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1.
A continuous cold atomic beam from a magneto-optical trap 总被引:3,自引:0,他引:3
L. Cacciapuoti A. Castrillo M. de Angelis G.M. Tino 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(2):245-249
We have developed and characterized a new method to produce a continuous beam of cold atoms from a standard vapour-cell magneto-optical
trap (MOT). The experimental apparatus is very simple. Using a single laser beam it is possible to hollow out in the source
MOT a direction of unbalanced radiation pressure along which cold atoms can be accelerated out of the trap. The transverse
cooling process that takes place during the extraction reduces the beam divergence. The atomic beam is used to load a magneto-optical
trap operating in an ultra-high vacuum environment. At a vapour pressure of 10-8mbar in the loading cell, we have produced a continuous flux of 7×107atoms/s at the recapture cell with a mean velocity of 14 m/s. A comparison of this method with a pulsed transfer scheme is
presented.
Received 19 February 2001 相似文献
2.
Cold atomic beam from a rubidium funnel 总被引:1,自引:0,他引:1
We report an experimental demonstration of a continuous, slow and cold beam of rubidium atoms from a two-dimensional magneto-optic
trap or atomic funnel. Typically 7.3(7)×108 atoms/s are ejected from the funnel with a variable velocity in the range 2–8 m/s and a temperature of 45–55 μK in the moving
frame. This represents the first demonstration of sub-Doppler laser cooling in an atomic beam and temperatures as low as ≈25 μK
have been observed.
Received: 30 September 1999 / Published online: 5 April 2000 相似文献
3.
P. Cren C.F. Roos A. Aclan J. Dalibard D. Guéry-Odelin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(1):107-116
We demonstrate experimentally the continuous and pulsed loading of a slow and cold atomic beam into a magnetic guide. The
slow beam is produced using a vapor loaded laser trap, which ensures two-dimensional magneto-optical trapping, as well as
cooling by a moving molasses along the third direction. It provides a continuous flux larger than 109 atoms/s with an adjustable mean velocity ranging from 0.3 to 3 m/s, and with longitudinal and transverse temperatures smaller
than 100 μK. Up to 3×108 atoms/s are injected into the magnetic guide and subsequently guided over a distance of 40 cm.
Received 19 February 2002 Published online 28 June 2002 相似文献
4.
高强度的亚稳态惰性原子束流在原子分子物理实验研究中具有广泛的应用.使用射频电离方法和激光横向冷却技术制备了高强度的亚稳态氪原子束流,并使用数值模拟方法对横向冷却激光场中的原子径迹进行了分析.通过激光诱导荧光光谱方法测量原子束的束流特性,结果显示,横向冷却后在束流源下游230 cm处的原子束流强度达1.6atoms/(s*sr),束流强度提高了两个量级.利用这种高强度原子束流,我们成功囚禁了1.3×1010个亚稳态84Kr原子,同时冷原子装载速率达到了3.0×1011atoms/s;并利用该装置成功地实现了高亮度的亚稳态氩原子束和原子阱.
关键词:
横向冷却
原子束
原子阱
惰性气体 相似文献
5.
6.
We demonstrate an experimental setup for the production of a beam source of cold 87Rb atoms. The atoms are extracted from a trapped cold atomic cloud in an unbalanced three-dimensional magneto-optical trap. Via a radiation pressure difference generated by a specially designed leak tunnel along one trapping laser beam, the atoms are pushed out continuously with low velocities and a high flux. The most-probable velocity in the beam is varied from 9 m/s to 19 m/s by varying the detuning of the trapping laser beams in the magneto-optical trap and the flux can be tuned up to 4×109 s-1 by increasing the intensity of the trapping beams. We also present a simple model for describing the dependence of the beam performance on the magneto-optical trap trapping laser intensity and the detuning. 相似文献
7.
