A Zeeman slower design with permanent magnets in a Halbach configuration

Abstract

We describe a simple Zeeman slower design using permanent magnets. Contrary to common wire-wound setups no electric power and water cooling are required. In addition, the whole system can be assembled and disassembled at will. The magnetic field is however transverse to the atomic motion and an extra repumper laser is necessary. A Halbach configuration of the magnets produces a high quality magnetic field and no further adjustment is needed. After optimization of the laser parameters, the apparatus produces an intense beam of slow and cold 87 Rb atoms. With typical fluxes of 1 to 5 × 10 10 atoms/s at 30 m · s −1 , our apparatus efficiently loads a large magneto-optical trap with more than 10 10 atoms in one second, which is an ideal starting point for degenerate quantum gases experiments.

A versatile dual-species Zeeman slower for caesium and ytterbium

“…In row (viii) we give the associated magnetic field span |B L | and we see that it is generally of order a few hundred gauss, hence large coils with hundreds of amp-turns are usually constructed. Alternative schemes have been successfully demonstrated, e.g., deploying arrays of permanent magnets 46,[59][60][61] or a single winding with a variable pitch. 62 For Li and Na the required field span becomes rather large which stems ultimately from their small mass and associated large oven e↵usion speed.…”

Detailed study of a transverse field Zeeman slower

“…Our Zeeman slower design follows the same architecture than the one described in [12] adapting its shape to fit sodium atoms specifici-ties. As in [12], we work with an increasing magnetic field configuration. As a result, the laser beam addresses the |F = 2, m F = −2 to |F = 3, m F = −3 transition, where F and F represent respectively the total angular momentum of the ground and excited states and m F and m F their projections onto the quantization axis.…”

“…3 (b) and (d)). Since the shape of the ideal magnetic field profile is quite steep toward the end, an additional ring made of 10 mm-side cubic magnets of N35 grade (B R = 11.7 kG) is added at the end of the structure [12]. In order to adjust the geometry of the Zeeman slower shown in Fig.…”

Compact bulk-machined electromagnets for quantum gas experiments

“…After cleaning and drying, the spiral was impregnated with epoxy glue. We used commercial low viscosity, room-temperature curing epoxy 3 , loaded with 10% of 0.25 µm fiber glass flake and 30% aluminium nitride (AlN) powder 4 . Preliminary tests showed that cracks can develop in the inter-windings regions due to thermal stress when using high temperature curing expoxy, hence the use of a fiber glass load to reinforce the structure.…”

“…As experimental apparatus become more and more complex, with more laser beams or high-aperture imaging systems to accommodate, space occupation as well as heat management constraints become more and more acute, calling for optimized and flexible electromagnet designs. Efforts in this direction have been reported in the past years, in particular novel designs for Zeeman slowers [3,4], Bitter electromagnets [5][6][7] or improved heat management methods [8]. More compact systems of magnetic traps use in-vacuum electromagnets [9][10][11], or atom chips [12,13], but those are not adapted to experiments requiring large homogeneous fields.…”