Getting the elastic scattering length by observing inelastic collisions in ultracold metastable helium atoms

Abstract

We report an experiment measuring simultaneously the temperatureand the flux of ions produced by a cloud of triplet metastablehelium atoms at the Bose-Einstein critical temperature. The onsetof condensation is revealed by a sharp increase of the ion fluxduring evaporative cooling. Combining our measurements withprevious measurements of ionization in a pure BEC,we extract an improved value of the scattering length$a=11.3_{-1}^{+2}$ nm. The analysis includes corrections takinginto accountthe effect of atomic interactions on the criticaltemperature, and thus an independent measurement of the scatteringlength would allow a new test of these calculations.

References in corpus (13)

• Theory of Bose-Einstein condensation in trapped gases
• Bose-Einstein Condensation of Metastable Helium
• Condensate fraction and critical temperature of a trapped interacting Bose gas
• Three-body recombination of ultra-cold atoms to a weakly bound $s$ level
• Three-body recombination in Bose gases with large scattering length
• The critical temperature of a trapped, weakly interacting Bose gas
• Dynamics of a classical gas including dissipative and mean field effects
• T_c for trapped dilute Bose gases: a second-order result
• Ultracold collisions of metastable helium atoms
• Bose-Einstein transition temperature in a dilute repulsive gas
• Collisional relaxation in diffuse clouds of trapped bosons
• Ionization rates in a Bose-Einstein condensate of metastable Helium
• Theory of evaporative cooling with energy-dependent elastic scattering cross section and application to metastable helium

Cited by in corpus (13)

• Correlations and Counting Statistics of an Atom Laser
• Cold and trapped metastable noble gases
• A Degenerate Bose-Fermi Mixture of Metastable Atoms
• Accurate determination of the scattering length of metastable Helium atoms using dark resonances between atoms and exotic molecules
• Hybrid apparatus for Bose-Einstein condensation and cavity quantum electrodynamics: Single atom detection in quantum degenerate gases
• Frequency shifts of photoassociative spectra of ultracold metastable Helium atoms : a new measurement of the s-wave scattering length
• Collisional Properties of Cold Spin-Polarized Metastable Neon Atoms
• Homonuclear ionizing collisions of laser-cooled metastable helium atoms
• Magnetic-field dependent trap loss of ultracold metastable helium
• Prospects for measurement and control of the scattering length of metastable helium using photoassociation techniques
• Direct Measurement of the Forbidden $2^3{S}_1\to 3^3{S}_1$ Atomic Transition in Helium
• Rotationally induced Penning ionization of ultracold photoassociated helium dimers
• Scattering length determination from trapped pairs of atoms