Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Confinement of antihydrogen for 1,000 seconds

Abstract

Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter–antimatter symmetry. We have recently demonstrated trapping of antihydrogen atoms by releasing them after a confinement time of 172 ms. A critical question for future studies is: how long can anti-atoms be trapped? Here, we report the observation of anti-atom confinement for 1,000 s, extending our earlier results by nearly four orders of magnitude. Our calculations indicate that most of the trapped anti-atoms reach the ground state. Further, we report the first measurement of the energy distribution of trapped antihydrogen, which, coupled with detailed comparisons with simulations, provides a key tool for the systematic investigation of trapping dynamics. These advances open up a range of experimental possibilities, including precision studies of charge–parity–time reversal symmetry and cooling to temperatures where gravitational effects could become apparent.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: The ALPHA antihydrogen trap and its magnetic-field configuration.
Figure 2: Long-time confinement of antihydrogen.
Figure 3: Antihydrogen annihilation patterns and comparisons with simulations.
Figure 4: Dynamics of trapped antihydrogen from the standard simulation.

References

  1. Pohl, R. et al. The size of the proton. Nature 466, 213–216 (2010).

    ADS  Article  Google Scholar 

  2. Fee, M. S. et al. Measurement of the positronium 13S1–23S1 interval by continuous-wave two-photon excitation. Phys. Rev. Lett. 70, 1397–1400 (1993).

    ADS  Article  Google Scholar 

  3. Yamazaki, T. et al. Formation of long-lived gas-phase antiprotonic helium atoms and quenching by H2 . Nature 361, 238–240 (1993).

    ADS  Article  Google Scholar 

  4. Nakamura, K. et al. (Particle Data Group). Review of particle physics. J. Phys. G 37, 075021 (2010).

    ADS  Article  Google Scholar 

  5. Lüders, G. Proof of the TCP theorem. Ann. Phys. 2, 1–15 (1957).

    ADS  MathSciNet  Article  Google Scholar 

  6. Baur, G. et al. Production of antihydrogen. Phys. Lett. B 368, 251–258 (1996).

    ADS  Article  Google Scholar 

  7. Amoretti, M. et al. Production and detection of cold antihydrogen atoms. Nature 419, 456–459 (2002).

    ADS  Article  Google Scholar 

  8. Gabrielse, G. et al. Background-free observation of cold antihydrogen with field-ionization analysis of its states. Phys. Rev. Lett. 89, 213401 (2002).

    ADS  Article  Google Scholar 

  9. Hänsch, T. W. & Zimmermann, C. Laser spectroscopy of hydrogen and antihydrogen. Hyperfine Interact. 76, 47–57 (1993).

    ADS  Article  Google Scholar 

  10. Fujiwara, M. C. et al. Towards antihydrogen confinement with the ALPHA antihydrogen trap. Hyperfine Interact. 172, 81–89 (2006).

    ADS  Article  Google Scholar 

  11. Setija, I. D. et al. Optical cooling of atomic hydrogen in a magnetic trap. Phys. Rev. Lett. 70, 2257–2260 (1993).

    ADS  Article  Google Scholar 

  12. Eikema, K. S. E., Walz, J. & Hänsch, T. W. Continuous coherent Lyman-α excitation of atomic hydrogen. Phys. Rev. Lett. 86, 5679–5682 (2001).

    ADS  Article  Google Scholar 

  13. Kielpinski, D. Laser cooling of atoms and molecules with ultrafast pulses. Phys. Rev. A 73, 063407 (2006).

    ADS  Article  Google Scholar 

  14. Shlyapnikov, G. V., Walraven, J. T. & Surkov, E. L. Antihydrogen at sub-Kelvin temperatures. Hyperfine Interact. 76, 31–46 (1993).

    ADS  Article  Google Scholar 

  15. Surkov, E. L., Walraven, J. T. M. & Shlyapnikov, G. V. Collisionless motion of neutral particles in magnetostatic traps. Phys. Rev. A 49, 4778–4786 (1994).

    ADS  Article  Google Scholar 

  16. Andresen, G. B. et al. Trapped antihydrogen. Nature 468, 673–676 (2010).

    ADS  Article  Google Scholar 

  17. Migdall, A. L., Prodan, J. V. & Phillips, W. D. First observation of magnetically trapped neutral atoms. Phys. Rev. Lett. 54, 2596–2599 (1985).

