Ions and atoms in superfluid helium (4He)

An improved ion source based on laser ablation was developed which allows to implant a great variety of impurity ions into liquid helium (4He). This ion source can be operated in the gas phase as well as inside the liquid helium opening up the opportunity to use pressurized liquid helium for the mobility studies also. Low field mobilities have been remeasured for He+, Ca+, Sr+ and Ba+ ions and measured for the so far unknown case of Mg+. The data for the ions investigated previously agree well with former measurements at similar temperatures. The mobility data for the Mg+ ion fit well into the trend extrapolated from the other ions.