Scientific Opportunities with a Rare-Isotope Facility in the United States (2007) / Chapter Skim
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3 Rare-Isotope Beams in the United States and Abroad
3 Rare-Isotope Beams in the United States and Abroad
Pages 68-83
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From page 68... ...
EXISTING RARE-ISOTOPE FACILITIES IN NORTH AMERICA United States: Selected Facilities At present the United States has world-leading capabilities in the study of exotic nuclei and an active research community currently performing experiments with exotic beams here and elsewhere in the world. Appendix C presents a tabular listing of most of the operating and planned rare-isotope beam facilities in the world.
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From page 69... ...
Other laboratories have capabilities to provide exotic beams: the Argonne Tandem Linear Accelerator System (ATLAS) at the Argonne National Laboratory (ANL)
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From page 70... ...
The tandem postaccelerator produces high-quality beams with energies up to 10 MeV/A at A ~ 40 and 5 MeV/A at A ~ 130. Experimental equipment at HRIBF includes the Recoil Mass Separator, which is used primarily for nuclear structure studies and is equipped at the target position with the Clover Array for Radioactive Ion Beams Ge detector array, near full-coverage, charged particle arrays, and neutron detectors, along with a variety of specialized detector systems at the focal plane for decay studies.
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From page 71... ...
Thus far, beams of 6He, 7Be, 8Li, 8B, 12B, 10Be, 12N, 18Ne, and 18F have been produced at energies typically on the order of 2 to 5 MeV/A and intensities of 105 to 107 ions per second. The Cyclotron Institute at Texas A&M University has, for some time, employed heavy-ion beams from the K500 cyclotron along with the Momentum Achromat Recoil Separator to produce exotic beams using the in-flight method.
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From page 72... ...
operate extensive programs in nuclear structure and astrophysics. Naturally, beam intensities at these facilities are, in general, much larger than intensities with exotic beams, allowing a more detailed investigation of the nuclei available for study.
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From page 73... ...
In this proposal, a second high-intensity proton beam line would be constructed to bring a second beam to ISAC. This proposed facility would then provide a unique testing facility for high-power targets and ion sources.
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From page 74... ...
, a magneto-optical atom trap for electroweak precision tests of the Standard Model. -- TITAN (TRIUMF Ion Trap Facility for Atomic and Nuclear Science)
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From page 75... ...
Studies of nuclear structure as well as astrophysics, as described in Chapter 2, will be the main focus at this RIBF facility. In addition, with the installation of a new storage ring, a high-precision mass measurement with ∆m/m = 10–6 is planned.
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From page 76... ...
Germany: Facility for Antiproton and Ion Research at GSI The central part of the Facility for Antiproton and Ion Research consists of two large superconducting synchrotrons and a complex system of storage rings that will deliver high-intensity ion beams up to 35 GeV per nucleon for experi ments with primary beams of ions up to uranium, as well as secondary (radioac tive) ion beams and antiprotons.
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From page 77... ...
The concept and design of the FAIR accelerator facility have been adapted to the requirements of the planned scientific programs. These requirements are as follows: • Beams of all ion species.
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From page 78... ...
-- an advisory committee of the European Science Foundation -- prepared a roadmap for the construction of nuclear physics research infrastructure in Europe. The committee recommended the construction of two next-generation rare-iso tope beam facilities that were under discussion in the region: FAIR at GSI, using in-flight fragmentation, and the GANIL/SPIRAL 2 radioactive-beam facility em ploying ISOL techniques.
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From page 79... ...
The production of high-intensity beams of neutron-rich nuclei will be based on fission of a uranium target induced by neutrons, obtained from a deuteron beam impinging on a graphite converter (up to 1014 fissions per second) or by a direct irradiation with a deuteron, 3He, or 4He beam.
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From page 80... ...
INTERNATIONAL COMPARISONS First-generation rare-isotope beam facilities have been operating in the three regions of the world where nuclear physics is most actively pursued, Europe, North America, and Asia, and several laboratories have undertaken significant upgrades to prepare second-generation facilities (GSI, TRIUMF, RIKEN, and the SPIRAL facility at GANIL in France)
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From page 81... ...
For instance, in the area of nuclear structure research, the NSAC subcommittee found the following with respect to the relative strengths of GSI and RIA: RIA strength: RIA's generally higher intensity of unstable nuclei, especially at the • limits of existence, will provide it with across the board advantages even in the capabilities it shares with GSI. The flexibility of the RIA concept allows the choice of production methods to be optimized for particular rare-isotope species that will, for example, have a major impact on studies of very heavy elements.
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From page 82... ...
The fast beam capability allows measurements of Coulomb break-up, but the method may only be useful for light isotope systems because of the complexity in struc ture and gamma-decay pattern of the resonance states.4 These comparisons, 10 in all, by the NSAC subommittee show unique ad vantages for both facilities in addressing a set of scientific issues rather similar to those listed in Chapter 2 of the present report. Moreover, FAIR will be a facility focusing on a broader set of issues than rare-isotope science, as it has relativistic stable ion beams, kaon beams, and antiproton beams, as well as rare-isotope beams.
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From page 83... ...
will be an important capability for measurements of masses approaching the neutron drip line. The addition of a 300 MeV electron storage ring to investigate the charge distribution of radioactive ion species will be a unique capability unmatched at any other facility.
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