ChemInform Abstract: EXCITED STATES AND POSITIVE IONS OF SULFUR HEXAFLUORIDE

1977 ◽  
Vol 8 (20) ◽  
pp. no-no
Author(s):  
P. J. HAY
Keyword(s):  
Excited States ◽  
Sulfur Hexafluoride ◽  
Positive Ions

Excited-Atom Production by Electron Bombardment of Alkali-Halides

1986 ◽  
Vol 75 ◽  
Author(s):  
R. E. Walkup ◽  
Ph. Avouris ◽  
A. P. Ghosh
Keyword(s):  
Gas Phase ◽  
Excited States ◽  
Ground State ◽  
Excited Atom ◽  
Alkali Halides ◽  
Electron Bombardment ◽  
Secondary Electrons ◽  
Excited Atoms ◽  
Positive Ions ◽  
Electronically Excited

AbstractWe present experimental results which suggest a new mechanism for the production of excited atoms and ions by electron bombardment of alkali-halides. Doppler shift measurements show that the electronically excited atoms have a thermal velocity distribution in equilibrium with the surface temperature. Measurements of the absolute yield of excited atoms, the distribution of population among the excited states, and the dependence of yield on incident electron current support a model in which excited atoms are produced by gas-phase collisions between desorbed ground-state atoms and secondary electrons. Similarly, gas-phase ionization of ground-state neutrals by secondary electrons accounts for a substantial portion of the positive ions produced by electron bombardment of alkali-halides.

The excited states of biphenylene and its negative and positive ions

1963 ◽  
Vol 6 (3) ◽  
pp. 317-328 ◽  
Author(s):  
N.S. Hush ◽  
J.R. Rowlands
Keyword(s):  
Excited States ◽  
Positive Ions

Fracto-Emission from Interfacial Failure

1989 ◽  
Vol 153 ◽  
Author(s):  
J. T. Dickinson
Keyword(s):  
Crack Growth ◽  
Excited States ◽  
Charge Separation ◽  
Failure Modes ◽  
Ground States ◽  
Dissimilar Materials ◽  
Interfacial Failure ◽  
Neutral Species ◽  
Positive Ions ◽  
Fracture Of Materials

AbstractFracto-Emission is the emission of particles and photons during and after fracture of materials. The observed emission includes electrons, negative and positive ions, neutral species in both ground states and in excited states, and visible photons. This emission can often serve as a sensitive probe of crack growth and may prove to be a useful tool for investigating molecular and microscopic events accompanying crack growth and for studying the details of failure modes in a variety of materials. Interfacial failure provides unique fracto-emission signals due to the extensive charge separation accompanying separation of dissimilar materials. Here we present the results of several recent studies of interfacial failure involving a variety of materials and relate them to electronic and mechanical processes accompanying failure.

Electronic Structure of the Transition Elements

1973 ◽  
Vol 51 (6) ◽  
pp. 644-647
Author(s):  
K. M. S. Saxena ◽  
S. Fraga
Keyword(s):  
Electronic Structure ◽  
Excited States ◽  
Ground State ◽  
Ground States ◽  
Negative Ions ◽  
State Function ◽  
Transition Elements ◽  
Hartree Fock ◽  
Positive Ions ◽  
Single Set

Numerical Hartree–Fock functions have been determined for the ground states and first excited states of the configurations 3dN4s0 and 3dN4s2 for the negative ions, neutral atoms, and first four positive ions of all the transition elements. The validity of the approximation, embodied in the use of a single set of parameters determined from the ground state function of a configuration for the prediction of the spectroscopic levels arising from it, has been examined in detail in the case of Fe I, 3d64s2, where independent calculations have been carried out for all the excited states.

scholarly journals Nachlieferung von Elektronen beim Entladungsaufbau in Wasserstoff und Sauerstoff für E/p von 60 bis 3000 Volt/cm Torr

1967 ◽  
Vol 22 (3) ◽  
pp. 347-354
Author(s):  
H. Schlumbohm
Keyword(s):  
Excited States ◽  
Charge Exchange ◽  
Electronic States ◽  
Single Electron ◽  
Secondary Electrons ◽  
Electron Collisions ◽  
Positive Ions ◽  
Additional Process ◽  
Electron Avalanches ◽  
Ion Species

By analysing the temporal current shapes of electron avalanches the different secondary ionisation processes occuring in H2- and O2-discharges have been separated and data taken. In hydrogen at E/p < 250 volts/cm Torr secondary electrons are released at the cathode by photons emitted mainly from excited states of the WERNER-bands of the H2-molecule. In oxygen secondary electrons are released both within the gas and at the cathode at E/p < 500 volts/cm Torr by photons from electronic states above the first ionisation level of the O2-molecule, which are excited by single electron collisions.With increasing E/p additional secondary electrons in hydrogen are produced by positive ions at the cathode, but for E/p > 170 volts/cm Torr the avalanche currents cannot be interpreted by the photon and ion processes thus indicating the action of a third mechanism. The same result was obtained for oxygen at E/p > several 100 volts/cm Torr. This additional process is discussed on the basis of different ion species and a possible action of fast neutral molecules resulting from charge exchange collisions.

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