Fabrication of thin 140,142Ce target foils for study of nuclear reaction dynamics

We report fabrication of thin target foils of Ce-140,Ce-142 by the physical vapour deposition technique. The targets are to be used in the study of nuclear reaction dynamics with heavy ion beams. Owing to the highly reactive nature of cerium, the thin films can be oxidized during fabrication. The films were sandwiched between thin layers of C-nat to impart structural stability and prevent degradation over long periods of time. The parameters for vapour deposition were frozen after several trials with natural cerium. To obtain surface morphology, elemental composition, chemical composition and thickness of the prepared targets, those were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD) and Rutherford Back-scattering Spectroscopy (RBS). The thickness of the isotopic targets was in the range of 100-200 mu g/cm(2). XRD and RBS spectra were used to determine the stoichiometry of oxide present in the films. They were observed to be in the form of CeO2. The isotopic composition of one of the targets was determined in an in-beam experiment using a recoil mass spectrometer. Results from the experiment matched quite well with the data provided by the supplier of the isotopic material.

Automated summary

Thin target foils of Ce-140 and Ce-142 were fabricated using physical vapour deposition technique for studying nuclear reaction dynamics with heavy ion beams. The reactive nature of cerium led to oxidation of thin films during fabrication, which was addressed by sandwiching them between layers of C-nat. Characterization techniques including SEM, EDS, FTIR, XRD, and RBS were utilized to determine surface morphology, composition, and thickness of the prepared targets. The results matched well with the data provided by the isotopic material supplier.