In the present work we report an upgraded version of the radiotracer 'thin gap' ('electrode lowering') method and give a brief overview on the contribution of the secondary radiations (bremsstrahlung, characteristic X-rays, and backscattered β-particles) to the β-intensities to be detected during in-situ radiotracer sorption experiments. The results, measured by various scintillation detectors (plastic and Li-glass with thicknesses of 0.1 to 5 mm) using pure β-emitting radioisotopes of Eβmax (maximum β-energy) of 67-1710 keV, reveal that (i) at Eβmax ≥ 155 keV the contribution of the induced X-rays to the gross counting rate, irrespective of the type and thickness of the scintillation materials, is very small (less than 3.5%); (ii) at Eβmax ≤ 67 keV (e.g. 3H, 63Ni) the relative amounts of bremsstrahlung seem to be high (exceeding 15%), (iii) the intensity of backscattered β-particles is apparently dependent upon not only the average atomic number of the scatterer (adsorbent), but Eβmax of the incident β-radiation. In order to demonstrate the reliability and versatility of a version of the 'thin gap' technique illustrative examples for the in-situ radiotracer studies of various sorption phenomena (such as adsorption of bisulfate/sulfate on gold, accumulation of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) on iron, and deposition of silver on austenitic stainless steel) are also presented and discussed. Most of the implications summarized in this paper are valid for the in-situ radiotracer 'foil' method, too.
- 'Thin gap' and 'foil' methods
- Adsorption of HSO/HSO, Ag and HEDP
- In-situ radiotracer sorption studies
- Secondary β and γ
ASJC Scopus subject areas
- Analytical Chemistry
- Chemical Engineering(all)