High resolution gamma ray tomography scanner for flow measurement and non-destructive testing applications

Area of Science:

• Nuclear Engineering
• Materials Science
• Physics

Background:

• Industrial processes require detailed visualization of internal flow dynamics and phase distributions.
• Nondestructive testing (NDT) of dense materials demands high-resolution imaging techniques.
• Existing gamma ray tomography systems may have limitations in spatial resolution or detector technology.

Purpose of the Study:

• To develop and characterize a high-resolution gamma ray tomography scanner.
• To enable detailed scientific studies of flow regimes and phase fraction distributions.
• To provide a versatile tool for NDT of radiologically dense objects.

Main Methods:

• Utilized a Cesium-137 (Cs-137) isotopic source emitting 662 keV gamma photons.
• Employed advanced avalanche photodiode (APD) technology coupled with lutetium yttrium orthosilicate (LYSO) scintillation crystals for radiation detection.
• Developed a computed tomography scanner gantry with rotational and translational stages for flexible measurements.

Main Results:

• Achieved a spatial image resolution of 0.2 line pairs/mm at 10% modulation transfer function (MTF) with noncollimated detectors.
• The detector arc consists of 320 single detector elements operated in pulse counting mode.
• Integrated wireless local area network (WLAN) for data communication and slip rings for power supply.

Conclusions:

• The developed gamma ray tomography scanner provides high spatial resolution for critical industrial applications.
• The system is well-suited for analyzing complex flow regimes and phase distributions in reactors and pipelines.
• The scanner's capabilities extend to effective nondestructive testing of large, radiologically dense components.