Energy backscatter

Particle- and energy-backscattering coefficients of light ions from solids. Distributions of energy and angle of scattered particles also are included (282 sets). 

The first objective is the measurement with good precision of cither the RCS of a complex shape or the reflection coefficient of a metallic plate covered with an absorbing material. The basic principle consists in lighting the object and measuring the electromagnetic energy backscattered from it. For that purpose, the measurement is made in a room named anechoi c chamber since all the walls are covered with pyramidal foam absorbers suppressing all parasitic reflections. 

Images with elemental contrast can be obtained by detecting the high energy backscattered electrons, whose intensity is a function of the atomic number of the elements in the sample. These electrons also have a greater penetration depth than secondary electrons and so can be used for studying buried structures. 

Interactions of high-energy backscattered electrons with specimen atoms... 

BSE are not much used in LVSEM, although the resolution and atomic number contrast are both good. There are many more secondaries than backscattered electrons at low voltage, and this is especially true for low atomic number samples such as polymers. It is also comparatively difficult to detect these few low energy backscattered electrons. A scintillator [40] or a multi-channel electron plate can detect them directly [41, 42]. Alternatively they can be detected indirectly, through the secondaries produced by their collision with the chamber walls (SE3) [30, 43]. 

D. P. Smith, Analysis of surface composition with low-energy backscattered ions. Surface Sci. 25, 171-191 (1971). 

LEED Low-energy electron diffraction [62, 75, 105] Elastic backscattering of electrons (10-200 eV) Surface structure... 

EXAFS Extended x-ray absorption fine structure [177, 178] Variation of x-ray absorption as a function of x-ray energy beyond an absorption edge the probability is affected by backscattering of the emitted electron from adjacent atoms Number and interatomic distance of surface atoms... 

Figure Al.7.12 shows the scattered electron kinetic energy distribution produced when a monoenergetic electron beam is incident on an A1 surface. Some of the electrons are elastically backscattered with essentially...

Heiland W and Taglauer E 1977 The backscattering of low energy ions and surface structure Surf. Sc/. 68 96-107... 

Taglauer E 1997 Low-energy Ion scattering and Rutherford backscattering Surface Analysis The Principal Techniques ed J C VIckerman (Chichester Wiley) pp 215-66... 

Rutherford backscattering spectrometry is the measurement of the energies of ions scattered back from the surface and the outer microns (1 micron = 1 pm) of a sample. Typically, helium ions with energies around 2 MeV are used and the sample is a metal coated silicon wafer that has been ion implanted with about a... 

Figure Bl.24.5. Backscattering spectrum of a thin Ni film (950 A) with near monolayers ( 30 x 10 at cm of An on the front and back surfaces of the Ni film. The signals from the front and back layers of An are shown and are separated in energy from each other by nearly the same energy width as the Ni signal.

Figure Bl.24.10. Random and aligned (chaimelled) backscattering spectrum from a single crystal sample of silicon. The aligned spectrum has a peak at the high energy end of the Si signal. This peak represents helium...

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