| 1. |
- Aleksandrov, D., et al.
(författare)
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Halo excitations in fragmentation of He-6 at 240 MeV/u on carbon and lead targets
- 2000
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Ingår i: Nuclear Physics A. - 0375-9474. ; 669:1-2, s. 51-64
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Tidskriftsartikel (refereegranskat)abstract
- Dissociation of a 240 MeV/u beam of He-6, incident on carbon and lead targets, has been studied in kinematically complete experiments to investigate low-lying excitation modes in the halo nucleus He-6. It is shown that alignment effects characterize the inelastic scattering and allow an unambiguous assignment of the spin of a narrow resonance observed in the excitation energy spectrum. The differential cross sections for the He-6 inelastic scattering on carbon and lead targets were deduced from the measured moments of the two neutrons and the a-particle. An analysis of these distributions shows that quadrupole and, possibly, monopole excitations characterize the hadronic interaction, while the dipole mode is dominating in Coulomb dissociation. Neither theoretically predicted new resonance states in He-6 nor nuclear excitation of a dipole mode were found. Direct evidence has been obtained for strong suppression of Coulornb post-acceleration in direct Coulomb breakup in a lead target.
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| 2. |
- Baumann, T., et al.
(författare)
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Longitudinal momentum distributions of C-16,C-18 fragments after one-neutron removal from C-17,C-19
- 1998
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 439:3-4, s. 256-261
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Tidskriftsartikel (refereegranskat)abstract
- The fragment separator FRS at GSI was used as an energy-loss spectrometer to measure the longitudinal momentum distributions of C-16,C-18 fragments after one-neutron removal reactions in C-17,C-19 impinging on a carbon target at about 910 MeV/u. The distributions in the projectile frames are characterized by a FWHM of 141 +/- 6 MeV/c for C-16 and 69 +/- 3 MeV/c for C-18. Th, results are compared with experimental data obtained at lower energies and discussed within existing theoretical models. (C) 1998 Elsevier Science B.V. AU rights reserved.
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| 3. |
- Bergmann, U. C., et al.
(författare)
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Analysis of decay data from neutron-rich nuclei
- 2001
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Ingår i: European Physical Journal A. - 1434-601X .- 1434-6001. ; 11:3, s. 279-284
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Tidskriftsartikel (refereegranskat)abstract
- The beta -decays of the neutron-rich nuclei Be-12 and Ne-29 have been studied. The statistical correlations between the almost identical half-lives of Be-12 and its daughter B-12 are analysed for a large sample of Be-12 decay data. Stringent mutual bounds are obtained on the parameter set, leading to a precise determination of the Be-12 half-life of 21.50 +/- 0.04 ms. From a simultaneous detection of beta -particles and neutrons from the decay of Ne-29 the neutron emission probability, P-n, is determined to 17 +/- 5%. No indication of two-neutron emission is seen from this nucleus. An upper limit of 2.2% (90% confidence level) is established for P-2n.
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| 4. |
- Bergmann, U. C., et al.
(författare)
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On the beta-decay of C-9
- 2001
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Ingår i: Nuclear Physics A. - 0375-9474. ; 692:3-4, s. 427-450
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Tidskriftsartikel (refereegranskat)abstract
- In beta -decay experiments on C-9 at CERN/ISOLDE the beta -strength was determined to the ground state, the 12.2 MeV excited state and the Isobaric Analog State (IAS) at 14.655 MeV in B-9. A large beta -strength asymmetry is deduced for the mirror transitions of C-9 and Li-9 to states around 12 MeV excitation energy. A satisfactory description of the three-body decay from a narrow energy region around the 12.2 MeV resonance is obtained within a sequential model involving the ground and first-excited states of Li-5 and Be-8. From the study of angular correlations the spin of the 12.2 MeV state is determined as 5/2(-). For the first time the population of the IAS is observed in beta -decay and new information on the decay of this state is obtained. The advantages of a closely packed. highly segmented detector setup are demonstrated. (C) 2001 Elsevier Science B.V. All rights reserved.
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| 5. |
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| 6. |
- 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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| 7. |
- De Oliveira Santos, F., et al.
(författare)
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Study of 19Na at SPIRAL
- 2005
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 24:2, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- The excitation function for the elastic-scattering reaction p( 18 Ne, p) 18 Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in the unbound nucleus 19 Na. In addition, two-proton emission events have been identified and are discussed.
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| 8. |
- Gard, Anna, et al.
(författare)
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Widespread White Matter Abnormalities in Concussed Athletes Detected by 7T Diffusion Magnetic Resonance Imaging
- 2024
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc.. - 0897-7151 .- 1557-9042.
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Tidskriftsartikel (refereegranskat)abstract
- Sports-related concussions may cause white matter injuries and persistent post-concussive symptoms (PPCS). We hypothesized that athletes with PPCS would have neurocognitive impairments and white matter abnormalities that could be revealed by advanced neuroimaging using ultra-high field strength diffusion tensor (DTI) and diffusion kurtosis (DKI) imaging metrics and cerebrospinal fluid (CSF) biomarkers. A cohort of athletes with PPCS severity limiting the ability to work/study and participate in sport school and/or social activities for ≥6 months completed 7T magnetic resonance imaging (MRI) (morphological T1-weighed volumetry, DTI and DKI), extensive neuropsychological testing, symptom rating, and CSF biomarker sampling. Twenty-two athletes with PPCS and 22 controls were included. Concussed athletes performed below norms and significantly lower than controls on all but one of the psychometric neuropsychology tests. Supratentorial white and gray matter, as well as hippocampal volumes did not differ between concussed athletes and controls. However, of the 72 examined white matter tracts, 16% of DTI and 35% of DKI metrics (in total 28%) were significantly different between concussed athletes and controls. DKI fractional anisotropy and axial kurtosis were increased, and DKI radial diffusivity and radial kurtosis decreased in concussed athletes when compared with controls. CSF neurofilament light (NfL; an axonal injury marker), although not glial fibrillary acidic protein, correlated with several diffusion metrics. In this first 7T DTI and DKI study investigating PPCS, widespread microstructural alterations were observed in the white matter, correlating with CSF markers of axonal injury. More white matter changes were observed using DKI than using DTI. These white matter alterations may indicate persistent pathophysiological processes following concussion in sport.
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| 9. |
- Jeppesen, H. B., et al.
(författare)
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News on beta delayed particle emission from Be-14
- 2002
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Ingår i: Progress of Theoretical Physics Supplement. - 0375-9687. ; :146, s. 520-524
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Konferensbidrag (refereegranskat)abstract
- Beta delayed charged particles from Be-14 have been measured and give an upper limit on beta delayed alpha particles of B(betaalpha)
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| 10. |
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