Hyperfine Interactions

, Volume 212, Issue 1–3, pp 61–67 | Cite as

Antihydrogen formation by autoresonant excitation of antiproton plasmas

  • William Alan Bertsche
  • G. B. Andresen
  • M. D. Ashkezari
  • M. Baquero-Ruiz
  • P. D. Bowe
  • P. T. Carpenter
  • E. Butler
  • C. L. Cesar
  • S. F. Chapman
  • M. Charlton
  • S. Eriksson
  • J. Fajans
  • T. Friesen
  • M. C. Fujiwara
  • D. R. Gill
  • A. Gutierrez
  • J. S. Hangst
  • W. N. Hardy
  • R. S. Hayano
  • M. E. Hayden
  • A. J. Humphries
  • J. L. Hurt
  • R. Hydomako
  • S. Jonsell
  • L. Kurchaninov
  • N. Madsen
  • S. Menary
  • P. Nolan
  • K. Olchanski
  • A. Olin
  • A. Povilus
  • P. Pusa
  • F. Robicheaux
  • E. Sarid
  • D. M. Silveira
  • C. So
  • J. W. Storey
  • R. I. Thompson
  • D. P. van der Werf
  • J. S. Wurtele
  • Y. Yamazaki
  • ALPHA Collaboration
Article

Abstract

In efforts to trap antihydrogen, a key problem is the vast disparity between the neutral trap energy scale (\(\sim\!50\,\upmu\mathrm{eV}\)), and the energy scales associated with plasma confinement and space charge (~1 eV). In order to merge charged particle species for direct recombination, the larger energy scale must be overcome in a manner that minimizes the initial antihydrogen kinetic energy. This issue motivated the development of a novel injection technique utilizing the inherent nonlinear nature of particle oscillations in our traps. We demonstrated controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm or tenuous plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination. The nature of this injection overcomes some of the difficulties associated with matching the energies of the charged species used to produce antihydrogen.

Keywords

Antihydrogen Plasma Nonlinear Dynamics 

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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • William Alan Bertsche
    • 1
  • G. B. Andresen
    • 2
  • M. D. Ashkezari
    • 3
  • M. Baquero-Ruiz
    • 4
  • P. D. Bowe
    • 2
  • P. T. Carpenter
    • 5
  • E. Butler
    • 6
  • C. L. Cesar
    • 7
  • S. F. Chapman
    • 4
  • M. Charlton
    • 1
  • S. Eriksson
    • 1
  • J. Fajans
    • 4
  • T. Friesen
    • 8
  • M. C. Fujiwara
    • 9
  • D. R. Gill
    • 9
  • A. Gutierrez
    • 10
  • J. S. Hangst
    • 2
  • W. N. Hardy
    • 10
  • R. S. Hayano
    • 11
  • M. E. Hayden
    • 3
  • A. J. Humphries
    • 1
  • J. L. Hurt
    • 5
  • R. Hydomako
    • 8
  • S. Jonsell
    • 12
  • L. Kurchaninov
    • 9
  • N. Madsen
    • 1
  • S. Menary
    • 13
  • P. Nolan
    • 14
  • K. Olchanski
    • 9
  • A. Olin
    • 9
  • A. Povilus
    • 4
  • P. Pusa
    • 14
  • F. Robicheaux
    • 5
  • E. Sarid
    • 15
  • D. M. Silveira
    • 16
  • C. So
    • 4
  • J. W. Storey
    • 9
  • R. I. Thompson
    • 8
  • D. P. van der Werf
    • 1
  • J. S. Wurtele
    • 4
    • 17
  • Y. Yamazaki
    • 16
    • 18
  • ALPHA Collaboration
  1. 1.Department of PhysicsSwansea UniversitySwanseaUK
  2. 2.Department of Physics and AstronomyAarhus UniversityAarhus CDenmark
  3. 3.Department of PhysicsSimon Fraser UniversityBurnabyCanada
  4. 4.Department of PhysicsUniversity of CaliforniaBerkeleyUSA
  5. 5.Department of PhysicsAuburn UniversityAuburnUSA
  6. 6.Physics DepartmentCERNGeneva 23Switzerland
  7. 7.Instituto de FísicaUniversidade Federal do Rio de JaneiroRio de JaneiroBrazil
  8. 8.Department of Physics and AstronomyUniversity of CalgaryCalgaryCanada
  9. 9.TRIUMFVancouverCanada
  10. 10.Department of Physics and AstronomyUniversity of British ColumbiaVancouverCanada
  11. 11.Department of PhysicsUniversity of TokyoTokyoJapan
  12. 12.Department of PhysicsStockholm UniversityStockholmSweden
  13. 13.Department of Physics and AstronomyYork UniversityTorontoCanada
  14. 14.Department of PhysicsUniversity of LiverpoolLiverpoolUK
  15. 15.Department of PhysicsNRCN-Nuclear Research Center NegevBeer ShevaIsrael
  16. 16.Atomic Physics LaboratoryRIKEN Advanced Science InstituteSaitamaJapan
  17. 17.Lawrence Berkeley National LaboratoryBerkeley, CAUSA
  18. 18.Graduate School of Arts and SciencesUniversity of TokyoTokyoJapan

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