Ultra-low energy electrons

In this section we apply the theory developed in the preceding sections to a series of experiments carried out by Schmitt et al using the so-called reaction microscope for ultra-low energy electrons emitted from neutral target atoms. This state of the art experimental technique has enabled experimentalists to measure simultaneously the momenta of the emitted electrons and the recoiling residual-target ion and many new striking features have been found. 

Oshima, A., F. Shiraki, H. Fujita andM. Washio. 2011. Surface modification of polymeric materials using ultra low energy electron beam irradiation. Radiat Phys Chem 80 196-200. 

The tools used for the experiments described below have been described in several books and review articles (1-3). Surface structure is determined by low energy electron diffraction (LEED), surface composition by Auger electron spectroscopy (AES), and reaction kinetics and mechanism by temperature programmed reaction spectroscopy (TPRS). Standard ultra-high vacuum technology is used to maintain the surface in a well-defined state. As this article is a consolidation of previously published work, details of the experiments are not discussed here. 

The main aim of this paper is to review the CDW-EIS model used commonly in the decription of heavy particle collisions. A theoretical description of the CDW-EIS model is presented in section 2. In section 3 we discuss the suitablity of the CDW-EIS model to study the characteristics of ultra-low and low energy electrons ejected from fast heavy-ion helium, neon and argon atom collisions. There are some distinct characteristics based on two-centre electron emission that may be identified in this spectrum. This study also allows us to examine the dependence of the cross sections on the initial state wave function of multi-electron targets and as such is important in aiding our understanding of the ionization process. 

Details of the emission of ultra-low and low energy electrons can be seen in the cross sections doubly differential in the longitudinal and transverse momenta. The formula for the double differential cross section as a function of the longitudinal electron velocity t>e for various transverse electron velocity Ve cuts can be obtained from equation (57) by noting that... 

The experiments were performed in two different ultra high vacuum (UHV) chambers using two different Pt(lll) single crystals. The X-ray photoelectron spectra were obtained in a chamber with a base pressure of lxlO" Torr. The system has been described in detail elsewhere. In brief, the UHV chamber is equipped with low energy electron diffraction (LEED), an X-ray photoelectron spectrometer (XPS), a quadrupole mass spectrometer (QMS) for temperature programmed desorption (TPD), and a Fourier transform infrared spectrometer (FTIR) for reflection absorption infrared spectroscopy (RAIRS). All RAIRS and TPD experiments were performed in a second chamber with a base pressure of 2 X 10 ° Torr. The system has been described in detail elsewhere. In brief, the UHV chamber is equipped for LEED, Auger electron spectroscopy (AES) and TPD experiments with a QMS. The chamber is coupled to a commercial FTIR spectrometer, a Bruker IFS 66v/S. To achieve maximum sensitivity, an... 

Tompkins (1978) concentrates on the fundamental and experimental aspects of the chemisorption of gases on metals. The book covers techniques for the preparation and maintenance of clean metal surfaces, the basic principles of the adsorption process, thermal accommodation and molecular beam scattering, desorption phenomena, adsorption isotherms, heats of chemisorption, thermodynamics of chemisorption, statistical thermodynamics of adsorption, electronic theory of metals, electronic theory of metal surfaces, perturbation of surface electronic properties by chemisorption, low energy electron diffraction (LEED), infra-red spectroscopy of chemisorbed molecules, field emmission microscopy, field ion microscopy, mobility of species, electron impact auger spectroscopy. X-ray and ultra-violet photoelectron spectroscopy, ion neutralization spectroscopy, electron energy loss spectroscopy, appearance potential spectroscopy, electronic properties of adsorbed layers. 

Gillis H P, Choutov D A, Martin K P, Bremser M D and Davis R F 1997 Highly anisotropic, ultra-smooth patterning of GaN/SiC by low energy electron enhanced etching in DC plasma J. Electron. Mater. 26 301-5... 

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