W. v. Drachenfels U. T. Koch R. D. Lepper T. M. Müller W. Paul 《Zeitschrift für Physik A Hadrons and Nuclei》1974,269(4):387-397
A pulsed polarized electron source using the Fano effect on cesium is described in detail. A frequency doubled dye laser producing 2 mJ/pulse at 305 nm is used as the source of circularly polarized light. The light beam interacts with an array of 20 atomic beams. The atomic beam oven operates in a closed cycle thereby increasing running time by a factor of 30. Intensities of 3×109 e ?/0.5 μs with a polarization of 90% have been routinely obtained. 相似文献
8.
We have investigated the all-optical generation of ions by photo-ionisation of atoms generated by pulsed laser ablation. A
direct comparison between a resistively heated oven source and pulsed laser ablation is reported. Pulsed laser ablation with
10 ns Nd:YAG laser pulses is shown to produce large calcium flux, corresponding to atomic beams produced with oven temperatures
greater than 650 K. For an equivalent atomic flux, pulsed laser ablation is shown to produce a thermal load more than one
order of magnitude smaller than the oven source. The atomic beam distributions obey Maxwell–Boltzmann statistics with most
probable speeds corresponding to temperatures greater than 2200 K. Below a threshold pulse fluence between 280 mJ/cm2 and 330 mJ/cm2, the atomic beam is composed exclusively of ground-state atoms. For higher fluences ions and excited atoms are generated. 相似文献
9.
N. Kjaergaard L. Hornekaer A.M. Thommesen Z. Videsen M. Drewsen 《Applied physics. B, Lasers and optics》2000,71(2):207-210
We have demonstrated that resonance-enhanced two-photon ionization of atomic beams provides an effective tool for isotope
selective loading of ions into a linear Paul trap. Using a tunable, narrow-bandwidth, continuous wave (cw) laser system for
the ionization process, we have succeeded in producing Mg+ and Ca+ ions at rates controlled by the atomic beam flux, the laser intensity, and the laser frequency detuning from resonance. We
have observed that with a proper choice of control parameters, it is rather easy to load a specific number of ions into a
string. This observation has direct applications in quantum optics and quantum computation experiments. Furthermore, resonant
photo-ionization loading facilitates the formation of large isotope-pure Coulomb crystals.
Received: 21 December 1999 / Published online: 11 May 2000 相似文献
10.
G. Fuhr C. Reichle T. Müller K. Kahlke K. Schütze M. Stuke 《Applied Physics A: Materials Science & Processing》1999,69(6):611-616
An electric cage-laser micro-turning lathe was realised and applied to contact-free handling and mechanical processing of
micro particles. Since particles with diameters of several micrometers cannot be fixed in mechanical chucks, an octode field
cage was used to trap and rotate a single particle in a fluid without any mechanical surface contact. A pulsed nitrogen laser
of high beam quality focused to about 1 μm in diameter could be adjusted independently of the cage position. The trapping
forces (negative dielectrophoresis) acting on a bead of 5 to 15 μm are up to several hundred pN. This and the surrounding
fluid damp down the effect of the laser pulses during bead processing. Examples demonstrating the possibilities of this technique
are shown. Microsystems with high optical quality were fabricated photolithographically or by laser direct-write chemical
vapor deposition (LCVD). Technical and biotechnological applications are discussed.
Received: 20 October 1999 / Accepted: 27 October 1999 / Published online: 10 November 1999 相似文献
11.
We have established a caesium double magneto-optical trap (MOT) system for
cavity-QED experiment, and demonstrated the continuous transfer of cold caesium
atoms from the vapour-cell MOT with a pressure of ~ 1×10-6 Pa to
the ultra-high-vacuum (UHV) MOT with a pressure of ~ 8×10-8 Pa via a
focused continuous-wave transfer laser beam. The effect of frequency detuning as
well as the intensity of the transfer beam is systematically investigated, which
makes the transverse cooling adequate before the atoms leak out of the vapour-cell
MOT to reduce divergence of the cold atomic beam. The typical cold atomic flux got
from vapour-cell MOT is ~2×107 atoms/s. About 5×106
caesium atoms are recaptured in the UHV MOT. 相似文献
12.
