الفهرس | Only 14 pages are availabe for public view |
Abstract The track structure theory (TST), developed by Robert Katz and co-workers over 50 years ago, gives the “full” predictions for both physical and biological systems. The work in this thesis is classified into 4 chapters as follows: Chapter 1: Is an introduction to the interaction of charged particles with matter and the track formation and ion track effects as a result of the emission of secondary electrons (δ-rays) of enough energy was presented and the literature models were given. These secondary electrons’ range-energy (R-E) relations were gathered, and the corresponding radial dose distribution, RDD, formulas were given. Chapter 2: Annular energy distribution per nm, AED is a concept introduced to map the energy (dose) delivered by the secondary electron around the ion path in the 2π directions. AED was calculated for a wide range of ions (185) of different energies (from 1 to 200 MeV/n) forming 10 different equal LET groups (from LET= 4.2 to LET=1000 keV/μm) in a water target. Based on Katz (radial dose distribution) and Butts-Katz & Tabata R-E relations, a simulation model was developed for radial and annular energy distributions, Butts-Katz was used for the calculations and is recommended for such study. Annular energy distribution, AED variation with the annular width 𝑟 = 0.1 (𝑛𝑚) → 𝑟 = 𝑅𝑚𝑖𝑛(𝑛𝑚) for the different ions shows a clear peak at a specific width called the maximum annular energy width, rMAEW, and studied with the ion’s relative velocity, β2. The ratio of rMAEW of a given ion to the VI corresponding effective range, Reff was determined as 𝑟MAEW ≈ 63% Reff. Total annular energy distribution, TAED is a new concept introduced, it integrates the energy delivered by secondary electrons at all shells in the width between 𝑟 = 0.1 (𝑛𝑚) ⟶ 𝑟𝑀𝐴𝐸𝑊(𝑛𝑚) and it studied with the ion (Z*/ β)2 |