A. M. Ionan

Combined target-ion source unit for production of rare nuclides

A combined target-ion source unit (ionizing target) has been developed for the on-line production of radioactive single-charged ions. The target is able to withstand temperatures of up to 2500 °C and also acts as an ion source of surface, electron-beam, and laser ionizations. Using tantalum foil as a target material, the on-line combined target-ion source unit efficiency, which is the product of the ionization and release efficiencies, has been obtained for neutron-deficient isotopes of Eu, Gd, and Yb. These nuclides were ionized by the surface ionization inside a hot tungsten target container, holding tantalum foils as a target material. The results of the combined target-ion source unit use for on-line laser resonant ionization spectroscopy investigation of neutron-deficient Gd isotopes have been also presented. For neutron-rich isotopes produced from a high-density UC target, which were ionized by the surface ionization inside the target container, the ionization efficiency values have been obtained close to 100% for Rb and Cs and 10% for In. For Ag and Sn neutron-richisotopes, the values of the electron-beam ionization efficiency in the volume of the targetcontainer, correspondingly equal to 4% and 2%, have been obtained.

Enhancement of ionization efficiency of surface, electron bombardment and laser ion sources by axial magnetic field application

Effect of an axial magnetic field influence on the ionization efficiency of surface and laser ion sources has been observed. The axial magnetic field applying in the range 500–800 G gives an increase of the ion current of atoms of all elements those are ionized in a hot cavity of the surface or laser ion source. Moreover, if for ionization of atoms with low ionization potentials such as K, Rb, and Cs the magnetic field applying effect is negligible, for elements with ionization potentials higher than 6 eV, such as Gd, Tm, Yb, Lu, and others it reaches value about 20 in the ion source temperature region of 2100–2500 °C. The results of on-line experiments are presented confirming the influence of the axial magnetic field on the ionization efficiency rise of neutron-deficient isotopes of rare-earth elements produced in the combined ion source-target assembly (ionizing target) and Eu isotopes resonantly ionized in the laser ion source and in the high temperature ionizing target.