14C autoradiography with an energy-sensitive silicon pixel detector

Area of Science:

• Medical Imaging
• Particle Physics Instrumentation

Background:

• Digital autoradiography offers advanced imaging capabilities for radioisotopes.
• Carbon-14 (14C) is a widely used radioisotope in biological and medical research.
• Existing digital imaging detectors have limitations in sensitivity and energy resolution for beta-particle detection.

Purpose of the Study:

• To present the first performance evaluation of a novel carbon-14 beta-particle digital autoradiography system.
• To assess the capabilities of an energy-sensitive hybrid silicon pixel detector with Timepix readout for 14C imaging.
• To characterize key performance metrics including sensitivity, background, minimum detectable activity, and spatial resolution.

Main Methods:

• Utilized a hybrid silicon pixel detector (256x256 pixels, 55 µm pitch) bump-bonded to a Timepix readout circuit.
• Implemented an off-line image analysis procedure to identify single-particle charge clusters and calculate total energy.
• Measured detector sensitivity, background noise, minimum detectable activity, and spatial resolution.

Main Results:

• Achieved a detector sensitivity of (4.11 ± 0.03) × 10(-3) cps mm(-2) kBq(-1) g.
• Recorded a background level of (3.59 ± 0.01) × 10(-5) cps mm(-2).
• Determined a minimum detectable activity of 0.0077 Bq with a spatial resolution of 76.9 µm (FWHM).

Conclusions:

• The Timepix-based digital autoradiography system demonstrates promising performance for carbon-14 imaging.
• The energy-sensitive nature of the detector allows for direct energy measurements per pixel.
• The system's sensitivity and spatial resolution are competitive with existing digital imaging detectors for 14C applications.