The dissociative excitation of cobalt atom even sextet levels in collisions of electrons with CoCl2 molecules

The cross sections of dissociative excitation of 46 transitions from cobalt atom even sextet levels in collisions of electrons with CoCl₂ molecules were measured at an exciting electron energy of 100 eV. The dissociative and direct CoI excitation cross sections were compared. The results were used to calculate the total cross sections of dissociative excitation of CoI levels at an electron energy of 100 eV. Possible reaction channels at low electron energies are discussed.     

Dissociative excitation of even triplet and quintet levels of the iron atom in collisions of electrons with iron diiodide molecules

The method of extended crossing beams is used to study inelastic collisions of slow electrons with iron dichloride molecules. The dissociative excitation of even triplet and quintet levels of the iron atom at the incident electron energy of 100 eV is examined. The resulting dissociative excitation cross sections are compared to the cross sections of the excitation of FeI in electron-atom collisions.     

Inelastic collisions of slow electrons with yttrium trichloride molecules

Inelastic collisions of electrons with YCl₃ molecules are investigated by the method of extended crossing beams. As in the case of LaCl₃ molecules, only the spectral lines of singly charged metal ions are found, with the lines of yttrium atoms and the spectral bands of yttrium monochloride being absent. The excitation cross sections of the energy levels of Y(II) and the contribution of the cascade population are calculated using the results obtained. Possible reaction channels upon dissociative excitation are discussed.     

Dissociative excitation of the odd quartet <Emphasis Type="Italic">S,P, D</Emphasis>, and <Emphasis Type="Italic">F</Emphasis> levels of the manganese atom in e-MnCl<Subscript>2</Subscript> collisions

The dissociative excitation of the ⁴ S°, ⁴ P°, ⁴ D°, and ⁴ F° levels of the manganese atom in collisions of slow electrons iwth manganese dichloride molecules is studied experimentally. It is found that the dissociative excitation cross sections for these levels are larger than the cross sections of direct excitation in the e-Mn collisions. The cross section ratios of the electron-atom and electron-molecule collisions, which characterize the effect of the chemical bond of the manganese atom with the halogen on the absolute excitation cross sections, are determined.     

The dissociative excitation of odd doublet cobalt atom levels in collisions of electrons with cobalt dichloride molecules

The extended crossed beam method was used to measure the dissociative excitation cross sections in e-CoCl₂ collisions for 91 transitions from odd doublet levels of cobalt atoms. The dissociative and direct CoI excitation cross sections were compared. Possible reaction channels at low electron energies were considered. The results were used to calculate the total dissociative excitation cross section of CoI levels at an exciting electron energy of 100 eV. For the z ² F°, z ² G°, and y ² G° levels, cascade population contributions were also determined.     

The dissociative excitation of singlet levels of the singly charged lanthanum ion in collisions of electrons with lanthanum bromide molecules

The method of extended crossing beams was used to study inelastic collisions of slow electrons with LaBr₃ molecules. Dissociative excitation caused the appearance of spectral lines of the singly charged lanthanum ion. 38 dissociative excitation cross sections of LaII spectral lines (upper singlet levels) were studied at a 100 eV exciting electron energy. Three optical excitation functions were recorded over the electron energy range 0–100 eV. The cross sections obtained are compared with the data on dissociative excitation cross sections of the LaCl₃ molecule.     

The Dissociative Excitation of MnII and MnBr in Collisions of Electrons with MnBr2 Molecules

Inelastic collisions of MnBr₂ molecules with a beam of monoenergetic electrons with the formation of the single-charged atomic manganese ion and the MnBr molecule in excited states were studied experimentally. The cross sections of the dissociative excitation of MnII in electron-MnBr₂ collisions and direct excitation in electron-Mn collisions were compared. Possible channels of the reaction of Mn₊* formation are discussed.     

The dissociative excitation of singlet and quintet nickel atom states in e-NiBr<Subscript>2</Subscript> collisions

The dissociative excitation of singlet and quintet nickel atom states in e-NiBr₂ collisions was studied by the method of extended intersecting beams. Optical excitation functions over the electron energy range 0–100 eV were recorded for most of the spectral lines observed. Possible dissociative excitation channels at low electron energies were discussed. The cross sections of dissociative and direct excitations and dissociative excitations of the NiBr₂ and NiCl₂ molecules were compared.     

Dissociative excitation of the singly charged manganese ion in collisions of electrons with manganese diiodide molecules

The dissociative excitation of the singly charged manganese ion in collisions of electrons with MnI₂ molecules is experimentally studied. At exciting electron energy of 100 eV, 16 dissociative excitation cross sections were measured. The studied transitions occur within the quintet and septet term systems in the absence of intercombination transitions. The measured values of the cross sections are compared to similar values obtained previously in studies of e–MnCl₂ and e–MnBr₂ collisions.     

Dissociative excitation of odd quintet levels of the iron atom by collisions of electrons with iron dichloride molecules

The dissociative excitation of odd quintet levels of the iron atom by collisions of slow electrons with iron dichloride molecules was studied using the method of extended crossing beams. Fifty-five dissociative excitation cross sections were measured at an excitation electron energy of 100 eV. Five optical excitation functions were recorded over an electron energy range from 0 to 100 eV. Some tendencies in the behavior of dissociative excitation cross sections were discussed.     

