1：Experimental Design and Method Selection:

The point-type CNT field emitter was fabricated by dispersing and purifying SWCNT in SDS solution, filtering the CNT solution on an AAO membrane, dissolving the AAO membrane in NaOH solution, and cutting the CNT film into a triangular tip shape. Field emission properties were measured in both diode and triode structures in a high vacuum chamber.

2：Sample Selection and Data Sources:

The CNT film was used as the electron beam source.

3：List of Experimental Equipment and Materials:

Equipment included a high vacuum chamber, DC power supplies (Keithley 2290 Spellman SL300 and SL1200), an oscilloscope (Tektronix TDS1012), and a small vacuum chamber with a Be window for x-ray imaging.

4：Experimental Procedures and Operational Workflow:

The DC voltage was applied to the gate, focusing, and anode electrodes, and the current was measured at the gate and anode electrodes simultaneously. X-ray images were obtained by the CNT x-ray source.

5：Data Analysis Methods:

The resolution of x-ray images was evaluated.