Optimization and testing of groove-shaped grid-controlled modulated X-ray tube for X-ray communication

The current modulated X-ray source for X-ray communication (XCOM) are facing the problems of low bandwidth and weak X-ray intensity. In this paper, a groove-shaped grid-controlled modulated X-ray tube (GGMXT) with hot-cathode was proposed to improve the modulation performance. With cut-off voltage and tube current as objective function, a CST-Matlab co-simulation based on the non-dominated sorting genetic algorithm II (NSGA-II) was developed to optimize the grid structure of GGMXT. The simulation results shows that the cut-off voltage of GGMXT can be controlled between −71 and −3 V with corresponding X-ray intensity of 99.0% to 54.8% of the maximum value. Based on the optimized results, four different prototypes of GGMXT, including three optimized tubes and one non-optimized tube, were prepared, tested, and compared with the simulated version. The effectiveness of the optimization method was demonstrated through testing. Compared with the non-optimized tube, one optimized GGMXT prototype obtains a relatively low cut-off voltage of −5 V@50 kV while maintaining high X-ray emission intensity. Its modulation bandwidth is higher than 3 MHz and the X-ray pulse repetition rate is in excess of several MHz. Therefore, the optimized GGMXT shows excellent modulation signal emission performance and great application potential in the field of X-ray communication.