Stark deceleration of NO radicals

TL;DR

This paper demonstrates the successful Stark deceleration of NO radicals, a chemically important species with a small dipole moment, by preparing specific quantum states and using a long Stark decelerator to significantly reduce their velocity.

Contribution

It is the first to achieve Stark deceleration of NO radicals by exploiting a higher effective dipole moment in a specific quantum state and employing a 316-stage decelerator.

Findings

Decelerated NO radicals from 315.0 m/s to 229.2 m/s.

Removed 47% of the radicals' kinetic energy.

Experimental results agree with numerical simulations.

Abstract

We report on the Stark deceleration of a pulsed molecular beam of NO radicals. Stark deceleration of this chemically important species has long been considered unfeasible due to its small electric dipole moment of 0.16 D. We prepared the NO radicals in the X 2{\Pi}3/2, v=0, J=3/2 spin-orbit excited state from the X 2{\Pi}1/2, v=0, J=1/2 ground state by Franck-Condon pumping via the A 2{\Sigma}+ state. The larger effective dipole moment in the J=3/2 level of the X 2{\Pi}3/2, v=0 state, in combination with a 316-stages-long Stark decelerator, allowed us to decelerate NO radicals from 315.0 m/s to 229.2 m/s, thus removing 47 % of their kinetic energy. The measured time-of-flight profiles of the NO radicals exiting the decelerator show good agreement with the outcome of numerical trajectory simulations.