Direct and compound reactions induced by unstable helium beams near the Coulomb barrier

Journal Article · Fri Oct 01 00:00:00 EDT 2004 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.70.044601· OSTI ID:20695662

Navin, A; Tripathi, V; Chatterjee, A; Kailas, S; Mahata, K; Ramachandran, K; Shrivastava, A ^[1]; Blumenfeld, Y; Tryggestad, E ^[2]; Nanal, V; Pillay, R G ^[3]; Simenel, C; Casandjian, J M; France, G de; Rejmund, M ^[4]; Raabe, R; Pollacco, E C; Sida, J L ^[5]; Bazin, D ^[6]; Dasgupta, M ^[7]

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1. Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
2. Institut de Physique Nucleaire, IN2P3-CNRS, F-91406, Orsay Cedex (France)
3. Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India)
4. GANIL, Boite Postale 5027, F-14076, Caen Cedex (France)
5. DSM/DAPNIA/SPhN, CEA Saclay, F-91191, Gif-sur-Yvette Cedex (France)
6. National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)
7. Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); and others

Reactions induced by radioactive {sup 6,8}He beams from the SPIRAL facility were studied on {sup 63,65}Cu and {sup 188,190,192}Os targets and compared to reactions with the stable {sup 4}He projectiles from the Mumbai Pelletron. Partial residue cross sections for fusion and neutron transfer obtained from the measured intensities of characteristic in-beam {gamma} rays for the {sup 6}He+{sup 63,65}Cu systems are presented. Coincidence measurements of heavy reaction products, identified by their characteristic {gamma} rays, with projectilelike charged particles, provide direct evidence for a large transfer cross section with Borromean nuclei {sup 6}He at 19.5 and 30 MeV and {sup 8}He at 27 MeV. Reaction cross sections were also obtained from measured elastic angular distributions for {sup 6,8}He+Cu systems. Cross sections for fusion and direct reactions with {sup 4,6}He beams on heavier targets of {sup 188,192}Os at 30 MeV are also presented. The present work underlines the need to distinguish between various reaction mechanisms leading to the same products before drawing conclusions about the effect of weak binding on the fusion process. The feasibility of extracting small cross sections from inclusive in-beam {gamma}-ray measurements for reaction studies near the Coulomb barrier with low intensity isotope separation on-line beams is highlighted.

• OSTI ID: 20695662
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 70, Issue 4; Other Information: DOI: 10.1103/PhysRevC.70.044601; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
ANGULAR DISTRIBUTION
COMPOUND-NUCLEUS REACTIONS
COPPER 63 TARGET
COPPER 65 TARGET
COULOMB FIELD
CROSS SECTIONS
DIRECT REACTIONS
GAMMA RADIATION
HEAVY ION FUSION REACTIONS
HELIUM 6 REACTIONS
HELIUM 8 BEAMS
HELIUM 8 REACTIONS
ISOTOPE SEPARATION
MEV RANGE
NEUTRON TRANSFER
NUCLEAR REACTION KINETICS
OSMIUM 188 TARGET
OSMIUM 190 TARGET
OSMIUM 192 TARGET