Loading of mass spectrometry ion trap with Th ions by laser ablation for nuclear frequency standard application.

We describe an original multisectional quadrupole ion trap aimed to realize nuclear frequency standard based on the unique isomer transition in thorium nucleus. It is shown that the system effectively operates on Th, Th and Th ions produced by laser ablation of metallic thorium-232 target. Laser intensity used for ablation is about 6 GW/cm.

Mass selective laser cooling of Th in a multisectional linear Paul trap loaded with a mixture of thorium isotopes.

We consider an experiment on trapping and laser cooling of Th ions in a linear Paul trap in the presence of undesirable impurities such as ions of the radioactive isotope Th. We suggest a method of separating these impurities by means of selective laser cooling utilizing the isotope shift of cooling transitions in Th and Th ions. According to our estimation, the isotope shift is equal to 3.