Granular jumps commonly develop in avalanches, landslides and industrial processes when flowing grains encounter an obstacle or a slope change. A primary characteristic of such jumps is a drop in velocity and an increase in flow thickness. The non-uniformity of the features within the corresponding flows necessitates novel experimental techniques to study them, especially considering the high velocities associated with gravity-driven flows. To address this point, this study presents an X-ray analysis of the complex flow characteristics of stationary granular jumps generated by a conveyor belt setup. The experimental setup consists of a horizontal flume with a conveyor belt as the base driving the granular material motion. On the starting side, a tank with a gate of a known height H controls the incoming flow flux. At the other end, a wall produces the jump upon contact with the flow by stopping an excess of grains of height >H placed within the chute at the beginning. The incoming and outflowing heights are made equal so that, eventually the jump remains steady and stationary, while still being sheared at the bottom. Once steady, the jump is recorded using X-ray radiography from the top and the side. Obtained radiographs show that the incoming flow is essentially a bulk flow, with some shearing developing at the interface between the steady jump and the bottom flow. Notably, some three-dimensional effects are visible, with a variation of the jump elevation across the chute, which points at secondary flows. This is further analyzed using the combination of orthogonal radiographs. Additionally, a method is developed to expose the 3D shape of the surface of the jumps. Likewise, they allow to uncover the 3D velocity field in the flow direction. The setup is easily reproducible, making it ideal for future systematic tests.