Velocity-selected molecular pulses produced by an electric guide

TL;DR

This paper presents a method to produce tunable, narrow-velocity molecular pulses using an electric guide, enabling controlled delivery of slow polar molecules for various applications.

Contribution

The authors extend electrostatic velocity filtering to generate velocity-tunable pulses with narrow spreads, demonstrated with ND3 molecules, supported by Monte-Carlo simulations.

Findings

Pulses with velocities of 20-100 m/s were produced.

Pulses contained up to 10^6 molecules at 60 m/s.

The technique achieves a relative velocity spread of 16%.

Abstract

Electrostatic velocity filtering is a technique for the production of continuous guided beams of slow polar molecules from a thermal gas. We extended this technique to produce pulses of slow molecules with a narrow velocity distribution around a tunable velocity. The pulses are generated by sequentially switching the voltages on adjacent segments of an electric quadrupole guide synchronously with the molecules propagating at the desired velocity. This technique is demonstrated for deuterated ammonia (ND$_{3}$), delivering pulses with a velocity in the range of $20-100\,\rm{m/s}$ and a relative velocity spread of $(16\pm 2)\,%$ at FWHM. At velocities around $60\,\rm{m/s}$, the pulses contain up to $10^6$ molecules each. The data are well reproduced by Monte-Carlo simulations, which provide useful insight into the mechanisms of velocity selection.