近年來，雷射蒸射(laser ablation)的方法被廣泛地運用在各式各 樣薄膜成長的製程上，而藉由雷漿特殊的環境，可以改善此方法 所形成超微薄膜的結構與緊密度。我們運用這個技術到微粒電漿 系統中鍍膜時，意外的在光學顯微鏡下觀察到脈衝雷射所引發的 電漿塵爆，便對這個有趣的動態行為展開研究。 在微粒電漿系統中，調控適當的系統參數可以使粒子間的庫 倫耦合力大於熱力作用，而形成懸浮在電漿阱中的微粒庫倫團。 藉由實驗室成熟的微米尺寸電漿微粒觀測技術，我們首次觀察到 由脈衝雷射聚焦在局限阱底板所引發電漿微粒的爆炸過程。也測 量在不同環境下雷射蒸射的電性反應和相關參數的變化，並探討 細部動態行為的形成原因和可能機制。本文將對此及實驗結果做 一詳細的分析和闡述。在實驗過程中，我們也發現了其他有趣的 物理現象，如微粒電漿系統中的雙層位能結構和在兩種不同介質 的交界面上所形成的波的傳播，都值得做更進一步的研究。 The dust cluster with hundreds of micro-meter sized dust particles can be suspended in a rf discharge. The particles are negatively charged, which turns the system into a strongly coupled Coulomb system. Sudden expansion of the cluster is observed for the first time by introducing Nd-YAG laser pulses through the center of the cluster to the bottom plate. It is well know that after an intense short laser pulse hitting the target (aluminum), the ablated plume is formed near the surface. The sudden expansion could be caused by the strong electron emission from the electrode boundary, the ablated plasma with the ejected molecules or the sudden excitation of electrons from the dust surface. The detailed dynamical behaviors of the expansion will be demonstrated and discussed in the thesis. Furthermore, we study the influence on the expansion due to the different target and also find some interesting physical phenomena during the expanding processes in our experiment.
