  A novel ignition hohlraum named 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 hohlraum are largely identical but with minor
differences with those in vacuum hohlraum. All laser energy can be totally
delivered into hohlraum in 3 ns duration even without filled gas in the
hohlraum of 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 hohlraum and gas-filled hohlraum are both lower than 2%. Experimental
study of this new kind of hohlraum can provide guidance for future target
design and implosion experiment.
