Preparation of actinide targets by molecular plating for coulomb excitation studies at ATLAS

Molecular plating is now routinely used to prepare sources and targets of actinide elements. Although the technique is simple and fairly reproducible, because of the radioactive nature of the targets, it is very useful to record various parameters in the preparation process. At Argonne, ∼200 μg/cm2 thick targets of Pu and Cm were required for Coulomb Excitation (COULEX) studies with the Argonne-Notre Dame boron germanate (BGO) gamma-ray facility and later with the GAMMASPHERE. These targets were plated on 50 mg/cm2 Au backings and were covered with 150 μg/cm2 Au foil. Targets of 239Pu, 240Pu, 242Pu, 244Pu and 248Cm were prepared by dissolving the material in isopropyl alcohol and electroplating the actinide ions by applying 600 V. The amount of these materials on the target was determined by alpha particle counting and gamma-ray counting. Details of the molecular plating and counting will be discussed.