Fabrication and characterization of thin 64Zn and 68Zn targets for nuclear reaction measurements

Abstract

Isotopically enriched targets of 64,68Zn were prepared for heavy ion fusion and multi-nucleon transfer reactions. In view of the fragility of the targets under the ion current and during characterization, multiple targets of each isotope were required. Thin films of 64,68Zn isotopes were fabricated via vapor deposition in the target laboratory at Inter-University Accelerator Center (IUAC), New Delhi. Multiple targets of 64,68Zn in the thickness range 150 μg/cm2–300 μg/cm2, were synthesized on a carbon backing of 10 μg/cm2 using only 30 mg amount of available enriched material for each isotope. The use of a pin source and carbon foils as substrate allowed the fabrication of Zn targets without employing previously suggested methods of substrate cooling and forced condensation for thin film fabrication of volatile elements. The deposition results have been estimated quantitatively. The thickness measurement of the targets was carried out using the α particle energy loss technique and Rutherford Back Scattering (RBS) method. The elemental composition of the targets was examined using RBS and Dispersive Wavelength X-ray Fluorescence (DWXRF) to investigate the contamination. Morphological analysis of the films was performed using Scanning Electron Microscope (SEM) to study homogeneity and the impact of ion bombardment on the targets.