Mass selective laser cooling of 229Th3+ in a multisectional linear Paul trap loaded with a mixture of thorium isotopes:

We consider an experiment on trapping and laser cooling of Th-229(3+) ions in a linear Paul trap in the presence of undesirable impurities such as ions of the radioactive isotope Th-228(3+). We suggest a method of separating these impurities by means of selective laser cooling utilizing the isotope shift of cooling transitions in Th-229(3+) and Th-228(3+) ions. According to our estimation, the isotope shift is equal to 3.4 GHZ and makes laser separation of these isotopes possible.