Elastic-recoil detection

In contrast to the RBS, the technique of detection of the recoiled (secondary) particles is called elastic recoil detection (ERD) which was first reported in 1976 by L Ecuyer et al. The ERD provides depth as well as mass information regarding the target particle location and therefore allows simultaneous profiling of all elements within the substrate. ERD is 

The ERD technique is a consequence of the conservation laws i.e., that the energy of the other participant in the collision, which is not detected in RBS (i.e., the target nuclei themselves), contains the same kind of information about the target. ERD is thus an accurate ion beam analysis technique specially suited for characterization (depth profiling) of light elements. 

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Forward recoil spectrometry (FRS) [33], also known as elastic recoil detection analysis (ERDA), is fiindamentally the same as RBS with the incident ion hitting the nucleus of one of the atoms in the sample in an elastic collision. In this case, however, the recoiling nucleus is detected, not the scattered incident ion. RBS and FRS are near-perfect complementary teclmiques, with RBS sensitive to high-Z elements, especially in the presence of low-Z elements. In contrast, FRS is sensitive to light elements and is used routinely in the detection of Ft at sensitivities not attainable with other techniques [M]- As the teclmique is also based on an incoming ion that is slowed down on its inward path and an outgoing nucleus that is slowed down in a similar fashion, depth infonuation is obtained for the elements detected. 

Elastic Recoil Detection Analysis Glow discharge mass spectrometry Glow discharge optical emission spectroscopy Ion (excited) Auger electron spectroscopy Ion beam spectrochemical analysis... 

Because the cross-sections for nuclear reaction are usually lower than the cross-sections for elastic scattering of projectiles used in RBS or in elastic recoil detection analysis (ERDA), higher currents must be used to obtain comparably high intensity in... 

The use of nuclear techniques allows the determination of C, N, H, O, and heavier contaminants relative fractions with great accuracy, and of the elements depth profile with moderate resolution (typically 10 nm). Rutherford backscattering spectroscopy (RBS) of light ions (like alpha particles) is used for the determination of carbon and heavier elements. Hydrogen contents are measured by forward scattering of protons by incident alpha particles (ERDA) elastic recoil detection analysis [44,47]. 

Diffuse reflectance infrared Fourier transform spectroscopy deuterium triglycine sulphate energy compensated atom probe energy dispersive analysis energy-loss near edge structure electron probe X-ray microanalysis elastic recoil detection analysis (see also FreS) electron spectroscopy for chemical analysis extended energy-loss fine structure field emission gun focused ion beam field ion microscope... 

This technique is known by a host of terms. As well as ERD, one sees it referred to as "forward scattering analysis, Forward Recoil Elastic Scattering (FRES) and Elastic Recoil Detection Analysis (ERDA). 

Fig. 3. Schematic of the arrangement used in elastic recoil detection (ERD) of hydrogen. Note the foil in front of the detector, used to prevent scattered beam ions from interfering with the detection of recoiling hydrogen. 

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