Detection of hydrogen by electron Rutherford backscattering

Abstract

A novel method for detection of hydrogen by an electron beam in extremely thin samples is described. Elastically scattered electrons impinging with 20-30 keV on a thin formvar film were detected at a scattering angle near 451: In these large momentum transfer elastic collisions a clear separation of the signal of hydrogen and heavier elements was found. By changing the momentum transfer we can verify that the hydrogen signal is not due to inelastic energy loss contributions. The width of the hydrogen elastic peak is much larger than the elastic peaks due to heavy elements (carbon and oxygen). The ratio of the hydrogen elastic peak and the main elastic peak is smaller than expected by 30-50% depending on the energy of the impinging electron. This could be due to electronic excitations directly coupled to the elastic collision. The stability of the formvar film under electron radiation was studied. A reduction in thickness of the film with increasing fluence, as well as the preferential depletion of hydrogen, was found. Possible improvements of the experimental configuration for this type of experiments are discussed. r

Site-Specific Recoil Diffraction of Backscattered Electrons in Crystals

“…This will greatly enhance the potential of SEM methods for phase identification in materials science. For instance, as hydrogen atoms are well resolved in ERBS [25], our results suggest a new electron-spectroscopic method, sensitive to the position of hydrogen in crystals [26].…”

Comparison of Electron and Neutron Compton Scattering from Entangled Protons in a Solid Polymer

“…The associated systematic and statistical errors of the ECS results (including the uncertainty of the baseline of the H peak) are estimated to be about 10%. For the ECS experiment, it was checked that no radiation induced modifications of the film occurred for doses required to obtain good quality spectra [23]. Considerable efforts to identify various possible sources of NCS-experimental errors have been made; see, e.g., Refs.…”

The Potential of Materials Analysis by Electron Rutherford Backscattering as Illustrated by a Case Study of Mouse Bones and Related Compounds

“…Encouraged by the good results for CaCO 3 we now proceed with hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ), on which again ≈1 Å of Au was evaporated. In principle, ERBS can detect hydrogen as well (Vos, 2002; Yubero et al, 2005; Yubero & Tökèsi, 2009), but because of its low concentration in hydroxyapatite, low cross-section (see Table 1), and presumably large peak width, hydrogen detection is not realistic in the present case, and the measured spectra was restricted to the low energy-loss region.…”