Grzegorz Kasperski

Absolute total cross section measurements for electron scattering on benzene molecules

The absolute total cross section for electron scattering on C,H, molecules has been measured in two distinct electron-transmission experiments for impact energies between 0.6 eV and 3.5 keV. The present results are compared with other total cross section experimental data.

Electron scattering from hexafluoride molecules: WF6 and C2F6. Absolute total cross section measurements from 1 to 250 eV

Electron-scattering absolute total cross sections for tungsten hexafluoride (WF6) and hexafluorethane (C2F6) molecules have been measured in a linear transmission electron-beam experiment within the impact energy range from about 1 to 250 eV. For electron scattering from WF6 the cross section shows a prominent resonant-like peak centred at 3 eV and a very broad enhancement in the energy range between 20 and 70 eV overlaid with some much less pronounced features. The cross section for C2F6 has two resonant structures at 5 and 9 eV, respectively, and a very broad hump ranging from 20 to 60 eV with a distinct shoulder near 20 eV. Comparison of the e--C2F6 total cross section with available low-energy data from other experiments is made. The effect of fluorination is indicated.

Electron collisions with trifluorides: BF3 and PF3 molecules

Absolute total cross sections (TCSs) for electron scattering from boron trifluoride (BF(3)) and phosphorus trifluoride (PF(3)) molecules have been measured using a linear transmission method. The electron energy ranges from 0.6 to 370 eV for BF(3) and from 0.5 to 370 eV for PF(3). The TCS energy dependence for BF(3) exhibits two very pronounced enhancements: resonantlike narrow feature located near 3.6 eV with the maximum value of 19.2 x 10(-20) m(2), and intermediate energy very broad enhancement with two humps, one centered around 21 eV (18.8 x 10(-20) m(2) in the maximum) and the other near 45 eV (19.5 x 10(-20) m(2)). For PF(3) the TCS has quite different low-energy dependence: at 0.5 eV it has a high value of 70 x 10(-20) m(2) and decreases steeply towards higher energies. Beyond the minimum near 5.5 eV, the TCS reveals two distinct humps: the resonant one centered near 11 eV with the peak value of 32.9 x 10(-20) m(2) and the second one much broader around 35 eV (27.9 x 10(-20) m(2)). The present TCSs for trifluorides are compared to each other as well as to previous TCS data for selected perfluorides and to results for their perhydrided counterparts. The differences and similarities in the shape and magnitude of TCSs are pointed out.

Experimental absolute total cross sections for low-energy electron collisions with tetrahedral compounds of germanium:

Absolute total cross section (TCS) of the electron collision with molecules has been measured in a linear transmission experiment for impact energies from 0.5 to 250 eV. The TCS function is dominated by a steep rise towards low energies below 3 eV. At energies above the minimum at 3 eV the TCS shows another enhancement spanned up to about 70 eV on which some resonant-like features are visible: the maximum centred near 6.5 eV and two weak peaks at 16 and 25 eV, respectively. A comparison with the recent measurements taken in the same laboratory for and and for other targets of the same symmetry is made to search for similarities and/or differences between electron scattering TCSs for tetrahedral molecules. The data demonstrate that the general shape of the low-energy TCS for tetrahedral molecules depends on external rather than on central atoms.

Low- and intermediate-energy total electron scattering cross sections for and molecules

Absolute total cross sections for electron collision with and molecules have been measured in a linear attenuation experiment for impact energies ranging from 0.6 to 250 eV. Good agreement of the present results with other experimental data has been found in respect of the energy dependence of the total cross section (TCS). Discrepancies in magnitude are only apparent for the lowest and the highest impact energies applied. Comparison is also made with theoretical calculations. The electron-scattering TCS for shows two distinct resonant maxima: one at 1.7 eV, occurring over a narrow energy range, the other - much broader - near 9 eV. No TCS data for are available for comparison.

Absolute total cross-section measurements for electron scattering from silicon tetrachloride, SiCl\(\), molecules

Abstract:The absolute total cross-sections for electron scattering on SiCl4 molecules have been measured in two distinct electron-transmission experiments, in Gdansk and in Trento laboratory, for impact energy ranging from 0.3 to 250 eV and from 75 to 4000 eV, respectively. The e--SiCl4 total cross-section function shows two very distinct resonant-like features: the strong peak at 1.9 eV and much broader main maximum centered near 10 eV with some additional substructure close to 5 eV. The present results are compared with low-energy total experimental data and elastic theoretical calculations for electron collisions with silicon tetrachloride molecules.

Electron collisions with germane molecules. Absolute total cross section measurements from 0.75 to 250 eV

Absolute total cross section for electron collisions with molecules has been measured in a linear electron transmission experiment for impact energies between 0.75 eV and 250 eV. Experimental cross section function versus energy reveals a resonant-like broad enhancement with maximum between 3 and 4 eV, monotonically decreasing at higher energies.

Total cross section measurements for electron scattering on silicon tetrafluoride

Abstract Total cross sections for electron scattering on SiF 4 have been measured between 0.6 and 3500 eV. An absolute transmission method has been used on two different apparatuses. Evidence for a Ramsauer minimum is found at about 1 eV collision energy. A discussion is given of possible resonant states at low energies.

Electron scattering from disilane (Si2H6) molecules. Absolute total cross section measurements from 1 to 370 eV

Absolute grand total cross sections (TCSs) for electron-disilane (Si2H6) scattering have been measured over the energy range from 1 to 370 eV in a linear transmission experiment. The low-energy TCS is dominated by a broad resonant-like enhancement. In the region of the maximum the present grand TCS values appeared to be distinctly lower than previously reported integral elastic cross section data. A comparison of total electron scattering cross sections for the two simplest silicon hydrides and relevant hydrocarbons is given.

Absolute electron-scattering total cross section measurements for methanethiol molecule, CH3SH, from 0.6 to 250 eV

The absolute total cross section for electron scattering on CH3SH molecules has been measured in a linear electron-transmission experiment for impact energies between 0.6 eV and 250 eV. No theoretical or experimental total cross section data are available for comparison. The obtained total cross section has an energy dependence which is typical for polar molecules. Static electric dipole polarizability of methanethiol has been estimated using a correlation of electron-scattering total cross section with target polarizability. The polarizability of CH3SH thus obtained is in good agreement with values derived by empirical methods.