Numerical Analysis for Effects of Irradiation Nonuniformities on Target Implosion. I. 2-Dimensional Simulation

Effects of irradiation nonuniformities on target implosion and ignition conditions for inertial-confinement fusion with ion beams are studied by using a 2-dimensional code. The following results are obtained. When the beam energy is 5 MJ which is 1.6 times the threshold beam energy (=3.2 MJ) in the spherical symmetric case, ignition occurs if the peak-to-valley nonuniformity rate is smaller than 0.05. On the otherhand, this value rises up to 0.1 when the beam energy is 7 MJ, i.e., it is 2.2 times the threshold beam energy in the spherical symmetric case. Furthermore, the ignition condition is the severest for the nonuniformity with the largest spatial scale.