Positron stopping power in some biological compounds for intermediate energies with generalized oscillator strength model

Abstract

In this study total inelastic differential cross section and related stopping power expressions for positron were obtained by using generalized oscillator strength model. The stopping powers of low atomic number targets and of some biological compounds for positrons were calculated over the energy range from 50 eV to 10 MeV. Calculations of the stopping powers (SPs) for some low atomic number targets: H 2 , C, N 2 , O 2, P and for biological compounds: C 5 H 5 N 5 (adenine), C 5 H 5 N 5 O (guanine), C 5 H 5 N 3 O (cytosine), C 5 H 6 N 2 O 2 (thymine), C 20 H 27 N 7 O 13 P 2 (cytosine-guanine), and C 19 H 26 N 8 O 13 P 2 (thymine-adenine), have been evaluated for incident positrons in the 50 eV-10 MeV energy range. A detailed comparison of the calculated results with the other theoretical and experimental data for these target materials were presented. The calculated results of stopping powers for positrons in energy range from 50 eV to 10 MeV were found to be in good agreement to within 5% above 100 eV energies with other theoretical results.

Positron-impact electronic excitations and mass stopping power of H2

“…Many applications require accurate stopping power values at low and intermediate energies [15][16][17] for modeling the projectile's entire path through media. Attempts were made to extend semiclassical calculations of the stopping power to lower energies by using the generalized oscillator strength model [18]. However, an accurate estimate of the stopping power at low and intermediate energies requires calculations of cross sections for all important energy-loss channels such as excitation, ionization and Ps formation.…”