Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

Nuclear Sciences 39scattering has been done. Presently, coupled channels calculations are being carried out to explainthe data. Data analysis for inclusive α-yield is in progress.MK Pradhan, A Mukherjee, S Roy, M Saha Sarkar, VV Parkar†, S Santra†, K Ramachandran†,A Chatterjee†, S Kailas†NAP2.1.1.5 Fusion cross sections measurement of 10,11 B+ 209 BiPrecise fusion cross sections measurement has been carried out at near and above barrier energiesfor the systems 10,11 B+ 209 Bi. Both evaporation residues and fission fragments were detected at eachincident energy, using pulsed beams from the 14UD Pelletron accelerator at ANU, Australia. Fissionfragments were detected in the CUBE detector array, using a large area position sensitive multiwireproportional counter, covering laboratory angles from 95 o -170 o . However, the measurementswere restricted to the angular range 95 o -165 o , since an annular silicon surface barrier detector wasplaced 8 cm from the target, at a mean angle of 174 ◦ , to detect α-particles from the evaporationresidues. For the evaporation residue measurements, a target backed by an Al catcher foil wasused. The catcher foil thickness was chosen so as to stop the recoiling heavy residues well withinthe foil. The reaction products were identified by their distinctive α-energies and half lives. Thismeasurement has been done to study the effect of breakup of 10 B on the fusion cross sections. Dataanalysis is in progress.A Mukherjee, LR Gasques†, M Dasgupta†, DJ Hinde†, RG Thomas†NAP2.1.1.6 Study of reaction mechanisms of 16 O+ 40 Ca reactions at E ( 16 O)=86 MeVthrough measurement of light charged particlesIn continuation of the work with 28 Si + nat Si system published in the previous report we took upthe work on the 16 O+ 40 Ca using the Pelletron facility of IUAC, New Delhi. The present systemproduces the same compound nucleus 56 Ni at the same excitation energy by an appropriate choiceof beam energy. Light charged particles produced in the reaction were measured over a wide angularrange (54 0 to 138 0 ). The analysis of the spectra were carried out using the statistical model codesboth in terms of an average evaporation phenomena and an event by event build up of the angulardistributions. The latter description is able to explain the spectra and angular distributions in amuch better way than the evaporation mechanism. No entrance channel dependence was observedfrom our analysis as reported by some recently published works.Chinmay Basu, S Adhikari, SK Ghosh, S Roy, S Ray†, BR Behera†, SK Datta†NAP2.1.1.7 Reaction mechanisms with loosely bound nuclei 7 Li+ 6 Li at extreme forwardangles in the low energy regionReaction mechanisms with loosely bound nuclei 7 Li+ 6 Li were investigated in the incident energyrange E( 7 Li)=14-20 MeV at forward angles (0 ◦ , 3 ◦ , 5 ◦ , 10 ◦ , 20 ◦ , 30 ◦ ). Thick target technique wasutilized for 0 ◦ and other extreme forward angle measurements in order to avoid the beam interference.The normalized yields important for angular distributions were obtained from published