Negative Ionen durch Elektronenstoß an einigen organischen Schwefelverbindungen

1966 ◽  
Vol 21 (8) ◽  
pp. 1251-1259 ◽  
Author(s):  
K. Jäger ◽  
A. Henglein

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.

1967 ◽  
Vol 22 (5) ◽  
pp. 700-704
Author(s):  
K. Jäger ◽  
A. Henglein

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Guochen Qi ◽  
Di Tian ◽  
Guolun Gao ◽  
Guangda Liu ◽  
Chunling Qiu ◽  
...  

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.


1994 ◽  
Vol 354 ◽  
Author(s):  
Junzo Ishikawa

AbstractNegative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected without a charge neutralizer in these fabrication processes. Scatter-less negative-ion implantation into powders is also possible. For this purpose an rf-plasma-sputter type heavy negative-ion source was developed, which can deliver several milliamperes of various kinds of negative ion currents such as boron, phosphor, silicon, carbon, copper, oxygen, etc. A medium current negative-ion implanter with a small version of this type of ion source has been developed.


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