Enhancement of the ${}^{81}\mathrm{Kr}$ and ${}^{85}\mathrm{Kr}$ count rates by optical pumping

Abstract

We report an increase of up to 60% on the count rates of the rare ${}^{81}\mathrm{Kr}$ and ${}^{85}\mathrm{Kr}$ isotopes in the Atom Trap Trace Analysis method by enhancing the production of metastable atoms in the discharge source. Additional atoms in the metastable $1s_5$ level (Paschen notation) are obtained via optically pumping the $1s_4-2p_6$ transition at 819 nm. By solving the master equation for the system, we identify this transition to be the most suitable one and can describe the measured increase in metastable population as a function of the 819-nm laser power. We calculate the previously unknown isotope shifts and hyperfine splittings of the $1s_4-2p_6$ transition in ${}^{81}\mathrm{Kr}$ and ${}^{85}\mathrm{Kr}$, and verify the results with count rate measurements. The demonstrated count-rate increase enables a corresponding decrease in the required sample sizes for ${}^{81}\mathrm{Kr}$ and ${}^{85}\mathrm{Kr}$ dating, a significant improvement for applications such as dating of ocean water and deep ice cores.

References in corpus (6)

• ${}^{81}$Kr dating at the Guliya ice cap, Tibetan Plateau
• Microcontroller based scanning transfer cavity lock for long-term laser frequency stabilization
• A Thermal Beam of Metastable Krypton Atoms Produced by Optical Excitation
• A novel vacuum ultra violet lamp for metastable rare gas experiments
• Optically enhanced production of metastable xenon
• All-optical production and trapping of metastable noble gas atoms down to the single atom regime

Cited by in corpus (3)

• Optical Excitation and Trapping of ${}^{81}$Kr
• Maximizing optical production of metastable xenon
• Optically enhanced discharge excitation and trapping of ${}^{39}Ar$