Author
M. Bell
Bio: M. Bell is an academic researcher. The author has contributed to research in topics: Electron capture & Electron. The author has an hindex of 1, co-authored 1 publications receiving 51 citations.
Topics: Electron capture, Electron, Laser cooling
Papers
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TL;DR: Simplified formulae for the capture of low-energy electrons by stationary protons are averaged over Maxwellian and "flattened" Maxwellian electron velocity distributions as discussed by the authors, which is more nearly appropriate for electron beams used in accelerator proton-beam cooling experiments.
Abstract: Simplified formulae for the capture of low-energy electrons by stationary protons are averaged over Maxwellian and "flattened" Maxwellian electron velocity distributions. The latter distribution is more nearly appropriate for electron beams used in accelerator proton-beam cooling experiments. Flattening increases the capture rate by a factor of about two. Similar formulae for the capture of antiprotons by protons are mentioned.
51 citations
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TL;DR: A comprehensive overview of electron cooling can be found in this paper, where the authors present a comprehensive coverage of the subject and summarizes the present knowledge. And they discuss possible future developments and refinements of the method, as well as the application of the merged parallel-beam arrangement for atomic physics.
249 citations
Max Planck Society1, Heidelberg University2, Katholieke Universiteit Leuven3, CERN4, University of Liverpool5, University of Edinburgh6, University of the West of Scotland7, Sofia University8, Technische Universität Darmstadt9, Bulgarian Academy of Sciences10, Petersburg Nuclear Physics Institute11, University of Manchester12, Technische Universität München13, Spanish National Research Council14, Frankfurt Institute for Advanced Studies15, University of Surrey16, Lund University17, Australian National University18, University of Mainz19, Complutense University of Madrid20, University of Helsinki21, University of Jyväskylä22, Goethe University Frankfurt23, Ludwig Maximilian University of Munich24, Michigan State University25, Chinese Academy of Sciences26, University of York27, Chalmers University of Technology28, University of Groningen29, Daresbury Laboratory30, Beihang University31, University of Warsaw32, University of Cologne33, Aarhus University34, Columbia University35, Lawrence Livermore National Laboratory36, Stockholm University37, Weizmann Institute of Science38, Helmholtz Institute Jena39, University of Jena40, Saitama University41, Dresden University of Technology42
TL;DR: In this article, the authors proposed to install a storage ring at an ISOL-type radioactive beam facility for the first time, which can provide a capability for experiments with stored secondary beams that is unique in the world.
Abstract: We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.
109 citations
TL;DR: In this paper, the electron-ion capture rate for low electron energies is calculated for various electron velocity distributions and the results are applied to electron cooling and to positron-antiproton recombination to form antihydrogen.
Abstract: The electron-ion capture rate for low electron energies is calculated for various electron velocity distributions. Capture rates for electron-ion recombination stimulated by irradiation with light are evaluated. The results are applied to electron cooling and to positron-antiproton recombination to form antihydrogen. It is shown that laser-induced capture is a powerful method to study the electron cooling process and to maximize the antihydrogen rate. With this technique a pulsed antihydrogen beam of selectable energy and well collimated with an intensity of a few atoms per second can be anticipated.
98 citations
02 Sep 1989-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: The Heidelberg heavy ion test storage ring TSR started operation in May 1988 and the first experiments were performed in 1989 as mentioned in this paper, where the lifetime of the ion beams observed in the first experiment can be explained by interactions with the residual gas.
Abstract: The Heidelberg heavy ion test storage ring TSR started operation in May 1988. The lifetimes of the ion beams observed in the first experiments can be explained by interactions with the residual gas. Multiple Coulomb scattering, single Coulomb scattering, electron capture and electron stripping are the relevant processes. Electron cooling of ions as heavy as O 8+ has been observed for the first time. With increasing particle number, the longitudinal Schottky noise spectrum becomes dominated by collective waves for cooled beams, allowing a determination of velocities of sound. After correcting for these coherent distortions fo the Schottky spectrum, the longitudinal beam temperature could be extracted. The observed longitudinal equilibrium beam temperatures increase strongly with the charge of the ions. For a cooled C 6+ beam, temperatures a factor of 120 higher were measured compared to a proton beam with the same particle number. The shrinking of the beam diameter due to electron cooling was observed with detectors which measured the profile of charge-changed ions behind a bending magnet. A strong laser-induced fluorescence was detected when storing metastable 7 Li + ions in the ring. Via the Doppler effect a very accurate measurement of the ion velocity profile could be performed. First attempts to observe laser cooling failed, probably due to heating effects from intrabeam scattering and a coupling between longitudinal and transversal motion in the beam. Several experiments under preparation are outlined.
90 citations
TL;DR: In this paper, the concept and field of antimatter and how quantum mechanics and relativity led to its discovery were discussed and how neutral antimatter, in the form of anti-hydrogen, is a natural test bed for tests of CPT and the weak equivalence principle, and how cold antihydrogen can be formed by creating, trapping, cooling and combining antiprotons and positrons at a facility such as the antiproton decelerator at CERN.
76 citations