Principles and design of a Zeeman-Sisyphus decelerator for molecular beams

TL;DR

This paper introduces a static magnetic field and optical pumping-based Zeeman-Sisyphus decelerator for molecular beams, capable of decelerating and guiding molecules like CaF in a time-independent manner.

Contribution

It presents a novel, practical design for a Zeeman-Sisyphus decelerator that can be used for both pulsed and continuous molecular beams, with detailed simulations and performance comparisons.

Findings

Decelerates CaF molecular beams effectively

Allows simultaneous guiding and deceleration

Compresses velocity distribution during deceleration

Abstract

We explore a technique for decelerating molecules using a static magnetic field and optical pumping. Molecules travel through a spatially varying magnetic field and are repeatedly pumped into a weak-field seeking state as they move towards each strong field region, and into a strong-field seeking state as they move towards weak field. The method is time-independent and so is suitable for decelerating both pulsed and continuous molecular beams. By using guiding magnets at each weak field region, the beam can be simultaneously guided and decelerated. By tapering the magnetic field strength in the strong field regions, and exploiting the Doppler shift, the velocity distribution can be compressed during deceleration. We develop the principles of this deceleration technique, provide a realistic design, use numerical simulations to evaluate its performance for a beam of CaF, and compare this performance to other deceleration methods.