Transformable geometry for rapid in-situ gamma monitoring: Transformable in-situ gamma monitoring (TRIGAM) system

In-situ radiation monitoring is important in evaluating nuclear incidents, facilitating the prevention and management of accidents. Conventional in-situ detectors comprise a single detection module. However, the limited geometric adaptability of single-detector systems renders the surveillance of contaminated regions at inaccessible sites or with unconventional shapes challenging. Moreover, the narrow detection area of the conventional detectors necessitates repeated measurements to encompass accident sites comprehensively. This study introduces a transformable in-situ gamma monitoring (TRIGAM) system for 1D and 2D scanning and high-resolution imaging. The TRIGAM system incorporates eight detectors, each linked to an extendable and rotatable arm, enabling the modification of the system's shape through adjustments in the distance and angles between detectors to suit specific user applications. Compared to single-detector systems, the TRIGAM system enables faster monitoring over large areas and enhanced sensitivity at sites with unconventional geometries by adjusting geometric configuration. Moreover, TRIGAM enables 2D imaging with 5.72° image resolution using Compton camera technique imaging. For source localization in 3D imaging, 8 % and 12 % position error was observed with a source distance of 1 m and 5 m when using 3D imaging and triangulation technique, respectively. In summary, the TRIGAM offers a highly adaptable solution for in-situ radiation monitoring.