Mitigation of loss within a molecular Stark decelerator

TL;DR

This paper analyzes loss mechanisms in a Stark decelerator and proposes a new quadrupole-guiding design to improve molecule retention at low velocities, enhancing deceleration efficiency.

Contribution

It identifies key loss mechanisms and introduces a novel decelerator design that reduces transverse and longitudinal coupling losses.

Findings

Modified switching sequences improve intermediate velocity stability.

The quadrupole-guiding decelerator reduces low-velocity losses.

Significant increase in stable molecules at low velocities.

Abstract

The transverse motion inside a Stark decelerator plays a large role in the total efficiency of deceleration. We differentiate between two separate regimes of molecule loss during the slowing process. The first mechanism involves distributed loss due to coupling of transverse and longitudinal motion, while the second is a result of the rapid decrease of the molecular velocity within the final few stages. In this work, we describe these effects and present means for overcoming them. Solutions based on modified switching time sequences with the existing decelerator geometry lead to a large gain of stable molecules in the intermediate velocity regime, but fail to address the loss at very low final velocities. We propose a new decelerator design, the quadrupole-guiding decelerator, which eliminates distributed loss due to transverse/longitudinal couplings throughout the slowing process and also exhibits gain over normal deceleration to the lowest velocities.