Electron interaction with gel dosimeters: effective atomic numbers for collisional, radiative and total interaction...

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Materials Science

Background:

• The effective atomic number (Zeff) is crucial for understanding radiation interactions in materials like dosimeters and biological tissues.
• Gel dosimeters uniquely function as both phantom and dosimeter materials, necessitating accurate Zeff characterization.
• Previous Zeff studies have not comprehensively covered various polymer gel dosimeters.

Purpose of the Study:

• To calculate the effective atomic numbers for total and partial electron interaction processes in Fricke and polymer gel dosimeters for the first time.
• To compare the Zeff of these gel dosimeters with biological materials across a wide energy spectrum.
• To assess the suitability of gel dosimeters as tissue substitutes in radiation studies.

Main Methods:

• Calculated effective atomic numbers (Zeff) for total and partial electron interaction processes.
• Investigated Fricke gel, hypoxic polymer gels, and normally oxygenated polymer gels.
• Analyzed a broad energy range from 10 keV to 100 MeV.

Main Results:

• Effective atomic numbers were computed for various gel dosimeters and biological materials.
• Zeff values for the studied gels closely approximate those of soft tissue over the 10 keV to 100 MeV energy range.
• Discrepancies between gel Zeff and soft tissue Zeff were generally within 4%, particularly at higher energies.

Conclusions:

• The calculated effective atomic numbers confirm that gel dosimeters exhibit close tissue equivalence.
• These findings support the use of gel dosimeters as reliable substitutes for biological tissues in radiation dosimetry.
• The study provides essential data for optimizing radiation therapy and diagnostic imaging techniques.