The analysis of complex mixed-radiation fields using near real-time imaging
Jonathan Beaumont1, Matthew P Mellor2, Malcolm J Joyce3
1Department of Engineering, Lancaster University, Lancaster LA1 4YR, UK j.beaumont@lancaster.ac.uk.
Radiation Protection Dosimetry
|May 1, 2014
Summary
A novel mixed-field imaging system can separately image neutron and gamma-ray radiation sources. This technique successfully located shielded and unshielded sources, demonstrating its advantage over gamma-ray-only imaging.
Area of Science:
- Nuclear instrumentation
- Radiation detection and imaging
Background:
- Passive radiation imaging systems are crucial for locating and assessing radioactive sources.
- Distinguishing between neutron and gamma-ray emissions is vital for accurate source characterization.
Purpose of the Study:
- To develop and test a new mixed-field imaging system capable of simultaneously detecting and imaging neutron and gamma-ray radiation.
- To evaluate the system's performance in locating various radioactive sources, including shielded ones.
Main Methods:
- Construction of a mixed-field imaging system utilizing collimation and back-projection principles.
- Employment of an EJ-301 liquid scintillator for real-time neutron-gamma discrimination.
- Imaging of Californium-252, lead-shielded Americium-241/Beryllium, and Sodium-22 radiation sources.
Main Results:
- Separate images of neutron and gamma-ray emitters were successfully formed.
- Californium-252 and Sodium-22 were located in the gamma-ray image.
- Americium-241/Beryllium was detected in the neutron image but not the gamma-ray image due to lead shielding, highlighting the system's mixed-field capability.
Conclusions:
- The developed mixed-field imaging system effectively locates and assesses both neutron and gamma-ray radiation sources.
- The system demonstrates a significant advantage over gamma-ray-only imaging, particularly for shielded neutron sources.
