Precision Spectroscopyof the 9s and 8p levels

of Francium.

by Seth Aubin

Graduate Students:Eduardo GomezKerim GulyuzJerry Sell

Professors:Luis A. OrozcoGene D. Sprouse

Work supported by NSF

Universityof

Toronto

Precision Spectroscopy in Francium

Objective:

Spectroscopy probes electronic wavefunctions

• Lifetime wavefunctions far from nucleus

• Hyperfine splitting wavefunction near nucleus

Importance:

Francium is the heaviest alkali (Z=87).

Test of wavefunctions in relativistic regime.

Parity non-conservation experiments.

Excitation of the 9s level of 210Fr

E1 decay channels of the 9s and 8p levels

Lifetime Measurements:

Time-correlated Single-photon Counting

~10,000210Fr atoms

9s lifetime data and fit

Results for 9S1/2 Lifetime Error %Statistical ± 0.72TAC/MCA performance < ± 0.04Displacement error from Rb < ± 0.38Quantum beats < ± 0.20Total ± 0.84 %

Opt. Lett. 28, 2055 (2003)

8p lifetimes

Results for 8P3/2 Lifetime Error %Statistical ± 1.05Bayesian (9S1/2) ± 1.44TAC/MCA performance < ± 0.30Contamination shift error ± 0.03Total ± 1.8 %

Results for 8P1/2 Lifetime Error %Statistical ± 2.3Bayesian ± 0.4TAC/MCA performance < ± 0.2Total ± 2.3 %

Hyperfine Splitting (HFS)

Scan probe laser across F=11/2 and F=13/2 hyperfine levels of the 9S1/2 level.

Record fluorescence vs. frequency

Method:

With wavemeter: HFS = 4045.2 1.5 MHz (statistical)

SUMMARY

Measurements of the 9S1/2 lifetime and HFS.

Measurements of the 8P3/2 and 8P1/2 lifetimes.

Theoretical predictions agree with lifetime measurements.

Future: use HFS to extract nuclear g-factor for 210Fr.