Generation of a High-Density Recombining Plasma sheet with Inverted Population as a Medium for VUV Laser

以倒置粒子数作为 VUV 激光介质的高密度重组等离子体片的生成

• 批准号: 02680008
• 负责人: TAKIYAMA Ken
• 金额: $ 1.09万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02680008/
• 关键词: Recombining Plasma; Plasma Spectrosopy; Population Inversion; 再結プラズマ

The mechanism of formation of a recombining plasma as a short-wavelength laser medium by gas-contact cooling of a high temperature plasma was experimentally studied by means of the spectroscopic measurement.1) Three kinds of helium plasmas with different initial electron temperatures (T_e) and densities (n_e) were produced by a Z-pinch gun, and each was injected into the hydrogen molecular gas. The time-resolved spectra and spatial distributions in emission lines of H. He and He_+ were observed by a spectroscopic system with a fast-gated multichannel detector.2)The homogeneous mixingne of the plasma with hydrogen gas was achieved when the density of hydrogen gas exceeded the initial n_e of each plasma : At that gas density, the Stark broadening in H beta and He II 468.6nm lines showed that the atomic hydrogen felt, the same electron density as the He^+ ion did, and the spatial distribution of H beta line was also similar with that of Hell468.6nm line.3)Cooling of electron temperature induced by the mixing was observed in each plasma. The final T_e after cooling strongly depended on the initial one.4)The plasma cooled down less than 2eV was recognized to be in a recombining phase from the remarkable enhancement in the population density of the excited states of He^+ ion.Thus, it was found that the formation of the recombining plasma was obviously dependent upon the initial plasma parameters, especially T_e. Further detailed investigation is to be proceeded in order to obtain the optimum plasma condition.

用光谱测量的方法研究了高温等离子体气体接触冷却形成复合等离子体作为短波长激光介质的机理。1)用Z-Pinch枪产生了三种不同初始电子温度(T_E)和密度(N_E)的氦等离子体，并分别注入到氢分子气体中。用快速选通多道探测器的光谱系统观测了H、He和He_+发射线的时间分辨光谱和空间分布。2)当氢气密度超过每个等离子体的初始N_e时，等离子体与氢气实现了均匀的混合：在该气体密度下，Hβ和HeⅡ468.6 nm谱线的斯塔克展宽表明，原子氢感，电子密度与He~+离子相同，Hβ谱线的空间分布也与Hell468.6 nm谱线相似。3)在每个等离子体中观察到由混合引起的电子温度降温。冷却后的最终T_e强烈依赖于初始T_e。4)从He~+离子激发态布居密度的显著增加可以看出，冷却到2 eV以下的等离子体处于复合阶段。因此，复合等离子体的形成明显依赖于初始等离子体参数，特别是T_e。为了获得最佳的等离子体条件，还需要进行进一步的详细研究。

项目成果

Y.Kamiura: "Spectroscopic measurements of helium recombining plasmas produced by mixing with hydrogen gas." Spectrosc.Soc.Japan.

Y.Kamiura：“氦与氢气混合产生的重组等离子体的光谱测量。”

U.Furukane: "Contribution of Charge Exchange Process for Inverted Population in a Recombining Plasma" Jpn.J.Appl.Phys. 29. L1511-L1513 (1990)

U.Furukane：“重组等离子体中倒置电荷交换过程的贡献”Jpn.J.Appl.Phys。

K. Sato: "Effect of a duuble electron capture process on excited states of He plasma with H_2 gas." Phys. Rev. Lett.

K. Sato：“双电子捕获过程对 H_2 气体 He 等离子体激发态的影响。”

K.Sato: "Effect of a double electron capture proxess on excited states of He plasma with HCC2DD gas." Phyps.Rev.Lett.

K.Sato：“双电子捕获过程对 HCC2DD 气体 He 等离子体激发态的影响。”

Y. Kamiura: "Spectroscopic measurements of helium recombinig plasmas produced by mixing with hydrogen gas." J. Spectrosc. Soc. Japan.

Y. Kamiura：“通过与氢气混合产生的氦重组等离子体的光谱测量。”