Remote sensing of high energy particle current generated by megavoltage x-rays

Area of Science:

• Medical Physics
• Radiation Detection
• Imaging Science

Background:

• Current imaging modalities like X-ray radiography and CT use bulk materials and high voltages.
• There is a need for low-profile, low-power, and non-invasive imaging and dosimetry techniques.

Purpose of the Study:

• To establish the theoretical and experimental framework for sensing high energy particle currents (HEC).
• To demonstrate HEC sensing for novel imaging and dosimetry applications.
• To compare experimental HEC measurements with simulations.

Main Methods:

• Utilized a system of complementary electrodes placed upstream and downstream of phantoms.
• Irradiated homogeneous (water) and heterogeneous (water and bone) phantoms with 6MV X-rays.
• Measured coupled signals (s1 and s2) with zero external bias and compared them to MCNP6 and CEPXS simulations.

Main Results:

• Measured signals (s1, s2) correlated with phantom water equivalent thickness (WET), confirming information about HEC distribution.
• Developed new signal metrics (α and β) for quantifying HEC sensing in heterogeneous phantoms.
• Experimental results aligned with radiation transport simulations.

Conclusions:

• HEC sensing successfully provided information about an object's internal composition.
• The developed method, using planar electrodes, accurately measured HEC distribution, matching simulation data.
• HEC sensing offers a disruptive potential for low-power, low-profile, and non-invasive imaging and dosimetry.