Zeeman slower configurations. (a) Conventional wire-wound tapered solenoid; magnetic field is longitudinal, σ− light is used. denotes the current density vector. (b) Use of long tilted permanent magnets; magnetic field is transverse. Light polarisation is decomposed in its σ± components and a repumper is needed. denotes the magnetization of the material.
(a) Notations for Halbach cylinder. (b) Transverse cross section showing a 8-pole Halbach configuration.
Ideal (red/dotted) and calculated profiles, without (black/dashed) and with (blue/solid) end caps.
(a) Picture of the Zeeman slower: [M] mounts, [EC] output end cap screwed in last mount, [U] U-shaped profiles, [S] half part of the shield, [sp] 5 mm spacer between end cap and shield side. (b) Individual mount; [T] threading to screw the two parts of the mount together, [P] central square milling in which CF16 pipe goes through. (c) Detail of a square hole to show U-shaped profiles insertion, magnets [m], and plastic wedge [W]. Dimensions in mm.
Calculated (red/gray) and measured (black) magnetic field profiles. (a) Scan along the beam axis. (b) Close up of the output region. In the calculation the shield is not taken into account. Dotted and dashed lines indicate the Zeeman slower and the shield physical ends. Log scale before break.
(a) Measured magnetic field without shield across the beam axis at z ∼ 460 mm along the u-direction of Fig. 2. (b) Close up of the central region. Dashed lines indicate the atom beam extension and a 1 G magnetic field span. Line to guide the eye. Log scale before break. The shield was removed to allow the probe to go through. With the shield, the inner field is almost unaffected and the outer field is below the probe sensitivity.
Sketch of the overall experimental setup. [RO] recirculating oven, [BS] beam shutter, [CF] cold finger, [ZS] Zeeman slower, [MOT] MOT chamber, [ZB] Zeeman cycling and repumping beams, [PB] θ = 56° probe beam, and [Sh] magnetic shield. 45° and 90° probe beams are sent through the horizontal windows depicted on the MOT chamber. Dimensions in mm, not rigorously to scale.
Red/gray: thermal beam fluorescence signal. Black: absorption and fluorescence signals of the slowed beam; axis break on fluorescence signal. Inset: temperature dependence of the atom flux; line to guide the eye.
(a) Final velocity as a function of Zeeman cycling light detuning (I = 4.7 mW cm−2). Line: linear fit, the slope is 0.95 m s−1/MHz. (b) Atom flux as a function of final velocity.
(a) Atom flux as a function of cycling and repumper beams powers. (b) Cross section along the white dotted line corresponding to a total available power of 100 mW. Power ratio is measured with a scanning Fabry-Perot interferometer.
(a) Atom flux as a function of repumper frequency. Δf is the beat note frequency of the repumper with an auxiliary laser locked on the F = 2 → F′ = 3 resonance line; red/gray circles/black squares: repumper polarization perpendicular/parallel to the magnetic field. (b) Atom flux as a function of repumper power (log scale) when its frequency is fixed (black) or swept (red/gray) across the full spectrum of left panel.
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