| 41. |
- Borge, M. J. G., et al.
(författare)
-
Beta-Decay to the Proton Halo State in F-17
- 1993
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 317:1-2, s. 25-30
-
Tidskriftsartikel (refereegranskat)abstract
- In the first experiment at the newly constructed ISOLDE Facility the first-forbidden beta-decay of Ne-17 into the first excited state of F-17 has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries for beta decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the F-17 state is taken into account.
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| 42. |
- Borge, M. J. G., et al.
(författare)
-
Beta-delayed multiparticle emission studies at ISOL-type facilities
- 2004
-
Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 746, s. 243-243
-
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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| 43. |
- Borge, M. J. G., et al.
(författare)
-
Beta-Delayed Proton and Alpha Emission in the Decay of Ne-17
- 1988
-
Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 490:2, s. 287-306
-
Tidskriftsartikel (refereegranskat)abstract
- The beta-delayed proton and alpha spectra from 17Ne have been studied with Si-detectors. The Gamow-Teller strength in the decay of 17Ne has been extracted and compared with a two-particle-one-hole shell-model calculation. The experimental strength is quenched by a factor of 0.82 with respect to the calculated one. Furthermore, the decay scheme has been improved and is discussed in some detail. The proton emitting levels in 17F are very broad and the line shapes are strongly influenced by phase-space effects. Interference between peaks corresponding to the same intermediate spin is a prominent feature emerging clearly with the good resolution and statistics of the present work.
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| 44. |
- Borge, M. J. G., et al.
(författare)
-
Beta-Delayed Triton Emission in the Decay of He-8
- 1986
-
Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 460:3, s. 373-380
-
Tidskriftsartikel (refereegranskat)abstract
- A β-delayed triton branch with an intensity of (0.9 ± 0.1)% has been observed in the decay of 8He. The triton energy spectrum was measured with a specially designed ΔE − E telescope. These data as well as an earlier measured β-delayed neutron spectrum cannot be explained from the known levels in 8Li, but it turns out that the main features of both the delayed triton and the delayed neutron spectra from 8He could be understood if one assumes a new state in 8Li at about 8.8 MeV excitation energy.
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| 45. |
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| 46. |
- Borge, M. J. G., et al.
(författare)
-
Elucidating halo structure by beta decay: beta gamma from the Li-11 decay
- 1997
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 55:1, s. R8-R11
-
Tidskriftsartikel (refereegranskat)abstract
- New values for the gamma ray intensities following the beta decay of Li-11 are presented. Special emphasis is put on the determination of the Gamow-Teller transition Li-11 --> Be-11 (1/2(-), 320 keV) to the only bound excited state in Be-11. We show that a shell-model calculation can simultaneously reproduce the half-life of Li-11 and the newly measured branching ratio to the 1/2(-) state provided the Li-11 ground state wave function contains about 50% of s-wave neutron components.
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| 47. |
- Borge, M. J. G., et al.
(författare)
-
ISOLDE past, present and future
- 2017
-
Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 44:4
-
Forskningsöversikt (refereegranskat)abstract
- The idea of production of short-lived radioisotopes with the on-line technique has it roots in the early 1950s. In 1964 this became a reality when CERN approved an experiment at the 600 MeV proton synchro-cyclotron, the SC. The first experiments were performed in 1967 and since then the ISOLDE programme has gradually developed into a major undertaking. Since 1992 the ISOLDE Radioactive Beam Facility is linked to an external proton beam from the PS Booster. Today this 50 years old `lady' is more vital than ever. With the successful start of HIE-ISOLDE in 2015 one may conclude that the facility is ready to face the next half century with the boost of the success and the necessary knowledge to face new challenges. In this introductory article we give an overview of the history and pick up a few examples along the nuclear chart as illustrations of the experimental achievements.
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| 48. |
- Borge, M. J. G., et al.
(författare)
-
Limits on Neutrino-Mixing from the Internal Bremsstrahlung Spectrum of I-125
- 1986
-
Ingår i: Physica Scripta. - 1402-4896 .- 0031-8949. ; 34:6A, s. 591-596
-
Tidskriftsartikel (refereegranskat)abstract
- The massive antineutrino recently reported by Simpson in an experiment on tritium decay has not been confirmed by experiments on 35S decay. As an independent check, we report here the negative result of a search for the corresponding antiparticle (a massive neutrino) using the decay of 125I. As a by-product, we give accurate data on internal-bremsstrahlung spectra which we have followed over close to four decades in intensity, and we report a new way of measuring its E1/M1 ratio. The experiment provides a new and very accurate value for the 125I-125Te mass difference of 186.1 ± 0.3 keV.
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| 49. |
- Borge, M. J. G., et al.
(författare)
-
Probing the Li-11 halo structure through beta-decay into the Be-11(*) (18 MeV) state
- 1997
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 613:3, s. 199-208
-
Tidskriftsartikel (refereegranskat)abstract
- An experimental study of beta-delayed charged particles (H, He, Be) from Li-11 shows a beta-feeding to an excited state at 18.15(15) MeV in Be-11 with a large Gamow-Teller strength, B-GT greater than or equal to 1.6. Branching ratios and reduced widths of 2-, 3- and 5- particle decay channels of this state are extracted, A strong suppression of the neutron branch from the 18 MeV state to the Be-10(g.s.) is observed, We suggest that the measured partial width may be sensitive to the (p(1/2))(2) component in the Li-11 halo, A rough estimate indicates that the (p(1/2))(2) component is not the dominant one in the halo wave-function.
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| 50. |
- Borge, M. J. G., et al.
(författare)
-
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
-
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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