Beams of neutral polar molecules in a low-field seeking quantum state can be slowed down using a Stark decelerator, and can subsequently be loaded and confined in electrostatic quadrupole traps. The efficiency of the trap loading process is determine
d by the ability to couple the decelerated packet of molecules into the trap without loss of molecules and without heating. We discuss the inherent difficulties to obtain ideal trap loading, and describe and compare different trap loading strategies. A new split-endcap quadrupole trap design is presented that enables improved trap loading efficiencies. This is experimentally verified by comparing the trapping of OH radicals using the conventional and the new quadrupole trap designs.
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.
We present a combined experimental and theoretical study on the radiative lifetime of CO in the $a^3Pi_{1,2}, v=0$ state. CO molecules in a beam are prepared in selected rotational levels of this metastable state, Stark-decelerated and electrostatica
lly trapped. From the phosphorescence decay in the trap, the radiative lifetime is measured to be $2.63pm0.03$ ms for the $a^3Pi_1, v=0, J=1$ level. From spin-orbit coupling between the $a^3Pi$ and the $A^1Pi$ state a 20% longer radiative lifetime of 3.16 ms is calculated for this level. It is concluded that coupling to other $^1Pi$ states contributes to the observed phosphorescence rate of metastable CO.
