Development of a new electronic personal neutron dosemeter using a CMOS active pixel sensor

Area of Science:

• Nuclear Physics
• Particle Detection
• Sensor Technology

Background:

• CMOS active pixel sensors (APS) are established tools for charged particle tracking in high-energy physics.
• Neutron detection traditionally relies on bulky and less versatile methods.
• There is a need for compact, efficient, and electronic neutron detection systems, particularly for personal dosimetry.

Purpose of the Study:

• To investigate the feasibility of using a CMOS active pixel sensor for fast neutron detection.
• To evaluate the intrinsic efficiency of the sensor for neutron detection.
• To assess the potential of this technology for developing a novel personal neutron dosimeter.

Main Methods:

• Utilized a CMOS active pixel sensor originally designed for particle tracking.
• Conducted experiments at the IRSN Cadarache facility using an Americium-241/Beryllium (Am-Be) neutron source.
• Employed a polyethylene radiator to enhance neutron interactions.
• Validated experimental results with MCNPX Monte Carlo simulations and theoretical calculations.

Main Results:

• Achieved a high intrinsic efficiency of 1.2 x 10⁻³ for fast neutron detection.
• Experimental data showed good agreement with theoretical calculations.
• MCNPX Monte Carlo simulations corroborated the obtained efficiency values.
• Demonstrated the sensor's capability to detect fast neutrons effectively.

Conclusions:

• The CMOS active pixel sensor shows significant promise for fast neutron detection.
• The achieved efficiency is comparable to simulation and calculation predictions.
• This research validates the potential for a fully electronic personal neutron dosimeter based on CMOS APS technology.