Detection technique with single-ion sensitivity for high-precision mass measurements on superheavy elements

Mass values contribute to a number of physical models: these range from masses of exotic short-lived nuclides being important for weak interaction studies and the Standard Model of particle physics, to stable masses as means for the definition of fundamental constants [1]. Since the discovery of the superheavy elements from to , the investigations in their masses have become more and more important. They allow for tests of mass models and predictions, which deviate a lot from each other in that region. Usually, mass measurements on radionuclides with Penning traps are performed using the destructive Timeof-Flight-Ion Cyclotron Resonance (TOF-ICR) method, where the stored and with rf fields probed ions are finally ejected out of the trap. Several hundred ions are needed to get a single spectrum, which takes typically about one hour with a production rate of a few hundred ions per second and a total efficiency of about 1%. Therefore, the TOFICR technique is not applicable to rarely produced superheavy nuclides with production rates of less than one per second but rather long half-lives, sometimes even in the order of seconds or minutes. Ideally suited here is the nondestructive Fourier Transform-ICR technique, investigating the image current induced by the ions in the trap electrodes. The newly developed double-Penning trap setup for SHIPTRAP featuring both common techniques is discussed here [2].