短语词组短语plasma ring confinement 等离子体环形约束plasma confinement time 等离子体约束时间Improved plasma confinement 改善等离子体约束Magnetic confinement plasma thruster 磁约束等离子体推进器magnetic confinement of plasma 等离子区的磁密封;等离子体磁约束 返回 plasma confinement