Laarmann T, Rusek M, Wabnitz H, Schulz J, de Castro A R B, Gürtler P, Laasch W, Möller T
Max-Born-Institute, Max-Born Strasse 2a, D-12489 Berlin, Germany.
Phys Rev Lett. 2005 Aug 5;95(6):063402. doi: 10.1103/PhysRevLett.95.063402.
The ionization dynamics of Ar and Xe clusters irradiated with intense vacuum ultraviolet light from a free-electron laser is investigated using photoelectron spectroscopy. Clusters comprising between 70 and 900 atoms were irradiated with femtosecond pulses at 95 nm wavelength (approximately 13 eV photon energy) and a peak intensity of approximately 4 x 10(12) W/cm2. A broad thermal distribution of emitted electrons from clusters with a maximum kinetic energy up to 30-40 eV is observed. The observation of relatively low-energy photoelectrons is in good agreement with calculations using a time-dependent Thomas-Fermi model and gives experimental evidence of an outer ionization process of the clusters, due to delayed thermoelectronic emission.
利用光电子能谱研究了用自由电子激光产生的强真空紫外光辐照氩和氙团簇的电离动力学。用波长为95nm（光子能量约为13eV）、峰值强度约为4×10¹²W/cm²的飞秒脉冲辐照由70至900个原子组成的团簇。观察到团簇发射电子的热分布很宽，最大动能高达30 - 40eV。相对低能光电子的观测结果与使用含时托马斯 - 费米模型的计算结果吻合良好，并为团簇的外层电离过程提供了实验证据，这是由延迟热电子发射引起的。
