Initial results of 'Gekko 12' glass laser system on inertial fusion

The glass laser system 'GEKKO 12' has started irradiation test in November, 1983. This report gives the initial results of the start-up experiment of the system. The 'GEKKO 12' was constructed for the study of inertial fusion experiment. The characteristics are the large output energy of long pulses, the large peak output of short pulses, two target irradiation systems for one laser system, and the good stability of the system. The output energy of 1 ns pulses is 20 kJ at the time of operation. The start up experiment was performed in December, 1983. The obtained peak output was 47.5 TW. The energy balance was kept within 6 percent. The spatial pattern of short pulses was mostly homogeneous. After the fine adjustment of alignment, the energy balance became within 2 percent. The implosion experiment of targets began from December 2. The direct irradiation type and the canon ball type targets were used. The operational conditions of the laser system and the energy pattern reflected from the targets were studied. The number of neutrons from the targets was 4 x 10¹⁰, which was measured by the activation method with A l and Ag foils. The temperature of fuel was measured by the time of flight method of neutrons. (Kato, T.)