Interaction Of Slow Electrons Research Articles

Interaction of Slow Electrons with Surfaces

A review of the basic concepts of the interaction between slow electrons with energies between 10 and 103 eV and surfaces is presented. First, the solid is considered to consist of an electron gas with a charge compensating, spatially constant positive background (jellium) or of an assembly of completely randomly distributed atoms with truncated potentials (randium). Next the influence of the periodic nature of the solid on the interaction process is taken into account (diffraction). Finally, the effects associated specifically with the presence of the surface are discussed.

The interactions of slow electrons with molecules

The interactions of slow electrons with molecules

Interaction of Slow Electrons with Insulating Crystals. I. Absorption Coefficient for Cleaved Alkali Halides; Experimental Techniques

Techniques have been developed that will permit a unique determination of an absorption coefficient δa for 0.2- to 20-ev electrons on cleaved, insulating crystals. Two classes of electron trapping levels, one that empties rapidly and one that does not empty at room temperature, may exist in the target and if they do, effects caused by them may perturb the data. Experimental techniques were developed to compensate for each characteristic effect. Pure and nonstoichiometric KBr and KCl crystals were studied. The probability that a crystal-incident electron results in a charge influx was found to vary makedly as a function of the impact energy and in a manner characteristic of the target. This feasibility study indicates that slow electron beams could be a powerful tool for diagnosing surface and bulk properties of insulating crystals.

Interaction of Slow Electrons With Insulating Crystals. 2. Comparison of Electron and Photon Absorption Coefficients for KCl and KBr

The electron absorption coefficient for pure KCl and additively colored KCl and KBr was measured in the energy range from 0.2 to 12 ev. These data are compared with photon absorption measured in the same crystals in the energy range from 1.2 to 6.5 ev and with published optical and photoemission data above 6.5 ev. Certain imperfection interactions were found at corresponding photon and electron energies. The surface transition layer, even for pure KCl, was observed to contain $F$ and ${V}_{3}$ centers. There was no evidence of direct electron-exciton interactions. The valence band of KCl was observed to be 8.6\ifmmode\pm\else\textpm\fi{}0.2 ev below the vacuum level; this agrees with Eby, Teegarden, and Dutton's measurements. Upon electron bombardment, an optical absorption near the first fundamental band was found to develop. Its characteristics do not coincide with any of the absorption bands previously reported in this energy region.

Interaction of Slow Electrons with Atomic Oxygen and Atomic Nitrogen

Abstract : The polarization potential for an electron in the field of an oxygen atom was determined by utilizing recent experimental results on the binding energy of 0(-). The corresponding polarization potential for atomic nitrogen was obtained from the results for oxygen by an extrapo lation based on the theory of polarization. From these results the photo cross section for 0(-) and the scattering cross section sections for oxygen and nitrogen were calculated. The photo cross section is in good agreement with experimental results. The scattering cross sections are compared with other recent calculations. It is also shown on the basis of the general theory of the photo cross section that the energy dependence of the cross section determines the scattering length for electron scattering. The agreement of the computed photo cross section with experiment therefore is a direct check on the scattering prediction. (Author)

Interaction of Slow Electrons and Surface Films of Ionic Crystals

Interaction of Slow Electrons and Surface Films of Ionic Crystals

Excitation Probability Functions of Atomic and Molecular Energy-Levels

IN the correlation of the electrical and spectroscopic properties of a glow discharge in a molecular or atomic gas, the need for a rough quantitative analysis of the kinetics of the excitation of the gas soon becomes apparent. In all but the simplest cases, no more than a rough analysis can be attempted with the present scanty experimental and theoretical knowledge of the interaction of slow electrons with atoms and molecules. It is the purpose of this communication to present an empirical form for the excitation probability functions of the atomic and molecular levels which seems to fit the few experimental curves fairly closely, and at least provides a basis for calculation where previously only generalized discussion was possible.