Towards customizable thin-panel low-Z detector arrays: electrode design for increased spatial resolution ion chamber...

Area of Science:

• Medical Physics
• Radiation Detection Technology
• 3D Printing Applications

Background:

• Ion chamber arrays are crucial for accurate radiation dosimetry.
• Existing detector arrays can be limited by spatial resolution and cost.
• 3D printing offers a novel approach for fabricating custom detector geometries.

Purpose of the Study:

• To prototype a 3D-printed ion chamber array with scalable design for enhanced spatial resolution and active area.
• To fabricate a custom-sized, thin-panel detector array using low-Z materials.
• To demonstrate the feasibility of a low-cost, 3D-printed radiation detector array.

Main Methods:

• A 30x30 air-vented ion chamber array was 3D-printed using PLA (polylactic acid) and conductive PLA for electrodes.
• The detector features a 122 mm x 120 mm active area with 4x4 mm^2 spatial resolution and a 10 mm thickness.
• Data acquisition utilized a scheme of biasing selected rows and reading 30 chambers simultaneously.

Main Results:

• The 3D-printed ion chamber array demonstrated satisfactory agreement with reference doses for 1D and 2D dose mapping.
• Discrepancies were observed in the penumbra region and field size dependence due to thin chamber walls and scattering effects.
• The study confirmed the feasibility of radiation detector arrays with minimal readout channels and low-cost electronics.

Conclusions:

• 3D printing is a viable method for prototyping scalable ion chamber arrays with potential for improved dosimetry.
• Limitations related to inter-chamber walls and scattering require further investigation for clinical accuracy.
• The demonstrated acquisition scheme facilitates rapid testing of custom detector arrays, paving the way for future advancements.