Automated data collection and analysis system for MOSFET radiation detectors

Area of Science:

• Medical Physics
• Radiation Detection
• Semiconductor Devices

Background:

• Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are utilized as radiation dosimeters due to their small size and low power needs.
• Their characteristics make them suitable for real-time dose monitoring in radiotherapy, but signal drifts pose a challenge.

Purpose of the Study:

• To design and build an automated data collection and analysis system for MOSFET radiation dosimeters.
• To enable real-time acquisition and processing of MOSFET signals in various radiotherapy radiation fields.
• To address and correct intrinsic signal drifts, particularly during low dose rate measurements.

Main Methods:

• Developed an automated system integrating a personal computer with analog-to-digital and digital-to-analog converter boards.
• Employed a single-chip programmable current supply to power MOSFET dosimeters.
• Implemented real-time or post-collection deconvolution techniques to correct signal drifts caused by ion diffusion and electron tunneling.

Main Results:

• Successfully designed and built an automated data acquisition and analysis system for MOSFET dosimeters.
• Developed methodologies to correct intrinsic and extrinsic signal drifts in MOSFET signals.
• The system effectively handles real-time data processing for accurate dosimetry.

Conclusions:

• The developed system offers a viable solution for real-time radiation dose monitoring in radiotherapy.
• Accurate dosimetry is achievable even in low dose rate applications like brachytherapy and radioimmunotherapy through drift correction.
• The system enhances the utility of MOSFET dosimeters for precise radiation dose delivery verification.