    ADS  Article  Google Scholar 

  18. Helmerson, K., Martin, A. & Pritchard, D. E. Laser and rf spectroscopy of magnetically trapped neutral atoms. J. Opt. Soc. Am. B 9, 483–492 (1992).

    ADS  Article  Google Scholar 

  19. Willems, P. A. & Libbrecht, K. G. Creating long-lived neutral-atom traps in a cryogenic environment. Phys. Rev. A 51, 1403–1406 (1995).

    ADS  Article  Google Scholar 

  20. Hess, H. et al. Magnetic trapping of spin-polarized atomic hydrogen. Phys. Rev. Lett. 59, 672–675 (1987).

    ADS  Article  Google Scholar 

  21. Bowman, J. D. & Penttila, S. I. On the measurement of the neutron lifetime using ultracold neutrons in a vacuum quadrupole trap. J. Res. Natl Inst. Stand. Technol. 110, 361–366 (2005).

    Article  Google Scholar 

  22. Choi, J-H. et al. Magnetic trapping of long-lived cold Rydberg atoms. Phys. Rev. Lett. 95, 243001 (2005).

    ADS  Article  Google Scholar 

  23. Andresen, G. B. et al. Evaporative cooling of antiprotons to cryogenic temperatures. Phys. Rev. Lett. 105, 013003 (2010).

    ADS  Article  Google Scholar 

  24. Andresen, G. B. et al. Autoresonant excitation of antiproton plasmas. Phys. Rev. Lett. 106, 025002 (2011).

    ADS  Article  Google Scholar 

  25. Bertsche, W. et al. A magnetic trap for antihydrogen confinement. Nucl. Instrum. Methods A 566, 746–756 (2006).

    ADS  Article  Google Scholar 

  26. Andresen, G. B. et al. Antimatter plasmas in a multipole trap for antihydrogen. Phys. Rev. Lett. 98, 023402 (2007).

    ADS  Article  Google Scholar 

  27. Gabrielse, G. et al. First capture of antiprotons in a Penning trap: A kiloelectronvolt source. Phys. Rev. Lett. 57, 2504–2507 (1986).

    ADS  Article  Google Scholar 

  28. Huang, X-P. et al. Steady-state confinement of non-neutral plasmas by rotating electric fields. Phys. Rev. Lett. 78, 875–878 (1997).

    ADS  Article  Google Scholar 

  29. Andresen, G. B. et al. Compression of antiproton clouds for antihydrogen trapping. Phys. Rev. Lett. 100, 203401 (2008).

    ADS  Article  Google Scholar 

  30. Surko, C. M. & Greaves, R. G. Emerging science and technology of antimatter plasmas and trap-based beams. Phys. Plasmas 11, 2333–2348 (2004).

    ADS  Article  Google Scholar 

  31. Jørgensen, L. V. et al. New source of dense, cryogenic positron plasmas. Phys. Rev. Lett. 95, 025002 (2005).

    ADS  Article  Google Scholar 

  32. Andresen, G. B. et al. Antihydrogen formation dynamics in a multipolar neutral anti-atom trap. Phys. Lett. B 685, 141–145 (2010).

    ADS  Article  Google Scholar 

  33. Fujiwara, M. C. et al. Three-dimensional annihilation imaging of trapped antiprotons. Phys. Rev. Lett. 92, 065005 (2004).

    ADS  Article  Google Scholar 

  34. Fujiwara, M. C. et al. Particle physics aspects of antihydrogen studies with ALPHA at CERN. AIP Conf. Proc. 1037, 208–220 (2008).

    ADS  Article  Google Scholar 

  35. Fujiwara, M. C. Detecting antihydrogen: The challenges and the applications. AIP Conf. Proc. 793, 111–121 (2005).

    ADS  Article  Google Scholar 

  36. Andresen, G. B. et al. Search for trapped antihydrogen. Phys. Lett. B 695, 95–104 (2011).

    ADS  Article  Google Scholar 

  37. Gabrielse, G. et al. Antihydrogen production within a Penning–Ioffe trap. Phys. Rev. Lett. 100, 113001 (2008).

    ADS  Article  Google Scholar 

  38. Robicheaux, F. Atomic processes in antihydrogen experiments: A theoretical and computational perspective. J. Phys. B 41, 192001 (2008).

