AWhat changed
Bloch, Hänsch and Esslinger used a weak radio-frequency field to transfer atoms from a magnetically trapped rubidium condensate into an untrapped state, forming a collimated falling atomic beam. They directly imaged continuous output over up to 40 milliseconds and monitored condensate depletion over up to 100 milliseconds. Varying radio frequency also provided spatially selective spectroscopy of the trapped condensate.
Scientific scope
Bloch, Hänsch and Esslinger used a weak radio-frequency field to transfer atoms from a magnetically trapped rubidium condensate into an untrapped state, forming a collimated falling atomic beam. They directly imaged continuous output over up to 40 milliseconds and monitored condensate depletion over up to 100 milliseconds. Varying radio frequency also provided spatially selective spectroscopy of the trapped condensate. Continuous output was finite in duration and depended on a stable trap and a finite initial condensate; it was not a continuously replenished steady-state source. The 100-millisecond duration was inferred from remaining condensate counts rather than direct beam imaging over that entire interval. Beam divergence was below the imaging resolution, and brightness estimates used assumptions about velocity spreads. The spectroscopy comparison used a Thomas–Fermi approximation and displayed a broader measured response. First- and second-order coherence were not fully characterized by these measurements. Earlier pulsed atom output coupling is a separate contribution.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. Continuous output was finite in duration and depended on a stable trap and a finite initial condensate; it was not a continuously replenished steady-state source. The 100-millisecond duration was inferred from remaining condensate counts rather than direct beam imaging over that entire interval. Beam divergence was below the imaging resolution, and brightness estimates used assumptions about velocity spreads. The spectroscopy comparison used a Thomas–Fermi approximation and displayed a broader measured response. First- and second-order coherence were not fully characterized by these measurements. Earlier pulsed atom output coupling is a separate contribution.
Contributors
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Provisional WRS assessment, edition 2026-10-28.1. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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