Interaction between metastable krypton atoms in the 3 P 2 state

Nikolay A. Kryukov, P. A. Savel'Ev, M. A. Chaplygin

Xiao Jiang Pan

L. Dana, Pierre Laures

Nikolay A. Kryukov, N. P. Penkin, T. P. Reďko

M. A. Dakka, Georgios Tsiminis, R. D. Glover +6 more

We demonstrate the generation of metastable krypton in the long-lived 1s^{5} state using laser excitation. The atoms are excited through a two-photon absorption process into the 2p^{6} state using a pulsed optical parametric oscillator laser operating near 215 nm, after which the atoms decay quickly into the metastable state with a branching ratio of 75%. The interaction dynamics are modeled using density matrix formalism and, by combining this with experimental observations, we are able to calculate photoionization and two-photon absorption cross sections. When compared to traditional approaches to metastable production, this approach shows great potential for high-density metastable krypton production with minimal heating of the sample. Here, we show metastable production efficiencies of up to 2% per pulse. The new experimental results gained here, when combined with the density matrix model we have developed, suggest that fractional efficiencies up to 30% are possible under optimal conditions.

V. Lefèvre-Seguin, Michèle Leduc

Collisions between rare-gas atoms in the 3 P 2 metastable state and in the ground state were studied. The metastable atoms were created by a discharge and oriented by optical pumping, and pressure broadening of their magnetic-resonance curves was measured. For xenon, mixtures of even and odd isotopes were used, leading to a determination of the cross section for metastability-exchange collisions. For krypton the results are reported for the disorientation of the metastable state in the natural gas. In addition the disorientation cross section has been measured of the krypton metastable state through collisions with helium.