title: Principles and Design of a Zeeman-Sisyphus Decelerator for Molecular Beams.
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.
authors.affiliation: Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: N J
authors.identifier: http://orcid.org/0000-0003-3956-8456
authors.initials: NJ
authors.lastname: Fitch
authors.affiliation: Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK.
authors.forename: M R
authors.identifier: http://orcid.org/0000-0003-2713-9531
authors.initials: MR
authors.lastname: Tarbutt
keywords: buffer-gas beams; cold molecules; laser cooling molecules; molecular beam deceleration; optical pumping