Atomic beam guide by a one-dimensional magneto-optical trap 总被引:1,自引:0,他引:1
An atomic beam has been collimated, compressed, and deflected simultaneously by an atomic beam guide based on an inclined
one-dimensional magneto-optical trap (1D-MOT). Isotope-selected rubidium atoms were extracted from the naturally-mixed thermal
atomic beam with this method. We could manipulate the transverse displacement of the deflected beam precisely by adjusting
the current in the copper rods to generate the quadrupole magnetic field. We could extract more than 50% of the incident atoms
as a deflection beam when we combined this deflection technique with the atomic deceleration using a broadband spectral light.
Received: 10 December 1998 / Published online: 24 June 1999 相似文献
13.
S. Gulde D. Rotter P. Barton F. Schmidt-Kaler R. Blatt W. Hogervorst 《Applied physics. B, Lasers and optics》2001,73(8):861-863
We report a simple and efficient method to load a Paul trap with Ca+ ions. A beam of neutral atomic calcium is ionized in a two-step photo-ionization process using uv-diode lasers near 423 nm
and 390 nm. Photo-ionization of a calcium beam for loading a Paul trap has first been demonstrated by Kjaergaard et al. The
advantages of our method are the use of cheap and easily handled diode-laser systems and the large cross section for field
ionization when exciting high-lying Rydberg states. Finally, we discuss the advantages of photo-ionization for ion generation
compared to loading by electron bombardment.
Received: 24 August 2001 / Revised version: 16 October 2001 / Published online: 23 November 2001 相似文献
14.
P. N. Melentiev P. A. Borisov S. N. Rudnev A. E. Afanasiev V. I. Balykin 《JETP Letters》2006,83(1):14-18
A method for focusing neutral atoms based on the light-pressure force in a nonuniform magnetic field is proposed and analyzed.
Its particular scheme is realized by means of a two-dimensional magneto-optical trap using a thermal beam of Rb atoms. A feature
of this focusing method is the linear dependence of the focal length on the longitudinal velocity of atoms in contrast to
the quadratic dependence in the known methods of focusing material-particle beams. The minimum size of the waist of the focused
atomic beam is equal to 270 μm. Owing to focusing by means of the two-dimensional magneto-optical trap, the velocity monochromatization
of a thermal atomic beam is realized: the width of the distribution of the longitudinal atomic velocities in the beam is reduced
from 350 to 60 m/s.
Original Russian Text ? P.N. Melentiev, P.A. Borisov, S.N. Rudnev, A.E. Afanasiev, V.I. Balykin, 2006, published in Pis’ma
v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2006, Vol. 83, No. 1, pp. 16–20. 相似文献
15.
16.
We have produced and characterised a slow, bright and intense atomic beam of metastable helium atoms, suitable for atomic
physics experiments. The maximum continuous flux attained was 2×1010 atoms/s, while a typical longitudinal peak velocity of the beam was ∼26 m/s with a divergence in the range of 15 mrad to
30 mrad.
PACS 32.80.Pj; 32.80.Lg; 39.10.+j 相似文献
17.
J. Riedel S. Hoekstra W. Jäger J. J. Gilijamse S. Y. T. van de Meerakker G. Meijer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(1-2):161-166
Here we report on the accumulation of ground-state NH molecules in a static magnetic trap. A pulsed supersonic beam of NH (a1Δ) radicals is produced and brought to a near standstill at the center of a quadrupole magnetic trap using a Stark decelerator. There, optical pumping of the metastable NH radicals to the X3Σ? ground state is performed by driving the spin-forbidden A3Π ← a1Δ transition, followed by spontaneous A → X emission. The resulting population in the various rotational levels of the ground state is monitored via laser induced fluorescence detection. A substantial fraction of the ground-state NH molecules stays confined in the several milliKelvin deep magnetic trap. The loading scheme allows one to increase the phase-space density of trapped molecules by accumulating packets from consecutive deceleration cycles in the trap. In the present experiment, accumulation of six packets is demonstrated to result in an overall increase of only slightly over a factor of two, limited by the trap-loss and reloading rates. 相似文献
18.
