Trap-modulated fluoride scintillators for thermal mapping-assisted X-ray 3D tomographic imaging

Nondestructive X-ray imaging techniques provide insights into the internal structure and deformation defects of electronic components. Abnormal heating is a common phenomenon that often occurs with electronic component failure. However, the significance of invisible thermal signals is often overlooked due to the limitations of conventional scintillator and X-ray imaging techniques. Rare-earth-doped fluoride scintillators, known for their high-energy irradiation response and thermally stimulated luminescence (TSL) properties, offer the potential to simultaneously utilize thermal signals and nondestructive X-ray imaging. Herein, we present a thermal mapping-assisted X-ray 3D tomographic application based on a trap-modulated LiLuF 4 :Tb,Zn (LLF:Tb,Zn) scintillator. By controlling the trap density in the energy range of 0.66 to 1.77 eV, LLF:Tb,Zn microcrystals achieve over 60 days of X-ray energy storage and a 7.7-fold increase in TSL. Additionally, the light yield is 143 % higher than that of the previous level, and the detection limit reaches 3.83 nGy s −1 . Furthermore, utilizing refractive-index matching between LLF:Tb,Zn microcrystals and polyacrylate, a high-loading, large-area flexible scintillation film is developed for thermal and high spatial resolution X-ray imaging of electronic chips. The film has an imaging spatial resolution of 35 LP mm −1 . Finally, we demonstrate the application of LLF:Tb,Zn films for thermal mapping-assisted 3D X-ray tomography reconstruction of an electronic component, offering a novel approach to multimodal X-ray imaging.