Upgrading Neutron Imaging Facility at TRR-1/M1 Reactor

Abstract

The neutron imaging system at Thai Research Reactor 1/Modification 1 (TRR-1/M1) is located at Thailand Institute of Nuclear Technology, Bangkok. It has been developed for research on non-destructive investigation using radiography and tomography techniques. The main instruments of the system consist of a neutron camera, a sample rotation system operated by in-house developed software, and a neutron shutter remotely controlled via a WIFI switch. In the first half of 2022, the TRR-1/M1 was temporarily shut down for annual maintenance. Meanwhile, additional shielding was installed in the imaging room for improving radiation safety. The current neutron camera was replaced with a new one to improve the imaging system performance. The camera performance, such as brightness and image quality, were investigated by varying the exposure time and imaging of the resolution test pattern, Siemens star, respectively. The results showed that the new camera set has higher brightness than the old one about 41% when compared to 70% grey value of 16 bit-format. The spatial resolution of 2D and 3D images were 0.59 mm and 1.37 mm, respectively. Moreover, the additional shields could reduce the radiation level around the reactor hall about 6-7 times. Then, neutron tomography using a new camera will be conducted to present the 3D visualization of various samples.