◽  
Electron Intensity

An electron impact ion source-adopted magnetic field-enhanced technology has been designed for enhancing the electron intensity and the ionization efficiency. Based on the ion optic focus mechanism, an electron impact ionization source was designed, and the electron entrance into the ionization chamber was designed with a hollow cylinder structure to improve the ion extraction efficiency. Numerical simulation and optimal geometry were optimized by SIMION 8.0 to provide higher electron intensity and ion transmission efficiency. To improve the electron intensity, the influence of the filament potential and magnetic intensity was investigated, and the values of 70 eV and 150 Gs were chosen in our apparatus. Based on the optimal parameters, the air in the lab and oxygen gas was detected by the homemade apparatus, and the ion intensity was detected in the positive and negative ion modes, respectively. The homemade electron impact ion source apparatus has the potential to enhance ionization efficiency applied in the mass spectrometer ionization source.

Negative Ionen durch Elektronenstoß an einigen organischen Schwefelverbindungen

1966 ◽  
Vol 21 (8) ◽  
pp. 1251-1259 ◽  
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Electron Impact ◽  
Electron Capture ◽  
Chemical Reactions ◽  
Hydrogen Sulphide ◽  
Negative Ions ◽  
Ion Source ◽  
Ionization Efficiency ◽  
Dissociative Electron Capture ◽  
Negative Ion ◽  
Electron Affinities

Negative ion formation by electron impact has been studied in hydrogen sulphide, methylmercaptan, phenylmercaptan, benzylmercaptan, allylmercaptan, dimethylthioether, dimethyldisulphide and diallyldisulpbide. Appearance potentials, ionization efficiency curves and the kinetic energies of negative ions were measured by using a Fox ion source. The energies of various dissociative electron capture processses are discussed and electron affinities of some radicals of the types RS and RS2 are derived. Two chemical reactions of the CH2S- ion with dimethyldisulphide have been detected.

Negative Ionen durch Elektronenstoß aus organischen Nitroverbindungen, Äthylnitrit und Äthylnitrat

1967 ◽  
Vol 22 (5) ◽  
pp. 700-704
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Molecular Ions ◽  
Ion Source ◽  
Negative Ion ◽  
Electron Affinities ◽  
Low Intensity ◽  
Ion Molecule Reactions ◽  
Fragment Ions ◽  
Product Ions

Negative ion formation by electron impact has been studied in nitromethane, nitroethane, nitrobenzene, tetranitromethane, ethylnitrite and ethylnitrate. Appearance potentials, ionization efficiency curves and kinetic energies of negative ions were measured by using a Fox ion source. The electron affinities of C2H5O and of C (NO2)3 are discussed as well as the energetics of processes which yield NO2-. The electron capture in nitrobenzene and tetranitromethane leads to molecular ions [C6H5NO2~ in high, C (NO2)4 in very low intensity] besides many fragment ions. A number of product ions from negative ion-molecule reactions has also been found.

Energetics of the Ionization and Fragmentation of Phosphorus Trifluoride by Electron Impact

1975 ◽  
Vol 53 (6) ◽  
pp. 933-938 ◽  
Author(s):  
David F. Torgerson ◽  
John B. Westmore
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Ionization Efficiency ◽  
Negative Ion ◽  
Efficiency Curve ◽  
Group V ◽  
Fragmentation Pathways ◽  
Ion Fragmentation ◽  
Positive Ions ◽  
Significant Intensity

Relative intensities and appearance potentials of several positive ions in the mass spectrum of PF3 are reported as well as an ionization efficiency curve for F−, the only negative ion of significant intensity. Probable ion fragmentation pathways are proposed, together with heats of formation of some positive ions, and ionization potentials for PF3, PF2·, and PF. The results are compared with available data for other Group V halides.

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