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Title: Antimatter Plasmas in a Multipole Trap for Antihydrogen

Abstract

We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies.

Authors:
; ;  [1]; ; ; ; ; ;  [2]; ; ;  [3]; ;  [4]; ; ; ; ; ;  [5]
  1. Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)
  2. Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300 (United States)
  3. Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)
  4. Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21945-970 (Brazil)
  5. Department of Physics, University of Wales Swansea, Swansea SA2 8PP (United Kingdom) (and others)
Publication Date:
OSTI Identifier:
20861599
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevLett.98.023402; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANTIPROTONS; ATOMS; GROUND STATES; HYDROGEN; LIFETIME; MINIMUM-B CONFIGURATIONS; OCTUPOLES; PLASMA; POSITRONS; TEMPERATURE RANGE 0000-0013 K; TRAPPING; TRAPS

Citation Formats

Andresen, G., Bowe, P. D., Hangst, J. S., Bertsche, W., Chapman, S., Deutsch, A., Fajans, J., Povilus, A., Wurtele, J. S., Boston, A., Chartier, M., Nolan, P., Cesar, C. L., Silveira, D. M., Charlton, M., Jenkins, M. J., Joergensen, L. V., Madsen, N., Telle, H. H., and Werf, D. P. van der. Antimatter Plasmas in a Multipole Trap for Antihydrogen. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.023402.
Andresen, G., Bowe, P. D., Hangst, J. S., Bertsche, W., Chapman, S., Deutsch, A., Fajans, J., Povilus, A., Wurtele, J. S., Boston, A., Chartier, M., Nolan, P., Cesar, C. L., Silveira, D. M., Charlton, M., Jenkins, M. J., Joergensen, L. V., Madsen, N., Telle, H. H., & Werf, D. P. van der. Antimatter Plasmas in a Multipole Trap for Antihydrogen. United States. doi:10.1103/PHYSREVLETT.98.023402.
Andresen, G., Bowe, P. D., Hangst, J. S., Bertsche, W., Chapman, S., Deutsch, A., Fajans, J., Povilus, A., Wurtele, J. S., Boston, A., Chartier, M., Nolan, P., Cesar, C. L., Silveira, D. M., Charlton, M., Jenkins, M. J., Joergensen, L. V., Madsen, N., Telle, H. H., and Werf, D. P. van der. Fri . "Antimatter Plasmas in a Multipole Trap for Antihydrogen". United States. doi:10.1103/PHYSREVLETT.98.023402.
@article{osti_20861599,
title = {Antimatter Plasmas in a Multipole Trap for Antihydrogen},
author = {Andresen, G. and Bowe, P. D. and Hangst, J. S. and Bertsche, W. and Chapman, S. and Deutsch, A. and Fajans, J. and Povilus, A. and Wurtele, J. S. and Boston, A. and Chartier, M. and Nolan, P. and Cesar, C. L. and Silveira, D. M. and Charlton, M. and Jenkins, M. J. and Joergensen, L. V. and Madsen, N. and Telle, H. H. and Werf, D. P. van der},
abstractNote = {We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies.},
doi = {10.1103/PHYSREVLETT.98.023402},
journal = {Physical Review Letters},
number = 2,
volume = 98,
place = {United States},
year = {Fri Jan 12 00:00:00 EST 2007},
month = {Fri Jan 12 00:00:00 EST 2007}
}
  • ATRAP has made many important improvements since CERN's Antiproton Decelerator (AD) was restarted in 2006. These include substantial increases in the number of positrons (e{sup +}) and antiprotons (Pbars) used to make antihydrogen (Hbar) atoms, a new technique for loading electrons (e{sup -}) that are used to cool Pbars and e{sup +}, implementation of a completely new, larger and more robust apparatus in our second experimental zone and the inclusion of a quadrupole Ioffe trap intended to trap the coldest Hbar atoms produced. Using this new apparatus we have produced large numbers of Hbar atoms within a Penning trap thatmore » is located within this quadrupole Ioffe trap using a new technique which shows promise for producing even colder atoms. These observed Hbar atoms resolve a debate about whether positrons and antiprotons can be brought together to form atoms within the divergent magnetic fields of a quadrupole Ioffe trap.« less
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  • The merging of antiprotons with a positron plasma is the predominant and highest efficient method for cold antihydrogen formation used to date. We present experimental evidence that this method has serious disadvantages for producing antihydrogen cold enough to be trapped. Antihydrogen is neutral but may be trapped in a magnetic field minimum. However, the depth of such traps are of order 1 K, shallow compared to the kinetic energies in current antihydrogen experiments. Studying the spatial distribution of the antihydrogen emerging from the ATHENA positron plasma we have, by comparison with a simple model, extracted information about the temperature ofmore » the antihydrogen formed. We find that antihydrogen is formed before thermal equilibrium is attained between the antiprotons and the positrons, and thus that further positron cooling may not be sufficient for producing antihydrogen cold enough to be trapped. We discuss the implications for trapping of antihydrogen in a magnetic trap, important for ongoing work by the ALPHA collaboration.« less
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