Relativistic electron interaction parameters of medically significant polymers have been determined by measuring their mass stopping power in transmission geometry. Using Cs137 and Bi207 IC electrons in a narrow beam good geometry set-up, the incident and transmitted electrons were recorded with Si(Li) detector coupled to an 8K MCA. Experimentally determined effective atomic number for electron interactions have been compared with that computed by direct method for both electron and photon interactions. The stopping cross section and effective electron density values are determined from mass stopping power and effective atomic number. Validity of these interaction parameters over a wide range of relativistic energy up to 10 MeV is discussed.
Interaction parameter; Mass stopping power; Effective atomic number; Effective electron density; Polymers
Hubbell.J.H., Review of photon interaction cross section data in the medical and biological context. Physics in Medicine and Biology,1999;44(1):R1-R22.
Ramesh Babu. S, Hosamani. M. M., Mirji. S, Badiger. N.M, Determination of effective Atomic Number of Some Biomolecules for Electron Interaction, IOSR Journal of Applied Physics (IOSR-JAP) 8(III), 23 (2016a) .
URL: http://www.iosrjournals.org/iosr-jap/papers/ Vol8-issue3/Version-3/D0803032327.pdf”
ICRU Report 35. Radiation Dosimetry: Electron Beams With energies between 1 to 50 MeV. 1984, DOI:10.1093/jicru/os18.2.Report35
ICRU report 37. Stopping Power for Electrons and Positrons. 1984, 10.1016/0168-583X(85)90718-9
ESTAR, PSTAR and ASTAR: Computer Program for Calculation of Stopping Power and Range Tables for Electron, Proton and Helium Ions (version 1.2.3) (2005). URL: http://physics.nist.gov/Star
White. D. R, An analysis of the Z-dependence of photon and electron interactions. Phys. Med.Biol. 1977; 22(2): 219
Taylor M L, Franich R D, Trapp J V, Johnston P N (2009), Electron Interaction with Gel Dosimeters: Effective Atomic Numbers for Collisional, Radiative and Total Interaction Processes , Radiation Research 171(1):123. DOI: 10.1667/RR1438.1
Taylor.M.L., Robust Determination of Effective Atomic Numbers for Electron Interactions with TLD-100 and TLD-100H Thermo Luminescent Dosimeters, Nuclear Instruments & Methods in Physics Research -B 269(8), 770(2011),
Parthasaradhi.K, Rao.B.M., Prasad.S.G., Effective Atomic Numbers of Biological Materials in the Energy Region 1 To 50 MeV for Photons, Electrons and He Ions , Medical Physics 16(4), 653 (1989), URL:http://dx.doi.org/10.1118/1.596325
Kurudirek.M, Onaran.T., Calculation of Effective Atomic Number and Electron Density of Essential Biomolecules for Electron, Proton, Alpha Particle and Multi-Energetic Photon Interactions , Radiation Physics and Chemistry 112, 125 (2015).
Prasad.S.G, Parthasaradhi.K, Bloomer.W.D, Effective Atomic Numbers of Composite Materials for Total and Partial Interaction Processes for Photons, Electrons and Protons, Medical Physics 24(6), 883 (1997) URL:http://dx.doi.org/10.1118/1.598001
Hine. G. ,Secondary Electron Emission and Effective Atomic Numbers. Nucleonics. 1952; 10(1): 9
Ramesh Babu.S, Badiger.N.M, Semi Empirical Formula to Calculate MSP of Relativistic Electrons in the Range of 940 keV-1020 keV, Journal of Radiation Research &Applied Sciences 9(1), 78 (2016).URL:http://www.sciencedirect.com/science/article/pii/S1687850715001107