中文摘要：

采用两步激发共振光电离技术研究了Sm原子的偶宇称高激发态光谱.实验采用了两条激发路线：1）第一束激光的波长固定在478.44nm以便将Sm原子从4f66s2[7F1]态激发至4f66s6p[7D1]态,再用第二束激光使其波长从480nm扫描至530nm,将Sm原子进一步激发至待测的高激发态;2）第一束激光的波长固定在574.81nm以便将Sm原子从4f66s2[7F2]态激发至4f66s6p[5G3]态,再用第二束激光使其波长从460nm扫描至470.5nm,将Sm原子进一步激发至待测的高激发态.最后,利用第三束激光通过光电离技术对处于上述高激发态上的Sm原子进行探测.通过对光电离光谱的详细分析,测定了第一电离限以下分别处于39465—39932cm-1和40000—42010cm-1这两个能量范围内的26个和76个偶宇称高激发原子态.报道了它们的能级位置和相对光谱强度,还对其光谱归属进行了讨论.通过与文献值进行比对,发现所测定的51个原子态数据与文献相一致,而其余51个原子态则为本实验首次发现.

英文摘要：

Resonant ionization spectra of Sm atom are studied with a two-step photoexcitation and photoionization method.Two different excitation paths are carried out as the following：In the path 1,the first laser whose wavelength is fixed at 478.44 nm excites the Sm atom from the 4f66s2[7F1] state to the 4f66s6p[7D1] state,and then the second laser whose wavelength λ2 is scanned from 480 nm to 530 nm excites it further to the high-lying state with even parity.In the path 2,the first laser whose wavelength is fixed at 574.81 nm excites the Sm atom from the 4f66s2[7F2] state to the 4f66s6p[5G3] state,and then the second laser whose wavelength λ2 is scanned from 460 nm to 470.5 nm excites it further to the high-lying state with even parity.These Sm atoms in the high-lying state are probed by photoionization via the third laser.All together 26 and 76 states of Sm atom in the 39465—39932 cm -1 and the 40000—42010 cm -1 energy region,respectively,have been detected below the first ionization limit.The energy levels and relative strengths of these states have been determined.Among them,51 states are newly discovered,while the rest agree well with the values published in literature.In addition,efforts are also made to determine their spectral designation.