arXiv subjects

Markus Metsala

Publications and source records attributed to Markus Metsala.

3 recordsLinked to original sources

arXiv2008

Reflection of OH molecules from magnetic mirrors

We have reflected a Stark-decelerated beam of OH molecules under normal incidence from mirrors consisting of permanent magnets. Two different types of magnetic mirrors have been demonstrated. A long-range flat mirror made from a large disc magnet has been used to spatially focus the reflected beam in the longitudinal direction ("bunching"). A short-range curved mirror composed of an array of small cube magnets allows for transverse focusing of the reflected beam.

physics.chem-ph↗

arXiv2008

The radiative lifetime of metastable CO ($a^3Π, v=0$)

We present a combined experimental and theoretical study on the radiative lifetime of CO in the $a^3Π_{1,2}, v=0$ state. CO molecules in a beam are prepared in selected rotational levels of this metastable state, Stark-decelerated and electrostatically trapped. From the phosphorescence decay in the trap, the radiative lifetime is measured to be $2.63\pm0.03$ ms for the $a^3Π_1, v=0, J=1$ level. From spin-orbit coupling between the $a^3Π$ and the $A^1Π$ state a 20% longer radiative lifetime of 3.16 ms is calculated for this level. It is concluded that coupling to other $^1Π$ states contributes to the observed phosphorescence rate of metastable CO.

physics.atom-ph↗

arXiv2008

Electrostatic trapping of metastable NH molecules

We report on the Stark deceleration and electrostatic trapping of $^{14}$NH ($a ^1Δ$) radicals. In the trap, the molecules are excited on the spin-forbidden $A ^3Π\leftarrow a ^1Δ$ transition and detected via their subsequent fluorescence to the $X ^3Σ^-$ ground state. The 1/e trapping time is 1.4 $\pm$ 0.1 s, from which a lower limit of 2.7 s for the radiative lifetime of the $a ^1Δ, v=0,J=2$ state is deduced. The spectral profile of the molecules in the trapping field is measured to probe their spatial distribution. Electrostatic trapping of metastable NH followed by optical pumping of the trapped molecules to the electronic ground state is an important step towards accumulation of these radicals in a magnetic trap.

physics.atom-ph↗