【摘要】 利用脉宽为 650 ps,主脉冲能量仅有 40 J 的驱动激光,演示了类氖―钛离子 J=0→1, 3p→3s 跃迁、波长为 32.6 nm 的软 X 射线激光。所用能量比以前用于低 Z 元素类氖―离子 X 射线激光的驱动能量低约一个量级。为了确定类氖―钛 X 射线激光产生的驱动能阈值,进行了一系列平板钛靶的实验。实验中,靶长采用 1.8 cm,驱动源为“星光”装置输出的波长为 1.05 μm 的激光脉冲,而“预-主”脉冲间隔为 5 ns,当预脉冲能量为主脉冲能量的 1%时,X 射线激光产生的阈值能量为 40 J,当预脉冲能量为主脉冲的 9%时,阈能量则为 110 J。1%和 9%两种预脉冲条件下,波长为 32.6 nm 的类氖―钛 X 射线激光线峰值偏转角均为 5 mrad,而发散角则分别为 4 mrad 和 5 mrad。更多还原

【Abstract】 Using only 40 J of driving energy in a 650 ps main pulse, a soft-X-ray lasing on the J=0?1, 3p?3s transition in neon-like titanium ions at 32.6 nm is demonstrated. The energy used is an order of magnitude smaller than the driving energy been used previously to drive low-Z neon-like X-ray lasers. A series of experiments are made by using titanium slab targets to study the threshold for lasing in neonlike titanium when the 1.8 cm long targets are illuminated by a low-intensity prepulse 5 ns before the main optical drive pulse of the 1.05 μm Xingguang Nd-glass laser. For a 1% prepulse, the energy threshold is measured to be 40 J, which contrasts with 110 J for a 9% prepulse. In both cases, the 32.6 nm Ti lasing line peaks is 5 mrad off-axis with divergences of 4 and 5 mrad for the 1% and 9% prepulse cases respectively.更多还原