Low dose rate γ-ray detection using a MAPS camera under a neutron radiation environment

Area of Science:

• Nuclear instrumentation and radiation detection.
• Sensor technology for extreme environments.

Background:

• Accurate radiation detection is crucial in complex nuclear environments, often involving mixed neutron and gamma-ray fields.
• Traditional detectors may require specialized shielding or conversion layers, complicating integration into systems like robotics.

Purpose of the Study:

• To evaluate the capability of a monolithic active pixel sensor (MAPS) camera for gamma-ray detection within a neutron radiation environment.
• To assess the sensor's sensitivity to neutrons and single photons without additional shielding or conversion materials.
• To identify key sensor response metrics for quantifying radiation dose rates.

Main Methods:

• Utilized a monolithic active pixel sensor (MAPS) camera directly in a mixed neutron and gamma-ray radiation field.
• Analyzed the sensor's output signal, comprising pedestal, noise, and radiation response.
• Correlated the number of pixels exceeding a specific signal threshold (100) with the radiation dose rate.

Main Results:

• The MAPS camera demonstrated sensitivity to both neutrons and individual photons.
• The sensor's output signal was a composite of inherent sensor characteristics and the radiation response.
• A strong correlation was observed between the dose rate and the count of pixels with signals above 100, identifying it as a reliable indicator.

Conclusions:

• Monolithic active pixel sensor (MAPS) cameras can function as effective radiation detection sensors in mixed-field environments.
• The technology offers a viable solution for radiation monitoring in robotic systems, reducing human exposure and error.
• The proposed method provides an efficient means for dose rate estimation using pixel signal counts.