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Highlights from the first year of Odin observations
- 2003
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 402, s. L39-L46
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Tidskriftsartikel (refereegranskat)abstract
- Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H2O, H218O, NH3, 15NH3 and O2 are presented, with some insights into accompanying Odin Letters in this A&A issue. We focus on new results where Odin's high angular resolution, high frequency resolution, large spectrometer bandwidths, high sensitivity or/and frequency tuning capability are crucial: H2O mapping of the Orion KL, W3, DR21, S140 regions, and four comets; H2O observations of Galactic Centre sources, of shock enhanced H2O towards the SNR IC443, and of the candidate infall source IRAS 16293-2422; H218O detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH3 in Orion KL (outflow, ambient cloud and bar) and ρ Oph, and very recently, of 15NH3 in~Orion KL. Simultaneous sensitive searches for the 119 GHz line of O2 have resulted in very low abundance limits, which are difficult to accomodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H2O results, that the Odin and SWAS observational data sets are very consistently calibrated. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes), and the Centre National d'études Spatiales (CNES, France). The Swedish Space Corporation (SSC) has been the prime industrial contractor, and is also responsible for the satellite operation from its Odin Mission Control Centre at SSC in Solna and its Odin Control Centre at ESRANGE near Kiruna in northern Sweden. See also the SNSB Odin web page: http://www.snsb.se/eng_odin_intro.shtml
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| 2. |
- Borge, M. J. G., et al.
(författare)
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Asymmetry in the super-allowed beta-transitions of the A=9 isobars
- 2004
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Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 738:1-4 SUPPL., s. 206-210
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Tidskriftsartikel (refereegranskat)abstract
- We report here on the recent beta-decay studies of the A = 9 isobar made at ISOLDE/CERN. Mirror beta transitions in the A=9 chain are compared and a large asymmetry factor is deduced for the transitions to high excitation energy in Be-9 (11.8 MeV) and B-9 (12.2 MeV) fed in the beta-decay of Li-9 and C-9 respectively. It is shown that the asymmetry is not due to experimental problems or differences in the mechanisms of breakup or in the spin of the states. Only differences in the partial decay branches of the breakup channels have been found. As no asymmetry is found in the gs to gs transition it must be due to the particular structure of these excited states.
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| 3. |
- Borge, M. J. G., et al.
(författare)
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Beta-delayed multiparticle emission studies at ISOL-type facilities
- 2004
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Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 746, s. 243-243
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Konferensbidrag (refereegranskat)abstract
- We report here on the recent beta-decay studies made at ISOL-type Facilities to determine the multiparticle breakup mechanism of excited states in light nuclei by studying them in full kinematics. In particular the results obtained for the A = 9 isobars and the breakup of the 12.7 MeV state in C-12 of unnatural parity are discussed. The breakup of the latter has been debated since more than a decade. Mirror beta transitions in the A = 9 chain are compared and a large asymmetry factor is deduced for the transitions to high excitation energy in Be-9 (11.8 MeV) and B-9 (12.2 MeV) fed in the beta-decay of Li-9 and C-9 respectively. It is shown that the asymmetry is not due to experimental problems or differences in the mechanisms of breakup or in the spin of the states. As no asymmetry is found in the gs to gs transition it must be due to the particular structure of these excited states. The controversy on the breakup mechanism of the 12.7 MeV state is resolved.
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| 4. |
- Borge, M. J. G., et al.
(författare)
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Proton dripline studies at ISOLDE: Ar-31 and C-9
- 2002
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Ingår i: Nuclear Physics A. - 0375-9474. ; 701, s. 373C-377C
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Konferensbidrag (refereegranskat)abstract
- In this contribution examples of the application of new technologies to disentangle the mechanism of beta-delayed multiparticle emission are given. In particular the mechanism of beta-delayed two-proton emission from Ar-31 has been resolved and proved to be sequential, a preview of C-9-decay data is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 5. |
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| 6. |
- Habs, D., et al.
(författare)
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The REX-ISOLDE project
- 2000
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Ingår i: Hyperfine Interactions. - 0304-3843 .- 1572-9540. ; 129:1-4, s. 43-66
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Tidskriftsartikel (refereegranskat)abstract
- The Radioactive Beam Experiment REX-ISOLDE [1-3] is a pilot experiment at ISOLDE (CERN) testing the new concept of post acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In order to prepare the ions for the experiments singly charged radioactive ions from the on-line mass separator ISOLDE will be cooled and bunched in a Penning trap, charge bred in an electron beam ion source (EBIS) and finally accelerated in the LINAC. The LINAC consists of a radiofrequency quadrupole (RFQ) accelerator, which accelerates the ions up to 0.3 MeV/u, an interdigital H-type (IH) structure with a final energy between 1.1 and 1.2 MeV/u and three seven gap resonators, which allow the variation of the final energy. With an energy of the radioactive beams between 0.8 MeV/u and 2.2 MeV/u a wide range of experiments in the field of nuclear spectroscopy, astrophysics and solid state physics will be addressed by REX-ISOLDE.
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| 7. |
- Kester, O., et al.
(författare)
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Accelerated radioactive beams from REX-ISOLDE
- 2003
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 204, s. 20-20
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Konferensbidrag (refereegranskat)abstract
- In 2001 the linear accelerator of the Radioactive beam EXperiment (REX-ISOLDE) delivered for the first time accelerated radioactive ion beams, at a beam energy of 2 MeV/u. REX-ISOLDE uses the method of charge-state breeding, in order to enhance the charge state of the ions before injection into the LINAC. Radioactive singly-charged ions from the on-line mass separator ISOLDE are first accumulated in a Penning trap, then charge bred to an A/q
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| 8. |
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| 9. |
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| 10. |
- Prezado, Y., et al.
(författare)
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Large asymmetry in the strongest beta-transition for A=9
- 2003
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 576:1-2, s. 55-61
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Tidskriftsartikel (refereegranskat)abstract
- A new measurement of the beta-decay of Li-9 has clarified the feeding to the highest accessible states in Be-9. It is found that the P-decay mainly populates the 11.8 MeV state, whose spin is determined as 5/2(-). The extracted B-GT value of 5.3(0.9) is a factor 4.4(1.0) larger than that of the mirror transition from C-9. A theoretical explanation of such a pronounced beta-decay asymmetry is presently lacking. (C) 2003 Elsevier B.V. All rights reserved.
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