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Title of Thesis

Institute/University/Department Details
Department of Physics/ Gomal University Dera Ismail Khan
Number of Pages
Keywords (Extracted from title, table of contents and abstract of thesis)
heavy ion interaction, elastic scattering, grazing collisions, dissipative collisions, compound nucleus, ssntd technique

Two different projectiles 2008Pb and 197Au at the same energy (11.67 MeV/ u) have been bombarded on 197 Au target to study heavy ion interactions in off-line mode. The reaction products emerging from these interactions have been studied using mica foils as detectors. Geometrical parameters (lengths and angles) have been measured for all the observed binary as well as multi-pronged events. The binary events have been sorted into two groups of elastic and in-elastic events. The reaction cross-sections have been determined experimentally from elastic and in-elastic data respectively. Multi-pronged events have been analyzed numerically using an empirical mass-dependent velocity range relation. The kinematical analysis has been done using the internal calibration of the detectors. The intermediate stage has been constructed from the knowledge of the relative velocities of the fragments observed in the final stage of the reaction. The quantities like mass transfer, total kinetic energy loss and scattering angles in the first step of the reaction have been determined. These quantities were then used to study the intermediate stage of the reaction.

From the analysis of multi pronged events it has been observed that all the analyzed 3- and 4-pronged events were due to sequential and double sequential fission. The Q-values of the first step of the reaction as well as reaction cross-sections in various angular bins of scattering angles have been plotted to study the time scale of the existence of di-nuclear composite system in the intermediate reaction step. Moreover, the in-plane angular distributions of the fission fragments have been determined to get information about the duration of time between first and second reaction step.

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2284.77 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 contents
113.59 KB
2 1 Heavy Ion Collisions
178.08 KB
  1.1 Introduction 1
  1.2 Classification Of Heavy Ion Reactions 3
  1.3 Elastic Scattering 6
  1.4 Grazing Collisions 10
  1.5 Deep-Inelastic Or Dissipative Collisions 12
  1.6 Fusion Reactions And Compound Nucleus Formation 15
3 2 SSNTD Technique For The Study Of Heavy Ion Interactions
288.6 KB
  2.1 Experimental Techniques For The Heavy Ion Interaction Study 17
  2.2 Details Of SSNTDs 22
  2.3 Historical Background Of Heavy Ion Collisions Using SSNTD Technique 27
  2.4 Computerized Autoscanning System 31
4 3 Track Formation Models And Criteria For Track Formation In SSNTDS
138.03 KB
  3.1 Formation Of Charged Particle Tracks In Insulating Materials 36
  3.2 Track Formation Models 37
  3.3 Range-Energy Relation 40
  3.4 Range In Complex Media 41
  3.5 Criteria For Track Formation 42
5 4 Experimental Details
178.41 KB
  4.1 Principle Of Track Detection Technique 48
  4.2 Sample Preparation 50
  4.3 Scanning And Measurements 51
  4.4 Separation Of Elastic Events 51
  4.5 Kinematical Analysis 55
  4.6 Selection Of Coefficients Cμν For Range- Energy Relation 56
6 5 Results And Discussion
457.03 KB
  5.1 Reaction Cross-Section 63
  5.2 Some Other Reaction Parameters 67
  5.3 Distance Parameter D 0 71
  5.4 Analysis Of Multi-Pronged Events 73
  5.5 Conclusions 106
7 6 References 108
1136.09 KB
  6.1 References