Towards direct mass measurements of nobelium at SHIPTRAP
Résumé
The Penning-trap mass spectrometer SHIPTRAP allows precision mass measurements of rare isotopes produced in fusion-evaporation reactions. In the first period of operation the masses of more than 50 neutron-deficient radionuclides have been measured. In this paper the perspectives for direct mass measurements of rare isotopes around nobelium are discussed and the achievable precision is addressed. The temporal stability of the magnetic field, an important issue for the long measurement times resulting from the low production rates, was investigated and the time-dependent uncertainty due to magnetic field fluctuations was determined. Based on the present performance direct mass measurements of nobelium isotopes are already feasible. With several technical improvements heavier elements between Z=102-105 will be in reach.