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Production of Cold Antihydrogen with ATHENA for Fundamental Studies  [PDF]
ATHENA Collaboration,A. Kellerbauer,M. Amoretti,C. Amsler,G. Bonomi,P. D. Bowe,C. Canali,C. Carraro,C. L. Cesar,M. Charlton,M. Doser,A. Fontana,M. C. Fujiwara,R. Funakoshi,P. Genova,J. S. Hangst,R. S. Hayano,I. Johnson,L. V. J?rgensen,V. Lagomarsino,R. Landua,E. Lodi Rizzini,M. Macrí,N. Madsen,G. Manuzio,D. Mitchard,P. Montagna,H. Pruys,C. Regenfus,A. Rotondi,G. Testera,A. Variola,L. Venturelli,D. P. van der Werf,Y. Yamazaki,N. Zurlo
Physics , 2004,
Abstract: Since the beginning of operations of the CERN Antiproton Decelerator in July 2000, the successful deceleration, storage and manipulation of antiprotons has led to remarkable progress in the production of antimatter. The ATHENA Collaboration were the first to create and detect cold antihydrogen in 2002, and we can today produce large enough amounts of antiatoms to study their properties as well as the parameters that govern their production rate.
The First Cold Antihydrogen  [PDF]
M. C. Fujiwara,M. Amoretti,C. Amsler,G. Bonomi,A. Bouchta,P. D. Bowe,C. Carraro,C. L. Cesar,M. Charlton,M. Doser,V. Filippini,A. Fontana,R. Funakoshi,P. Genova,J. S. Hangst,R. S. Hayano,L. V. Jorgensen,V. Lagomarsino,R. Landua,D. Lindelof,E. Lodi Rizzini,M. Macri,N. Madsen,M. Marchesotti,P. Montagna,H. Pruys,C. Regenfus,P. Rielder,A. Rotondi,G. Testera,A. Variola,D. P. van der Werf
Physics , 2004, DOI: 10.1016/j.nima.2004.06.050
Abstract: Antihydrogen, the atomic bound state of an antiproton and a positron, was produced at low energy for the first time by the ATHENA experiment, marking an important first step for precision studies of atomic antimatter. This paper describes the first production and some subsequent developments.
First Production and Detection of Cold Antihydrogen Atoms  [PDF]
M. C. Fujiwara,M. Amoretti,C. Amsler,G. Bonomi,A. Bouchta,P. Bowe,C. Carraro,C. L. Cesar,M. Charlton,M. Doser,V. Filippini,A. Fontana,R. Funakoshi,P. Genova,J. S. Hangst,R. S. Hayano,L. V. Jorgensen,V. Lagomarsino,R. Landua,D. Lindelof,E. Lodi Rizzini,M. Marchesotti,M. Macri,N. Madsen,P. Montagna,H. Pruys,C. Regenfus,P. Rielder,A. Rotondi,G. Testera,A. Variola,D. P. van der Werf
Physics , 2003, DOI: 10.1016/S0168-583X(03)01775-0
Abstract: The ATHENA experiment recently produced the first atoms of cold antihydrogen. This paper gives a brief review of how this was achieved.
Positron plasma diagnostics and temperature control for antihydrogen production  [PDF]
ATHENA Collaboration,M. Amoretti,C. Amsler,G. Bonomi,A. Bouchta,P. D. Bowe,C. Carraro,C. L. Cesar,M. Charlton,M. Doser,V. Filippini,A. Fontana,M. C. Fujiwara,R. Funakoshi,P. Genova,J. S. Hangst,R. S. Hayano,L. V. Jorgensen,V. Lagomarsino,R. Landua,D. Lindelof,E. Lodi Rizzini,M. Macri',N. Madsen,G. Manuzio,P. Montagna,H. Pruys,C. Regenfus,A. Rotondi,G. Testera,A. Variola,D. P. van der Werf
Physics , 2003, DOI: 10.1103/PhysRevLett.91.055001
Abstract: Production of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss non-destructive measurements, based on a novel, real-time analysis of excited, low-order plasma modes, that provide comprehensive characterization of the positron plasma in the ATHENA antihydrogen apparatus. The plasma length, radius, density, and total particle number are obtained. Measurement and control of plasma temperature variations, and the application to antihydrogen production experiments are discussed.
Producing Slow Antihydrogen for a Test of CPT Symmetry with ATHENA  [PDF]
ATHENA Collaboration,M. C. Fujiwara
Physics , 2002,
Abstract: The ATHENA experiment at the Antiproton Decelerator facility at CERN aims at testing CPT symmetry with antihydrogen. An overview of the experiment, together with preliminary results of development towards the production of slow antihydrogen are reported.
