Advertisement

MAPAN

, Volume 27, Issue 1, pp 31–39 | Cite as

Measurement of Temperature of Atomic Cloud Using Time-of-Flight Technique

  • P. Arora
  • S. B. Purnapatra
  • A. Acharya
  • R. Kumar
  • A. Sen Gupta
Original Paper

Abstract

We present a discussion on the time-of-flight (TOF) technique for measuring temperature of cold atom clouds, with specific focus on fountain experiments. In these experiments, there exists a possibility of losing substantial number of atoms owing to the interaction of the cloud with the wall of the cavity, in case the dimension of the former exceeds the latter. Hence, we propose to include the contribution of the location and geometry of the cavity in the TOF method which otherwise, generally relies on the cloud shape and the geometry of the probe beams only. A theoretical analysis is presented and it is substantiated with experimental results for cloud temperatures of <10 μK and toss heights of up to 72 cm.

Keywords

Cold atoms Temperature measurement Time-of-flight 

References

  1. [1]
    H.J. Metcalf and P. Van Der Straten, Laser Cooling and Trapping, Springer, New York (1999).CrossRefGoogle Scholar
  2. [2]
    D.J. Wineland and W.M. Itano, Laser Cooling of Atoms, Phys. Rev A 20 (1979) 1521–1540.Google Scholar
  3. [3]
    D.J. Wineland and W.M. Itano, Laser Cooling, Phys. Today, TN156-TN162, June 1987.Google Scholar
  4. [4]
    P.D. Lett, R.N. Watts, C.I. Westbrook, W.D. Phillips, P.L. Gould and H.J. Metcalf, Observation of Atoms Laser Cooled Below the Doppler limit, Phys. Rev. Lett. 61 (1988) 169–172.ADSCrossRefGoogle Scholar
  5. [5]
    D.S. Weiss, E. Riis, Y. Shevy, P.J. Ungar, and S. Chu, Optical molasses and multilevel atoms: experiment. J. Opt. Soc. Am. B 6 (1989) 2072–2083.ADSCrossRefGoogle Scholar
  6. [6]
    T.M. Brzozowski, M. Maczynska, M. Zawada, J. Zachorowski and W. Gawlik, Time-of-flight Measurement of the Temperature of Cold Atoms for Short Trap-probe Beam Distances. J. Opt. B: Quantum Semiclassical Opt. 4 (2002) 62–66.ADSCrossRefGoogle Scholar
  7. [7]
    S. Pradhan and B.N. Jagatap, Measurement of Temperature of Laser Cooled Atoms by One-dimensional Expansion in a Magneto-optical Trap. Rev. Sci. Instrum. 79 (2008) 013101.ADSCrossRefGoogle Scholar
  8. [8]
    I. Yavin, M. Weel, A. Andreyuk and A. Kumarakrishnan, A Calculation of the Time-of-flight Distribution of Trapped Atoms, Am. J. Phys. 70 (2002) 149–152.ADSCrossRefGoogle Scholar
  9. [9]
    P. Kohns, P. Buch, W. Sueptitz, C. Csambal and Wertmer, On-line Measurement of Sub-Doppler Temperatures in a Rb Magneto-optical Trap by Trap Centre Oscillations, Eur. Phys. Lett. 22 (1993) 517–522.Google Scholar
  10. [10]
    C.I. Westbrook, R.N. Watts, C.E. Tanner, S.L. Rolston, W.D. Phillips, P.D. Lett and P.L. Gould, Localization of Atoms in a Three-dimensional Standing Wave, Phys. Rev. Lett. 65 (1990) 33–36.ADSCrossRefGoogle Scholar
  11. [11]
    J.-Y. Courtois, G. Grynberg, B. Lounis and P. Verkerk, Recoil-induced Resonances in Cesium: An Atomic Analog to the Free-Electron Laser, Phys. Rev. Lett. 72 (1994), 3017–3020.ADSCrossRefGoogle Scholar
  12. [12]
    M. Mitsunaga, M. Yamashita, M. Koashi and N. Iomoto, Temperature Diagnostics for Cold Sodium Atoms by Transient Four-wave Mixing, Opt. Lett. 23 (1998), 840–842.ADSCrossRefGoogle Scholar
  13. [13]
    A. Sen Gupta, A. Agarwal, P. Arora and K. Pant, Development of Cesium Fountain Frequency Standard at the National Physical Laboraory, India, Curr. Sci. 100 (2011) 1393–1399.Google Scholar

Copyright information

© Metrology Society of India 2012

Authors and Affiliations

  • P. Arora
    • 1
  • S. B. Purnapatra
    • 1
  • A. Acharya
    • 1
  • R. Kumar
    • 1
  • A. Sen Gupta
    • 1
  1. 1.Time and Frequency DivisionNational Physical Laboratory (CSIR-NPL)New DelhiIndia

Personalised recommendations