Radium ion spectroscopy towards atomic parity violation in a single trapped ion

PhD ceremony: Mr. G.S. Giri, 16.15 uur, Aula Academiegebouw, Broerstraat 5, Groningen

Dissertation: Radium ion spectroscopy towards atomic parity violation in a single trapped ion

Promotor(s): prof. K. Jungmann

Faculty: Mathematics and Natural Sciences

An experimental set up was developed to precisely measure atomic parity violation in a single trapped radium ion and to extract the Weinberg angle in the Standard Model of particle physics at the lowest possible momentum transfer. A series of short-lived radium isotopes ^{209 - 214}Ra with nuclear spins 0, 1/2, and 5/2 was produced in fusion evaporation reactions using inverse kinematics. These isotopes were stopped and thermalized to singly charged ions in a Thermal Ionizer, mass separated in a Wien Filter, cooled and stored in a gas filled Radio Frequency Quadrupole trap. Atomic spectroscopic information such as hyperfine structure, isotope shift, and lifetime from optical precision measurements provide necessary experimental input for improving the precision of atomic structure calculation below the percent level of ac-curacy. This is indispensable for extracting the Weinberg angle. Hyperfine structure intervals of the metastable 6d ²D_3/2 states and the isotope shifts of the 6d ²D_3/2 - 7p ²P_1/2 and 6d ²D_3/2- 7p ²P_3/2 transitions were determined. A lower experimental limit for the lifetime of 232(4) ms of the metastable 6d ²D_5/2 state was established. The experimental pursuits to perform trapping and laser cooling of a single radium ion are in progress towards the precision measurement of atomic parity violation.