为了产生大尺度氘团簇用于与强激光相互作用研究,研制了低温高背压团簇源.利用瑞利散射法对团簇尺度与气体背压相关性和团簇的形成演变过程进行了研究.得到团簇尺度Nc随背压的指数变化关系为Nc∝P0^2.89,当气体温度为80K,背压P0为48×10^5Pa时,氘团簇尺度Nc≈2630,并得到了团簇尺度随时间变化的特性曲线.这些结果对分析激光与团簇相互作用过程,优化激光打团簇靶时间有重要意义.
We have developed and carried out a detailed characterization of a cryogenically cooled (80 K) high-pressure (50 × 10^5 Pa) solenoid driven pulsed valve that has been used to produce dense jets of deuterium atomic clusters for interaction studies with high intensity laser. Rayleigh scattering was employed to investigate the scaling law between cluster size and upstream gas pressure, which was shown to be of the form Nc ∝ P0^2.89 . Cluster size gets to its peak Nc ≈ 2630 at 80 K,48 × 10^5 Pa. We also studied the cluster formation process, portrayed a characteristic curve which revealed cluster size temporal evolution. Our results are important for analyzing the cluster interaction with intense laser, and are expected to provide guidelines to choose proper fire time.