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Instrumentation for Energy-Loss Spectroscopy

  • Ray F. Egerton
Chapter

Abstract

To characterize a specimen completely in terms of its inelastic scattering, it would be necessary to record the scattered intensity J(x, y, θ x , θ y , E) as a function of position (specified by coordinates x and y) on the specimen, as a function of the coordinates of angular deflection θ x and θ y , and as a function of energy loss E. Even if such a procedure were technically feasible, it would involve storing a very large amount of data, so in practice an energy-loss experiment records one of the following:
  1. (a)

    The intensity J(x, y) or J(θ x , θ y ), for a given value of E or a specified range of energy loss. These data correspond to an energy-filtered image or diffraction pattern, and can be obtained using either scanning-beam (STEM) or fixed-beam (CTEM) techniques, as discussed in Section 2.4.

     
  2. (b)

    The intensity J(E) at a given point on the specimen or, more precisely, ∫ J(E) dx dy, where the limits of integration are defined by x2 + y2 = d2/4, d being the diameter of the incident beam. Here were are referring to energy-loss spectroscopy (or energy analysis) carried out using a double-focusing spectrometer such as the magnetic prism (Sections 2.1.1 and 2.2).

     
  3. (c)

    The intensity J(y, E) for a fixed value of the spatial coordinate x, or J(θ y , E) for a given θ x . This involves energy analysis along a line drawn through the specimen or its diffraction pattern and requires a spectrometer which focuses only in the direction of dispersion, such as the Möllenstedt analyzer (Section 2.1.4) or the Wien filter (Section 2.1.3).

     

Keywords

Energy Resolution Wien Filter Chromatic Aberration Fringe Field Readout Noise 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • Ray F. Egerton
    • 1
  1. 1.University of AlbertaEdmontonCanada

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