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Andresen GB, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Cesar CL, Chapman S, Charlton M, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayano RS, Hayden ME, Humphries A, Hydomako R, Jonsell S, Kurchaninov L, Lambo R, Madsen N, Menary S, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, Silveira DM, So C, Storey JW, Thompson RI, van der Werf DP, Wilding D, Wurtele JS, Yamazaki Y. Evaporative cooling of antiprotons to cryogenic temperatures. Phys Rev Lett 2010; 105:013003. [PMID: 20867439 DOI: 10.1103/physrevlett.105.013003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Indexed: 05/29/2023]
Abstract
We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9 K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise CPT test on trapped antihydrogen is a long-standing goal.
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Affiliation(s)
- G B Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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2
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Zhang Z. Monte Carlo simulation of an antiproton annihilation detector system. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0423-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Gabrielse G, Larochelle P, Le Sage D, Levitt B, Kolthammer WS, McConnell R, Richerme P, Wrubel J, Speck A, George MC, Grzonka D, Oelert W, Sefzick T, Zhang Z, Carew A, Comeau D, Hessels EA, Storry CH, Weel M, Walz J. Antihydrogen production within a Penning-Ioffe trap. Phys Rev Lett 2008; 100:113001. [PMID: 18517780 DOI: 10.1103/physrevlett.100.113001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Indexed: 05/26/2023]
Abstract
Slow antihydrogen (H) is produced within a Penning trap that is located within a quadrupole Ioffe trap, the latter intended to ultimately confine extremely cold, ground-state H[over ] atoms. Observed H[over ] atoms in this configuration 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. The number of detected H atoms actually increases when a 400 mK Ioffe trap is turned on.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.
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5
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Gabrielse G, Larochelle P, Le Sage D, Levitt B, Kolthammer WS, Kuljanishvili I, McConnell R, Wrubel J, Esser FM, Glückler H, Grzonka D, Hansen G, Martin S, Oelert W, Schillings J, Schmitt M, Sefzick T, Soltner H, Zhang Z, Comeau D, George MC, Hessels EA, Storry CH, Weel M, Speck A, Nillius F, Walz J, Hänsch TW. Antiproton confinement in a Penning-Ioffe trap for antihydrogen. Phys Rev Lett 2007; 98:113002. [PMID: 17501048 DOI: 10.1103/physrevlett.98.113002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Indexed: 05/15/2023]
Abstract
Antiprotons (p[over]) remain confined in a Penning trap, in sufficient numbers to form antihydrogen (H[over ) atoms via charge exchange, when the radial field of a quadrupole Ioffe trap is added. This first demonstration with p[over] suggests that quadrupole Ioffe traps can be superimposed upon p[over] and e(+) traps to attempt the capture of H[over] atoms as they form, contrary to conclusions of previous analyses.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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6
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Andresen G, Bertsche W, Boston A, Bowe PD, Cesar CL, Chapman S, Charlton M, Chartier M, Deutsch A, Fajans J, Fujiwara MC, Funakoshi R, Gill DR, Gomberoff K, Hangst JS, Hayano RS, Hydomako R, Jenkins MJ, Jørgensen LV, Kurchaninov L, Madsen N, Nolan P, Olchanski K, Olin A, Povilus A, Robicheaux F, Sarid E, Silveira DM, Storey JW, Telle HH, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Antimatter plasmas in a multipole trap for antihydrogen. Phys Rev Lett 2007; 98:023402. [PMID: 17358606 DOI: 10.1103/physrevlett.98.023402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Indexed: 05/14/2023]
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.
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Affiliation(s)
- G Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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7
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Amoretti M, Amsler C, Bonomi G, Bowe PD, Canali C, Carraro C, Cesar CL, Charlton M, Ejsing AM, Fontana A, Fujiwara MC, Funakoshi R, Genova P, Hangst JS, Hayano RS, Jørgensen LV, Kellerbauer A, Lagomarsino V, Lodi Rizzini E, Macrì M, Madsen N, Manuzio G, Mitchard D, Montagna P, Posada LGC, Pruys H, Regenfus C, Rotondi A, Telle HH, Testera G, Van der Werf DP, Variola A, Venturelli L, Yamazaki Y, Zurlo N. Search for laser-induced formation of antihydrogen atoms. Phys Rev Lett 2006; 97:213401. [PMID: 17155742 DOI: 10.1103/physrevlett.97.213401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Indexed: 05/12/2023]
Abstract
Antihydrogen can be synthesized by mixing antiprotons and positrons in a Penning trap environment. Here an experiment to stimulate the formation of antihydrogen in the n = 11 quantum state by the introduction of light from a CO2 continuous wave laser is described. An overall upper limit of 0.8% with 90% C.L. on the laser-induced enhancement of the recombination has been found. This result strongly suggests that radiative recombination contributes negligibly to the antihydrogen formed in the experimental conditions used by the ATHENA Collaboration.
