Shells Scattered Threshold Anomaly And Near Barrier Heavy Ion Fusion

In the recent years, in heavy ion nuclear reactions at near- and sub-barriel- energy area, the phenomena of fusion cross-section enhancement, thethreshold anomaly of optica1 potential and the slope anomaly in transferreactions have been observed subsequently. Among those, fusion cross-section enhancement and optical potential anoInaly were esPeciallyinterested. All the abnormal phenomena urge the researchers to connect them,try to find the inherent cause and probe into underlying nuclear reactionmechanism In this paper, our study is just based on the above theoryWith the high quality beam provided by HI-l3 tandem accelerator, theelastic scattering of ¹⁶O+⁹⁴Zr,¹⁶O+¹¹⁶Sn , ¹⁶O+¹²⁴Sn å'Œ ¹⁶+¹⁴⁴Sm systelns atdit1brent energies has been measured Then, the angular distributions of thefOur systems were gotten The angular distributions of the systems ="O+'#Zrand "O+11'Sn have been reproduced with the coupled channel code ECISThereby, the sensitive radii of the optical potentials were determined and theel1ergy dependent re1ation of the real and imaginary potentials at sensitiveradius was obtained. The abnormal phenomena were observed initially.In this paper, we give a wraparound description of the experimentalequipment, the electronics, data acquisition as well as the analysis of theexperimenta1 data. Preliminary results were obtained after the analyzing ofthe data However, further theoretical apprehension and analysis werenecessary fOr the study of the relation between the phenomena andunderlying nuc1ear reaction mechanism.