Polarization-dependent spectra in the photoassociative ionization of cold atoms in a bright sodium beam

Ramirez-Serrano, Jaime; DeGraffenreid, W.; Weiner, J.

doi:10.1103/physreva.65.052719

Cited by 7 publications

(11 citation statements)

References 12 publications

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“…This is not unexpected, as the loss rate due to trapped atoms being extracted into the CAB dominates over all other loss mechanisms within the pyramidal MOT, and the densities within the atomic beam (Ͻ2 ϫ 10 7 atom/cm 3 ) are still an order of magnitude too low for these cold collisions to be observed. 16,21,22 The effect of heteronuclear cold collisions is readily apparent within the mixed-species UHV MOT, however. We observe decreased trap lifetimes for the Cs MOT in the presence of simultaneously trapped Rb, and vice versa.…”

Section: Studying Heteronuclear Cold Collisions With the Two-species mentioning

confidence: 99%

Two-species cold atomic beam

et al. 2004

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We generate a bright atomic beam containing laser-cooled rubidium and cesium, and we use this beam to load a mixed-species ultrahigh-vacuum (UHV) magneto-optical trap. We have characterized our two-species atomic beam over a range of operating conditions, and we obtain similar atom fluxes for each species. Within the UHV trap, interspecies inelastic collisions are observed in the form of enhanced decay rates of a given species in the presence of a second trapped species. We analyze the trap decays to obtain a loss rate due to heteronuclear cold collisions, and we compare our result to similar measurements in vapor-cell traps [Phys. Rev. A 63, 033406 (2001)].

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Section: Studying Heteronuclear Cold Collisions With the Two-species mentioning

confidence: 99%

Two-species cold atomic beam

et al. 2004

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“…Although this simple model indeed explains the overall factor of 4, it does not predict the dependence observed for other linear polarizations. A more detailed model would be necessary to fully explain the behavior of K with respect to the polarization angle in intermediate cases, but similar results were obtained in experiments using a decelerated atomic beam of sodium [12].…”

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confidence: 54%

Photoassociative ionization of Na inside a storage ring

Paiva

Riaz

Shiozaki

et al. 2012

Optics Communications

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Motivated by recent interest in low dimensional arrays of atoms, we experimentally investigated the way cold collisional processes are affected by the geometry of the considered atomic sample. More specifically, we studied the case of photoassociative ionization (PAI) both in a storage ring where collision is more unidirectional in character and in a trap with clear undefinition of collision axis. First, creating a ring shaped trap (atomotron) we investigated two-color PAI dependence with intensity and polarization of a probing laser. The intensity dependence of the PAI rate was also measured in a magneto-optical trap presenting equivalent temperature and density conditions. Indeed, the results show that in the ring trap, the value of the PAI rate constant is much lower and does not show evidences of saturation, unlike in the case of the 3D-MOT. Cold atomic collisions in storage ring may represent new possibilities for study.© 2012 Elsevier B.V. All rights reserved.The field of cold atomic collisions followed the overall development of cold atomic physics in general [1]. The area gave rise to an exciting collection of scientific opportunities and still provides steam for future achievements. Study of novel cold collision geometries may contribute to a better understanding of reaction dynamics, possibly pushing back the frontiers of quantum chemistry.One of the many questions that motivated the investigation of cold collisions is how an optical field can modify the outcome of a collisional encounter. A natural environment for observation of such an effect is an atomic trap, like the magneto-optical trap (MOT) for instance. In such a system there is no preferable axis of collision and only average effects can be measured. Experiments involving atomic beams decelerated by radiation pressure, yet are alternatives to this situation [2]. However, for collisions in the sub-millikelvin temperature regime, the atomic beam density is usually much below the one you can reach in a MOT. Recently though, our research group has advised a new way to study cold collisions, producing a ring shaped trap (atomotron) [3], where atomic encounters preferably take place along one single direction. This trap actually works close to a continuous atomic beam of cold atoms with the tangential direction as the preferable collisional axis.Concerning cold collision processes, Photoassociative Ionization (PAI) [4] probably figures amongst the most important ones. PAI is a two step molecular formation resulting in an ionized dimer. PAI was the first measured collisional process observed between cooled atoms [5] and even though it already has been intensively explored [1], open questions still remain, specially related to the relative reaction rates measured in traps and in atomic beams. Due to technical difficulties, temperatures in both systems were never compatible and a fair comparison was never performed for sodium.Conventional associative ionization proceeds in two steps: excitation of isolated atoms followed by molecular autoionization wh...

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“…Ramirez-Serrano et al 49 used a cold, bright sodium beam to study PAI in intra-beam collisions at a collision temperature of 4 mK. They recorded the one-color PAI rate as a function of red detuning from 0 to 45 GHz and as a function of the laser polarization alignment, parallel or perpendicular to the atom beam.…”

Section: Photoassociative Ionization In Atom Beamsmentioning

confidence: 99%

“…In cell and trap experiments it is usually a Maxwell-Boltzmann distribution at some well-defined temperature, but f (v) in atomic beam experiments, arising from optical excitation velocity selection, deviates radically from the normal thermal distribution. [47][48][49] The actual signal count rate,…”

Section: Associative and Photoassociative Ionizationmentioning

confidence: 99%