Using laser-driven magnetized hohlraum to make a clean X-ray radiation source without plasma filling

500-700 T axial magnetic field was generated in a cylindrical hohlraum by the interaction of high power laser with capacitor-coil target on SG-II laser facility, which was proven by B-dot probe. Magnetic field suppressed plasma filling, forming a hollow region of the plasma corona in the vacuum hohlraum, which was observed by an x-ray framing camera. Therefore, strong magnetic field is proven to effectively suppress the plasma filling in vacuum hohlraum instead of gas, making a clean X-ray radiation source for High Energy Density Physics studies.