Rydberg hydrogen atom in the presence of uniform magnetic and quadrupolar electric fields 总被引:1,自引:0,他引:1
Laser cooling and trapping offers the possibility of confining a sample of radioactive atoms in free space. Here, we address the question of how best to take advantage of cold atom properties to perform the observation of as highly forbidden a line as the 6S-7S Cs transition for achieving, in the longer term, atomic parity violation (APV) measurements in radioactive alkali isotopes. Another point at issue is whether one might do better with stable, cold atoms than with thermal atoms. To compensate for the large drawback of the small number of atoms available in a trap, one must take advantage of their low velocity. To lengthen the time of interaction with the excitation laser, we suggest choosing a geometry where the laser beam exciting the transition is colinear to a slow, cold atomic beam, either extracted from a trap or prepared by Zeeman slowing. We also suggest a new observable physical quantity manifesting APV, which presents several advantages: specificity, efficiency of detection, possibility of direct calibration by a parity conserving quantity of a similar nature. It is well adapted to a configuration where the cold atomic beam passes through two regions of transverse, crossed electric fields, leading both to differential measurements and to strong reduction of the contributions from the M1-Stark interference signals, potential sources of systematics in APV measurements. Our evaluation of signal-to-noise ratios shows that with available techniques, measurements of transition amplitudes, important as required tests of atomic theory, should be possible in 133Cs with a statistical precision of 10-3 and probably also in Fr isotopes for production rates of
Fr atoms s-1. For APV measurements to become realistic, some practical realization of the collimation of the atomic beam as well as multiple passages of the excitation beam matching the atomic beam looks essential.Received: 5 March 2003, Published online: 17 July 2003PACS:
32.80.Ys Weak-interaction effects in atoms - 32.70.Cs Oscillator strengths, lifetimes, transition moments - 32.80.Pj Optical cooling of atoms; trapping - 39.90.+d Other instrumentation and techniques for atomic and molecular physicsS. Sanguinetti: Also at E. Fermi Physics Dept., Pisa Univ., Pisa, Italy. 相似文献
19.
We transfer cold ^87 Rb atoms from a vapour cell chamber to a spatially separated UHV magneto-optical trap (MOT) with the assistance of a red-detuned optical guiding beam and a normal push beam. Efficient optical guiding of the cold atoms is observed within a small detuning window. A pulsed optical guiding beam enhances the transfer efficiency and hence allows us to collect more atoms in UHV MOT in a shorter time, which is favourable for our experiment of achieving Bose-Einstein condensates (BEC). Besides the easy operation, another advantage of this optical guiding technique is also demonstrated such that slower atomic beams may be efficiently transferred along horizontal direction. This study is a direct application of the optical guiding technique as a powerful tool. 相似文献
20.
K. Nagamine Y. Miyake P. Birrer K. Shimomura M. Iwasaki K. Nishiyama P. Strasser T. Kuga J. Marangos 《Hyperfine Interactions》1993,80(1-4):1287-1295
A concept, a design, a construction and an account of commissioning experiments are given for the recently completed ultra-slow muon facility at the pulsed muon facility of UT-MSL/KEK. The intense (more than 103/s) slow + beam with an extremely narrow phase-space volume (0.2 eV×(3 cm)2) to be produced in this facility will open a new muon science including surface physics and chemistry and fundamental atomic physics.Post-doctoral fellow of Swiss National Science Foundation. 相似文献