Measurement of low-energy total absolute atomic collision cross sections with the metastable<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi>P</mml:mi><mml:mn>2</mml:mn><mml:none /><mml:mprescripts /><mml:none /><mml:mn>3</mml:mn></mml:mmultiscripts></mml:math>state of neon using a magneto-optical trap

Matherson, Kristen; Glover, Rohan David; Laban, Dane Edward; Sang, R. T.

doi:10.1103/physreva.78.042712

Cited by 21 publications

(23 citation statements)

References 29 publications

(43 reference statements)

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“…Also, collisional loss rates at a known background gas density and MOT trap depth have been used to characterize collision cross sections [9][10][11], or alternatively collision rates at a known cross section and gas density can be used to characterize the MOT trap depth [12].…”

Section: Introductionmentioning

confidence: 99%

Vacuum-pressure measurement using a magneto-optical trap

Arpornthip¹,

Sackett²,

Hughes³

2012

Phys. Rev. A

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The loading dynamics of an alkali-metal-atom magneto-optical trap can be used as a reliable measure of vacuum pressure, with loading time τ indicating a pressure less than or equal to (2 × 10 −8 Torr s)/τ . This relation is accurate to approximately a factor of 2 over wide variations in trap parameters, background gas composition, or trapped alkali-metal species. The low-pressure limit of the method does depend on the trap parameters, but typically extends to below 1 × 10 −9 Torr.

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Section: Introductionmentioning

confidence: 99%

Vacuum-pressure measurement using a magneto-optical trap

Arpornthip¹,

Sackett²,

Hughes³

2012

Phys. Rev. A

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“…Recently, laser cooling and trapping of metastable rare-gas atoms in magnetooptical traps (MOT) [78][79][80][81] and the achievement of Bose-Einstein condensation (BEC) in spin-polarized He (2 3 S) gas [82,83] has led to renewed interest in collisions of excited rare-gas atoms with photons [84], electrons [85], atoms [86][87][88][89], and molecules [90].…”

Section: Introductionmentioning

confidence: 99%

Photoionization dynamics of excited Ne, Ar, Kr and Xe atoms near threshold

Sukhorukov¹,

Petrov²,

Schäfer³

et al. 2012

J. Phys. B: At. Mol. Opt. Phys.

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A review of experimental and theoretical studies of the threshold photoionization of the heavier rare-gas atoms is presented, with particular emphasis on the autoionization resonances in the spectral region between the lowest two ionization thresholds (mp 5 2 P 3/2 and mp 5 2 P 1/2 , with m = 2, 3, 4, and 5 for Ne, Ar, Kr, and Xe, respectively). Observed trends in the positions, widths, and shapes of the autoionization resonances in dependence of the atomic number, the principal quantum number n, the orbital angular momentum quantum number and further quantum numbers such as K, J and F specifying the fine-and hyperfine-structure levels, are summarized and discussed in the light of ab initio and multichannel quantum defect theory calculations. The dependence of the photoionization spectra on the initially prepared neutral state, e.g. the 1 S 0 ground state, the mp 5 (m + 1)s 3 P 2 and mp 5 (m + 1)s 3 P 0 metastable levels and other states prepared from the ground or metastable levels in single-and multiphoton processes, are also discussed, including results on the photoionization of aligned and oriented samples and on photoelectron angular distributions. The effects of various approximations in the theoretical treatment of photoionization in these systems are analysed. The very large and at first sight discouraging diversity of observed phenomena and the numerous anomalies in spectral structures associated with the threshold ionization of the rare-gas atoms can be described in terms of a limited set of interactions and dynamical processes. Examples are provided illustrating characteristic aspects of the photoionization, and sets of recommended parameters describing the energy-level structure and photoionization dynamics of the rare-gas atoms are presented which were extracted in a critical analysis of the very large body of experimental and theoretical data available on these systems in the literature.

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“…These measurements involve collisions of trapped neutral particles with neutral atoms and molecules [20][21][22][23][24], electron beams [25][26][27], and trapped ions [28][29][30]. Photoionization cross sections have also been investigated though measurements of trap loss rates [31][32][33].…”

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confidence: 99%

Trap-depth determination from residual gas collisions

et al. 2011

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We present a method for determining the depth of an atomic or molecular trap of any type. This method relies on a measurement of the trap loss rate induced by collisions with background gas particles. Given a fixed gas composition, the loss rate uniquely determines the trap depth. Because of the "soft" long-range nature of the van der Waals interaction, these collisions transfer kinetic energy to trapped particles across a broad range of energy scales, from room temperature to the microkelvin energy scale. The resulting loss rate therefore exhibits a significant variation over an enormous range of trap depths, making this technique a powerful diagnostic with a large dynamic range. We present trap depth measurements of a Rb magneto-optical trap using this method and a different technique that relies on measurements of loss rates during optical excitation of colliding atoms to a repulsive molecular state. The main advantage of the method presented here is its large dynamic range and applicability to traps of any type requiring only knowledge of the background gas density and the interaction potential between the trapped and background gas particles.The particle loss rate from a trap is one of the primary observables for probing the collisional physics of trapped gases. Measurements of trap loss are routinely made in a variety of experiments to deduce elastic and inelastic collision cross sections for intratrap collisions and for collisions between trapped species and externally introduced particles. Trap depth often plays an important role in the interpretation of these measurements. A well-studied example of this is the large intensity-dependent variation displayed by the two-body intratrap loss-rate coefficient for atoms trapped in a magnetooptical trap (MOT). This variation results from an interplay of trap depth and the energy imparted to trapped atoms due to hyperfine or fine structure changing collisions, as well as radiative escape [1][2][3][4][5][6][7][8][9][10][11][12]. More recently, inelastic and elastic collision rates in dipole traps have been of interest, particularly for metastable species [13,14]. The fraction of elastic collisions resulting in an evaporated atom depends on trap depth, which is a key parameter for evaporative cooling [13,15,16]. The lifetime dependence of a state-insenstive dipole trap on trap depth for cesium atoms has also recently been investigated [17]. Of course the most fundamental role of trap depth is that it be large enough to provide sufficient confinement, which has been an issue for experiments with buffer-gas-cooled atoms or molecules [18,19].In recent years there has been interest in making precision determinations of collision cross-sections from measurements of particle loss rates due to externally introduced particles. These measurements involve collisions of trapped neutral particles with neutral atoms and molecules [20][21][22][23][24], electron beams [25][26][27], and trapped ions [28][29][30]. Photoionization cross sections have also been investigated though mea...

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Measurement of low-energy total absolute atomic collision cross sections with the metastableP23state of neon using a magneto-optical trap

Cited by 21 publications

References 29 publications

Vacuum-pressure measurement using a magneto-optical trap

Vacuum-pressure measurement using a magneto-optical trap

Photoionization dynamics of excited Ne, Ar, Kr and Xe atoms near threshold

Trap-depth determination from residual gas collisions

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