Category: Publication Content Type
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Antiproton physics in the ELENA era
Antiproton physics in the ELENA era The programme of physics with low-energy antiprotons at CERN, the European Particle Physics Laboratory, has a long history, beginning with the inauguration of the Low Energy Antiproton Ring (LEAR) in 1982. That machine produced antiprotons decelerated to kinetic energies of a few MeV, an achievement made possible due to
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Enhanced Control and Reproducibility of Non-Neutral Plasmas
Enhanced Control and Reproducibility of Non-Neutral Plasmas The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma’s density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for
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Antihydrogen accumulation for fundamental symmetry tests
Antihydrogen accumulation for fundamental symmetry tests Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor
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Aspects of 1S-2S spectroscopy of trapped antihydrogen atoms
Aspects of 1S-2S spectroscopy of trapped antihydrogen atoms Antihydrogen atoms are now routinely trapped in small numbers. One of the purposes of this effort is to make precision comparisons of the 1 S -2 S transition in hydrogen and antihydrogen as a precision test of the CPT theorem. We investigate, through calculations and simulations, various
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Laser-Ablated Beryllium Ions For Cold Antihydrogen In ALPHA
Laser-Ablated Beryllium Ions For Cold Antihydrogen In ALPHA One of the best ways to study antimatter is to investigate antihydrogen, the bound state of an antiproton and a positron. Antihydrogen atoms do not exist naturally and must be synthesized in the lab by merging carefully-prepared plasmas of positrons and antiprotons. If the atoms are created
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Observation of the hyperfine spectrum of antihydrogen
Observation of the hyperfine spectrum of antihydrogen We report the observation of the hyperfine spectrum of antihydrogen. By exposing trapped antihydrogen to microwave radiation and scanning the microwave frequency over two distinct transitions, we are able to extract the ground state hyperfine splitting. From a series of measurements involving a total of 194 detected atoms,
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Tests Of Fundamental Symmetries With Trapped Antihydrogen
Tests Of Fundamental Symmetries With Trapped Antihydrogen Antihydrogen is the simplest pure antimatter atomic system, and it allows for direct tests of CPT symmetry as well as the weak equivalence principle. Furthermore, the study of antihydrogen may provide clues to the matter- antimatter asymmetry observed in the universe – one of the major unanswered questions
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Cold Antihydrogen Experiments And Radial Compression Of Antiproton Clouds In The ALPHA Apparatus At CERN
Cold Antihydrogen Experiments And Radial Compression Of Antiproton Clouds In The ALPHA Apparatus At CERN Antihydrogen is the simplest neutral antimatter atom. Precision comparisons between hydrogen and antihydrogen would provide stringent tests of CPT (charge conjugation/parity transformation/time reversal) invariance and the weak equivalence principle. In the last few years, the ALPHA collaboration has produced, and
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Observation of the 1S-2S transition in trapped antihydrogen
Observation of the 1S-2S transition in trapped antihydrogen We report the observation of the 1S-2S transition in magnetically trapped atoms of antihydrogen in the ALPHA-2 apparatus at CERN. We determine that the frequency of the transition, driven by two photons from a frequency stabilised laser at 243 nm, is consistent with that expected for hydrogen
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Antiproton cloud compression in the ALPHA apparatus at CERN
Antiproton cloud compression in the ALPHA apparatus at CERN We have observed a new mechanism for compression of a non-neutral plasma, where antiprotons embedded in an electron plasma are compressed by a rotating wall drive at a frequency close to the sum of the axial bounce and rotation frequencies. The radius of the antiproton cloud