Total reaction and neutron-removal cross sections of(30–60)AMeVHe and Li isotopes on Pb

Abstract

Total reaction cross sections R of (30-60)A MeV 4,6,8 He and 6,7,8,9,11 Li on Pb, and 2n-removal cross sections Ϫ2n of 6,8 He and 11 Li on Pb, were measured by injecting magnetically separated, focused, monoenergetic, secondary beams of those projectiles into a telescope containing Pb targets separated by thin Si detectors. All these R 's ͑except 4 He͒, and Ϫ2n for 6 He and 11 Li, are underpredicted by microscopic model calculations which include only nuclear forces. Better agreement is achieved by including electromagnetic dissociation in the model, for those projectiles for which either the electric dipole response functions or the dominant photodissociation cross sections were known. The cross sections Ϫ4n for 8 He, Ϫxn for 7,8,9 Li, and ( Ϫ3n ϩ Ϫ4n ) for 11 Li were found to be р0.7 b. All R 's were measured to better than 5% accuracy, showing that the method is usable for other target elements sandwiched into a Si telescope.

Total reaction cross sections measurement for 6,8He and 8,9Li nuclei with energies of (25–45)/A MeV on natAl and natPb

“…3 for weakly bound 6,8 He (a, b) and 8,9 Li (c, d) neutron halo nuclei on the nat Al and nat Pb targets. Filled data points are from this experiment and open data points are from [5][6].…”

“…1. The view of the fragment separator COMBAS [8]; right top window: the picture of the used detector tele scope. The COMBAS separator allows generating the cocktail of the secondary beam and ΔE-ΔE-E (CsI) tele scope was used both to the particle identification and detection of the reaction products from the used secondary targets.…”

“…Preliminary results of measured total reaction cross sections σ R for weakly bound 6,8 He and 8,9 Li on the nat Al and nat Pb targets at energies (25-45)/A MeV were compared to the available literature data. The measured values of σ R agree with existing data.…”

“…Measurements of the total reaction cross sections σ R for weakly bound 6,8 He, 8,9 Li with energies of (25⎯45)/A MeV on nat Al and nat Pb targets were carried out. Secondary beams of 6,8 He and 8,9 Li were produced by bombardment of the 11 B (33 A MeV) beam on a Be (89 mg cm -2 ) target and separated by the COMBAS fragment separator (Fig.…”

“…Secondary beams of 6,8 He and 8,9 Li were produced by bombardment of the 11 B (33 A MeV) beam on a Be (89 mg cm -2 ) target and separated by the COMBAS fragment separator (Fig. 1) [8].…”