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Affiliation(s)
- M Amoretti
- Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova, Italy
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8
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Pohl T, Sadeghpour HR, Gabrielse G. New interpretations of measured antihydrogen velocities and field ionization spectra. Phys Rev Lett 2006; 97:143401. [PMID: 17155247 DOI: 10.1103/physrevlett.97.143401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Indexed: 05/12/2023]
Abstract
We present extensive Monte Carlo simulations, showing that cold antihydrogen (H) atoms are produced when antiprotons (p) are gently heated in the side wells of a nested Penning trap. The observed H with high energies, that had seemed to indicate otherwise, are instead explained by a surprisingly effective charge-exchange mechanism. We shed light on the previously measured field-ionization spectrum, and reproduce both the characteristic low-field power law as well as the enhanced H production at higher fields. The latter feature is shown to arise from H toms too deeply bound to be described as guiding center atoms, atoms with internally chaotic motion.
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Affiliation(s)
- T Pohl
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
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Hu SX, Vrinceanu D, Mazevet S, Collins LA. Molecular-dynamics simulations of cold antihydrogen formation in strongly magnetized plasmas. Phys Rev Lett 2005; 95:163402. [PMID: 16241799 DOI: 10.1103/physrevlett.95.163402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Indexed: 05/05/2023]
Abstract
Employing a high-order symplectic integrator and an adaptive time-step algorithm, we perform molecular-dynamics simulations of antihydrogen formation, in a cold plasma confined by a strong magnetic field, over time scales of microseconds. Sufficient positron-antiproton recombination events occur to allow a statistical analysis for various properties of the formed antihydrogen atoms. Giant-dipole states are formed in the initial stage of recombination. In addition to neutral atoms, we also observe antihydrogen positive ions (H(+)), in which two positrons simultaneously bind to an antiproton.
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Affiliation(s)
- S X Hu
- Theoretical Division, Los Alamos National Laboratory, New Mexico 87545, USA.
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Fajans J, Bertsche W, Burke K, Chapman SF, van der Werf DP. Effects of extreme magnetic quadrupole fields on penning traps and the consequences for antihydrogen trapping. Phys Rev Lett 2005; 95:155001. [PMID: 16241731 DOI: 10.1103/physrevlett.95.155001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Indexed: 05/05/2023]
Abstract
Measurements on electrons confined in a Penning trap show that extreme quadrupole fields destroy particle confinement. Much of the particle loss comes from the hitherto unrecognized ballistic transport of particles directly into the wall. The measurements scale to the parameter regime used by ATHENA and ATRAP to create antihydrogen, and suggest that quadrupoles cannot be used to trap antihydrogen.
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Affiliation(s)
- J Fajans
- Department of Physics, University of California at Berkeley, and the Lawrence Berkeley National Laboratory, Berkeley California 94720, USA
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Madsen N, Amoretti M, Amsler C, Bonomi G, Bowe PD, Carraro C, Cesar CL, Charlton M, Doser M, Fontana A, Fujiwara MC, Funakoshi R, Genova P, Hangst JS, Hayano RS, Jørgensen LV, Kellerbauer A, Lagomarsino V, Landua R, Lodi-Rizzini E, Macri M, Mitchard D, Montagna P, Pruys H, Regenfus C, Rotondi A, Testera G, Variola A, Venturelli L, van der Werf DP, Yamazaki Y, Zurlo N. Spatial distribution of cold antihydrogen formation. Phys Rev Lett 2005; 94:033403. [PMID: 15698264 DOI: 10.1103/physrevlett.94.033403] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Indexed: 05/24/2023]
Abstract
Antihydrogen is formed when antiprotons are mixed with cold positrons in a nested Penning trap. We present experimental evidence, obtained using our antihydrogen annihilation detector, that the spatial distribution of the emerging antihydrogen atoms is independent of the positron temperature and axially enhanced. This indicates that antihydrogen is formed before the antiprotons are in thermal equilibrium with the positron plasma. This result has important implications for the trapping and spectroscopy of antihydrogen.
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Affiliation(s)
- N Madsen
- Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
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12
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Storry CH, Speck A, Le Sage D, Guise N, Gabrielse G, Grzonka D, Oelert W, Schepers G, Sefzick T, Pittner H, Herrmann M, Walz J, Hänsch TW, Comeau D, Hessels EA. First laser-controlled antihydrogen production. Phys Rev Lett 2004; 93:263401. [PMID: 15697977 DOI: 10.1103/physrevlett.93.263401] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Indexed: 05/24/2023]
Abstract
Lasers are used for the first time to control the production of antihydrogen (H ). Sequential, resonant charge exchange collisions are involved in a method that is very different than the only other method used so far-producing slow H during positron cooling of antiprotons in a nested Penning trap. Two attractive features are that the laser frequencies determine the H binding energy, and that the production of extremely cold H should be possible in principle-likely close to what is needed for confinement in a trap, as needed for precise laser spectroscopy.
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Affiliation(s)
- C H Storry
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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