Research on rail crack detection based on diamond nitrogen-vacancy color center

Abstract The rapid growth of China’s railway industry has posed challenges to the maintenance and safety of railway infrastructure. Traditional inspection methods have struggled to detect small cracks accurately. To address this issue, this paper proposes a rail crack detection method that utilizes diamond nitrogen-vacancy color centers. By magnetizing the rail using an excitation coil and leveraging the high sensitivity and high-resolution magnetic measurement characteristics of the diamond NV color center, the system can detect the leakage magnetic field on the rail surface and complete rail crack detection. Experimental results demonstrate that the system has a magnetic measurement sensitivity of 7 nT/√Hz, and it can detect cracks as small as 0.1 mm in width, 0.1 mm in depth, and 1 mm in length.