Preparation of selenium target using sedimentation method for in-beam γ-ray spectroscopic measurement

Abstract

Natural and isotopically enriched selenium targets with a typical thickness of 6.8 mg/cm${}^2$ were prepared using only 20 mg of powder, which was deposited on a Mylar backing through sedimentation process. The surface morphology of these targets was examined using scanning electron microscopy, while elemental analysis was conducted through $X$-ray photoelectron spectroscopy, energy-dispersive $X$-ray spectroscopy and $X$-ray diffraction technique. These analyses confirmed that the selenium retained its crystalline structure, with no elemental impurities other than carbon and oxygen. The presence of carbon and oxygen was mainly due to the polyvinyl alcohol used during fabrication. The thickness of the targets was measured via $X$-ray attenuation using a Germanium-based Low-Energy Photon Spectrometer. These targets were subsequently employed in ion-beam-induced $\gamma$-ray spectroscopic measurements to investigate the nuclear level structure of ${}^{81,82}$Br. Even after five days of continuous beam exposure, the condition of the targets remained unchanged. X-ray diffraction analysis of the irradiated targets showed no significant changes in microstrain and crystallite size.