First Investigation on the Radiation Field of the Gas-Filled Three-Axis Cylindrical Hohlraum

A novel ignition hohlraumnamed three-axis cylindrical hohlraum(TACH) is designed for indirect-drive inertial confinement fusion. TACH is a kind of 6 laser entrance holes (LEHs) hohlraum, which is orthogonally jointed of three cylindrical hohlraums. The first experiment on the radiation field of TACH was performed on Shenguang III laser facility. 24 laser beams were elected and injected into 6 LEHs quasi-symmetrically. Total laser energy was about 59 kJ, and the peak radiation temperature reached about 192 eV. Radiation temperature and pinhole images in gas-filled hohlraumare largely identical but with minor differences with those in vacuum hohlraum. All laser energy can be totally delivered into hohlraumin 3 ns duration even without filled gas in the hohlraumof 1.4 mm diameter. Plasma filling cannot be obviously suppressed even with 0.5 atm pressure gas in the small hohlraum. Backscattering fractions of vacuum hohlraumand gas-filled hohlraumare both lower than 2%. Experimental study of this new kind of hohlraumcan provide guidance for future target design and implosionexperiment.