| 1. |
- Nilsson, Thomas, 1965, et al.
(author)
-
He-6 and neutron momentum distributions from He-8 in nuclear break-up reactions at 240 MeV/u
- 1996
-
In: Nuclear Physics A. - 0375-9474. ; 598:3, s. 418-434
-
Journal article (peer-reviewed)abstract
- Neutron and He-6 momentum distributions from He-8 break-up reactions in a C target have been measured at 240 MeV/u. The two-neutron removal cross section was found to be sigma(-2n) = 0.27 +/- 0.03 b. The nature of the momentum distributions is interpreted in some simple reaction scenarios.
|
|
| 2. |
- Anne, R., et al.
(author)
-
Dissociation Reactions of the Be-11 One-Neutron Halo - the Interplay between Structure and Reaction-Mechanism
- 1993
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 304:1-2, s. 55-59
-
Journal article (peer-reviewed)abstract
- The angular distributions of the forward neutrons in the exclusive (Be-10 + n) channel have been measured. They can be accounted for quantitatively and without free parameters in terms of Coulomb and diffraction dissociation. The results show that the transverse momentum distributions result from an interplay between the tail of the wave function (the halo) and the reaction mechanism.
|
|
| 3. |
- Anne, R., et al.
(author)
-
Exclusive and Restricted-Inclusive Reactions Involving the Be-11 One-Neutron Halo
- 1994
-
In: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 575:1, s. 125-154
-
Journal article (peer-reviewed)abstract
- Reactions of a 41 MeV/u beam of the radioactive halo nucleus Be-11 have been studied with a counter telescope coupled to an array of neutron detectors covering angles up to 97-degrees. The technique allows to determine single-neutron inclusive and exclusive angular distributions. The targets (Be, Ti and Au) were chosen to illustrate the relative roles played by nuclear and Coulomb mechanisms. The channels leading to Be-10, the dissociation channels, correspond to impact parameters larger than the sum of the radii of the target and the Be-10 core. It is shown that for the dissociation process it is possible to account almost quantitatively for the integral, single- and double-differential cross sections from models without free parameters including the Coulomb, Serber and Glauber (diffraction-dissociation) mechanisms. The neutron distributions from the nondissociative reaction channels show little individuality and it is convenient to group them together as the channel ''neutron plus anything different from Be-10''. We refer to these as ''restricted-inclusive'' reactions. These seem to be a promising tool for obtaining accurate information on the halo wave function in momentum coordinates.
|
|
| 4. |
|
|
| 5. |
- Anne, R., et al.
(author)
-
Projectile Coulomb-Excitation with Fast Radioactive Beams
- 1995
-
In: Zeitschrift fur Physik A Hadrons and Nuclei. - 1431-5831 .- 0939-7922. ; 352:4, s. 397-401
-
Journal article (peer-reviewed)abstract
- We report a search for gamma rays emanating from Coulomb excitation of fast (30-46 MeV/u) radioactive projectiles He-8, Be-11,Be-12,Be-14 interacting with a lead target. These are clearly identified by their Doppler shift. The 320 keV 1/2(-) --> 1/2(+)gamma transition from Be-11 was observed with a cross-section of 191 +/- 26 mb which is noticeably less than expected from the known lifetime and in the perturbation limit of pure Coulomb excitation. In the other nuclei rather stringent upper limits of 0.01 to 0.2 Weisskopf units, are placed on the hypothetical transition to 1(-) states.
|
|
| 6. |
- Humbert, F., et al.
(author)
-
Longitudinal and Transverse-Momentum Distributions of Li-9 Fragments from Break-up of Li-11
- 1995
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 347:3-4, s. 198-204
-
Journal article (peer-reviewed)abstract
- Transverse and longitudinal momentum distributions of Li-9 fragments from Li-11 break-up reactions in C, Al and Pb targets have been measured at 280 MeV/u. The two-neutron removal cross-section was measured to be sigma(-2n), = 0.26 +/- 0.02 b for the carbon target, sigma(-2n) = 0.47 +/- 0.08 b for the aluminum target and sigma(-2n), = 1.9 +/- 0.4 b for the lead target. No significant difference is observed between the narrow widths (FWHM approximate to 47 MeV/c) of the transverse and longitudinal momentum distributions of the Li-9 fragments. The physical implications of this are discussed.
|
|
| 7. |
- Keller, H., et al.
(author)
-
Search for Forbidden Beta-Decays of the Drip-Line Nucleus Be-12
- 1994
-
In: Zeitschrift fur Physik A Hadrons and Nuclei. - 1431-5831 .- 0939-7922. ; 348:1, s. 61-62
-
Journal article (peer-reviewed)abstract
- Beta-coincident gamma-rays have been measured from implanted pure samples of Be-12 separated at the LISE3 spectrometer at GANIL. An intensity of 0.040(26)% can be estimated for the branching ratio of the isospin forbidden pure-Fermi transition to the 0+ excited state of B-12 and of 0.008(6) % of the transition to the 1- excited state. Both are taken to represent upper limits. The halflife has been re-measured to be 26.1(2.4) ms.
|
|
| 8. |
- Marques, F. M., et al.
(author)
-
Neutrons from the breakup of C-19
- 1996
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 381:4, s. 407-412
-
Journal article (peer-reviewed)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
|
|
| 9. |
|
|
| 10. |
- Nilsson, Thomas, 1965, et al.
(author)
-
Neutron Momentum Distributions from Core Break-up Reactions of Halo Nuclei
- 1995
-
In: Europhysics Letters. - 0295-5075 .- 1286-4854. ; 30:1, s. 19-24
-
Journal article (peer-reviewed)abstract
- Neutron angular distributions from violent break-up reactions of Li-11 and Be-11 have been measured at 28 MeV/u and 280 MeV/u and at 41 MeV/u and 460 MeV/u, respectively. The derived neutron momentum distributions show a narrow component in transverse momentum that is within uncertainties independent of beam energy and target charge. This component is suggested to be simply related to the momentum distribution of the loosely bound halo neutron(s) in the projectiles.
|
|
