Chemical conversions in lead thin films induced by heavy-ion beams at Coulomb barrier energies

Meyer C-C, Dragoun A, Düllmann Ch E, Haas R, Jäger E, Kindler B, Lommel B, Prosvetov A, Rapps M, Renisch D, Simon P, Tomut M, Trautmann C, Yakushev A

Abstract

Superheavy elements are produced via fusion reactions, by bombarding thin target foils with intense beams of energetic ions with energies around the Coulomb barrier. Currently, production of rare isotopes relies mainly on the molecular plating (MP) method, which yields thin films of the desired target material on a backing foil. Intense heavy-ion beams are known to modify the film structure, which leads to deterioration of the targets over irradiation time. To gain a better understanding of the processes at a microsopic scale, comparative tests were carried out using Coulomb barrier heavy-ion beams provided from the UNILAC accelerator at GSI Darmstadt, Germany. For this purpose, targets of lead were prepared using MP and Drop-on-Demand inkjet-printing. Lead targets were baked-in and analysed by digital optical microscopy, scanning electron microscopy and confocal Raman spectroscopy.