Cold-Antimatter Physics  [PDF]
ATHENA Collaboration,M. Amoretti,C. Amsler,G. Bonomi,P. D. Bowe,C. Canali,C. Carraro,C. L. Cesar,M. Charlton,M. Doser,A. Fontana,M. C. Fujiwara,R. Funakoshi,P. Genova,J. S. Hangst,R. S. Hayano,I. Johnson,L. V. Jorgensen,A. Kellerbauer,V. Lagomarsino,R. Landua,E. Lodi Rizzini,M. Macri,N. Madsen,G. Manuzio,D. Mitchard,P. Montagna,H. Pruys,C. Regenfus,A. Rotondi,G. Testera,A. Variola,L. Venturelli,D. P. van der Werf,Y. Yamazaki,N. Zurlo
Physics , 2005,
Abstract: The CPT theorem and the Weak Equivalence Principle are foundational principles on which the standard description of the fundamental interactions is based. The validity of such basic principles should be tested using the largest possible sample of physical systems. Cold neutral antimatter (low-energy antihydrogen atoms) could be a tool for testing the CPT symmetry with high precision and for a direct measurement of the gravitational acceleration of antimatter. After several years of experimental efforts, the production of low-energy antihydrogen through the recombination of antiprotons and positrons is a well-established experimental reality. An overview of the ATHENA experiment at CERN will be given and the main experimental results on antihydrogen formation will be reviewed.
Controlled Antihydrogen Propulsion for NASA's Future in Very Deep Space  [PDF]
Michael Martin Nieto,Michael H. Holzscheiter,Slava G. Turyshev
Physics , 2004,
Abstract: To world-wide notice, in 2002 the ATHENA collaboration at CERN (in Geneva, Switzerland) announced the creation of order 100,000 low energy antihydrogen atoms. Thus, the concept of using condensed antihydrogen as a low-weight, powerful fuel (i.e., it produces a thousand times more energy per unit weight of fuel than fission/fusion) for very deep space missions (the Oort cloud and beyond) had reached the realm of conceivability. We briefly discuss the history of antimatter research and focus on the technologies that must be developed to allow a future use of controlled, condensed antihydrogen for propulsion purposes. We emphasize that a dedicated antiproton source (the main barrier to copious antihydrogen production) must be built in the US, perhaps as a joint NASA/DOE/NIH project. This is because the only practical sources in the world are at CERN and the proposed facility at GSI in Germany. We outline the scope and magnitude of such a dedicated national facility and identify critical project milestones. We estimate that, starting with the present level of knowledge and multi-agency support, the goal of using antihydrogen for propulsion purposes may be accomplished in ~50 years.
Detecting Antihydrogen: The Challenges and the Applications  [PDF]
Makoto C. Fujiwara
Physics , 2005, DOI: 10.1063/1.2121974
Abstract: ATHENA's first detection of cold antihydrogen atoms relied on their annihilation signatures in a sophisticated particle detector. We will review the features of the ATHENA detector and its applications in trap physics. The detector for a new experiment ALPHA will have considerable challenges due to increased material thickness in the trap apparatus as well as field non-uniformity. Our studies indicate that annihilation vertex imaging should be still possible despite these challenges. An alternative method for trapped antihydrogen, via electron impact ionization, will be also discussed.
Production of antihydrogen at reduced magnetic field for anti-atom trapping  [PDF]
G B Andresen,W Bertsche,A Boston,P D Bowe,C L Cesar,S Chapman,M Charlton,M Chartier,A Deutsch,J Fajans,M C Fujiwara,R Funakoshi,D R Gill,K Gomberoff,J S Hangst,R S Hayano,R Hydomako,M J Jenkins,L V Jorgensen,L Kurchaninov,N Madsen,P Nolan,K Olchanski,A Olin,R D Page,A Povilus,F Robicheaux,E Sarid,D M Silveira,J W Storey,R I Thompson,D P van derWerf,J S Wurtele,Y Yamazaki
Physics , 2008, DOI: 10.1088/0953-4075/41/1/011001
Abstract: We have demonstrated production of antihydrogen in a 1$,$T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3$,$T) and ATRAP (5$,$T). The motivation for using a smaller magnetic field is to facilitate trapping of antihydrogen atoms in a neutral atom trap surrounding the production region. We report the results of measurements with the ALPHA (Antihydrogen Laser PHysics Apparatus) device, which can capture and cool antiprotons at 3$,$T, and then mix the antiprotons with positrons at 1$,$T. We infer antihydrogen production from the time structure of antiproton annihilations during mixing, using mixing with heated positrons as the null experiment, as demonstrated in ATHENA. Implications for antihydrogen trapping are discussed.
Antihydrogen Formation, Trapping and Dynamics  [PDF]
Eoin Butler
Physics , 2011,
Abstract: Antihydrogen, the simplest pure-antimatter atomic system, holds the promise of direct tests of matter-antimatter equivalence and CPT invariance, two of the outstanding unanswered questions in modern physics. Antihydrogen is now routinely produced in charged-particle traps through the combination of plasmas of antiprotons and positrons, but the atoms escape and are destroyed in a minuscule fraction of a second. The focus of this work is the production of a sample of cold antihydrogen atoms in a magnetic atom trap. This poses an extreme challenge, because the state-of-the-art atom traps are only approximately 0.5 K deep for ground-state antihydrogen atoms, much shallower than the energies of particles stored in the plasmas. This thesis will outline the main parts of the ALPHA experiment, with an overview of the important physical processes at work. Antihydrogen production techniques will be described, and an analysis of the spatial annihilation distribution to give indications of the temperature and binding energy distribution of the atoms will be presented. Finally, we describe the techniques needed to demonstrate confinement of antihydrogen atoms, apply them to a data taking run and present the results, making a definitive identification of trapped antihydrogen atoms.
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