Abstract
The 6He+209Bi reaction displays a remarkably large cross section for α-particle emission at energies near the Coulomb barrier. The possible reactions that may produce the observed α particles include two-neutron transfer, one-neutron transfer, and direct projectile breakup. Each of these mechanisms results in a distinctive angular correlation between the α particle and outgoing neutron(s). A neutron-α-particle coincidence experiment was performed to separate these different modes. The neutron data show significant angular correlations. Monte Carlo simulations of one-neutron transfer are compared with the experimental data. It is shown that approximately 20% of the observed α-particle yield is due to this process.
Highlights
The 6He + 209Bi reaction displays a remarkably large cross section for α-particle emission at energies near the Coulomb barrier
The radioactive nucleus 6He has been widely studied because its neutron halo greatly affects the manner in which it interacts with other nuclei
It has been suggested that oneand two-neutron transfer processes might play a decisive role because preliminary calculations [8] indicate that neutron transfer can be significantly enhanced by coupling to continuum states in reactions of weaklybound nuclei such as 6He
Summary
The conclusion from these experiments was that the sub-barrier fusion of 6He with high-Z targets is significantly enhanced In another investigation [8] of 6He + 209Bi reactions at energies near the Coulomb barrier, especially large yields of α particles were observed. There are three possible mechanisms that could yield an α particle: two-neutron transfer followed by evaporation, oneneutron transfer followed by 5He breakup, and direct projectile breakup. Each of these reactions has a distinctive neutron angular distribution relative to the direction of the emitted α particle.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