Dissociative excitation of even states of tin atoms in e-SnCl2 collisions

Dissociative excitation of even levels of tin atoms in collisions of slow electrons with tin dichloride molecules is studied experimentally. The levels studied belong to the configurations 5s ²5pnp ^{1, 3} L (n=6, 7; L=S, P, D) and 5s ²5p 4f. Absolute values of cross sections for dissociative excitation at the electron energy of 100 eV are 1.05–2.56 times greater than cross sections for excitation in electron-atom collisions at the energy of 50 eV.     

Dissociative excitation cross sections of the lead atom in collisions between electrons and PbI2 molecules

Dissociative excitation of the lead atom in e-PbI₂ collisions has been studied experimentally. 27 excitation cross sections were measured for an energy of the exciting electrons equal to 100 eV. Nine optical excitation functions were recorded with variation of the electron energy in the range 0–100 eV. The most probable reaction channels for low electron energies are discussed, as well as the ratio of the dissociative excitation cross sections for the lead atom in e-PbI₂ and e-PbCl₂ collisions. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 701–706, November–December, 2006.     

The dissociative excitation of doublet and sextet manganese atom levels in collisions of electrons with manganese dibromide molecules

Inelastic collisions of electrons with manganese dibromide molecules were studied by the method of extended crossing beams. These collisions cause the formation of excited manganese atoms in doublet and sextet states. At an exciting electron energy of 100 eV, 52 dissociative excitation cross sections were measured. At electron energies 0–100 eV, three optical excitation functions were recorded. The ratio between excitation cross sections in electron-molecular and electron-atomic collisions is considered.     

Processes of dissociative excitation in collisions of electrons with CaI<Subscript>2</Subscript> molecules

The dissociative excitation of calcium atoms and ions and calcium monoiodide in e-CaI₂ collisions was studied by the method of extended crossing beams. The excitation cross sections of calcium atoms and ions in electron-atom and electron-molecule collisions are compared. The main channels of the reactions at low electron energies are discussed.     

Dissociative Excitation of the Odd Sextet Levels of the Cobalt Atom by Collisions of Electrons with Cobalt Dichloride Molecules

Inelastic collisions of slow electrons with cobalt dichloride molecules, leading to the formation of excited cobalt atoms in odd sextet states, are experimentally studied. At an incident electron energy of 100 eV, thirty six dissociative excitation cross sections are measured for levels belonging to the z⁶D°, z⁶F°, and z⁶G° terms. In the electron energy range of 0–100 eV, ten optical excitation functions are recorded. The full cross sections for the dissociative excitation of the cobalt atom levels and the contribution of cascade transitions to their population are determined. The cross sections for electron–molecule and electron–atom collisions are compared.     

Excitation of singlet levels of a singly charged scandium ion in e-Sc collisions

The excitation of singlet levels of the singly charged scandium ion is experimentally studied in collisions of slow electrons with scandium atoms. At the exciting electron energy of 30 eV, 59 excitation cross sections are measured. In the electron energy range of 0–200 eV, seven optical excitation functions are recorded. On the basis of these data the total excitation cross sections are calculated for 11 even and 9 odd levels of Sc II, as well as the contribution of cascade population to 8 even and 7 odd levels.     

Dissociative excitation of doublet and octet levels of the manganese atom in collisions of electrons with manganese diiodide molecules

The dissociative excitation of doublet and octet levels of the manganese atom in collisions of slow electrons with manganese diiodide molecules is studied. At the exciting electron energy of 100 eV, the excitation cross sections for 28 and 12 transitions, respectively, from doublet and octet states of manganese atom are measured. In the exciting electron energy range of 0–100 eV, six optical excitation functions are recorded. The possible channels of the formation of excited manganese atoms at low electron energies are discussed.     

Inelastic collisions of slow electrons with SrBr<Subscript>2</Subscript> molecules

Inelastic collisions of slow electrons with SrBr₂ molecules were studied experimentally. The dissociative excitation cross sections of two lines of the strontium atom and eight lines of the singly charged strontium ion were measured. Six optical excitation functions were recorded over the electron energy range 0–100 eV. Dissociative excitation cross sections were also measured for two strontium monobromide sequences related to the B ²Σ⁺-X ²Σ⁺ system.     

Dissociative excitation due to collisions of electrons and helium ions with oxygen molecules

The absolute cross sections of luminescence related to atomic and ionic oxygen at dissociative excitation through e-O₂ and He⁺-O₂ collisions are determined. An intense OII line (83.4 nm) is discovered. For e-O₂ collisions, a weak OIII line (70.5 nm) is found. Experimental data for He⁺-O₂ collisions are qualitatively interpreted in terms of the quasi-diatomic approximation.     

Account of the fine structure of hydrogen atom levels in the effective emission cross sections of Balmer lines excited by electron impact in gases and plasma

The possibility of a correct account of the fine structure was shown for two limiting cases observed in beam and plasma experiments. A significant difference was found in the emission cross sections and the rate coefficients of direct and dissociative excitation of the H _α and H _β lines by electron impact in two limiting cases (e.g., this difference reaches an order of magnitude for dissociative excitation of the H _β line). The most reliable data on the cross sections and the rate coefficients of direct and dissociative excitation of the H _α and H _β lines by electron impact were found for both limiting cases. It was shown that, among the first four lines of Balmer series (rather easily detected), only the first two lines, i.e., H _α and H _β, can be currently employed in plasma spectroscopy studies because of the absence of data on the partial excitation cross sections of hydrogen atom nl-sublevels with n≥5.