Trapping, retention and laser cooling of Th³⁺ ions in a multisection linear quadrupole trap

A multisection linear quadrupole trap for Th³⁺ ions is described. Multiply charged ions are obtained by the laser ablation method. The possibility of trapping and retention of ∼10³ ions is demonstrated in macroscopic time scales of ∼30 s. Specific features of cooling Th³⁺ ions on the electron transitions with wavelengths of 1088, 690 and 984 nm in Th³⁺ ion are discussed; a principal scheme of a setup for laser cooling is presented. (paper)