Backscatter factors for x-rays generated at voltages between 10 and 100 kV

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Computational Physics

Background:

• Accurate backscatter factor (BSF) data is crucial for radiation dose calculations.
• Existing BSF data may not cover the range of X-ray energies and phantom compositions relevant to modern diagnostic imaging.
• A precise definition of BSF is essential for consistent and reliable dosimetry.

Purpose of the Study:

• To compute backscatter factors for cylindrical phantoms using the Monte Carlo method.
• To investigate the influence of phantom composition (water, graphite, acrylic glass, M3) on BSF.
• To evaluate BSFs across a range of X-ray beam qualities and field sizes.

Main Methods:

• Utilized the Monte Carlo method for simulating X-ray interactions within phantoms.
• Calculated BSFs for cylindrical phantoms (33 cm diameter, 20 cm thickness) composed of water, graphite, acrylic glass, and M3.
• Simulated X-ray beams with mean energies from 7.5 to 52.0 keV (10–100 kVp) at a source-surface distance of 100 cm.
• Investigated field diameters of 2 cm, 4 cm, and 11.2 cm (equivalent to a 10x10 cm square field).

Main Results:

• Presented BSF values for diverse phantom materials and X-ray beam qualities.
• Demonstrated variations in BSF depending on phantom composition, beam energy, and field size.
• The study provides a novel dataset of BSFs calculated with a specific definition.

Conclusions:

• The calculated backscatter factors provide valuable data for radiation dosimetry applications.
• The findings highlight the importance of considering phantom material and beam characteristics in dose calculations.
• This work contributes to a more accurate understanding of backscatter phenomena in X-ray dosimetry.