1：Experimental Design and Method Selection:

The experiment was performed at the PG2 beamline of the FLASH facility using the single bunch mode with 10 Hz repetition rate. The beam from the undulator was transmitted through a Xe gas absorber to reduce the pulse power. A diffuser made of silica nanospheres was used to generate a speckle pattern, and a transmission grating was used to split the beam into two identical branches. One branch passed through a sample, and the intensities of the bucket and reference signal were measured simultaneously by a CCD detector.

2：Sample Selection and Data Sources:

The sample was a two-slit structure with slit bars of 200 μm width and 1.5 mm height separated by 200 μm, prepared by electroplating 300 nm thick cobalt onto a 100 nm Si3N4 substrate.

3：5 mm height separated by 200 μm, prepared by electroplating 300 nm thick cobalt onto a 100 nm Si3N4 substrate. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: The equipment included a Xe gas absorber, a diffuser made of silica nanospheres, a transmission grating, a two-slit sample, and an Andor Ikon CCD detector.

4：Experimental Procedures and Operational Workflow:

The diffuser was continuously moved to vary the speckle pattern from pulse to pulse. The beam was split by the transmission grating, with one branch passing through the sample. The intensities of the bucket and reference signal were measured simultaneously by the CCD detector.

5：Data Analysis Methods:

The ghost image was reconstructed by computing the correlations between the pixelized reference area and the integral of a bucket region.