Beam characterizations of mass separated, low-energy positive and negative ions deposition apparatus

The authors study properties of positive and negative ion beams mainly focused on the characterizations of the ion beam energy on a newly developed apparatus for isotopically mass separated, low-energy, positive and negative ions deposition. In the positive ion beam line, a plasma potential inside the ion source was about 50 to 100 V, depending on a gas pressure, a magnetron power and an applied magnetic field. It decreased with the increasing gas pressure and with decreasing the microwave power and the magnetic field. The energy spread (full width at half maximum) was about 8-10 eV almost independent of various parameters, for example, the gas pressure, ion species, etc. The fluctuation of the beam energy was about a few eV during ten hours.