Scattering cross section Hydrogen

There is some disagreement in the literature as to the value of the (4He, H) elastic scattering cross section. Values differing by almost a factor of two have been reported, as reviewed by Paszti et al. (1986). The cross section is strongly non-Rutherford, but ab initio calculations have been reported that agree well with the trend of experimental data and could be used in simulation calculations (Tirira et al., 1990). The cross section for deuterium analysis has a resonance near a 4He+ energy of 2.15 MeV, which allows enhanced sensitivity. Detailed measurements of this cross section have been reported by Besenbacher et al. (1986). In practice, rather than calculate an experiment s calibration from first principles, calibration standards are usually used hydrogen-implanted silicon standard are the norm. 

FIGURE 2.13 (a) X-ray scattering factors for hydrogen, carbon, chloride and ferrous ions (b) the neutron scattering cross sections for several elements, as a function of sinOA. 

The density and thermal neutron cross-section values in Table 6 pertain to the thermal neutron attenuation gauging process. In this method, advantage is taken of the large thermal neutron scattering cross-section of hydrogen as compared to most other elements. In its simplest form, when a beam of thermal neutrons of intensity IQ traverses a sample of thickness x, the intensity 1 of neutrons measured by a thermal neutron detector will be... 

Fig. 2.18. Positron-atomic hydrogen and electron-atomic hydrogen total scattering cross sections. Experiment , positrons o, electrons both sets of data...

Fig. 3.11. Calculations of the positron-hydrogen elastic scattering cross sections ----, 18-coupled-state approximation (Kernoghan et al., 1995) (a 33-...

Positronium formation cross sections for atomic hydrogen have also been reported by Zhou et al (1997), who used the special hydrogen scattering cell described in subsection 2.5.4 with reference to their measurements of total scattering cross sections. Details were given by Zhou et al. (1997) and descriptions can be found below, since the same methods were used by the Detroit group (e.g. Zhou et al., 1994b) in their alkali metal work. 

Fig. 7.25. Compendium of positronium total scattering cross sections from Garner, Ozen and Laricchia (1998) , helium , argon , molecular hydrogen o, molecular oxygen.

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