| 1. |
- Markenroth, Karin, 1973, et al.
(författare)
-
Crossing the dripline to N-11 using elastic resonance scattering
- 2000
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 6203:3
-
Tidskriftsartikel (refereegranskat)abstract
- The level structure of the unbound nucleus N-11 has been studied by C-10+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a C-10 beam with an energy of 9.0 MeV/ nucleon. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the C-10+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27(-0.05)(+0.18) MeV (Gamma = 1.44 +/- 0.2 MeV), 2.01(-0.05)(+0.15) MeV (Gamma = 0.84 +/- 0.2 MeV), and 3.75 +/- 0.05 MeV (Gamma = 0.60 +/- 0.05 MeV) with the spin-parity assignments I-pi=1/2+,1/2,-,5/2+, respectively. Hence, N-11 is shown to have a ground state parity inversion completely analogous to its mirror partner Be-11. A narrow resonance in the excitation function at 4.33 +/- 0.05 MeV was also observed and assigned spin parity 3/2-.
|
|
| 2. |
- Axelsson, L., et al.
(författare)
-
Study of the unbound nucleus 11N by elastic resonance scattering
- 1996
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813 .- 2469-9985 .- 2469-9993. ; 54:4, s. 1511-1514
-
Tidskriftsartikel (refereegranskat)abstract
- Resonances in the unbound nucleus 11N have been studied, using the resonance scattering reaction 10C+p. The data give evidence for three states above the 10C+p threshold with energies 1.30, 2.04, and 3.72 MeV. These states can be interpreted, in a potential-model analysis, as the ground state and the first two excited states with spin-parity 1 / 2+, 1 / 2-, and 5 / 2+ arising from the shell-model orbitals 1s1 / 2, 0p1 / 2, and 0d5 / 2. A narrow state superposed on a broad structure found at higher energy could be interpreted as the mirror state of the 3 / 2- in 11Be shifted down in energy. This shift would suggest a large radius of the potential.
|
|
| 3. |
|
|
| 4. |
- Giovinazzo, J., et al.
(författare)
-
4D-imaging of drip-line radioactivity by detecting proton emission from 54mNi pictured with ACTAR TPC
- 2021
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.
|
|
| 5. |
- Giovinazzo, J., et al.
(författare)
-
Proton 3D tracking and emission time from a short-lived isomer with ACTAR TPC
- 2022
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1042
-
Tidskriftsartikel (refereegranskat)abstract
- An experiment was conducted at the GANIL/LISE3 facility to produce the 10+ isomer of 54Ni and measure its proton radioactivity decay branches. The proton detection was achieved with the ACTAR TPC device that enabled the separation of the small signal of the emitted proton from the large signal of the implanted ion, while the decay half-life is of the order of 150 ns. From the measured data, the emitted proton track length and the decay time of the ion can be extracted simultaneously. The full proton radioactivity pattern could be established, with two emission branches and their relative branching ratio. Data processing and analysis that allowed to identify and separate the ion and the proton signals in order to reconstruct the particles trajectories and decay time are detailed. The evaluation of the detection efficiency for the proton radioactivity branches based on a full simulation is described.
|
|
| 6. |
- Girard-Alcindor, V., et al.
(författare)
-
New narrow resonances observed in the unbound nucleus F 15
- 2022
-
Ingår i: Physical Review C. - : American Physical Society (APS). - 2469-9985 .- 2469-9993. ; 105:5
-
Tidskriftsartikel (refereegranskat)abstract
- The structure of the unbound F15 nucleus is investigated using the inverse kinematics resonant scattering of a radioactive O14 beam impinging on a CH2 target. The analysis of H1(O14,p)O14 and H1(O14,2p)N13 reactions allowed the confirmation of the previously observed narrow 1/2- resonance, near the two-proton decay threshold, and the identification of two new narrow 5/2- and 3/2- resonances. The newly observed levels decay by 1p emission to the ground of O14, and by sequential 2p emission to the ground state of N13 via the 1- resonance of O14. Gamow shell model (GSM) analysis of the experimental data suggests that the wave functions of the 5/2- and 3/2- resonances may be collectivized by the continuum coupling to nearby 2p- and 1p-decay channels. The observed excitation function H1(O14,p)O14 and resonance spectrum in F15 are well reproduced in the unified framework of the GSM.
|
|
| 7. |
- Axelsson, L., et al.
(författare)
-
Deriving the angular variation of p(parallel to)-distributions for halo neutrons with robust statistics
- 2001
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 679:3-4, s. 215-230
-
Tidskriftsartikel (refereegranskat)abstract
- The longitudinal neutron momentum distribution from core breakup of Li-11 and Be-11 have been measured at 29.9 MeV/u and 38.5 MeV/u, respectively. Separate measurements on Li-9 and Be-10 allowed extraction of the halo neutron distribution. The shapes of the distributions are analyzed using robust and descriptive statistics, For both isotopes the shape is changing with angle. (C) 2001 Elsevier Science B.V. All rights reserved.
|
|
| 8. |
- Caceres, L., et al.
(författare)
-
Nuclear structure studies of F-24
- 2015
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 92:1
-
Tidskriftsartikel (refereegranskat)abstract
- The structure of the F-24 nucleus has been studied at GANIL using the beta decay of O-24 and the in-beam.-ray spectroscopy from the fragmentation of Na-27,Na-28, Ne-25,Ne-26, and Mg-29,Mg-30 nuclei. Combining these complementary experimental techniques, the level scheme of F-24 has been constructed up to 3.6 MeV by means of particle-gamma and particle-gamma gamma coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned.
|
|
| 9. |
- Grevy, S., et al.
(författare)
-
Core-breakup reactions of the halo nuclei Be-11 and Li-11: momentum distributions and shadow effects
- 1999
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 650:1, s. 47-61
-
Tidskriftsartikel (refereegranskat)abstract
- The halo nuclei Be-11 and Li-11 have been studied in core-breakup reactions where the halo neutrons are expected to be released without a major distortion due to the reaction. The widths of the halo-neutron momentum distributions have been extracted in coincidence with He fragments, Gamma = 32 +/- 4 MeV/c, and Li fragments, Gamma = 42 +/- 4 MeV/c for Be-11 and with He fragments, Gamma =42+/-6 MeV/c for Li-11. The Be-11 breakup gives a very low neutron multiplicity of 0.38+/-0.09 which is a manifestation of the shadowing of the neutron in the core-breakup reaction. This value can be understood from a simple theoretical calculation, which also accounts for the observed transverse momentum widths at small angles. (C) 1999 Elsevier Science B.V.
|
|
| 10. |
- Marques, F. M., et al.
(författare)
-
Neutrons from the breakup of C-19
- 1996
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 381:4, s. 407-412
-
Tidskriftsartikel (refereegranskat)abstract
- Neutrons arising from the breakup of a 30 MeV/nucleon C-19 beam on a tantalum target have been measured using the 98 element array DEMON. A narrow, forward peaked neutron angular distribution, with a corresponding momentum spread considerably smaller than those measured simultaneously for N-21, O-22 and F-24 was observed for charged fragments with Z
|
|
