Separation of actinide-made transurania by a gas-filled magnetic separator

Abstract The performance of the gas-filled magnetic separator HECK at the UNILAC at GSI Darmstadt is described. The system consists of a 30°-dipole magnet and a quadrupole doublet of wide aperture. The separator is operated with helium at pressures between 0.1–1 hPa. It is used to investigate heavy ion induced fusion products in-flight. The recoils emerging from a thin target are separated with high efficiency of 10–50%. The suppression factor of primary beam particles and transfer products is 10 15 and 10 3 , respectively. In this application of a gas-filled separator to synthesize transuranium elements using 238 U-targets, isotopes of the elements fermium and nobelium were identified in irradiations with 16 O- and 20 Ne-beams.