Keywords: 
• 快点火 /
• 预压缩 /
• 超强激光等离子体相互作用

Abstract: Fast ignition is a recently proposed new scheme for realizing ignition of inertial confinement fusion, in which the compression of an implosive capsule and its ignition proceed separately. First, the fusion pellet is precompressed by multiple beam lasers in the conventional way to a high density, then ignition is realized by a single ultraintense laser beam (of Iλ2≈1018—20 Wμm2／cm2). Fast ignition is superior to traditional `hot spot ignition' in many aspects in the precompression stage; it drastically reduces the energy required for precompression(about ten times), relaxes the requirement of drive uniformity, and is able to reach higher energy gain. However, ignition by ultraintense laser is very complicated. It involves boring a hole in the precompressed plasma, generating intense hot electrons with MeV energy, transporting them in the dense plasma and heating the high-density core to meet ignition conditions. These problems are briefly discussed and the possibility of ignition with laser energy less than 100kJ is explored.