    ADS  Article  Google Scholar 

  39. Pohl, T., Sadeghpour, H. R. & Gabrielse, G. New interpretations of measured antihydrogen velocities and field ionization spectra. Phys. Rev. Lett. 97, 143401 (2006).

    ADS  Article  Google Scholar 

  40. Gabrielse, G. et al. Driven production of cold antihydrogen and the first measured distribution of antihydrogen states. Phys. Rev. Lett. 89, 233401 (2002).

    ADS  Article  Google Scholar 

  41. Glinsky, M. E. & O’Neil, T. M. Guiding center atoms: Three-body recombination in a strongly magnetized plasma. Phys. Fluids B 3, 1279–1293 (1991).

    ADS  Article  Google Scholar 

  42. Fujiwara, M. C. et al. Temporally controlled modulation of antihydrogen production and the temperature scaling of antiproton–positron recombination. Phys. Rev. Lett. 101, 053401 (2008).

    ADS  Article  Google Scholar 

  43. Gabrielse, G. et al. First measurement of the velocity of slow antihydrogen atoms. Phys. Rev. Lett. 93, 073401 (2004).

    ADS  Article  Google Scholar 

  44. Madsen, N. et al. Spatial distribution of cold antihydrogen formation. Phys. Rev. Lett. 94, 033403 (2005).

    ADS  Article  Google Scholar 

  45. Robicheaux, F. et al. Simulations of antihydrogen formation. Phys. Rev. A 70, 022510 (2004).

    ADS  Article  Google Scholar 

  46. Strasburger, K., Chojnacki, H. & Skolowska, A. Adiabatic potentials for the interaction of atomic antihydrogen with He and He+. J. Phys. B 38, 3091–3105 (2005).

    ADS  Article  Google Scholar 

  47. Armour, E. A. G. et al. The interaction of antihydrogen with simple atoms and molecules. Nucl. Instrum. Methods B 266, 363–368 (2008).

    ADS  Article  Google Scholar 

  48. Gregory, M. R. & Armour, E. A. G. Hydrogen molecule–antihydrogen scattering at very low energies. Nucl. Instrum. Methods B 266, 374–378 (2008).

    ADS  Article  Google Scholar 

  49. Cohen, J. S. Molecular effects on antiproton capture by H2 and the states of –p formed. Phys. Rev. A 56, 3583–3596 (1997).

    ADS  Article  Google Scholar 

  50. Topçu, T. & Robicheaux, F. Radiative cascade of highly excited hydrogen atoms in strong magnetic fields. Phys. Rev. A 73, 043405 (2006).

    ADS  Article  Google Scholar 

  51. Taylor, C. L., Zhang, J & Robicheaux, F. Cooling of Rydberg during radiative cascade. J. Phys. B 39, 4945–4959 (2006).

    ADS  Article  Google Scholar 

  52. Pohl, T., Sadeghpour, H. R., Nagata, Y. & Yamazaki, Y. Cooling by spontaneous decay of highly excited antihydrogen atoms in magnetic traps. Phys. Rev. Lett. 97, 213001 (2006).

    ADS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported in part by CNPq, FINEP/RENAFAE (Brazil), NSERC, NRC/TRIUMF, AIF, FQRNT (Canada), FNU (Denmark), ISF (Israel), MEXT (Japan), VR (Sweden), EPSRC, the Royal Society and the Leverhulme Trust (UK) and DOE, NSF (USA). We are grateful to the AD team for the delivery of a high-quality antiproton beam.

Author information

Authors and Affiliations

Consortia

Contributions

All authors contributed significantly to this work.

Corresponding authors

Correspondence to M. C. Fujiwara or J. S. Hangst.

Ethics declarations

Competing interests

The author declare no competing financial interests.

Additional information

A full list of authors appears at the end of this paper.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

The ALPHA Collaboration. Confinement of antihydrogen for 1,000 seconds. Nature Phys 7, 558–564 (2011). https://doi.org/10.1038/nphys2025

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys2025

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing