Development of Versatile Environmental Cell for Electron Microscope

密闭式环境池(EC)已投入实际使用，用于用标准电子显微镜观察水化样品。(1)封闭式EC的改进和ECT中气体压力估算的确认封闭式EC的新设计是为了将气层厚度控制在0~0.2 mm，以便于高分辨率观察和保持极薄的液层。对于封闭式EC来说，密封膜是电池最重要的组成部分，因为它必须承受高于大气压的压力，因为EC在大气条件下关闭。提出了一种高耐压、高电子透过率的最佳封闭膜的制备方法。为了提高EC实验的效率，我们还制作了密封膜耐压测试装置。对于高分辨率…为了观察到更多的离子，在密封电池之前，做了一个预排空装置，将气体压力设置为低于大气压。电池中气体层的厚度可以根据作为电子路径质量厚度的函数绘制的透过率值来估计，该电子路径包括两个密封膜和气体层。该方法可用于估算在近自然环境中观察生物标本时细胞内液层的厚度。(2)多用途薄膜密封式环境细胞及气体控制装置的研制为实际应用，改进了薄膜密封式EC结构和气体压力控制系统。通过减少EC的组件，EC变得更容易组装和处理。此外，高压密封膜可以使EC中气体压力的控制过程变得简单，因此我们制作了一种新的气体控制装置来简化操作。为了使EC具有更广泛的用途，制作了小电极单元并安装到EC中。气体循环管道可以作为导线的通道，并在EC中形成一定的电场。通过使用电极单元，可以有效地收集电子照射到EC中的气体分子产生的离子，该技术不仅可以设置EC中的气体环境，还可以通过平衡EC中的气体供应和排气速度来控制EC中的一些液体环境和液层厚度。这项技术对于水化样品的原位观察一定是有用的工具。较少

The closed type environmental cell (EC) has been put into practical use for observing the hydrated specimens with the standard electron microscopes. Based on this design of the closed type cell, the film-sealed type EC for versatile use has been developed.(1)Improvement of the closed type EC and confirmation of the estimation of the gas pressure in the ECThe closed type EC was newly designed to control the gas layer thickness from 0 to 0.2mm for observation with high resolution and for holding very thin liquid layer. For the closed type EC, the sealing film is the most important component of the cell because it must withstand the pressure higher than the atmospheric pressure when the EC is closed in the atmospheric condition. We developed the method for the best sealing film with high withstanding pressure and high electron transmittance. We also made the device for testing the withstanding pressure of the sealing films for improving the efficiency of the EC experiment.For high resolut … More ion observations, a pre-evacuation unit was made to set the gas pressure lower than the atmospheric pressure before sealing up the cell. The thickness of the gas layer in the cell can be estimated from the transmittance value plotted as the function of the mass thickness of the electron path, involving two sealing films and the gas layer. This method may be applied to estimate the thickness of the liquid layer in the cell for observing the biological specimens in the nearly natural environment.(2)Development of the film-sealed type environmental cell for versatile use and the gas control unitFor the practical use, the configuration of the film sealed type EC and the gas pressure control system were improved. By reducing the components of the EC, it became easy to assemble and handle the EC. In addition to this, the sealing film of high withstanding pressure could make the procedure of controlling the gas pressure in the EC simple, so we made a new gas control device to make the operation easy.For versatile use of the EC, small electrode unit was made and fitted into the EC. The pipes for gas circulation can be used as the passages for the conducting wires and some electric field can be made in the EC. With the use of the electrode unit, it was confirmed that the ions, produced by the electron irradiation to the gas molecules in the EC, can be collected efficiently.This technique can set not only the gas environment, but also some liquid environment in the EC and the thickness of the liquid layer can be controlled by balancing the speed between supplying and evacuating the gas in the EC. This technique must be useful tool for in-situ observation of hydrated specimens. Less