Albedo parameter-based characterization of surface roughness in chemically etched zirconium samples

In this study, we investigate the potential of gamma-ray albedo parameters as a non-contact and radiation-based technique to characterize surface roughness variations in zirconium foils subjected to chemical etching. Zirconium samples were etched in 20 % hydrofluoric acid (HF) for different durations (30, 60, 90, and 120 s), and their surface morphology was evaluated using profilometry and gamma spectrometry. Albedo parameters were derived from the intensities of Compton and coherent scattering of 59.54 keV photons emitted by an Am-241 radioactive source, detected at a scattering angle of 168°. The results revealed a strong correlation between increasing etching time and surface roughness, as confirmed by both profilometric parameters (R_a, R_q, R_p, R_v, R_t) and albedo parameters. The rougher surfaces exhibited higher albedo parameters, indicating that photon scattering behavior is sensitive to surface topography. These findings demonstrate the feasibility of using gamma-ray scattering as an indirect probe of surface roughness, especially in environments where contact-based techniques are limited. This approach holds promise for applications in nuclear materials diagnostics, surface treatment monitoring, and biomedical implant evaluation.