Measurement of 42 MeV 7Li projectile breakup on 208Pb target near grazing incidence

✍ Scribed by Dhruba Gupta; C. Samanta; A. Chatterjee; S. Kailas; B.J. Roy; K. Mahata; A. Shrivastava

• Book ID: 104333782
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 275 KB
• Volume: 683
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(00)00452-8

✦ Synopsis

Breakup of 42 MeV 7 Li projectiles in the field of a 208 Pb target are studied near the grazing angle. In inclusive breakup measurements, angular distribution of the α and t fragments are found to be rather flat in nature. The α-t coincidence measurements are carried out with wide angular separations between the detected fragments. The choice of detection angles enables measurement in the same range of fragment relative energies but very different 7 Li * scattering angles. The direct breakup contribution is found to dominate over the sequential breakup for the θ α > θ t set, while the reverse is true when θ α < θ t . Calculations performed in a full quantum mechanical framework reproduce the overall shape of the direct breakup part of the present data and several existing data on 197 Au and 208 Pb targets at nearby energies. The sequential breakup is observed only from the decay of the 4.63 MeV (7/2 -) resonant excited state of 7 Li and its angular distribution does not fully agree with the existing theoretical predictions. Unlike the direct part, the sequential breakup cross section does not decrease with increasing scattering angles. Similar measurements with halo nuclei would be helpful to study their unknown resonant states.