STUDY OF THE DYNAMICS OF HIGHLY IONIZED CAPILLARY DISCHARGE PLASMAS FOR XUV LASERS

这个项目将研究高度电离的 由快速放电产生的毛细管等离子体， 探索放大极端的可能性 紫外线辐射在一个紧凑和简单的 放电装置 高效功率密度沉积 在毛细管几何形状中可以产生高度电离 具有高纵横比体积的等离子体。 大 电子热传导到毛细管壁 提供快速等离子体冷却， 电流脉冲 这些条件是理想的一个 极紫外复合激光器方案。 我们已经展示了 毛细管等离子体直径为500微米， 厘米长，温度约为30 eV 和利用放电的1 × 1018 cm-3的密度 能量只有5焦耳（1010 W/cm 3），我们有 在类氢原子中观察到的3-2跃迁的激发 等离子体复合期间的锂。 考虑 增益随Z的有利缩放， 重组等离子体，我们将研究一个 一种新型的毛细管放电， 脉冲宽度和更高的功率密度（1013 W/cm 3）， 关于放大3- BV（26.2 nm）和CVI（18.2 nm）的2个跃迁。 等离子体条件，将产生在 电流脉冲也是研究 类Ne跃迁的碰撞激发 用于产生激光的相对低Z离子 在28-70 nm光谱区的辐射。 的 等离子体电阻率的测量 独立确定等离子体密度， 温度使用XUV光谱技术和 亚皮秒激光诊断将允许研究 控制等离子体的基本物理过程 行为，并提供了一个测试的运输理论。

This project will study the dynamics of highly ionized capillary plasmas created by fast discharges and explore the possibility of amplifying extreme ultraviolet radiation in a compact and simple discharge device. Efficient power density deposition in a capillary geometry can generate highly ionized plasmas with a high aspect ratio volume. Large electron heat conduction to the capillary walls provides rapid plasma cooling at the end of the current pulse. These conditions are ideal for an extreme ultraviolet recombination laser scheme. We have already demonstrated the generation of capillary plasmas 500 micrometers in diameter and 4 cm long with a temperature of approximately 30 eV and a density of 1*1018cm-3 utilizing a discharge energy of only 5 Joules (1010W/cm3), and we have observed excitation of the 3-2 transition in hydrogenic lithium during plasma recombination. Considering the favorable scaling of the gain with Z in a recombining plasma, we will study the dynamics of a new type of capillary discharges, of shorter pulsewidths and higher power density (1013 W/cm3), in relation to the possibility of amplification of the 3- 2 transitions of BV (26.2 nm) and CVI (18.2 nm). The plasma conditions that will be generated during the current pulse are also of interest in the study of collisional excitation of Ne-like transitions of relatively low Z ions for the generation of laser radiation in the 28-70 nm spectral region. The measurement of plasma resistivity and the independent determination of the plasma density and temperature using XUV spectroscopic techniques and subpicosecond laser diagnostics will allow the study of fundamental physical processes governing the plasma behavior and provide a test for transport theories.